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CROSS REFERENCE TO RELATED APPLICATIONS Co-Pending or Previously Abandoned Patent Applications [0001] Methods for detection of ultraviolet light reactive alternative cellular energy pigments (ACE pigments). William John Martin Submitted Dec. 24, 2007. Publication number 20090163831 Method of assessing and of activating the alternative cellular energy (ACE) pathway in the therapy of diseases. William John Martin Submitted Jan. 16, 2008. Publication number 20090181467 [0002] Enerceutical mediated activation of the alternative cellular energy (ACE) pathway in the therapy of diseases. Submitted May 8, 2008. Publication number 20090280193 [0003] Regenerative wound healing using copper-silver citrate composition. Submitted Oct. 22, 2008 Publication number: 20100099758. [0004] Enerceutical activation of the alternative cellular energy (ACE) pathway in therapy of diseases. Submitted Feb. 11, 2009. Publication number 20090202442. [0005] Method of using the body's alternative cellular energy pigments (ACE-pigments) in the therapy of diseases Submitted Feb. 20, 2009. Publication number 20100215763 [0006] Urine as a source of alternative cellular energy pigments (ACE-pigments) in the assessment and therapy of diseases. Submitted Mar. 5, 2009. Publication number 20100196297 [0007] Moringa oil mediated activation of the alternative cellular energy pathway in the therapy of diseases. Submitted Feb. 24, 2010. Publication number 20110208110. [0008] Activation of the alternative cellular energy (ACE) pathway in the therapy of diseases. Submitted Jun. 9, 2010. Publication number 20110306917. [0009] Methods for the detection of alternative cellular energy (ACE) pigments and for monitoring of the ACE pathway in the diagnosis and therapy of diseases. Submitted Jun. 13, 2010. Publication number 20110306077. [0010] Diagnostic value of systemic ACE pathway activation in the detection by fluorescence of localized pathological lesions. Submitted Jul. 26, 2010. Publication number 20100291000 [0011] Enerceutical mediated activation of the alternative cellular energy (ACE) pathway in the therapy of diseases. Submitted July 2010. [0012] Method of generating hydrogen in gasoline using an enerceutical product added to magnesium in a hydrogen permeable but solute impermeable container. Submitted Jul. 18, 2008. Publication number 20100011657 [0013] Energy Charged Liquids to Enhance Enerceutical Activation of the Alternative Cellular Energy (ACE) Pathway in the Therapy of Diseases. Submitted Dec. 17, 2010. Publication number 20120152755 [0014] Energy Charged Alcoholic Beverages for Enhancing the Alternative Cellular Energy Pathway in the Prevention and Therapy of Diseases. Submitted January 2011, Publication number 20120171340. [0015] Methods for Detecting and Monitoring the Activity of Energized Water and Other Liquids Useful for Enhancing the Alternative Cellular Energy Pathway in the Prevention and Therapy of Diseases. Submitted February 2011 [0016] Methods for Increasing the Kinetic Activity of Alcohol, Water and Other Liquids, so as to Render the Liquids More Useful in Enhancing the Alternative Cellular Energy Pathway in the Prevention and Therapy of Diseases. Submitted February 2011 [0017] Methods for Increasing the Kinetic Activity of Water and Other Liquids, so as to Render the Liquids More Useful in Enhancing the Alternative Cellular Energy Pathway and in Various Other Agricultural and Industrial Applications. Submitted June 2011. [0018] Methods for Increasing the Kinetic Activity of Water and Other Liquids, so as to Render the Liquids More Useful in Enhancing the Alternative Cellular Energy Pathway and in Various Other Agricultural and Industrial Applications. Submitted October 2011. [0019] Use of Plants Extracts to Activate Water, Alcohol and Other Liquids. Submitted Oct. 27, 2011. Application Ser. No. 13/272,215. [0020] Methods of Transferring Energies to Water, Alcohols and Minerals. Submitted Nov. 25, 2011. Application Ser. No. 13/304,558. [0021] Weight Change as a Measurement of an Intrinsic Energy Property of Matter. Submitted Dec. 27, 2011. Application Ser. No. 13/340,669 [0022] Weight Change as a Measurement of an Intrinsic Energy Property of Foods and Other Materials, Submitted Jan. 5, 2012. [0023] Heat as a Method to Enhance the Fluid Activating Ability of Humic Acids, Zeolites and Related Enerceuticals, Submitted May 28, 2014. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0024] Not applicable: No Federal funding was received in support of this patent application. REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX [0025] Not Applicable BACKGROUND OF THE INVENTION [0026] As detailed in the above-listed co-pending and/or abandoned patent applications, which are herein incorporated by reference, the Applicant has identified an inducible kinetic activity of water, which relates to the water's ability to provide biological benefits beyond that of regular, non-activated water. Water activation is postulated to involve the absorption of an external force tentatively called KELEA (kinetic activity limiting electrostatic attraction). The KELEA activity of water and other fluids can be enhanced using a variety of methods, broadly categorized into two approaches. One approach involves the addition to the water of small amounts of certain unbound dipolar substances. These include humic/fulvic acids, zeolites, various other ceramics, terpenes and many others. The second approach to water activation is to place water into different types of electrical, magnetic and/or other energy fields, including that provided by previously activated fluids. In certain situations, the body itself can produce a water activating energy field, as the Applicant has now shown by including water samples near the participants engaging in Laughing Yoga classes. [0027] Activation of water can be assessed by the differing dissolving patterns of particles of neutral red dye sprinkled onto the surface of the water. These patterns can range from stationary particles with slowly enlarging concentric rings of dissolved dye (indicative of minimal kinetic activity of the water), to rapid linear movements of the particles in activated water. The linear movements typically have a to-and-fro quality and can lead to long streaks of dissolved dye. In highly activated water, grouping of particles can collectively move as a rapidly rotating, horizontal, cylindrical vortex. While dissolved particles of neutral red dye in regular water, do not yield an ultraviolet (UV) light fluorescent solution, activated water solutions with added neutral red dye will fluoresce upon UV illumination (except if the fluorescence is quenched by particular additional components in the solution). Another useful assay to assess the degree of kinetic activation of water is to measure the rate of weight loss of capped containers of the water. For non-activated water, the weight reduction even over several hours is minimal (<0.1 mg per ml). Activated water will more rapidly lose weight, which occurs primarily by evaporation of highly kinetic molecules. These molecules show the capacity to escape in spite of the screwed cap of the container. The workable threshold of significant activity (weight loss) is >0.5 mg/ml within several hours. Values of >5 mg/ml have been achieved. The increased vaporization is essentially a measure of reduced intermolecular hydrogen bonding of the water molecules and can also be also measured as an increase in vapor pressure within completely sealed containers. [0028] Activation can be shown with other drinkable fluids, including non-alcoholic and alcoholic beverages. High ethanol content alcoholic beverages have a higher baseline of activity than does water and non-alcoholic beverages, but can be induced to still much higher levels of activity. It has also been noted that a small quantity of activated fluid added to regular fluid will induce activation of the entire fluid in a time dependent manner. This type of progressive activation is typically achieved using 10 fold dilutions. It is similar to the procedure used in preparing, so called, homeopathic formulations. (The Applicant has learned through experimentation that it is preferable to allow for a day or so time delay between dilutions.) [0029] Unlike, the misleading principle that homeopathic formulations have a specificity of action under the “Law of Similars,” activated water and/or alcohol can potentially provide substantial clinical benefits for a wide range of illnesses. The clinical benefits occur through the enhancement of the body's alternative cellular energy (ACE) pathway. This can be achieved through the consumption or injection of the activated fluid. It can also occur by placing the fluid in close proximity of the body. Included in this latter approach, is the addition of a small quantity (−0.1 mg/ml) of neutral red dye into the activated water or ethanol, with the solution then being illuminated with a UV light (for example a Halco 13 watt condensed UV light bulb) for 30-60 minutes. Activation of the ACE pathway is shown by the occurrence of UV inducible fluorescence within patchy areas the patient's skin and/or within the oral cavity. [0030] There are increasing clinical data supporting the proposal that enhancing the ACE pathway can help compensate for illnesses characterized by an insufficiency of cellular energy derived from food metabolism. These conditions include inadequate oxygen from chronic obstructive pulmonary disease (COPD); impaired blood supply from cardiovascular and cardiovascular diseases; and increased energy demands due to infections and during wound healing. Of further interest is the indication that the ACE pathway plays a more unique role, beyond that of food calories, in supporting human cognition and mood. [0031] This new paradigm has placed special importance on increasing the efficiency and availability of ways of enhancing the ACE pathway. It has also stimulated inquiry into the physics of the proposed KELEA force. The working hypothesis is that KELEA is attracted by free (unbound) electrical charges and may be fundamental in preventing the fusion and possible annihilation of opposing electrical charges. It is envisioned that certain dipolar (dielectric) compounds can capture and then release (transmit) KELEA in an oscillating manner, such that nearby electrostatically bonded water molecules will undergo a degree of charge separation. This loosening of intermolecular hydrogen bonding can be sufficient to enable the separated water molecules to function as direct receivers of KELEA. The body water includes both intracellular and extracellular water, with the latter including blood, lymph and cerebrospinal fluid. BRIEF SUMMARY OF THE INVENTION [0032] The invention underscores the distinction between the use of various dietary products as sources of calories and/or biochemical nutrients and their discovered function of much smaller amounts being able to activate water and both non-alcoholic and alcoholic beverages. The patent application does so by describing water and beverage activation by a wide range of products, including certain dietary supplements, pharmaceutical compounds and natural foods. Included in the later is cocoa, an ingredient used to make chocolate. Once the water or beverage is activated, the activating product can be substantially removed by progressive dilutions (as in the practice of homeopathy) or completely removed by highly efficient filtration. The requirement for very small amounts (<1 mg/ml) of activating product is emphasized since it is often more efficient than using larger amounts (>10 mg/ml) of product. These findings will likely result in the widespread adoption of using activated water for human and animal consumption, as well as improving the efficiency of agriculture and of certain water based industrial applications. The terms “enerceuticals”; “waterceuticals”; “alternative cellular energy”; “ACE Water” and “KELEA Activated Water” convey the essence of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0033] Not Applicable and none included DETAILED DESCRIPTION OF THE INVENTION [0034] To formally establish that water itself is being activated, many of the water activation studies described in the Applicant's earlier patent applications using tap water have been repeated using distilled water (e.g. Arrowhead Distilled Water supplied by Nestlé). The focus of this Application is on the successful use of dietary supplements and certain foods, including cocoa, as practical means of activating water and both non-alcoholic and alcoholic beverages. The level of water activation is primarily assessed by progressively weighing the treated distilled water in capped, but not completely sealed 1 oz glass containers. (A 200 gm electronic digital Sartorius balance reading to 0.1 mg is used in most weighing experiments.) Both the rate and extent of weight loss occurring over several hours and in some experiments over days and even over many months have been made. (As noted previously, while the weight of containers with regular water remains essentially stable [<0.1 mg/ml loss over several hours]; the weight of containers with activated water will exceed >0.5 mg/ml over the same period of time and may typically continue to >1.0 mg/ml within 24 hours.) This approach can be followed by testing for the ability of ˜10% of the activated water to induce significant weight loss in a secondary container with 90% added regular distilled water. [0035] The other major parameter of water activation is testing for dynamic linear and to-and-fro dissolving patterns of sprinkled neutral red dye particles, which remain on the surface of the water. This dynamic pattern contrasts with the slowly, concentrically spreading dissolving pattern seen when neutral red dye is sprinkled onto inactive water. (An exception to this test is when the surface tension of the activated water is so reduced that the neutral red dye particles become submerged and the dissolving dye tends to be less linear). Another useful criterion of activation is UV light fluorescence of solutions of activated water with dissolved neutral red dye (˜0.1 mg/ml). The fluorescence does not occur with solutions of inactive water and dissolved neutral red dye. [0036] Absolute ethanol and very high alcohol content beverages, such as Stroh Rum (80% ethanol) or EVERCLEAR grain alcohol (75.5% ethanol) will naturally show a dramatic dissolving pattern of neutral red dye and fluorescence of solutions with neutral red dye. It proceeds to a much greater extent than that of even highly activated water. Yet these activities, as well as measurable weight loss in closed containers, can still be greatly enhanced using various dipolar materials. Moreover, when dissolved humic acid is added, there is a slow formation of bubbles, which rapidly collapse. [0037] The range of compounds able to activate water and ethanol containing fluids is ever increasing. Moreover, the efficiency of humic acids, zeolites, kaolin and other ceramics in activating either water or beverages can be significantly enhanced by heating to ˜1,000° C. or higher in either a vacuum furnace or an inert gas filled furnace. (The heating is intended to disrupt covalent bonds in favor of unbound electrical charges). A method practiced over the last several months with supporting clinical evidence of efficacy has been the activation of Stroh Rum in a 500 ml bottle using 50 mg of humic acid, which had previously been subjected to an hour of heating at 1,000° C. Eighty (80) ml aliquots of activated rum (80% ethanol) are removed at various times and diluted to 800 ml with distilled water, to achieve an 8% ethanol solution. Eighty (80) ml of this diluted solution is further diluted 10 fold the next day to achieve a 0.8% ethanol solution and on the next day diluted 2 fold to reach an acceptable 0.4% ethanol concentration. This material clearly tests positive in assessments of its kinetic activity, benefits of drinking, testing on plants, etc. Several layers of Glad “Cling Wrap” (Oakland Calif.) are used to help seal the tightly screwed capped containers, when not being used to dispense activated liquid. The containers of activated water are stored separately from water samples designated as control water in various testing procedures. Otherwise, the activated solutions can lead to partial activation of the nearby water. [0038] The amounts of products required for water activation using heated humic acids can be less than the 0.1 mg/ml used in the above illustration. Moreover, the removed 80 ml aliquots of activated rum can be replaced with fresh rum as it is being used, without an overall loss of activity over time. As with other particulate materials being used for liquid activation, the humic acids can be reused, if recovered from the activated fluid by sedimentation or by filtration (discussed later). [0039] Various soluble pharmaceutical products have also been shown to have water-activating properties, including small amounts of procaine, Lidocaine, niacin and Dilantin. So too can many tinctures used in the formulation of homeopathics (available from Biorin Corp. Newtown square, Pa.). Of the foods tested, extracts of leaves and/or seeds of moringa oleifera trees are effective as are leaves and stems of the Ashitaba plant. HB-101, a Japanese terpene-rich tree sap extract and d-limonene, which is derived from orange peel, can also readily activate water. Certain fermenting bacteria and yeasts also produce water activating components, but their safety has not been established. [0040] Of special interest because of its ready acceptance by the public, is the discovery of the quite remarkable water-activating activity of cocoa ( cocao ), as shown by using as little as 0.1 mg/ml of store purchased, packaged material. (Indeed, it is less effective and only active over a short period of time when large quantities (>10 mg/ml) of cocoa are added to distilled water. Cocoa is mainly derived from the fruit seeds of the Theobroma cacao tree, but can also be extracted from kola nuts and from certain tea plant leaves. Its major ingredient is theobromine, a dipolar molecule. The cocoa products tested included 8 oz and 8.8 oz packages of Chirardelli Premium Baking Cocoa and Droste Cocao, respectively. Given the small amount of cocoa required, each single package could potentially directly activate over 2,000 liters of water or beverage. A clue to the potential water activating properties of cocoa and of certain other herbal extracts is reports of their broadly based medicinal benefits. While others have attributed these benefits to the products' biochemical properties, the Applicant has discovered their biophysical capacity for activating liquids. [0041] Proof that the beneficial activity of various natural products is intrinsic to their ability to activate water and not due to their biochemistry is provided by several lines of evidence: i) comparable activation of water is achievable using external energy delivering devices; ii) the level of activity tends to be inversely related to the amount of added component, with the exception of insoluble pellets; iii) the activity is retained through several 10 fold dilutions, as practiced in homeopathy; iv) activity is retained after all of the added material is removed by filtration. A simple demonstration of the latter is obtained by using the Zero Water device manufactured by Zero Technologies, 4510 Adams Circle, Bensalem Pa. 19020, to ensure removal of the water activating components; v) the levels of water and beverage activation can steadily increase over several months if the activated liquids are maintained in tightly sealed containers and vi) sealed containers of activated liquids can be used to activate nearby fluids, without any need for direct mixing of the two liquids. [0042] Attributing the beneficial effects of using these compounds to the physics of fluid activation stands in sharp contrast to the generally accepted notions of their biological functions. For example, humic/fulvic acids and zeolites are commonly regarded as sources of bioavailable minerals. Several of the listed products are regarded as powerful anti-oxidants. Niacin is identified as a vitamin, while procaine, Lidocaine and Dilantin are thought to function as inhibitors of neurotransmission. Homeopathic tinctures are viewed to act selectively in treating the same sets of symptoms as are inducible when administered in larger quantities to normal individuals (Law of Similars). More recent concepts relating to many of the compounds include their possible intracellular influences upon gene expression (epigenetic effects). These effects can arguably lead to the increased production of certain beneficial hormones and neurotransmitters, e.g. endorphins in the case of cocoa containing chocolate. [0043] The basic discovery is that various naturally occurring materials, including cocoa, can be used in small quantities to activate fluids. These products can seemingly act as antennas to capture an environmental energy, tentatively called KELEA. Possibly, via an oscillatory mechanism, some of these compounds can undergo some adjustment so as to release the absorbed energy, which can, thereby, be transferred to nearby fluid molecules. The transmitted energy reduces the intermolecular hydrogen bonding of the fluid molecules, potentially exposing the separated charges to the direct absorption of KELEA. This can lead to further activation of the fluid over time, as has been repeatedly seen. Once this phase of continuing further activation is achieved, the remaining presence of the initial dipolar material is no longer required and can be removed by dilution or by filtration. The recovered materials can be reused. The activated fluids can also be used to activate added fluids, including water. Fluid activation can, therefore, be a highly efficient, inexpensive, process with essentially unlimited potential. [0044] The body can also produce KELEA absorbing materials, termed ACE pigments. They can be fluorescent, especially in the presence of certain dyes including neutral red dye. They are occasionally magnetic and can show alternating attraction and repulsion attraction when suspended in water. Chemically, they include various aromatic structures and can bind to various minerals. They form within cells, but may also form abiotically, along with the synthesis of lipid membranes and other structures. [0045] It is also likely that electrical charges within the body can act as KELEA absorbing materials. These can include coordinated electrical activity of skeletal muscles, heart and brain. Furthermore, there may be a complementary, positive feedback relationship between activated water and electrical activity of organs in the absorption and spreading of KELEA. This is suggested by the capacity of laughter to activate water and the ability of activated water to elevate the mood of individuals. [0046] It is reasonable to suppose that KELEA can also be diverted from its role in activating water. Microwave of homeopathic formulations is stated to diminish its beneficial activity. Compounds could absorb KELEA and either not release it, transfer it into a non-usable energy, e.g. heat. It is certainly possible that stress in some way can act as a drain on KELEA. Conceivably, it could be fast beta brain waves, tachycardia, cortisol, adrenaline, etc. [0047] The invention now being described, it will be apparent to one of skill in the art that the findings are reflective of a new paradigm. The appended claims represent a rather narrow series of immediate practical applications of the findings. Modifications and extensions of these claims will undoubtedly follow without departing from the spirit and scope of the invention.

The Applicant has identified a biological energy pathway, which is distinct from photosynthesis and from the generation of cellular energy through normal metabolism. It is referred to as the third or the alternative cellular energy (ACE) pathway. This pathway is expressed through an energy acquired kinetic activity of water molecules. The present application extends on the breadth of compounds capable of transferring a natural force called KELEA, (kinetic energy limiting electrostatic attraction) to water and to both non-alcoholic and alcoholic beverages. They include common dietary supplements such as humic acids and common foods, such as cocoa. These products can be repeatedly used for liquid activation at very low quantities and can be removed from the liquid prior to the liquid being used for biological purposes. The studies have widespread practical applications in human and animal health as well as in agriculture. The studies also provide for a better understanding of the practice of homeopathy.

GOVERNMENT RIGHTS This invention was made with United States Government support under Contract No. DE-AC04-76DP00789 awarded by the U.S. Department of Energy. The Government has certain rights in this invention. BACKGROUND OF THE INVENTION The present invention relates generally to the field of surface passivation of micromechanical structures formed on semiconductor, ceramic, oxide or metal substrates. More particularly, the present invention relates to a technique for preventing the undesirable adhesion of micromechanical structures to one another or to a substrate due to static friction (i.e. stiction). Many micromechanical structures manufactured today rely upon semiconductor etching techniques. The same techniques utilized in the electronics industry to develop integrated circuits also permit manufacturers to create a wide variety of miniaturized mechanical devices, including sensors such as accelerometers, microphones, analytical chemical systems, flow sensors, combustion sensors, and bolometers. Other micromachined devices developed by traditional semiconductor manufacturing techniques include actuators used as weapon surety devices and valves employed in flow control systems. Manufacture of micromechanical structures using typical semiconductor processing technology involves the patterning and deposition of structural layers of polycrystalline silicon (polysilicon), metal or silicon nitride on a semiconductor substrate. Sacrificial layers of silicon dioxide, polymer or metal can also be deposited and patterned on the semiconductor wafer, allowing for the formation of composite micromechanical structures. These sacrificial layers can be subsequently dissolved during an etching process, leaving the structural layers and the supporting substrate intact. The remaining micromechanical structures can rotate or translate, depending upon the design and intent of the original structural pattern. Unfortunately, the chemistries designed to release adjacent structural parts by dissolving the sacrificial layers can also cause unwanted adhesion between released adjacent structural parts or between such structural parts and the supporting substrate. The undesired adhesion or stiction that results from the use of such wet release chemistries poses a serious barrier to the manufacturing of effective micromechanical structures. When micromechanical structures touch, their extremely flat surfaces, small scales, mechanical flexibility, and the tendency for direct chemical bonding between contacting surfaces make it difficult to separate these micromechanical structures. When the micromechanical structures stick, the resulting micromechanical device is no longer functional. Various methods have been developed for the chemical passivation of semiconductor device surfaces. One method that has been developed for the passivation of micromechanical device surfaces is described in U.S. Pat. No. 5,318,928 to Gegenwart et al. The method of Gegenwart et al. calls for introducing an inert gas into a tank where a high frequency energy source is applied to internal electrodes for the ignition of a plasma within the tank. The micromechanical device surfaces are cleaned by sputtering away impurities from the surface by means of plasma particles striking the surface. Such a method is necessarily expensive due to the use of plasma enhanced depositions on the micromechanical devices, unlike the present invention which involves a simple and inexpensive wet chemical treatment process, which also avoids the harmful effects to humans and animals associated with plasma etching. Other methods for semiconductor surface passivation include those shown in U.S. Pat No. 4,910,840 and U.S. Pat. No. 4,908,805 to Sprenkels et al. The Sprenkels et al. patents provide for an electrical passivation method that is unlike the chemical surface passivation method disclosed in the present invention. Still other methods use less effective or more expensive passivation techniques such as supercritical carbon dioxide drying or foregoing the use of a non-stick release mechanism. Foregoing the use of non-stick release mechanisms in particular results in often severe yield problems. Carbon dioxide drying, in particular, involves the high pressure, super critical transition of carbon dioxide from a liquid to a gas phase. In such circumstances, costly and dangerous high pressure vessels and cryogenic liquids must be utilized to complete the passivation of a semiconductor surface. The present method of preventing micromechanical devices from adhering to another object offers many advantages over existing technologies. One advantage of the present invention is that cumbersome and potentially hazardous plasma devices are not required, thereby reducing the passivation method to a simple, yet unique and inexpensive, wet chemical passivation method. The present invention provides a method which enhances throughput, safety and economy over existing technologies. SUMMARY OF THE INVENTION A method for preventing micromechanical structures from adhering to another object. The present invention comprises a wet chemical treatment process in combination with conventional integrated circuit processing techniques. Initially, unreleased micromechanical structures, along with the substrate upon which the micromechanical structures are located are immersed in an etching agent so that the micromechanical structures can be released from one another and/or from the substrate by any supporting sacrificial layers. Subsequently, the substrate and micromechanical structures are rinsed with deionized water, thereby removing the etching agent along with any dissolved sacrificial layer material. The water can then be displaced by immersing the substrate and any micromechanical structures in alcohol. The alcohol can then be displaced by immersing the substrate and the micromechanical structures in an organic solvent, and adding hexamethyldisilazane ("HMDS") to the solvent. Further scope of applicability of the present invention will become apparent from the detailed description of the invention provided hereinafter. It should be understood, however, that the detailed description of the invention and the specific example presented, while indicating an embodiment of the present invention, is provided for illustration purposes only because various changes and modifications within the spirit and scope of the invention will become apparent to those of ordinary skill in the art from the detailed description of the invention and claims that follow. BRIEF DESCRIPTION OF THE DRAWINGS The manner in which the above recited features and advantages of the present invention are attained are illustrated in the appended drawings. FIG. 1 depicts the method steps of the present invention. FIG. 2 depicts the formation of undesirable strong bonds between structural layers. FIG. 3 depicts a treatment for preventing the formation of undesirable strong bonds between structural layers. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for preventing the undesirable adhesion of micromechanical structures to one another or to a substrate. The method of the present invention can be accomplished by immersing released micromechanical structures and the associated substrate on which the micromechanical structures were formed, into a liquid selected from a class of liquids that have the property of reacting chemically with the surfaces of the micromechanical structures and their associated substrate so as to form a layer of a surface-attached inert chemical functional group. One such inert chemical functional group is the trimethylsilyl group. Such inert chemical functional groups do not form strong chemical bonds with like functional groups upon simple direct contact. Hexamethyldisilazane is an example of a liquid selected from an inert chemical functional group. When hexamethyldisilazane is applied to a substrate and micromechanical structures, a thin film forms, approximately one molecular monolayer in thickness, which terminates in methyl groups that point away from the surfaces of the substrate and micromechanical structures. Methyl groups do not bond well to other methyl groups nor to other chemical and surface functional sites. When the surfaces of two separate micromechanical structures are coated with a monolayer that terminates in methyl groups and are subsequently placed together, the micromechanical structures will not stick to one another under ordinary ambient conditions. A first embodiment of the present invention is shown in FIG. 1. In a first step 10, unreleased micromechanical structures formed on a substrate are etched with a hydrofluoric acid based etchant so as to release the micromechanical structures. In a second step 20, the micromechanical structures and the substrate are rinsed with deionized water. In a third step 30, the deionized water is displaced with a water-miscible alcohol. In a fourth step 40, the alcohol is displaced with an organic solvent. The organic solvent is compatible with a liquid derived from an inert chemical functional group such as the trimethylsilyl group. In a fifth step 50, a liquid derived from an inert chemical functional group such as the trimethylsilyl group is added to the organic solvent to form a solution which forms a layer on the surface of the micromechanical structures so as to passivates the surface of the micromechanical structures and their associated substrate. A sixth step 60 includes drying of the substrate and the micromechanical structures. The method according to the present invention, however, is not limited to this particular sequence of steps. The method disclosed in the present invention can apply to micromechanical structures derived from polysilicon or silicon nitride and which further include sacrificial elements. Such sacrificial elements can be oxide sacrificial elements. Given a substrate with these micromechanical structures, a release can be accomplished by etching the sacrificial oxide elements and associated sacrificial layers with an appropriate etchant such as hydrofluoric acid, hydrofluoric acid buffered with ammonium fluoride, a diluted hydrofluoric acid solution, or mixtures of hydrofluoric acid and other acids such as hydrochloric acid. A dihydroxy alcohol such as ethylene glycol can also be added to this etch. Upon completion of this initial release step, the substrate and structural elements can be rinsed thoroughly with deionized water. A hydrophilic surface can then be formed by rinsing the substrate and the micromechanical structural elements with a diluted aqueous ammonia solution. The reaction of the diluted aqueous ammonia solution with the substrate forms the hydrophilic surface. After the formation of the hydrophilic surface, a secondary rinse of the substrate and structural elements can be performed with deionized water. The deionized water can be subsequently displaced with a water-miscible alcohol such as isopropanol, ethanol or methanol. The alcohol can then be displaced with an organic solvent such as acetone that is compatible with trimethylsilyl. The organic solvent can be a mixture of toluene, heptane, octane, trichloroethylene or other solvents compatible with hexamethyldisilazane and also miscible with the selected alcohol. Hexamethyldisilazane is then be added to the aforementioned solvent to passivate the surface of the substrate and the structural elements that comprise a micromechanical device. The addition of hexamethyldisilazane to the solvent can result in the generation of ammonia gas which assists in the overall release process. The gas pressure of the ammonia gas also serves to push the structures apart and away from the substrate. Adding hexamethyldisilazane serves to completely displace the organic solvent and prepare the substrate and micromechanical surfaces for drying. Drying can be accomplished by utilizing any of a number of drying techniques such as air drying of the substrate and micromechanical structures in a sterile clean environment or using a convection oven or a hotplate. The process of coating all surfaces with a layer of firmly chemically bound trimethylsilyl groups begins when the hexamethyldisilazane is first added to displace the organic solvent and can continue up until the completion of the drying process wherein the remaining hexamethyldisilazane is removed from the substrate and any mechanical parts. FIG. 2 and FIG. 3 depict a second embodiment of the present invention in which several chemical reactions serve to release micromechanical structures from an associated substrate. Generally, when micromechanical structures are released in hydrofluoric acid and then rinsed in H 2 O, the micromechanical structures stick together when the H 2 O dries due to bonding of oxide or nitride to polysilicon, other oxides, nitrides or other silicon based structures. Micromechanical structural surfaces 90 include an Si 3 N 4 layer 100, an SiO x N y layer 110, a hydroxide layer 102, a SiO x layer 104 and a polysilicon layer 106. H 2 O is removed from micromechanical structural surfaces 90 by drying. Removal of H 2 O modifies the micromechanical structural surfaces 90 to form micromechanical structural surfaces 92, which now include a layer of strong covalent bonds 112. To avoid the formation of a layer of strong covalent bonds 112, the micromechanical structural surfaces 90 should instead be treated with hexamethyldisilazane as shown in FIG. 3. A reaction of hexamethyldisilazane with micromechanical structural surfaces 90 forms layers 96 which now include a non-bonded layer 118. Although the present invention has been shown and described with respect to one embodiment, various changes and other modifications which are obvious to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention.

A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for the oxidation treatment of decaborane gas. More specifically, the invention relates to a boronizing treatment as a boron coating technique. Nuclear fusion reactors have the vacuum vessel boronized on the inner surfaces to provide evaporated boron coatings. For boronization, decaborane (a kind of boron hydride compounds) which is solid and easy to handle at ordinary temperatures is heated to a gaseous phase, which is injected into the vacuum vessel and decomposed by glow discharge. The unreacted or no longer necessary decaborane gas is discharged via an evacuator and carried by nitrogen or some other gas to be passed through a stainless steel tube packed with the granules of an oxidizing agent consisting of potassium permanganate and potassium hydroxide, where the decaborane gas is oxidized to manganese compounds (e.g., manganese oxide) and other stable substances such as potassium borate, water and hydrogen so that the contents of the unreacted decaborane gas and the no longer necessary decaborane gas in the exhaust gas are reduced to below the threshold limit values (TLV) which represent the permissible levels for prolonged exposure. 2. Prior Art To provide boron coatings, diborane and other boron hydride compounds (i.e., gaseous chemical materials) are supplied at constant pressure to vacuum vessels and the like and subjected to either glow discharge or chemical vapor deposition (CVD). The unreacted and no longer necessary gases are discharged from a dedicated evacuator system for treatment by such methods as dilution with an inert gas (e.g., N 2 ), scrubbing with an injected processing agent, combustion and physical adsorption. With the recent advances in the boron coating technology which involves glow discharge or CVD (thin-film formation), the exhaust gases are rarely discharged in the as-supplied gaseous state but more often contain increasing amounts of the particles of highly active chemical species (e.g., excited atoms, molecules and reaction products). Such exhaust gases cannot be completely treated by dilution with an inert gas, scrubbing with an injected processing agent, combustion or physical adsorption and, alternatively, chemical adsorption is employed to remove the unwanted chemical species, thereby providing clean exhaust gases. In the chemical adsorption method, a processing agent mainly composed of an oxidizer is reacted with the gas of a chemical material of interest so that it is oxidized to a stable form. The major chemical materials that can be treated by this method include those which occur in the gaseous phase at ordinary temperatures, such as diborane (B 2 H 6 ), silane (SiH 4 ), phosphine (PH 3 ), arsine (AsH 3 ), hydrogen selenide (H 2 Se), hydrogen tetrafluoride (SiF 4 ), boron trifluoride (BF 3 ), hydrogen fluoride (HF), silicon tetrachloride (SiCl 4 ), hydrogen sulfide (H 2 S), hydrogen chloride (HCl), chlorine (Cl 2 ), boron trichloride (BCl 3 ), dichlorosilane (SiH 2 Cl 2 ) and fluorine (F 2 ). On the other hand, decaborane is solid at ordinary temperatures and there have been available no facilities that permit the use of decaborane either in the solid state or as a gaseous form that has been provided by volatilization under heating. Hence, no practical method has been established that can treat the decaborane gas and in the absence of a suitable agent and an apparatus for treating the exhaust gases, no technology has been available for the safe treatment of the decaborane gas. SUMMARY OF THE INVENTION Decaborane and diborane are both within the class of boron hydrides and one molecule of decaborane is equivalent to five molecules of diborane. Hence, decaborane defies a safe treatment by dilution with an inert gas (e.g., N 2 ), scrubbing with an injected processing agent, combustion or physical adsorption. An object, therefore, of the invention is to treat the decaborane gas, boron reaction products and other highly active particulate materials by chemical adsorption such that they are converted to safe and stable substances, whereby the concentrations of exhaust gases that result from boron coating and other thin-film forming operations by glow discharge and plasma-assisted CVD using decaborane are sufficiently reduced to provide clean emissions. Another object of the invention is to ensure that the process of chemical adsorption can be controlled with the profile of involved reactions being monitored for such purposes as checking the life expectancy of the apparatus for treatment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a stainless steel tube as it is packed with an oxidizing agent and any other substances required to perform oxidation treatment on decaborane gas; FIG. 2 shows how the stainless steel of FIG. 1 looks like if the decaborane gas is subjected to oxidation treatment with the packed oxidizing agent; FIG. 3 is a flowsheet for the process of oxidation treatment of decaborane gas in which a stainless steel tube packed with an oxidizing agent and any other necessary substances is used as a decontamination factor limiter in the boronizing system; and FIG. 4 is a flowsheet of a decontamination factor limiter for use in the oxidation treatment of decaborane gas, which is such that a stainless steel tube packed with an oxidizing agent and any other necessary substances is combined with a break monitor that uses nitrogen as a carrier gas and which monitors (checks) the concentrations of exhaust gases by a diaphragm electrode method. DETAILED DESCRIPTION OF THE INVENTION To attain the stated objects of the present invention, a stainless steel tube is packed with the granules of an oxidizing agent consisting of potassium permanganate (main oxidizer) and potassium hydroxide (reaction accelerator) in such a way as to provide good gas permeability and, in order to check the progress of oxidative reaction between the decaborane gas and the oxidizing agent, a granular monitoring agent mainly composed of copper sulfate is also packed in the stainless steel tube but partitioned from the oxidizing agent by means of a stainless steel screen and the progress of oxidative reaction of the decaborane gas is monitored by watching the changing color of the monitoring agent through an inspection window. To insulate the heat of reaction between the oxidizing agent and the decaborane gas, the greater part of the oxidizing agent is covered with the stainless steel tube so that it cannot be seen through the inspection window. The stainless steel tube is first packed with part of the oxidizing agent, then with the monitoring agent and finally with the remaining part of the oxidizing agent, in such a manner as to enable prediction as to how much time is left for the treatment of the exhaust gases resulting from boronizing to be complete; what is more, the packing order is determined in such a way that the inability of the reaction to be effected in one step is deliberately used to check the residual amount of the oxidizing agent such that the treatment system can be brought to a safe shutdown. The exhaust gases ascend the stainless steel tube as they are progressively reacted with the oxidizing agent to Generate stable compounds such as manganese compounds (e.g., manganese oxide) and potassium borate through the oxidative reaction. Stable gaseous substances (e.g., H 2 ) will also form and pass through the stainless steel tube to be safely discharged into the atmosphere. Thus, according to the method of the present invention for the oxidation treatment of decaborane gas, the oxidizing agent consisting of potassium permanganate and potassium hydroxide are packed into the stainless steel tube in such a way that they will not intermingle with the monitoring copper sulfate and decaborane and other exhaust gases are passed through the layers of the packing materials, whereby the exhaust gases are oxidized to manganese compounds and other stable substances. Stated more specifically, in order to insure safe treatment of the decaborane gas that remains unreacted or that is no longer necessary for boronizing, these gases are directed into a stainless steel tube which is connected to the exit ends of pumps and other evacuating means and which is packed with the oxidizing agent and the monitoring agent both of which are in a granular form to provide good gas permeability and the gases are chemically reacted with the oxidizing agent to be oxidized to stable compounds such as manganese oxide and potassium borate while, at the same time, they are converted to stable gases such as hydrogen gas for discharge into the atmosphere. The oxidizing agent in the stainless steel tube generates heat upon reaction with the decaborane gas and it may be partitioned from the monitoring agent to allow for treatments in the stainless steel tube having high resistance to heat and corrosion. By watching the changing color of the monitoring agent packed in the stainless steel tube at the site where the inspection window is provided, the profile of the treatment of the decaborane gas with the oxidizing agent can be monitored as a function of the progress of oxidation of the ascending decaborane gas, which is a measure of the time where the oxidizing agent is to be replaced by a fresh one. Embodiments of the process of the invention for oxidation treatment of decaborane gas will now be described with specific reference to the accompanying drawings. Conventionally, gases to be removed have been treated by dilution with inert gases (e.g., N 2 ), scrubbing with injected processing agents, combustion and physical adsorption. However, the particles of highly active chemical species such as decaborane gas cannot be effectively treated by these methods to produce clean exhaust gases. According to the invention, such particles of highly active materials are treated by chemical adsorption (oxidation) to produce clean exhaust gases. FIG. 1 is a schematic representation of a stainless steel tube as it is packed with an oxidizing agent and any other substances required to perform oxidation treatment on decaborane gas. As shown, the stainless steel tube has a gas reservoir in the bottom and a closing flange on the top. Packed in between are part of the oxidizing agent, a monitoring agent, the remainder of the oxidizing agent and a mass of glass wool. A stainless steel screen is provided in three positions, the first for separating the gas reservoir from part of the oxidizing agent, the second for isolating said part of the oxidizing agent from the monitoring agent, and the third for isolating the monitoring agent from the remainder of the oxidizing agent. The mass of glass wool is provided for ensuring against runaway of the oxidizing agent. In the case shown in FIG. 1, decaborane gas and other emissions from processes such as boronizing enter the gas reservoir through an inlet at the bottom of the stainless steel tube and ascends (the decaborane gas has a specific gravity less than unity) the tube by sequentially passing through the first stainless steel screen, the first part of the oxidizing agent, the second stainless steel screen, the monitoring agent, the third stainless steel screen, the second part of the oxidizing agent and the glass wool and thereafter leaves the stainless steel tube via an exhaust gas outlet. The closing flange on the top of the stainless steel tube permits a fresh oxidizing agent to be loaded in the tube from above while a spent oxidizing agent can be disposed of as a waste. Additionally, in order to ensure that the amount of the oxidizing agent is variable with the volume of the decaborane gas to be treated, two or more units of the stainless steel tube can be interconnected by means of coupling flanges. FIG. 2 shows how the stainless steel tube looks like if decaborane gas is subjected to oxidation treatment with the packed oxidizing agent. The decaborane gas entering the stainless steel tube packed with the oxidizing agent undergoes an oxidative reaction with the latter to be converted not only to solid and stable substances such as manganese compounds but also to gaseous and stable substances such as hydrogen. The gaseous substances produced are passed through the spaces between individual granules of the oxidizing agent to be discharged from the stainless steel tube via the outlet on the top. The oxidative reaction progresses from bottom to top and if the oxidizing agent is no longer capable of treating the supplied decaborane gas, its oxidizing ability is saturated and manganese compounds and other stable substances will simply build up. If the ability of the oxidizing agent is saturated, the monitoring agent reacts with the decaborane gas and the resulting change in color will provide a visual signal for the time at which the oxidizing agent is to be replaced. The progress of the oxidative reaction can be monitored by looking through the inspection window. Even if the ability of the oxidizing agent drops, the boronizing treatment under progress cannot be brought to an immediate stop; alternatively, the exhaust decaborane gas is treated with the oxidizing agent lying above the monitoring agent until the treatment system is brought to safe shutdown. The decaborane gas (B 10 H 14 ) reacts with the oxidizing agent (consisting of potassium permanganate KMnO 4 and potassium hydroxide KOH) according to the following schemes: B.sub.10 H.sub.14 +6K.sub.2 MnO.sub.4 +10K.sub.3 BO.sub.3 +6H.sub.2 O+19H.sub.2 1 2B.sub.10 H.sub.14 +30K.sub.2 MnO.sub.4 +H.sub.2 →15Mn.sub.2 O.sub.3 +2OK.sub.3 BO.sub.3 +15H.sub.2 O 2 Thus, the reaction between the decaborane gas and the oxidizing agent proceeds in two different ways, yielding different intermediates. The oxidized decaborane gas is eventually converted to stable substances, i.e., manganese oxide (Mn 2 O 3 ), potassium borate (K 3 BO 3 ), water (H 2 O) and hydrogen (H 2 ), in accordance with the following scheme: 7B.sub.10 H.sub.14 +3OKMnO.sub.4 +18OKOH→15Mn.sub.2 O.sub.3 +7OK.sub.3 BO.sub.3 +45H.sub.2 O+94H.sub.2 3 The copper sulfate (CuSO 4 ) used as the monitoring agent typically assumes a pale blue color and turns to brown upon reaction with the decaborane gas. FIG. 3 is a flowsheet for the method of the invention for the oxidation treatment of decaborane gas in which the stainless steel tube packed with an oxidizing agent and any other necessary substances is used as a decontamination factor limiter in the boronizing system. As shown, the boronizing system consists of a decaborane gas feed line and a waste decaborane gas discharge line; the feed line comprises a materials container MC, mass flow controllers FC, gate valves GV, pneumatic valves V, a turbomolecular pump TMP, a rotary pump RP, a first decontamination factor limiter DFL and other components, whereas the discharge line comprises gate valves, pneumatic valves, a turbomolecular pump, a rotary pump, a second decontamination factor limiter and other components. Shown by RGA is a quadrupole mass analyzer used as a residual gas analyzer and G 1 -G 4 are gas leakage detectors. The areas enclosed with dashed lines represent the regions to be heated. Boronizing is a process in which helium and decaborane gases are supplied from the decaborane gas feed line to be injected into the vacuum vessels equipped with glow discharge electrodes, where it is decomposed by glow discharge to provide a boron coat. As a result, the unreacted decaborane gas is rejected from the dedicated discharge line whereas the unwanted decaborane gas which has occurred is due to the stop of feed injection into the vacuum vessel rejected from the feed line. Both gases are harmful and discharged into the atmosphere after being treated to a safe form by the associated decontamination factor limiters. FIG. 4 is a flowsheet of a decontamination factor limiter for use in the oxidation treatment of decaborane gas according to the present invention, which is such that a stainless steel tube packed with an oxidizing agent and any other necessary substances is combined with a break monitor that uses nitrogen gas as a carrier gas and which monitors (checks) the concentrations of exhaust gases by a diaphragm electrode method. The symbols in FIG. 4 denote the following: V-1, a first inlet valve for the exhaust gas; V-2, a second inlet valve for the exhaust gas; V-3, the outlet valve for the treated gas; P-1, the main valve on a pressure gage; P1, the pressure gage; N-1, a first inlet valve for nitrogen gas; N-2, a second inlet valve for nitrogen gas; CK-1, a check valve; PR-1, a first pressure release valve; FM-1, a flow meter; PR-2, a second pressure release valve; NV-1, a nitrogen flow control valve; S-1, an inlet valve to the break monitor; S-2, an outlet valve from the break monitor; and GF-1, a gas filter. The decontamination factor limiter pumps a specified volume or pressure of nitrogen gas into both the break monitor and the stainless steel tube packed with the oxidizing agent and the decaborane gas entering the stainless steel tube via the exhaust gas inlet reacts with the oxidizing agent and the oxidized gaseous emissions are drawn into the break monitor together with nitrogen gas and compared with the pumped nitrogen gas to detect the concentration of the decaborane gas. If the detected value is abnormal (greater than the TLV), the break monitor delivers an alarm signal. After the comparison, the gaseous emissions will be discharged from the exhaust gas outlet. When not in operation and during the storage of the materials to be reacted, the system shown in FIG. 4 can be sealed by closing the valves at the inlet and outlet for the exhaust gas. As described above in detail, the method of the present invention for the oxidation treatment of decaborane gas ensures that the decaborane gas resulting from a boron coating operation using decaborane is passed through a stainless steel tube packed with an oxidizing agent consisting of potassium permanganate and potassium hydroxide, whereby the decaborane gas is chemically reacted with the oxidizing agent such that it is oxidized to safe solid or gaseous substances. If an inspection window is provided in the stainless steel tube, the progress of the oxidative reaction can be monitored by looking through the window and this enables the operator to know the right time at which the oxidizing agent should be replaced. What is more, the solid and gaseous substances resulting from the oxidation treatment are stable enough to allow for safe disposal as wastes. The applicability of the invention is by no means limited to decaborane gas and it would be applicable to other boron hydrides in a gaseous state.

The unwanted or unreacted decaborane gas that results from a boronizing operation using decaborane which is solid at ordinary temperatures but which is heated to a gaseous phase for injection into a vacuum vessel is passed through a metal tube packed with the granules of an alkaline oxidizing agent consisting of potassium permanganate and potassium hydroxide, whereby the decaborane gas is oxidized to solid and gaseous stable substances including manganese compounds and hydrogen. This provides an effective method for removing boron from the boron-containing exhaust gases that result from the coating of the inner surfaces of vacuum vessels in nuclear fusion reactors with an evaporated boron film.

This application is a U.S. national phase application under 35 U.S.C. of §371 of International Application No. PCT/EP2013/066354, filed Aug. 5, 2013, which claims priority to DE10 2012 107 199.3, filed on Aug. 6, 2012; the disclosures of which are all hereby incorporated by reference herein. FIELD OF THE INVENTION The invention relates to a method for producing carbon-coated metal oxide particles and also to their use as electrode material for lithium ion batteries. BACKGROUND OF THE INVENTION Lithium ion batteries currently constitute the leading technology within the field of rechargeable batteries, and they dominate the battery market for portable electronics. Applications for lithium ion batteries in electrical vehicles or in storage technologies for wind or solar energy, for example, nevertheless necessitate the development of rechargeable battery technologies and active materials having significantly higher specific energies and capacities than have hitherto been available commercially or at all. There is therefore need not only for an improvement of existing electrode materials, but also for development of new materials with suitability as the active material for lithium ion batteries. New electrode materials follow in principle two different mechanisms of lithium acceptance, either the reversible formation of an alloy with lithium, as in the case of silicon, tin, antimony, aluminum, or zinc, or the so-called conversion reactions, such as for cobalt oxide, nickel oxide, iron oxide, or copper oxide, for example. Alloy-forming materials, however, suffer severe changes in volume as a result of lithium acceptance and release, thereby destroying the material and causing a loss of electronic contact between active material and current collector. Nevertheless, materials which form reversibly alloys with lithium are currently viewed as the more promising for short-term industrial applications. In 2005, for example, Sony announced the marketing of the Nexelion™ battery, which is based on an Sn—Co—C composite as anode material. Research is presently focused on silicon-based or tin-based electrode materials, whereas zinc, as a potential replacement for the graphite normally used commercially as anode material, is finding little attention, despite promising results achieved with ZnO—Fe 2 O 3 —, ZnO 1-x S x —, and Al 2 O 3 -doped thin-film ZnO structures. However, the electrodes in question have been produced by means of complex methods such as magnetron sputtering, and only thin layers of the active material are characterized. These layers are poorly suited as active material for lithium ion cells with high energy density. Apart from the less-suitable methods of electrode production for industrial applications, furthermore, the materials exhibit an inadequate specific capacity. Moreover, the irreversible formation of Li 2 O in the first cycle leads to a loss of capacity. Specification U.S. Pat. No. 3,330,697 further describes the so-called Pecchini process for producing perowskitic compounds. Disadvantages of this, however, include firstly the volume expansion that occurs and secondly the formation of nitrogen-containing gases in the course of this combustion-based synthesis process starting from metal nitrates. SUMMARY OF THE INVENTION It was an object of the present invention, accordingly, to provide a method for producing a ZnO-based electrode material that is suitable for use as electrode material with enhanced specific capacity and cycling stability in a lithium ion battery. This object is achieved by a method for producing carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14, comprising the following steps: a) mixing stoichiometric amounts of a Zn salt and of a transition metal salt with a sugar in a solvent; b) drying the mixture from step a); c) calcining the dried mixture from step b); d) mixing the M x Zn 1-x O particles obtained from step c) with a sugar in a solvent; e) carbonizing the mixture from step d). The method of the invention provides a simple and cost-effective synthesis opportunity for carbon-coated, transition metal-doped zinc oxide particles having a size in the nanometer range. The steps of the method can be performed under mild conditions and without costly and inconvenient apparatus-based operations. This further permits an industrial implementation that is easily realizable. Especially in comparison to the known wet-chemical Pecchini process for producing perowskitic materials, which uses nitrate solutions in a stoichiometric mixture, the expansion in volume can be reduced by the sole use of sugar as growth inhibitor for the particles. In addition it is possible to avoid the disadvantage of the formation of nitrogen-containing gases in combustion-based synthesis processes starting from metal nitrates. It has further been found, surprisingly, that the use of carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 as electrode material, more particularly for lithium-based energy storage devices, can provide, these being distinguished by a significantly increased specific capacity and superior cycling stability relative to the use of zinc oxide. The term “calcining” refers in the sense of the present invention, generally, to a thermal treatment step in the presence of oxygen, such as in the presence of air, for example; in other words, the heating of a material with the goal of its decomposition. The material to be decomposed is the sugar in accordance with the invention. The term “carbonizing” refers in the sense of the present invention to a thermal treatment step for converting a carbon source, more particularly a sugar as carbon-containing starting material, into a carbon-containing residue in the absence of oxygen or hydrogen. The method is more particularly a method for producing an electrode material, more particularly for lithium-based energy storage devices, comprising carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14. The term “particle” is used in the sense of the present invention synonymous to “particle”. The term “M x Zn 1-x O particles” refers in the sense of the present invention to zinc oxide compounds doped with the transition metal M. The ratio of transition metal M to zinc here may be in the range from x≧0.02 to ≦0.14:1-x, preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x. The term “stoichiometric amount” refers in the sense of the present invention to the amount of the zinc salt and transition metal salt required in each case, in accordance with the ratio of the equivalent weights, for producing the respective M x Zn 1-x oxide. To produce M 0.1 Zn 0.9 O, accordingly, 0.9 mol of zinc(II) gluconate and 0.1 mol of iron gluconate were used. The salts of zinc and transition metal are preferably water-soluble organic salts. Organic salts have the advantage that the organic counterion can be removed from the reactant mixture at the calcining stage, more particularly in the form of carbon dioxide. The term “water-soluble” in the sense of the present invention means that the salt can be dissolved to an extent of at least 0.5 mol/l in water. Preference is given to readily soluble salts having a solubility of greater than 1 mol/l. In preferred embodiments of the method, the salts of zinc and transition metal are an organic salt selected from the group comprising gluconates, citrates, acetates, formates, butyrates, lactates, glycolates, tartrates, propionates and/or succinates. Preference is given to gluconates, citrates, and acetates, more particularly gluconates. Zinc gluconates and transition metal gluconates are readily soluble in water. The sugar is preferably a mono-, di- or polysaccharide, more particularly selected from the group comprising glucose, fructose, sucrose, lactose, starch, cellulose and/or derivates thereof. Especially preferred is sucrose. Sugars dissolve well in water. The water-soluble di- or monosaccharides such as sucrose and lactose and also glucose and fructose are therefore preferred. The solvent is preferably water. With preference no citric acid is added to the sugar solution. This has the advantage that there is a lower expansion in volume in the course of calcining. It has further been found that when water is used as solvent, without addition of citric acid, smaller particles have been obtainable that with addition of citric acid. It has also been possible to record a lower level of agglomeration of the particles. For example, first of all solutions of the sugar and of the separately or jointly dissolved salts in the solvent can be prepared, and then the solution of the metal salts can be added to the sugar solution. It is preferred for stoichiometric amounts of the zinc salt and of the transition metal salt to be dissolved jointly. The sugar is preferably dissolved in small amounts of water, to give a viscous solution. The ratio of the concentration of the metal ions and of the sugar is preferably in the range from 1:1 to 1:50, preferably in the range from 1:2 to 1:20, more preferably in the range from 1:4 to 1:10, more particularly 1:6. A ratio of 1:6 has emerged as being an especially suitable ratio for achieving particle growth in the desired size range and preventing oxidation of the transition metals. The mixing may take place at ambient or room temperature. The drying of the mixture prior to calcining takes place preferably at a temperature in the range from ≧70° C. to ≦300° C., more preferably in the range from 120° C. to ≦300° C., very preferably in the range from ≧150° C. to ≦300° C. Drying may be performed in the air. Drying before calcining has the advantage that there is no further expansion in volume during the calcining of the dried mixture. Prior to drying, the solvent can first of all be evaporated, at 150° C. to 180° C., for example. By this means the sugar can be dehydrated. As a result of the calcining, the sugar and also the organic anions of the metal salts are removed from the mixture, and zinc oxide particles doped with the transition metal of the formula M x Zn 1-x O, are formed. In preferred embodiments, the calcining is performed at a temperature in the range from ≧300° C. to ≦500° C., preferably in the range from ≧350° C. to ≦450° C., more preferably in the range from ≧400° C. to ≦450° C. These temperatures are able to ensure that reduction of the metal cations to the pure metal can be avoided. Advantageously in this way it is possible to obtain transition metal-doped zinc oxide particles having a size in the nanometer range. The particles preferably have a spherical or ball shape. More particularly, the transition metal-doped zinc oxide particles can have an average diameter in the range from ≧10 nm to ≦200 nm, preferably in the range from ≧15 nm to ≦50 nm, more preferably in the range from ≧20 nm to ≦30 nm. The term “average diameter” refers to the average value of all diameters or arithmetically averaged diameters, relative to all particles. Particles having a size in the nanometer range are able to provide high specific surface area. This permits a large contact area of the particles with an electrolyte, and hence a large number of possible reaction sites with the Li + ions present in the electrolyte. The calcined particles may optionally be comminuted or pulverized, in a mortar, for example. Without being tied to any particular theory, it is assumed that the sugar as growth inhibitor brings about the formation of transition metal-doped zinc oxide having a particle size in the nanometer range. The transition metal-doped zinc oxide particles obtained from the calcining can be used as electrode material. It is nevertheless preferable for the particles to be provided with a carbon coating in the ongoing method. A carbon coating leads advantageously to a significant enhancement of the electronic conductivity of the material. For this purpose, the M x Zn 1-x O particles can again be mixed with a sugar in a solvent. The sugar is preferably a mono-, di-, or polysaccharide, more particularly selected from the group comprising glucose, fructose, sucrose, lactose, starch, cellulose and/or derivatives thereof. Especially preferred is sucrose. It is preferable to use the same sugar for calcining and carbonizing. The solvent is preferably water. For example, the sugar can be dissolved in the solvent and then the transition metal-doped zinc oxide particles can be added and dispersed with the sugar dispersed in the solvent. The term “dispersing” means the mixing of at least two substances which undergo little or no dissolution in one another or chemical bonding with one another, an example being the distribution of the particles as a disperse phase in a sugar solution as a continuous phase. A distribution as uniform as possible of the particles in an aqueous sugar solution is preferred, in order to obtain as uniform as possible wetting of the particles with the sugar. The dispersing may be performed, for example, in a ball mill, over a period of 1 to 2 hours, as for example for 1.5 hours. The sugar is preferably dissolved in small amounts of water, to give a viscous solution. Sugar and transition metal-doped zinc oxide particles are preferably mixed in a ratio by mass in the range from 1:50 to 10:1, more preferably in the range from 1:10 to 2:1, very preferably in the range from 1:2 to 1:1, more particularly at 3:4. The mixture is preferably dried before the carbonizing. By this means the sugar can be dehydrated. Drying may take place at a temperature in the range from ≧18° C. to ≦100° C., preferably in the range from ≧20° C. to ≦80° C., more preferably in the range from ≧23° C. to ≦50° C. Drying may be performed in particular at ambient temperature, as for example in the range from ≧18° C. to ≦23° C. The drying may be carried out in the air. The dried mixture may optionally then be comminuted or pulverized in a mortar, for example. By this means, sugar-wetted particles which have undergone sticking or clumping as a result of the drying can be parted from one another again. Thereafter the mixture is carbonized. The carbonizing forms a carbon coating on the transition metal-doped zinc oxide particles. The carbonizing is preferably performed under an inert gas atmosphere, of argon, nitrogen, or mixtures thereof, for example. By this means it is possible to prevent unwanted secondary reactions such as oxidation of the carbon coating. In preferred embodiments the carbonizing is performed at a temperature in the range from ≧350° C. to ≦700° C., preferably in the range from ≧400° C. to ≦600° C., more preferably in the range from ≧450° C. to ≦550° C. Advantageously, these conditions are mild, and so there is no further reduction of the doped zinc oxides. The temperatures and conditions are more particularly selected such that both zinc and the transition metal are not reduced to the pure metals. The carbonizing may be performed, for example, for a period in the range from ≧1 h to ≦24 h, preferably in the range from ≧2 h to ≦12 h, preferably in the range from ≧3 h to ≦6 h. After the carbonizing, the carbon-coated particles obtained may be comminuted or pulverized, by mortaring, for example. The method using sugar provides, in particular, a mild method for producing carbon-coated M x Zn 1-x O particles. The method further has the advantage of releasing only CO 2 , which is nontoxic. With sugar as carbon source and water as solvent, favorable starting materials can be used. Moreover, the method does not require any costly and inconvenient apparatus, meaning that industrial application can be realized easily and quickly. The carbon-coated M x Zn 1-x O particles can be used in particular as electrode material for the production of anodes for lithium ion batteries. The carbon coating applied by the carbonizing results advantageously in a significant increase in the electronic conductivity of the material. This is a great advantage particularly for subsequent use as electrode material in lithium ion batteries, since it enables very good to good charge states of the active material to be achieved even in the case of very high applied current densities. Furthermore, the carbon coating is able to act as a buffer for the volume expansion and volume reduction which occur in the course of lithiation and dilithiation. This raises the cycling stability of the electrode and results in a higher achievable cycle number at virtually constant capacity. Furthermore, the carbon coating not only contributes to a significant improvement in the electronic conductivity, but also is electrochemically active itself within the potential range utilized, and is able to store lithium ions. The carbon cladding, moreover, prevents physical contact of the nanoparticles and therefore actively counteracts particle agglomeration in the course of electrode production and cycling. A particular advantage is that sucrose can be converted to amorphous carbon by the carbonizing procedure. Amorphous carbon not only possesses a high electronic conductivity, but at the same time is permeable to the electrolyte and to the lithium ions. Furthermore, amorphous carbon is especially suitable for cushioning an expansion in volume of the particles during the charging and discharge of the electrodes. A further subject of the invention relates to carbon-coated particles, obtainable by the method of the invention, of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14. As active material, the carbon-coated M x Zn 1-x O particles obtainable with the method of the invention are notable for superior cycling stability in the electrodes produced from them, and significantly increased specific capacity and significantly reduced loss of capacity in the first cycle, relative to the use of zinc oxide. Moreover, electrodes based on the use of M x Zn 1-x O particles, and more particularly those based on the use of carbon-coated M x Zn 1-x O particles, as active material, exhibit a superior specific capacity for increasing applied current densities, which are higher by a factor of around three than those achievable when using ZnO. In comparison to graphite as well, which is presently the most widely used anode material, specific capacities which are more than twice as high can be achieved for a wide bandwidth of applied current densities. In the M x Zn 1-x O particles, x is between 0.02 and 0.14. Higher proportions of transition metal can lead to a phase transition of the doped zinc oxide particles in the course of calcining. The ratio of transition metal M to zinc may be preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The transition metal M is preferably iron or cobalt. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x. Particularly preferred particles are carbon-coated Co 0.1 Zn 0.9 O and Fe 0.1 Zn 0.9 O particles. Further particularly preferred particles are carbon-coated Co 0.12 Zn 0.88 O and Fe 0.12 Zn 0.88 O particles. It has been found, for example, that in the range 0.02≦x≦0.12, the iron fraction was advantageous for the achievable specific capacity and discharge rate. Overall, a transition metal fraction with these ranges, more particularly of 0.02≦x≦0.12 is advantageous for an electrode produced from this material. The fraction of carbon, based on the total weight of the carbon-coated M x Zn 1-x O particles, is preferably in the range from 0.5 wt % to ≦70 wt %, preferably in the range from 2 wt % to ≦30 wt %, more preferably in the range from ≧5 wt % to ≦20 wt %. It has been found that in a range from ≧5 wt % to ≦20 wt % of carbon, with increasing carbon content, the density and crystallinity and also the specific surface area showed an advantageous combination, especially in the range from ≧12 wt % to ≦20 wt % of carbon. The carbon-coated particles preferably have a BET surface area in the range from ≧1 m 2 /g to ≦200 m 2 /g, more preferably in the range from ≧50 m 2 /g to ≦150 m 2 /g, very preferably in the range from ≧70 m 2 /g to ≦130 m 2 /g. Advantageously there is no substantial increase in the average diameter of the transition metal-doped zinc oxide particles as a result of the carbonizing procedure. Hence the carbon-coated, transition metal-doped zinc oxide particles can have an average diameter in the range from ≧15 nm to ≦250 nm, preferably in the range from ≧20 nm to ≦80 nm, more preferably in the range from ≧25 nm to ≦50 nm. The invention further relates to the use of M x Zn 1-x O particles, more particularly of carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14, as electrode material for electrochemical energy storage devices, more particularly alkali metal ion batteries or supercapacitors. A further subject of the invention relates to an electrode material for electrochemical energy storage devices, more particularly alkali metal ion batteries or supercapacitors, comprising M x Zn 1-x O particles, more particularly carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14. A further subject of the invention relates to an electrode comprising M x Zn 1-x O particles, more particularly carbon-coated particles of M x Zn 1-3 O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14. Electrodes just comprising particles of M x Zn 1-3 O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 are notable for an increased specific capacity, improved cycling stability and a reduced irreversible capacity loss at the start, relative to the use of zinc oxide. More particularly, electrodes comprising carbon-coated M x Zn 1-x O particles are notable for a further significant increase in the specific capacity and in the cycling stability, and also for reduced irreversible capacity loss at the start. In the M x Zn 1-x O particles, x is between 0.02 and 0.14. The ratio of transition metal M to zinc may be preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The transition metal M is preferably iron or cobalt. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x. Particularly preferred particles are carbon-coated Co 0.1 Zn 0.9 O and Fe 0.1 Zn 0.9 O particles. The fraction of carbon, based on the total weight of the carbon-coated M x Zn 1-x O particles, is preferably in the range from 0.5 wt % to ≦70 wt %, preferably in the range from 2 wt % to ≦30 wt %, more preferably in the range from ≧5 wt % to ≦20 wt %. The carbon-coated particles preferably have a BET surface area in the range from ≧1 m 2 /g to ≦200 m 2 /g, more preferably in the range from ≧50 m 2 /g to ≦150 m 2 /g, very preferably in the range from ≧70 m 2 /g to ≦130 m 2 /g. Additionally the carbon-coated, transition metal-doped zinc oxide particles can have an average diameter in the range from ≧15 nm to ≦250 nm, preferably in the range from ≧20 nm to ≦80 nm, more preferably in the range from ≧25 nm to ≦50 nm. For the description of the particles, reference is made to the description above. These particles form the material of the electrode which is commonly identified as active material and which carries out, for example, reversible acceptance and release of lithium. This material may further comprise binders and additives. Correspondingly, the active material of an electrode may be formed from the particles or consist substantially thereof. The active material is usually applied to a metal foil, such as a copper foil or aluminum foil, for example, or to a carbon-based current collector foil which acts as a current collector. Since the active material accounts for the substantial part of the electrode, the electrode may in particular also be formed of or based on M x Zn 1-x O particles, more particularly carbon-coated M x Zn 1-x O particles. An electrode of this kind is commonly referred to as a composite electrode. In preferred embodiments the electrode is a composite electrode comprising M x Zn 1-x O particles, more particularly carbon-coated M x Zn 1-x O particles, binder, and optionally conductive carbon. In the case of carbon-coated M x Zn 1-x O particles there is no need to use additional carbon for producing an electrode. Advantageously, the carbon network of the carbon coating is able to provide sufficient electrical conductivity on the part of the electrode. Provision may be made, however, to add further carbon for producing an electrode. This allows the conductivity of the electrode to be increased further. Carbon may also be added prior to carbonizing, and may for example be dispersed in the sugar solution together with the M x Zn 1-x O particles themselves. Preference is given to adding carbon only during the production of an electrode. With preference, conductive carbon can be added at a weight ratio of particles to carbon in the range from ≧1:10 to ≦40:1, preferably in the range from ≧7:3 to ≦20:1, and especially particularly at a weight ratio in the range from ≧3:1 to ≦4:1. Examples of preferred carbon-containing materials are carbon black, synthetic or natural graphite, graphene, carbon nanoparticles, fullerenes, or mixtures thereof. One carbon black which can be used is available, for example, under the trade name Ketjenblack®. A carbon black which can be used with preference is available, for example, under the trade name Super P® and Super P Li®. The carbon-containing material may have an average particle size in the range from 1 nm to 500 μm, preferably from 5 nm to 1 μm, more preferably in the range from 10 nm to 60 nm. The average diameter of the carbon particles may 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, very preferably in the range from 10 nm to 60 nm. The fraction of uncoated or carbon-coated M x Zn 1-x O particles, based on the total weight of particles, binder, and conductive carbon, is preferably in the range from ≧10 wt % to ≦98 wt %, more preferably in the range from 50 wt % to ≦95 wt %, very preferably in the range from ≧75 wt % to ≦85 wt %. The fraction of added conductive carbon based on the total weight of the composite electrode made up of uncoated or carbon-coated M x Zn 1-x O particles, binder, and conductive carbon, is preferably in the range from ≧0 wt % to ≦90 wt %, more preferably in the range from 2 wt % to ≦50 wt %, very preferably in the range from ≧5 wt % to ≦20 wt %. The composite electrode may further comprise binders. Suitable binders are, for example, poly(vinylidene difluoride-hexafluoropropylene) (PVDF-HFP) copolymer, polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), styrene-butadiene rubber (SBR), carboxymethylcellulose (CMC), as for example sodium carboxymethylcellulose (Na-CMC), or polytetrafluorethylene (PTFE) and cellulose, more particularly natural cellulose, and also suitable combinations of different binders. A preferred binder is carboxymethylcellulose (CMC), such as sodium carboxymethylcellulose (Na-CMC). The composite electrode preferably comprises carboxymethylcellulose as binder. Carboxymethylcellulose is more eco-friendly and more cost-effective by comparison with binders used in customary commercial batteries. In particular, carboxymethylcellulose is water-soluble. Hence carboxymethylcellulose permits the use of water as a dispersion medium for electrode production. Furthermore, in contrast to the use of fluorene-containing binders, carboxymethylcellulose allows easy recycling of the electrode materials at the end of the life cycle of the batteries, by pyrolysis. The composite electrode, based on the total weight of uncoated or carbon-coated M x Zn 1-x O particles, binder, and optionally conductive carbon, preferably has a binder fraction in the range from ≧1 wt % to ≦50 wt %, more preferably in the range from ≧2 wt % to ≦15 wt %, more preferably in the range from ≧3 wt % to ≦10 wt %. For example, the fraction of binder may be 5 wt %, based on the total weight. The dry weight of a mixture of uncoated or carbon-coated M x Zn 1-x O particles, binder, and conductive carbon may for example have 75 wt % of carbon-coated M x Zn 1-x O particles, 20 wt % of conductive carbon black, and 5 wt % of binder, carboxymethylcellulose for example, based on the total weight of the mixture. The production of an electrode may comprise the steps of mixing the uncoated or carbon-coated M x Zn 1-x O particles with carbon black, and mixing the solids mixture with a binder in solution in solvent—for example, carboxymethylcellulose in solution in water—and applying the mixture to a conductive substrate, and drying the resulting electrodes. The mixture may be applied, for example, with a wet film thickness in the range from ≧20 μm to ≦2 mm, preferably in the range from ≧90 μm to ≦500 μm, more preferably in the range from ≧100 μm to ≦200 μm. The surface coverage of the electrode may be in the range from ≧0.2 mg cm −2 to ≦30 mg cm −2 , preferably in the range from ≧1 mg cm −2 to ≦150 mg cm −2 , more preferably in the range from ≧2 mg cm −2 to ≦10 mg cm −2 . A further subject of the invention relates to an electrochemical energy storage device, more particularly an alkali metal ion battery or a supercapacitor, preferably primary lithium batteries, primary lithium ion batteries, secondary lithium ion batteries, primary lithium polymer batteries, or lithium ion capacitors, comprising an electrode of the invention. The term “electrochemical energy storage device” encompasses single-use batteries (primary storage cells) and rechargeables (secondary storage cells). In the general terminology, however, rechargeables are frequently designated likewise using the term “battery”, which is widely used as a generic term. For example, the term “lithium ion battery” is used synonymously with “rechargeable lithium ion battery”. Lithium-based energy storage devices are preferably selected from the group comprising primary lithium batteries, primary lithium ion batteries, secondary lithium ion batteries, primary lithium polymer batteries, or lithium ion capacitors. Preference is given to primary and secondary lithium ion batteries. Furthermore, however, the transition metal-doped zinc oxide particles can also be used independently of electrochemical energy storage devices. A further subject of the invention relates to the use of particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 as color pigment for ceramic materials or applications. In particular, Fe x Zn 1-x O and Co x Zn 1-x O particles are highly suitable for use as color pigments, on account of their intense yellow-orange and/or green color. Examples and figures which serve for illustrating the present invention are indicated hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS The figures, in this context, show the following: FIG. 1 shows X-ray diffractograms. FIG. 1 a ) shows the X-ray diffractogram of the Fe 0.1 Zn 0.9 O particles and also the signals of the JCPDS files of Co 0.15 Zn 0.85 O; FIG. 1 b ) shows that of the carbon-coated Fe 0.1 Zn 0.9 O particles, and also, likewise, the signals of the JCPDS file for Co 0.15 Zn 0.85 O. FIG. 2 shows scanning electron micrographs (200 000× magnification) of the Fe 0.1 Zn 0.9 O particles obtained after calcining, in FIG. 2 a ) and also, in FIG. 2 b ), shows the carbon-coated Fe 0.1 Zn 0.9 O particles obtained after carbonizing with sugar. FIG. 3 shows in FIG. 3 a ) the X-ray diffractogram of the Co 0.1 Zn 0.9 O particles and also the signals of the JCPDS file of Co 0.15 Zn 0.85 O, and also, in FIG. 3 b ), shows a scanning electron micrograph (200 000× magnification) of the Co 0.1 Zn 0.9 O particles. FIG. 4 shows in FIG. 4 a ) the X-ray diffractogram of the ZnO particles and also the signals of the JCPDS file of ZnO, and also, in FIG. 4 b ), shows a scanning electron micrograph (200 000× magnification) of the ZnO particles. FIG. 5 shows the capacity characteristics of a composite electrode comprising zinc(II) oxide particles over 100 cycles with increasing charge and discharge rates. FIG. 6 shows the capacity characteristics of a composite electrode comprising Fe 0.1 Zn 0.9 O particles over 100 cycles with increasing charge and discharge rates. FIG. 7 shows the capacity characteristics of a composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles over 100 cycles with increasing charge and discharge rates. FIG. 8 shows the capacity characteristics of a composite electrode comprising Co 0.1 Zn 0.9 O particles over 21 cycles with increasing charge and discharge rates. FIG. 9 shows the voltage profile of a composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles against metallic sodium. FIG. 10 shows the capacity characteristics of composite electrodes comprising carbon-coated Fe x Zn 1-x O particles over 70 cycles with increasing charge and discharge rates. In this figure, FIG. 10 a ) shows the capacity characteristics of Fe 0.12 Zn 0.88 O particles, FIG. 10 b ) that of Fe 0.1 Zn 0.9 O particles, FIG. 10 c ) that of Fe 0.08 Zn 0.92 O particles and FIG. 10 d ) that of Fe 0.06 Zn 0.94 O particles. DETAILED DESCRIPTION OF THE INVENTION Example 1 Production of Carbon-Coated Fe 0.1 Zn 0.9 O Particles a) Production of Fe 0.1 Zn 0.9 O Particles Stoichiometric amounts of 8.204 g of zinc(II) gluconate hydrate (ABCR, 97% purity) and 0.965 g of iron gluconate dihydrate (Sigma-Aldrich, 98% purity) were dissolved in 100 ml of deionized water (Millipore) to give a total metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+%) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The solid obtained was then dried at 300° C. for 10-20 minutes. The dried solid was then roughly comminuted by hand, and heated in an air atmosphere at 450° C. for 3 hours. During this time, the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours. After the calcining, the sample obtained was briefly mortared by hand, giving a very fine powder after just about 30 seconds. The morphology of the Fe 0.1 Zn 0.9 O particles obtained after calcining was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 1 a ) shows the X-ray diffractogram of the particles obtained, and also the signals of the JCPDS file (Joint Committee of Powder Diffraction Standards) for Co 0.15 Zn 0.85 O with P63mc space group (JCPDS 01-072-8025). As can be seen from FIG. 1 a ), the signals observed for the calcined Fe 0.1 Zn 0.9 O particles were unambiguously assignable to the signals of Co 0.15 Zn 0.85 O, which has a virtually identical structure and was therefore utilized as reference, since there is no corresponding reference available for iron-doped zinc oxide. b) Carbon Coating of the Fe 0.1 Zn 0.9 O Particles 0.75 g of sucrose (Acros Organics, 99+%) was dissolved with stirring in 3.5 ml of deionized water. Then 1 g of the Fe 0.1 Zn 0.9 O particles from step a) was added and the mixture was homogenized for 1.5 hours in a ball mill (Vario-Planetary Mill Pulverisette 4, Fritsch) at 800 rpm. The resulting mixture was dried in the air at 80° C. overnight and then heated in an argon atmosphere at 500° C. for 4 hours with a heating rate of about 3° C. min −1 . The solid obtained was then mortared by hand. The morphology of the carbon-coated Fe 0.1 Zn 0.9 O particles (Fe 0.1 Zn 0.9 O—C) was determined again by X-ray powder diffractometry. FIG. 1 b ) shows the X-ray diffractogram of the carbon-coated particles obtained, and also the signals of the JCPDS file for Co 0.15 Zn 0.85 O. As can be seen from FIG. 1 b ), the signals observed for the carbon-coated particles again corresponded unambiguously to the signals of Co 0.15 Zn 0.85 O, whose crystal structure is virtually identical to that of Fe 0.1 Zn 0.9 O. This shows that the carbonizing with sucrose has not adversely affected the phase purity of the Fe 0.1 Zn 0.9 O particles. The absence of further reflections such as for graphitic carbon shows additionally that a coating of amorphous carbon has been formed. The presence of carbon was confirmed by means of CHN elemental analysis (CHN-O-Rapid, Heraeus). The fraction of carbon was determined by thermogravimetric analysis (TGA) under O 2 (TA Instruments Q5000) to be 18.6 wt %, based on the total weight of the particles. FIG. 2 a ) shows further a scanning electron micrograph (ZEISS Auriga® electron microscope, 200 000 times magnification) of the nanoparticulate Fe 0.1 Zn 0.9 O obtained after calcining, while FIG. 2 b ) shows the carbon-coated Fe 0.1 Zn 0.9 O particles obtained after carbonizing with sugar. From the scanning electron micrograph, the average diameter of the Fe 0.1 Zn 0.9 O particles was determined as being about 20 nm to 30 nm. A comparison of the micrographs shows that the particle size after carbonizing was still in the range from 25 nm to 40 nm and was therefore largely preserved even after the carbon coating procedure. Example 2 Production of Co 0.1 Zn 0.9 O Particles Stoichiometric amounts of 4.102 g of zinc(II) gluconate hydrate (ABCR, 97% purity) and 0.449 g of cobalt(II) gluconate dihydrate (ABCR, >97% purity) were dissolved in 50 ml of deionized water (Millipore) to give a total metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+% purity) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The solid obtained was then dried at 300° C. for 10 to 20 minutes. The dried solid was then roughly comminuted by hand, and heated in an air atmosphere at 400° C. for 3 hours. During this time, the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours. The morphology of the Co 0.1 Zn 0.9 O particles was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 3 a ) shows the X-ray diffractogram and also the signals of the JCPDS file (Joint Committee of Powder Diffraction Standards) for Co 0.15 Zn 0.85 O with P63mc space group (JCPDS 01-072-8025). As can be seen from FIG. 3 a ), the signals observed for the calcined particles were unambiguously assignable to the signals of Co 0.15 Zn 0.85 O, which serves in this case too as a reference, since the crystal structure is therefore virtually identical and there is no in-house reference available for Co 0.1 Zn 0.9 O. FIG. 3 b ) shows a scanning electron micrograph (ZEISS Auriga® electron microscope, 200 000 times magnification) of the Co 0.1 Zn 0.9 O particles obtained. From the micrograph, the average diameter of the Co 0.1 Zn 0.9 O particles was determined as being about 25 nm to 40 nm. Example 3 Production of ZnO Particles 4.558 g of zinc(II) gluconate hydrate (ABCR, 97% purity) were dissolved in 50 ml of deionized water (Millipore) to a metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+% purity) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The resulting solid was then dried at 300° C. for 10 to 20 minutes. The dried solid was then roughly comminuted by hand and heated under an air atmosphere at 450° C. for 3 hours. During this time the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours. The morphology of the ZnO particles was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 4 a ) shows the X-ray diffractogram of the particles obtained, and also the signals of the JCPDS (Joint Committee of Powder Diffraction Standards) file for ZnO with P63mc space group (JCPDS 01-071-6424). As can be seen from FIG. 4 a ), the signals observed for the calcined particles were clearly assignable to the signals of ZnO. FIG. 4 b ) shows a scanning electron micrograph (ZEISS Auriga® Electron microscope, 200 000 times magnification) of the ZnO particles obtained. From the micrograph, the average diameter of the ZnO particles was determined as being about 25 nm to 40 nm. Example 4 Electrode Production For the production of electrodes, the uncoated and carbon-coated Fe 0.1 Zn 0.9 O particles produced according to examples 1a and 1b, and also the uncoated Co 0.1 Zn 0.9 O and ZnO particles produced according to examples 2 and 3, were used with conductive carbon and carboxymethylcellulose (CMC) as binder, in a weight ratio of 75:20:5. First of all, sodium carboxymethylcellulose (CMC, WALOCEL™ CRT 2000 PPA 12, Dow Wolff Cellulosics) was dissolved in deionized water, giving a solution containing 1.25 wt % of carboxymethylcellulose. The particles produced according to examples 1 to 3 and Super P® conductive carbon (TIMCAL®, Switzerland) as conductivity additive were added and the mixture was homogenized using a ball mill (Vario-Planetary Mill Pulverisette 4, Fritsch) at 800 rpm for 2 hours. The suspension thus obtained was applied with a doctor blade, with a wet film thickness of 120 μm, to copper foil (Schlenk). The electrode was dried in air at 80° C. for 2 hours and then at room temperature (20±2° C.) for 12 hours. Subsequently, circular electrodes with a diameter of 12 mm and an area of 1.13 cm 2 were punched out and dried under reduced pressure at 120° C. for 12 hours. The surface coverage was approximately 1.8 to 2.2 mg cm −2 . The surface coverage was determined by weighing of the pure foil and of the electrodes punched out. Electrochemical Investigations The electrochemical investigation of the electrodes produced according to example 4 took place in three-electrode Swagelok™ cells with lithium metal foils (Chemetall, “battery grade” purity) as counter electrodes and reference electrodes, or, in example 9, with sodium metal foils as counter electrode and reference electrode. The cell was assembled in a Glovebox (MBraun) filled with an inert argon gas atmosphere and having an oxygen content and water content of less than 0.5 ppm. An electrolyte-impregnated stack of nonwoven polypropylene web (Freudenberg, FS2226) was used as separator in a 1 M solution of LiPF 6 in a 3:7 mixture, based on the weight, of ethylene carbonate and diethyl carbonate (“battery grade” purity, UBE, Japan) as electrolyte. Because lithium foil was used as counterelectrode and reference electrode, the reported voltages are based on the Li + /Li reference. Only in example 9 are the reported voltages based on the Na + /Na reference. All Electrochemical investigations were conducted at a temperature of 20° C.±2° C. The potentiostat/galvanostat used was a Maccor 4300 battery test system. Comparative Example 5 Electrochemical Investigation of the Comparative Electrode Based on ZnO In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g. FIG. 5 shows the capacity characteristics of the composite electrode comprising ZnO particles at rising charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 685 mAh/g and an irreversible capacity loss of more than 700 mAh/g. The specific capacity obtained then dropped off rapidly, before stabilizing at above 200 mAh/g for an applied current density of 0.19 A/g. When the applied current density was increased further in steps, the specific capacity obtained continued to drop off, before going to just above 0 mAh/g for an applied current density of 9.5 A/g. When the applied current density, finally, was lowered to 0.095 A/g again, a specific capacity of about 310 mAh/g was obtained, which corresponds approximately to the theoretical specific capacity of ZnO (329 mAh/g), if the zinc present just forms an alloy with lithium reversibly. Example 6 Electrochemical Investigation of an Electrode Containing Fe 0.1 Zn 0.9 O Particles In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. In analogy to example 5, thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g. FIG. 6 shows the capacity characteristics of the composite electrode comprising Fe 0.1 Zn 0.9 O particles at rising charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 900 mAh/g and an irreversible capacity loss of about 500 mAh/g. The specific capacity obtained then dropped off slightly to start with, before stabilizing at about 730 mAh/g for an applied current density of 0.048 A/g. When the applied current density was increased further in steps, the specific capacity obtained dropped off gradually, before going to 0 mAh/g for an applied current density of 9.5 A/g. When the applied current density, finally, was lowered to 0.095 A/g again, a specific capacity of about 650 mAh/g was obtained, which corresponds approximately to twice the theoretical specific capacity of ZnO (329 mAh/g), but dropped off continuously thereafter. The electrodes therefore exhibited a cycling stability and specific capacity improved significantly relative to ZnO. Example 7 Electrochemical Investigation of an Electrode Containing Carbon-Coated Fe 0.1 Zn 0.9 O Particle Particles In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. In analogy to examples 5 and 6, thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g. FIG. 7 shows the capacity characteristics of the composite electrode carbon-coated Fe 0.1 Zn 0.9 O particles on increasing charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 810 mAh/g and an irreversible capacity loss of about 450 mAh/g. The cycling stability was significantly improved relative to the uncoated particles and also to the zinc oxide reference. In relation to shortened charging times and/or higher applied current densities as well, a significant improvement in the material was achieved. Thus, for example, even for an applied current density of 1.9 A/g, a specific capacity of about 350 mAh/g was obtained, which corresponds approximately to the theoretical capacity of graphite (372 mAh/g), but which as a general rule is not achieved for the same current density (corresponding to a charge rate of 5 C, meaning that the cell was fully charged or discharged in about 12 minutes) Where, lastly, the applied current density was lowered to 0.095 A/g again, an extremely stable specific capacity of about 730 to 740 mAh/g was obtained, which corresponded to more than twice the theoretical specific capacity of ZnO (329 mAh/g) and approximately to twice the theoretical specific capacity of graphite (372 mAh/g). The electrodes therefore showed, over all of the current densities applied, a cycling stability and specific capacity improved significantly relative to ZnO and also relative to the uncoated Fe 0.1 Zn 0.9 O particles. Example 8 Electrochemical Investigation of an Electrode Comprising Co 0.1 Zn 0.9 O Particles In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, a current density of 0.048 and 0.095 A/g was applied to the electrodes, for 10 cycles in each case, and the cell was discharged and charged to a potential of 0.01 V and to 3.0 V respectively. FIG. 8 shows the capacity characteristics of the composite electrode comprising Co 0.1 Zn 0.9 O particles on increasing charge and discharge rates over 21 cycles. At the start, the electrode showed a reversible specific capacity of about 970 mAh/g and an irreversible capacity loss of about 370 to 380 mAh/g. The cycling stability was therefore improved further relative to the uncoated Fe 0.1 Zn 0.9 O particles and also to the zinc oxide reference. When the applied current density was doubled, in each case after ten cycles, the specific capacity obtained remained approximately constant at about 940 mAh/g, and was therefore almost three times as high as the theoretical capacity of ZnO (329 mAh/g) and also higher by a factor of 2.5 than the theoretical capacity of graphite (372 mAh/g). The electrodes therefore exhibited a cycling stability and specific capacity substantially better than for ZnO. The specific capacity and cycling stability of the electrode based on Co 0.1 Zn 0.9 O are likewise better than those of the electrode based on uncoated Fe 0.1 Zn 0.9 O particles. Example 9 Electrochemical Investigation of an Electrode Comprising Carbon-Coated Fe 0.1 Zn 0.9 O Particles Against Sodium Metal In the first cycle, the cells were discharged and charged with a constant current density of 0.1 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. FIG. 9 shows the voltage profile of the composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles for the first two cycles. At about 150 mAh/g, the specific capacity obtained was indeed well below the specific capacity obtainable when using lithium-based systems, but is at least comparable with the current standard anode materials for sodium-based battery systems, for which cost advantages are generally rated higher than high energy densities. As can be seen from the complete overlap of the two charging operations, the storage of sodium ions in electrodes produced accordingly was highly reversible, moreover. Against sodium metal as well, therefore, the electrodes based on coated Fe 0.1 Zn 0.9 O particles exhibit a stable specific capacity and are therefore generally also suitable as a new anode material for sodium ion-based battery systems. Example 10 Production of Carbon-Coated Fe x Zn 1-x O Particles with Varying Iron Content Fe x Zn 1-x O particles were produced as described in example 1, step a), with the stoichiometric amounts of zinc(II) gluconate hydrate and iron gluconate dihydrate being adapted so as to give calcined Fe 0.02 Zn 0.98 O particles, Fe 0.04 Zn 0.96 O particles, Fe 0.06 Zn 0.94 O particles, Fe 0.08 Zn 0.92 O particles, Fe 0.1 Zn 0.9 O particles, and Fe 0.12 Zn 0.88 O particles. Determination of the morphology by X-ray powder diffractometry revealed all of the samples to be phase-pure with a particle crystallinity that dropped slightly as the iron content went up. Determinations were also made of the BET surface area of the particles and of their density, For this purpose, the specific surface area of solids was determined by means of nitrogen gas adsorption by the Brunauer-Emmett-Teller (BET) method. For this purpose an ASAP 2020 (Accelerated Surface Area and Porosimetry Analyzer, Micromeritics) was used. The density of the samples analyzed was determined using an AccuPyc II 1340 Gas Pycnometer (Micromeritics, helium). The BET surface area and density found in the samples are collated Table 1 below: TABLE 1 BET surface area Density Sample [m 2 /g] [g/cm 3 ] Fe 0.12 Zn 0.88 O 98 ± 0.3 5.5 ± 0.1 Fe 0.1 Zn 0.9 O 88 ± 0.3 5.4 ± 0.1 Fe 0.08 Zn 0.92 O 80 ± 0.1 5.4 ± 0.1 Fe 0.06 Zn 0.94 O 74 ± 0.1 5.3 ± 0.1 Fe 0.04 Zn 0.96 O 64 ± 0.1 5.4 ± 0.1 Fe 0.02 Zn 0.98 O 47 ± 0.1 5.5 ± 0.1 It was found that the density of the particles was in each case close to the density of ZnO, of 5.6 g/cm 3 . The particles were subsequently coated with about 20 wt % of carbon, based on the weight of the particles, by mixing them with sucrose and carrying out carbonization, as described in example 1, step b). Example 11 Electrochemical Investigation of Electrodes Containing Carbon-Coated Fe x Zn 1-x O Particles with Varying Iron Content Carbon-coated Fe 0.06 Zn 0.94 O, Fe 0.08 Zn 0.92 O, Fe 0.1 Zn 0.9 O and Fe 0.12 Zn 0.88 O particles produced according to example 10 were used for the electrochemical investigation. Electrode production took place as described in example 4. In the first cycle in each case, the cells were discharged and charged with a constant current density of 0.05 A/g (1 C{circumflex over (=)}1 A/g) to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, for ten cycles in each case, a current density of 0.05; 0.1; 0.2; 0.5; 1; 2 and 5 A/g was applied to the electrodes, and the cell was discharged and charged to a potential of 0.01 V and to 3.0 V respectively. The applied current density was then lowered again to 0.1 A/g. FIG. 10 shows the capacity characteristics of the composite electrodes comprising the carbon-coated Fe x Zn 1-x O particles on increasing charge and discharge rates over 70 cycles. Here, FIG. 10 a ) shows the capacity characteristics of the Fe 0.12 Zn 0.88 O particles, FIG. 10 b ) those of the Fe 0.1 Zn 0.9 O particles, FIG. 10 c ) those of the Fe 0.08 Zn 0.92 O particles, and FIG. 10 d ) those of the Fe 0.06 Zn 0.94 O particles. A comparison shows that for these particles, a higher iron content generally had a positive influence on the specific capacity achieved, for all discharge rates. As can be inferred from FIG. 10 , the electrodes comprising particles having an iron content in the range from Fe 0.08 Zn 0.92 O to Fe 0.12 Zn 0.88 O all exhibited a very good specific capacity and cycling stability over the current densities applied. Example 12 Production of Carbon-Coated Fe 0.1 Zn 0.9 O Particles with Varying Carbon Content Fe 0.1 Zn 0.9 O particles were produced as described in example 1, step a), and subsequently coated with carbon as described in example 1, step b), by mixing them with sucrose and carrying out carbonization, the amounts of sucrose being adapted so as to give Fe 0.1 Zn 0.9 O particles coated in each case with 5 wt %, 12 wt %, 16 wt %, and 20 wt % of carbon, based on the total weight of the particles. The morphology of the uncoated and coated particles was subsequently determined by X-ray powder diffractometry. It was found that the crystallinity of the particles rose with falling carbon content. Furthermore, the BET surface area of the particles and their density were determined as described in example 10. The BET surface area and density determined for the particles are collated in Table 2 below: TABLE 2 Carbon content BET surface area Density Sample [wt %] [m 2 /g] [g/cm 3 ] Fe 0.1 Zn 0.9 O 20 92 ± 2.1 3.6 ± 0.1 Fe 0.1 Zn 0.9 O 16 98 ± 1.6 3.7 ± 0.1 Fe 0.1 Zn 0.9 O 12 79 ± 0.8 4.2 ± 0.1 Fe 0.1 Zn 0.9 O 5 62 ± 0.2 4.9 ± 0.1 Fe 0.1 Zn 0.9 O 0 88 ± 0.3 5.4 ± 0.1 It was found that the BET surface area varied, with the specific surface area in a range from ≧12 wt % to ≦20 wt % of carbon being higher than for 5 wt % of carbon, whereas the density rose with falling carbon content. This shows that particles having a carbon fraction in the range from 5 wt % to 20 wt %, especially in the range from 12 wt % to 20 wt %, hold out the expectation overall of a good active material for electrodes with high capacity. The research which led to this invention was supported by external funding from the Seventh Framework Programme of the European Union (FP72007-2013) under Project No. ORION 229036.

The invention relates to a method for producing carbon-coated, transition metal-doped zinc oxide particles and the use thereof as electrode material for alkali metal ion batteries and, in particular, lithium ion batteries.

FIELD OF THE INVENTION This invention relates to a method of manufacturing a radio frequency circuit in a thin flexible package. More specifically, the invention relates to making a thin leadframe antenna and radio frequency circuit used as a radio frequency tag. BACKGROUND OF THE INVENTION The prior art connects integrated circuit chips (chip) to thin metallic foils, e.g., leadframes. In these methods, the chip is affixed on top of the leadframe, then the leadframe is connected to electrical connections on the chip by wire bonding techniques. Because of the fragile nature of the bonding, the connections are encapsulated for support. The types of bonding generally employed are ultrasonic, thermosonic, or thermocompression wire bonding. A thin gold or aluminum wire is bonded by one of the techniques to a foil leadframe. Typically leadframes are connecting and supporting elements to provide connections between the chip contacts and other electrical connections. Therefore, they normally have a thickness of 150 to 200 microns to provide some rigidity. PROBLEMS WITH THE PRIOR ART The prior art methods have difficulty in producing transponders that are thin and flexible, particularly if the transponders have a leadframe structure. This is because the prior art leadframe structures require that the chip be attached to the surface of the leadframe (adding to the thickness of the chip and leadframe to the package), use the leadframe as an intermediate connection which tends to add additional layers and thickness to the package), and require wire bonding (which also adds to the package thickness because or the "loop height" of the wire bond.) Further, the leadframe used in the prior art has to be of a minimum thickness to provide support and rigidity to the package. OBJECTS OF THE INVENTION An object of this invention is an improved method of manufacturing a thin radio frequency transponder. An object of this invention is an improved method of manufacturing a thin radio frequency transponder with a leadframe antenna. An object of the invention is a method of making a flexible radio frequency tag apparatus with a thin flexible protective lamination. SUMMARY OF THE INVENTION The present invention is a method of making thin, flexible transponders with a leadframe structure (antenna). A leadframe strip that is thin (75-100 microns), having a low thermal mass and lower thermal conductance, is used. Leadframe antennas are created as patterns in the leadframe strip and connections to the leadframe antennas are attached directly to circuit chip connections. No intermediate connection layers or wiring is required and the patterns in the leadframe strip become an integral component, the antenna, of the transponder. The leadframe strip having leadframe antenna "cutouts" is transported to a point where a chip is mechanically and electrically attached directly to the leadframe antenna. The chip and parts of the leadframe antenna are optionally encapsulated. A battery also can be attached to the chip in the process. Depending on the embodiment, support bars holding the leadframe antenna to the leadframe strip are cut, the package is sealed (laminated or molded), and a sealed component is excised in different sequences to produce a final product. Intermediate support (positioners) for the thin leadframe are optionally provided so that the chip can be positioned at the connection end of the leadframe antenna and so that the thin leadframe antenna does not geometrically deform (short out) during the assembly process. For example, the spacing of multi-element antennas is maintained. A protective surround can be added to cover the package and to provide added structural support for the package while still permitting the package to be thin and flexible. Various structures made by invention are disclosed in U.S. patent application Ser. No. 08/621,184 to Brady et al. entitled "Thin Radio Frequency Transponder with Leadframe Antenna Structure" filed on the same day as this application and which is herein incorporated by reference in its entirety. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow diagram showing the steps of making the radio frequency tag (transponder component). FIG. 2 is a drawing showing one preferred embodiment of a thin lead frame strip used to make thin antennas for the radio frequency tag. FIG. 3 is drawing showing an alternative preferred embodiment of the leadframe strip of thin antennas for the radio frequency tag. FIG. 4, comprising FIGS. 4a-4c, is a drawing showing a method of bonding of the circuit chip to one of the thin leadframe antennas. FIG. 5 is a drawing showing a preferred embodiment for the method of encapsulation (FIG. 5B) of the chip bonded (FIG. 5A) to the thin leadframe antenna(s). FIG. 6 is a drawing showing an alternative preferred embodiment for the method of encapsulation of the chip bonded to the thin antenna. FIG. 7 is a drawing showing a method for the attachment of a battery to the thin leadframe structure. FIG. 8 is a drawing showing a method for the cutting of support bars holding individual thin antennas to the leadframe strip. FIG. 9 is a drawing showing one preferred embodiment of a method for sealing (laminating) the strip of thin leadframe antennas with bon(ed(l chips. FIG. 10 is a drawing of an alternative method for the sealing (molding) the strip of thin leadframe antennas with bonded chips. FIG. 11 is a drawing of a method for excising individual radio frequency tags from a laminated leadframe strip to produce a component transponder. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a flow diagram showing the steps in the manufacture of the radio frequency tag. In step 400, chips are joined to individual antennas on a transported 150 leadframe antenna strip 100. The chips are fabricated as integral parts of a semniconductor wafer 200, the I/Os on the chips are bumped 210, the wafer is thinned 220, and the wafer is diced and individual chips are picked 230. Steps 200, 210, 220, and 230 are well known in the semiconductor industry and are described in detail in the following: "Silicon Processing for The VLSI Era", vol. 1, by S. Wolf and R. N. Tauber, Lattice Press, Sunset Beach, Calif., 1986, ISBN 0-961672-3-7; "Backgrinding Wafers For Maximum Die Strength", by S. Lewis, in Semiconductor International July 1992, p.86; "Chip On Board Technologies For Multichip Modules", edited by John H. Lau, Van Nostrand Reinhold Publishing Company, New York, 1994, ISBN 0-442-01441-4, which are herein incorporated by reference in their entirety. A leadframe (antenna) strip 100, FIG. 2, is a thin etched or stamped foil, typically manufactured from a thin foil of copper, copper-alloy, or nickel-iron alloy by stamping or etching. The etching or stamping creates patterns on the leadframe strip 100 that become leadframe antennas 110. The leadframe strip 100 comprises a supporting frame 130 with sprocket holes 135, the individual leadframe antennas 110, support bars 120, support rails 850, and inner bonding leads 115. In a preferred embodiment, the antenna strip 100 is between 2.8 mils and 10 mils (i.e. 70 microns and 250 microns) thick. More preferably, the antenna strip is between 75 microns and 110 microns, typically 100 microns thick. The leadframe strip 100 of this thickness has a low thermal mass and lower thermal conductance which helps the circuit chip to be directly attached (see FIG. 4 below) to the leadframe strip 100. Note that the antennas 110 shown in FIGS. 2 and 3 are loop antennas. However, the leadframe antennas 110 can be of any type, for example those disclosed in the patent application entitled "Thin Radio Frequency Transponder with Leadframe Antenna Structure" incorporated above. The type of the antenna is determined by the pattern that is produced, e.g., stamped/etched in the leadframe antenna strip 100. This method can be applied to any of these and other antenna patterns. In a preferred embodiment, FIG. 3, the leadframe strip 100 comprises a supporting frame 130, individual antennas 110, support bars 120, support rails 850, and inner bonding leads 115, as shown in FIG. 2. The strip 100 also has positioner strips (or positioners) 240. The strip 100 is transported 200 by known means. The positioner strips 240 can be added during the manufacturing process of the strip 100 and consist of narrow, preferably 2 mm to 5 mm wide strips of polyimide or other plastic adhered to the antennas 110 and supporting frame 130 by means of adhesive such as butyral phenolic. Other adhesives that may be employed are acrylics, silicones, or modified epoxies. The positioner 240 also can be a sheet with one or more apertures in the locations where the circuit chips are attached. The positioner strips 240 are spooled 250 onto the leadframe strip by known methods. See "Microelectronics Packaging Handbook", edited by R. Tummala, Van Nostrand Rheinhold, New York, 1989 which is herein incorporated by reference in its entirety. Note that the positioner strips 240 are spooled 250 onto the leadframe strip 100 after the leadframe strip 100 is etched or stamped. Also the positioner strips 240, in most embodiments, support only a portion of the leadframe strip 100. The chip bonding, step 400, shown in FIG. 4, is accomplished by first placing the individual antenna 110 in alignment with the chip 440 such that the inner bonding leads 115 of the antenna 110 are aligned to the bumps 420 on the chip 440 as shown in FIG. 4a. Next, FIG. 4b, a bonding head 430 is placed in contact with the inner lead 115 and the inner lead 115 is pressed to the bump 420. Through the application of heat and pressure, the bond is completed and the chip and antenna combination is lifted from the retention apparatus 450 as shown in FIG. 4c. Alternate methods of bonding include: thermosonic; lasersonic; soldering; and wirebonding. See U.S. Pat. No. 4,970,365, entitled "Method and Apparatus for Bonding Components Leads to Pads Located on a Non-rigid Substrate", to Chalco issued on Nov. 13, 1990 that is herein incorporated by reference in its entirety. The chip encapsulation process, step 500, shown in FIG. 5, is accomplished by the application of a chip face encapsulant material (FIG. 5B) on the chips 440 that are attached to the leadframe strip 100. Typically, an epoxy 520 such as Dexter Hysol 4323 is applied. The epoxy 520 is contained within a dispenser 510 which is brought in close proximity to the chip surface 515. The epoxy 505 is dispensed in drops 520 to form a dome of encapsulant 530 over the surface of the chip 515. Curing of the epoxy is done at an elevated temperature, e.g. 150 C. for approximately 4 hours. Other chip encapsulants may be chosen from among the available modified epoxy resins manufactured by Dexter Hysol, Abelstik, and Epotek, for example encapsulants that have faster cure cycles. An alternatively preferred embodiment for the chip encapsulation, step 500, is shown in FIG. 6, and is accomplished through the addition of a novel overlayer 610 to the surface of the leadframe 615. The overlayer 610 is a polyimide or other suitable polymer. The space 640 between the overlayer 610 and the chip 440 is filled by the capillary action of the encapsulant material 505. The nozzle 620 of the dispenser 510 is placed adjacent to the space 640. The encapsulant material 505 then flows into and fills the space 640. Curing of the encapsulant is done at an elevated temperature, e.g. 150 C. for 4 hours for Hysol 4511. Other suitable encapsulants are manufactured by the companies mentioned above. Note that in FIG. 6, the chip is shown on top of the leadframe antenna 110 while in FIG. 5A the chip is shown below the leadframe antenna. In a preferred embodiment, the overlayer 610 has a size and a position so that the overlayer extends past the edges of the chip, i.e., is positioned at least over the entire chip surface 515. The overlayer 610 forms a "dam" which produces a capillary action when the encapsulation material is dispensed so that the encapsulation material reflows over the entire chip surface 515. After the encapsulation material cures, the encapsulant provides a mechanical connection that connects the leadframe antenna 110 to the chip surface 515 and bumps 420. This mechanical connection provides support for the antenna 110 bonding leads 115, chip surface 515, and bumps 420 while allowing the antenna 110 and bonding leads 115 to flex without breaking. The cured encapsulant also provides environmental protection for the chip surface against mechanical and chemical damage. The embodiment shown in FIG. 6 uses a structure that has the leadframe antenna 110 "sandwiched" between the overlayer 610 and the chip 440. This is done (see FIG. 5A) by using a cutting tool 580 that cuts 582 the overlayer 610 from a strip of polymer tape 585 and places 587 the overlayer 610 on the leadframe antenna 110 in a position over the chip 440 surface 515. Optionally, a battery may be attached 710 to the leadframe structure 110. The battery 700, shown in FIG. 7, typically has protruding contact tabs 720 which are brought into alignment with contact pads 730 on the leadframe strip 740. This leadframe strip 740 has additional connecting structures (730,735), in its patterns, for mechanically and electrically connecting the battery 700 to power input contacts 770 on the active chip 440A. A bonding head 750 is brought into place to make the bonds. The bonds may be accomplished by soldering, thermosonic, or laser-sonic bonding. In one preferred embodiment, spot welding 770 is used to attach the battery 700 contact pads 720 to the connecting structures 730 by fusing the metals making up the contact pads 720 and connecting structures 730. By using spot welding, similar or dissimilar metals can be fused together. Spot welding is fast and localizes the heat to the fused area without overheating the chip 440A or battery 700. Spot welding 770 also is fluxless so that corrosive materials arc not introduced to the electrical contacts. Spot welding 770 produces a low impedance connection and provides good mechanical strength at the fused area so that structural support is given at the fused area. In step 800, each of the support bars 120 is severed 830 by a cutting tool 820 as shown in FIG. 8. During this severing 830, the antenna 110 is electrically and mechanical separated from the leadframe strip 100 and the supporting frame 130 by cutting the support bars 120. Alternatively, the cutting tool 820 can sever 830 the antenna 110 at any point (particularly for dipole antenna structures) to trim or establish a different resonant antenna length. Although the antenna 110 is mechanically separated from the leadframe strip 100, in a preferred embodiment, the leadframe antenna 110 is still mechanically supported by the positioner strips 240. This allows the antenna 110 to be further processed without being mechanically distorted. That is, the positioner strips 240 maintain the geometric integrity of the antenna. Note also that the support rails 850, part of the supporting frame 130, are not cut (severed) 830 in a preferred embodiment, so that the support frame 130 can still be used to transport the components 860 (leadframe antenna 110 and chip 440.) In step 900, the package is sealed. In a preferred embodiment, FIG. 9, a strip 910 of components 860 is fed between two heated rollers 930. The strip 910 is the leadframe strip 100 with the chips attached, and in some embodiments, severed 800. The strip 910 is transported by a transporter or hitch feeder (not shown) that moves 915 the strip 910. See U.S. Pat. No. 5,052,606, entitled "Tape Automated Bonding Feeder" Cipolla et al. issued! on Oct. 1, 1991 that is herein incorporated by reference in its entirety. As strip 910 of components 860 moves through the rollers 930, sealing material 920 is also directed between the rollers 930. Pressure is exerted by the rollers 930 on the sandwich of materials. Heat is transferred from the heated rollers 930 to make the seal and create the lamination on one or both sides. Typically the materials are heated to 200 degrees C. Accordingly, where positioners 240 are used, the positioners 240 may reflow during this laminating process. Materials used as lamination materials include polyester/ethyl vinyl acetate PET/EVA, polypropylene sulfone PPS, or polyester PET. Other lamination materials include pa per, cardboard, polymers, polyethylene. The sealing (lamination) material can also have multiple layers, each layer being any of the materials above. Alternatively, the strip 910 can be transported through more than one lamination sealing process 900. In an alternative embodiment, FIG. 10, the sealing of the packages 900 is accomplished by injection molding 1000 instead of the lamination in FIG. 9. A strip of components 1005 is placed in a mold 1010. The two halves of the mold 1030 and 1040 are brought together and molding material 1025 is introduced through a groove 1020. Other molding techniques 1000 include reaction injection molding (RIM), compression molding, blow molding, or transfer molding. The molding 1000, can also be performed by dipping in a liquid sealing material such wax, or Dow-Corning silicone rubber, or Humiseal. These and other techniques for package sealing are described in the book, "Microelectronics Packaging Handbook", incorporated above. In an alternative embodiment, the support bars 120 are not cut, i.e, process 800 is omitted before the lamination in process 900. In this embodiment, the positioners 240 can be attached or alternatively need not be attached. (See FIG. 3.) The leadframe antenna 110 on the component 860 is structurally supported by the lamination in process 900 and therefore does not need to have positioners 240. In a later stop (see FIG. 11 below), the component 860 is excised. In this embodiment, a small part or the leadframe antenna is exposed to the environment at the points where the antenna 110 is excised. However, the component 860 can be dipped after the excising 110 to completely seal the exposed ends. Dipping techniques are known. In an another alternative embodiment, the support bars 120 are not cut, i.e. process 800 is omitted before the molding process 1000 (in lieu of the lamination 900.) In this embodiment, the positioners 240 can be attached or alternatively need not be attached. (See FIG. 3.) In this embodiment, the leadframe antenna 110 on the component 860 is structurally supported by the molding in process 1000. In a later step (see FIG. 11 below), the molded component 860 is excised 1100 from the lead frame strip. In this embodiment, the ends (either outside of the molded or at the cut edge of the mold) of the antenna 110 are exposed to the environment. To cover the antenna 110 totally, the molded component 860 can be picked up and dipped or laminated to totally cover the antenna 110. In alternative embodiments of molding 1000, the mold can be large enough so that the circuit chip 440 and all parts of the leadframe antenna 110 are hermetically sealed by the mold. Where positioners 240 are used before the molding 1000, the positioners 240 can be made of a material that is compressed during the molding 1000. The molding 1000 can also cause the positioners 240 to reflow during the molding. Positioners 240 made of polyimide would compress but not reflow during molding 1000. Positioners 240 made of some thermoplastics also would compress but not reflow during molding 1000. Positioners 240 made of other thermoplastics can be made to compress and reflow during molding 1000. In step 1100, shown in FIG. 11, the completely sealed (laminated 920 and/or molded) component 1110 is cut or excised 1100 from the strip 1120 by means of a known cutting tool 1130. The cutting tool 1130 cuts the lamination 920 so that the sealed component 1110 is separated from the laminated leadframe strip 1120. The component 1110 is therefore covered by a protective surrounding 920A that is the part of the lamination 920 cut away by the cutting tool 1130. (See patent application "Thin Radio Frequency Transponder with Leadframe Antenna Structure" incorporated above.) This protective surrounding 920A seals all parts of the sealed component 1110 from the environment. Given this disclosure, alternative equivalent embodiments would become apparent to one skilled in the art. These embodiments are within the contemplation of the inventors.

Manufacturing of a novel thin and flexible radio frequency (RF) tag with a stamped metal leadframe antenna is disclosed. The tag is made by transporting a leadframe strip having leadframe antenna "cutouts" to a point where a chip is mechanically and electrically attached directly to the leadframe antenna. A battery can be attached to the chip in the process. Processes to cut support bars holding the leadframe antenna to the leadframe strip, seal the package (by lamination or molding), and to excise the sealed component are performed in various orders to produce a final product. Intermediate support (positioners) for the thin leadframe are optionally provided add structural support to the antenna while the sealed component is made. A protective surround can be added to cover the package and to provide further structural support for the package while still permitting the sealed component to be thin and flexible.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode module, more particularly to a light emitting diode module having a latching component for conveniently installing the light emitting diode thereon or unloading the light emitting diode therefrom. 2. Description of Related Art A light emitting diode (LED) is a device for transforming electricity into light. When a current flows through a junction comprising two different semiconductors, electrons and holes combine to generate light. LEDs are small, inexpensive, with low power requirements and an extremely long working lifetime under specific conditions; more and more LED modules with different capabilities are being developed. However, the LEDs are sensitive to temperature and may be permanently damaged by excessive temperatures. High temperature performance of LEDs is an adverse aspect of LED technology that has not been satisfactorily resolved. As the LEDs are used for a long time and more power is added to the LEDs, heat generated by the LEDs must be quickly removed therefrom to prevent them from becoming unstable or being damaged. Accordingly, LED modules with heat dissipation devices are needed. Generally, the LED modules have thermal management components with good heat dissipation qualities. Usually, the LED usually has a smaller volume and it is different to secure the LED to the thermal management component. What is needed, therefore, is an LED module having a latching component for conveniently installing the LED thereto or unloading the LED therefrom. SUMMARY OF THE INVENTION An LED module includes a latching component, a frame holding an LED thereon, a heat spreader located in the latching component and a heat transfer member having a heat-dissipating unit remote from the LED and a heat pipe thermally connecting the heat spreader, the LED and the heat-dissipating unit together. The latching component cooperates with the heat spreader to tightly press the frame to be attached on the heat spreader. The heat transfer member thermally connects with the heat spreader and transfers heat from the LED to an ambient environment. The latching component has two spring pieces fixed therein. The two spring pieces are electrically connected with a power source. Furthermore, the two spring pieces push the frame toward the heat pipe and the heat spreader and electrically connect with the frame and the LED. Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. FIG. 1 is an exploded, schematic view of an LED module in accordance with a preferred embodiment of the present invention; FIG. 2 is an enlarged rear end view of a latching component of the LED module of FIG. 1 ; FIG. 3 is an assembled view of FIG. 1 ; and FIG. 4 is an enlarged, partial view of FIG. 3 with a part thereof being cut away. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1-4 , an LED module in accordance with a preferred embodiment of the present invention comprises a latching component 10 , a frame 20 mounting an LED 800 thereon and located in the latching component 10 , a heat spreader 30 attached to the frame 20 and a heat-transfer member having a heat pipe 40 and a heat-dissipating unit 50 . The heat pipe 40 thermally connects the frame 20 with the heat-dissipating unit 50 . The latching component 10 is made of elastic plastic and has a cylindrical configuration. The latching component 10 comprises a cylindrical body 110 . The body 110 has a top surface 120 on a front end portion thereof and a rear end portion (not labeled) opposite the front end portion. A round opening 122 is defined in a center of the top surface 120 for offering the LED 800 an exit so that the LED 800 is exposed over the top surface 120 of the body 110 . Three elastic legs 130 are extended from an edge of the rear end portion of the body 110 and are evenly spaced from each other along a circumference of the body 110 . Each leg 130 comprises a position portion 132 extending from an edge of the rear end portion of the body 110 and a hooked portion 134 extending inwardly from the position portion 132 and having an acute angle to the position portion 132 . A pair of spring pieces 140 are formed on an inner surface of the top surface 120 of the body 110 . Each spring piece 140 comprises a strip-shaped body 142 and a pair of fixed claws 144 extending from two opposite end portions of the strip-shaped body 142 . The fixed claws 144 are upwardly and outwardly curved to be parallel to the body 142 and each defines a hole 146 therein. A pair of projections 148 are formed on the inner surface of the top surface 120 of the body 110 and engaged in the holes 146 of the fixed claws 144 of each spring piece 140 to position the spring piece 140 on the inner surface of the body 110 of the latching component 10 . The frame 20 has a round plate 200 , such as a printed circuit board and the LED 800 is electrically connected to the frame 20 to emit light. The frame 20 comprises a top surface on which the LED 800 is mounted and a bottom surface on an opposite side to the top surface. Three pins 210 (only one shown) are formed on the bottom surface of the frame 20 . Since the LED 800 inherently has a too small surface available to sufficiently transfer heat therefrom, the heat transfer member is used to transfer the heat to a place where it can be dissipated. The heat pipe 40 and the heat-dissipating unit 50 can satisfy this demand. Firstly, the heat spreader 30 is used to spread the heat from the LED 800 . The heat spreader 30 can be made of aluminum or copper. The heat spreader 30 has a cylindrical body 300 with a hollow cylindrical portion in a center thereof. A circular passage 310 is defined through the center of the heat spreader 30 . Three slots 320 are defined in an outer surface and along an axial direction of the body 300 of the heat spreader 30 , corresponding to the legs 130 of the latching component 10 . The three slots 320 divide the circumference of the body 300 of the heat spreader 30 into three equal parts. Three positioning holes 322 are defined in a front-end portion of the body 300 of the heat spreader 30 and corresponding to the pins 210 of the frame 20 . The heat pipe 40 has an evaporating section 42 engaged in the passage 310 of the heat spreader 30 , and a condensing section 44 perpendicular to the evaporating section 42 and inserted through the heat-dissipating unit 50 . The heat-dissipating unit 50 comprises a plurality of metallic fins 52 . The fins 52 are parallel to and separate from each other. A through hole (not shown) is defined in a center of the heat-dissipating unit 50 , transversely extending though all of the fins 52 . The evaporating section 42 and the condensing section 44 of the heat pipe 40 are fixed in the passage 310 of the heat spreader 30 and the through hole of the heat-dissipating unit 50 respectively by soldering; accordingly, the condensing section 44 of the heat pipe 40 is thermally engaged with the metallic fins 52 , and the evaporating section 42 of the heat pipe 40 is thermally engaged with the heat spreader 30 . The heat pipe 40 is preferably included to quickly transfer the heat from the LED 800 to the heat-dissipating unit 50 which can be arranged at a location remote from the LED 800 and can have a large heat-dissipating surface available to facilitate heat dissipation. In assembly, the evaporating section 42 of the heat pipe 40 extends in the passage 310 of the heat spreader 30 by soldering and a front end of the evaporating section 42 projects out from the passage 310 so as to absorb the heat from the LED 800 quickly. The pins 210 of the frame 20 are inserted and positioned in the positioning holes 322 of the front end portion of the body 300 of the heat spreader 30 . The bottom surface of the frame 20 is attached on the top surface of the evaporating section 42 of the heat pipe 40 . The latching component 10 covers the heat spreader 30 and the legs 130 of the latching component 10 slide along the slots 320 of the heat spreader 30 until the hooked portions 134 of the legs 130 exert spring forces to clasp and engage a rear end portion of the heat spreader 30 . Accordingly, the latching component 10 is secured to the spreader 30 by the hooked portions 134 engaging the rear end portion of the heat spreader 30 . As the legs 130 of the latching component 10 engage the heat spreader 30 to exert the latching forces thereon, the bodies 142 of the spring pieces 140 of the latching component 10 also exert spring forces to press the frame 20 to be tightly attached to the heat spreader 30 , and the frame 20 is thus tightly sandwiched between the latching component 10 and the heat spreader 30 . The bodies 142 resiliently engage with positive and negative electrodes 220 on the round plate 200 , whereby the spring pieces 140 are electrically connected with the round plate 200 and the LED 800 . Wires (not show) which are connected to a power source can be extended through two holes 150 (only one shown) defined in a periphery of the latching component 10 to electrically connect with the spring pieces 140 . Thus, the round plate 200 and the LED 800 are electrically connected with the power source via the spring pieces 140 . In operation, the evaporating section 42 of the heat pipe 40 absorbs the heat from the LED 800 . A minor part of the heat is conducted to the heat spreader 30 by the evaporating section 42 of the heat pipe 40 and a major part of the heat is directly transferred to the fins 52 of the heat-dissipating unit 50 ; the heat from the LED 800 is thus quickly removed to avoid a high temperature performance of the LED 800 and ensure that the LED 800 operates at a normal working temperature. Furthermore, the heat pipe 40 transfers the heat generated by the LED 800 to the heat-dissipating unit 50 which is located at a location remote from the LED 800 and thus has a large heat-dissipating surface available to facilitate heat dissipation. In the preferred embodiment of the present invention, the frame 20 is sandwiched between the latching component 10 and the heat spreader 30 . The frame 20 is secured on the heat spreader 30 by the legs 130 of the latching component 10 clasping on the heat spreader 30 and it is convenient for installing/unloading the LED 800 to/from the heat spreader 30 . Moreover, the heat spreader 30 is located in the latching component 10 to be coupled as a unit, which is very advantageous in view of the compact size and portable requirement of heat dissipation devices with the LEDs. It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples here described merely being preferred or exemplary embodiments of the invention.

An LED module includes a latching component, a frame holding an LED thereon, a heat spreader located in the latching component and a heat transfer member having a heat-dissipating unit remote from the LED and a heat pipe thermally connecting with the heat spreader, the LED and the heat-dissipating unit. The latching component cooperates with the heat spreader to tightly press the frame being attached on the heat spreader. The heat transfer member thermally connects with the heat spreader and transfers heat from the LED to an ambient environment. The latching component has two spring pieces pushing the frame toward the heat spreader and the heat pipe. The spring pieces electrically engage with the frame to thereby electrically connect with the LED.

FIELD OF THE INVENTION The present invention relates to storage containers in general, and in particular, to storage containers for flat, objects, wherein the storage containers also have apparatus for displaying a selected object without having to remove that object from the container. BACKGROUND OF THE INVENTION Flat objects such as floppy diskettes, phonographic records and `compact discs` are often kept in generally rigid, closable storage containers. These storage containers prevent mechanical damage to the stored objects, reduce the exposure of the objects to dust, and, in general, provide a convenient means of storing and transporting floppy diskettes and compact discs. The objects are stored parallel to each other, inclined at a small angle to the base of the container. Due to the relatively large number of objects that may be stored in a single container, e.g. about 20 or 30, searching for a particular diskette or compact disc may be tedious and time-consuming. Described in U.S. Pat. No. 4,609,231 is a container for storing planar objects. The container enables a selected object to be rapidly located by lifting successive stored planar objects so as to display a portion thereof. To achieve this there is provided a rotatable camshaft extending along the length of the container, and a plurality of cams corresponding to a plurality of support arms for stored planar objects. The cams are spaced along the camshaft and are also spaced radially thereabout so that axial rotation of the camshaft causes successive lifting engagement of a single support arm by its corresponding cam so as to lift and expose a portion of the object on each support arm. It would be advantageous to provide a means of displaying an entire surface portion of a stored object so as to more readily permit identification thereof. It would also be advantageous to provide a means of successively displaying stored flat objects by less complex means than those described in the above-referenced U.S. Patent. U.S. Pat. No. 3,812,975 describes phonograph record holding apparatus including a plurality of pivotal record holding members which are constructed and arranged such that the forward tilt of an end one of the members is operative to cause the automatic forward pivoting of the remainder of the members. U.S. Pat. No. Re. 27,462 describes a photograph record rack having a frame and a plurality of spaced parallel axially pivoted record holding members. The holding members are constructed and arranged such that the tilting of one member is operative to cause the automatic pivoting of an adjacent holding member. Disadvantages inherent in both of the above-described U.S. patents is that they provide no means for controlling the automatic successive tilting of adjacent, hitherto non-tilted holding members, and that the construction of both devices is inherently complex and may result in jamming thereof. The following patents are also noted as describing storage apparatus for flat objects and including features of either static display of stored objects or individual manual pivoting of compartments for storing a plurality of flat objects or of single object compartments: U.S. Pat. Nos. 3,100,671; 3,556,620; 4,239,307; and 4,684,019. SUMMARY OF THE INVENTION The present invention seeks to provide a storage container for flat objects, wherein the container also has apparatus for successively displaying an entire surface portion of each stored object so as to enable rapid visual scanning thereof, thereby overcoming disadvantages of known art. There is provided, therefore, in accordance with an embodiment of the invention, storage apparatus for flat objects including a container configured to hold a plurality of flat objects; and apparatus associated with the container for selectably rotating successive ones of the objects between first and second positions so as to display a selected surface of each successively rotated object. Additionally in accordance with an embodiment of the invention, the apparatus for selectably rotating includes a plurality of spaced apart support elements mounted for rotation about a plurality of respective, parallel pivot axes, each the support element being configured to support a single flat object in either of the first or second positions; and apparatus for selectably engaging successive support elements so as to cause pivoting thereof about the pivot axes so as to rotate successive ones of the flat objects between the first and second positions. Further in accordance with an embodiment of the invention, the container includes a base and the plurality of pivot axes are oriented generally parallel to the base, each support element defining a support portion extending generally away from the base and further defining a protrusion extending from the pivot axis towards the base, the apparatus for selectably engaging being operable to successively engage each protrusion so as to cause pivoting of each support element. Additionally in accordance with an embodiment of the invention, the apparatus for selectably engaging includes an engagement element mounted for translation along an axis transverse to the pivot axes as to successively engage and cause pivoting of each support element; and apparatus for selectably displacing the engagement element along the transverse axis. Further in accordance with an embodiment of the invention, the engagement element includes a movable cam member having an internally threaded bore and which is configured to engage each protrusion, and the apparatus for selectably displacing includes a drive screw mounted along the transverse axis and extending through the threaded bore so as to engage the cam; apparatus for rotating the drive screw; and apparatus for preventing rotation of the cam member about the drive screw so as to cause linear translation of the cam along the drive screw and thereby cause successive engagement of the protrusions of the support elements by the cam. According to an alternative embodiment of the invention, the apparatus for selectably engaging includes an elongate rotatable member having first and second ends and mounted along an axis transverse to the pivot axes; and a helical screw member mounted onto the rotatable member so as to be rotatable therewith and configured to engage successive protrusions when the rotatable member is rotated. According to yet a further embodiment of the invention, the movable member includes an elongate cam member mounted for movement along its longitudinal axis and defining a plurality of cam portions equal to the number of support elements and arranged along the cam member so as to successively engage and rotate predetermined support elements. In accordance with an additional embodiment of the invention, protrusion of each support element is made of a magnetic material and the engagement element is a magnet. In accordance with a further embodiment of the invention, the apparatus for successively rotating each of the objects between first and second positions includes apparatus for successively engaging the objects so as to cause successive rotation thereof. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings, in which: FIGS. 1A and 1B are respective cut-away perspective and side views of storage and display apparatus for flat objects, employing a single cam mounted onto a drive screw and constructed in accordance with an embodiment of the invention; FIG. 2 is an enlarged perspective illustration of a single support element used in the storage and display apparatus of FIGS. 1A and 1B; FIGS. 3A-3C illustrate the rotation and display of a single object stored in the storage and display apparatus of FIGS. 1A and 1B; FIGS. 4A and 4B are respective cut-away perspective and side views of storage and display apparatus for flat objects, similar to the apparatus of FIGS. 1A and 1B but employing support elements configured so as to permit closer spacing than that permitted by the support elements employed in the apparatus of FIGS. 1A and 1B; FIG. 5 is an enlarged perspective illustration of a single support element used in the storage and display apparatus of FIGS. 4A and 4B; FIG. 6 is a cut-away side view of storage and display apparatus employing a single cam member mounted onto a pulley system; FIG. 7 is a cut-away side view of storage and display apparatus employing a 360° turn helical cam member; FIG. 8 is an enlarged view taken along line VIII--VIII in FIG. 7; FIG. 9 is a cut-away side view of storage and display apparatus employing a cam member defining a plurality of cam portions; FIG. 10 is a cut-away side view of storage and display apparatus generally similar to that illustrated in FIGS. 1A, 1B, 4A and 4B, but employing support elements constructed according to yet a further alternative embodiment of the invention; FIG. 11 is a cut-away side view of storage and display apparatus employing magnetic rotation apparatus; FIG. 12 is a cut-away side view of storage and display apparatus employing gas jet rotation apparatus; FIG. 13 is a cut-away side view of storage and display apparatus employing gas jet rotation apparatus constructed according to an alternative embodiment of the invention; and FIGS. 14A-14D are diagrammatic illustrations of the reversal in direction of the gas jet apparatus of FIG. 13. DETAILED DESCRIPTION OF THE INVENTION Reference is made to FIGS. 1A and 1B, which illustrate storage and display apparatus for flat objects, such as floppy diskettes and compact discs. The apparatus, referenced generally 10, includes a boxlike container 12 for storing a plurality of the flat objects, indicated at 14. Mounted within the container 12 is apparatus 16 (FIG. 1B) for successively rotating each of the objects 14 between first and second relatively inclined positions, shown generally at 13 and 15 respectively, so as to display a selected surface 18 of each object. The rotation of each stored object 14 causes virtually the entire surface 18 of each object to be displayed. As this virtually maximizes the amount of visual information available to a person searching for a particular object it greatly eases the search for a specific object 14 stored among a plurality of the objects. Referring now also to FIG. 2, apparatus 16 includes a plurality of spaced apart support elements 20 mounted by a plurality of parallel pivot members 22 into a mounting member 19 (FIGS. 1A and 1B). Each support element 20 is configured to support a single object 14 in either of the first or second positions as may be defined by transverse stop members 21 forming part of, or mounted onto mounting member 19. Each support element 20 may be rotated about a pivot axis 23, defined by pivot member 22, by engagement with a cam member 24 (FIG. 1B). In the shown embodiment, each support element defines a first portion 26 extending away from base 28 of the container 12 and a second portion 30 extending towards base 28. In the present example, the second portion 30 of each support element 20 defines first and second leg-like protrusions, referenced 33 and 35 respectively. The cam member 24 is mounted, via a threaded bore 31 (FIG. 1B), onto a drive screw 32 rotatable about a fixed axis 34 extending through a lower portion of the container and oriented transversely to the pivot members 22. Rotation of a knob or handle 36 (FIG. 1B) mounted externally of the container, causes rotation of drive screw 32 via first and second gear wheels 38 and 40. As cam member 24 has a bottom surface 42 which engages bottom surface 44 of the container, the rotational motion of the drive screw 32 causes a linear translation of cam member 24 along axis 34. As shown in FIG. 1B, cam member 24 defines a single cam portion 46 which is operative to engage either of respective first or second protrusions 33 and 35 of downwardly extending portion 30 of an adjacent support element. Referring now to FIGS. 3A-3C, the operation of the apparatus of FIGS. 1A and 1B is described. As cam member 24 is moved in the direction indicated by arrow 48, cam portion 46 is brought into engagement with second protrusion 35 so as to cause the entire associated support element 20 to rotate about pivot axis 23. The object 14 hitherto supported by support element 20 in a first portion is, therefore, also rotated and comes to rest on an adjacent support element in a first portion 13. According to a preferred embodiment of the invention, cam portion 46 has a pair of sloped surfaces 50 (FIG. 1B) which terminate in a rounded peak 52. It will be appreciated that this reduces the possibility of the cam member 24 becoming jammed with a portion of a support element 20 in an intermediate position. Alternatively, or in addition, either one of protrusions 33 and 35 may be weighted, so as to impart an inherent instability to the support element. Referring once again to FIGS. 1B and 2, as the first and second protrusions 33 and 35 lie along coplanar axes 33" and 35" (FIG. 2), in order to permit adequate clearance between facing first and second protrusions 33 and 35 of adjacent support elements 20, the spacing S 1 (FIG. 1B) between adjacent pivot axes 23 must slightly greater than the combined width W 1 of first and second protrusions 33 and 35. Reference is now made briefly to FIGS. 4A and 4B, which illustrate apparatus 10 of the invention, but wherein the support elements 54 employed are as shown in FIG. 5. According to the present embodiment, respective first and second protrusions 56 and 58 of support elements 54 are staggered along the pivot axis 23, such that protrusions 56 and 58 lie along non-coplanar axes 56" and 58" (FIG. 5). In order to permit adequate clearance between facing first and second protrusions 56 and 58 of adjacent support elements 54, the spacing S 2 (FIG. 4B) between adjacent pivot axes 23 is required to be slightly greater than the width W 2 of only a single one of first and second protrusions 33 and 35 plus the thickness of pivot member 22. It will be appreciated, therefore, that a larger number of support elements may be mounted, and consequently, a larger number of objects may be stored, in a container 12 constructed according to the present embodiment, than according to the embodiment of FIGS. 1A-2. In addition, whereas the maximum length of first and second protrusions 33 and 35 (FIGS. 1B and 2) is equal to half of the spacing between adjacent pivot members 22, the described staggering of the protrusions 56 and 58 (FIGS. 4B and 5) permits their length to be equal to the entire spacing between adjacent pivot members, such that for spacing S 2 =S 1 , the protrusions 56 and 58 may be approximately twice the length of protrusions 33 and 35 and constitute, therefore, lever arms twice the length of their non-staggered counterparts. Accordingly, the rotation apparatus 16 constructed according to the present embodiment, employing staggered protrusions, allows for less accurate dimensions than are required with the embodiment of FIGS. 1A-2. FIG. 6 illustrates storage and display apparatus similar to that shown and described above in conjunction with FIGS. 1A, 1B, 4A and 4B, but employing a cam member 60 that is movable along axis 62 via a drive belt 68 to which it is attached and which forms part of a pulley system 64. A desired direction of movement of cam member 60 is achieved by rotation of handle 36 mounted externally of the container, which causes rotation of pulley wheel 66 via first and second cooperating helical gears 39 and 41, so as to drive the belt 68. Pulley wheel 66 is mounted coaxially with helical gear 41 about an axis 70 which is perpendicular to axis 62. Reference is now made to FIG. 7, which illustrates storage and display apparatus similar to that shown and described above in conjunction with FIGS. 1A and 1B, but, in place of the drive screw 32 and the cam member 24, the present embodiment employs an elongate, axially rotatable rod member 72, having a helical cam element 74. Helical cam element 74 undergoes a rotation of 360° along the length of the container 12. Accordingly, as the rod member 72 is axially rotated, respective predetermined portions of the helical cam member 74 are rotated upwards, (as seen in the orientation of the apparatus illustrated in FIG. 7) so as to engage a predetermined protrusion of each corresponding support element 20. This is shown particularly clearly in FIG. 8, in which a hatched portion 74" of the helical cam member 74 is shown to be engaging a first protrusion 33 of support element 20. As rod member 72 is rotated in the direction indicated by arrow 78, portion 74" undergoes a motion having, inter alia, an upward component, indicated by arrow 80, so as to engage an edge portion 76 of first protrusion 33 of the support element 20. As rod member 72 is rotated further, the first protrusion 33 of the support element 20 is rotated as indicated by arrow 82 (also shown in FIG. 7). Accordingly, the entire support element 20 is rotated about its pivot axis 23. Reference is now made to FIG. 9, which illustrates storage and display apparatus having a container 12 and support elements 20 as shown and described above in conjunction with FIGS. 1A and 1B, but wherein there is provided a cam member 78 mounted for movement along its longitudinal axis 80 and having a plurality of differently spaced cam portions 82a, 82b, 82c, 82d, . . . According to the illustrated embodiment, the plurality of support elements 20 are distributed at a pitch `p` as measured parallel to axis 80, and the cam portions 82a-82d are spaced at uniformly increasing intervals so that first protrusions 33 of adjacent support elements 20a, 20b, 20c and 20d are successively engaged by their corresponding cam portions 82a-82d. For purposes of clarity, the pivot members 22 are indicated on the drawing as 22a, 22b, 22c and 22d, and are illustrated as defining respective pivot axes 23a, 23b, 23c and 23d. According to the present embodiment, when the first cam portion 82a is in alignment with pivot axis 23a, along axis 80, cam portion 82a is spaced from its corresponding pivot member axis 22b by a distance d; cam portion 82c is spaced from its corresponding pivot member axis 22c by a distance 2d; and cam portion 82d is spaced from its corresponding pivot axis 22d by a distance 3d, where d=P/N, N being the total number of support elements. It will thus be appreciated that when there are N support elements 20 arranged at a pitch P, the spacing between the nth cam portion and the (n-1)th cam portion equals: P-[d×(N-1)]. Quality d is typically very small, and in order to permit satisfactory operation of the present embodiment of the invention, there is provided, in the present example, a knob or handle 86 having a radius that is relatively large when compared to d. Knob 86 is operative to rotate 360° turn helical cam 88 about an axis 90. The helical cam is operative to engage an end groove defined 91 defined by elongate cam member 78 so as to move it in a selected axial direction and so as to provide successive rotation of support elements 20. As shown, the end 92 of cam member 78 is spaced from an adjacent wall portion 93 of container 12 by a distance equal to at least P. Reference is now made briefly to FIG. 10, in which there is illustrated an embodiment of the invention similar to that of FIGS. 1A and 1B, but employing support elements 94, which have a different configuration to that of support elements 20 of the embodiment of FIGS. 1A and 1B. According to the present embodiment, each support element 94 has a planar protrusion 96 extending towards base 28 of the container and a larger planar portion 98 extending away from base 28. Typically, protrusion 96 and portion 98 are coplanar. A further difference between the present embodiment and that of FIGS. 1A and 1B, is that in the present embodiment, a cam member 97 is employed in place of cam member 24 (FIG. 1B). As illustrated, cam member 97 includes an upper cam portion 99 of a flexible construction. Portion 99 may, for example, be a leaf spring. This flexibility is required so as to permit passage of the cam member past protrusion 96 of a support element 94 which are required to be overlapping at all times so as to enable mutual engagement when the cam member is travelling in either direction along axis 34. Alternatively, protrusions 96 may have a flexible construction while the cam member has a construction similar to that of cam member 24 (FIG. 1B). Referring now to FIG. 11, there is shown a storage and display system similar to that illustrated in FIG. 10, but wherein a magnetic displacement member 100 is provided, and protrusions 96 of support elements 94 are made of a magnetic material, typically a ferromagnetic material. As magnetic member 100 is displaced along axis 34, it exerts a magnetic force on a corresponding support element 94, via its magnetic protrusion 96, so as to cause rotation of the support element about its pivot axis 23, thereby causing a similar rotation of an object 14 supported thereby. A particular advantage of the illustrated embodiment is that as it employs a non-contact method of rotationally engaging the support elements, there is a reduced risk of jamming occurring between a support element and the displacement (cam) member. Referring generally now to FIG. 12, there is illustrated storage and display apparatus 110 for flat objects, constructed in accordance with yet further embodiments of the invention. Apparatus 110 employs a container 112, in association with which is mounted gas jet apparatus 114 for successively rotating each of the objects 14 between first and second relatively inclined positions, shown generally at 113 and 115 respectively, so as to display a selected surface 18 of each object. As described above in conjunction with the embodiment of FIGS. 1A and 1B, the rotation of each stored object 14 causes virtually the entire surface 18 of each object to be displayed. According to the illustrated embodiment apparatus 110 includes a plurality of spaced apart support elements 120 mounted onto a plurality of parallel pivot members 122 defining pivot axes 123 and mounted onto a mounting member 125. Each support element 120 is configured to support a single object 14 in either of the first or second positions, and may be rotated about its pivot axis 123 by the rotation of an object 14 supported to the rear of the support element 120. Rotation of the supported object is achieved by application thereto of a high pressure jet of gas provided by gas jet apparatus 114. In the illustrated embodiment, the gas jet apparatus includes a nozzle 124, mounted for free rotation about an axis 126 extending through a carriage member 128. The carriage member 128 is mounted, via a threaded bore (not shown) onto a drive screw 132 rotatable about a fixed axis 134 extending through an upper portion of the container and oriented transversely to the pivot axes 123. Rotation of a knob or handle 136 mounted externally of the container, causes rotation of drive screw 132 via first and second gear wheels 138 and 140. Typically, carriage member 128 is prevented from rotation about axis 134 by means of a surface (not shown) arranged for sliding travel along a side portion 142 of the container. Accordingly, rotation of the drive screw 132 causes a linear translation of carriage member 128 along axis 134. As carriage member 128 is moved, for example, in the direction indicated by arrow 143, gas nozzle 124 engages an edge of one of the stored objects, referenced 14', and is thus pivoted about axis 126. Once the gas nozzle is rotated to a predetermined angle, a high pressure jet 127 of gas is provided so as to exert a force on the object immediately in front, referenced 14", so as to cause its rotation from first inclined position 113 to second inclined position 115. As the object 14" is thus rotated, it rotatably engages the support element 120' immediately in front of it. Typically, although not necessarily, the gas used is filtered air provided from a source 121, which may be, for example, any suitable light duty compressor known in the art. According to an alternative embodiment, however, support elements 120 are not provided, and each object 14 rests on an adjacent object and, when rotated, therefore, its rotation between the first and second positions is unobstructed. FIG. 13 illustrates storage and display apparatus similar to that shown in FIG. 12, but wherein the gas jet apparatus, referenced generally 144, includes a gas jet nozzle 145 mounted onto a carriage 146 is configured to slide freely along drive screw 132. Carriage 146 is drawn along the drive screw 132 by an internally threaded, generally C-shaped leader 148. Leader 148 is typically mounted between the drive screw 132 and portion 142 of the container. Alternatively, portion 142 may be replaced by a track member (not shown) parallel to the drive screw and extending along the length of the container. Carriage 146 and leader 148 are connected via an articulated connection 150, so as to enable movement of the gas jet apparatus in either direction along the axis 134. In contrast to the embodiment of FIG. 12, gas nozzle 145 is not brought into touching engagement with the stored objects 14, but is instead inclined, according to the direction of travel, in either of two predetermined positions 152 and 154 defined by stop members 156 and 158 formed on carriage 146. The gas nozzle 145 provides a gas of jet so as to rotationally displace an engaged object 14 as described above in conjunction with the embodiment of FIG. 12. In the position illustrated, gas jet apparatus 144 is being displaced along axis 134 towards a first end 160 of drive screw 132. To reverse the direction of movement of the apparatus 144 such that it travels towards a second end 161 of the drive screw, the direction of rotation of drive screw 132 is reversed. As illustrated in FIGS. 14A-14D, as the direction of movement of leader 148 is reversed, as indicated by arrow 162 (FIG. 14A), leader 148 moves towards carriage 146 while gas nozzle 145 is rotated clockwise (in the illustration) about axis 147 until leader 148 passes the carriage 146 and eventually takes up the position shown in FIG. 14D. At this position, further rotation of gas nozzle 145 is prevented by stop members 156 and 158 and so uniform movement of the entire gas jet apparatus 144 towards the second end 161 of drive screw 132 may commence. As with the embodiment of FIG. 12, the present embodiment also, does not necessarily include support elements 120 and each object 14 rests on an adjacent object and, when rotated, therefore, its rotation between the first and second positions is unobstructed. It will be appreciated by persons skilled in the art that the scope of the present invention is not limited to what has been specifically shown and described hereinabove by way of example. The scope of the present invention is limited, rather, solely by the claims, which follow.

A storage container for a plurality of flat objects is disclosed. The container has apparatus for successively displaying a surface portion of each stored object so as to enable rapid visual scanning. The apparatus rotates successive objects from a first display position to a second position which displays the next successive object.

RELATED APPLICATIONS [0001] This application claims priority from German Application No. DE 10 2009 039 669.1, filed Sep. 2, 2009, which is herein incorporated by reference in its entirety for all purposes. FIELD OF INVENTION [0002] The present invention relates to a hand gun with a tensioning lever (cocking lever), connected with the lock, which lever has at least one handle for cocking the weapon. BACKGROUND OF THE INVENTION [0003] A self-loading hand gun is a firearm or weapon known from the prior art, in which the tensioning lever is securely connected with the lock. A hand gun of the type named in the introduction is described for example in DE 10 2006 006 034 B. There, the handle, connected with the tensioning lever, is arranged at the rear end of the housing of the weapon. The tensioning lever has a T-shaped hand grip there, which projects out from the housing and on which two handles are arranged on both sides of the weapon. Cocking takes place by drawing back the tensioning lever in the longitudinal direction of the weapon. The T-shaped hand grip has the advantage that the tensioning lever can be operated both by a right-handed person and also by a left-handed person. However, in this known solution, the relative position of the tensioning lever in relation to the housing of the weapon is established at its rear end. SUMMARY OF THE INVENTION [0004] An object of the present invention consists in providing a hand gun of the type named in the introduction, which is designed such that the relative position of the handle for actuating the tensioning lever is changeable on the weapon. [0005] The solution to this problem is provided by a hand gun of the type named in the introduction, having the characterizing features of the claims. [0006] According to one aspect of the invention, provision is made that, viewed in the longitudinal direction of the weapon, at least two alternative fastening positions, spaced apart from each other, are provided for the handle for actuating the tensioning lever. [0007] Preferably, at least three fastening positions, respectively spaced apart from each other in the longitudinal direction of the housing, are provided along the housing for the handle for actuating the tensioning lever. The user therefore has the possibility of selecting the position of the handle for actuating the tensioning lever as required, as appears to him to be the most comfortable and the most favourable when handling the weapon. [0008] In addition, according to one embodiment of the present invention, provision is made that both on the right-hand side and also on the left-hand side of the housing, at least respectively one fastening position, preferably at least respectively two alternative fastening positions, respectively spaced apart from each other in the longitudinal direction of the housing, are arranged for the handle for actuating the tensioning lever. Through this measure, it is possible to produce a weapon which can be used uniformly both by right-handed people and also by left-handed people. This is particularly advantageous for logistics in the military field, because then two different models do not have to be stored for one weapon type. Preferably, the rearmost fastening position here is situated with some distance in front of the rearmost end of the weapon and the further fastening positions lie further towards the front. [0009] It is also possible to provide a handle for actuating the tensioning lever respectively both on the right hand side and also on the left hand side of the housing (bi-manual handle), so that in this case it is even possible that selectively a left-handed person or a right-handed person uses the weapon, without it first being necessary to release the handle from its position and mount it on the other side of the weapon. [0010] According to another embodiment of the invention, the handle for actuating the tensioning lever is releasable by releasing a screw connection out of its respective fastening position. It is therefore very simple to alter the respective fastening position of the handle. The latter can be fastened for example so that it can be unscrewed without a tool, by hand out from its fastening position and screwed in, in another position. For example, at its end facing the weapon, the handle has a thread which is associated with a corresponding thread in the tensioning lever. The latter thread can lie for example inside the housing in the region of the groove, so that when the handle is fastened it is not visible from the exterior. The handle can, for example, be a kind of pin which projects on the housing, protruding laterally outwards from the groove. [0011] Yet another embodiment of the invention provides that a groove, open towards the exterior, on the housing of the hand gun is associated with at least one fastening position of the handle, into which groove the handle partially engages radially. [0012] An element of the handle and/or a connecting element to the tensioning lever may be guided in the above-mentioned groove in a longitudinal direction during the cocking motion or movement for cocking of the hand gun in preparation for discharging a round. [0013] In addition, a groove, open towards the exterior, on the housing of the weapon may be associated with each fastening position of the handle, into which groove the handle partially engages radially (in transverse direction) and the length of this groove, in which the handle may be guided in a movable manner, corresponds respectively approximately to the cocking path of the tensioning lever. [0014] An element, projecting outwards out of the groove, which is connected with the tensioning lever or which is a part of the tensioning lever, may form the handle for its actuation and may be constructed for example for instance in the manner of a knob or button. This element can, for example, be connected with a shaft which projects in radial direction into the groove and is guided in the latter. [0015] Other features identified in the claims relate to additional aspects of the invention. Further advantages of the invention will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0016] The present invention is described in further detail below with the aid of example embodiments with reference to the attached drawings, in which: [0017] FIG. 1 shows a perspective view of a self-loading pistol according to the present invention with a handle for actuating the tensioning lever; [0018] FIG. 2 shows a vertical section through the weapon of FIG. 1 ; [0019] FIGS. 3 a - 3 d show four diagrammatically simplified illustrations respectively as a side view, which show a handle according to the invention in various positions on the tensioning lever; [0020] FIGS. 4 a - 4 c show three diagrammatically simplified sectional illustrations which explain the principle of fastening the handle according to the invention. DETAILED DESCRIPTION [0021] Firstly, reference is made to FIG. 1 . The illustration shows a self-loading piston 10 , in principle of conventional type of construction with a grip piece 11 , a housing 12 and a lock arranged slidingly with respect to the housing in the shooting direction. A tensioning lever (cocking lever), which is connected with a handle 15 , is connected with the locking system. For cocking, the tensioning lever is moved contrary to the shooting direction towards the rear end of the weapon. Several spaced grooves 16 are preferably situated respectively on each side of the weapon, wherein the handle 15 is associated at least with one of these grooves 16 a . In FIG. 1 of the drawings, the handle is situated in the rearmost groove 16 a on the left hand side of the weapon in the position of rest, in which it is situated as is seen at the front end of the groove 16 a . For cocking the weapon, one grips on the handle 15 and by means thereof draws the tensioning lever and hence the lock towards the rear. [0022] FIG. 2 shows a diagrammatic vertical section through the weapon of FIG. 1 , wherein the handle 15 can be seen, projecting into the groove of the housing and aligned in transverse direction, which is securely connected in the mounted position with the tensioning lever extending in longitudinal direction in the housing. The handle 15 is, however, releasable from the tensioning lever for example after releasing of a screw connection, and can also be connected therewith in an alternative position (relative to the weapon). [0023] Further details in this respect are apparent from the diagrammatic illustrations of FIGS. 3 a to 3 d and 4 a to 4 c . In FIGS. 3 a to 3 d , the tensioning lever 14 is illustrated diagrammatically, wherein the housing of the weapon is not shown. In the various illustrations of FIGS. 3 a to 3 d , the handle 15 is situated in respectively different positions on the tensioning lever 14 . The tensioning lever 14 has a connecting element 13 for connection with the locking system, which is not illustrated here. In addition, several threaded bores 17 are seen in spaced positions laterally on the tensioning lever 14 . The handle 15 is provided at its end facing the tensioning lever 14 with a corresponding threaded piece, so that the handle can be selectively screwed into one of the threaded bores 17 and fastened there. On drawing back, the tensioning lever 14 is moved towards the rear against the force of a diagrammatically indicated spring 18 . [0024] In FIG. 3 b a variant is illustrated, in which two handles 15 a and 15 b are arranged on the tensioning lever 14 at the same height and in positions lying opposite each other, so that they are situated on the right hand side and on the left hand side of the weapon and permit an operation by right-handed people or left-handed people. [0025] FIG. 3 c shows a variant in which the handle 15 is again situated in the rearmost position, but here on the right hand side of the weapon. In FIG. 3 d , the handle was fastened in a position lying further towards the front and it is indicated by the arrows that the handle is releasable from its position on the tensioning lever respectively by unscrewing and is able to be fastened in another position. [0026] Further details are apparent from the diagrammatic sectional illustrations of FIGS. 4 a to 4 c . FIG. 4 a shows here a position corresponding in principle to FIG. 3 a , in which the handle 15 is situated on the left on the tensioning lever. In this sectional illustration, a thread 19 can also be seen in a threaded bore of the tensioning lever 14 . In this example embodiment, the handle 15 is a type of pin, which narrows on the end side and has a thread there, which engages into the internal thread 19 in the threaded bore (transverse bore) of the tensioning lever 14 . The handle therefore extends transversely to the tensioning lever and to the longitudinal extent (shooting direction) of the housing of the weapon. As FIG. 2 shows, the handle can also be slightly thickened on the outer side and can be constructed for example approximately in the manner of a knob. [0027] FIG. 4 b shows the variant of FIG. 3 b in section with handles 15 a , 15 b arranged on both sides on the tensioning lever 14 . FIG. 4 c shows the variant of FIG. 3 c , in which only a handle 15 b is arranged on the right hand side of the tensioning lever 14 . [0028] Referring to the figures and the list of reference numbers generally, the invention is susceptible of other and various embodiments. For example, there is a hand gun with a tensioning lever (cocking lever), connected with the lock, which has at least one handle for cocking the weapon, characterized in that viewed in the longitudinal direction of the housing ( 1 ), at least two alternative fastening positions, spaced apart from each other, are provided for the handle ( 15 ) for actuating the tensioning lever ( 14 ). [0029] The hand gun may be further characterized in that along the housing at least three fastening positions, respectively spaced apart from each other in the longitudinal direction of the housing, are provided for the handle ( 15 ) for actuating the tensioning lever ( 14 ). [0030] The hand gun may characterized in that both on the right hand side and also on the left hand side of the housing, respectively at least one fastening position, preferably at least respectively two alternative fastening positions, respectively spaced apart from each other in the longitudinal direction of the housing, are arranged for the handle ( 15 a , 15 b ) for actuating the tensioning lever ( 14 ). [0031] The hand gun may also be characterized in that the handle ( 15 ) to actuate the tensioning lever ( 14 ) is releasable from its respective fastening position by releasing a screw connection. [0032] The hand gun may also be characterized in that a groove ( 16 ), open towards the exterior, on the housing ( 12 ) of the weapon is associated with at least one fastening position of the handle ( 15 ), into which groove the handle partially engages radially. [0033] The hand gun may also be characterized in that an element of the handle ( 15 ) and/or a connecting element to the tensioning lever ( 14 ) is guided in a groove ( 16 ) in the longitudinal direction on the movement for cocking. [0034] The hand gun may also be characterized in that a groove ( 16 ), open towards the exterior, on the housing of the weapon is respectively associated with each fastening position of the handle ( 15 ), into which groove the handle ( 15 ) partially engages radially (in transverse direction) and the length of this groove corresponds respectively approximately to the cocking path of the tensioning lever ( 14 ). [0035] The hand gun may also be characterized in that an element, projecting towards the exterior out from the groove ( 16 ), which is connected with the tensioning lever ( 14 ) or which is a part of the tensioning lever, forms the handle ( 15 ) for its actuation and is constructed for instance in the manner of a pin, a knob or a button. [0036] The hand gun may be further characterized in that the element ( 15 ) is connected with a shaft, which projects in radial direction (transverse direction) into the groove ( 16 ) and is guided in the latter. [0037] The following is a listing of reference numbers and associated components of illustrated embodiments: 10 —firearm 11 —grip piece 12 —housing 13 —connecting element 14 —tensioning lever 15 —handle 15 a —handle 15 b —handle 16 —grooves 16 a —groove 17 —threaded bores 18 —spring 19 —thread

The present invention relates to a hand gun with a tensioning lever (cocking lever), connected with the lock, with a handle for cocking the weapon, for which at least two alternative fastening positions are provided for the handle for actuating the tensioning lever. The relative position of the handle for actuating the tensioning lever is changeable on the weapon, so that one can engage for cocking in various positions on either the right hand or left hand side, so that the tensioning lever can be adjusted to fit and be operated by a right-handed or a left-handed person.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gelled diethylene glycol to be used as a heat source or fuel. More particularly, this invention relates to a composition of matter consisting essentially of diethylene glycol and a fumed silica product. 2. Description of the Prior Art Portable heat sources have been used for many years including, campers and military personnel. To avoid the bulk and impracticality of liquid sources inherent in camp stoves, a number of devices have been invented to provide a source of fuel in a gelled or colloidal form. One such device is a gelled alcohol marketed as STERNO. Because of its volatile characteristics inherent in alcoholic compositions, this device suffers from several limitations and disadvantages. First, when ignited, the heat degenerates the gel to a liquid form, which may spread a fire rapidly if spilled. Further, due to its volatile nature, it emits fumes and a considerable odor when burned which are harmful to the health of those in close proximity. Another gelled heat source is disclosed and defined in U.S. Pat. No. 4,302,208. This invention relates to a fuel for fuel air explosive devices for military uses and its composition consists of a polar fuel, silicon dioxide and a mixture of two alcohols. One of the alcohol compositions contains an ether linkage, with volatile characteristics with such limitations as described above. Another fuel source is disclosed and defined in U.S. Pat. No. 4,756,719. This invention relates to a composition consisting of a combustible polymer, an organic solvent and a course powder of fiber material. The disadvantage and limitations inherent in organic based fuels are its tendencies to evaporate quickly and emit fumes and odors which may be poisonous or noxious. It is therefore, an object of the present invention to provide a small efficient gelled fuel heat source primarily for field use in heating food and which is neither poisonous or noxious and which does not evaporate quickly. It is a further object of the present invention to provide a fuel source which maintains its high degree of viscosity over a long shelf life and during turbulent handling and shipping conditions. The present invention represents an improved and novel composition. It is characterized by a number of advantages which increases its utility over prior art heat sources. These and other objects and advantages of the present invention will become evident from the following disclosure to those skilled in the art to which this invention pertains. SUMMARY OF THE INVENTION The preferred embodiment of the present invention relates to a gelled fuel heat source consisting of diethylene glycol and a fumed silicon product. Use of diethylene glycol as a fuel source has many advantages over the prior art such as alcohol and organic based fuel sources. Diethylene glycol burns clearly without fumes or odor. When mixed with a fumed silica product as a gelling agent, a gel forms with a high degree of viscosity capable of being packaged in an envelope, can, or tube. Addition of the fumed silica product produces good wicking characteristics with a high flash point. Further, the diethylene glycol contributes a high caloric value to the gel which requires only a small portion for each use. The composition may be used directly a field use includes fuel for heating food or as a starter for igniting firewood. This is a mechanical means for gelling, however, several chemical means have also been found to produce desirable results. One chemical means for gelling or solidifying the diethylene glycol was to react the diethylene glycol with stearic acid. When 5 percent to 40 percent by weight of stearic acid is heated with the diethylene glycol until dissolved, upon cooling, a wax-like candle is formed. Because the material is semi-solid, a conventional wick can be used to ignite the material. If I to 5% of fumed silica is added to the total mixture, sufficient wicking is provided by the silica alone. One added feature of this mixture, if reacted long enough, is that the material can be used as a soap in addition to being a fuel source. A second means of chemically gelling or solidifying diethylene glycol is to react it with 10 percent to 40 percent by weight of polyethylene glycol. This mixture must also be heated to dissolve the polyethylene glycol. If 1 percent to 5 percent by weight of fumed silica is added for wicking, an easily ignitable mixture can be prepared which burns with a pale blue flame, that is very difficult to extinguish. Another means of chemically gelling diethylene glycol is to react it with 10 percent to 40 percent by weight of polyvinyl alcohol. When heated to 200° F to 300° F and cooled to room temperature, the mixture forms a rubbery semi-solid material. While burning it melts like a wax candle. DESCRIPTION OF THE PREFERRED EMBODIMENT The composition of this invention is made up by mixing diethylene glycol and a fumed silica product. This very fine silica product increases the viscosity of the diethylene glycol from a liquid to a gelled form. Such silica products are commercially available under the trade names CAB-0-SIL and AEROSIL. Even though the vapor pressure is very low for diethylene glycol, the fumed silica acts like a wick for the mixture and can be easily ignited with a match. The product when heated does not melt or soften but remains in its semi-solid condition. It burns clean with no smoke or odor and leaves only the silica residue. It has been discovered that while this composition has desirable viscous characteristics upon formulation, it has a tendency to become less viscous with severe agitation. A trace quantity of a caustic compound when added to the aforementioned composition will stabilize the viscous characteristics of the gelled mixture. Examples of caustic compounds suitable for use include sodium hydroxide, potassium hydroxide, and calcium oxide. Tests have disclosed that traces of a caustic compound in the range of about 0.05 to 0.5 percent by weight is sufficient to retain the gel's viscous characteristics. The preferred weight percentages for the composition consists of 5 to 25 percent of fumed silica, 75 to 95 percent diethylene glycol and 0.05 to 0.5 percent of a caustic compound. In an alternative composition, fly ash may be used to replace some of the more expensive fumed silica in a range of I0 to 40 percent by weight. This substitution may result in more than a 50 percent formulation cost savings using a mix by weight of fly ash of 40 percent and a 2 percent mix by weight of fumed silica. Additionally, the fly ash provides the caustic characteristics which retains the viscous quality of the gelled composition. The composition may be packaged with military field rations where a simple envelop would be used to heat water for soup and coffee. The tubes will also find ready application among the military, scouters, and campers. The canned material can be used. The compositions of the present invention when prepared according to the ranges of weight percentages set forth above, may be packaged in a variety of manners. For single use applications, the gel may be packaged in envelopes of aluminum foil, plastics, or plastic lined paper. For multiple use applications, the gel may be packaged in plastic or foil tubes (like toothpaste), and the desired amount can be squeezed out and ignited. Additionally, the gel may also be packaged in metal cans of various shapes.

A stable gelled material used as a fuel which consists of a composition of diethylene glycol mixed with a gelling agent of fumed silica. Polyethylene glycol may also be added to improve its burning characteristics.

BACKGROUND OF THE INVENTION The invention relates to a shiftable friction clutch and to a method for producing a shiftable friction clutch. Shiftable friction clutches actuated by a flowable pressure medium are known in various embodiments, in particular from vehicle technology. Such shiftable friction clutches are sometimes used to couple fans or cooling or lubrication pumps in a shiftable manner to the engine shaft. Clutches of this kind must, on the one hand, operate very reliably and, on the other, must be built as compactly is possible. In this regard the accommodation of a working chamber for a pressure medium, which should be as fluid-tight as possible, presents a particular design challenge. In addition, a resilient element which counteracts the expansion of the pressure medium must be accommodated within such a shifting device, which has a number of reciprocally moving parts. SUMMARY OF THE INVENTION It is the object of the invention to provide a clutch which has a comparatively simple and space-saving structure. This object is achieved by a shiftable friction clutch with the features described herein. Advantageous and useful developments of the invention are also specified. The invention is based on a shiftable friction clutch for actuation with a flowable pressure medium, which includes two coupling elements which are mounted rotatably about the same axis and are able to be brought into frictional contact with one another in order to transmit a rotary motion, and a pressure chamber located in the clutch, the volume of which is variable by means of an axially movable piston, the piston being held in a predefined position by the force of a spring. The pressure chamber serves to receive a flowable pressure medium with which the piston can be displaced by a pressure increase against the force of the spring, and the clutch can thereby be either engaged or disengaged. The spring is a disk spring. Especially as a result of their shallow construction, disk springs offer the advantage that they require comparatively little space in the axial direction of the axis of rotation of the clutch. In particular, annular disk springs, with their concentrically arranged edges, the inner or outer of which edges can be firmly clamped, are especially well adapted to the geometry of a clutch. Given the predefined shape of the disk spring, further parameters may be selected, such as material, material thickness and incisions in the spring surface with which both the spring rate and the spring travel can be adjusted. As a result, a clutch according to the invention can advantageously be adapted to different requirements with slight changes, or no changes, to its dimensions. Because planar resilient sections, or a plurality of resilient sections connected in parallel, contribute to the spring effect of disk springs, the springs offer greater reliability and lower susceptibility to failure in comparison to spiral springs, for example. The spring is mounted inside the pressure chamber. This has the advantage that no separate location needs to be provided for installing the resilient element of the clutch. In addition, the spring travel lies within the expansion space of the pressure medium, in which the piston is easily accessible for cooperation with a spring. By accommodating the spring, in particular the disk spring, within the pressure chamber, an inventive shiftable friction clutch implemented in this way offers the advantage of an especially compact construction. The essence of the invention is that the disk spring pulls an outer coupling element towards an inner coupling element, so that conical friction surfaces come into frictional contact with one another. A shiftable friction clutch according to the invention advantageously has a mechanical stop configured in such a manner that the mechanical stop limits an axial displacement of the piston brought about by the flowable pressure medium to a predefined maximum volume of the pressure chamber which receives the pressure medium. Such a mechanical stop restricts the spring travel, and therefore advantageously prevents possible excessive elongation of the disk spring. In particular, if the mechanical stop arrests the displacement of the piston at a comparatively large distance from the axis of rotation of the clutch and symmetrically thereto, the mechanical stop can stabilize the position of the piston when under pressure. The mechanical stop can thereby advantageously reduce out-of-balance mass during operation of the clutch. A preferred configuration of the invention provides that the surfaces of the coupling elements which are able to come into frictional contact with one another in order to transmit a rotary motion have a conical configuration with respect to the axis of rotation. With conical friction surfaces, as compared to flat friction surfaces disposed perpendicularly to the axis of rotation of the clutch, the height of the shiftable friction clutch along the axis of rotation of the clutch can advantageously be utilized to increase the surface area involved in the frictional connection. In addition, conical friction surfaces have the advantage that the drive and output elements of the clutch are centered with respect to one another when the clutch is engaged. Because of the conical effect with which the two conical friction surfaces engage in one another, the torque transmission is less susceptible to vibrations and shocks acting perpendicularly to the axis of rotation. It is especially preferred that the surfaces of the coupling elements which are able to come into frictional contact with one another in order to transmit a rotary motion have, when without frictional contact, an axial overlap region with respect to the axis of rotation, viewed radially towards the outside. Such an axial overlap region, in which one coupling element encircles the other, offers advantageous protection against the penetration of contaminants into the interior of the clutch. Furthermore, an axial overlap region ensures that the clutch can be securely engaged even with out-of-balance forces acting on at least one coupling element, for example as a result of bearing damage. A preferred configuration of the invention provides that a transmission of torque takes place at the friction surfaces if the force exerted on the piston by the pressure medium is smaller than the force of the disk spring by which the friction surfaces are pressed against one another. The clutch can therefore be disengaged only when the pressure medium is pressurized sufficiently strongly. Such a mode of operation offers the advantage that assemblies which must reliably continue to operate remain connected by the clutch even if the pressure medium can no longer be pressurized. A further preferred configuration of the invention is distinguished by the fact that a transmission of torque takes place at the friction surfaces if the force exerted on the piston by the pressure medium is greater than a force of the disk spring by which the friction surfaces are held out of contact. This means that the pressure medium is pressurized only in order to engage the clutch. Such a configuration of the invention has the advantage that auxiliary assemblies in a vehicle, support from which is required only sporadically and usually for short periods, require the clutch to be pressurized only in these periods. In the disengaged state the clutch itself is unpressurized and during this time the auxiliary assembly consumes no mechanical power of the drive, for example of an internal combustion engine. It is further preferred that the coupling elements have permanent magnets in order to transmit a rotary motion, so that transmission of a rotary motion can take place without frictional contact between the coupling elements, on the principle of an eddy current clutch. A rotary motion can thereby advantageously be transmitted even in the disengaged state of the clutch according to the invention. This makes it possible, for example, to drive assemblies such as a fan, which must move throughout an operating time of an engine, although a maximum rotational speed of the mechanically engaged state is required only infrequently. The friction surfaces of the coupling elements preferably consist of steel. Especially if the coupling elements having the friction surfaces are made of steel, the complexity and cost of producing the coupling elements can advantageously be reduced by this configuration of the invention. Moreover, this has the advantage of comparatively low wear of the friction surfaces, especially if only a comparatively small torque is required for driving, for example, a fan wheel in the engine compartment, in the engaged mode. BRIEF DESCRIPTION OF THE DRAWINGS Two exemplary embodiments and the production method of the shiftable friction clutch according to the invention are described with reference to the drawings, further features and advantages of the invention being explained. In the drawings: FIG. 1 shows a schematic section through a shiftable friction clutch according to the invention with fan for a blower of an internal combustion invention of a vehicle; FIG. 2 shows a schematic section through a shiftable friction clutch according to the invention with eddy current drive; and FIG. 3 shows a flow diagram which illustrates the production of the shiftable friction clutch. Where appropriate, the reference numerals are used in a uniform manner in both figures. DETAILED DESCRIPTION FIG. 1 shows a pneumatically actuatable fan clutch 1 a . A fan wheel 22 is fastened with a plurality of fastening screws 21 to an outer coupling element 3 . An inner coupling element 2 is screwed to a cover 11 by means of fastening screws 20 . In this case the threads of the fastening screws 20 project beyond the cover 11 , so that this part of the clutch 1 can be screwed to a drive element, for example a belt pulley. A rotary leadthrough 14 conducts a pressure medium line 13 through the cover 11 . Together with a piston 5 , the inner coupling element 2 and the cover 11 form a pressure chamber 4 . The pressure chamber 4 receives compressed air which is supplied via the line 13 . Inside the pressure chamber 4 a disk spring 6 is clamped by its outer edge between the cover 11 and the inner coupling element 2 . At its inner edge the annular disk spring 6 is clamped between the piston 5 and a spring securing plate 16 , which in turn is screwed to a bearing pin 17 . The outer coupling element 3 is mounted rotatably about the axis of rotation of the clutch by means of a ball bearing 18 . The disk spring 6 pulls the outer coupling element 3 towards the inner coupling element 2 via the spring securing plate 16 , the bearing pin 17 and the ball bearing 18 , so that the conical friction surfaces 8 and 9 come into frictional contact with one another. Without excess pressure in the pressure chamber 4 , therefore, the clutch 1 is in the engaged state brought about by the disk spring 6 . By supplying compressed air via the line 13 and the rotary leadthrough 14 , the pressure in the pressure chamber 4 is increased and the piston 5 is displaced against the force of the spring 6 . As this happens, the friction surfaces 8 and 9 of the inner 2 and outer 3 coupling elements are separated from one another. Through the loss of the mechanical frictional contact at the friction surfaces, only a significantly reduced torque can now be transmitted via the friction in the ball bearing 18 . As a result, the fan wheel 22 is set in motion only very slowly, or not at all, with respect to a drive element. The piston travel is limited by the stop 7 . The latter stabilizes the piston 5 and therefore the position of the bearing pin 17 , of the ball bearing 18 and finally of the outer coupling element 3 . The forces exerted on the piston 5 by these clutch parts are therefore absorbed not only by the cylindrical walls of the piston 5 and of the pressure chamber 4 . This has the advantage that both the piston 5 and the pressure chamber 4 can be constructed with a comparatively low depth in relation to their diameter. FIG. 2 shows a further configuration of a pneumatically actuatable fan clutch 1 b according to the invention which, however, additionally has an eddy current drive. For this purpose, a ring on which a plurality of permanent magnets 12 are arranged, preferably symmetrically about the axis of rotation, is located on the outer edge of the coupling element 3 . Located opposite the permanent magnets 12 on the coupling element 3 in the axial direction is a ring 19 with cooling fins, which forms the outer edge region of the cover 11 and is connected to the inner coupling element 2 . The cover 11 is produced from a metal with high electrical conductivity, preferably aluminum. The permanent magnets 12 induce eddy currents in the metal conductive material of the cooling fin ring 19 , so that the outer coupling element 3 is entrained in the direction of rotation of the inner coupling element 2 by electromagnetic forces on the principle of an eddy current clutch. If the clutch 1 b is always actuated with a pressure increase which is sufficient to displace the piston 5 against the stop 7 , this configuration of the invention offers the possibility of setting two different rotational speeds of the fan wheel 22 . Because, in this case, the eddy current drive is operated with a constant distance between the permanent magnets 12 and the cooling fin ring 19 , the dimensions of the cooling fin ring 19 can be adjusted comparatively more precisely to a heat dissipation rate appropriate to the application. The electromagnetic force of the eddy current clutch may basically be made adjustable for speed adaptation of the coupling element on which the fan 22 is arranged. The magnetic force may be adjusted by varying one or more of the following options: a) The number of magnets used in the eddy current system; b) The size of the air gap of the eddy current system, that is to say the air gap between a section on the cooling fin ring 19 in which the eddy current zone is formed and the outer coupling element 3 which bears the magnets 12 ; c) The strength of the magnets 12 which are used. In the exemplary embodiment of FIGS. 1 and 2 , a movement distance between the inner coupling element and the outer coupling element 3 between the non-engaged and engaged states may be 1.5 mm when the clutch is new, and may increase up to 3.7 mm, for example, at the end of the clutch service life, without the function of the clutch being impaired. The exemplary embodiment is for example designed for providing a force of the disk spring of 2000 Newtons, as a result of which over 600 Newton meters is still available as a static torque at the end of the service life of the clutch. The static torque in, for example, a new, unworn state of the friction surfaces ( 8 , 9 ) may be approximately 1100 Nm. The maximum shiftable torque is approximately 280 Newton meters. With a lever length of approximately 0.5 meter, the force is then approximately 560 Newtons. The input speed may be approximately 3000 revolutions per minute, wherein a slip speed of the eddy current system in the cold state may be approximately 500-1200 revolutions per minute depending on the fan load. In a new state of the clutch, the pressure in the pressure chamber during the opening of the clutch should be 4-5 bar. The discussed parameters serve merely as an example and may vary, without departing from the subject matter of the application. The transmissible torque of the friction shift clutches 1 a , 1 b is dependent on the friction surface area and on the angle of the conical friction surfaces ( 8 , 9 ). The force of the disk spring 6 may likewise be varied in order to be able to influence the shift behaviour of the shifted and non-shifted clutch, or the transmissible torque in the non-shifted state. It is especially preferred that the surfaces of the coupling elements ( 2 , 3 ) which are able to come into frictional contact with one another in order to transmit a rotary motion have, when without frictional contact, an axial overlap region ( 10 ) with respect to the axis of rotation, viewed radially towards the outside. Such an axial overlap region ( 10 ), in which one coupling element ( 3 ) encircles the other, offers advantageous protection against the penetration of contaminants into the interior of the clutch. Furthermore, an axial overlap region ensures that the clutch can be securely engaged even with out-of balance forces acting on at least one coupling element, for example as a result of bearing damage. FIG. 3 diagrammatically illustrates, in the form of a flow diagram, a method for producing the friction shift clutches 1 a , 1 b. The steps above the dashed line may be used to produce a single-stage clutch 1 a . The additional steps below the dashed line may then be carried out to provide a two-stage clutch 1 b with an eddy current drive. First and second conical metal parts 2 , 3 are firstly produced in step S 302 . In step S 304 , a fan holder section is mounted on an outer surface of the outer coupling element 3 . In step S 306 , the outer coupling element 3 is connected to the piston 5 . In steps S 308 , S 310 , S 312 , S 314 , the disk spring 6 is connected to the inner coupling element 2 and to the piston 5 , and the piston is inserted. In step S 316 , the inner coupling element 2 and the outer coupling element 3 are configured such that they can rotate independently of one another. In steps S 318 and S 320 , the inner coupling element 2 is provided with permanent magnets 12 , and the outer coupling element 3 is provided with the cooling fin ring 19 .

The invention relates to a shiftable friction clutch ( 1 a , 1 b ) for actuation with a pressure medium. Clutches of this type can be used, for example, to drive auxiliary assemblies such as fans ( 22 ) in vehicle construction. An especially compact construction is achieved through the use of a disk spring ( 6 ). A production method is furthermore proposed.

CROSS REFERENCE TO RELATED APPLICATIONS This Patent Application is a non-provisional utility application which claims the benefit under 35 U.S.C. 119(e) from U.S. Provisional Patent Application No. 61/937,208 filed on Feb. 7, 2014, entitled, “DETECTING PERIODICITY IN A STREAM OF EVENTS”, the contents and teachings of which are hereby incorporated by reference in their entirety. BACKGROUND Systems that support online services, such as internet banking, receive many inputs from computer users interacting with an online service. For example, an online banking service that provides a website to account holders may receive many mouse clicks, or web clicks, or key strokes over the course of a single online banking session. Each of the individual clicks or strokes represents a discrete event. There may be a pattern to a sequence of clicks in a single online banking session, and this pattern may reveal information about the source of the clicks. Specifically, a periodic set of clicks may raise concerns that the source of the clicks is a threat, such as a password cracker program. Conventional online support services detect periodicity in a sequence of clicks by using algorithms that seek out equally spaced clicks via direct measurement, or by other means such as Fourier transforms. SUMMARY Unfortunately, there are deficiencies with the above-described conventional online support services. For example, mouse or web clicks are typically received in a noisy environment. Specifically, mouse or web clicks may travel through a noisy network and meet with random delays. Consequently, algorithms that base a determination of periodicity solely on finding equally spaced clicks lack the robustness needed to find periodic behavior in such an environment. In contrast to the above-described conventional transaction servers that lack robustness in detecting periodic click streams in a noisy environment, an improved technique involves assigning a periodicity score in a click stream that is indicative of the confidence that the click stream forms a periodic sequence. Along these lines, a server forms an autocorrelation function from clicks in a click stream that contains a series of spikes at time differences between the receive times of each click. The server then convolves this autocorrelation with a jitter kernel that is representative of the temporal noise distribution in the network environment in which the clicks were received. From this convolution, the server may make an estimate of a period T of the click stream. From further analysis, the server may then assign a periodicity score indicative of the confidence level that the click stream is periodic with period T. Advantageously, the improved techniques may be employed to evaluate periodicity in a sequence of discrete events to robustly determine whether there is an attack occurring, whether there has been a change in a specific routine practice, whether there are patterns in a market activity, or many other situations where the either the presence or absence, or of a change in periodicity of any sequence of discrete events has occurred. With such an arrangement, a sequence of discrete events may be analyzed as to whether or not there is a periodic nature, and a score representing the degree of periodicity may be generated. Knowledge of the periodicity, or lack of periodicity, may be useful in determining the likelihood of an attack being in progress, or for data mining items that may be buried in a noisy data stream. Such a system may provide a more robust determination of periodic threats, or periodic opportunities, than prior art methods. Such an arrangement is more capable of accounting for deviations in periodicity caused by communication variations such as jitter, and thus discovering hidden periodicity. One embodiment of the improved technique is directed to a method of evaluating a likelihood that a sequence of discrete events displays periodic patterns. The method includes receiving a sequence of discrete events over a time period, for example the clicks made by a client accessing a bank website, and forming a window in time encompassing a temporal extent over which the sequence of discrete events was received. The method may also include generating a first autocorrelation function for the sequence of discrete events. The method may also include generating a convolution of the first autocorrelation function using a jitter kernel to form a smoothed autocorrelation function having a set of peaks. The method may include generating a period value of the first autocorrelation function corresponding to a highest peak in the smoothed autocorrelation function, and generating a likelihood that the sequence of discrete events is periodic based upon the set of peaks. Other embodiments of the improved techniques are directed to a computer program product which includes a non-transitory computer readable medium storing a set of instructions that, when carried out by a computer, cause the computer to perform the method of evaluating a likelihood that a sequence of discrete events displays periodic patterns. Another embodiment of the improved techniques is directed to a computing circuit, including a communications interface connected to a network, a memory circuit, a receiving circuit constructed and arranged to evaluate a likelihood that a sequence of discrete events displays periodic patterns. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention. FIG. 1 is a diagram of an electronic apparatus for detecting periodicity. FIG. 2 is a flowchart of steps in a method for detecting periodicity. FIG. 3 is a diagram showing the time of arrival of a sequence of clicks and an autocorrelation of the time differences between the arrival times of each of the clicks. FIG. 4 is a diagram showing a convolution of the autocorrelation with a jitter kernel and the resulting smoothed autocorrelation. FIG. 5 is a diagram showing a convolution of the autocorrelation with a second jitter kernel and the resulting second smoothed autocorrelation. DETAILED DESCRIPTION An improved technique involves assigning a periodicity score in a click stream that is indicative of the confidence that the click stream forms a periodic sequence. Along these lines, a server forms an autocorrelation function from clicks in a click stream that contains a series of spikes at time differences between the receive times of each click. The server then convolves this autocorrelation with a jitter kernel that is representative of the temporal noise distribution in the network environment in which the clicks were received. From this convolution, the server may make an estimate of a period T of the click stream. From further analysis, the server may then assign a periodicity score indicative of the confidence level that the click stream is periodic with period T. The convolution results in a smoothed autocorrelation function having a set of peaks, which provide an estimated period value for a potential pattern. The period is used to estimate a second jitter kernel for another convolution R s ′ and a confidence level. The method improves evaluation of periodicity for discrete events, such as clicks, and provides a confidence score that indicates the likelihood that a series of events contains a periodic sequence. The discrete events may be characterized by virtue of the events originating from a single internet address, or from a single user, or having some other common feature such as using the same protocol. Thus, a specific discrete event may become part of two or more click streams. The improved methods may include receiving a sequence of discrete events, such as mouse clicks. The method may include generating an autocorrelation function of the sequence of discrete events, for example fourteen discrete events, where the autocorrelation function may comprise spikes representing pairwise differences in the time received for each individual discrete event. The autocorrelation function may be an arithmetic sum of all the spikes, and spikes that arrive at the measuring location essentially simultaneously may be treated as multiple spikes or as a single spike of proportionally higher strength. In some situations the autocorrelation function may include the differences in time received for a selected portion of all of the spikes received at the measuring location. The method may include generating a convolution R s between the autocorrelation function and what a jitter kernel to form a smoothed autocorrelation function having a set of peaks. Jitter kernels may be a probability distribution function for a random variable representing a time delay between discrete events in the sequence of discrete events, and may have any of a variety of shapes such as a monotonic function, a Gaussian, a raised cosine window, a Hamming window, a Hanning window, a top hat, or a sin(ωt)/t function. The method may also include generating a period value corresponding to a highest peak in the smoothed autocorrelation function, and generating a likelihood of periodic patterns based upon the set of peaks. In some arrangements, the shape maybe a Gaussian function having a standard deviation that may be varied as desired to be indicative of the noise environment and to obtain the desired result in smoothing the autocorrelation function. This will produce a smoothed autocorrelation function R s of the discrete events that may capture slightly delayed clicks, for example due to delays in transmission path, and show them to be part of a periodic pattern. The calculated score may be calculated for each individual peak. In some arrangements, the method includes calculating a period T using the location of the highest peak and compute a second smoothed autocorrelation function using a second jitter kernel, where the width of the second jitter kernel is scaled using the calculated period T, for example a Gaussian having a standard deviation that is a tenth of the period T. In this case, the method also includes generating a final score over the number of discrete events sampled at multiple times. Each of the click streams is evaluated to determine a relative degree of confidence that the sequence of discrete events in the stream actually does exhibit periodic behavior. The periodicity is evaluated for each individual discrete event based upon a selected number of clicks leading up to that individual click, and a confidence score is determined. The number of clicks evaluated may be any number, for example the fourteen previous clicks, with the preceding clicks being ignored for the calculation. The selected number of clicks in an evaluation period may be adjusted to accommodate streams having a large variation in signal travel time, which may be known as jitter. For example, remote access attempts made by a denial of service attack where the network route may vary in length due to changes in network traffic loads would have a certain amount of signal jitter. The above discussion has focused on examples of the use of periodic behavior for determining the presence of potential security threats, but there are other uses as well. Discrete events of various types may have periodic sequences of signal events, or may occur at periodic times. For example, an employer may run a payroll program at the same time each week, or a vertical password guesser may try a new password guess every ten minutes until success is achieved. Some periodic sequences may be benign, and some may indicate an attack. Even in the case where the periodic activity is benign, deviations from the expected benign periodicity may indicate a problem that may indicate a potential issue that needs additional attention. The examples presented will be applied to a general case where an online business uses an outside vendor to perform the periodicity analysis. The online business could directly analyze the sequence of discrete events in the same computer that received the discrete events, but the information on the time of arrival of the discrete events may be sent to a central location for reasons such as maintaining the bandwidth of the computer handling the business events, or because a central vendor may have computer equipment with greater data handling capability and provide faster analysis results than may be obtained using the online business computer. FIG. 1 is a diagram of an electronic apparatus 100 for evaluating a likelihood that a sequence of discrete events displays periodic patterns. The apparatus 100 includes a computing circuit 102 having a receiving circuit 104 for receiving a sequence of discrete events. The receiving circuit 104 is communicatively connected by bidirectional communications means 106 to a network 108 . The communications means 106 may be a wired, a wireless, an RF, an IR connection, or any of many other well-known communication means. The network 108 may be the internet, an intranet, the cloud, a token ring, or any of many other well-known networking devices. The network 108 is communicatively connected to users 112 , 116 , 120 and 124 by bidirectional communications means 110 , 114 , 118 and 122 respectively. Users 112 , 116 , 120 and 124 may represent a bank 112 , a credit card agency 116 , a retail store 120 , a manufacturer 124 , or any person or organization that has a website or electronic devices that use streams of discrete events, such as clicks or keystrokes. Users may employ the network 108 to send information on the discrete event timing to the computing circuit 102 . As an example, when a bank 112 website receives clicks from a customer using a remote terminal, the bank may want to know if the received sequence of clicks includes a periodic pattern. The periodicity of the pattern of clicks may be used to determine if the customer is a machine rather than a person. This may be useful in preventing fraud or spoofing. The sequence of clicks sent to the computing circuit 102 by the user ( 112 , 116 , 120 , 124 ) is received by the receiving circuit 104 , and transmitted via bidirectional communications means 126 to a memory circuit 128 for storage, and to a controller circuit 132 via bidirectional communication means 130 . The sequence of clicks may be an actual recording of the clicks as they were received by the user, or it may be a data file that includes the reception time of each of the individual clicks, or other method of transmitting information concerning the sequence of clicks, including arrival times, signal strength, and whether multiple clicks were received in a single time window. A flowchart of the steps of the operation of the computing circuit 102 is found in FIG. 2 , and will be discussed in greater detail below. The controller 132 transmits the sequence of discrete events via bidirectional communication means 134 to logic circuit 136 , and directs logic circuit 136 to calculate an appropriate window in time that will encompass a time period or temporal extent, over which the sequence of discrete events, in this example mouse clicks, was received by the user. A graphical example of the sequence of discrete events as a function of time is found in the upper half of FIG. 3 , and will be discussed in greater detail below. The controller 132 may direct the logic circuit 136 to calculate an autocorrelation function of the sequence of discrete events, the autocorrelation function comprising spikes representing pairwise differences in time received for each individual one of the discrete events in the window in time. An autocorrelation function has a form of R(t)=Σ i=1 N−1 Σ j=i+1 N δ(t, t j =t i ) where N is the number of discrete events, t is the time the clicks occur, and δ is the Kroneker delta, where δ(x,y)=1, if x=y, and zero if not. A graphical example of the autocorrelation function with respect to differences in arrival time is found in the lower half of FIG. 3 , and will be discussed in greater detail below. The autocorrelation function is an arithmetic sum of all of the spikes representing differences in time at which discrete events arrive. In this example the time difference between each of the clicks is shown as being very regular and consequently the autocorrelation is also very regular and shows a clear pattern, however, the describe apparatus is not so limited, and in common situations the arrival time of the discrete events would likely not be so regular due to variations in the electronic pathways that each individual event traverses on the way to the recording location of the user. The controller 132 may direct the logic circuit 136 to calculate a convolution R s between the autocorrelation function and an estimated jitter kernel to form a smoothed autocorrelation function having a set of peaks. A graphical example of the autocorrelation function of FIG. 3 including a representation of a jitter kernel is found in the upper half of FIG. 4 , and the resulting smoothed autocorrelation function is found in the lower half of FIG. 4 . It should be noted that the shape of the jitter kernel may be any function, and in particular any function that describes a probability distribution function for a random variable between members of the sequence of discrete events. For example, in some arrangements the jitter kernel takes the form of a Gaussian function of time difference t as follows: K(t)=e −t 2 /2σ 2 /√{square root over (2πσ)}, where σ is the standard deviation. Generally speaking, the jitter kernel may include a width that is indicative of the sort of noise, or travel delays, experienced by the mouse clicks discussed in the given examples. It should be understood that, in performing the convolution of the autocorrelation function with the jitter kernel, logic circuit 136 only considers 4 σ-wide regions which contain at least three peaks. The controller 132 may direct the logic circuit 136 to calculate an estimated period value, for example the value T shown in FIG. 4 , using a distance to a highest peak in the smoothed autocorrelation function. The highest peak corresponds to the time difference having the most individual discrete event occurrences, and thus is a valuable initial estimate of a possible periodic value. The logic circuit may now calculate a likelihood that the sequence of discrete events is periodic based upon the set of peaks and their locations. The controller 132 may direct the logic circuit 136 to calculate a second jitter kernel, where a width of the second jitter kernel is selected to be proportional to the period T, as found above and as shown in FIG. 3 . As an example calculation, the logic circuit may adjust the width of the initial kernel by a factor of the standard deviation being set to 0.1T, such that the width of the kernel would approximate 40% of the distance between each peak, and thus include spikes having substantial random delays in arrival at the recording location. It should be noted at this point that the second jitter kernel should be more accurate than the initial jitter kernel, which was not based upon the results of the present sequence of discrete events. Thus, the second jitter kernel may be either narrower or wider than the initial jitter kernel, and may result in a smoothed autocorrelation function having either wider or narrower peaks than the first smoothed autocorrelation. The second jitter kernel may be used in a convolution with the autocorrelation function to improve the accuracy of the smoothed autocorrelation. The controller 132 may direct the logic circuit 136 to calculate a second convolution between the second jitter kernel and the autocorrelation function to form a second smoothed autocorrelation function, as shown in FIG. 5 , where the example shows a Gaussian jitter kernel that is narrower than the first jitter kernel related to the use of the proportionality of the estimated period T for this sequence of discrete events being applied to the width of the jitter kernel. The controller 132 may direct the logic circuit 136 to calculate a periodicity measure as the sum of the values in the second smoothed autocorrelation evaluated at points T, 2T, 3T, etc. This may be known as the anomaly, or how much the calculated periodicity varies from a perfect period. The anomaly may be represented as an equation, anomaly=Σ n R s ′(nT). To generate a final score the anomaly value may be normalized by dividing by the number of spike timing differences used in the calculation. In the case of N spikes the normalization factor would equal (N(N−1))/2 if every possible time of arrival difference were to be included. In addition, it may be desirable to convert the normalized anomaly to a final score form more easily understood by users, by setting the final score to be equal to (1−(1−normalized anomaly))×(100) which provides a simple percentage value for use in evaluating whether or not a sequence of discrete events, such as clicks, has a periodic pattern. In an apparatus 100 , in order to enable what may be known as real time analysis of a sequence of discrete events for periodicity, considerations of the maximum computing speed available in computing circuit 102 may limit the number of discrete events or spikes that may be examined. This is because the number of pairwise time differences that need to be examined, and which enter into the calculation, increases as (N(N−1))/2 as the number of spikes increases. The memory requirements of memory 128 also increase, as well as other limitations of all of the entities shown in FIG. 1 , for example bandwidth in the network 108 . In view of these limitations, the number of discrete events or spikes allowed in a window of time may beneficially be limited to a constant value, for example 14 discrete events. In such a case, each new event could be added to the window, and an oldest event could be removed, to provide a rolling calculation of periodic patterns in real time. A computer program product which includes a non-transitory computer readable medium storing a set of computer instructions to perform the above described calculations and operations in a computerized device, may include a computer disk, such as disk 140 of FIG. 1 , which may be used to load instructions to a memory location, such as memory 128 of the computing circuit 102 . Many other well-known methods of providing computer instructions to a computing circuit may also be used. A method for calculating and providing the steps of evaluating a sequence of discrete events for a likelihood of periodic patterns will now be discussed with reference to FIG. 2 . FIG. 2 is a flowchart of steps in a method 200 for detecting periodicity and providing a confidence score that the detected periodic pattern is correct. The method begins at step 202 and the computing circuit 102 receives the sequence of discrete events to be analyzed at step 204 at the receiving circuit 104 . The sequence is examined by the logic circuit 136 under the control of the controller 132 and an appropriate window in time which contains a selected number of discrete events, for example 14 computer mouse or web clicks, is created at step 206 . At step 208 the logic circuit 136 generates an autocorrelation function of the sequence of discrete events, and forms a jitter kernel at step 210 , which may represent an estimation of a width of a distribution of random events occurring in the arrival of each of the discrete events, and affecting the timing of the arrival. At step 212 the logic circuit 136 generates a convolution between the initial jitter kernel and the autocorrelation function, and forms a first smoothed autocorrelation function at step 214 . At step 216 the logic circuit 136 finds a highest peak in the first smoothed autocorrelation function and generates a period value T at step 218 . A level of confidence may be obtained by the logic circuit 136 forming a second jitter kernel at step 222 , where the second kernel is formed with a shape that is calculated to better fit the sequence of discrete events than the first jitter kernel, which was estimated from known average variations. The second jitter kernel may be narrower or wider than the first. At step 224 the logic circuit 136 sets the second kernel width using the value T generated at step 218 to further refine the relationship of the width of the jitter kernel to the specific sequence of discrete events being examined. For example, the second jitter kernel may be formed having a standard deviation proportional to one tenth of the period T, and maybe determined to allow maximum arrival variation without missing an event. At step 224 the logic circuit 136 generates a second convolution using the second jitter kernel and the autocorrelation function. The convolution results in a second smoothed autocorrelation function R s ′ at step 228 , and the generation of a confidence score that provides the likelihood that the found periodic pattern with period T is actually a periodic function at step 230 . The level of confidence may be obtained by examining how closely the various multiples of the period T match with the actual peaks of the smoothed autocorrelation function. The method of detecting periodicity in a stream of discrete events ends at step 232 . FIG. 3 is a diagram showing the time of arrival of a sequence of clicks and an autocorrelation of the time differences between the arrival times of each of the clicks. An upper portion 302 of the graph shows a horizontal time axis 304 with five illustrated clicks 306 , 308 , 310 , 312 and 314 . Each of the clicks is shown as having arrived at a different time, and the time difference between the arrival times are shown as being equal, but the method and apparatus are not limited to regularly spaced arrival times, and normal random statistical variations are expected in real world situations. These normal variations are what the present arrangement is designed to measure and to determine if an actual periodicity exists in the sequence of discrete events, such as the clicks shown, or whether the sequence is simply random. A lower portion 352 of the graph shows a horizontal time delta axis 354 the results of an autocorrelation function performed with the spikes 306 - 314 , and resulting in groups of spikes 356 , 358 , 360 , 362 and 364 . The autocorrelation represents every pairwise combination of differences in arrival times for the spikes 306 - 314 . The example shows that the evenly spaced spikes 306 - 314 of the upper portion 302 of the graph result in an autocorrelation where the time differences are very bunched up and reflect a strong periodicity, but the normal real world result would likely be much less periodic and chaotic due to random time delays. FIG. 4 is a diagram showing a convolution of the autocorrelation of FIG. 3 with a jitter kernel and the resulting smoothed autocorrelation. The graph includes an upper portion 402 with a jitter kernel 404 convolved with the five shown groups of spikes 406 , 408 , 410 , 412 and 414 . The jitter kernel is shown as being a Gaussian function, but different window functions, such as raised cosine, Hamming, Hanning, or sin(ωt)/t, may be used as appropriate for the type of sequence of discrete events being evaluated. The jitter kernel will have a horizontal width measure, for example a standard deviation for a Gaussian function as shown, that may be selected to reflect the normal variations found in the environment of the discrete events. A lower portion 452 of the graph shows the result of the convolution of the jitter kernel 404 with an autocorrelation function, resulting in a smoothed autocorrelation function having peaks 456 , 458 , 460 , 462 and 464 . The time 454 between a start and a peak of the largest individual peak, in this example 456 , is labeled T* and may be used as an estimate of a period of the potential periodic pattern. FIG. 5 is a diagram showing a convolution of the autocorrelation with a second jitter kernel and the resulting second smoothed autocorrelation. The graph includes an upper portion 502 illustrating a second jitter kernel 504 convolved with the five shown groups of spikes 506 , 508 , 510 , 512 and 514 . The jitter kernel is again illustrated as being a Gaussian function, but has a different horizontal width as compared to the jitter kernel 404 of FIG. 4 , because jitter kernel 504 has been adjusted by a proportionality based in part upon the value T* found in FIG. 4 . For example, a Gaussian jitter kernel as shown may be selected to have a standard deviation of one tenth of T*. The second jitter kernel will have a horizontal width that may be greater or less than that of the first jitter kernel, but may be selected to better represent the actual variations found in the sequence of discrete events being examined for periodicity as compared to the first jitter kernel. In the example, the Gaussian second jitter kernel is shown as having a narrower horizontal width that the first jitter kernel, which may result in narrower autocorrelation peaks. A lower portion 552 of the graph shows the result of the convolution of the jitter kernel 504 with an autocorrelation function, resulting in a smoothed autocorrelation function (R s ′) having peaks 556 , 558 , 560 , 562 and 564 . The time 566 between a start and a peak of the largest individual peak, in this example peak 556 , is labeled T, while the time 558 between the start and a second highest peak 558 is labeled T2, and the time 570 to the third peak 560 is labeled T3. As many peaks as desired may be used in determining the elapsed time to various peaks of the second smoothed autocorrelation function. The values T, 2T, 2T and etc. may be compared with each other to determine if the value T to the first peak is close to a peak at the value of 2T, and close to a peak at the third value of 3T. Mathematical methods to determine if the measured times to each peak represent multiples of a single period, and to evaluate the probability that the determined period is actually a periodic pattern or not may be used. A confidence measure of the probability of periodicity may be computed as the sum of the points of R s ′ evaluated at the period T, at twice the period 2T, at three times the period 3T, and etc. While various embodiments of the invention have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Furthermore, it should be understood that some embodiments are directed to controller 132 , which is constructed and arranged to evaluate a likelihood that a sequence of discrete events displays periodic patterns. Some embodiments are directed to a process of evaluating a likelihood that a sequence of discrete events displays periodic patterns. Also, some embodiments are directed to a computer program product which enables computer logic to cause a computer to evaluate a likelihood that a sequence of discrete events displays periodic patterns. In some arrangements, controller 132 is implemented by a set of processors or other types of control/processing circuitry running software. In such arrangements, the software instructions can be delivered, within controller 132 , either in the form of a computer program product 140 (see FIG. 1 ) or simply instructions on disk or in pre-loaded in memory circuit 128 , each computer program product having a computer readable storage medium which stores the instructions in a non-volatile manner. Alternative examples of suitable computer readable storage media include tangible articles of manufacture and apparatus such as CD-ROM, flash memory, disk memory, tape memory, and the like.

Sequences of discrete events, such as clicks on a website, are evaluated for periodic behavior, a period is calculated, and the sequence is scored to determine the confidence that the sequence really exhibits periodicity. The random variations on the timing of the discrete events due to transmission delays or other factors may be reduced or eliminated from the evaluation. An apparatus for performing the method of evaluation may include a computer programmed to carry out the method.

BACKGROUND OF INVENTION [0001] Polymeric thin film electro-optical (EO) modulator devices based on guest nonlinear optical (NLO) chromophores dispersed in a polymeric material are known. The devices function because the NLO chromophores exhibit a high molecular hyperpolarizabity, which when aligned into an acentric dipolar lattice by an applied poling field, increases the EO activity. The performance of such devices is limited or diminished by the randomizing of the acentric order originally imposed on the lattice due to physical events within the polymeric material. These events include polymer creep, polymer glassy behavior above glass transition state, and chromophore/polymer phase segregation and aggregation. [0002] One approach to surmount these problems includes using a polymeric material exhibiting a relatively high glass transition state well above the operating temperature of the device. However, this strategy has been limited because the NLO chromophore has been found to exert a plasticizing effect on the polymeric material, thereby lowering the glass transition temperature of the composite material relative the undoped polymer. [0003] A second approach employs crosslinking the polymeric material to “fix” the orientation of the poled chromophores. Difficulty in controlling the reaction conditions during device fabrication has limited this approach. To be a viable approach, the crosslinking must not occur before poling is complete. Poling is generally conducted at temperatures at or about the glass transition temperature of the polymeric material. Therefore, the crosslinking needs to occur “on demand”. [0004] There remains a continuing need for still further improvements in the polymeric materials used to maintain the oriented NLO chromophore lattice. BRIEF DESCRIPTION OF THE INVENTION [0005] In one embodiment, a method for crosslinking a polymer comprises reacting i) a crosslinkable polymeric material comprising olefin groups and ii) a crosslinking agent comprising electron deficient olefin groups, at a temperature at which crosslinking occurs. [0006] In another embodiment, a method of fabricating a crosslinked polymer comprises mixing a crosslinkable polymeric material, a crosslinking agent, and a chromophore to form a mixture; forming a film from the mixture; aligning the chromophore; and heating the mixture to effect crosslinking reactions between the crosslinkable polymeric material and crosslinking agent. [0007] In yet another embodiment, a method for crosslinking a polymer comprises reacting i) a polycarbonate copolymer prepared from a bisphenol compound comprising two olefin groups and a 4,4′-[1-methyl-4-(1-methylethyl)-1,3-cyclohexandiyl]bisphenol and ii) 1,1′-(methylenedi-4,1-phenylene)bismalimide, 1,4-phenylene bismalimide, 1,4-di-1H-pyrrole-2,5-dione)butane, or a combination thereof, at a temperature at which crosslinking occurs. [0008] In another embodiment, a crosslinkable composition comprises a crosslinkable polymeric material comprising olefin groups; a crosslinking agent comprising electron deficient olefin groups; and a non-linear optical chromophore. BRIEF DESCRIPTION OF DRAWINGS [0009] FIGS. 1 a and 1 b include an idealized thermosetting of DABPA-co-BHPM polycarbonate copolymer via Ene and Diels Alder reactions; [0010] FIG. 2 is a graphical representation of the thermal cure of DABPA-co-BHPM polycarbonate copolymer in the presence of BMI (first heat); [0011] FIG. 3 is a graphical representation of the thermal cure of DABPA-co-BHPM polycarbonate copolymer in the presence of BMI (second heat); and [0012] FIG. 4 includes exemplary NLO chromophores. DETAILED DESCRIPTION [0013] Described herein are polymeric materials that can be crosslinked to “fix” guest NLO chromophores oriented by electric field poling prior to crosslinking of the polymeric material. The chemical crosslinking reactions subsequent to the induction of acentric order by electric field poling leads to enhanced, long term, thermal stability of the polymeric EO films used to prepare EO devices. The stability is thought to be due to the crosslinks limiting polymer creep and subsequent loss of the chromophores' defined orientation. [0014] Also disclosed herein is a method of crosslinking polymeric materials. The crosslinked polymeric material can maintain an ordered, acentric, dipolar chromophore lattice induced by electric field poling thereby providing both temporal and thermal stability of the EO films when incorporated into EO modulator devices. It has been found that polymeric materials comprising olefin groups can undergo crosslinking under thermal conditions in the presence of an electron deficient olefin-group-containing crosslinking agent. Not wishing to be bound by theory, it is believed that the olefin groups of the crosslinkable polymeric material react with the olefin groups of the crosslinking agent via an ene addition reaction to provide crosslinks. It is further believed that the resulting ene product can undergo a Diels Alder reaction with available olefin groups of the crosslinking agent to provide additional crosslinks. [0015] FIG. 1 a provides an idealized crosslinking reaction scheme between a polycarbonate copolymer and 1,1′-(methylenedi-4,1-phenylene)bis-maleimide (BMI). The exemplary polycarbonate copolymer (DABPA-co-BHPM PC copolymer) shown is prepared from 2,2′-diallyl Bisphenol A (DABPA) and 4,4′-[1-methyl-4-(1-methylethyl)-1,3-cyclohexandiyl]bisphenol (BHPM). As shown in FIG. 1 b, when the resulting Ene reaction product contains an olefin alpha to an aryl group, these groups are thought to further undergo a Diels Alder reaction with the remaining free olefin of the crosslinking agent resulting in a crosslinked polymeric material. [0016] The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. All ranges disclosed herein are inclusive and combinable. [0017] The crosslinked polymeric material can be prepared from crosslinkable polymeric material and a crosslinking agent. The crosslinkable polymeric material comprises olefin groups within or pendent from the polymer backbone, and more specifically terminal olefin groups pendent from the polymer backbone (—CH═CH 2 as opposed to —CH═CH—). More specifically, the terminal olefins groups of the polymeric material are pendant from an aromatic group as an allylaromatic. For example, polycarbonates prepared from 2,2′-diallyl Bisphenol A (DABPA) contain allylaromatics having pendent olefin groups. [0018] The crosslinkable polymeric material can include, for example, those of the following class: polycarbonates, polyamides, polyimides, polyetherimides, polyethylene sulfones, polyether sulfones, polyethylene ethers, polyethylene ketones, polyesters, polyacrylates, polyurethanes, polyarylene ethers, copolymers thereof, and the like. [0019] The crosslinkable polymeric material generally comprises 1 to about 50 mole percent olefin functionality, specifically about 2 to about 10 mole percent, and yet more specifically about 2 to about 6 mole percent olefin functionality. [0020] In one embodiment, the crosslinkable polymeric material is a polycarbonate copolymer exhibiting a high glass transition temperature and good film forming qualities. The polycarbonate copolymer can be prepared from a diol comprising at least one olefin group and 4,4′-[1-methyl-4-(1-methylethyl)-1,3-cyclohexandiyl]bisphenol (also identified as 1,3-bis(hydroxyphenyl)monoterpene or BHPM). Exemplary diols comprising at least one olefin group include 2,2′-diallyl Bisphenol A (DABPA), 4-(3-allyl-4-hydroxybenzyl)-2-allylphenol, bis(3-allyl-4-hydroxyphenyl)methanone, 4-(3-allyl-4-hydroxyphenylsulfonyl)-2-allylphenol, 4-(3-allyl-4-hydroxyphenylsulfinyl)-2-allylphenol, and the like. [0021] In an exemplary embodiment, the polycarbonate copolymer is prepared from BHPM and DABPA having a mol fraction of DABPA from about 0.01 to about 1, specifically about 0.05 to about 0.75, and more specifically about 0.1 to about 0.4. [0022] The crosslinking agent includes electron deficient olefin compounds comprising one or more adjacent electron withdrawing groups. Suitable electron withdrawing groups include carbonyl groups such as aldehyde, carboxylic acid, ester, amide, and ketone; nitrile groups; nitro groups; and the like. The crosslinking agent can comprise two, or more electron deficient olefin groups each comprising one or more adjacent electron withdrawing groups. [0023] An exemplary group of crosslinking agents comprising electron deficient olefins include a compound comprising at least two maleimide groups linked via the nitrogen atom to a C 1 -C 30 hydrocarbylene group. Exemplary crosslinking agents include 1,1′-(methylenedi-4,1-phenylene)bismalimide (BMI); 1,4-phenylene bismalimide; 1,4-di-1H-pyrrole-2,5-dione)butane; and the like. [0024] As used herein, “hydrocarbyl” and “hydrocarbylene” refer to a residue that contains only carbon and hydrogen. The residue may be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It may also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. The hydrocarbyl or hydrocarbylene residue, when so stated however, may contain heteroatoms over and above the carbon and hydrogen members of the substituent residue. Thus, when specifically noted as containing such heteroatoms, the hydrocarbyl or hydrocarbylene residue may also contain carbonyl groups, amino groups, hydroxyl groups, or the like, or it may contain heteroatoms within the backbone of the hydrocarbyl or hydrocarbylene residue. [0025] Stoichiometric ratios of the crosslinking agent to the amount of olefin groups from the backbone of the polymeric material can be used. Other amounts include 0.5 to about 10 equivalents of crosslinking agent per olefin group of the polymeric material, specifically about 1 to about 5 equivalents, and yet more specifically about 1 to about 2 equivalents of crosslinking agent per olefin group. Suitable nonlinear optical (NLO) chromophores that can be used to form EO films include those that exhibit good chemical stability under conditions of electric field poling. Exemplary NLO chromophores include so-called high-μβ chromophores comprising and electron donor group bound to a pi electron connective system, which is in turn bound to an electron acceptor group. A suitable NLO chromophore includes LM 46M (4-((1E)-2-(5-(4-(N-ethyl-N-(2-methoxyethyl)amino)styryl)-3,4-dihexylthiophen-2-yl)vinyl)-2-(dicyanomethylene)-2,5-dihydro-5,5-dimethylfuran-3-carbonitrile). [0026] The NLO chromophore can be selected to minimize any potential reaction between the chromophore and the crosslinkable polymeric material and/or crosslinking agent. By selecting, for example, sterically hindered chromophores, it is possible to crosslink the polymeric material without compromising the pi electron connective system of the chromophores. Such a selection can be made by one of ordinary skill in the art without undue experimentation. [0027] The chromophore may be used in amounts of about 10 to about 35 weight percent based on the polymer, specifically about 15 to about 30 weight percent, and yet more specifically about 20 to about 25 weight percent. [0028] Prepared solutions of crosslinkable polymeric material, crosslinking agent, chromophore, and optional solvent can be formed as thin curable films on a substrate, such as polymeric or silicon substrates. The solvent of the solution can be removed by evaporation, optionally with heating and/or vacuum to result in a crosslinkable film. The crosslinkable film can be heated to temperatures sufficiently above the Tg of the crosslinkable polymeric material so that poling can be used to induce the formation of an acentric dipolar lattice while the material is in a glassy state. Once the chromophores have been poled, the temperature is increased to induce crosslinking via Ene or Ene and Diels Alder reactions between the crosslinkable material and crosslinking agent. [0029] The thin crosslinkable films can be formed by spin casting, dipping, spray coating, silk screening, doctor blading, ink jetting, and the like to form a thin film of the composition, more specifically spin casting. Solvents that are suitable for film forming include those that can solubilize the polymeric material, but are inert to the components of the film. Substrates on which the films are form may be of any material including, for example, polymeric or silicon substrates. [0030] In an exemplary embodiment, the crosslinked film can be prepared by mixing a crosslinkable polymeric material comprising pendent olefin groups, a crosslinking agent, and NLO chromophore with a suitable solvent to form a mixture. The mixture is then applied to a substrate, either by spin coating, casting, dipping, etc., and then the solvent is allowed to evaporate to leave a crosslinkable film comprising the crosslinkable polymeric material, crosslinking agent, and chromophore. The crosslinkable film is heated to at or slightly above the glass transition temperature of the film and an electromagnetic field is then applied to the crosslinkable film to cause a poling of the chromophore present therein. The chromophore molecules align relative to the direction of the applied field. While maintaining the electromagnetic field, the crosslinkable film is heated to temperatures sufficient to induce crosslinking of the olefin groups of the polymeric material with the crosslinking agent by Ene and possibly even Diels Alder reactions. The crosslinking fixes the aligned chromophore molecules thereby providing a cured film having non-linear EO properties. It is believed that the crosslinking will provide an increase in the lifetime of the device after poling by maintaining the chromophore orientation longer than the corresponding non-crosslinked polymers. [0031] The crosslinking of the crosslinkable polymeric material and crosslinking agent occurs under mild conditions at temperatures at or just above the glass transition temperature of the crosslinkable film. These temperatures are sufficient to provide cure while at the same time low enough so that decomposition of the other components of the film does not occur. Temperatures suitable to induce crosslinking can be about 150 to about 350° C., specifically about 200 to about 300° C., and more specifically about 200 to about 275° C. [0032] The time of heating to induce crosslinking is dependent upon the crosslinkable polymeric material employed and the crosslinking agent used. Exemplary reaction times to induce crosslinking can be about 2 to about 60 minutes, specifically about 3 to about 20 minutes, more specifically about 4 to about 10 minutes, and yet more specifically about 2 to about 5 minutes. [0033] The crosslinked films comprising oriented NLO chromophores can be used for a variety of applications, including for example, electro-optical waveguide materials, Mach Zehnder modulators, optical switches, variable optical attenuators, narrow band notch and bandpass filters, digitally tuned gratings, optical frequency mixers, and electro-optical devices including organic light-emitting diodes and photo diodes. [0034] In another embodiment, the crosslinkable polymeric material in combination with a crosslinking agent, but without the chromophores, can find use in non-EO applications as a coating material with on-demand cure. EXAMPLES Examples 1-4 Synthesis of DABPA-co-BHPM PC Copolymer [0035] DABPA-co-BHPM PC copolymers comprising varying amounts of pendent olefin groups were prepared by reacting a mixture of 1,3-bis(hydroxyphenyl)monoterpene (BHPM, internally prepared), and 2,2′-diallylbisphenol A (DABPA, n=0.1, 0.2, 0.3, and 0.4, Aldrich Chemical Co., purified prior to use) with excess phosgene, and in the presence of pyridine or triethylamine. An amount of 1.5 mol percent of 4-Cumylphenol (Aldrich Chemical Co.) was used as a chain stopper. [0036] Alternatively, the copolymers were prepared under interfacial phosgenation conditions using methylene chloride as the solvent, aqueous sodium hydroxide as the base and (0.1-1 mol %) triethylamine as the catalyst. The processes used for the preparation of the copolymers were not optimized and exhibited a slight excess of BHPM relative to the mole fraction of DABPA, presumably due to a difference in the monomer reactivity ratios under the condensation polymerization conditions used. [0037] Table 1 summarizes the weight average molecular weight (M w ), the number average molecular weigth (M n ), and the polydispersity index (PDI, M w /M n ) for the DABPA-co-BHPM PC copolymers obtained by gel permeation chromatography (GPC). TABLE 1 Mol Fraction M n M n Example DABPA M w (Exp) (Theory) M w /M n 1 0.1 11664 5598 23383 2.084 2 0.2 15148 5794 23279 2.615 3 0.3 17481 7142 23175 2.448 4 0.4 28354 8677 23071 3.268 [0038] A differential scanning calorimetry (DSC) study was undertaken to evaluate the thermal cross-linking of the DABPA-co-BHPM polycarbonate copolymers of Examples 1-4 using 1,1′-(methylenedi-4,1-phenylene)bismalimide as the crosslinking agent. The DSC thermal analysis was completed using a Perkin-Elmer DSC7 differential scanning calorimeter. 1,1′-(Methylenedi-4,1-phenylene)bismalimide (BMI, Aldrich Chemical Co.) was added without further purification to each polycarbonate copolymer formulation to obtain a theoretical stoichiometry of 0.5 allyl equivalents per BMI. All sample copolymer formulations were prepared by evaporatively casting films of filtered (Whatman Uniprep™ syringeless filters, 0.45 micrometer polytetrafluoroethylene membrane) CH 2 Cl 2 solutions containing dissolved copolymer and BMI. All DSC sample measurements were referenced to an indium standard (melting point (mp) 156.60° C., ΔH r =28.45 J/g) using a dual pan configuration under a nitrogen (N 2 ) purge gas. Typical sample masses ranged from 10 to 15 milligrams (mg), and all samples were compressed into pellets sized to fit an aluminum sample pan to maximize heat flow while minimizing thermal lag in the sample. Typical cycles for the first heat and second heat are listed in Table 2 below. DSC scanning kinetics data collection and manipulation was made using the Pyris V5.00.02 software package. No attempt was made to correct the data generated by normalizing it relative to M w , M n , composition, or mass variations between sets of replicate runs. TABLE 2 Typical DSC experimental heat flow cycles (endothermic event up) Heat Cycle Step Step Description 1 1 Hold for 2.0 min at 25.00° C. 1 2 Heat from 25.00° C. to 425.00° C. at 10.00° C./min 1 3 Cool from 425.00° C. to 25.00° C. at 10.00° C./min 2 4 Hold for 5.0 min at 25.00° C. 2 5 Heat from 25.00° C. to 425.00° C. at 10.00° C./min 2 6 Cool from 425.00° C. to 25.00° C. at 10.00° C./min [0039] In this screening model study, the thermal cross-linking of DABPA-co-BHPM polycarbonates with BMI was probed in situ using DSC thermal analysis. As indicated in FIG. 1 a, DABPA-co-BHPM polycarbonates are thermoset at temperatures from 130-200° C. as electron deficient BMIs react via an Ene addition to the electron rich diene in the form of an ortho-allylphenyl function. The first and second that for each of the DABPA-co-BHPM/BMI formulations Examples 1-4 is shown in FIGS. 2 and 3 , respectively. The T g for the undoped and uncured polycarbonate copolymers is summarized in Table 3. TABLE 3 Example Polymer Tg (° C.) Control BHPM 250 Example 1 DABPA-co-BHPM (n = 0.1 215 DABPA) Example 2 DABPA-co-BHPM (n = 0.2 185 DABPA) Example 3 DABPA-co-BHPM (n = 0.3 172 DABPA) Example 4 DABPA-co-BHPM (n = 0.4 159 DABPA) [0040] An interpretation of the results for the 1 st and 2 nd heat of the DABPA-co-BHPM PC copolymer formulations is as follows. In FIG. 2 , heat flow is seen to increase as the temperature is ramped, consistent with an upward slope of the heating curve. At T=156° C., the unreacted BMI dispersed within cast films of the DABPA-co-BHPM PC copolymer formulations is undergoing an endothermic phase transition as the solid BMI melts. The integrated area under each curve increases roughly in proportion to the concentration of the solid BMI dispersed within the polycarbonate copolymer formulation, that is, the concentration of dispersed BMI increases from heating curve 1 to 4 (n=0.1-0.4 DABPA, respectively). This transition is reproducible between the different polycarbonate compositions, occurring at the reported melting point for 1,1′-(methylenedi-4,1-phenylene)bismaleimide (mp=156-158° C.), and this in turn is consistent with a discrete, low molecular weight component dispersed within the copolymer matrix. [0041] After the BMI has melted, heating continues until the onset of curing at approximately 185° C., as suggested by a broad, shallow exothermic event evident in all of the heating curves. This interpretation is consistent with several additional observations. First, the T g associated with any of the unreacted polycarbonate copolymers (Table 3) were not observed. Secondly, there is no hysteresis observed in the heating curve for the 2 nd heat ( FIG. 3 ), that is, neither an endothermic event associated with the melting of BMI or an exothermic event associated with thermal curing are observed in the 2 nd heat. Indeed, it should also be readily apparent that there are no observable transitions associated with unreacted DABPA-co-BHPM PC copolymers, e.g., T g (Table 3). This result implies that a thermal cross-linking event has occurred, resulting in a cross-linked network. The results further suggest BMI acts as a cross-linking agent to form a polymer network that is distinct from the original starting materials used to form the network. The resultant polymer network does not exhibit any detectable T g under the thermal treatment describe using DSC methods. Example 5 T g of Doped DABPA-co-BHPM PC [0042] Samples of DABPA-co-BHPM PC containing varying amounts of DABPA were doped with chromophore LM 46M at 25 weight percent loadings and measured for Tg. A distinct trend in the reduction of the glass transition temperature was observed with the incorporation of the chromophore. TABLE 4 Example 5 Tg (° C.) of copolymer doped with (Mole fraction of DABPA) 25 wt. % chromophore 0.1 133 0.2 122 0.3 110 0.4 100 [0043] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Crosslinkable polymeric materials are disclosed useful for the temporal stabilization of a poling-induced noncentrosymmetric host lattice containing guest nonlinear optical chromophores. The materials are also suitable as crosslinkable coatings in the absence of chromophores. Also disclosed is a method of crosslinking such polymeric material.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a method and a device for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces, wherein the heatable process gases include a treatment medium as a protective gas and/or for example a reaction gas. [0003] 2. Description of the Related Art [0004] In general, a process gas for the heat treatment of metallic materials/workpieces in industrial furnaces is understood by a person skilled in the art to be a treatment medium such as for example a protective gas containing carbon monoxide, hydrogen and nitrogen, carbon dioxide oxygen and/or steam, and/or for example a reaction gas containing hydrocarbons for “carburisation processes”, which relate to the carburising or carbonitriding of metallic materials/workpieces. [0005] Thus, in one of the steps of carburisation for example, a gas containing hydrocarbons is added to a process gas reacting in the treatment chamber to create the requisite furnace atmosphere. In this process, the individual components of the process gas are intended to create a controllable state of equilibrium in the furnace atmosphere so that the carbon is able to be transferred from the gas atmosphere to the metallic materials/workpieces in a manner that is both controlled and reproducible. Automatic control of processes of this kind is assured by regulation of the C level, such as is described in DE 29 09 978 and has become successfully established in industrial practice for the heat treatment of metallic materials/workpieces. However, the control of the C level solved so advantageously here fails to make use of catalytically usable potential with regard to modern requirements. [0006] Thus for example, in his report entitled “Gas mixtures fed hot into the furnace chamber as the atmosphere for heat treatment of steel”, (HTM 30 (1975) Vol. 2, p. 107-) W. Goring had already suggested using a protective gas retort with catalyst bed integrated in the industrial furnace to feed hot process gas into the treatment chamber, regardless of the temperature there, as a way to speed up the level of activation of a furnace atmosphere. For the purposes of modern specifications, this method is associated with a number of drawbacks, because it requires constant replenishment with fresh gas, that is to say regulation is effected by enriching the gas, and harmful emissions must be contended with. [0007] The use of catalysts is also described in other documents, such as for example DE 36 32577, DE 38 88 814, DE 40 05 710, DE 691 33356, and DE 44 16 469. [0008] The following text discloses the treatment of metals in a carburised atmosphere in accordance with GB 1,069,531, in accordance with U.S. Pat. No. 3,620,518 for the treatment of workpieces in hardening furnaces having a catalyst lining of nickel oxide, which has been applied to the ceramic interior wall and increases the available surface area, in accordance with U.S. Pat. No. 4,294,436 with a furnace for heat treatment of metal parts with a protective atmosphere in furnaces having catalytic walls of Ni, in accordance with U.S. Pat. No. 5,645,808 for catalytic oxidation with carbon compounds in gas streams, and in accordance with US 2006/0081567 with plasma-supported workpiece treatment, and in accordance with JP 62199761. [0015] In order to improve the process effect of the gas feed in the abovementioned industrial furnaces, it has already been suggested in DE 10 2008 029 001.7-45 to tailor the supply of hydrocarbon to specific carburisation requirements so as to economise on protective gas and reduce heat energy losses, to adjust the C potential in the protective gas and prevent uncontrollable and/or undesirable reactions. This resulted in the creation of a new protective gas recirculation system for gas carburisation. In this, the components carbon dioxide, oxygen and steam react with a supplied hydrocarbon in a processing area of the treatment chamber of a species-related industrial furnace to yield carbon monoxide and hydrogen again, in this case catalytically. In this way, previously “used” protective gas, that is to say a protective gas with a low C potential, may be advantageously reprocessed. The C potential is adjusted in the processing area of the treatment chamber. The “processed” protective gas may then be fed back into the treatment chamber at one or more points, thus establishing a truly circular process for gas carburisation. [0016] According to this new method the components carbon dioxide, oxygen and steam react with a fed supply of a hydrocarbon as the reagent gas to yield carbon monoxide and hydrogen in a processing area equipped with catalyst bed in an industrial furnace, the protective gas has elevated C potential, and the C potential is adjusted, the catalytic reaction is accelerated, and the protective gas processed in this way is returned to the treatment chamber in a recirculation system. [0021] The purpose of this was to improve the process of uniform carburisation and enable costs for process gas to be reduced further. [0022] However, more extensive research was needed in order to ensure even more reliable and reproducible heat treatment for industrial furnace operators, because the method described above requires the treatment chamber and the heating chamber to be as impermeable as possible, and reaction temperatures in the heating chamber do not exceed for example 850-950° C. [0023] In this context, the quality requirements for case hardening had to be analysed again, particularly with respect to parameters such as case hardening depth/carburisation depth, surface hardness/surface carbon content, perlite/troostite seam, residual austenite content, carbide formation, surface oxidation depth as well as dimensional and shape changes and core hardness if they were to be correlated even indirectly with the degree of carburisation. In this case, the depth of carburisation and the carbon concentration were both significant factors. [0032] In the existing industrial carburisation methods, such as gas carburisation in atmosphere furnaces and low-pressure carburising in vacuum furnaces, the objective is one that is familiar to those skilled in the art: all parts of the workpieces in a batch must be carburised with total uniformity, to the same C content and the same carburisation depth. [0033] With gas carburisation, in which the furnace atmosphere is adjustable via equilibrium reactions, this may be achieved more effectively than by non-equilibrium carburisation using hydrocarbons. [0034] Accordingly, gas carburisation, that is atmospheric gas carburisation, is the preferred process. [0035] In this process, the following known, various process steps are performed, it is essential to take all of them into account to ensure reproducible, even carburisation: 1. The gas reactions for creating the carburising gas components in the atmosphere. 2. Gas phase homogenisation for transporting the carbon-containing molecules in the gas phase and to the part to be carburised. 3. Diffusion transport, that is to say transport of the carbon-containing molecules by the flow boundary layer to the surface of the part. 4. Dissociation and adsorption relating to splitting of the molecules on the surface of the part. 5. Absorption, that is to say the uptake of the carbon by the part surface. 6. Diffusion as the means of transporting the carbon into the part. [0042] As has already been described in the outcome in DE 10 2008 029 001.7-45, the decisive reactions for carburisation in the carburisation atmosphere are: [0000] CH 4 C+2H 2   Methane dissociation [0000] 2CO C+CO 2   Boudouard reaction [0000] CO+H 2 C+H 2 O   Heterogeneous water-gas reaction [0000] CH 4 +CO 2 2CO+2H 2   Enrichment reaction 1 [0000] CH 4 +H 2 O CO+3H 2   Enrichment reaction 2 [0043] In order to build on the advance represented by DE 10 2008 029 001.7-45 with regard to the prior art, it is important to influence the kinetics and also the direction of these reactions, because they depend to a large degree on the temperature which—as was explained previously—is regularly limited to 850-950° C., but are not enabled at temperatures significantly below this. [0044] Since the transportation of the carbon carrier is usually effected through forced convection, the powerful circulation of the atmosphere within the heating chamber helps to ensure that the carbon carriers are thoroughly mixed and the flow thereof is then directed towards the part. [0045] Thus, for example, the following relationship is known to apply for mass transfer when the atmospheric flow is directed towards a flat workpiece panel [0000] β L = 0.664 × V · L ν × ν D 3 × D L , [0000] wherein a coefficient of diffusion is represented by D; a length of the part to which flow is directed is represented by L; a flow speed is represented by V; and a kinematic viscosity is represented by ν. [0049] Accordingly, as the flow speed increases the effective coefficient of mass transfer β also becomes larger, and it is this relationship that must be used even more efficiently. [0050] The known relationship to the effect that the speed of diffusion through the flow boundary layer is essential and cannot be influenced by changing the flow speed had to be studied further. [0051] In this regard, it is the magnitude of the coefficient of diffusion in the gas that is decisive, and this is critically dependent on temperature and pressure. In an initial approximation—also known—, doubling the pressure halves the diffusion coefficient. [0052] The thickness of the boundary layer may be determined using the relationship familiar to those skilled in the art [0000] δ  ( x ) = 4.64  ν · x V ∞ [0000] where thickness of the boundary layer is represented by δ(x); distance from the edge of the part is represented by x; and speed of the gas farther from the part is represented by V ∞ . [0055] It may be observed that increasing the speed of the gas reduces the thickness of the boundary layer, which in turn shortens the transport time to the surface. Use of this relationship must be improved as well. [0056] Finally, the splitting reaction of the carbon monoxide on the part according to the known equation [0000] C   O ⇒ C + 1 2  O 2 [0000] is also the underlying reaction for transferring carbon for gas carburisation in CO/H mixtures, which, besides still other reactions, enables the carburisation effect of the atmosphere to take place continuously, as is shown in FIG. 1 , which illustrates known findings. [0057] In order to arrive at advanced solutions proceeding from this known basis, the creative approach had to be applied and exploited in a technologically new way, in particular that the speed of carbon transfer depends on the property of the atmosphere, and the oxygen generated during splitting must be bound and then removed by convection. [0060] Since hydrogen is needed for this, the speed of dissociation of the carbon monoxide in the presence of a sufficiently large quantity of hydrogen becomes the determining parameter. [0061] The speed at which the carbon is absorbed by the workpiece surface in turn depends on the difference between the carbon activities in the atmosphere and in the part. This means, if the carbon activity in the gas is greater than in the part, the net effect is a transfer of the carbon to the workpiece surface. [0062] In practice, this difference may be characterized in pure iron and unalloyed steel by the difference between the C potential and the carbon content in the workpiece surface, wherein the diffusion of the carbon can be described by Fick's laws, which will not be further elaborated on here. [0063] Accordingly, a new inventive task must address the fact that diffusion depends on the temperature and the progression of the concentration of carbon C in material having depth x. SUMMARY OF THE INVENTION [0064] In the context of these detailed investigations, the object of the invention is to provide a method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces of the species described, by which at least one of the components containing a process gas, having been practically completely prepared, and also homogenised and heated, is fed into the at least one treatment chamber thereof and is able to be connected by a device both to newly manufactured as well as and particularly to units of industrial furnaces that have already been in service, such that the process gas is able to be used for heat treatment in the respective industrial furnace economically and with low emissions, and ideal carburisation conditions in terms of temperature, gas flow towards the parts, homogenisation of the gas phase, and rapid reaction kinetics are created uniformly throughout the treatment chamber of the industrial furnace in accordance with the six process steps listed above. [0069] Unlike the prior art, the invention is therefore intended for industrial furnaces, particularly those referred to as atmosphere furnaces, in which previously the components of the process gas to be heated were normally prepared in the treatment chamber as the heating chamber, before they were introduced for carburising or carbonitriding heat treatment of metallic workpieces/materials, wherein in an upstream process and with a device that may be connected to the industrial furnace, the process gas is practically entirely prepared beforehand and then fed into the treatment chamber with direct effect so that the heat treatment process may be carried out in a more efficient, more environmentally responsible manner for operators in the industry, and to provide a corresponding unit that is able to be retrofitted in older industrial furnaces. [0070] With this statement of the object, approaches to finding inventive solutions are informed by the fact that the temperature in both the treatment chamber and the heating chamber of modern industrial furnaces can be maintained with a uniformity of at ±5° C. This means that when the heating and soaking phase is finished, all austenised parts are at the same temperature. [0071] If special gas feed devices are also arranged inside the heating chamber, they already enable the remaining convective heat transfer portions to be used in a defined way to achieve the all-important uniformity of temperature throughout the entire batch chamber. In certain cases, it is then possible to achieve tolerances of just ±3° C. [0072] Ideal temperature uniformity can only be established if the gas flow is directed to all parts optimally. Accordingly, excellent temperature uniformity needs another circulation system, or more importantly one that has been devised differently from previous systems, and which must be considered as a unit. [0073] Besides establishing temperature uniformity and optimal exposure of the parts to the carburising gas flow, a third aspect of circulation to be considered is homogenisation of the atmosphere, which enables the gas reactions for initiating consistent carbon activity (C level) to be sustained throughout the batch chamber and in the treatment chamber. [0074] In order to set a defined atmosphere, continuous gasification with carrier and enrichment gas must always be adjustable directly via the circulation system. [0075] The continuous interaction between the furnace atmosphere and the surface of the workpiece, and the associated transfer of carbon from the gas causes the carbon activity (C level) in the atmosphere to change constantly, so that it is imperative to measure this variable. This is assured with the aid of the oxygen probe (and thermoelement) on the basis of an oxygen partial pressure measurement. Natural gas (or another hydrocarbon) is added to the air to adjust the C potential. [0076] Accordingly, carburisation of the parts and the enrichment of the process atmosphere necessitated thereby leads to a permanent imbalance therein. Balanced adjustment of the C level must create a quasi-stationary equilibrium in generating a generally balanced atmosphere despite these locally occurring imbalances, and this is illustrated in FIG. 2 to provide a better understanding of the object of the invention in the circular gas carburisation process that is central to the invention. [0077] In this figure, the carburisation reactions responsible for carburisation, all of which lead to the formation of carburising carbon monoxide, are shown on the left. [0078] One carburising reaction appears at top right in FIG. 2 , that is unbalanced carburisation due to methane dissociation. A locally occurring, impermissible increase in the concentration of methane in the CO- and H 2 -containing process atmosphere can result in partial overcarburisations on the parts, which then in turn cause residual austenite and/or carbide formation. Methane dissociation is not normally detected by the sensors, and consequently it is most often perceived as an interference factor during the process. [0079] However, it is possible to achieve the interaction between gasification and adjustment of the C level within the atmosphere according to an internal development stage, wherein this interaction is defined by the maintenance of a tolerance of ±0.05% C in the surface carbon content of the workpiece, and results in uniform carburisation of the surface layer. [0080] If a person skilled in the art assumes the degrees of effectiveness that are achievable using the carburisation gasification techniques that are standard today, he would recall that in operating industrial furnaces thermal losses occur such as in the flare when the protective gas is burned off, and approximately 98% of the carbon that is fed into the carburisation process is not available for carburising at all, instead it is merely burned off, so that the degree of efficiency in carburisation is thus less than 2%, and other technologies are addressing the question of how to exploit the heat energy that is discharged into the ambient air. [0085] A new gasification process was already proposed in the document DE 10 2008 029 001.7-45 cited above, according to which the protective gas is no longer burned off, but instead is returned to the heating chamber by recirculation after undergoing an intermediate step as preparation, and is thus no longer dissipated, but reused. [0086] The purpose of this invention is now to take the process another important step forward, in which the reactions proceeding within the heating chamber due to carburisation, such as: [0000] 2CH 4 +O 2 2CO+4H 2 [0000] CH 4 +CO 2 2CO+2H 2 [0000] CH 4 +H 2 O O CO+3H 2 [0000] have been examined again with regard to more interference factors. [0087] According to this, the intention was to enable better use to be made of the catalytic potential, to ensure that above 850° C. the temperature actually required in the furnace chamber does not result in reprocessing of protective gas that has already been “consumed”, a process that while advantageous on its own has negative effect on the reactions, to ensure that the catalytic effect is guaranteed regardless of the temperature in the furnace chamber, that is to say significantly above but also below temperatures, and to ensure that the enrichment gas is passed directly through the catalyst, and not fed into the furnace chamber first. [0092] Unlike previous approaches, in the present invention the protective gas is to be generated and enriched in a distinct preparation process, separately from the batch, so that it is possible to expose the batch to a gas atmosphere that is consistently homogeneous. As a result, streaks or inconsistencies are not formed when natural gas is introduced into the heating chamber for the purpose of enrichment. Undesirable local overcarburisations, such as are caused by unbalanced carburisation due to the methane dissociation described above, are to be almost entirely prevented. [0093] The low environmental impact of the method is demonstrated by its carbon footprint. CO 2 emissions are lowered significantly by the extensive economies in process gas. [0094] Although it has not yet been possible to use the information gained from DE 10 2008 029 001.7-45 for a wide range of industrial furnaces of the species described in the introduction that are already in service, a further field of application is now accessible by virtue of the fact that it is possible to retrofit existing industrial furnaces, and thus achieve even greater efficiency than was offered by the method according to DE 10 2008 029 001.7-45. In particular, older inventories of industrial furnaces that are at operators' sites and still operable are able to be retrofitted according to the invention. [0095] Starting from the prior art situation described in the preceding, this newly gained knowledge may now be applied to a wide range of currently operating industrial furnaces of the technological species described in the introduction. Although some of these solutions were implemented, for example a protective gas retort with protective catalyst bed integrated in the industrial furnace, they were only implemented as integrated components of furnace units and involved the disadvantageous supply of enrichment gas but not gas recirculation. [0096] It was also typical and disadvantageous in such arrangements that the process gases were always prepared under the conditions prevailing in the respective treatment chamber as the heating chamber and directly associate functional units. Accordingly, it was not possible to prepare the gases under higher or lower temperature conditions. [0097] The present invention now makes it possible for operators' existing older industrial furnaces, which are still serviceable but are not yet being operated with the full range of commercial/technological and ecological advantages, to be run in an environmentally conscious manner and with economical use of energy carriers. [0098] The invention provides a method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces, by which at least one of the components containing a process gas, having been practically completely prepared, and also homogenised and heated, is fed into the at least one treatment chamber thereof and is able to be connected by a device both to newly manufactured as well as and particularly to units of industrial furnaces that have already been in service, such that the process gas is able to be used for heat treatment in the respective industrial furnace economically and with low emissions. [0099] Unlike the prior art, the invention enables industrial furnaces, particularly those referred to as atmosphere furnaces, in which previously the components of the process gas to be heated were normally prepared in the treatment chamber as the heating chamber, before they were introduced for carburising or carbonitriding heat treatment of metallic workpieces/materials, an upstream method and a device that may be connected to the industrial furnace enables the process gas to be processed in the manner explained in the preceding, wherein the actual preparation process is able to take place and is favoured by higher reaction temperatures up to about 1250° C. and at significantly lower reaction temperatures, that is to say higher and lower than the temperature of 850° C.-950° C. in the treatment chamber, and that in this context particularly accelerated reactions such as enrichment and generation, as described for example by [0000] 2CH 4 +O 2 →2CO+4H 2 [0000] CH 4 +CO 2 →2CO+2H 2 [0000] CH 4 +H 2 O→CO+3H 2 [0000] are encouraged and able to take place, so that this process gas may then be fed directly to the treatment chamber of the industrial furnace, so that the carburising reactions there, for example [0000] 2CO→C+CO 2 [0000] CO+H 2 →C+H 2 O [0000] CO→C+0.5O 2 [0000] are able to take place with direct effect at the usual, cited temperatures. [0100] In this context, other reaction equations in keeping with the central idea of the invention may also take place depending on the corresponding heat treatment method and the gas components for preparing the process gas and the treatment-related consumption thereof for the purposes of central idea of the invention. [0101] The entire heat treatment process may thus be carried out by operators in the industry in an even more efficient and environmentally conscious manner, for which purpose the corresponding unit has been created so that according to the invention it is able to be retrofitted in older industrial furnaces. [0102] In summary, the sequence of the method is configured according to the invention such that the process gas, which includes at least a first treatment medium as a protective gas, which also contains the components carbon dioxide, oxygen and steam in addition to the minimum components carbon monoxide, hydrogen and nitrogen, and a second treatment medium as a reagent gas, which initiates a carburising or carbonitriding treatment, a) is prepared separately with regard to at least one of the properties thereof that is essential for heat treatment, such as chemical reactions, temperatures, pressures or flow speeds, in a preparation chamber of an external module outside of the treatment chamber and the industrial furnace at temperatures of up to 1250° C. and with the use of a compressor according to the following reactions, for example, [0000] 2CH 4 +O 2 →2CO+4H 2 [0000] CH 4 +CO 2 →2CO+2H 2 [0000] CH 4 +H 2 O→CO+3H 2 [0000] such that the components such as carbon dioxide, oxygen and steam react catalytically with a hydrocarbon as the reagent gas to form carbon monoxide and hydrogen, and after this reaction the protective gas has a required C potential, after which b) the process gas thus prepared is forced out of the preparation chamber of the external module by the compressor and fed to the treatment chamber in the industrial furnace, having been compressed, homogenised and accelerated, and is directed via single-point or multipoint feeds towards the materials/workpieces, where the carburising or carbonitriding treatment is carried out according to the following reaction, for example, [0000] 2CO→C+CO 2 [0000] CO+H 2 →C+H 2 O [0000] CO→C+0.5O 2 [0000] wherein c) at least one treatment medium of the process gas is recirculated and is recovered for use in the preparation described in step a). [0108] Experience has shown that the gas passing through pipelines can undergo a reactive breakdown, depending on the length and diameter of required pipe connections between the treatment chamber and preparation chamber. [0109] This is to be avoided by rapidly cooling the gas after it exits the treatment chamber, or even after it exits the preparation chamber. [0110] As an alternative, achieving the high gas temperature by insulating and, if necessary, heating the pipelines also constitutes a suitable means for avoiding gas breakdown. [0111] In the device for implementing the method, the respective pipeline must correspondingly have allocated to it a cooling aggregate, e.g., designed as ribbed pipe piece with ducted or induced cooling, or an insulation or heater, in particular directly behind the treatment chamber or behind the preparation chamber. [0112] With this method, it is possible to produce a process gas that has been compressed, homogenised, and heated to a higher, but also to a lower temperature, which process gas together with at least one second treatment medium as the reagent gas containing a hydrocarbon and also ammonia as components causes carburising and/or carbonitriding during heat treatment of materials/workpieces or the treatment medium thereof, wherein at this point at least one treatment medium of the process gas fed into the treatment chamber of the industrial furnace is recirculated in the treatment chamber for separate reconstitution. [0113] The process gas is processed separately and catalytically in the module described to yield a circulation/mixture that is optimised for heat treatment and is able to overcome flow resistances with the assistance of the compressor, for subsequent, direct use in heat treatment in the industrial furnace. [0114] By the time it reaches the industrial furnace, the process gas has thus been prepared, fully reacted, compressed, homogenised and accelerated, so that the carburising effect is able to take place directly on the workpieces/materials directly in the treatment chamber of the industrial furnace without the need to perform the reactions and preparation in the treatment chamber, as previously, and then control/adjust the treatment medium according to the C level as a function of the workpieces/material that are to be treated. [0115] The composition of the gas siphoned out of the treatment chamber and relayed into the preparation chamber varies as a function of the level of thermochemical gas reactions and gas metal reactions taking place in the treatment chamber. [0116] In terms of the input/output monitoring described in the invention, the gas is to be optimally prepared in the preparation chamber by precisely adjusting the unburned gases being fed into the preparation chamber, e.g., natural gas and air, along with other hydrocarbons and other oxidizing gases, relative to a supplied overall quantity and ratio of supplied individual quantities, based on the quantity and composition of the gas to be prepared and the desired preparation result. [0117] In a thermochemical heat treatment process, such as carburisation or carbonitration, the overall composition in the treatment chamber varies throughout the entire duration of the process. Therefore, an optimally prepared reaction gas cannot be generated by supplying a chronologically constant quantity of unburned gas in a chronologically constant ratio of the individual unburned gas components into the preparation chamber. [0118] The inventive process of optimal gas preparation is set up therein from a procedural standpoint by measuring the composition, streaming quantity and temperature of the gas to be prepared after exiting the treatment chamber and before entering the preparation chamber, and of the prepared gas after exiting the preparation chamber and before entering the treatment chamber, and continuously changing the entire quantity of unburned gas fed into the preparation chamber along with the relative quantities of individual unburned gas components relative to each other, so as to achieve an optimal preparation result. [0119] The process creates a closed control loop, in which target variables for the prepared gas are defined based on an analysis of the gas to be prepared, in particular with respect to CO content and CH 4 content, and potentially also with respect to H 2 content and CO 2 or H 2 O content, wherein they are reached by varying the quantities of individual unburned gas components fed to the preparation chamber, and monitored and readjusted as needed by analysing the prepared gas. [0120] The corresponding device for this control loop for assuring the quality of the prepared gas consists of gas composition analysers, in particular for gas components CO and CH 4 , but also CO 2 and H 2 , and potentially H 2 O and/or O 2 . Sensors for determining the quantity and temperature of the gas entering the preparation chamber for preparation and exiting the preparation chamber after prepared, controllable metering valves and rate meters for the unburned gases fed into the preparation chamber, as well as a programmable control system for processing the measuring data, calculating the target variables, and relaying the control signals to the actuators, such as valves, etc. [0121] In this way, a treatment stimulus that increases the effectiveness of the heat treatment is created immediately in the treatment chamber according to at least one of the parameters such as temperature, CO content or pressure through integrated monitoring/measurement/control/adjustment of the atmosphere in the treatment chamber or the temperature of the process gas. In this context, the monitoring/measurement/control/adjustment is further supported in the treatment chamber by at least one of the parameters, such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere. [0122] With this method, it is advantageously possible to add air from a cold area to at least one treatment medium of the process gas that is to be prepared. [0123] The method as a whole is characterized in that the prepared process gas is extracted from the treatment chamber again and fed back into the external module, prepared again as before, and forwarded back to the treatment chamber of the industrial furnace. [0124] For the accelerating and compressing circulating/mixing motion of at least one of the treatment media in the process gas, air is fed from a cold area to at least the one compressor located in the external module. [0125] For control and adjustment, software is used that adds another treatment medium, for example a reagent gas, by segments in pulsed, timed, and/or constant quantities from at least one treatment medium of the process gas, for example the atmosphere in the treatment chamber. [0126] In this way, if carburisation causes the concentrations of CO 2 , H 2 O and O 2 to increase and the C level to fall in the heating chamber, this diluted gas is fed back into the preparation chamber, which is separate and thus locally isolated from the heating chamber. [0127] Here, the C level is enriched by the addition of finely metered quantities of natural gas, initiating the reactions described earlier, such as [0000] 2CH 4 +O 2 2CO+4H 2 [0000] CH 4 +CO 2 2CO+2H 2 [0000] CH 4 +H 2 O CO=CO+3H 2 [0000] and reducing the concentrations again. [0128] However, natural gas is only added to the preparation chamber if the C potential falls. While enrichment is not required, no natural gas is added. Natural gas only needs to be introduced to enrich the mixture, and then in the smallest quantities, when the C potential falls as a result of carburisation (and not due to flushing, as was previously the case). In the ideal operating state, therefore, carbon in the form of natural gas only needs to be added in a quantity necessary for carburising the part, in order to lower the C level, air may be introduced. [0129] No additional protective gas generator is required to ensure the process reliability of an industrial furnace, because this function is performed by the external preparation chamber. [0130] The heat treatment process workflow is configured such that, after the heating chamber has been loaded with the batch of materials/workpieces, flushing gasification with protective gas generated by the system is carried out for a defined initial period so that the desired furnace atmosphere is restored as quickly as possible. For this, a natural gas/air mixture is fed into the preparation chamber, a solenoid valve to a burn-off system equipped with a pilot burner is opened, and the furnace is flushed with protective gas. After the flushing period, all valves on the burn-off system area closed and recirculation is started. In this way, the protective gas is recirculated to the external preparation chamber of the separate module and may be adjusted to the desired C level and prepared by the metered addition of natural gas. [0131] The fully prepared protective gas can also be introduced into the heating chamber via a plurality of points as a multipoint feed inside the heating chamber. In this way, is it possible to establish a homogeneous gas atmosphere more quickly than was the case with conventional methods. In addition, the geometry of the treatment chamber may be optimised for a given application by using a selectable single-point or multi-point feed system. [0132] For example, if atmospheric heat treatment furnaces are equipped with a strong internal gas circulation system and given a multi-point feeding process, the reaction gas to be prepared can be siphoned out of the treatment chamber, and the gas prepared in the preparation chamber can be returned to the treatment chamber via a single interface in the form of a coaxial dual pipe with an inner pipe that is somewhat longer than the outer pipe. [0133] The reaction gas to be prepared is here advantageously siphoned off via the inner pipe, while the prepared gas is returned via the outer pipe. [0134] As a result, minimal structural changes, if any, are normally required when retrofitting existing heat treatment furnaces with the gas preparation system according to the invention. It is in this way that the overall decisive advantage of the method, as described in the preceding, becomes evident. The protective gas is generated and enriched separately from the batch, that is to say the batch is constantly exposed to a homogeneous gas atmosphere. No streaks or inconsistencies occurred due to the introduction of natural gas into the heating chamber for enrichment, so that undesirable local over-carburisations, such as may be caused by non-uniform carburisation to due to methane dissociation, are precluded. [0135] The CO content is not constant during treatment because natural gas is added to compensate for the effects of carburising. Accordingly a CO analyser is needed to enable adjustment. If the CO content falls below a minimum value, the option still remains to increase the CO content again with a brief flushing phase. In the course of the process, the concentrations of CO and H 2 initially fall and rise during the over-carburisation phase, because until this time a relatively large quantity of CH 4 has been needed initially to saturate the surface of the parts being treated. [0136] In the process sequence according to the invention, this behaviour is advantageously such that less enrichment is required. During the diffusion phase, in which the need for enrichment gas is the smallest, the concentrations are thus approximately equivalent to the normal reaction compound. [0137] Accordingly, a practically self-regulating, adaptive gasification system has been created in which natural gas is only added as an enrichment agent when the C potential of the atmosphere falls because of carburisation of the parts, and not due to flushing losses or such other causes. [0138] The circular process for making significant economies in process gas, as represented by the ideal objective illustrated in FIG. 2 , is fulfilled with the invention. [0139] The external module associated with the performance of the method, and which is to be used preferably, essentially includes the following in a housing: a) a closable preparation chamber with a catalyst and temperature adjustment device for preparing the process gases, which is via one detachable and sealable inflow line for a prepared process gas to be introduced into the treatment chamber of the industrial furnace and one sealable outflow line for a treatment medium from an area or from the treatment chamber of the industrial furnace, b) a blower-type compressor with drive unit attached to the preparation chamber and functionally integrated with the inflow line, c) equipment for measuring the inflow of treatment media of the process gas, the pressure in the treatment chamber, the rotating speed of the compressor and the temperature of the catalysts, which equipment is connected functionally to the treatment chamber of the industrial furnace, the preparation chamber and the compressor, and d) an assigned switching unit for controlling and adjusting parameters such as the pressure, temperature, the volume flow of the process gas to be prepared in the preparation chamber for the purpose of feeding the treatment media, feeding the prepared process gas into the treatment chamber of the industrial furnace, and the C level. [0144] From the point of view of someone skilled in this field, these reactions are to be understood such that of course air and the cited hydrocarbon gas may also be used to adjust the carbon potential. This means that at quantity of air is introduced if the C potential is to be lowered; on the other hand, a hydrocarbon gas is introduced if it is desired to raise the C level. [0145] The fundamentally new gas preparation process corresponding to the preliminary stage of the invention was already defined in the DE 10 2008 029 B1 cited at the outset. This process involves reducing the gas components CO 2 and H 2 O to CO and H 2 in a preparation chamber not separately arranged there by means of unburned gases fed into the preparation chamber, which essentially consist of hydrocarbons, if necessary with certain percentages of an oxidizing gas, such as O 2 , CO 2 , etc. [0146] To this end, the gas to be prepared and the unburned gases must be heated to a reaction temperature necessary for the conversion, and a metal catalyst must be present to accelerate the process. Depending on the metal of the used catalyst, the necessary conversion temperatures range from 800° C. to 1250°. [0147] Since no prepared reaction gas is often available at the start of the process in heat treatment furnaces operated with reaction gases, it must first be generated for the respective location. [0148] In an especially advantageous embodiment of the preparation chamber, the latter can also be used to generate the reaction gas required by the heat treatment furnace. [0149] In this reaction gas generating process, the preparation chamber is operated similarly to an endothermic atmosphere generating system (like an endothermic gas generator), specifically in such a way as to entirely or partially prevent the supply of gas from the treatment chamber into the preparation chamber (by stopping or decelerating the circulating fan or closing the corresponding line valve), raise the quantities of hydrocarbons and oxidizing gases metered in the preparation chamber based on the required amount of endothermic gas to be generated, and analyse and regulate the quality of the generated endothermic reaction gas, relaying the endothermic gas generated in this way to the furnace in a hot or cooled state. [0150] After the treatment chamber of the furnace according to the invention has been scoured for the corresponding requisite period of time with the endothermic reaction gas generated in the preparation chamber, the furnace is ready for thermochemical heat treatment, and the preparation chamber can be switched from the gas generating process to the gas preparation process. [0151] In an especially advantageous way, this enables the configuration and combined utilization of the preparation chamber for the gas generation and gas preparation of reaction gases. [0152] In order to satisfy these requirements, the preparation chamber is designed to be fire-resistant and gastight, and provided with a heater and temperature controller. [0153] In order to accelerate the gas reactions described above, metals known from the gas generating systems, in particular nickel, are used as the catalyst material. [0154] The performance of the preparation chamber with respect to quantity and quality of preparation or of the generated reaction gas depends on the reaction temperature level, in particular on the size of the catalyst surface. Catalysts of the kind used for scrubbing the exhaust gas in passenger car engines yield catalysts that perform at an especially high level, while at the same time exhibiting a compact structure. [0155] The overall scope of the invention may be represented in this context by a detailed explanation of its optional variants: [0156] The key to the method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnace treatment chambers is that the respective process gas is able to be prepared at temperatures that are independent of the temperature in the treatment chamber, in a process separate from the heat treatment process in the treatment chamber, and in a temperature range significantly lower than the temperatures in the heating chamber, up to a temperature of about 1250° C. [0157] The process gas is usually a process gas that is consumed after the heat treatment process or thermochemical treatment, and it is prepared in the separate process. [0158] Process gases are enriched and generated separately in a preparation step according to at least one of the following reaction equations, for example, [0000] 2CH 4 +O 2 2CO+4H 2 [0000] CH 4 +CO 2 2CO+2H 2 [0000] CH 4 +H 2 O CO+3H 2 [0000] or an equation having equivalent effect. [0159] After a carburising or heat treatment process step according to one of the following reaction equations, for example, [0000] 2CO→C+CO 2 [0000] CO+H 2 →C+H 2 O [0000] CO→C+0.5O 2 [0000] or an equation having equivalent effect, the used process gas is returned to the treatment chamber. [0160] The sequence of the preparation step and the process steps of heat treatment, thermochemical treatment or carburisation is carried out in a closed circuit via the preparation step and in a preparation chamber having a catalyst and temperature adjustment device that is separate from the treatment chamber of the industrial furnace. [0161] For this, a module may be used that includes the preparation chamber with the catalyst and temperature adjustment device, wherein an external module is particularly advantageous for industrial furnaces that need to be retrofitted. [0162] On the other hand, a module that is integrated in the industrial furnace may also be used, particularly for new installations. The module may be connected to the treatment chamber via lines. [0163] The used process gas may be extracted from the treatment chamber and returned to the preparation chamber via an outflow line, and the prepared process gas may be compressed and fed into the treatment chamber from the preparation chamber via an inflow line. [0164] At least one process gas compressor is used to accelerate the closed circuit of extracting the used process gas and feeding the prepared process gas back, and to at least homogenise and compress it, and transport it with a higher level of activation. At least one process gas compressor is functionally integrated in the preparation step, and a turbocharger may be used as the process gas compressor. A piston compressor may be used as the process gas compressor. [0165] In this way, the preparation of process gases for heat treatments of metallic materials/workpieces in industrial furnace treatment chambers, which process gas includes at least a first treatment medium as a protective gas, which may include the components carbon dioxide, oxygen and steam in addition to the components carbon monoxide, hydrogen and nitrogen, and a second treatment medium as a reagent gas, which initiates a thermochemical process, may proceed as follows: a) In the preparation step, the process gas is prepared with respect to at least one of the properties thereof that are essential for heat treatment, such as chemical properties, temperatures, pressures or flow speeds, in a separate module outside of the treatment chamber and the industrial furnace, and in this step b) the components, such as carbon dioxide, oxygen and steam react catalytically with a hydrocarbon as a reagent gas to yield carbon monoxide and hydrogen, and after this reaction the protective gas has an adjusted C potential, wherein c) the C potential is adjusted with respect to at least one of the parameters such as temperature, pressure and flow speed depending on the conditions in the treatment chamber and the prepared process gas, having been compressed, homogenised and accelerated is fed into the treatment chamber via the process gas compressor and directed and controlled with respect to the materials/workpieces via a single-point or multipoint feed system, and d) in the treatment chamber at least one treatment medium of the process gas is recirculated and recovered for preparation in the separate module. [0172] Air from a cold area may be added to the treatment media of the process gas being prepared. [0173] The used process gas or at least one of its treatment media is extracted from the treatment chamber and fed back into the treatment chamber after it has been prepared. [0174] At least one process gas compressor is used for the flow accelerating and compressing circulation of at least one treatment medium of the process gas being prepared, with which air from a cold area may be mixed for cooling. The process gas compressor may be driven by a blower. [0175] The compressing, mixing/homogenising and/or accelerating transport of the process gas is directed towards the materials/workpieces of the batch to be treated via the single-point or multipoint feed system, which may be adapted to the treatment chamber of the respective furnace type. Flow optimising guidance devices are able to assist the directed transport of the process gas towards the workpieces/materials. [0176] It is conceivable for the process gas or at least one of the treatment media to be diverted from at least one other industrial furnace or treatment chamber. [0177] In order to control and adjust as well as monitor the process atmosphere in the treatment chamber of the industrial furnace or the temperature of the process gas, equipment having at least one of the requisite elements such as probes, analysers and sensors is used to measure the temperature and CO content as well as the pressure in the treatment chamber and at least one further parameter, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in the treatment chamber, and subsequently to regulate the preparation of the process gas in the preparation chamber and to control the inflow or outflow thereof according to the reconditioning time for at least one treatment medium from the treatment chamber. [0178] The reconditioning time may be controlled according to at least one of the parameters such as a) rotating speed of the compressor and b) number of times the process gas passes through the preparation chamber with the catalyst without interruption. [0181] Software may be used for controlling and adjusting by segments at least one treatment medium of the process gas to be prepared for the atmosphere in the treatment chamber by at least a pulsed, timed or constant addition of at least one of the treatment media as reagent gases. [0182] At least one treatment medium of the process gas may be used for several industrial furnaces or treatment chambers. [0183] Partial mass flows of the process gas may be produced and controlled in at least one process step. [0184] In order to carry out the method, the device includes a closable preparation chamber equipped with a catalyst and temperature adjustment device for preparing the process gases, the functionally integrated process gas compressor, equipment functionally connected to the treatment chamber of the industrial furnace, the preparation chamber and the process gas compressor for measuring the inflow of the process gas treatment media, and a switching unit for controlling and adjusting at least one of the parameters of the process gas being prepared in the preparation chamber for the purpose of feeding treatment media, feeding the prepared process gas into the industrial furnace treatment chamber, and the C level, and for extracting at least one of the treatment media. [0185] The device may be configured as a separate module including a) a housing with the closable preparation chamber, the catalyst and the temperature adjustment device, which housing is equipped with at least one detachable and sealable inflow line each for the prepared process gas or components thereof as treatment media to be introduced into the industrial furnace treatment chamber, and one outflow line for at least one treatment medium from an area of from the treatment chamber of the industrial furnace, b) equipment for measuring the inflow of the process gas treatment media, the pressure in the treatment chamber, the rotating speed of the process gas compressor, the actuation of elements such as valves in order to create a partial mass flow of the process gas, and the temperature of the catalyst, and c) the switching unit for controlling and adjusting the parameters such as pressure, temperature, volume flow of the process gas to be prepared in the preparation chamber, wherein the process gas compressor may be attached to the treatment chamber. [0189] It is preferably also possible to attach the process gas compressor to the preparation chamber. [0190] It is conceivable for the module to be configured as a separate module integrated in the industrial furnace, and in this case the module may also be designed functionally as a retort. [0191] Preferably for retrofits according to the invention, it is designed as separate module that may be connected externally to an existing industrial furnace. [0192] The respective module may be lined with a ceramic material. [0193] The equipment is equipped in detail with at least one of the following elements: d) probes, analysers and sensors for measuring a temperature, a CO content and a pressure in the treatment chamber, and at least one more of the parameters such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in the treatment chamber, e) a switching unit ( 2 . 5 ) as a control and adjustment device for preparing the process gas ( 3 ) in preparation chamber ( 2 . 2 ), and controlling the inflow or outflow according to the reconditioning time, and f) means for controlling a residence time, cycles or a partial mass flow of the process gas ( 3 ) in preparation chamber ( 2 . 2 ) or treatment chamber ( 1 . 1 ). BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0197] In the drawing: [0198] FIG. 1 is a diagrammatic representation of a carburisation reaction on the surface of a part and secondary reactions in the furnace atmosphere according to the described prior art, [0199] FIG. 2 is a diagrammatic representation of the reactions known previously in principle in a treatment and preparation chamber designed in accordance with DE 10 2008 029 001.7-45 including recirculation of the prepared gas, and [0200] FIG. 3 is a diagrammatic representation of an example of an industrial furnace operated according to the method and using the device according to the invention for preparing process gases. DETAILED DESCRIPTION OF THE INVENTION [0201] FIG. 3 is a diagrammatic representation of a plant designed according to the invention including for example an industrial furnace 1 that is suitable for retrofitting. Industrial furnace 1 has a treatment chamber 1 . 1 , a multipoint feeder as a multipoint feed system 1 . 2 , and a quenching area 1 . 3 . [0202] Even though a single-point feed is essentially possible, the advantages offered by a multi-point feed 1 . 2 for siphoning the reaction gas to be prepared from the treatment chamber 1 . 1 and returning the gas prepared in the preparation chamber 2 . 2 to the treatment chamber 1 . 1 are here to be realized by using an interface in the form of a coaxial dual-pipe with an inner pipe that is somewhat longer than the outer pipe, and by siphoning the reaction gas to be prepared via the inner pipe, and returning the prepared gas via the outer pipe. [0203] A treatment chamber circulation system 1 . 4 is arranged above treatment chamber 1 . 1 . [0204] An inflow line 1 . 5 for a process gas 3 enters treatment chamber 1 . 1 , and an outflow line 1 . 6 for extracting at least a first treatment medium 3 . 1 of process gas 3 exits treatment chamber 1 . 1 . [0205] An external module 2 consists of a housing 2 . 1 with a preparation chamber 2 . 2 , which is equipped with a catalyst 2 . 2 . 1 and a temperature adjustment device 2 . 2 . 2 . Preparation chamber 2 . 2 is connected to treatment chamber 1 . 1 via inflow line 1 . 5 for the process gas 3 . A process gas compressor 2 . 3 , which may be in the form of a turbocharger for example, is arranged before preparation chamber 2 . 2 in outflow line 1 . 6 —primarily in order to extract a first treatment medium 3 . 1 of process gas 3 from treatment chamber 1 . 1 more quickly. Process gas compressor 2 . 3 also ensures that process gas 3 is highly compressed during preparation in preparation chamber 2 . 2 , and that the prepared process gas 3 is forwarded to treatment chamber 1 . 1 in a highly compressed state. [0206] In addition, the preparation chamber 2 . 2 can be designed to be fire-resistant and gastight, and provided with a second heater and temperature controller. [0207] In order to accelerate the gas reactions, metals, in particular nickel, are used as the material for the catalyst 2 . 2 . 1 , wherein the use of the catalyst 2 . 2 . 1 has been proven effective for scrubbing the exhaust gas in passenger car engines. [0208] In order to prevent a reactive breakdown of the introduced process gas 3 after it exits the treatment chamber 1 . 1 or exits the preparation chamber 2 . 2 , the method can be expanded so as to cool this process gas 3 . [0209] To this end, a cooling aggregate 1 . 7 , preferably one designed as a ribbed pipe piece with ducted or induced cooling, is allocated to at least inflow line 1 . 5 or outflow line 1 . 6 . [0210] As an alternative, a reactive breakdown of the introduced process gas 3 can be avoided by heat-insulating or heating the latter after it exits the treatment chamber 1 . 1 or exits the preparation chamber 2 . 2 , so that it achieves its gas temperature. [0211] In the above alternative case, insulation or a first heater would have to be allocated to at least inflow line 1 . 5 or outflow line 1 . 6 . [0212] Equipment 2 . 4 for measuring the supply of treatment media 3 . 1 , 3 . 2 of process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of the process gas compressor 2 . 3 , and the temperature of catalyst 2 . 2 . 1 is connected to treatment chamber 1 . 1 and to a switching unit 2 . 5 for controlling and adjusting the parameters such as pressure, temperature, the volume flow of the process gas 3 to be prepared in preparation chamber 2 . 2 . for the purpose of introducing treatment media 3 . 1 , 3 . 2 and air 3 . 3 , introducing the prepared process gas 3 into treatment chamber 1 . 1 of industrial furnace 1 and the C level, and extracting at least one of treatment media 3 . 1 , 3 . 2 . [0213] The expanded equipment 2 . 4 for an input/output monitoring system designed as a control loop encompasses (not to be shown) Gas composition analysers, in particular for gas components CO and CH 4 , but also CO 2 and H 2 , and potentially H 2 O and/or O 2 , Sensors for determining the quantity and temperature of the gas flowing into the preparation chamber 2 . 2 for preparation and flowing out of the preparation chamber 2 . 2 after prepared, Controllable metering valves and rate meters for the unburned gases fed into the preparation chamber 2 . 2 , and A programmable control system for processing the measuring data, calculating the target variables, and relaying the control signals to the actuators, such as valves. [0218] With this system, the method according to the invention for preparing the respective process gas 3 at temperatures up to about 1250° C. that are uncoupled from the temperature in treatment chamber 1 . 1 , is enriched and generated in a preparation step, in this example according to a reaction equation [0000] 2CH 4 +O 2 2CO+4H 2 [0000] CH 4 +CO 2 2CO+2H 2 [0000] CH 4 +H 2 O CO+3H 2 [0000] and the used process gas 3 is returned to treatment chamber 1 . 1 after a carburisation process step (see FIGS. 1 and 2 ), in this example according to a reaction equation [0000] 2CO→C+CO 2 [0000] CO+H 2 →C+H 2 O [0000] CO→C+0.5O 2 [0219] In this context, it should be noted again it is within the scope of the central idea of the invention that other reactions may also take place according to the composition of the gas components and depending on the corresponding heat treatment methods for preparing the process gas 3 and its consumption as part of the treatment. [0220] The sequence of the preparation step and the process step—as here of the carburisation—takes place in a recirculating circuit. The preparation step is carried out in preparation chamber 2 . 2 which is equipped with catalyst 2 . 2 . 1 and temperature adjustment device 2 . 2 . 2 and separate from industrial furnace 1 but connected to treatment chamber 1 . 1 via lines 1 . 5 , 1 . 6 . [0221] The entire recirculation process also encompasses the generation of the reaction gas to be prepared as a process gas 3 in preparation chamber 2 . 2 . [0222] The following steps are required for this purpose: a) Using the preparation chamber 2 . 2 as a type of endothermic gas generating system, in such a way as to entirely or partially prevent the supply of gas from the treatment chamber 1 . 1 into the preparation chamber 2 . 2 , b) Raising the quantities of hydrocarbons and oxidizing gases metered in the preparation chamber 2 . 2 based on the required amount of endothermic gas to be generated, and analysing and regulating the quality of the generated endothermic reaction gas, and c) Relaying this generated process gas 3 as a quasi-endothermic gas to the treatment chamber 1 . 1 in a hot or cooled state. [0226] After the treatment chamber 1 . 1 has been scoured with the endothermic reaction gas generated in this way in the preparation chamber 2 . 2 , preparations for a thermochemical heat treatment are complete, and the preparation chamber 2 . 2 for the gas generating process is switched over to the actual preparation process. [0227] The used process gas 3 is accelerated out of treatment chamber 1 . 1 through outflow line 1 . 6 exiting treatment chamber 1 . 1 and to preparation chamber 2 . 2 by accelerating process gas compressor 2 . 3 , and after it has been prepared it is returned as prepared and highly compressed process gas 3 out of preparation chamber 2 . 2 through infeed line 1 . 5 to treatment chamber 1 . 1 . This sequence is supported by process gas compressor 2 . 3 significantly with respect to the improved effects according to the invention of gas reactions for generating carburising gas components in the atmosphere, convective gas phase homogenisation for the transport of carbon-containing molecules in the gas phase and to the part, transport by diffusion of carbon-containing molecules through the flow boundary layer to the surface of the part, dissociation and adsorption in terms of splitting of molecules on the surface of the part, absorption of the carbon by the surface of the part, and diffusion of the carbon into the part. [0234] The unburned gases being fed into the preparation chamber 2 . 2 , such as natural gas and air, along with other hydrocarbons and other oxidizing gases, can be adjusted relative to a supplied overall quantity and the ratio of supplied individual quantities, based on the quantity and composition of the gas to be prepared and the desired preparation result. [0235] The composition, flowing quantity and temperature are here measured for the process gas 3 to be prepared after exits the treatment chamber 1 . 1 and before it enters the preparation chamber 2 . 2 , as well as for the prepared gas after it exits the preparation chamber 2 . 2 and before it enters the treatment chamber 1 . 1 . [0236] The entire quantity of the unburned gases fed into the preparation chamber 2 . 2 along with the relative quantities of individual unburned gas components are continuously varied relative to each other in such a way as to yield a process-optimised preparation result. [0237] This sequence forms a closed control loop, in which target variables for the prepared gas are defined based on an analysis of the gas to be prepared, in particular with respect to CO content and CH 4 content, and potentially also with respect to H2 content and CO 2 or H 2 O content. Attainment of target variables is ensured by varying the quantities of individual unburned gas components fed to the preparation chamber 2 . 2 , and monitored and readjusted as needed by analysing the prepared process gas 3 . [0238] For the preparation of process gases 3 , this includes at least first treatment medium 3 . 1 as the protective gas, which includes components carbon dioxide, oxygen and steam in addition to minimum components carbon monoxide, hydrogen, and nitrogen, and second treatment medium 3 . 2 as the reagent gas, which initiates the carburising process. [0241] The processes may be summarised as follows: process gas 3 is accordingly prepared in the preparation step with regard to at least one of the properties thereof that are essential for the heat treatment, such as chemical properties, temperatures, pressures, or flow speeds, separately in external module 2 , outside of treatment chamber 1 . 1 and industrial furnace 1 , in this context, the components such as carbon dioxide, oxygen, and steam react catalytically with a hydrocarbon as a reagent gas to yield carbon monoxide and hydrogen, and following this reaction the protective gas will have an adjusted C potential, the C potential is adjusted according to at least one of the parameters, such as temperature, pressure, and flow speed depending on the conditions in treatment chamber 1 . 1 and having been compressed, homogenised and accelerated the prepared process gas 3 is fed in controlled manner back to treatment chamber 1 . 1 with the aid of process gas compressor 2 . 3 and directed towards the materials/workpieces via, in this case, multipoint feed system 1 . 2 , and at least one treatment medium 3 . 1 , 3 . 2 of process gas 3 is recirculated in treatment chamber 1 . 1 and recovered for preparation in external module 2 . [0246] If necessary, air 3 . 3 from a cold area may be added to treatment media 3 . 1 , 3 . 2 of the process gas 3 to be prepared. [0247] The used process gas 3 or at least one of the treatment media 3 . 1 , 3 . 2 thereof is extracted from treatment chamber 1 . 1 by suction and then returned to treatment chamber 1 . 1 after it is has been prepared. [0248] If necessary, several process gas compressors 2 . 3 may be used for flow-accelerating and compressing circulation of at least one treatment medium 3 . 1 , 3 . 2 of the process gas 3 to be prepared, and air 3 . 3 is also supplied to these from the cold area for cooling purposes. [0249] Process gas compressor 2 . 3 may be driven by a blower, but this is not shown in the figure. [0250] In general, it is advantageous if the compressing, mixing/homogenising and/or accelerating transport of the process gas 3 is directed at the materials/workpieces of the batch that are to be treated via multipoint feed/multiple point feeder system 1 . 2 , which may also be adapted to the treatment chamber 1 . 1 of the respective furnace type. [0251] The prepared process gas 3 may be directed at the workpieces/materials economically via flow optimising guidance devices, but these are not illustrated in the figure. [0252] The method is used advantageously in furnace lines, for example, which are not shown here, if the process gas 3 or at least one of the treatment media 3 . 1 , 3 . 2 is diverted from at least a second industrial furnace 1 . [0253] In order to control and adjust as well as monitor the process atmosphere in treatment chamber 1 . 1 of industrial furnace 1 or the temperature of the process gas 3 , equipment 2 . 4 having at least one of the requisite elements such as probes, analysers and sensors is used to measure the temperature and CO content as well as the pressure in treatment chamber 1 . 1 and at least one more of the parameters, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , and subsequently to regulate the preparation of the process gas 3 in preparation chamber 2 . 2 and to control the inflow into treatment chamber 1 . 1 or outflow of at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 . [0254] Software is used purposefully for control and adjustment of at least one treatment medium 3 . 1 , 3 . 2 of the process gas 3 to be prepared for the atmosphere in treatment chamber 1 . 1 , and it controls or adjusts the pulsed, timed, and/or constant feeing of at least one of the treatment medium 3 . 1 , 3 . 2 , for example the reagent gases, by segments. [0255] The method is capable of being expanded, for example in furnace lines, such that at least one treatment medium 1 , 3 . 2 of the process gas 3 is use for multiple industrial furnaces 1 or treatment chambers 1 . 1 . [0256] It is particularly advantageous if the process of controlling and adjusting as well as monitoring the process atmosphere in treatment chamber 1 . 1 of industrial furnace 1 or the temperature of the process gas 3 , is assured by equipment 2 . 4 having at least one of the requisite elements such as probes, analysers and sensors, which measure the temperature and CO content as well as the pressure in treatment chamber 1 . 1 and at least one more of the parameters, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , and subsequently regulates the preparation of the process gas 3 in preparation chamber 2 . 2 and controls the inflow or outflow thereof according to the reconditioning time for at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 . [0257] In this context, the reconditioning time is controlled according to at least one of the parameters such as a) rotating speed of the compressor and b) number of times the process gas 3 passes through preparation chamber 2 . 1 with catalyst 2 . 2 without interruption. [0260] Accordingly, the device for carrying out the method as has already been described above with an external module 2 includes a) the closable preparation chamber 2 . 2 with catalyst 2 . 2 . 1 and temperature adjustment device 2 . 2 . 2 for preparing the process gases 3 , which is via one detachable and sealable inflow line 1 . 5 for the prepared process gas 3 or components thereof such as treatment media 3 . 1 , 3 . 2 to be introduced into treatment chamber 1 . 1 of industrial furnace 1 , and outflow line 1 . 6 for at least one treatment medium 3 . 1 , 3 . 2 from an area or from the treatment chamber 1 . 1 of industrial furnace 1 , b) the blower-type compressor 2 . 3 with drive unit attached to and functionally integrated with preparation chamber 2 . 2 , and c) equipment 2 . 4 for measuring the inflow of treatment media 3 . 1 , 3 . 2 of the process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of process gas compressor 2 . 3 , and the temperature of catalyst 2 . 2 . 1 , which equipment is connected functionally to treatment chamber 1 . 1 of the industrial furnace, preparation chamber 2 . 2 , and process gas compressor 2 . 3 , d) switching unit 2 . 5 for controlling and adjusting parameters such as pressure, temperature, volume flow of the process gas to be prepared in preparation chamber 2 . 2 for the purpose of feeding treatment media 3 . 1 , 3 . 2 , feeding the prepared process gas 3 into treatment chamber 1 . 1 of industrial furnace 1 , and the C level, as well as extracting at least one of the treatment media 3 . 1 , 3 . 2 . [0265] In this example, external module 2 is constructed as a housing with closable preparation chamber 2 . 2 , catalyst 2 . 2 . 1 , and temperature adjustment device 2 . 2 . 2 . Housing 2 has at least one detachable and sealable infeed line 1 . 5 each for the prepared process gas 3 or the components thereof, such as treatment media 3 . 1 , 3 . 2 , to be introduced into treatment chamber 1 . 1 of industrial furnace 1 , and one outflow line 1 . 6 for at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 of the industrial furnace or an area thereof. [0266] Equipment 2 . 4 is to be designed for measuring the inflow of treatment media 3 . 1 , 3 . 2 of the process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of process gas compressor 1 . 4 , 2 . 3 and for actuating elements such as valve to create a partial mass flow of the process gas 3 , and the temperature of catalyst 2 . 2 . 1 . [0267] Switching unit 2 . 5 must be provided for controlling and adjusting parameters such as pressure, temperature, volume flow of the process gas 3 to be prepared in preparation chamber 2 . 2 . [0268] A turbocharger may be used as the process gas compressor 1 . 4 attached to treatment chamber 1 . 1 . [0269] For special new constructions, separate module 2 may be designed as a module integrated in industrial furnace 1 , though this is not shown here, and such a configuration as a retort is conceivable. [0270] In the example presented here, a preferred illustration of separate module 2 is represented as a module that may be connected to industrial furnace 1 externally. [0271] For module 2 a lining with a ceramic material may be used, such as is known from the prior art described in the introduction. [0272] Finally, the device includes the equipment 2 . 4 indicated previously, having at least one of the following elements: a) probes, analysers and sensors for measuring a temperature, a CO content and a pressure in treatment chamber 1 . 1 , and at least one more of the parameters such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , b) switching unit ( 2 . 5 ) as a control and adjustment device for preparing the process gas 3 in preparation chamber 2 . 2 , and controlling inflow or outflow according to the reconditioning time, and c) means for controlling a residence time, cycles or a partial mass flow of the process gas 3 in preparation chamber 2 . 2 or treatment chamber 1 . 1 . LEGEND [0000] 1 =Industrial furnace 1 . 1 =Treatment chamber 1 . 2 =Multipoint feed 1 . 3 =Quenching area 1 . 4 =Treatment chamber circulating system 1 . 5 =Inflow 1 . 6 =Outflow 1 . 7 =Cooling aggregate 2 =Module 2 . 1 =Housing 2 . 2 =Preparation chamber 2 . 2 . 1 =Catalyst 2 . 2 . 2 =Temperature control device 2 . 3 =Process gas compressor 2 . 4 =Equipment 2 . 5 =Switching unit for control and adjustment 3 =Process gas 3 . 1 =First treatment medium 3 . 2 =Second treatment medium 3 . 3 =Air

In a method and with a device for preparing process gases ( 3 ) for heat treatments of metallic materials/workpieces, the respective process gas ( 3 ) is to be fed into at least one treatment chamber ( 1.1 ) in an industrial furnace ( 1 ) having been practically fully prepared, homogenised and heated, and the method is to be carried out both with newly built and particularly with already existing installations of industrial furnaces ( 1 ) with the aid of the device, wherein the process gas ( 3 ) is prepared with compression at temperatures uncoupled from the temperature in the treatment chamber ( 1.1 ), in a process separate from the heat treatment process in the treatment chamber ( 1.1 ), and in a temperature range up to about 1250° C., and is rendered usable for economical and low-emission heat treatment (FIG. 3 ).

BACKGROUND [0001] The present invention relates generally to integrated circuit memory devices and, more particularly, to a method and apparatus for automatically adjusting the pull-up margin of a match line circuit used in conjunction with a content addressable memory (CAM). [0002] A content addressable memory (CAM) is a storage device in which storage locations are identified by their contents, not by names or positions. A search argument is presented to the CAM and the location that matches the argument asserts a corresponding match line. One use for such a memory is in dynamically translating logical addresses to physical addresses in a virtual memory system. In this case, the logical address is the search argument and the physical address is produced as a result of the dynamic match line selecting the physical address from a storage location in a random access memory (RAM). CAMs are also frequently used for Internet address searching. [0003] A conventional CAM array 1 having n-bit words is shown in FIG. 1 to include a row of n CAM cells 10 coupled to an associated word line WL. Each CAM cell 10 includes a latch, formed by CMOS inverters 12 and 14 , for storing a bit of data. Opposite sides of the latch are coupled to associated complementary bit lines BL and BL bar via pass transistors 16 and 18 , respectively, where each transistor has a gate coupled to the associated word line WL. The output terminal of the inverter I 2 is coupled to the gate of an NMOS pass transistor 20 , and the output terminal of the inverter I 4 is coupled to the gate of an NMOS transistor 22 . Transistor 20 is coupled between the associated bit line BL and the gate of an NMOS pull-down transistor 24 , and transistor 22 is coupled between the associated complementary bit line BL bar and the gate of pull-down transistor 24 . Pull-down transistor 24 is coupled between ground potential and a match line ML associated with the CAM word formed by the cells 10 . A PMOS pull-up transistor 26 is coupled between a supply voltage V DD and the match line ML. [0004] In the configuration of FIG. 1, the pull-up transistor 26 has a gate tied to ground potential and, therefore, remains in a conductive state. A conventional buffer 28 is coupled in series between the match line and an associated sensing circuit (not shown). During compare operations, the word line WL associated with the CAM word is grounded to turn off the pass transistors 16 and 18 associated with each CAM cell 10 . Comparand bits to be compared with the data bits Q stored in the CAM cells 10 are provided to the associated bit lines BL, while the respective complements of the comparand bits are provided to the associated complementary bit lines BL bar. For each CAM cell 10 , if the comparand bit matches the data bit Q stored therein, the gate of the corresponding pull-down transistor 24 is driven with a logic low signal via transistors 20 or 22 , thereby maintaining the pull-down transistor 24 in a non-conductive state. If, on the other hand, the comparand bit does not match the data bit Q stored in the CAM cell 10 , the gate of the corresponding pull-down transistor 24 is driven with a logic high signal via transistors 20 or 22 , thereby turning on the pull-down transistor 24 . When conductive, the pull-down transistors 24 pull the match line toward ground potential. [0005] Thus, if just one of the comparand bits do not match their corresponding data bits Q stored in the CAM cells 10 , the match line ML will be pulled to a logic low state (i.e., ground potential). Conversely, if all of the comparand bits match their corresponding data bits Q, the match line ML remains at the supply voltage V DD (i.e., a logic high state). In response to the voltage level on the match line ML, the buffer 28 provides to an associated sense circuit (not shown) an output signal indicative of whether all bits of the comparand word match all corresponding bits of the CAM word. [0006] One disadvantage of the above described CAM configuration results from the fact that during a standby mode, DC current will flow through the match line circuit unless the bitline nodes (BL, BL bar) are precharged low. Otherwise, the path to ground potential results in significant power dissipation which, in turn, undesirably increases as the size and/or density of the CAM increases. On the other hand, the use of additional circuitry to precharge the bitline pairs also have negative impacts on device size and cost. BRIEF SUMMARY [0007] The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a method for determining a desired operating impedance for a computer memory circuit, the computer memory circuit having a plurality of discrete, selectively adjustable impedance values associated therewith. In an exemplary embodiment of the invention, the method includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. One of the binary count values represents a first impedance value which causes the reference circuit to change from the first state to the second state, and the other binary count value represents a second impedance value which causes the reference circuit to change from the first state to the second state. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values. [0008] In a preferred embodiment, the lower of the stored pair of binary count values is adjusted by subtracting a predetermined, fixed value therefrom so as to create a buffered count. The buffered count is then used in applying the desired operating impedance to the operating circuit. BRIEF DESCRIPTION OF THE DRAWINGS [0009] Referring to the exemplary drawings wherein like elements are numbered alike in the several Figures: [0010] [0010]FIG. 1 is a schematic diagram of a CAM cell array configured to an existing match line circuit having a single pull-up device; [0011] [0011]FIG. 2 is a schematic diagram of a low-power match line circuit which may be implemented as an alternative to the circuit of FIG. 1; [0012] [0012]FIG. 3 is a schematic diagram of a low-power match line circuit having a self-adjusting pull-up margin, in accordance with an embodiment of the invention; [0013] [0013]FIG. 4 is a truth table which illustrates the relative pull-up strength combinations of the pull-up devices shown in FIG. 3; [0014] [0014]FIG. 5 is a schematic diagram of a reference circuit used in conjunction with the circuit shown in FIG. 3, in accordance with an embodiment of the invention; [0015] [0015]FIG. 6 is a block diagram illustrating functional relationship between the reference circuit of FIG. 5 and the circuit of FIG. 3, as well as the generation of a buffered count to be inputted to the circuit of FIG. 3; and [0016] [0016]FIG. 7 is a timing diagram illustrating the interrelationship between external clock signals and signals generated by the reference circuit of FIG. 5. DETAILED DESCRIPTION [0017] Referring initially to FIG. 2, there is shown a schematic diagram of one possible embodiment of a low-power, match line circuit 200 for a CAM sense amplifier. Match line circuit 200 replaces pull-up PFET 26 and buffer 28 of FIG. 1. For ease of description, only one CAM cell is depicted in FIG. 2. Match line circuit 200 includes pull-up PFET T 4 coupled to a voltage supply V DD and a pull-down NFET T 6 connected to ground. The gates of both T 4 and T 6 are coupled to an ENABLE signal which is initially biased at logic high (e.g., at V DD potential) and which goes to logic low (e.g., at ground potential) during a search or compare operation. In addition, the drains of T 4 and T 6 are coupled to match line ML and thereby define a node labeled MATCH in FIG. 2. [0018] The ENABLE signal is also coupled to an inverter I 1 which, in turn, has an output thereof connected to the gate of pull-up PFET T 5 . Another pull-down NFET T 8 has its drain connected to the drain of T 5 , thereby defining a node labeled FLOAT, which is described in further detail hereinafter. The gate of T 8 is further connected to the MATCH node. Finally, a second inverter I 2 has an input connected to the FLOAT node and an output which defines a node labeled HIT. [0019] The operation of the match line circuit 200 is understood with reference to the following description. In between search (compare) operations, ENABLE is biased at logic high, as stated earlier. Thus, NFET T 6 is rendered conductive, pulling MATCH to ground. As a result, SL and SL bar may remain in their previous state, thereby eliminating the power required to precharge them. Further, the conductive state of T 6 prevents any DC current flowing during a standby mode. This is in contrast to the circuitry shown in FIG. 1, wherein the match line is biased to V DD prior to a data comparison operation, and BLIBL bar must be switched to ground in order to eliminate a DC path. [0020] It will also be noted that, prior to a search operation, the output of 11 is low, thereby rendering PFET T 5 conductive and charging FLOAT to V DD (since T 8 is switched off by the bias on MATCH). The output of inverter I 2 , therefore is low, and there is no “hit signal” on HIT. [0021] During a search, ENABLE is switched to low and a comparand data bit (with associated complement) is applied to the array cell through search lines SL and SL bar. Once ENABLE goes low, T 6 is turned off and T 4 is rendered conductive, attempting to pull MATCH up toward logic high. In the meantime, the output of inverter I 1 switches from low to high, thereby turning off T 5 and causing the FLOAT node to “float” at a high voltage (until such time as T 8 might become conductive). So long as FLOAT remains charged high, the output at HIT will remain low, signifying a data match has not yet occurred. [0022] In the event that a data match occurs (i.e., each bit in the stored CAM word matches each corresponding bit in the comparand word), none of the pull-down NFETs associated with each cell will be activated and thus will not prevent T 4 from pulling MATCH up toward high. During this time, the voltage at MATCH will rise asymptotically to a voltage level determined by the relative strengths of T 4 and the pull-down NFETs in the cells. Once the voltage level at MATCH reaches the threshold value of T 8 , T 8 will turn on and discharge FLOAT to ground. In turn, HIT will then be switched from low to high by inverter I 2 , thereby signaling a data match. [0023] However, if one or more of the comparand data bits do not match the corresponding stored data bits, there will be at least one pull-down NFET opposing the pull-up of T 4 . Accordingly, the voltage value at MATCH will be kept below the threshold value of T 8 so as not to discharge FLOAT and falsely indicate a hit (data match) condition. In the case of a “marginal miss” scenario where there is only one mismatched bit (and thus only one pull-down path activated), the conductivity of T 4 could be just strong enough so as to overcome the pull-down of the lone mismatched cell and pull MATCH all the way up to the threshold of T 8 , thereby triggering a false match. Such a condition is not out of the realm of possibility, given the real world of process variations, inaccurate device models and unpredictable operating conditions. Thus, T 4 is designed to be a weak pull-up PFET. [0024] On the other hand, the weaker the pull-up device used, the longer the time it takes for the device to perform its intended function. Since speed is an important consideration in the design of integrated circuit devices, it is therefore desirable to have a match line circuit for a CAM sense amplifier featuring a pull-up device strong enough to avoid a speed penalty while not allowing the asymptotic match line voltage to reach the threshold voltage (V t ) of the pull-down transistor T 8 during a “marginal miss”. Unfortunately, this can be a difficult proposition by using a single transistor (T 4 ) as the pull-up device. [0025] Therefore, in accordance with an embodiment of the invention, a self-adjusting margin circuit for a CAM sense amplifier is disclosed, which provides automatic control of the margin between the asymptotic MATCH node voltage and the NFET V 1 . A preferred approach is to employ a PFET device having a controllable, adjustable pull-up strength responsive to actual operating conditions. [0026] Referring now to FIG. 3, there is shown an improved match line circuit 300 for use in a CAM array. For ease of description, like or equivalent circuit components in circuit 300 are given the same reference designations as in FIG. 2. In circuit 300 , pull-up PFET T 4 (FIG. 2) has been replaced by PFET TO, as well as a parallel group of PFETs T 20 , T 21 , T 22 and T 23 connected thereto. TO acts as a switch which enables T 20 -T 23 , in combination, to determine the specific impedance (and thus the strength) of the pull up path. PFET T 20 remains conductive since the gate thereof is connected to ground, thereby defining a “default” or minimum strength pull-up value for circuit 300 . The remaining PFETs T 21 , T 22 and T 23 are selectively activated by DC control signals SAM 4 , SAM 2 and SAM 1 , respectively, which control signals determine a discrete value for the pull-up path impedance. [0027] Control signals SAM 4 , SAM 2 and SAM 1 , collectively, may be thought of as a three-bit binary word whose value is proportional to the overall pull-up strength of circuit 300 . The PFET device characteristics are chosen such that SAMI is the least significantly weighted bit and SAM 4 is the most significantly weighted bit. FIG. 4 is a truth table illustrating the resulting device pull-up strength versus the specific combination of activated PFETs. As can be seen, the pull-up strength is minimum with only default PFET T 20 being conductive and maximum when all four PFETs are conducting. [0028] It should be understood that the “ 1 ” and “ 0 ” representations shown in the truth table of FIG. 4 represent the conductive state of the PFETs and not the logic level of the voltage applied to the gates thereof. In other words, first entry in the table (1, 0, 0, 0) signifies that T 21 , T 22 and T 23 are each switched off, not that the inputs on control signals SAM 4 , SAM 2 and SAM 1 are all “low” or “logic 0”. On the contrary, because these devices are PFETs, the voltage inputs on control signals SAM 4 , SAM 2 and SAM 1 would actually be high (e.g., V DD ) to render them non-conductive. [0029] Although in the presently disclosed embodiment a three-bit word is used to provide eight discrete pull-up impedance values, it will be understood that additional binary-weighted transistors may be used to provide a finer range of incremental values. [0030] Given the range of adjustable pull-up impedances provided by circuit 300 , the next task then becomes one of dynamically controlling the PFETs (T 21 , T 22 and T 23 ) such that a specific desired pull-up impedance is achieved in view of possible variations in process conditions and operating conditions. Again, it is desired to use the highest pull-up strength which is also within an acceptable range so as not to create false hit indications. [0031] Accordingly, FIG. 5 illustrates a reference circuit 500 which features devices substantially similar to those included within circuit 300 , and which are preferably formed upon the same chip as circuit 300 and the CAM array. However, in contrast to a plurality of circuits 300 associated with the CAM array cells, there need only be a single reference circuit 500 . In effect, reference circuit 500 is used as a “dummy” or test circuit which is self-adjusting so as to determine a desired impedance strength for the pull-up devices included in the actual operating match line circuits 300 . [0032] As with circuit 300 , reference circuit 500 includes a plurality of parallel connected PFET pull-up transistors labeled T 30 , T 31 , T 32 and T 33 , which are analogous to T 20 , T 21 , T 22 and T 23 . T 30 , having its gate connected to ground, provides a minimum pull-up strength value for reference circuit 500 . Similar to circuit 300 , the selectively adjustable PFETs T 32 , T 32 and T 33 are controlled by input signals P 4 , P 2 and P 1 which comprise a three bit binary word. The values of P 4 , P 2 and PI are driven from latches in a counter, described in greater detail hereinafter. [0033] Because reference circuit 500 is not physically connected to a CAM array, but is instead used in conjunction with a “simulated” CAM array, a dummy capacitive load C 0 is connected thereto. The capacitive load C 0 is intended to make the MATCH node capacitance look like a “real” match node having several capacitive loads coupled therewith. In addition, NFETs T 27 and T 28 provide a constant pull-down path which will continuously simulate a “marginal miss” condition where there is only a single CAM cell providing a pull-down path. [0034] In operation, reference circuit 500 performs essentially the same function as the circuits 300 used in the CAM arrays. Instead of being activated by the ENABLE signal, reference circuit 500 is triggered by the rising edge of a clock signal CLKEVAL (described in additional detail later). Recalling that the operation of circuit 300 is triggered by ENABLE going from high to low, an inverter I 3 is connected to CLKEVAL in reference circuit 500 . Thus, when CLKEVAL rises the PFET network will be enabled, attempting to pull the MATCH node up to its asymptotic voltage. [0035] If the initial value of the PFET pull-up strength (provided by T 30 , T 31 , T 32 and T 33 ) is not too strong, FLOAT will not be discharged and, if too strong, FLOAT will be discharged. Since the primary purpose of reference circuit 500 is to determine the counter value (P 4 , P 2 , P 1 ) which provides the strongest pull-up value that will not discharge FLOAT, the next highest pull-up value that does discharge FLOAT should also be determined. Accordingly, the HIT node of reference circuit 500 is further coupled to a latch L 1 which latches the result of an evaluation upon the triggering of clock signal CLKXFER. The output of latch L 1 is a signal labeled DOWN, which signal thus controls the direction of the counter. [0036] By way of example, it will be assumed that the maximum pull-up strength of reference circuit 500 (which does not result in FLOAT being discharged) corresponds to the binary word value <101> applied to inputs P 4 , P 2 and P 1 . Reference circuit 500 will determine this value by having the input values of P 4 , P 2 and P 1 automatically adjusted until the oscillation point is found, regardless of the initial setting of P 4 , P 2 and P 1 . Thus, if upon the initial evaluation, the PFET strength is too strong, this will be reflected by the latch DOWN signal, and the binary value applied to P 4 , P 2 and P 1 is decremented by one bit for this evaluation. This will continue until FLOAT is not discharged, and then the binary value will be incremented by one bit for the next evaluation. [0037] Continuing with the above example, the following is a table which illustrate one possible sequence of reference circuit evaluations (iterations) performed. Again, it will be assumed in this example that the maximum pull-up strength resides at input value <101> and that the initial value on the counter applied to P 4 , P 2 and P 1 is <000>: Counter Value FLOAT DOWN signal result 000 charged increment by one 001 charged increment by one 010 charged increment by one 011 charged increment by one 100 charged increment by one 101 charged increment by one 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one [0038] It will be seen in the above example that the reference circuit 500 has reached an equilibrium state where the float node is oscillating between charged and discharged where PFET pull-up strengths correspond to the 101 and the 110 values. Therefore, circuit 500 determined that the maximum PFET pull-up strength corresponds to the impedance value when T 31 and T 33 are conductive and T 32 is off (T 30 always being on). Reference circuit 500 will determine this point regardless of whether the initial value applied to P 4 , P 2 and P 1 is “too high” or “too low”. [0039] Equally as important is the fact that reference circuit 500 also allows for dynamic changes in maximum allowable PFET pull-up strength during circuit operation. For example, it may be that circuit temperature conditions result in the lowering of maximum allowable PFET pull-up strength. Thus, a continuation of the above table could look as follows: Counter Value FLOAT DOWN signal result 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one 101 discharged decrement by one 100 charged increment by one 101 discharged decrement by one 100 charged increment by one [0040] As can be seen, the oscillation point has now been lowered such that new maximum allowable PFET pull-up strength corresponds to a <100> input at P 4 , P 2 and P 1 . [0041] Finally, FIG. 6 is a block diagram illustrating the generation of the counter value applied to reference circuit 500 , as well as the interaction between the reference circuit 500 and the match line circuits 300 used in the CAM arrays. A clock generator 502 generates the clock signals CLKEVAL and CLKXFER (described above) sent to reference circuit 500 . The rising edge of CLKEVAL begins an evaluation, while the falling edge of CLKEVAL latches the value of HIT and creates the DOWN signal. The interrelationship between the clock signals and the HIT and DOWN signals is illustrated in FIG. 7. [0042] In a preferred embodiment, the clock generator 502 also comprises a clock divider therein such that the evaluation is performed every 64 th system clock cycle. In one aspect, it is assumed that any drifting in operating conditions is relatively slow as compared to the system clock rate. Additionally, a divide-by-64 clock generator helps to conserve power dissipated in the circuit. However, it should be understood that other clock divider ratios (e.g., divide-by-32) may also be implemented. [0043] Referring once again to FIG. 6, it is seen that the DOWN signal generated within reference circuit 500 is sent to an up/down counter 504 which counts up or down by one bit, depending upon the directional value of DOWN. Upon receiving the clock signal CLKEVAL, up/down counter 504 generates the next three-bit count. This new count is then applied back to P 4 , P 2 and P 1 so that, in turn, an increased/decreased PFET pull-up strength is applied for the next evaluation. [0044] At the same time, a first register 506 stores the new count, as well as the count from the previous evaluation. Then, a comparator 508 selects the lower value of the new count and the previous count to correctly identify which of the two stored counts represents the correct PFET pull-up value that does not cause a false hit indication. In effect, comparator 508 and first register 506 act as a filter, producing a stable count since the equilibrium count is oscillating by one (least significant) bit. Because the count identified by comparator 508 represents the maximum PFET pull-up strength allowed for correct CAM circuit operation, an adder 510 is used as a buffer margin. Adder 510 will then subtract a predetermined amount from the “optimal” count, thereby producing a “conditioned” or buffered count. This conditioned count is then stored in a second register 512 and is used to control the actual pull-up PFETs used in the match line circuitry. [0045] The fixed value that the adder 510 subtracts from the count (determined by comparator 508 ) may be chosen based on experience with the system hardware and can be coded within fuses. Assuming, for example, that this fixed value is designed to be a subtraction by 1 bit, than an oscillating count (as in the above example) between <101> and <110> results in comparator 508 identifying <101> as the maximum pull-up strength. The adder 510 would then subtract one bit from this value to produce a conditioned count of <100>. Therefore, <100> is stored in second register 510 and then buffered to the CAM circuitry for use. It is preferred, however, that additional logic be added so that the conditioned count values supplied to the CAM core are not updated during a search operation. [0046] To summarize, reference circuit 500 , in combination with the above-described digital circuitry, provides a reference sense amplifier for a CAM device. The pull-up strength thereof is controlled by a counter that is self-adjusting in order to identify the maximum pull-up strength of a PFET device which will still allow the CAM to function correctly (i.e., no false hit indications). Once the maximum pull-up strength is identified, that value is reduced and buffered so that the actual pull-up value used in the CAM devices is close, but not “too close” to the maximum value. In the event that actual process conditions effect a shift in maximum pull-up strength, this will also be identified and compensated for. [0047] Although the above disclosed invention embodiments have been in the context of content addressable memories, it will be appreciated that the principles herein may be applicable to other memory storage devices. Furthermore, these principles are equally applicable to other types of devices in general where it is desirable to automatically adjust the margin of operating impedances to compensate for process and dynamic operating conditions. [0048] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

A method for determining a desired operating impedance for a computer memory circuit is disclosed, the computer memory circuit having a plurality of discrete, selectively adjustable impedance values associated therewith. In an exemplary embodiment of the invention, the method includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to port collars for use in a tubular string. Specifically, the invention relates to a two-position port collar which can be repeatedly opened and closed and securely retained in each position. 2. Background of the Related Art Port collars typically have a tubular housing which can be made up into a tubular string to form a part thereof. The port collar has a sliding sleeve disposed therein which may be used to selectively communicate fluid flow between an annular area of the well and an interior of the tubing string. In one example, a port collar is installed in a tubular string in a closed position and the tubular string is then inserted into a wellbore, locating the port collar at a predetermined depth in the well. Packing elements are installed above and below the port collar to isolate a specific zone of the annulus. Thereafter, the sliding sleeve of the port collar is remotely opened and the interior of the tubular is placed into communication with production fluid in the annulus. The port collar may also be used to permit fluid flow from the interior of the tubing string into the annulus of a well. For example, in cementing deep wells, a two-part cementing job is often used wherein the lower portion of a casing or liner string is cemented and then, using a port collar, the upper annulus is cemented to avoid hydrostatic pressures present in the lower portion of the annulus. While many port collar designs have been made and used, certain problems exist with current designs. For example, most port collars rely on shear screws or some other type of mechanically shearable connection to unlock the sleeve from an initial position and permit movement of the sleeve to a second position within the collar. In a typical example, the shearable connection holds the sleeve in a closed position and then, when the collar is in the wellbore and ready to be opened, the shearable members are caused to fail with mechanical or hydraulic force. Once the shearable connection has failed, the sleeve is left prone to accidental shifting in the housing, unless it is permanently locked into either an open or closed position. There is a need therefore, for a port collar that does not rely on a shearable connection to lock the sleeve into position within the housing. There is a further need for a port collar that can be repeatedly shifted and locked into the opened and closed positions. There is yet a further need for an easily shiftable port collar that can be used with other port collars in a single tubular string to create a larger assembly for selectively exposing different areas of an annulus to communication with the interior of the tubing string. SUMMARY OF THE INVENTION The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking system for each position comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. One set of mating ratchet teeth are designed to secure the sleeve in an opened position within the housing and a second set of mating ratchet teeth secures the sleeve in a closed position. In one aspect of the invention, the ratchet teeth on the interior surface of the housing are formed on the inner surface of an inwardly biased C-ring disposed in a groove formed in the interior surface of the housing. A plurality of buttons are disposed within apertures formed in the exterior surface of the sleeve and the buttons can be urged in an outward radial direction by a shifting tool disposed within the sleeve. The buttons urge the C-rings into the grooves of the housing and out of engagement with the mating ratchet teeth formed on the surface of the sleeve. In this manner, the sleeve and housing are unlocked from each other and the tool can be shifted to the other position. In another aspect of the invention, cavities and shifting shoulders are formed on the interior of the sleeve opposite each locking system. Corresponding unlocking and detenting formations are formed on a shifting tool including a formation designed to urge the buttons of the sleeve in a radial outward direction. A shifting surface on the shifting tool, corresponding to a shoulder formed on the interior of the sleeve, allows a force to be applied to move the sleeve to a second location in the housing after being unlocked. In another aspect of the invention, several port collars are installed in a tubular string in a wellbore. Thereafter, in order to open and close the port collars, a number of shifting tools are run into the well on a run-in string in a pre-determined, spaced-apart orientation. The shifting tool at the lowest point on the string opens each port collar as it passes therethrough. In order to close the port collars, the string of shifting tools is pulled upwards and the shifting tool designed to close the port collars closes each collar as it passes therethrough. By accurately spacing the shifting tools along the run-in string, the direction of the string can be reversed in order to open a certain port collar while leaving the others in a closed position. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. FIG. 1 is a partial section view showing the port collar of the present invention. in an open position. FIG. 1A is an enlarged view of a locking portion of the port collar of FIG. 1 . FIG. 2 is a partial section view of the port collar in a closed position. FIG. 3 is a perspective, side view of a shifting tool used to open the port collar including an opening portion and a closing portion. FIG. 4 is a section view showing the port collar in the open position with a shifting tool installed therein. FIG. 4A is an enlarged view showing the opening portion of the shifting tool engaged in the sleeve of the port collar. FIG. 5 is a section view showing a collet-like function of the shifting tool. FIG. 5A is an enlarged view thereof. FIG. 6 is a side view of a wellbore showing a plurality of port collars disposed on a string of tubulars. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a side view, partially in section of the port collar 200 of the present invention. The port collar 200 includes a housing 205 , which is typically connected at each end to a tubular string (not shown). The housing 205 includes a plurality of housing apertures 210 formed in a wall thereof and constructed to align with sleeve apertures 212 formed in a wall of a sleeve 206 when the port collar 200 is in an open position as in FIG. 1 . The sleeve 206 is disposed within the housing 205 and is installed therein in a certain rotational orientation which is predetermined and is secured with lock screws or set screws (not shown) between the housing 205 and the sleeve 206 . Axial movement of the sleeve 206 within the housing 205 is limited by stops 215 , 217 formed at each end of the interior of the housing 205 . The stops prevent axial movement of the sleeve 206 within the housing beyond that movement necessary to locate the sleeve 206 in the open or closed position. The port collar 200 includes a first locking system, generally labeled 300 to retain the sleeve 206 in a closed position and a second locking system 301 to retain the sleeve in an open position. In FIG. 1, locking system 301 is engaged and the port collar 200 is locked in the open position with fluid communication possible between the inside and outside of the port collar 200 through aligned apertures 210 , 212 . The sleeve 206 is prevented from axial movement in a first direction by stop 217 and in the direction of the closed position by engaged locking system 301 . Each locking system 300 , 301 includes locking surfaces formed on the perimeter of the sleeve 206 and locking surfaces formed on the inner surface of the housing 205 . The surfaces prevent the sleeve 206 from moving within the housing 205 in one direction. FIG. 1A is an enlarged view showing a portion of engaged locking system 301 . Specifically, the locking surface formed on the sleeve 206 includes ratchet teeth 325 extending around the sleeve perimeter. In the preferred embodiment, the mating locking surface of the housing 205 includes at least one groove 365 formed in the inner surface of the housing with an inwardly biased C-ring 370 disposed therein. On the inside surface of the C-ring 370 , facing the sleeve 206 , ratchet teeth 375 are formed and are designed to interact with ratchet teeth 325 formed on the exterior of the sleeve 206 such that the sleeve 206 is prevented from axial movement in the housing 205 in a first direction when the mating teeth 325 , 375 of the sleeve and the C-ring are engaged. As depicted in FIG. 1A, the engaged ratchet teeth 325 , 375 will move across each other with little resistance in a first direction but will interfere with each other preventing movement in a second direction. Specifically, the design allows the ratchet teeth 325 , 375 to move across each other as the port collar 200 is shifted to the open position shown in FIG. 1 . Thereafter, the interaction of the teeth 325 , 375 prevent the sleeve 206 from moving back towards the closed position. In the open position therefore, the sleeve 206 is prevented from axial movement in one direction by stop 217 acting between the sleeve 206 and the housing 205 and in the opposite direction by the locking system 301 . Interspersed with the ratchet teeth 325 on the outer perimeter of the sleeve 206 are at least one button 335 , one of which is visible in FIG. 1 A. The buttons 335 are housed in countersunk apertures 336 formed in the sleeve 206 and a head portion 337 of each button 335 is retained on a reduced diameter shoulder 338 formed in each aperture. The buttons can be urged outwardly radially by a shifting tool described hereafter. The placement of apertures 336 with the buttons 335 therein correspond to the location of the ratchet teeth 325 formed on the outer surface of the sleeve 206 such that the buttons 335 , when urged outwards, extend out above the ratchet teeth 325 . By urging the buttons outward, the head portion 337 of the buttons move the inwardly biased C-ring 370 back into the groove 365 and out of engagement with the ratchet teeth 325 of the sleeve. In this manner, the locking system 301 is unlocked and the sleeve 206 can be moved axially within the housing 205 . The number of buttons utilized can be increased for redundancy. Additionally, each locking system can utilize multiple locking surfaces. For example, if a particular tool is run through a port collar and one set of buttons is inadvertently urged outwards thereby disengaging a first C-ring, a second C-ring with its locking surface will remain engaged with corresponding ratchet teeth of the sleeve, thereby preventing premature shifting of the port collar. FIG. 2 is a partial section view showing the port collar 200 in a closed position with the sleeve apertures 212 out of alignment with the housing apertures 210 . In the closed position, there is no fluid communication between the interior and exterior of the port collar 200 . As with locking system 301 , locking system 300 includes ratchet teeth formed on the exterior of the sleeve 206 and ratchet teeth formed on the inside surface of a C-ring housed in a groove formed on the inside surface of housing 205 . In the closed position, the sleeve 206 is prevented from movement in a first axial direction by stop 215 and in the direction of the open position by the engaged locking system 300 . Unlocking and shifting of the port collar 200 between the open and closed positions are performed through the use of a shifting tool. FIG. 3 is a perspective view of shifting tool 400 which is comprised of an opening portion 410 and closing portion 450 , each portion having an opposing orientation along the length of the shifting tool. Portions 410 , 450 , when run into the wellbore, are independently seated in the interior of the port collar sleeve 206 . FIG. 3 illustrates the opening portion 410 including a tool oriented to open the port collar 200 and closing portion 450 oriented to close the port collar 200 . The spacing between the opening 410 and closing 450 portions is adjustable depending upon operational conditions and requirements. Each portion 410 , 450 of the shifting tool 400 includes collet-like features with a plurality of slots 436 formed longitudinally within the tool. The slots create fingers 435 therebetween which move in a spring-like manner when force is applied to the surface thereof. In the preferred embodiment, at least four equally spaced fingers 435 are formed around the shifting tool 400 . Considering the opening portion 410 of the tool in greater detail, each finger 435 includes two unlocking formations 412 , 430 designed to interact with corresponding surfaces on the interior of the sleeve 206 . Unlocking formation 430 also serves to move the sleeve 206 within the housing 205 via engagement between surfaces of the formation 430 and the sleeve 206 . Unlocking formations 412 , 430 include upper surfaces 413 , 431 substantially parallel to the surface of finger 435 and three angled surfaces 414 , 415 , 433 . Unlocking formation 430 also includes one shifting surface 432 substantially perpendicular to the surface of finger 435 . The shifting surface 432 provides a means to urge the sleeve 206 from the closed to the open position as described hereafter. A detenting formation 420 has one upper surface 421 substantially parallel to finger 435 and two angled surfaces 422 , 423 . Closing portion 450 similarly includes two unlocking formations 470 , 480 and are detenting formation 460 . As with the opening portion, formations 480 , 470 include surfaces 481 , 471 substantially parallel to the surface of finger 435 and three angled surfaces 483 , 472 , 473 . Additionally, shifting formation 480 includes shifting surface 482 substantially perpendicular to finger 435 . A detenting formation 460 includes an upper surface 461 and also a two surfaces 462 , 463 angled to the surface of finger 435 . Formed in the interior of the sleeve 206 , opposite each locking system 300 , 301 are cavities constructed and arranged to interact with the formations and surfaces of the shifting tool 400 . FIG. 4 is a partial section view of the port collar 200 showing the closing portion 450 of the shifting tool 400 engaged with the corresponding cavities in the sleeve opposite locking system 301 . With the closing portion 450 of the shifting tool 400 inserted, the sleeve 206 may be urged in the direction of stop 215 , mis-aligning the apertures 210 , 212 of the sleeve and housing and closing the port collar 200 . As illustrated in FIG. 4A, an enlarged view of locking system 301 , formations 460 , 470 , 480 of the closing portion 450 of the shifting tool 400 have engaged corresponding cavities of the sleeve 206 . The interior of the sleeve 206 opposite locking system 301 includes two unlocking cavities 430 , 436 and one shifting shoulder 440 constructed and arranged to interact with unlocking formations 470 , 480 and detenting formation 460 formed on the closing portion 450 of the shifting tool 400 . In FIG. 4A, shifting surface 482 of the shifting tool is in contact with shoulder 440 of the sleeve 206 . Surfaces 481 , 471 of formations 470 , 480 have contacted the lower surface 338 of buttons 335 disposed in the sleeve 206 and the buttons have been urged outwards in a radial direction. The head portion 337 of each button 335 has contacted and urged the C-rings 370 into the grooves 365 formed on the interior surface of the housing 205 . In this manner, the ratchet teeth 375 have been moved out of engagement with the mating ratchet teeth 325 (not visible) on the exterior of the sleeve 206 . With the ratchet teeth 325 , 375 out of engagement, force applied against shoulder 440 by shifting surface 482 will cause the sleeve 206 to move axially within the housing 205 . As the sleeve 206 moves into the closed position, axial movement of the sleeve 206 is limited by stop 215 and locking system 301 will prevent axial movement towards the open position, thereby locking the port collar 200 in the closed position. As visible in FIG. 1, there are two cavities 437 , 434 and a shifting shoulder 436 opposite locking system 300 to interact with formations 412 , 430 and shifting surface 432 of the opening portion 410 of the shifting tool 400 . Locking system 300 is disengaged in a similar manner as locking system 301 and those skilled in the art will appreciate that the foregoing description is equally applicable to locking system 300 . FIG. 5 is a partial section view of the port collar 200 having been shifted to the open position by the opening portion 410 of the shifting tool 400 . FIG. 5 illustrates the collet-like movement of the fingers 435 allowing the opening portion 410 of the shifting tool 400 to be urged out of engagement with the sleeve 206 . FIG. 5A is an enlarged view showing the interaction of the various surfaces of the shifting tool 410 , sleeve 206 and housing 205 . After the port collar is shifted to the open position and additional axial movement of the sleeve 206 is prevented by stop 217 , continued force applied to the shifting tool will cause a surface 423 of the detenting formation 420 to contact and move downward across an undercut surface 218 of the sleeve 206 formed below stop 217 . The downward component of force exerted upon surface 423 urges the flexible finger 435 downward until shifting surface 432 is no longer in contact with corresponding shoulder 502 of sleeve 206 . In this manner, the shifting tool 400 can be moved out of engagement with the port collar. Typically, a port collar 200 is placed in a well in the closed position whereby the annular area around the port collar 200 is isolated from the interior of the port collar. In order to open the port collar 200 , a shifting tool 400 is run into the well on a run-in string of tubular. The opening 410 and closing 450 portions of the shifting tool 400 allow the port collar 200 to be opened and then closed again at the completion of some downhole operation. As the shifting tool enters the closed port collar, the opening portion 410 passes through the formations opposite the locking system 301 and subsequently, the opening portion 410 interacts with formations opposite the locking system 300 and the shifting tool becomes fixed within the sleeve 206 . In this position, the shifting tool urges the buttons 335 of the locking system 300 outwards thereby moving the C-rings 370 out of engagement with the ratchet teeth 325 of the sleeve. Continued force applied to the shifting tool 400 will then urge the sleeve 206 down and into the open position. Thereafter, continued force upon the shifting tool 400 causes the collet-like fingers of the opening portion 410 of the shifting tool to collapse and come out of engagement with cavities of the sleeve 206 , as illustrated in FIG. 5 A. The present invention can also be used in a wellbore wherein numerous port collars 200 are arranged in series at various depths in the well and are then alternately opened or closed by multiple shifting tools run into the well along a run-in string. FIG. 6 is a side view of a wellbore showing a plurality of port collars 200 disposed on a string of tubulars 220 . For example, port collars 200 can be located adjacent formations and then selectively opened to access production fluid. Subsequently, the port collars 200 can be re-closed isolating the interior thereof from the annular well fluid. In other examples, the port collars 200 are opened to permit cement to be injected into the annular area therearound and then re-closed after the cementing process is complete. As a run-in string with shifting tools installed therein is lowered into a wellbore, the opening tool portion 410 of the shifting tool opens the port collars as it passes therethrough. Closing portion 450 of the shifting tool, because it is designed to operate only while moving in an upward direction through the port collars 200 , passes downward through the port collars 200 with no effect. After the shifting tool 400 has passed through and opened all of the port collars 200 , the run-in string housing the shifting tools can be pulled upwards towards the surface of the well such that the closing portion of a shifting tool 450 will re-close the lower most port collars. Finally, if necessary, the opening portion 410 of the shifting tool 400 can then be lowered back through an intermediate port collar(s), leaving the port collar(s) in the open position. In this manner, port collars are selectively opened and closed in a string of multiple port collars. While foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. In the open position, the port collar permits communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking mechanism for the opened and closed positions comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. The mating ratchet teeth are designed to secure the sleeve in a first position within the housing. A second set of mating ratchet teeth secures the sleeve in a second position.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to connecting external devices and systems to a computer, and more particularly, to connecting external devices and systems having different functions to a computer using a shared port/connector. 2. Description of the Related Art The usefulness of a computer can be increased through devices and systems that can be connected to the computer. To accommodate such interconnection, computers commonly are equipped with various ports through which external devices can be connected to the computer. These external devices and systems may include, among others, printers, modems, local area networks (LANs), external drives, keyboards, and pointing devices. In turn, internal boards of the computer include wiring connected to each port that gives the computer the capability to utilize the external device which is connected to that port. FIG. 1 depicts a conventional computer system 100 configured to connect with two different external devices or systems to thereby operate two different functions. Two functions which are greatly needed in the majority of today's computers are ethernet and modem capability. The ethernet function is required for networking with other computers, and the modem function is required, for example, for sending facsimiles from the computer and for connecting the computer system to the Internet. Because of the widespread use of these functions in today's households and workplaces, inclusion of these features are often essential to the marketability of the computer system. FIG. 1 more specifically depicts a computer system 100 that accommodates interconnection with a 10baseT ethernet system and a telephone system. A signal from an ethernet system (not shown) is carried via an ethernet line 110 terminating in an ethernet 8-pin modular plug 108. Although the ethernet 8-pin modular plug 108 has eight ethernet plug pins 118, only four, typically pins numbered as 1, 2, 3, and 6 in FIG. 1, are connected to the ethernet line 110. To accommodate connection with the ethernet system, the computer system 100 includes an ethernet circuit 102. The ethernet circuit 102 is connected to an ethernet 8-pin modular jack 106 which provides a port on the edge of the computer system 100. To connect the computer system 100 to the ethernet line 110, the ethernet 8-pin modular plug 108 is inserted into and engaged with the ethernet 8-pin modular jack 106. Therefore, only four of the ethernet modular jack pins 120, those corresponding to the pins used on the ethernet 8-pin modular plug 108, are used on the ethernet 8-pin modular jack 106. A signal from a telephone system (not shown) is carried via a telephone line 116 terminating in a 4-pin telephone plug 114. As with the ethernet 8-pin modular plug 108, not all of the telephone plug pins 122 on the telephone 4-pin modular plug 114 are used. Rather, the telephone line 116 typically uses only pins 2 and 3. To accommodate connection with the telephone system, the computer system 100 also includes a modem circuit 104. The modem circuit 104 is connected to a telephone 4-pin modular jack 112 which provides another port on the edge of the computer system 100, thus further decreasing the space available for other such ports. To connect the computer system 100 to the telephone line 116, the telephone 4-pin modular plug 114 is inserted into and engaged with the telephone 4-pin modular jack 112. Therefore, the modem circuit 104 is connected to those telephone modular jack pins 122 which correspond to the two pins used on the telephone 4-pin modular jack 112. As shown in FIG. 1, typical configurations of computer systems may include both ethernet and modem capability which requires the use of two ports. Other ports are also needed for other external device or system functions desired. Each port required increases the amount of surface area required, and correspondingly decreases the amount of surface area available for other ports. Typically, desktop computer systems have a fairly large surface area that can be used for such ports, and therefore the designer is free to include many ports, and therefore functions, in desktop computer systems. However, due to convenience and cosmetic reasons, computers are built such that they normally only use the back side of their housing for ports. Hence, there is a limited surface area available for ports. In the case of portable computers, the limited surface area is more restrictive because portable computers must be limited in overall size and must be easily carried to be useful. With such limited space available for ports, the computer designers are forced to limit the number of external devices that can be connected to the computer, and thus limit the functionality of the computer. The designer is forced to make difficult choices not to include some functions, thus making the computer system less marketable. Also, the consuming public demands continued reduction in the size of computers, in particular portable computers. Such continued reduction of overall size results in even further reduction in the surface area available for ports and in the number of functions available with the computer. Thus, there is a need for better utilization of the limited surface area available for ports on computers. SUMMARY OF THE INVENTION Generally, the present invention is a multiple function peripheral connecting device that allows more functionality in the limited area for ports on a computer. More specifically, the present invention provides the capability for external devices having different functions to be connected to the computer through a single port. This is accomplished by wiring a first function, internal to the computer, to certain pins of a modular connector, and wiring a second function, also internal to the computer, to other pins on the same modular connector. The present invention is particularly well suited for use with a portable computer. One embodiment of the present invention provides external connection through one port for both ethernet and modem functions. To accomplish this, the ethernet function within the computer is wired to certain pins on an 8-pin modular jack, and the modem function within the computer is wired to different pins on the same 8-pin modular jack. Because both an 8-pin modular plug used by an ethernet system, and a 4-pin modular plug used in phone systems both fit into an 8-pin modular jack, less space is used by the present invention than if separate jacks were used for the two functions. Furthermore, when the 8-pin modular plug is inserted into the 8-pin modular jack, the ethernet function is automatically activated, and when the 4-pin modular plug is inserted into the 8-pin modular jack, the modem function is automatically activated, without use of additional hardware. In a second embodiment of the present invention an adapter couples with the computer system of the first embodiment, allowing simultaneous use of the two functions which are connected to different pins of the 8-pin modular jack. These and other features and advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: FIG. 1 is a diagram illustrating a conventional computer system. FIG. 2 is a diagram illustrating a computer system incorporating a first embodiment of the present invention. FIG. 3a is a diagram illustrating an ethernet system plug aligned with the computer system shown in FIG. 2. FIG. 3b is a diagram illustrating the connection of the ethernet plug and computer system shown in FIG. 3a. FIG. 4a is a diagram illustrating a telephone system plug aligned with the computer system shown in FIG. 2. FIG. 4b is a diagram illustrating the connection of the telephone plug and computer system shown in FIG. 4a. FIG. 5 is a diagram illustrating an adapter, according to a second embodiment of the present invention, used with the computer system shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the invention are discussed below with reference to FIGS. 2-5. Telecommunications equipment has benefited from the design of electrical plugs and receptacles (jacks) that provide easy connect/disconnect capability between electrical circuits within the telecommunications equipment. Such plugs and jacks, commonly referred to as modular plugs and jacks, are particularly popular in association with telephone sets where they were first used. Modular plugs and jacks have been so well received that their specifications are standardized, and can be found in Subpart F of the FCC-Part 68.500 Registration Rules. Modular jacks provide a convenient means for connecting and disconnecting telephone equipment, telecommunications equipment, and computer-related equipment. Common modular jacks conventionally comprise between two and eight contacts, or pins, embedded within a generally rectangular plastic housing having a cavity capable of receiving a modular plug. The modular jacks may also have more than eight contacts or pins. Portions of each contact are exposed within the cavity, thus allowing electrical connection to corresponding contacts on a modular plug. In addition, attachment portions of each contact extend beyond the housing, allowing electrical connection between the jack contacts and a printed circuit board or the like. Thus, connecting a plug and jack, both having corresponding contacts connected to their respective devices or systems, allows electrical connection between the two devices or systems. The design standardization of common modular jacks allows equipment utilizing such jacks to be interchangeably connected to a single plug. For example, using such designs for telephone plugs and jacks allows phone units to be moved from room to room or from house to house without requiring modification of the corresponding receptacles. Another benefit of such design standardization is that it enables jacks to receive any plug having fewer pins than the jack includes. Thus, an 8-pin jack could alternately receive either an 8-pin plug or a 4-pin plug. FIG. 2 is a diagram illustrating a computer system 200 incorporating a first embodiment of the present invention. Computer system 200 includes an ethernet circuit 202, a modem circuit 204, and an 8-pin modular jack 206 with pins 1, 2, 3, and 6 of the pins 220 coupled to the ethernet circuit 202, and with pins 4 and 5 of the pins 220 coupled to the modem circuit 204. FIG. 3a illustrates how the computer system 200 according to the first embodiment of the present invention accommodates interconnection with an external ethernet system (not shown). Two commonly used ethernet systems are 10baseT and 100baseTX each of which typically use four lines, two for transmit and two for receive, and an 8-pin modular plug. Therefore, for 10baseT or 100baseTX four of the pins 118 of an ethernet 8-pin modular plug 108 are used, typically those numbered 1, 2, 3 and 6 with two pins being transmit pins and two being receive pins. Because of the standard construction of the 8-pin modular jack 206, it can receive the ethernet 8-pin modular plug 108. Two of the pins 220 (selected from the pins numbered 1, 2, 3 and 6) of the 8-pin modular jack 206, that correspond to the transmit pins of the ethernet 8-pin modular plug 108 are electrically connected to that portion of the ethernet circuit 202 performing transmit functions, while the two other of the pins 220 that correspond to the receive pins of the ethernet 8-pin modular plug 108 are electrically connected to that portion of the ethernet circuit 202 performing receive functions. Thus, because the ethernet circuit 202 and the ethernet system are connected to the same pins on the 8-pin modular jack 206 and the ethernet 8-pin modular plug 108, respectively, when the ethernet 8-pin modular plug 108 is inserted into the 8-pin modular jack 206, as shown in FIG. 3b, the ethernet circuit 202 is coupled with the external ethernet system carried via the ethernet line 110. Thereafter, the ethernet function is able to operate in a manner similar to that in a conventional computer system. FIG. 4a is diagram illustrating how the computer system 200 according to the first embodiment of the present invention accommodates interconnection with an external telephone system (not shown). A typical telephone system uses two lines, commonly referred to as "tip" and "ring", and a 4-pin modular plug. Therefore, for such a telephone system, only two of the set of pins 122 of a telephone 4-pin modular plug 114 are used, typically the center pins numbered 2 and 3 with one pin being connected to the "tip" line and the other with the "ring" line. In the first embodiment of the present invention, instead of including a second modular jack on the computer system 200 to provide a port through which the telephone line and modem circuit can connect, such as the modem 4-pin modular jack 112 does in the conventional computer system 100 shown in FIG. 1, the modem circuit 204 is connected to the 8-pin modular jack 206. More specifically, the modem circuit 204 is connected to the two center pins of the 8-pin modular jack pins 220. Although the telephone 4-pin modular plug 114 and the 8-pin modular jack 206 are of different sizes, the standard construction of an 8-pin modular jack and a 4-pin modular plug are such that it allows a 4-pin. modular plug to be inserted to the center of an 8-pin modular jack. Therefore, when the telephone 4-pin modular plug 114 is inserted to the 8-pin modular jack 206 of the present invention, as shown in FIG. 4b, the external telephone system is coupled to modem circuit 204. Thus, by using standard parts, this embodiment of the present invention maintains the same level of peripheral functionality while reducing the number of parts used. Also, this is accomplished while reducing the amount of surface area of the computer required to support the peripheral functionality, thereby leaving more surface area available for the incorporation of other functions and their corresponding ports. Therefore, the options of the designer are expanded, and a more marketable computer is developed at lower cost. FIG. 5 illustrates a second embodiment of the present invention, in which an adapter 500 couples to the computer system 200 described above to provide additional peripheral functionality. Adapter 500 includes an 8-pin modular plug 502, an 8-pin modular jack 504, and a 4-pin modular jack 506. Pins 1, 2, 3, and 6 of pins 508 on the 8-pin modular plug 502 are electrically coupled with pins 1, 2, 3 and 6 of pins 510 on the 8-pin modular jack 504. Further, pins 4 and 5 of pins 508 are coupled with pins 2 and 3 of pins 512 on 4-pin modular jack 506. Thus, when the 8-pin modular plug 502 is connected to the 8-pin modular jack 206, the ethernet circuit 202 is electrically connected to pins 1, 2, 3 and 6 of the 8-pin modular jack 504, and the modem circuit 204 is electrically connected to the center pins of the 4-pin modular jack 506. Therefore, by using the adapter 500, both an ethernet system using pins 1, 2, 3 and 6 of an 8-pin plug and a telephone system using the two center pins of a 4-pin plug can be connected to the computer system 200 and utilized simultaneously. Thus, the second embodiment of the present invention provides, at a low cost, a computer having the ability to simultaneously interact with both ethernet and telephone systems, while also having available surface area for other ports. In the embodiments described above, the two systems that utilize the same 8-pin modular jack on the computer system of the present invention are an ethernet system (e.g., 10baseT or 100baseTX) and a modem system. However, the present invention provides connection for other combinations of peripheral functions as well. For example, a computer system including a modem circuit and an ATM Forum Standard circuit will operate according to the present invention through electrical connection to pins 4 and 5, and pins 1, 2, 7 and 8, respectively, of an 8-pin modular jack located at a peripheral portion of the computer system. In conjunction with such connection, a standard telephone system using a 4-pin modular jack and an ATM Forum Standard system using an 8-pin modular jack can alternately connect to the same 8-pin modular jack of the computer system. Likewise, a computer system including a Token Ring LAN circuit and an ATM Forum Standard circuit will also operate according to the present invention when coupled to pins 3, 4, 5 and 6, and to pins 1, 2, 7 and 8, respectively, of an 8-pin modular jack located on a peripheral portion of the computer system. In conjunction with such connection, a Token Ring system using an 8-pin modular jack and an ATM Forum Standard system using an 8-pin modular jack can be alternately connected to the same 8-pin modular jack of the computer system. It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.

A multiple function peripheral connecting device that allows more functionality in the limited port space of a computer is disclosed. The connecting device provides the capability for external devices having different functions to be connected to the computer through a single port. This is accomplished by wiring a first function, internal to the computer, to certain pins of a modular connector, and wiring a second function, also internal to the computer, to a certain different combination of pins on the same modular connector. Because differently sized plugs can fit with the modular connector, peripherals associated with different types of systems can connect with the computer through the same single jack. Also, an adapter may be connected to the computer to allow simultaneous use of the two internal functions.

FIELD OF THE INVENTION The present invention includes subject matter drawn to a system and method for analyzing the delivery of business systems management services. BACKGROUND OF THE INVENTION Today's distributed processing business systems often include resources from multiple vendors and platforms connected through large open networks. To understand the status of a particular resource in a modern business system is to comprehend only a small part of the picture. To truly maximize the business value of business system investments, a business also must see how each resource affects the applications and business processes it supports. Many resources in a distributed processing system are interdependent, and businesses must be able to demonstrate and leverage linkages between business systems and business processes. These links are critical to being agile, allowing business processes to drive technology decisions and priorities. Without these links, a business has virtually no way of knowing how an individual resource, or group of resources impact a given business process. If, for example, a particular Web server were to go down, a business would not be able to identify specific business processes that would be adversely affected. Business systems management (BSM), also sometimes referred to as “business service management,” is an evolving technology that can be employed to help a business understand how the performance and availability of technology resources affect the applications, processes, and services that power a business. BSM technologies help a business prioritize technology resources that carry the highest business values, not just the latest problem that crops up. Revenue-generating activities, such as order processing—rather than internal processes, such as a human resources system—are prioritized in the event of a problem or outage. BSM software products, such as TIVOLI Business Systems Manager from International Business Machines Corporation, enable a business to align daily operations management with business priorities, set and meet service level commitments, implement predictive management capabilities across business systems infrastructure, and generate reports to keep executives and business units that use the business's services informed and productive. Problem management techniques, though, have not kept pace with the rest of BSM technology. Unlike the modern business systems just described, early business systems were based upon a relatively simple mainframe design that generally comprised a single mainframe computer connected to user terminals through a closed network. Problems in these early business systems could be detected simply by monitoring the network and the mainframe computer for undesired or unexpected performance. Likewise, any such problems could be resolved by repairing or adjusting one of these two components. Clearly, such limited problem management techniques are inadequate for analyzing problems in a modern, complex business system in which the links between business systems and business processes are so critical. To effectively resolve problems in a modern business system, a business first must be able to identify the source of the problem—which itself may be a daunting task. The source of the problem could be a technology resource, a business process, a link between a resource and a process, or any combination thereof. Problem identification, though, is not the only new hurdle for modern business systems management. A single change to a single component of a business system can have widespread effects on many interdependent components. Sometimes, such changes can produce unexpected and undesired results. Thus, once a problem has been identified, a business also must be able to evaluate possible solutions to determine the effect of the solution on the business system as a whole. Accordingly, there currently is a need for a problem management system that can identify a problem in a modem business system and evaluate the effect of a solution on the business system as a whole. SUMMARY OF THE INVENTION The invention described in detail below is a method for analyzing a problem in a distributed processing business system used to provide a service. The method comprises identifying the problem; preparing for an audit; performing the audit; reviewing the audit; developing an action plan; developing an execution plan; deploying a solution in accordance with the execution plan; monitoring the deployed solution; and recording lessons learned. Alternatively, the method may be applied to evaluate the capacity of a distributed processing business system to provide a prospective service. In this alternative embodiment, the method comprises identifying the problem; preparing for an audit; performing the audit; reviewing the audit; preparing a rating table; populating the rating table with results from the audit; calculating a service rating based upon the results entered in the rating table; and presenting the service rating to management. If approved, the service provider develops an action plan; develops an execution plan; deploys a solution in accordance with the execution plan; monitors the deployed solution; and records lessons learned. BRIEF DESCRIPTION OF DRAWINGS The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be understood best by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: FIG. 1 illustrates the relationship between a process and a service; FIGS. 2A-2B provides an overview of the problem analysis methodology; FIG. 3 is a flowchart of the Problem Identification sub-process; FIGS. 4A-4F is an exemplary worksheet used in the Problem Identification sub-process for identifying problems in the project office data; FIGS. 5A-5E is an exemplary worksheet used in the Problem Identification sub-process for identifying problems with a process or processes; FIGS. 6A-6E is an exemplary worksheet used in the Problem Identification sub-process for identifying problems with a procedure or procedures; FIG. 7 is an exemplary interface/intersection validation form; FIGS. 8A-8B is a flowchart of the Prepare for Audit sub-process; FIG. 9 is a flowchart of the Perform Audit sub-process; FIG. 10 is a flowchart of the Review & Record sub-process; FIG. 11 is a flowchart of the Action Plan Development sub-process; FIGS. 12A-12F is an exemplary exit criteria worksheet; FIG. 13 is a flowchart of the Execution Plan Development sub-process; FIG. 14 is a flowchart of the Deploy Solution sub-process; FIGS. 15A-15B is a flowchart of the Reevaluate sub-process; FIGS. 16A-16B is a flowchart of the Monitor Deployment sub-process; FIG. 17 is a flowchart of the Prospective Account Evaluation process; and FIG. 18 is an exemplary rating table. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The inventive analysis methodology described in detail below generally is applied to business systems that are used to deliver a service to a consumer. In this context, a “consumer” may be internal or external to the service provider, and a “service” represents any function having tangible or intangible value to the consumer. The methodology comprises techniques for evaluating, researching, and analyzing processes and technology associated with a service. More particularly, the methodology provides a means to evaluate, research, and analyze “problems” with processes and technologies associated with a service. Moreover, the methodology may be applied to a service as a whole, to any distinct process used to deliver a service, and may be applied throughout the timeline of a service. The service may be an existing service or a prospective service. Of course, the term “problem” has many definitions and implications associated with it, which depend on context. For example, poor financial performance or failing to meet contract and customer expectations are conditions that may indicate a problem with the underlying processes or technology. Sometimes, though, the methodology may be invoked even in the absence of any specific problem indicators, such as when a customer or provider believes there is room for improvement. Before describing this methodology in detail, it is important to clarify some nomenclature. In particular, is important to distinguish services from processes and procedures. FIG. 1 is a diagram that illustrates the relationship between a service and processes. “Processes” are internal activities that a business uses to deliver a service. As FIG. 1 indicates, the same process or processes may be used to provide a variety of services. “Technology” refers to the tools that are exploited in the course of executing those processes. Technology includes computer hardware and software. “Procedures” are activities that employ the tools to animate the processes that deliver the service. It also is important to identify the various roles of participants in the activities required to deliver a service. There are four distinct roles within this methodology, although the same individual might fill several roles. A brief overview of these roles is provided here, but more specific responsibilities will be identified as the details of the inventive methodology are described below. First, the “project office” or “account office” is responsible for ensuring that service is delivered according to contractual obligations, and for monitoring the financial performance of the service delivery. Second, a “service delivery manager” or “account manager” is responsible for delivering all services for a specific account according to contractually defined service-level agreements. Third, an “auditor” is responsible for the auditing activities described below. The auditor also is responsible for coordinating all activities, developing the scope of an audit, and completing worksheets. Fourth, the “delivery team” is responsible for executing procedures and processes that support service delivery for a specific account in accordance with contractual service-level agreements. Members of the delivery team also participate in developing the scope of an audit, provide input to the audit, and analyze the results of the audit. FIG. 2 provides an overview of the inventive methodology applied to an existing service. The methodology is referred to hereinafter as the “problem analysis” methodology. As FIG. 2 illustrates, the problem analysis methodology ( 200 ) may be initiated ( 202 ) as a periodic event or the result of a request from a customer, the project office, the service delivery manager, or the delivery team ( 204 ). Once initiated, the auditor identifies the problem and determines the scope of the audit ( 300 ). The auditor then prepares for the audit ( 800 ), performs the audit ( 900 ), reviews the results of the audit, ( 1000 ) and then presents the results to management. Management determines whether to continue ( 214 ). If management determines to continue, the auditor develops an action plan for updating the processes or technology ( 1100 ). The auditor next prepares a plan of execution consistent with the action plan ( 1300 ). The delivery team then deploys the solution in accordance with the plan of execution ( 1400 ). As the delivery team deploys the solution, errors or unknown events may impact the success of the deployment ( 222 ). If the deployment is unsuccessful, the Reevaluation sub-process is invoked to address these issues ( 1500 ). If the deployment is successful, it is monitored in the production environment to ensure that it functions and performs as expected ( 1600 ). If unexpected errors are revealed during this monitoring process, the Reevaluation sub-process may be invoked to correct these errors ( 228 ). Each of these activities is described in more detail below. FIG. 3 illustrates the Problem Identification sub-process ( 300 ). The Problem Identification sub-process focuses on project office data (which may include service delivery data), processes and procedures, and technology. Upon receiving a request for an audit ( 302 ), the auditor reviews the processes and services that are the subject of the request ( 304 ). To guide the analysis, an auditor completes a worksheet for the project office data, processes and procedures, and technology ( 306 ). Exemplary worksheets are provided in FIGS. 4 , 5 , and 6 . The auditor may request support from associated services to ensure that the best information is included. The auditor then determines the core process or service, and associated called and answering services ( 308 ). The selected core process or service generally works with other processes to perform a service. As such, the core service must consider the associated services that contribute to either the success or the failure of the service. The auditor reviews the service from end-to-end, and completes the interface/intersection validation form. An exemplary embodiment of this form, which considers the calls and answers as well as the technology that enables it, is illustrated in FIG. 7 . The auditor then contacts other process or service owners and advises them of the audit and provides data from the worksheets and validation form ( 312 ). The delivery teams then review their schedules and reserve time for the audit. Next, the team reviews the information provided by the auditor and if necessary offers changes or suggestions to the forms ( 314 ). This effort is intended to make the data as complete and robust as possible prior to the audit. If the delivery team offers changes or suggestions ( 316 ), the auditor updates the problem identification forms to reflect these changes or suggestions ( 306 ). The auditor next provides the forms to technologists and advises them of the impending audit ( 318 ). The technologists also review the forms and determine if they can add any information or contribute any change data ( 320 ). If necessary ( 322 ), the auditor then updates the problem identification forms again ( 306 ). FIG. 8 illustrates the Prepare for Audit sub-process ( 800 ). To prepare for an audit ( 802 ), an auditor first collects all problem identification worksheets completed during earlier steps ( 804 ). The auditor also collects other relevant information, such as process documents, procedures, instructions, policies, measurements, service level agreements, contract details, etc. The auditor then reviews all documents and information ( 806 - 808 ) to ensure that they include consistent data, such as version numbers, the number of pages, workflows, etc. If the data is inconsistent ( 810 ), the auditor reviews the documents with the delivery teams ( 811 ). The auditor and the delivery teams must then agree which version of the documents or data best addresses the elements of the service ( 813 ). If the data is consistent ( 810 ) or has been agreed upon ( 813 ), the auditor makes paper copies of all documents ( 812 , 815 ), completes the interface forms, and makes copies for team review ( 814 ). The auditor then prepares an audit plan and an audit questionnaire ( 816 ). The auditor next sends audit notices to appropriate teams ( 818 ). The teams then identify relevant resources and allocate time for the audit. Next, the auditor sends all finalized reference documents to the team members that have been identified to support the audit ( 819 ). Each team then reviews the documents as a final check before moving forward ( 820 ). This permits opportunity for changes if required ( 822 ). The auditor collects all inputs from the teams and reviews them. This review either confirms the data as it is or modifies the data. In the event that data has been modified, the auditor must discuss the modifications to ensure an accurate understanding or determine if the modification is required. If modifications are required, the auditor formally updates the data based on the modifications suggested by the team and the validation of the modifications, and makes copies and distributes copies to the team ( 824 ). The auditor then selects the element or elements for the audit ( 826 ). The suggested element should be a feature that best exercises as many, if not all, of the features offered in the service to be examined. Several elements may be selected to ensure that all aspects of the service are exercised. The auditor then prepares for a review with management ( 828 ), which is intended to inform and gain their concurrence. Management then reviews the audit plan and determines whether to proceed with the audit as planned ( 830 ). If management does not concur with the audit plan, the auditor restarts the Prepare for Audit sub-process ( 832 ). Otherwise, the auditor sends a second audit notice to the teams ( 834 ). FIG. 9 illustrates the Perform Audit sub-process ( 900 ) in detail. The auditor begins the sub-process by verifying that all team members have the most up-to-date documents to be used in the audit ( 902 ). The auditor also ensures that all team members know the objectives and the elements to be used to track and monitor the audit ( 904 ). The auditor provides missing information, if necessary ( 906 ), and then proceeds with the audit walk-through. In the audit walk-through, the service is called and the operational process begins ( 910 ). As the operational process continues, the auditor uses problem identification forms 400 - 600 , interface/intersection form 700 , and the audit questionnaire 916 to evaluate each step of the operational process. The auditor also should note technology intersections. Once all audit walk-throughs are complete, the auditor conducts a cursory review of data to ensure that all issues have been commented on ( 918 ). After concluding the cursory review, the auditor and the team determine if the examination is complete and the data is sufficient to move forward ( 920 ). If the auditor and the team determine that the examination is incomplete, the auditor restarts the Perform Audit sub-process ( 922 ). Otherwise, the auditor informs the team that the audit is complete ( 924 ). FIG. 10 illustrates the sub-process for reviewing audit results, preparing findings, and presenting findings ( 1000 ). The objective of this sub-process is to organize the audit results and findings into a meaningful format that will support the development of an action plan. First, the auditor and the team review all of the data generated ( 1004 ). This data includes problem identification forms 400 - 600 , interface/intersection validation form 700 , and all other documents 1010 used to review the audit. This information includes, but is not limited to, process charts, procedures, policy documents, etc. The information is formatted so that it provides clear indicators of successful and unsuccessful points of execution. The team then must determine if corrective action can improve the service ( 1012 ). If the team determines that corrective action is proper, the team must gain concurrence from the auditor and a commitment to take the corrective action ( 1014 ). The team then documents the results and findings, and makes a recommendation ( 1016 ). If the results and findings do not suggest a good plan of action or provide a timeframe for development and implementation, the documentation must reflect this ( 1018 ). The auditor prepares an estimate of the time and manpower that will be required to take the corrective action ( 1020 ). The estimate should consider, at a minimum, the manpower and time for planning and development, implementation, and monitoring. The auditor and team next present the findings to management ( 1022 ). This step assists in the validation of the effort and also gains management support for the next steps. If management disagrees with the findings, the auditor may restart this sub-process ( 1024 ), or management may instruct the team to update the documentation ( 1026 ) to ensure that all are consistent and end the effort ( 1028 ). FIG. 11 illustrates the Action Plan Development sub-process ( 1100 ). In this sub-process, the team first gathers all data collected during the audit and uses this data to examine each of the components of the service. The team identifies all discrepancies as they relate to the process, procedures, and tools ( 1102 ). Next, the team reviews each issue individually or as a logical grouping, and determines what action is required ( 1104 ). The team then modifies the process, procedures, tools, and information as required. Changes to the tools should be performed in such a manner that normal production is not affected ( 1106 ). The team next begins an end-to-end walk-through of the service to test the corrective action. If additional issues need to be reviewed ( 1108 ), this sub-process may be repeated as indicated in FIG. 11 . The team then establishes exit criteria and selects a model for demonstrating that the service has been corrected ( 1110 ). An exemplary exit criteria worksheet is provided in FIG. 12 . Finally, the team must agree if monitoring is required and, if so, the length of time that monitoring is to occur ( 1112 ). FIG. 13 illustrates the Execution Plan Development sub-process ( 1300 ). This sub-process updates the necessary documents, organizes all of the components, and sets in place the plan for deploying the solution. The team first develops a Communication Plan ( 1302 ). To develop a communication plan, the team reviews all entities that will be impacted by the release of the solution. From this information, the team creates the appropriate dialogue, which discusses the solution, what it includes, benefits, and when it will be released. The team then makes the final modifications and updates to the documents ( 1304 ). This includes policy notations on the process flows and validation of the call and answers requirements in the flow, as well as the technology intersections and validation of the interface. Measurements are noted and the means for creating management reports are in place. Considerations for escalation requirements and procedures also are updated and modified. Exit criteria are then reviewed and confirmed ( 1306 ). With the Action Plan and the Execution Plan in place, the team then deploys the corrective action in the production environment ( 1400 ). This sub-process is illustrated in FIG. 14 . The team first releases the Communication Plan to all parties ( 1402 ). The auditor then contacts all parties to ensure that the solution is ready to be deployed ( 1404 ). Each team member then deploys the solution according to the Execution Plan ( 1406 ). The auditor ensures that the process documents are in place, contacts the technology group and ensures that the tools are in place and ready for use, and checks with the delivery team to ensure that the procedures are in place and ready for use. If “work-arounds” are implemented during the deployment process, these items should be backed out and kept ready in case the solution fails ( 1408 ). The team then revalidates the work to ensure that all components are in place ( 1410 ). This is the last check after the work-arounds have been removed. The solution should now be in place, and test scenarios should be exercised to ensure that the solution is functional in production ( 1412 ). The test results should reflect the success of the deployment and of the solution ( 1413 ). If one or more of the tests fail, the team should determine if a quick fix can be implemented, or if the solution must be re-evaluated. If a quick fix is feasible, the team implements the quick fix and runs the test scenarios again ( 1414 ). If there is no feasible quick fix, the team backs out the release ( 1416 ), notifies the appropriate parties ( 1418 ), and re-evaluates the effort (see Reevaluate sub-process 1500 , below). If the tests are successful, the system is ready for customer use. The Reevaluate sub-process ( 1500 ), illustrated in FIG. 15 , allows the team to review work and present findings to the appropriate management if the solution fails to perform properly in the production environment. Based on the release, the team organizes the items that failed or items, data, or elements that caused the deployment to fail ( 1502 ). The team then reviews each item in detail and defines the work required to update or correct the issues ( 1504 ). The auditor next gathers all of the information, records the information, and suggests a new plan of action based upon the team input ( 1506 ). The team then prepares time and manpower estimates based upon the new plan of action ( 1508 ). The auditor then organizes and formalizes the new Action Plan ( 1510 ) and estimates, reviews the information with the team ( 1512 - 1516 ), and presents the information to management to gain concurrence or determine if additional information is required ( 1520 ). If management requests additional information, the team again reviews the issues and defines the work required to update or correct the issues ( 1504 ). Management then decides whether or not to move forward with the effort ( 1522 ), and optionally, may provide special instructions ( 1524 ). If management provides additional instructions, the auditor gathers any information relevant to the instructions and distributes the information to the team ( 1526 ). If management decides not to proceed, the team ensures that the service is performing as it was performing prior to the work, and the team is released from any further responsibilities ( 1528 ). After the solution is deployed, the service provider monitors the operational process to ensure that it is performing as expected ( 1602 ), as illustrated in FIG. 16 . If monitoring reveals unexpected performance or other issue ( 1604 ), the team examines the conditions and determines if a quick fix can be made to correct the issue ( 1606 ). If the team has determined that a quick fix is feasible, the team implements the quick fix and updates all documentation to reflect the changes necessitated by the quick fix ( 1608 ). The team then determines if the quick fix is working as intended. If the quick fix is working as intended, the team continues the monitoring process until all exit criteria have been satisfied ( 1610 ). If the quick fix is not working as intended, the team must reverse the corrective action and restore the original service ( 1612 ). The auditor notifies the appropriate parties ( 1614 ) that an issue caused the corrective action to fail, and the team begins to re-evaluate the problem ( 1500 ), as described above with reference to FIG. 15 . When the team determines that the corrective action satisfies all exit criteria ( 1618 ) established in the Action Plan, the team completes the exit criteria worksheets and records lessons learned ( 1620 ). The auditor then updates all dates, version numbers, etc. in all documents ( 1622 ), notifies the appropriate parties that work is complete ( 1624 ), and releases the team from the effort ( 1626 ). As noted above, the inventive methodology also encompasses the evaluation of prospective services. FIG. 17 illustrates the application of the methodology to such a prospective service. This application of the methodology is referred to here as the “prospective account evaluation” methodology ( 1700 ). The object of the prospective account evaluation methodology is to provide assurance to the service provider that a service can be delivered in such a manner that it meets or exceeds customer expectations while producing a profit. In the context of prospective account evaluation methodology ( 1700 ), the term “customer” refers to the prospective end-user of the service or services that the service provider is offering. A “service requester” is a liaison between the customer and the service provider. The service requester accepts requests from the customer and coordinates the prospective account evaluation with the service provider. The prospective account evaluation begins when the service requester receives a request to evaluate a new account or a single service ( 1702 ). The service requester gathers relevant information and formats it as required for the service provider to review. This information should describe all elements of the service and the desired output. Other information also may describe the customer's current technology, key contacts within the customer's organization, desired schedules, etc. The service provider then receives the request and reviews the information to ensure that the data is adequate to support the evaluation. The service provider also may request the service requester to provide additional information before continuing. The service provider then prepares an audit questionnaire ( 1704 ). The service provider then proceeds with steps 300 , 800 , & 900 , described above. The output of this step provides insight into other requirements, the projected time to perform, tools, and interactions with other services. The service provider may have an existing tool for modeling a service or set of services ( 1706 ). If the service provider does not have such a tool, then the service provider should prepare a rating table ( 1708 ). An exemplary rating table is provided in FIG. 18 . This rating table is a template and should be modified to meet the needs of the prospective account. The service provider then populates the rating table with data from the audit ( 1710 ) and reviews the rating with appropriate management ( 1712 ). As used in the exemplary rating table, a service rating of “low risk” indicates that the service requires a simple design with minimal impact to existing technology infrastructure, and that appropriate levels of customer satisfaction could be achieved with an adequate profit margin. A “medium risk” rating suggests that the service is within the known customer cost and satisfaction tolerance of the service provider, and that the service should produce a profit, but with greater impact on existing infrastructure. A “high risk” rating suggests that the prospective account may not be in the best interests of the customer or the service provider. Ultimately, management is responsible for considering the service rating in light of all other factors and for deciding to enter into a contractual relationship for the delivery of the prospective service. If management decides to enter into such a relationship, many aspects of problem analysis methodology ( 200 ) described above may be applied develop operational processes that support delivery of the prospective service. In particular, the service provider may develop an action plan ( 1100 ), develop a plan of execution ( 1300 ), deploy the processes or service in accordance with the plan of execution ( 1400 ), monitor the deployed processes or services ( 1600 ), and record lessons learned ( 1620 ). A preferred form of the invention has been shown in the drawings and described above, but variations in the preferred form will be apparent to those skilled in the art. The preceding description is for illustration purposes only, and the invention should not be construed as limited to the specific form shown and described. The scope of the invention should be limited only by the language of the following claims.

A method for analyzing a problem in a distributed processing business system used to provide a service is disclosed. The method comprises identifying the problem; preparing for an audit; performing the audit; reviewing the audit; developing an action plan; developing an execution plan; deploying a solution in accordance with the execution plan; monitoring the deployed solution; and recording lessons learned. Alternatively, the method may be applied to evaluate the capacity of a distributed processing business system to provide a prospective service. In this alternative embodiment, the method comprises identifying the problem; preparing for an audit; performing the audit; reviewing the audit; preparing a rating table; populating the rating table with results from the audit; calculating a service rating based upon the results entered in the rating table; and presenting the service rating to management.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. application Ser. No. 10/811,815 filed Mar. 30, 2004, the entirety of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention relates to a method and apparatus to perforate or re-perforate a well and then to substantially and immediately thereafter circulate a fluid for removal of solids and debris from an underground formation for an aggressive completion or stimulation. BACKGROUND OF THE INVENTION [0003] To recover hydrocarbons such as oil and natural gas from subterranean formations through a wellbore penetrating the earth to the hydrocarbon-bearing formation, it is common to perform a completion, including perforating, and in some circumstances to perform some type of stimulation procedure in order to enhance the recovery of the valuable hydrocarbons. [0004] In order to recover the hydrocarbons, a well is drilled from the surface to the formation. Following drilling, the well is generally completed by installing a tubular well casing in the open borehole and cementing the casing in place. Because the casing and cement forms a continuous hollow column, no wellbore fluids are able to enter the well, to be transported to, and to be recovered at the surface. [0005] For this reason, it is common to provide openings through the casing and cement annulus in the zone of interest; by perforating the casing and cement into the surrounding formation to provide access from the formation into the wellbore for recovery of the formation fluids. In situations where existing perforations are deemed inadequate the formation can be stimulated using a variety of other techniques such as acidizing, fracturing, flushing, or re-perforating, any of which can result in debris. [0006] Forms of debris include drilling or perforation debris, debris from cementing operations, and/or mud solids. Naturally occurring debris such as sand, silts or clays can also be present. In some formations shales and shale chunks, pyrites coal and other fragmented sections of formations can be produced. This debris should be quickly removed from the wellbore or formation in order to prevent it from causing a blockage, eroding or damaging production equipment. In some instances the removal of increased volume of debris can substantially enhance production. [0007] Completion or stimulation methods include a method described in U.S. Pat. No. Re. 34,451 to Donovan et al wherein a perforating gun with an external auger is mounted to a tubing string to both aid in clean-up of the debris from the perforations as well as to facilitate the movement of the gun out of the debris. The auger flights create a tortuous path increasing the velocity of produced formation fluids and improves the ability of those fluids to carry debris. Hydrostatic kill fluid is circulated to remove debris and produced hydrocarbons. Thereafter, proppent is pumped down tubing and into the formation. The auger facilitates the removal of the gun packed in the sand. [0008] In U.S. Pat. No. 4,560,000 to Upchurch a well perforating technique actuates a firing mechanism of a tubing-conveyed perforating gun using a pressure difference between at different points in the borehole. The technique obtains the benefit of underbalanced conditions to aid in creating a localized cleansing effect as the formation fluids enter the well casing. [0009] Further, Applicant was part of the development of an aggressive perforating-while-foaming (PWF) production process to increase the production capability of a well. This process has gained wide usage over the last 4 years within the heavy oil industry, specifically wells drilled into unconsolidated sandstone formations. This method produced more sand in a shorter period of time than other more traditional methods. It is strongly suspected that this immediate removal of sand is linked to the superior performance of these wells. A perforating gun is tubing-conveyed down an underbalanced well. The gun is detonated using a drop bar and remote trigger. Foam is almost simultaneously injected and continuously circulated through the wellbore, carrying with it debris from the formation. [0010] Although continuous circulation of foam effectively removes debris from the wellbore in the prior art process, the remote trigger can create un-safe work practices as a result. As well, drop-bars are not considered practical in highly deviated wells since the bar may not reach the bottom. Upchurch relies solely on formation pressure to clean out the wellbore, which can be insufficient in low pressurized formations and can prevent comprehensive elimination of debris from the wellbore. Donovan's method is also dependent on formation pressure to clean out the perforation debris from the wellbore, but is aided by the auger blades. Removal of wellbore debris is not a controlled factor in either case. If debris is not completely removed from the wellbore, it may block perforations, limit production, damage production equipment, or plug the outside or the inside of the production tubing reducing, partially or totally restricting production. In such instances, well clean-out procedures would be repeatedly required at a large expense. SUMMARY OF THE INVENTION [0011] A process is described for creating openings in a well casing and which substantially and immediately accommodates clean-up and production of debris. In a preferred embodiment, a pressure-actuated perforating gun is fired adjacent a zone in the formation to be perforated for forming openings. Substantially simultaneously, a fluid is continuously injected through an auto-vent near the openings and is circulated up through a wellbore at a sufficient velocity or elutriation rate overcome settling of debris and therefore to remove and lift debris from the formation. Optionally, an uphole foam injection means or port can aid in adjusting the hydrostatic head above the perforating gun. The tubing string extends sufficiently above the wellbore at surface to enable lowering of the tubing string and downhole injection means or port to below the openings for enhanced removal of debris. [0012] In a broad aspect, a process for creating openings between a wellbore and a formation comprises running-in a tubing string into the wellbore to position a perforating gun adjacent a perforating zone, pressurizing to a specific pressure so as to: fire the perforating gun and produce openings between the wellbore and the formation, and to automatically actuate a downhole injection means, and thereafter injecting fluid therethrough at a sufficient velocity or elutriation rate to convey debris from the wellbore by circulating the fluid out through the downhole injection means into the wellbore to surface. It is preferable to lower the tubing string during circulation so as to re-position the location of the downhole injection means to below the openings. Typically thereafter the tubing string is then removed. [0013] In another broad aspect, an apparatus for creating openings between a wellbore and a formation comprises a tubing string in the casing and extending downhole from surface for positioning a perforating gun adjacent a perforating zone and forming an annulus between the tubing string and the casing, a downhole injection port located on the tubing string for injection of fluid at an elutriation rate so as to continuously remove debris from the wellbore, and means to pressurize the tubing for firing the perforating gun and opening the downhole injection means. An uphole foam injection system or means can be located on the tubing string for cleaning out the well and displacing wellbore fluid to create a desired fluid level. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIGS. 1 a - 1 b are simplified cross-sections of a wellbore illustrating apparatus run-in on a tubing string for placement of a perforating gun adjacent a formation before firing and for injection fluids, respectively; [0015] FIGS. 2 a - 2 g are a series of schematics of stages of the methodology according to one embodiment of the invention; and [0016] FIG. 3 a - 3 c are flowcharts of some steps of an embodiment of the invention according to FIGS. 2 a - 2 g and illustrating some optional embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] With reference to FIG. 1 a, in a preferred embodiment, it is desirable to create openings 10 in a well casing 12 of a wellbore annulus 14 or wellbore 16 adjacent an underground formation 18 . Herein, the openings 10 are more conventionally referred to as perforations 20 which enable communication between the wellbore 16 and the formation 18 through the casing 12 . Generally, the perforations 20 are created by firing a perforating gun 22 in the wellbore 16 . Debris generally exists in the formation and in the casing which results from operations including drilling or perforation debris, debris from cementing operations, and from mud solids. Naturally occurring debris such as sand, silts or clays can also be present in the formation. In some formations shale, shale chunks, pyrite, coal and other fragmented particles of the formation can be produced. [0018] As shown in FIG. 1 b and FIGS. 2 c and 2 d, debris is removed by substantially immediately commencing to inject and circulate a fluid 24 at sufficient velocities or rates so as to overcome settling velocities of some or substantially all of the debris and lift this debris to surface 26 . Such rates are termed herein as elutriation rates. [0019] Fluids 24 are chosen for their elutriation characteristics, such as density, viscosity, and flow velocities as well as how they interact with wellbore fluid 46 and formation fluids 66 . The possibility of formation damage should always be considered when choosing a fluid 24 . Fluid 24 options can include low density foams, gases, or liquids. [0020] As shown in FIGS. 1 a, 1 b, the formation 18 and wellbore 16 are prepared for an aggressive completion or stimulation techniques using a preferred embodiment of the present invention. A suitable wellhead configuration comprises a spool 28 having a fluid and debris outlet 30 providing communication with the wellbore 16 , a blow-out preventor (BOP) 32 and a pack-off 34 at a wellhead 36 , and a fluid injection inlet 38 . [0021] With reference also to FIGS. 2 a - 2 g and FIGS. 3 a - 1 c, a completion is prepared comprising a tubing string 40 fit at its distal end with the pressure-actuated perforating gun 22 set to fire at a specific pressure. A downhole injection means or port 42 is also set to open or burst at that specific pressure. The downhole injection port 42 is located uphole of the perforating gun 22 . Preferably the downhole injection port 42 is a tubing drain in combination with a firing head of the gun 22 . An example of such a device is the Chameleon, Absolute Pressure Vented Firing Head available from Explosives Limited, Canada. The firing head utilizes fluid pressure to actuate a piston, which actuates the gun and which opens a vent sleeve, which opens the downhole injection port 42 . [0022] The tubing string 40 is made up with conventional components to assist in establishing a tubing tally and the like. [0023] The apparatus enables injection of fluid 24 for lifting debris from the wellbore 16 such as when there is not sufficient formation production volume or pressure to remove the debris or where the debris has a high enough density to be unaffected by usual flow of formation production fluids. Circulation of a suitable fluid 24 can be implemented providing enhanced lift. Such fluid 24 is circulated at sufficient velocity, viscosity and density or elutriation conditions and rates to remove the debris. Thus it is understood that the fluid removing debris being the fluid flowing up the wellbore to surface can comprise injected fluid 24 or a combination of production fluid from the formation and injected fluid 24 . [0024] Generally, a fluid level 62 is established above the perforating gun 22 . Circulation of fluid 24 is established through the fluid injection inlet 38 at the surface 26 and wellbore fluid 46 and fluid 24 are recovered through the spool 28 at the surface 26 . [0025] At FIG. 2 a and step 100 of FIG. 3 a ( FIG. 3 a, 100 ), if the well is a good candidate for the operation, the tubing string 40 is run in FIG. 3 a, 101 and preferably positioned FIG. 3 a, 102 in the wellbore 16 such that the perforating gun 22 is located across from a zone 60 to be perforated and is covered by some wellbore fluid 46 . Of course, safe procedures must be used in a completions operation or stimulation technique including proper tubing string entry techniques. The tubing string 40 is packed off above the wellbore 16 , as shown in FIGS. 1 a, 1 b. [0026] As shown in FIG. 2 b and FIG. 3 b at A, if the desired fluid level 62 exists FIG. 3 a, 103 , the tubing string 40 is pressurized using pressurizing means and the perforating gun is actuated. The fluid level 62 creates a minimum hydrostatic pressure above the perforating gun 22 allowing maximum inflow from the formation once the casing 12 and formation 18 is perforated, but covers the perforating gun 22 to keep it from splitting. [0027] The tubing string 40 is pressurized FIG. 3 b, 104 to a first and specific pressure for actuating a firing head 54 of the perforating gun 22 and forming perforations 20 . A pump, or optionally, pressurized gas may be used to apply pressure in the tubing string 40 . Activation of the perforating gun 22 is not affected by its orientation in the well casing 12 . An explosion 64 creates perforations 20 in the well casing 12 between the wellbore 16 and the reservoir or formation 18 for recovery of formation fluids 66 . [0028] The specific pressure, such as due to the firing of the firing head 54 of the perforating gun 22 , also opens the downhole injection port 42 enabling fluid communication therethrough with the wellbore 16 . [0029] At FIG. 3 b, 105 if a misfire occurs, or the downhole injection port 42 does not open, or opens but the pressure activated firing head 54 does not fire, then the tubing string 40 needs to removed and the problem diagnosed FIG. 3 b, 106 . If required, downhole injection port 42 and firing head 54 are serviced or replaced. The tubing string 40 is run in hole and the process starts again. [0030] As shown at FIG. 2 c, circulation of the fluid 24 conveys or aides the conveyance of the debris up the wellbore 16 with any production fluids to the surface 26 for removal of substantially all debris. [0031] Turning to FIG. 2 d and to FIG. 3 c, 108 , when circulating fluid 24 and for more effective removal of the debris, the tubing string 40 is slowly lowered so that downhole injection port 42 is below the perforations 20 . At FIG. 2 e and FIG. 3 c, 109 , it can be desirable in some instances to stroke, or lower and raise, the tubing string 40 periodically to prevent lodging of the debris and sand flowing into the wellbore 16 between the tubing string 40 and well casing 12 . This action can continue until sufficient debris has been successfully removed. [0032] Once the operation is complete and sufficient debris has been removed from the wellbore 16 , the well's productivity thereafter is increased. [0033] At FIG. 2 e and FIG. 3 c, 110 the tubing string 40 is then raised to elevate the perforating gun 22 above the perforations 20 . At FIG. 2 f and FIG. 3 c, 111 , one of a variety of techniques can be used to apply sufficient hydrostatic head to kill the well before safely pulling FIG. 3 c, 112 the tubing string 40 from the wellbore 16 . Typically the methodology for killing the well is tailored to the particular well and can include simply diminishing fluid 24 circulation to allow formation fluid 66 production to fill the annulus 14 and kill the well or to more aggressively load up the wellbore with suitable wellbore fluid 46 . [0034] At FIG. 2 g, and as an objective of rehabilitating the formation 18 , a production string 68 with a production pump 70 can be run in to re-establish production from the treated well. [0035] In an alternate embodiment, and returning at FIG. 3 a, 103 if the fluid level 62 is deemed inappropriate, and as shown in FIG. 2 b the hydrostatic head may be adjusted. If the fluid level is too low FIG. 3 a, 103 ,B, conventional wellbore fluid 46 can be added FIG. 3 b, 200 to the wellbore 16 for increasing or creating an optimal fluid level 62 by adding wellbore fluid 46 down the annulus. [0036] In another embodiment of the invention, at FIGS. 2 a, 2 b and FIG. 3 a, 103 ,C it may be desirable to reduce the hydrostatic head above the perforating gun 22 . An optional uphole injection means or port 44 is located uphole of the downhole injection port 42 . The uphole injection port 44 is preferably a conventional rotational valve 48 . The rotational valve 48 is strategically located to establish the desired fluid level 62 uphole of the downhole injection port 42 and the perforating gun 22 . [0037] In FIG. 2 a and FIG. 3 a, 101 , the tubing string 40 is lowered into the wellbore 16 with the rotational valve 48 in the open position. If the well has not been previously cleaned out, or if too much hydrostatic pressure exists, at FIG. 3 a, 102 a well depth 56 is tagged and low density foam or suitable fluid can be circulated through the rotational valve 48 to displace any wellbore fluid 46 to create the desired fluid level 62 . The rotational valve 48 can be positioned at other locations in the wellbore 16 and fluid 24 circulated FIG. 3 b, 300 to remove wellbore fluid 46 above the rotational valve 48 , resulting in the desired fluid level 62 . Thereafter, the perforating gun 22 may need to be re-positioned to align with the zone 60 to be perforated. Accordingly, at FIG. 2 b and FIG. 3 b, 301 , the tubing is rotated to close the rotational valve 48 , discontinuing any foam injection and creating a continuously sealed tubing string 40 for pressurizing. [0038] The preferred fluid 24 is low density foam. Inherently, foam has a high viscosity at low shear rates making it extremely useful as a circulating medium in low pressure reservoirs. These properties minimize fluid loss to the formation and reduce needed annular velocities yet provide sufficient debris elutriation with high lifting capability at minimum circulating pressures. Circulation conditions, including foam generated with natural gas or nitrogen instead of air, can be used to clean out higher pressure wells. [0039] Alternatively, production fluids can also be used. A variety of natural and process additives or polymers are available to increase the lifting, carrying and suspending capability of the fluid. [0040] It will be readily apparent to those skilled in the art that many variations, application, modifications and extensions of the basic principles involved in the disclosed embodiments may be made without departing from its spirit or scope. [0041] As suggested in FIG. 3 a at 100 , some wells are better candidates than others for this process, and while this process was developed for the criteria described below, is not limited to these applications which include: [0042] Sand production initiation in stubborn sand formations for cold heavy oil production with sand, [0043] Known drilling damage completions, [0044] Enhanced and rapid drainage geometry development, and [0045] Enhanced initial and cumulative production.

Openings are created between a wellbore and a formation by firing a perforating gun adjacent to a zone in the formation and the production fluids are produced along with any formation debris. A tubing string extending to the formation is pressurized to actuate the perforating gun and simultaneously to actuate a downhole injection port. Substantially immediately thereafter fluids are injected into the wellbore near the openings and circulated to the surface for the removal of debris and the production of the formation fluids. An optional and uphole injection port can be used to adjust the hydrostatic head above the perforating gun with the removal or addition of fluid prior to actuation. The tubing string extends sufficiently above the wellbore at surface to enable lowering of the downhole injection port below the openings during fluid circulation for enhanced removal of debris.

[0001] This application is a continuation-in-part of, and claims priority from, U.S. patent application Ser. No. 09/847,614, filed on May 2, 2001, entitled “A Combined String Line Anchor and Plumb Bob,” the disclosure of which is incorporated herein by this reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to construction and carpentry equipment and tools, and more particularly to anchoring devices for string/chalk lines and/or to plumb bobs. In particular, this invention relates to a protector and holder for a pointed, multifunction tool that serves both as a chalk line anchor and as a plumb bob. [0004] 2. Related Art [0005] In building construction and carpentry projects, alignment strings and chalk lines are frequently used to confirm or establish straight lines. Such string or line systems have one portion that serves to store the unused portion of the string, e.g. a simple ball of string or, as is often the case, a reel of some sort to pay-out and pay-in the line. The other “free” end of the line is usually held by an assistant or anchored by a mechanical device. Such mechanical devices typically include a nail, an awl, or a stickpin, for example. Frequently, commercial chalk lines include an L-shaped hook with an eyelet tied to the line's free end. The hook is used to anchor the line over the edge of a workpiece. After the chalk line is properly positioned, the line is plucked near its center to cause a chalk mark to be left on the surface of the underlying material. [0006] All of the above-mentioned anchoring devices see considerable use at construction job sites. The stickpin is one of the more commonly-used string line anchoring devices. These pins are about the size of an adult finger and have the general shape of the body of a dart (without feathers). The forward end of the stickpin, as in a dart, includes a highly sharpened needle like point. In use, the string is tied around an annular groove in the stickpin, the pin is pressed by hand into the work surface and the line is then looped around the needle portion immediately adjacent to the work surface. The other end of the line is then pulled to tighten the string against the stickpin. The needle portion of the stickpin is typically formed from a high strength steel so that it may be pushed by hand, without damaging the point, into a variety of non-metallic materials, such as wood, plywood, sheet-rock, etc. [0007] Plumb bobs are also frequently used by carpenters and other construction industry professionals. As is well known, a plumb bob is used to determine the “plumbness” or verticality of a wall, stud column, etc. It also is used to vertically transfer a point at one elevation to another elevation. [0008] In laying out construction projects, plumb bobs are frequently used in concert with string lines and chalk lines. The instant inventor has previously invented combined string line anchor and plumb bob tools, such as in U.S. Pat. No. 5,720,113 (issued Feb. 24, 1998) and in the application from which this application claims priority, Combined String Line Anchor and Plumb Bob, Ser. No. 09/847,614. These tools integrate features of a string/chalk line stickpin anchoring device and a plumb bob, to increase the efficiency of the carpenter and reduce overall expenses to the project. [0009] In U.S. Pat. No. 5,720,113 (“'113”), the multi-function tool has a point at its distal end, and a recess and clamping system for mounting on the tool an L-shaped hook of the type conventionally used for attaching a string line over an edge of a work-piece. The '113 tool includes a channel through the proximal end of the tool so that the string line may extend out of the tool at the axial centerline, and a cap on the proximal end that may be removed to reveal the channel, and may be tightened onto the tool to move a slidable jaw to hold the hook in place in the tool. [0010] The tool of Ser. No. 09/847,614 (“'614”) includes an external channel system through which the string line may extend to exit the tool at the axial centerline of the tool. In addition, the '614 tool includes an adjustable pointed spike that may be moved axially to protrude various amounts out from the body of the tool. This adjustability feature allows the tool body to serve as a fixed stop for the insertion of the needle into materials of differing hardness so that the sharpened spike is not inserted into the wood or other material farther than is needed to satisfactorily anchor the string. Also, the adjustability feature reduces the risk of breaking the point when it is inserted too far. If the sharpened spike is broken, it may be removed from the tool and replaced with another adjustable spike, further increasing the efficiency of the carpenter and decrease his/her equipment costs. [0011] Thus, the integrated string line anchoring device and a plumb bob provides a simple, but useful, economical, and efficient tool that is reusable and effective for a long period of time. As a means of protecting the tool and preventing dulling or breakage of the tool point, and preventing injury by the tool point, a cover or sheath for the tool is needed. The instant invention meets this need, in an effective, economical, and easily-used sheath that allows the tool to be safely and comfortably carried in a tool box, on a chalk box, or by other means. SUMMARY OF THE INVENTION [0012] This invention comprises a sheath for a pointed tool, such as a combination string line anchor and a plumb bob. The sheath serves as a cover for the point of the tool, a protector for the tool in general, and a system for connecting/mounting the covered tool on a chalk box or other container or workplace item. In this Description and in the claims, the terms “string line” or “string” includes strings, cables, cords, strips, lines, or other elongated flexible members for attachment to the tool, and used with or without chalk or other materials and substances. In the Description and in the claims, the term “pointed spike” includes the preferred needle-like member, but also may be other sharpened elongated members. [0013] The sheath is generally elongated and comprises an internal cavity with a spike-receiving portion for receiving the distal (forward) end of the tool including the pointed needle or spike, and a body-receiving portion for receiving the central body of the tool. The sheath also includes a lock system that secures the tool in the sheath until the user purposely releases the lock to remove the tool. The sheath preferably includes a base with a generally planar outer surface for resting on an object or for attachment to a chalk box or other surface. The sheath preferably includes a slot for the string line that allows the string line to exit the sheath to extend to a chalk box or a take-up reel and that helps prevent tangling of the string line. [0014] By inserting and locking the tool in the invented sheath, the point of the tool is much less likely to become dull or broken from abrasion or impact by nails, other tools, or other objects in a tool box, nail box, or vehicle bed, for example. Also, when the sheath covers the point, the tool is unlikely to hurt people, animals, or materials and surfaces. With the tool secured via the sheath to a chalk box, for example, the tool is easily located when needed and is kept close to the equipment with which it is normally used. [0015] A preferred feature of the sheath is that it is sized and shaped in such a way that the tool will not fit or lock into the sheath if the point spike or needle of the tool extends out from the tool beyond a certain length. This way, the sheath may be designed to cooperate only with a tool that has a spike sized or adjusted to what may be considered a relatively safe length. [0016] These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed descriptions and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0017] [0017]FIG. 1 is a rear perspective view of one embodiment of the invented sheath. [0018] [0018]FIG. 2 is a front perspective view of the sheath of FIG. 1, with one embodiment of a combined anchor and plumb bob tool inserted and locked into the sheath. [0019] [0019]FIG. 3 is a rear perspective view of the sheath of FIGS. 1 and 2, with the tool of FIG. 2 distanced from the sheath. [0020] [0020]FIG. 4 is a rear perspective view of the sheath of FIGS. 1 - 3 , with the tool of FIGS. 2 and 3 inserted and locked into the sheath. [0021] [0021]FIG. 5 is a rear perspective view of the sheath of FIGS. 1 - 4 , attached to a top surface of a carpenter's chalk box. [0022] [0022]FIG. 6 is a rear perspective view of the sheath of FIGS. 1 - 5 , attached to a side surface of the carpenter's chalk box. [0023] [0023]FIG. 7 is a top view of the sheath of FIGS. 1 - 6 . [0024] [0024]FIG. 8 is a side view of the sheath of FIGS. 1 - 7 . [0025] [0025]FIG. 9 is a bottom view of the sheath of FIGS. 1 - 8 . [0026] [0026]FIG. 10 is a side, cross-sectional view of the sheath of FIGS. 1 - 9 , with the tool of FIGS. 2 - 6 shown in cross-section in the sheath. [0027] [0027]FIG. 11 is rear perspective view of the sheath of FIGS. 1 - 10 , at an angle that allows viewing deep into the tool-receiving cavity of the sheath. [0028] [0028]FIG. 12 is an alternative embodiment of a combined anchor tool and plumb bob that may be used with an embodiment of the invented sheath. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0029] Referring to the Figures, there is shown one, but not the only, embodiment of the invented sheath for a pointed tool. In particular, the preferred sheath is adapted to receive, cover, and protect a combination string line anchor and plumb bob tool. While various combination string line anchor and plumb bob tools may be used in the invented sheath, the preferred tool is shown in the Figures as the type described in U.S. Pat. No. 5,720,113 by the present inventor. The combination anchor and plumb bob tool described in U.S. patent application Ser. No. 09/847,614 and portrayed in this application's FIG. 12, or other tools with pointed tips, may also be used with various embodiments of the invented sheath, wherein some adaptation may be made to the sheath or to the tool so that the sizes and lengths of the cavities in the sheath are appropriate and so that the locking system of the sheath catches properly on a recess or protrusion of the tool. [0030] In FIG. 1, there is shown the preferred sheath 10 , in an empty state. The sheath 10 comprises a cavity wall 12 with a front portion 11 and a rear portion 13 , wherein the cavity wall 12 surrounds and defines an interior cavity. The interior cavity comprises a forward cavity portion 14 at the sheath front end (distal end) 15 , a rearward cavity portion 16 generally central between the front end 15 and the sheath rear end (proximal end) 17 , and an opening 18 into the interior cavity at the rearward cavity portion. Forward and rearward cavity portions 14 , 16 and opening 18 preferably lie in series coaxially on the sheath longitudinal centerline or “longitudinal axis.” The forward cavity portion 14 is adapted to receive the pointed end of the tool 50 , particularly, the portion of the pointed spike 52 protruding from the tool body 54 . The rearward cavity portion 16 is adapted to receive the forward end of the tool body 54 so that the generally conical surface 56 of the tool abuts against the front, inside surface of the rearward cavity, herein also called the limiting surface 20 . This surface 20 serves as a stop to limit forward movement of the tool, so that the tool may only be inserted to a certain extent, no matter how small a distance the pointed spike 52 extends from the body 54 . The limiting surface 20 results in a certain location for the tool body 54 along the longitudinal axis of the sheath, which certain location is preferably the proper location for locking of the tool in the sheath by the preferred locking system 40 , as further discussed below. In embodiments in which the spike 52 is adjustable in and out from the body, this limiting surface feature is beneficial as it prevents a tool from being placed in the sheath with the spike 52 extended far outward from the body. While the preferred limiting surface 20 and cooperating tool surface 56 are described as generally conical, they may also be called “conoidal” or “bullet-shaped” as their conical walls are curved as in a conventional bullet shape. Alternatively, other cooperating/mating shapes may be used, which preferably do not allow “wiggle” or “rattling” of the tool in the sheath. [0031] When the tool is inserted into the sheath and locked into place with the generally conical surface 56 against the limiting surface 20 , there is preferably only ⅝ inch of distance from the front tip 60 of the tool body to the forward inner surface 22 of the forward cavity portion 14 . This way, only a maximum of ⅝ inch of spike 52 may protrude from the tool if the tool is to fit in, and lock into, the sheath 10 . A protruding spike length of ⅝ inch is sufficient for nearly all construction materials, and the inventor believes that this adjustment is useful as well as safe, if handled in a reasonable way. With the sheath being designed for this maximum spike protrusion length, the tool is more likely to remain in the relatively safe ⅝ inch maximum spike configuration, so that it is less likely to be used in an unsafe way. If the spike 52 is adjusted outward farther than ⅝ inch, the tool will no longer fit into the preferred sheath 10 . If the spike 52 is adjusted inward to less than ⅝ inch, then the tool may be even safer, and the tool will fit and lock properly into the sheath. [0032] The limiting surface 20 also serves to stabilize the tool inside the sheath, due to the generally conical shape of the surface 20 corresponding to the generally conical surface 56 of the tool. The sheath conical surface 20 preferably curves at least about 200 degrees around the tool, and, more preferably, at least about 260 degrees. The embodiment shown in the Figures features a rearward cavity portion wall that extends about 280 around the tool. Once the tool is in place in the sheath, these closely adjacent and curved surfaces 20 , 56 tend to prevent movement transverse to the longitudinal axis, and, most preferably, to prevent other than longitudinal movement of the tool in a rearward direction relative to the sheath. [0033] The forward cavity 14 , on the other hand, serves mainly to contain and cover the pointed spike, rather than to stabilize the tool by preventing movement of the tool. Preferably, the spike does not abut or stick into the inner surface 22 . The forward cavity exterior has a generally elongated shape of a smaller width and height than the rearward cavity portion 16 , with a curved top surface 28 and front surface 30 . The inner surface of the rearward cavity preferably transitions smoothly to the inner surface of the forward cavity, so that, during insertion of the tool, if the spike slides along the cavity interior surface, it slides smoothly and is, in effect, guided from the rearward cavity portion into the narrower forward cavity portion. [0034] The locking system 40 preferably automatically engages or sets when the tool 50 is inserted into the sheath 10 , and is released only manually when the user wishes to remove the tool. Preferably, the locking system 22 comprises a latch 41 that catches in a recess 62 in the tool body 54 when the tool slides into place against the limiting surface 20 . The latch is preferably biased into the closed position, that is, biased inward toward the center of the cavity, and, hence, toward the tool surface. The latch preferably “snaps” into the tool recess when the tool is properly in place in the sheath. This way, the tool is easily and conveniently sheathed, and yet is not easily accidently unlocked or dropped out of the sheath. The recess 62 into which the latch 41 snaps is preferably the recess in which the L-shaped hook (call-out 64 in this application) resides when captured in the tool as described in U.S. Pat. No. 5,720,113. The forward wall 65 of the recess 62 is the wall against which the latch abut, thus preventing rearward movement of the tool out of the sheath. [0035] When the user wishes to remove the tool from the sheath, he/she may actuate an unlatching means, such as a manual handle that lifts the latch 41 out of the recess 62 . The preferred lock mechanism comprises a lock member 43 that integrally connects to the top of the cavity wall at a connection region 44 (also called “hinge region”). The lock member 43 extends generally parallel to the longitudinal axis of the sheath above the top surface of the cavity wall 12 . From the connection region 44 , the lock member extends forward to form the handle 45 and rearward to form the latch 41 . The handle 45 extends in a forward direction generally parallel to the top surface 28 of the forward cavity wall, with the handle being distanced from the top surface 28 . Pressure on the handle 45 toward the top surface 28 causes the connection region and/or the cavity wall in that area to flex slightly, so that the lock member 43 pivots generally at the connection region 44 to raise the latch 41 up out of the recess 62 . Thus, the connection region may be considered a hinge, hinge region, or pivotal connection, as the connection region 44 acts to allow the lock member 43 to pivot relative to the rearward cavity wall portion 13 . Tool 50 can then be pulled longitudinally rearward outward of the sheath. When the pressure on the handle is released, the resiliency of the connection region and the cavity wall near region 44 returns the lock member 43 to its starting position, with the latch 41 biased toward the centerline of the sheath to be slightly closer to the centerline than is the inner surface of the rearward cavity portion at the rearward edge of the cavity wall, as best shown in FIG. 10. In effect, a fulcrum is created at or near the attachment of the lock member 43 to the sheath wall (“cavity wall”), allowing the lock member 43 to be biased into the latched position and to pivot to raise the latch into the unlatched position. [0036] One may note that the rear edge 46 of the cavity wall curves, from a position P 1 on the base 48 about ⅓ of the base length from the rear end 17 , upwards and forward to a position P 2 , which is about ⅔ of the base length from rear end 17 and which is forward from the latch end of the lock member. In other words, the lock member extends rearward beyond the rear edge 46 of the cavity wall, so that, in effect, the rearward latch end of the lock member extends rearward past the cavity wall, over the opening 18 , substantially unsupported by, and unconnected to, the cavity wall except at the connection region 44 . This way, the lock member connection region flexes more readily relative to the rest of the sheath, allowing the biased latching and handle-actuated unlatching described above. [0037] The lock member 43 is long enough and extends rearward enough that, when it is biased to pivot the latch end down toward the longitudinal axis of the sheath, the latch end preferably extends down in back of the opening. While the latch end does not necessarily extend into the plane of the opening itself, it may be said to extend “across the opening” when it is rearward and near to the opening. [0038] While various ways of attaching the lock member 43 to the cavity wall may be used, and various ways of forming the biasing means and the pivoting fulcrum may be used, the preferred ways comprise integral molding of the plastic lock member as part of the plastic sheath. This way, the natural resilience of the plastic of the sheath wall, and the lock member connection region may be used to create the biasing that latches the tool in place. Preferably, the sheath is made by molding plastic, preferably a plastic or plastics that are durable and that allow the hinge area (“connection region”) to be sufficiently flexible and resilient to properly operate the lock system. The plastic may be chosen and the thickness and shape of the lock bar attachment area and the adjacent cavity wall areas are chosen so that the flexing moves the latch upwards a sufficient distance to unlatch the tool. The biasing of the latch system into the closed, locked position against the tool wall may comprise the resilience of the plastic that moves the lock bar back into its original position when the handle is no longer being pressed. [0039] While the preferred recess 62 of the tool, into which protrudes the latch 41 , is the recess adapted to also receive the L-hook of the tool from U.S. Pat. No. 5,720,113, other recesses or fasteners for cooperating with a latch or lock on the sheath may be used. For example, an alternative recess, such as the thumb-hole recess of the tool in patent application Ser. No. 09/847,614, may be used, in which case the tool 80 thumb-hole recess 90 may be adapted to have a recess front wall 95 that is transverse to the longitudinal axis of the tool or slanted forward from the top of the wall to the bottom of the wall, so that the latch of the sheath “catches” on the recess wall. [0040] A slot through the cavity wall is preferably provided for passage of the string line from the interior cavity to outside the sheath. As shown in FIG. 3, the string line 47 is normally wrapped around or otherwise connected to the spike 52 when the tool is inserted into the sheath. The string line, therefore, extends rearward from the spike and out of the internal cavity through the slot 49 . Preferably, the slot 49 extends at its forward end to approximately the border between the forward cavity portion and rearward cavity portion, so that the string line 47 may exit the interior cavity without lying between the conical surface 56 of the tool body 54 and the limiting surface 20 of the internal cavity. This way, the string line 47 is not trapped or pinched between the conical surface 56 and the limiting surface 20 . The slot 49 is sized so that the string line 47 is not pinched or pressured to an extent that would, even after repeated sheathings, damage or weaken the string. After passing through the slot, the string line preferably extends into a chalk box 70 or is taken-up by other means, such as being wound on a spool or other object. By positively locating the string line's exit from the sheath and by containing/taking-up the length of the string line in a chalk box or other container or holder, tangling and knotting of the string line are minimized. [0041] As illustrated in FIGS. 5, 6 and 9 , the sheath 10 preferably is adapted for attachment to a chalk box 70 or other object, to further aid in preventing tangling of the string line and/or damage to the sheath and tool that might otherwise occur if the sheath and tool are stored or transported loose in a tool box or vehicle. The preferred adaptation comprises a base 48 positioned underneath the cavity wall that has a generally planar platform surface 72 upon which the sheath may rest. The base 48 includes means for attachment to the chalk box or other object, preferably, an aperture 74 for receiving a screw or bolt that may extend, for example, into an attachment hole 73 in the chalk box. The sheath 10 is preferably fastened by means of a screw (not shown) through the aperture 74 to a carpenter's chalk box 70 , either on a top surface 76 or on a side surface 78 . The string line extends from the slot 49 to the string line hole (not shown) in the chalk box 70 and preferably all of the length of the string line is contained within the chalk box until use of the tool and the string line. This way, the chance of tangles and damage to the string line and to the tool is minimized, and the tool is unlikely to be lost or to do damage to people or materials. Alternatively, the sheath 10 may be molded or otherwise formed as an integral part of a chalk box 70 or tool box, for example. [0042] Preferably, the base 48 is sized to provide a stable platform for the sheath. The base 48 preferably extends forward beyond the front portion 11 of the cavity wall to be the frontmost extremity of the sheath. The base 48 preferably extends rearward beyond the rear edge 46 of the rear portion 13 of the cavity wall to be the rearmost extremity of the sheath. Also, the base 48 extends transversely to the longitudinal axis to extend at least underneath, or out past, both sides of the sheath cavity wall. [0043] With the tool 50 housed in the sheath 10 attached to the chalk box 70 , the tool may be easily withdrawn from the sheath, as detailed above, by pressing on the handle 45 and pulling out the tool. Because the sheath is secured to the chalk box, the tool may be easily removed without the sheath tipping over or moving during the operation. The tool 50 may then be moved away from the chalk box 70 to pull the string line out of the chalk box, coated with chalk, for use. Use of the tool, either as an anchoring device for chalk line marking or as a plumb bob, may be done according to the techniques described in U.S. patent application Ser. No. 09/847,614, from which this application claims priority and which is incorporated herein, and/or described U.S. Pat. No. 5,720,113. [0044] The inventor envisions that other tools, and especially other combined anchor and plumb bob tools, may be used in the invented sheath. Some modification to the sheath may be necessary, for example, to lengthen or adapt the locking mechanism. Or, some modification to the tool may be necessary, for example, to supply a recess or other structure for cooperating with a locking system to retain the tool in the sheath. [0045] Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.

Embodiments of a sheath for a pointed tool are described, which tool may be a combination string/chalk line anchor and plumb bob. The sheath includes a cavity for housing the pointed needle or spike that extends out from the combination tool, and a cavity for at least partially encircling the body of the tool. A locking mechanism is included to secure the tool in the sheath until removed is desired. The sheath may include a system for attaching it to a chalk box, and a slot defining an exit-point for string line to extend out from the sheath to the chalk box or other container or spool.

FIELD OF THE INVENTION This invention relates to automatic valves for coffee makers and the like, and more particularly, is concerned with a magnetically actuated valve which opens and closes automatically in response to temperature. BACKGROUND OF THE INVENTION Automatic coffee brewers are well known in which water is preheated in a tank or vessel into which a predetermined quantity of cold water has been stored. When the water reaches the desired brewing temperature, it is released from the vessel and allowed to percolate down through the ground coffee into a pot or other container from which the fresh brewed coffee is poured. Two different types of valves have been used for releasing the water from the first vessel after it reaches the desired temperature. One type of valve uses a bimetal material for opening the valve when it is heated. The second type is a snap-action device also using bimetal which operates an over-center leverage system, allowing the valve to remain fully closed until the desired temperature is reached, at which time the valve snaps completely open. Both types of valves have exhibited unsatisfactory operating life when immersed in hot water due to a combination of electrolysis and lime deposits which cause failure or malfunction of the valve after a relatively short period of use. Thus there has been a need for a valve which exhibits a much longer operating life but which is inexpensive to manufacture and install. SUMMARY OF THE INVENTION The present invention is directed to an improved temperature sensitive valve for use in coffee brewers, or the like, which is sufficiently simple to manufacture and inexpensive to use and which nevertheless provides a high level of reliability. This is achieved by providing a valve for releasing heated fluid from a vessel when the fluid reaches a predetermined temperature, the valve comprising a valve body of nonmagnetic material adapted to be mounted in the bottom of the vessel, the valve body having a passage extending vertically for draining fluid from the vessel. An annular valve seat member mounted in the passage is made of a thermal-sensitive magnetic material which changes from a ferromagnetic state to a paramagnetic state as the temperature increases above a predetermined value, called the Curie point. A movable plug member positioned in the passage below the valve seat includes a permanent magnet for magentically attracting the plug to the valve seat member to close off the flow of fluid through the passage. The magnetic attraction is drastically attenuated at the Curie temperature when the valve seat material changes to the paramagnetic state, thus allowing the plug member to move away from the valve seat and the heated fluid to flow out of the vessel. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the invention reference should be made to the accompanying drawings, wherein: FIG. 1 is a cross-sectional view of a coffee maker incorporating the valve of the present invention, the valve being enlarged for clarity; FIG. 2 is a partial view showing the top of the valve; FIG. 3 is a sectional view taken on the line 3--3 of FIG. 1; and FIG. 4 is a sectional view taken on the line 4--4 of FIG. 1. DETAILED DESCRIPTION Referring to FIG. 1 in detail, there is shown a conventional coffee brewer including a pot 10 forming the lower section of the coffee brewer in which is nested a coffee basket 12. The top of the basket 12 has a radially projecting rim 14 which rests on the top edge of the pot 10. Ground coffee is placed in the bottom of the basket 12, as indicated at 16. The basket is perforated to allow water to pass down through the coffee and drip into the pot 10. A water tank or vessel 18 fits on top of the rim 14. The vessel 18 has a bottom wall 20 in which is mounted an automatic valve assembly, indicated generally at 22. Suitable heating means, such as a Calrod unit, indicated at 24, may be used to heat the water in the vessel 18. The valve assembly 22, as hereinafter described in detail, operates to open when the temperature of the water in the vessel reaches the desired level of slightly below the boiling temperature. The valve assembly 22 releases the water in the vessel allowing it to percolate down through the coffee grounds and into the pot. The valve assembly 22 includes a cylindrical valve body 26 which may be integral with the bottom 20 of the vessel 18, or may be welded or otherwise secured to the bottom 20. The cylindrical valve body has a vertical passage 28 which is closed at the lower end by a bottom wall 30. A sleeve portion 32 of the valve body projects upwardly from the bottom wall 30 along the central axis of the passage 28. A plurality of radial openings 34 allow discharge of fluid from the passage 28 into the interior of the coffee basket 12 from the vessel 18 when the valve is open. The size and number of the openings 34 can be varied to control the rate at which water is discharged. A valve for a 60-cup unit, for example, requires a much higher discharge rate than a 4-cup unit. An annular valve seat member 36 is press-fitted or otherwise secured in the top of the valve body 26. The annular valve seat member has a central fluid discharge opening 38 axially aligned with the passage 28. A vertically movable valve plug element, indicated generally at 40, is positioned inside the passage 28 below the valve seat member 36. The valve plug assembly includes a pin or shaft 42 which is journaled in the sleeve 32 and is freely movable axially or rotatably in the sleeve 32, which acts as a guide. An annular magnet 44 is secured to the shaft 42. A washer 46 made of elastomeric material, such as a flexible silicone rubber, is supported on the end of the shaft 42 above the magnet 44. The washer 46 is frusto-conical in shape, the upper end being of smaller diameter than the opening 38. The valve is assembled by first inserting the shaft 42, with the magnet 44 and washer 46 in place, in the sleeve 32 and then pressing the valve seat member 36 into the upper end of the cylindrical portion 26 of the valve body. The valve seat member 36 is molded or otherwise formed from a thermal ferrite material which has a Curie temperature of approximately 85° C. Above this temperature the thermal ferrite material is in a paramagnetic state, that is, it loses its magnetic properties. Such thermal ferrite materials are commercially available in specified shapes and sizes with the desired Curie point. The magnet 44 is in turn molded of a ferrite material having a high permeability and whose Curie temperature is well above the normal operating range of the valve. The magnet 44 is magnetically polarized in a direction transverse to the vertical axis of the shaft 42, that is, the magnet is polarized with the north and south poles at diametrically opposite positions. It has been found that this direction of polarization provides superior operation of the valve, although axial polarization may be used. At temperatures below the Curie point, magnetic attraction between the magnet 44 and valve seat 36 is sufficient to lift the plug 40 toward the valve seat, in which position the conical washer 46 wedges into the opening 38 in the valve seat member 36. This closes the valve, preventing water from escaping from the vessel 18 into the coffee basket 12. As the water in the vessel 18 is heated, the water being in direct contact with the valve seat 36 causes the valve seat member to be heated above the Curie temperature. This causes the valve seat member 36 to lose its magnetic properties so that the plug 40 is no longer supported by the magnetic attraction between the magnet 44 and the valve seat member 36. This causes the plug 40 to drop down until the magnet 44 rests on top of the sleeve 32, allowing the water to escape from the vessel 18 through the passage 28 and radial openings 34 into the coffee basket 12. After the water is drained out the vessel 18 and the heating element 24 is turned off, the valve seat member 36 cools below the Curie temperature, at which point the plug 40 is lifted into the closed position by magnetic attraction between the magnet 44 and the valve seat member 36. From the above description it will be seen that a temperature sensitive valve has been provided having a single moving part. The valve can be readily made of materials which are non-corrosive and the tolerances and general design in such that lime deposits will not interfere with the function of the valve. One advantage of the present valve is that it can be constructed entirely of non-metallic materials, the ferrite being a ceramic material. This enables the valve to be used in coffee makers, or the like, designed for heating by microwaves, as in a microwave oven. Another advantage is that the operating temperature of the valve can be regulated in one of two ways. One way is to select a ferrite with a different Curie temperature. However, to a limited extend the operating temperature can be modified by changing the gap between the magnet and the ferrite. This gap, being controlled by the shape of the conical washer 46, can be easily modified by changing the thickness of the washer, for example.

A temperature sensitive valve in which the annular valve seat is made of a thermal sensitive magnetic material having a Curie temperature that is of a preselected value. A vertically movable valve plug is positioned below the valve seat and contains a permanent magnet which normally urges the plug up into the valve seat to close the valve, but which allows the valve to open when the temperature of the valve seat exceeds the Curie temperature.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a device for activating an opening mechanism and/or a closing mechanism for lockable moving parts on vehicles. The device includes a manual actuator which, upon its actuation, acts on a switch and switches on a drive for opening or closing the movable vehicle part. Such a drive can belong to a closure which is embodied as a rotary latch. The rotary latch is secured by a locking pawl in the locking position and, upon activating the actuator, is transferred into an opening position. Such a device is, for example, used at the rear hatch of a motor vehicle. 2. Description of the Related Art In the known device of this kind (DE 34 40 442 A1) the actuator is a pushbutton which is arranged in a hole in the outer skin. In order to secure the pushbutton in its initial position, a pressure spring is required. In order to protect the mechanism against dirt and moisture, the pushbutton is covered by a foil and sealed. Upon actuating the pushbutton, a ball is moved which acts on a contact maker of a switch which is arranged adjacent to the pushbutton. This known actuator comprises several components which must be manufactured separately and assembled with one another. Despite the elastic cover, dirt and moisture can enter the hole of the outer skin. Moreover, in devices of the kind mentioned further decorative elements can be provided before, on and/or within the outer skin of the vehicle which serve for embellishing or provide a visual information content. A typical example for this is a company emblem. SUMMARY OF THE INVENTION In a device of the latter kind (DE 197 22 503 A1) the decorative element is comprised of a company emblem which is supported rotatably on the outer skin which in its initial position covers a lock body relative to the exterior. The company emblem can be transferred into a release position in which it releases the lock body or another actuator for the vehicle part. In the release position, the company emblem at the same time functions as a grip element in order to completely open the vehicle part, for example, a rear hatch of the vehicle. After actuation of the means, it was necessary to return the company emblem into its initial position. This is cumbersome. It is known to arrange push buttons for interior gauges of motor vehicles under an elastic plastic skin (DE 42 13 084 A1) and to actuate the switches through the skin. The elastic skin serves as a cover of the steering wheel or an arm rest in the vehicle interior. Such a plastic skin cannot be used for the external actuation of doors or flaps of a vehicle. The external actuator of a door must be able to withstand impacts and must be weathering resistant. It is moreover known to employ for actuation of switches in an arm rest (WO 97/11473) pressure-responsive resistors which are connected to a control module. The pressure-responsive resistors are arranged on the surface of a foam material laver and the foam material layer is covered by a flexible skin which may have a soft outer layer. Upon pressure actuation on the flexible skin, the foam material layer is compressed and this results in a thickness change of the soft cover positioned above the pressure-responsive resistors. Such soft inner covers of the vehicles are not suitable for external actuators of doors. It is finally also known in the case of inner covers of vehicles (GB 2 161 122 A) to employ membrane switches underneath an elastic foam material layer, wherein the arrangement locations of the switch, for the purpose of visual and touch recognition, are recessed at some locations. The actuation pressure results in a deformation of the recessed locations of the foam material layer which then act on the membrane switch. Such foamed material layers have also been used for rocker actuators or membrane switches (U.S. Pat. No. 5,448,028), wherein projecting areas in the arm rest indicated the position of the switch. This foam material layer was covered by a flexible skin. The pressure actuation resulted in the compression of the laver above the membrane switch or the rocker with regard to its layer thickness which resulted in pressure being exerted onto the switching elements underneath. Such foam material layers which are compressible with regard to their laver thickness are not suitable for the external actuation of doors. Cushions of elastic material, whose exterior however must be covered by a metallic coating, have been used on grips or buttons positioned on the exterior side of doors (FR 2 217 784 A). In the elastic cushions a switch with a contact maker was integrated. The contact maker was supported on a bracket arranged before the cover. The car body of the door in this area was provided with a depression in order to provide space for the hand. The hand compressed the elastic cushion from behind, i.e., from the interior of the depression. Accordingly, the cushion together with the switch integrated therein was pressed against the bracket underneath the cover. This door actuators are comprised of numerous components. This known door actuators form disturbing components projecting from the car body which can easily soil and are difficult to clean. The invention has the object to develop a reliable device of the kind mention above which is embodied inexpensively and is easy to manipulate. The invention has recognized that either the outer skin of the vehicle or a decorative element seated on the outer skin of the vehicle can take over the further novel functions of being the actuator for the switch. According to a first embodiment, a portion of the outer skin itself is used as an actuator for the switch. For this purpose, it is sufficient to make a certain location at the outer skin elastically deformable by pressure loading. This can be realized by a suitable material selection, sizzling or shaping of the outer skin at this location. The outer skin remains smooth at this location relative to the exterior, requires no holes and no inserted parts. It is sufficient to arrange the contact maker of the switch either directly or indirectly within the yielding path of the car body portion. Since holes are no longer required in the outer skin, there are no sealing problems and there is not risk of soiling. In an analog way, according to another embodiment, a portion of the decorative element itself is embodied to be elastically deformable and fulfills thus the function of an actuator for a switch whose contact maker is again arranged directly or indirectly in the yielding path of the decorative element portion. In this connection, according to FIG. 4, it is beneficial to use the configuration of the decorative element in the form os stays in accordance with the decorative function or the visual information function. The decorative element is in fact divided by stays with intermediately positioned penetrations. The invention has recognized that the stays favor the elastic yielding in a certain portion of the decorative element such that this area is particularly suitable in order to serve as an actuator of the switch. This means that a number of components are no longer needed as they were otherwise required for an actuator provided underneath the decorative element. Moreover, the decorative element must not change at all its initial position in order to trigger the actuator. It is sufficient to press down on the corresponding yielding location of the decorative element in order to obtain the desired switch actuation. BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the invention result from the dependent claims, the following description, and the drawings. In the drawings, the invention is illustrated in several embodiments. It is shown in: FIG. 1 a longitudinal section of a portion of the outer skin of a vehicle with the actuating location according to the invention, shown in the rest position; FIG. 2 the device illustrated in FIG. 1 in the situation of pressure actuation; FIG. 3 a first alternative embodiment of the invention, i.e., a longitudinal slot through a portion of a rear hatch of a motor vehicle, shown in the rest position; FIG. 4 the device illustrated in FIG. 2 in the actuating situation; FIG. 5 a further embodiment of the device according to the invention, where the actuatable deformation location is integrated into a company emblem which is seated on the outer skin of a rear hatch of the vehicle, shown in a rest position; FIG. 6 a detail of the device shown in FIG. 5 during its pressure actuation; FIG. 7 the spaced position of the company emblem resulting from the pressure actuation of FIG. 6 and now serving as a hand grip for completely opening the flap; and FIGS. 8 + 9 two modified embodiments of the device illustrated in FIGS. 5 through 7 when the company emblem is in a spaced position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows in a longitudinal section a portion of a rear hatch 10 of the motor vehicle which is secured by a lock, not shown in detail, in the closed position. In order to facilitate opening of the lock, a drive, not illustrated in detail, is provided, for example, an electric motor. For switching on or off this drive, a switch 12 is provided which is connected by lines 35 with the drive. In the usually present closed position of FIG. 1 the drive is inactive. The switch 12 is fastened on a support 36 which is integrated into the structure of the hatch 10 in this configuration. A contact maker 13 of the switch 12 is arranged on the backside 41 of the outer skin 40 and should be, if possible, in contact with the backside 41 . The contact maker 13 in the present case is comprised of a pin which is longitudinally movable in the direction of arrow 16 and, according to its movement, can perform different switching functions within the switch 12 . When the pin 13 is pushed in, the contacts within the switch 12 are closed, and a corresponding switch-on signal is transmitted via lines 35 to the drive. Several switches 12 can be provided at this location or in the neighboring area which are correlated with further functions in the vehicle, for example, for closing the closure when closing the rear hatch. Such switches 12 can also activate additional functions on the vehicle, such as closing or opening of the doors, the windows and the sliding roof of a vehicle. These different functions can alternatively also be triggered by different magnitudes of the pushing-in movement 16 of the contact maker 13 . Between the contact maker 13 of the switch 12 and the backside 41 of the skin, it is also possible to arrange transmission members for the switch actuation so that the switch 12 itself could be fastened at a more beneficial location relative to the outer skin 40 which location is moved farther away. The location 43 of the outer skin 40 which is substantially aligned with the contact maker 13 is elastically deformable relative to the adjoining neighboring area 42 when pressure is exerted there according to the force arrow 20 of FIG. 2 . For short, this location 43 will therefore be referred to in the following as “deformation location” of the outer skin 40 . The actuation situation of the deformation location is illustrated in FIG. 2 and the deformation resulting therefrom is indicated at 43 ′. The yielding path, indicated in FIG. 2 at 29 , results in which the contact maker 13 is arranged directly, as mentioned before. The drive is then activated in the described way. The rear hatch 10 can be transferred in the direction of movement arrow 11 of FIG. 2 into the upwardly folded position, not illustrated in detail. The deformation location 43 is suitably embodied such that upon pressure actuation 20 a defined yielding action is realized. This can be realized by a corresponding shaping of the location 43 and/or by a reduction of the wall thickness 45 of this outer skin 40 . Also, weakening of this deformation location 43 by cutouts in the wall of the outer skin 40 would be conceivable. The center of the deformation location 43 , which is especially effective for the exertion of the pressure 20 , should be marked in a special way at the exposed side 46 of the outer skin 40 . The drive, in the actuation situation of the deformation location 23 ′, can be used for a complete opening of the rear hatch 10 without this requiring an auxiliary manual handling. This should also apply in the case of the other embodiments. The embodiment according to FIGS. 3 and 4 shows a modification of the lock wherein for identifying corresponding components the same reference numerals as in the preceding embodiment of FIGS. 1 and 2 are used. In this connection, the previous description applies. It is sufficient to discuss the differences. The actuator for the switch in the present case is a company emblem 25 with a circular contour 24 which has an elastically deformable portion. The company emblem 25 has a logo which is comprised of several stays 23 , 27 . The stays 23 , 27 fulfill a certain decorative function and can also provide a visual information content and can be comprised of letters and/or an image. Between the stays there are penetrations. In the present embodiment there is even a separating cut 26 between two stays 23 , 27 which make one stay 23 flexible. The stay 23 is fast at one end in the circumferential area 24 , but is flexible at its oppositely positioned free end 28 . The stay 23 fulfills the function of a flexible bar. It is deformed in the direction of arrow 20 ″ of FIG. 4 relative to the neighboring stay 27 , which is in itself rigid, toward the switch 12 and reaches the position 23 ′. This is illustrated in FIG. 4 by the deformation travel 29 . The company emblem is integrated into a neighboring area 22 of the car body. As can be seen in FIG. 4, the company emblem 25 belongs to a modular unit 30 which in itself can be completely pre-assembled and comprises the following components. There is first a mounting plate 17 on whose backside 18 the already mentioned microswitch 12 with its housing is fastened. A guide 14 on the switch housing penetrates a penetration 19 provided within the mounting plate 17 so that the contact-providing pin 13 is positioned at the inner side 31 of the mounting plate 17 . In front of the contact pin 13 a continuous elastic membrane 33 can be arranged, which is illustrated in FIGS. 3 and 4 only by a dash-dotted line and which is a component of the modular unit 30 and extends over the entire inner side 31 of the plate in a sealing way. The company emblem 25 , together with the membrane 33 and a circumferential seal 34 , is fixedly connected to the mounting plate 17 , for example, by screws. Of course, these fastening screws do not impair the flexibility of the afore described yielding location 23 . This modular unit 30 is mounted in the aforementioned neighboring area 22 of the outer skin in a cutout 32 , illustrated in FIG. 4 . When the force exertion 20 of FIG. 4 is finished, the elasticity within the company emblem 25 ensures that the car body location returns from its actuating position 23 ′ again into its initial position of FIG. 3 . This restoring movement can be supported, if needed, also by additional elastic means such as leaf spring. Normally, this is not required, in particular, because the membrane 33 has a certain restoring elasticity. The membrane 33 has in fact the tendency to return into the curved position illustrated in FIG. 3 which is its stable state. It is understood that, instead of a company emblem 25 , other decorative elements on the outer skin of the vehicle can take over the function of the inventive actuator for a microswitch. For example, it is possible to use decorative parts of a vehicle for this purpose. However, suitable would be also designation parts on the vehicle which are provided anyway, for example, the model designation of the vehicle. In the third embodiment of FIGS. 5 through 7, a modular unit 21 comprised of an attachment 50 and an insert 37 is provided, wherein a company emblem 51 is integrated also in the attachment 50 . This modular unit 21 is pre-manufactured and mounted in the neighboring area 22 of the car body. In contrast to the preceding embodiment of FIGS. 3 and 4, the company emblem 51 integrated into the attachment 50 is movable by the same motor 15 which also serves for actuating the lock which is not illustrated in detail. FIG. 7 shows the spaced position 50 . 2 where the attachment 50 has an angle α of approximately 45° relative to the contact position 50 . 1 in FIG. 5 . The insert 37 on the other hand remains stationary. It forms the inner layer of this modular unit 21 , is comprised of elastomeric material, and is seated in a cutout 32 of the outer skin 40 . this inner layer 37 forms an elastic seal and has a central dome 38 in front of the contact maker 13 of a switch 12 which is seated on the support 36 . In a paced position according to FIG. 7, a closing cylinder 48 , which in an emergency situation allows for a key actuation of the rear hatch lock, is accessible through an opening 39 in the inner layer 37 . the closing cylinder 48 is mounted on the support 36 . On the support 36 two levers 47 are connected at 49 . The levers 47 support the attachment 50 . As can be taken best from FIG. 7, the attachment 50 itself is of a multi-layer configuration comprised of the outer company emblem 51 , a membrane 52 arranged at the backside thereof and having elasticity of extension, and a shape-stiff grip plate 53 which is comprised of metal. The company emblem 51 is comprised of a relatively shape-stable material, i.e., plastic, but has penetrations 54 which provide in the central area of this outer layer 51 a sufficient elasticity of flexure. The company emblem 51 is three-dimensional and has penetrations 54 in the relief between the lettering and the image. The penetrations 54 are closed at the backside by the expandable membrane 52 and are thus sealed. The grip plate 53 positioned underneath is seated on the free ends of the levers 47 and has a hole 55 at a defined location. The three layers 51 , 52 , 53 of the attachment 50 are fixedly connected to one another at their periphery 24 . At the central area of the attachment 50 a sufficient spacing is provided between the grip plate 53 and the flexible layers 51 , 52 positioned above. Normally, the contact position 50 . 1 , which is indicated in FIG. 5 by an auxiliary line 50 . 1 , is present where the modular unit 21 is positioned closely at the inner layer 37 within the cutout 32 of the outer skin 40 . In this case, the central dome 38 of the elastic inner layer 37 projects through the hole 55 of the grip plate and, as illustrated in FIG. 5, is aligned with a yielding location 23 of the company emblem 51 . The yielding action is recognizable for the pressure actuation 20 illustrated in FIG. 6 . In the company emblem 51 the yielding location 23 is transferred into the pushed-in position 23 ′ illustrated therein where the dome of the elastic inner layer 37 positioned behind has been pushed into the area of the grip plate hole 55 and thus has suffered a flattening 38 ′. Accordingly, the contact maker 13 is pushed in and the switch 12 actuated. The grip plate 53 limits the pressure actuation 20 of the actuated deformation location 23 ′ according to FIG. 4 . The actuation of the switch 12 activates the drive 15 by means of an electronic control, not illustrated in detail, which drive, as mentioned already above, first transfers the lock of the rear hatch 10 into a ready position for opening. The same motor drive 15 , expediently after a short delay, is also used for movement of the modular unit 50 . This movement is realized via the levers 47 which are pivoted outwardly. This results in the already aforementioned spaced position of FIG. 7 which is indicated therein by the auxiliary line 50 . 2 . Now the grip plate 53 can be engaged from behind by a human hand 5 . 6 in order to transfer the rear hatch 10 in the direction of movement arrow 11 of FIG. 7 into the completely open position. For this purpose, the opening force which is illustrated by the force arrow 57 is provided. From its spaced position 50 . 2 the modular unit 50 is returned manually or by a motor drive into, its contact position 50 . 1 of FIG. 1 . This can also be performed automatically upon closing of the rear hatch. The device according to FIG. 3 to 5 could also be integrated as an immobile attachment 50 or as an insert into the outer skin 40 when the function of a hand grip according to FIG. 5 is not to be utilized. In this case, the grip plate 53 and the lever 47 can be eliminated. however, the outer layer 51 as the company emblem remains in place behind which sealing layers 52 and/or 37 are positioned and which acts through the actuating pressure 20 according to FIG. 4 in the already described way on the contact member 13 of the switch 12 . Should the electrical devices of the vehicle be defective and the switch 12 and the drive 15 therefore not be functioning, the rear hatch 10 can still be opened. The attachment 50 has, as illustrated in FIGS. 5 and 7, in the lower area a rearward cutout 58 which is accessible for the fingertips of a human hand. By a manual pulling action, the levers 47 can then be decoupled from a locking position coupled with the motor 15 and make possible a manual pivoting of the modular unit into the spaced position illustrated in FIG. 7 . As already mentioned, the end face of the closing cylinder 48 , which is normally positioned below the modular unit 50 , is then accessible through the opening 39 of the inner layer 37 and makes possible the opening of the rear hatch, as already mentioned, by means of an emergency key. In FIG. 8 a modification of the device of FIGS. 5 through 7 is illustrated. It is sufficient to only discuss the differences while in other respects the description provided above applies. In this case the levers 47 are connected fixedly to a bearing shaft 59 for common rotation. The shaft 59 is driven by a transmission 16 which is arranged downstream of the motor 15 . The emergency situation described in the preceding embodiment can be applied also in this modification of FIG. 8 . In this case, between the bearing shaft 59 and the transmission 60 a locking coupling is provided which can be, for example, a magnetic coupling which acts by means of permanent magnets. By exerting a sufficiently great opening force, the magnetic coupling is decoupled and the levers 47 reach a “freewheeling” position. In the embodiment of FIG. 9, a drive 61 , modified in comparison to FIG. 8, is illustrated which is comprised of a motor, in particular, an electric motor and a transmission. Here, the output member of the transmission is a tooth rack 62 which engages a gear wheel 63 . The gear wheel 63 is fixedly connected with the levers 47 and pivotable together with them about their connecting location 49 . FIG. 9 shows in solid lines the inserted position 62 of the tooth rack. Its retracted position 62 ′ is illustrated in dash-dotted lines. It is present when the attachment 50 is positioned in the contact position illustrated in the second to last embodiment of FIG. 5 . In this case, in an emergency situation it is possible to manually move away the attachment 50 from the outer skin 40 . For this purpose, it is sufficient to employ a double tooth rack or to employ again the afore described magnet coupling between the movable transmission parts.

The invention relates to a device for activating an opening mechanism for lockable moving parts on vehicles. The device has a manual activator, which acts on a contact sensor ( 13 ) of a switch ( 12 ) for activation purposes. An outer skin ( 40 ) is provided on the vehicle. A part ( 43 ′) of the actual outer skin ( 40 ) is made elastically deformable ( 43 ′) and this part ( 43 ′) is used as the activator for the switch ( 12 ).

This application is a divisional of U.S. application Ser. No. 09/765,168, filed Jan. 18, 2001 now U.S. Pat. No. 6,983,483, which claims the benefit of U.S. application Ser. No. 08/687,285, filed Jul. 25, 1996, and now issued as U.S. Pat. No. 6,216,264, and which claims the benefit of U.S. Provisional Application No. 60/006,889 filed Nov. 17, 1995. FIELD OF THE INVENTION The subject invention concerns apparatus for scheduling the selection of a television program for watching or recording at some future date. BACKGROUND OF THE INVENTION The programming of modern television systems, such as TV schedulers, VCRs, and Satellite Receivers has become more complicated in that the number of available channels has increased dramatically of late. For example RCA® DSS® direct broadcast satellite receivers provide as many as 150 channels to choose from. Heretofore, a user who wanted to record a specific non-regularly scheduled television program such as the airing of a particular movie, would regularly consult a television schedule printed in his local newspaper in the hope that he would eventually find that movie listed. Such a practice may work well when there are only a few television channel schedules to examine, however, it is unlikely that a viewer would be able to examine the complete schedules for 150 television channels each week. Such a task would be daunting even if all of the movies were to be listed separately, as some television program listings do. Consequently, it is felt that as the number of channels increases, the chances of successfully locating a single occurrence of a program (like a needle in a haystack) becomes more and more unlikely. SUMMARY OF THE INVENTION In a television system in which at least program title information for programs which are to be transmitted in the future is transmitted in advance to form a channel guide listing, apparatus is provided for searching the listing for specific user-entered information, and upon successful conclusion to the search, the apparatus schedules the tuning of the desired program, or in the alternative, notifies the viewer of the availability of the program. In those instances where descriptive text accompanies the program listing, apparatus of the invention performs a search of the text for a particular text string which may relate to the title, the star, the director, or the context of the program, among other search criteria. BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 a - 1 c are illustrations of a screen display of a portion of a channel guide, in accordance with one aspect of the invention. FIG. 2 is an illustration of a screen display showing a search request screen in accordance with another aspect of the invention. FIG. 3 is an illustration of a screen display of a portion of a channel guide showing auxiliary program information. FIG. 4 is an illustration in block diagram form of apparatus suitable for use with the invention. FIG. 5 is an illustration of a search request list in accordance with the subject invention. FIG. 6 is an illustration of a screen display useful for entering text search phrases in accordance with the invention. FIG. 7 is a flowchart useful in understanding the invention. DETAILED DESCRIPTION OF THE INVENTION Television systems such as the RCA® DSS® direct broadcast satellite system and Starsight® transmit channel guides for display on the television receivers of subscribers. FIGS. 1 a - 1 c show Program Guide screen displays produced, for example, by an RCA® DSS® direct broadcast satellite receiver system, manufactured by Thomson Consumer Electronics, Inc. Indianapolis, Ind. A user selects a television program from a Program Guide for viewing, by moving a cursor (via operation of remote control up, down, right, and left, direction control keys, not shown) to a block of the program guide screen display which contains the name of the desired program. When a SELECT key on the remote control is pressed, the current x and y position of the cursor is evaluated to derive virtual channel and program time information. In this example of FIG. 1 a , a particular television show, EVENING NEWS has been highlighted for selection by use of the cursor keys on a remote control unit (e. g., 450 R of FIG. 4 ). The highlighting is illustrated by the dark box outlining the title in FIGS. 1 a - 1 c . Normally, upon pressing the SELECT key, the relevant programming data is transferred to a programming unit. However, note the phrase “ENTER ALL OR PART OF A PROGRAM NAME TO SEARCH” which appears at the bottom of FIG. 1 a . In this case the word “HOME” has been entered by a user. Upon pressing the MENU key, a search of the channel guide information is performed for the next occurrence of a television program including the word “HOME” in its title. At the completion of the search, the screen display of FIG. 1 b is generated. Note that a television program on channel 106 entitled “HOME IMPROVEMENT” is now highlighted. If desired, a further search can be initiated by pressing the MENU key again. The result of that further search is shown in the screen display of FIG. 1 c. Note that in FIG. 1 c , a television program on channel 305 , “HOME AND GARDEN” is highlighted, because that title includes the word “HOME”, and thus satisfies the search criteria. The subject apparatus can also perform “substring searching” wherein the keyword (search term) is contained within another word. For example, a substring search on the word HOME would find the movie title “HOMEWARD BOUND”. Similarly, the search can be made case sensitive, or case insensitive, as desired. FIG. 2 shows a “GOPHER PROGRAM” screen display 210 useful for entering text to be searched, and for entering instructions to be executed in the event that the search is terminated. The search entered on screen display 210 will perform the logical “AND” function on the search terms “ZULU” (a movie title) and “MICHAEL CAINE” (one of ZULU'S stars). While a logical “AND” function is shown, logical “OR” and “NOT” functions are also envisioned. In fact, a logical “OR” function could simply be performed by entering the search terms as two different searches. That is, if the search term “ZULU” were entered by itself, the movie “ZULU” AND any television program concerning the ZULU tribe would be selected. If the search term “MICHAEL CAINE” were entered as a separate search, the movie “ZULU” and any other movie starring Michael Caine would be selected. Note from screen display 210 , that when the movie “ZULU” is found, it is to be recorded. That is, after entering the search terms and instructions via screen display 210 , the user does not have to perform any further function (other than ensuring that the VCR has a tape in it) to secure a recording of the movie “ZULU” whenever it is aired. At the proper time the apparatus of the invention will transmit the record commands to the VCR, automatically. Alternatively, the user may have checked the box labeled DISPLAY A “PROGRAM LOCATED” MESSAGE, in which case the show will not be recorded, but rather a reminder will be displayed indicating that the search has successfully terminated upon finding the requested item. FIG. 3 shows a Program Guide screen 310 , including an auxiliary information display 320 . The text of auxiliary display 320 includes the search terms “ZULU” and “MICHAEL CAINE” in the program description. This text will be searched by the GOPHER PROGRAM and the search will come to a successful conclusion. Note that a search of “ZULU” and “STANLEY BAKER” would have been equally successful. It is important to note that not only is the Program Guide text, but also the auxiliary information associated with the television programs, is being searched. As noted above, the channel guide data used by the controller of the subject apparatus to form the above-described interactive or confirmation sentences may be received from a satellite television communication system. FIG. 4 shows such a satellite television communication system in which, a satellite. 400 S receives a signal representing audio, video, or data information from an earth-based transmitter 400 T. The satellite amplifies and rebroadcasts this signal to a plurality of receivers 400 R, located at the residences of consumers, via transponders operating at specified frequencies and having given bandwidths. Such a system includes an uplink transmitting portion (earth to satellite), an earth-orbiting satellite receiving and transmitting unit, and a downlink portion (satellite to earth) including a receiver located at the user's residence. In such a satellite system, the information necessary to select a given television program is not fixedly-programmed into each receiver but rather is down-loaded from the satellite continually on each transponder. The television program selection information comprises a set of data known as a Master Program Guide (MPG), which relates television program titles, their start and end times, a virtual channel number to be displayed to the user, and information allocating virtual channels to transponder frequencies and to a position in the time-multiplexed data stream transmitted by a particular transponder. In such a system, it is not possible to tune any channel until the first master program guide is received from the satellite, because the receiver (IRD, or Integrated Receiver Decoder) literally does not know where any channel is located, in terms of frequency and position (i.e. data time slot) within the data stream of any transponder. A master program guide is preferably transmitted on all transponders with the television program video and audio data, and is repeated periodically, for example, every 2 seconds. The master program guide, once received, is maintained in a memory unit in the receiver, and updated periodically, for example every 30 minutes. Retention of the master program guide allows instantaneous television program selection because the necessary selection data are always available. If the master program guide were to be discarded after using it to select a television program, then a delay of at least two seconds would be incurred while a new program guide was acquired, before any further television program selections could be performed. Once the channel transponder carrying a desired television program is tuned, the data packets containing the audio and video information for that program can be selected from the data stream received from the transponder by examining the data packets for the proper SCID (Service Component Identifier) 12 bit code. If the SCID of the currently received data packet matches the SCID of the desired television program as listed in the program guide, then the data packet is routed to the proper data processing sections of the receiver. If the SCID of a particular packet does not match the SCID of the desired television program as listed in the program guide, then that data packet is discarded. A brief description of system hardware, suitable for implementing the above-described invention, now follows. In FIG. 4 , a transmitter 400 T processes a data signal from a source 401 (e.g., a television signal source) and transmits it to a satellite 400 S which receives and rebroadcasts the signal to a receiving antenna 400 A which applies the signal to a receiver 400 R. Transmitter 400 T includes an encoder 410 T, a modulator (i.e., modulator/forward error corrector (FEC)) 420 T, and an uplink unit 430 T. Encoder 410 T compresses and encodes signals from source 401 according to a predetermined standard such as MPEG. MPEG is an international standard developed by the Moving Picture Expert Group of the International Standards Organization for coded representation of moving pictures and associated audio stored on digital storage medium. An encoded signal from unit 410 T is supplied to modulator/Forward Error Corrector (FEC) 420 T, which encodes the signal with error correction data, and Quaternary Phase Shift Key (QPSK) modulates the encoded signal onto a carrier. Uplink unit 430 T transmits the compressed and encoded signal to satellite 400 S, which broadcasts the signal to a selected geographic reception area. The signal from satellite 400 S is received by an antenna dish 400 A coupled to an input of a so-called set-top receiver 400 R (i.e., an interface device situated atop a television receiver). Receiver 400 R includes a demodulator (demodulator/Forward Error Correction (FEC) decoder) 410 R to demodulate the signal and to decode the error correction data, an IR receiver 412 R for receiving IR remote control commands, a microprocessor 415 R, which operates interactively with demodulator/FEC unit 410 R, and a transport unit 420 R to transport the signal to an appropriate decoder 430 R within unit 400 R depending on the content of the signal, i.e., audio or video information. An NTSC Encoder 440 R encodes the decoded signal to a format suitable for use by signal processing circuits in a standard NTSC consumer VCR 402 and standard NTSC consumer television receiver 403 . Microprocessor (or microcontroller, or microcomputer) 415 R receives infrared (IR) control signals from remote control unit 450 R, and sends control information to VCR 402 via an IR link 418 R. Microprocessor 415 R also generates the on-screen display (OSD) signals needed for presenting the interactive sentence, or confirmation sentence, to the user. Microprocessor 415 R also receives and interprets cursor key X and Y information in order to control the highlighting of user choices in the on-screen displays. FIG. 5 shows a search request list which may be displayed as a screen display. In this embodiment of the invention, three actions are possible. First, as noted above, a show may be programmed to be recorded at its next airing without further intervention by the user. Second, as noted above, a reminder can be displayed on-screen that the desired program has been found. Third, a report listing various programs meeting the search criteria and airing in the immediate future (for example, the next three hours) can be prepared and displayed. In the example of FIG. 5 , the user has requested that he be reminded anytime an episode of Star Trek appears in the Program Guide. The user has also requested that the movie “The Shining” be recorded the next time it is found in the guide. The user has also requested that he be reminded anytime the word “robot” appears in the guide or in the program descriptions of the guide. These instructions will run until turned off by the user. The remaining search (i.e., movie, drama, now) is a request which indicates that the user wants to know which dramas are being aired in the immediate future (i.e., within the next three hours). The controller will prepare a report listing all dramatic movies on all channels which are being broadcast in the next few hours. After doing so, this entry will be automatically deleted. It is further envisioned that a user may review and edit or delete search terms in order to modify on-going searches. FIG. 6 shows a screen display of a “virtual keyboard” useful for entering search data. Four “Search Gophers” called “Watchdogs” are programmable for performing simultaneous searches of the Program Guide and auxiliary information data streams. By using the CURSOR and SELECT keys, a user can “press” one of the watchdog buttons on the left of the screen to select it. He may then use the alphabet keys to enter his search request. (While not explicitly shown, alphanumeric keys are also envisioned). When the user is satisfied with the text of his search request, he may press the Save key to save the search terms for this watchdog search process. If he makes an error, he may delete the error with the CLEAR key. The Gopher program is entered at step 700 of FIG. 7 . At step 705 , the search terms are retrieved. At step 710 , the Program Guide data is acquired. At step 715 a comparison is made to see if a match exists. If not the program is exited at step 720 . If a match does exist, then the user-entered instructions are retrieved. A check is made at step 725 to determine if a record instruction has been entered, if so the routine advances to step 730 at which the record commands are transmitted to the VCR either immediately or at an appropriate later time. The routine is then exited at step 735 . If however, a record instruction was not entered then the routine advances to step 740 at which a reminder message is generated for display, either immediately or at an appropriate later time as a “last minute reminder” before the desired show is broadcast, or both. The routine is then exited at step 735 . Although the invention was described with reference to a satellite television system, it is equally applicable to ground based television broadcast systems, both digital and analog.

In a television system in which at least program title information for programs which are to be transmitted in the future is transmitted in advance to form a channel guide listing, apparatus is provided for searching the listing for specific user-entered information, and upon successful conclusion to the search, the apparatus schedules the tuning of the desired program, or in the alternative, notifies the viewer of the availability of the program. In those instances where descriptive text accompanies the program listing, apparatus of the invention performs a search of the text for a particular text string which may relate to the title, the star, the director, or the context of the program, among other search criteria.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the fabrication of semiconductor integrated circuits and, in particular, to a self-aligned masking technique for use in ultra-high energy implants, i.e. implants of 1 MeV and greater. The technique has application to the formation of both localized buried implants and localized buried isolation structures. 2. Discussion of the Prior Art The technology of integrated circuits is based upon controlling electric charge in the surface region of a semiconductor material. Typically, the semiconductor material is crystalline silicon. Control of electric charge in the crystalline silicon lattice is achieved by introducing impurity or "dopant" atoms into selected regions of the lattice. The regions of the silicon lattice substrate to which dopant atoms are to be introduced are defined by transferring a corresponding pattern from a photographic "mask" to the substrate surface by a photolithographic, or "photomasking", process. In a typical sequence of steps in the photomasking process, a layer of silicon dioxide is first grown on the surface of the silicon substrate. A thin coating of photosensitive material, known as photoresist, is then formed on the oxide layer. The "negative" photoresist is then exposed to light through the mask. The portion of the photoresist not covered by opaque portions of the mask polymerize and harden as a result of this exposure (for a "positive" photoresist, the results would be the reverse). The unexposed portions are then washed away, leaving a photoresist pattern on the oxide surface that corresponds to the mask pattern. The portions of the silicon oxide that are not covered by the photoresist mask are then etched utilizing appropriate chemical procedures. The photoresist is then stripped, leaving an oxide layer that includes a desired pattern of "windows" through the oxide to the silicon surface. Dopant atoms are then introduced through the windows to the exposed silicon either by diffusion or by ion implantation. Dopant diffusion is performed by placing the silicon substrate in a furnace through which flows an inert gas that contains the desired dopant atoms, causing the dopant atoms to diffuse into the exposed regions of the silicon surface. In an ion implantation process, dopant atoms are introduced into the silicon by bombarding the exposed silicon regions with high-energy dopant ions. During the implantation process, the depth of penetration of the dopant ions into the silicon lattice is controlled by the ion implant energy, which is set by an accelerating field. The density of the implanted ions is controlled by the implant beam current. Typical commercial implant energy levels range from 30-200 kilo-electron-volts (KeV). Generally, a 1 micron layer of polysilicon, oxide or nitride is sufficient as a stopping material for these KeV implants. When implanted dopant ions penetrate the silicon surface, they damage the lattice by producing defects and dislocations, in effect amorphizing the crystalline silicon structure. These localized amorphized regions are recrystallized by annealing the silicon at temperatures on the order of 500°-600° C. subsequent to the ion implantation step. Recently, ultra-high energy implant machines that operate in the million-electron-volt (MeV) range have become commercially available. The ability to impart MeV range implant energies translates to the ability to create integrated circuit technologies that take advantage of the fact that dopant species can now be placed deeply into the silicon substrate at very high concentrations. However, full utilization of these ultra-high energy (i.e 1 MeV and greater) implants requires new techniques to create masks that can be used both as implant stoppers and to effectively pattern the silicon substrate target as desired. The approach to masking MeV implants into silicon, for example, differs in kind from KeV implants. Differences arise due to the fact that relatively massive quantities of structurally firm material must be used to adequately stop the ultrahigh energy dopant ions from reaching the substrate other than in the desired regions defined by the mask. Moreover, materials used for ultra-high energy masking should possess qualities that permit differential etching for creation of special purpose implant structures. SUMMARY OF THE INVENTION The present invention provides a self-aligned masking technique for ultra-high energy implants with application to localized buried implants and localized buried isolation structures. In a general masking procedure in accordance with the present invention, a sequence of alternating polysilicon and thin silicide layers is used to mask dopants over a wide range of MeV implant energies. The polysilicon and silicide layered structure terminates with a final polysilicon layer that is separated from the underlying silicon substrate by a layer of silicon oxide. The oxide layer is present, in part, to block secondary implantation from the masking materials due to interaction with the ultra-high energy dopant species. The ability to place dopant deep within a suitable semiconductor substrate can be exploited to form localized buried regions. Thus, the generalized masking process of the present invention, coupled with the ultra-high energy implants, can be used to create new types of integrated circuit structures based on localized buried implants and localized buried isolation structures. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description and accompanying drawings which set forth an illustrative embodiment in which the principles of the invention are utilized. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1E illustrate a general self-aligned masking procedure for use in ultra-high energy implants in accordance with the present invention. FIGS. 2A-2D illustrate application of the ultra-high energy self-aligned masking procedure to create localized deeply buried dopant regions. FIGS. 3A-3D illustrate application of ultra-high energy implants to create buried, localized isolation structures in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION Simulation of ultra-high energy ion implantation (i.e. ion implantation in the million-electron-volt (MeV) and greater range) through various stopping materials was used to explore appropriate implant stopping thicknesses. One set of simulations employed the Boltzmann transport model in SUPREM-3, while a second set used a three-dimensional Monte Carlo implant program, MARLOWE. Both SUPREM-3 and MARLOWE are well-known simulation programs. The results of these simulations showed that approximately 2 microns of tungsten is needed to effectively shield a 10 16 /cm 2 dose of silicon or phosphorous implanted at 2 MeV; a 25% increase in layer thickness to 2.5 microns permits polysilicon to be used. We have also found that a polysilicon layer having a thickness of about 1.0-1.25 microns per 1 Mev increment in implant energy is sufficient as a blocking layer for a silicon implant. Thus for a dopant species D having atomic weight W D , a polysilicon layer have the following thickness per 1 MeV increment in implant energy shold be sufficient as a block layer for the D dopant implant: ##EQU1## where W S is the atomic weight of silicon. As shown in FIG. 1A, a combination of alternating 2.0-2.5 micron polysilicon layers (10a,10b,10c) and thin titanium or tungsten silicide layers (12a,12b) can be used to mask dopants over a wide range of MeV implant energies. This layered approach is utilized to reduce strain problems that can occur if the thickness of a single polysilicon layer exceeds 2.5 microns and to provide a conductive silicide layer at convenient depths in the device structure. The polysilicon/silicide layering terminates with the bottom polysilicon layer 10c being separated from the substrate 14 by a silicon dioxide layer 16 greater than about 0.1 microns thick, preferably about 0.5 microns thick. The oxide layer 16 is present, in part, to block secondary implantation from the overlying masking materials due to interaction with the ultra-high energy dopant species and to provide a plasma etch stopper during patterning of the adjacent polysilicon layer, as described below. A detailed process suitable for masking 6 MEV silicon or phosphorous implants is illustrated schematically in FIGS. 1A-1E. The illustrated masking process begins with formation of the FIG. 1A structure described above. Consistent with our finding that a polysilicon thickness of about 1.0-1.25 microns is required for each 1 MeV increment in implant energy, the FIG. 1A structure utilizes three layers of polysilicon (10a,10b,10c), each about 2.0-2.5 microns thick, separated by silicide (tungsten or titanium) layers (12a,12b) about 0.05-0.3 microns, preferably about 0.2 microns, thick. Referring to FIG. 1B, the initial stage of a trench 11 for providing the window to the silicon substrate 14 is formed by first forming an oxide layer 18 on the upper polysilicon layer 10c. A photoresist layer 20 is then deposited on the upper oxide layer 18. The photoresist 20 is then patterned and etched to expose the oxide 18, which is then etched using hydrofluoric acid to expose the underlying polysilicon layer 10a. The exposed polysilicon 10a is then plasma etched to the underlying silicide layer 12a. Next, as shown in FIG. 1C, the overlying photoresist 20 is stripped and an oxidation step is performed to grow oxide 22 along the exposed polysilicon walls of the trench 11. A selectively etched oxide is then formed on the exposed silicide layer 12a and the oxidized silicide is selectively etched to expose the intermediate polysilicon layer 10b. The intermediate layer 10b of polysilicon is then plasma etched to expose the lower silicide layer 12b. Referring to FIG. 1D, an oxidation step is then performed to extend the oxide 22a along the walls of the trench 11 on the sidewalls of the intermediate polysilicon layer 10b. A selectively etched oxide is then formed from the silicide 10b and the lower layer 12b of silicide is selectively etched. The lower polysilicon layer 10c is then plasma etched to the oxide layer 16. Finally, as shown in FIG. 1E, the oxide, including both oxide layer 16 and the sidewall oxide in the trench 11, is stripped using hydrofluoric acid to expose a desired region 24 of the underlying FIGS. 2A-2D illustrate an application of the above-described general ultra-high energy self-aligned masking procedure to create localized deeply buried dopant regions. FIG. 2A shows a 2.0-2.5 micron polysilicon stopping layer 100 sandwiched between an overlying layer of thin oxide approximately 0.05 to 0.2 microns thick and a 0.2 to 0.5 micron oxide layer 104 formed on silicon substrate 106; the FIG. 2A structure is consistent with the polysilicon/oxide/substrate structure described above with respect to FIGS. 1A-1E. In the example to be described, the objective is to form a relatively deep, localized, buried (approximately 2 micron) high density n-type region utilizing a 2 MeV phosphorous implant. As described above, a Monte Carlo simulation has indicated that the 2.0-2.5 micron polysilicon layer 100 is sufficient to act as a stopper for a phosphorous implant at this energy. Referring to FIG. 2B, the first step in the process is to create an implant trench 108 in accordance with the generalized procedure described above. That is, a layer of photoresist 110 is first deposited on the upper oxide layer 102. The photoresist 110 is patterned to expose the underlying oxide 102 which is, in turn, etched with hydrofluoric acid to expose the underlying polysilicon 100. The polysilicon 100 is then plasma etched to the lower oxide layer 104. The oxide 104 is then etched to complete the trench 108 and expose a region 112 of the underlying silicon substrate 106. Next, referring to FIG. 2C, the photoresist 110 is stripped and the upper oxide 102 is removed in an HF dip. Phosphorous is then implanted into the exposed region 100 of the substrate 106 at a dose greater than 10 13 /cm 2 and at an implant energy of about 2 MeV. This results in the formation of a buried region 112 with its peak implant concentration approximately 2 microns deep. The peak implant concentration region 112 is also the region of the greatest lattice damage. Referring to FIG. 2D, the final step in the process is to recrystallize the damaged lattice region 112 to provide the desired n-type buried region in the silicon substrate 106. This is accomplished by first depositing resist over the entire exposed surface region 112 to protect the underlying silicon substrate 106. The resist is then patterned to expose the polysilicon 100, which is removed in a plasma etching step. Next, the resist is stripped from the region 112 and the oxide 104 is removed in an HF dip. Finally, the structure is exposed to a high temperature RTA or furnace anneal at 900° C. to effect the recrystallization of the damaged lattice region 112 to form the n-type buried region 114. In accordance with another aspect of the present invention, the generalized process described above with respect to FIGS. 1A-1E can be used to form buried isolation structures. It has been shown experimentally that extensive damage or complete amorphization takes place in the silicon lattice region where an ion implant peaks. However, this lattice damage is not distributed throughout the pathway of the energetic dopant. Thus, high energy MeV implants can be used to amorphize buried regions in silicon. If silicon is used as the amorphizing agent, then the substrate will not ultimately be altered. However, when silicon is used as the amorphizing agent, oxidation is enhanced only by a factor of 2, approximately, with respect to crystalline silicon. Using an n-type dopant species enhances the relative oxidation rate considerably. One embodiment of the envisioned procedure is schematically illustrated in FIGS. 3A-3D. FIG. 3A shows a crystalline silicon substrate 200. As shown in FIG. 3B, the first step in the construction of localized buried isolation structures is to deposit or grow a pad oxide layer 202 on the entire surface of the silicon substrate 200. Next, a 2 MeV implant of silicon or phosphorous is performed at a dose greater than 5×101 15 /cm 2 . This creates a region 204 of peak implant concentration and greatest lattice damage about 2 microns below the silicon surface. Next, a layer of resist 206 is deposited and patterned to exposed desired regions of the pad oxide 202. Next, referring to FIG. 3C, the structure is plasma etched to form trenches 208 to a depth below the region 204 of peak implant concentration. Next, the resist 206 is removed and a high pressure oxidation step is performed to form an oxide coating 210 on all exposed silicon areas and to convert the amorphized silicon regions 204 to isolation oxide 212. This results in isolated silicon regions 214 being formed in selected regions of the substrate 200. A high pressure oxidation is utilized to provide rapid distribution of oxygen to the amorphized regions of the lattice to increase the oxidation rate, since the natural tendency of the amorphized regions is toward recrystallization. As shown in FIG. 3D, a selective oxide etch produces the finalized localized buried isolation structures. In forming the isolation structures, the trenches 208 are suitably distributed to permit introduction of high pressure oxidation processes. The trenches 208 also offer an avenue for the relaxation of strain resulting from the oxidation of the buried amorphous layer. The FIG. 3A-3D example is directed to the formation of an amorphized region 204 (FIG. 3B) underlying the entire surface of the silicon substrate 200, i.e. wafer-wide. Those skilled in the art will appreciate that the masking procedure described above with respect to FIGS. 1A-1E can be utilized to create more localized isolation structures, as desired. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and apparatus within the scope of these claims and their equivalents be covered thereby.

A self-aligned masking process for use with ultra-high energy implants (implant energies equal to or greater than 1 MeV) is provided. The process can be applied to an arbitrary range of implant energies. Consequently, high doses of dopant may be implanted to give high concentrations that are deeply buried. This can be coupled with the fact that amorphization of the substrate lattice is relatively localized to the region where the ultra-high energy implant has peaked to yield a procedure to form buried, localized isolation structures.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] Embodiments of the present invention relate generally to processes for producing heavy oil. Various embodiments of the present invention are particularly useful in producing heavy oil emulsions that can be used in boilers in steam assisted gravity drainage (SAGD) processes for recovering heavy oil. [0003] 2. Description of the Related Art [0004] Heavy oil is naturally formed oil with very high viscosity but often contains impurities such as sulfur. While conventional light oil has viscosities ranging from about 0.5 centipoise (cP) to about 100 cP, heavy oil has a viscosity that ranges from 100 cP to over 1,000,000 cP. Heavy oil reserves are estimated to equal about fifteen percent of the total remaining oil resources in the world. In the United States alone, heavy oil resources are estimated at about 30.5 billion barrels and heavy oil production accounts for a substantial portion of domestic oil production. For example, in California alone, heavy oil production accounts for over sixty percent of the states total oil production. With reserves of conventional light oil becoming more difficult to find, improved methods of heavy oil extractions have become more important. Unfortunately, heavy oil is typically expensive to extract and recovery is much slower and less complete than for lighter oil reserves. Therefore, there is a compelling need to develop a more efficient and effective means for extracting heavy oil. [0005] Heavy oil that is too deep to be mined from the surface may be heated with hot fluids or steam to reduce the viscosity sufficiently for recovery by production wells. One thermal method, known as steam assisted gravity drainage (SAGD), provides for steam injection and oil production to be carried out through separate wells. The optimal configuration is an injector well which is substantially parallel to and situated above a producer well, which lies horizontally near the bottom of the formation. Thermal communication between the two wells is established by preheating the area between and around the injector well and producer well. Generally, such preheating is by steam circulation until the reservoir temperature between the injector and producer wellbore is at a temperature sufficient to drop the viscosity of the heavy oil so that it has sufficient mobility to flow to and be extracted through the producer well. Typically, preheating involves introducing steam through both the injector well and producer well. Steam circulation through the injector well and producer well will occur over a period of time. At some point before the circulation period ends, the temperature midway between the injector and producer will reach about 80 to 100° C. and the heavy oil will become movable (3000 cP or less). Once this occurs, the steam circulation rate for the producer well will be gradually reduced while the steam rate for the injector well will be maintained or increased. This imposes a pressure gradient from high, for the area around the injector well, to low, for the area around the producer well. With the oil viscosity low enough to move and the imposed pressure differential between the injection and production wellbores, steam (usually condensed to hot water) starts to flow from the injector into the producer. As the steam rate is continued to be adjusted downward in the producer well and upward in the injector well, the system arrives at steam assisted gravity drainage operation with no steam injection through the producer well and all the steam injection through the injector well. Once hydraulic communication is established between the pair of injector and producer wells, steam injection in the upper well and liquid production from the lower well can proceed. Due to gravity effects, the steam vapor tends to rise and develop a steam chamber at the top of the region being heated. The process is operated so that the liquid/vapor interface is maintained between the injector and producer wells to form a steam trap which prevents live steam from being produced through the producer well. [0006] Once the formation has been preheated, SAGD operation can commence. In operation of the SAGD process, steam will come into contact with the heavy oil in the formation and, thus, heat the heavy oil and increase its mobility by lessening its viscosity. Heated heavy oil will tend to flow downward by gravity and collect around the producer well. Heated heavy oil is produced through the producer well as it collects. Steam contacting the heavy oil will lose heat and tend to condense into water. The water will also tend to flow downward toward the producer well and is produced with the heavy oil. Such produced water may be treated to reduce impurities and reheated in the boiler for subsequent injection. [0007] Steam-based heavy oil recovery processes, such as SAGD processes described above, are most likely to burn natural gas as the fuel of choice to produce high-pressure steam for bitumen recovery. Steam requirements for such processes are on the order of two to five times as much steam as recovered oil. Thus, the cost of producing steam is one of the greatest operating expenses of recovery; the overall cost is greatly affected by the price of fuel used in producing steam. Thus, the use of natural gas as a fuel for producing steam reduces operating cost when the price of natural gas is low but these costs will increase proportionally as the price of natural gas increases. As a result, interest in alternative fuels is particularly kindled when the price of natural gas increases. SUMMARY [0008] In one embodiment of the present invention, there is provided a process for producing heavy oil from a subterranean region comprising withdrawing a heavy oil and water mixture from the subterranean region; separating at least a portion of the water from the heavy oil and water mixture to provide a first stream that contains the majority of the heavy oil from the heavy oil and water mixture and a second stream containing the portion of the water separated from the heavy oil and water mixture; emulsifying at least a portion of the first stream with a caustic and a surfactant and sufficient water, if any, from the second stream to produce an emulsified stream at the desired water content; introducing the emulsified stream as a fuel for a boiler to heat water and produce steam; and injecting the thus produced steam into the subterranean region. [0009] In another embodiment of the present invention, there is provided a process for producing heavy oil from a subterranean region comprising: withdrawing a heavy oil and water mixture from the subterranean region; heating the heavy oil and water mixture; separating at least a portion of the water from the heavy oil and water mixture to provide a first stream that contains a majority of the heavy oil from the heavy oil and water mixture and a second stream containing the portion of the water separated from the heavy oil and water mixture; introducing a water stream into a boiler; splitting the first stream into a third stream and a fourth stream; adding a caustic to the fourth stream and sufficient water, if any, from the second stream to produce an emulsion at the desired water content, and emulsifying the thus resulting mixture to produce an emulsified stream; introducing the emulsified stream as a fuel for the boiler to thus heat the water stream and to produce steam; and injecting the thus produced steam into the subterranean region. [0010] In still another embodiment of the present invention, there is provided the above processes where the water separated from the heavy oil and water mixture is heated in the boiler to produce steam and the steam is injected into the subterranean region to enhance heavy oil production. BRIEF DESCRIPTION OF THE DRAWING FIGURES [0011] Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein: [0012] FIG. 1 is a schematic illustration of a process in accordance with the current invention; [0013] FIG. 2 is a phase diagram illustrating the results for a caustic used as an emulsifying agent for heavy oil in water containing salt; [0014] FIG. 3 is a phase diagram illustrating the results for a surfactant used as an emulsifying agent for heavy oil in water containing salt; [0015] FIG. 4 is a phase diagram illustrating the results for a surfactant and a caustic used as emulsifying agents for heavy oil in water containing salt; [0016] FIG. 5 illustrates the stability of emulsified heavy oil in water where a caustic is the emulsifying agent both alone and with a surfactant. NOTATION AND NOMENCLATURE [0017] As used herein, the terms “a,” “an,” “the,” and “said” means one or more. [0018] As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. [0019] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up of the subject. [0020] As used herein, the terms “containing,” “contains,” and “contain” have the same open-ended meaning as “comprising,” “comprises,” and “comprise,” provided below. [0021] As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise,” provided above [0022] As used herein, the terms “including,” “includes,” and “include” have the same open-ended meaning as “comprising,” “comprises,” and “comprise,” provided above. [0023] As used herein, the term “heavy oil” means hydrocarbons having a viscosity from 100 cP to over 1,000,000 cP and generally includes bitumens, asphalts and tars. [0024] As used herein, the term “oil-in-water emulsion” refers to a mixture that has a water continuous phase that contains droplets of oil. [0025] As used herein, the term salt means primarily NaCl, but includes chlorides, carbonates, bicarbonates, bromides, sulfites, sulfates, and other anion species occurring in SAGD recycle water, along with any number of elemental cations, especially Na. [0026] As used herein, the term “steam” refers to H 2 O in a gaseous state. [0027] As used herein, the term “water” refers to H 2 O in a liquid state. [0028] As used herein, the term “water-in-oil emulsion” refers to a mixture that has an oil continuous phase that contains droplets of water. DETAILED DESCRIPTION [0029] The following detailed description of various embodiments of the invention references the accompanying drawings which illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. [0030] Turning now to FIG. 1 , an embodiment of a process in accordance with the current invention is illustrated. A heavy oil and water mixture are extracted from a hydrocarbon reservoir contained in a subterranean region (illustrated as Box 8 ). Preferably, the heavy oil and water mixture has a viscosity below 50 cp and more preferably to below 15 cp. Generally, this will bring the heavy oil temperature into the range of about 110° C. to 180° C. depending on its viscosity, hydrocarbon components and added diluent. If necessary, the heavy oil and water mixture may be heated to reduce its viscosity. [0031] The heavy oil and water mixture having a suitable viscosity, as described above, is transferred to separation vessel 16 through conduit 14 . Within separation vessel 16 , the heavy oil and water are allowed to separate in separation vessel 16 . Separation vessel 16 can be any suitable separation system for separating oil and water, such as a free water knock-out vessel for removal of free water followed by a treater vessel system comprising adding demulsifier chemicals, static or powered mixing and a treater vessel for a separation of water and oil. Separation vessel 16 will generally be about 130° C. at a pressure at least sufficient to keep the water phase liquid but may be 110° C. to 180° C. at a pressure at least sufficient to keep the water phase liquid. The water separated from the heavy oil is taken off through conduit 18 and the remaining heavy oil mixture is taken off through conduit 20 . The heavy oil and water mixture entering separation vessel 16 will generally have a water content of greater than 40% by volume and more typically will be about 60% to 85% water by volume, not including any added diluent. The heavy oil mixture exiting separation vessel 16 through conduit 20 will generally have a water content of 40% or less by volume and preferably the water content will be from 20% to 40% by volume in order to achieve a suitable oil-in-water emulsion. If the water content is too low, then water may be added as described below. [0032] The water exiting separation vessel 16 will contain impurities, most notably NaCl but others such as other salts, solids, silica and sand-related compounds and hydrocarbons. The water will generally be introduced by conduit 18 into a water treatment vessel 22 . Optionally, a slipstream 12 could be removed from conduit 18 and supply water to the heavy oil in conduit 32 or emulsification unit 38 if more water is needed for emulsifying the bitumen. While it is desirable to treat the water to remove impurities, especially the more corrosive ones it is an advantage of this invention that need to remove the salt will we reduced or even eliminated. While the current invention will operate with water having lower salt content, it is also operable with the water having salt content greater than 4000 ppm. This advantage is two fold. The need to treat water supplied through conduit 12 is reduced or eliminated because the emulsions produced according to the current process are resistant to deterious effects of salt. Additionally, the necessity of treatment for water entering boiler 28 is reduced because of its reintroduction downhole. [0033] Water coming from water treatment vessel 22 is introduced to boiler 28 through conduit 24 . Within boiler 28 , the water is heated to produce steam. The steam is then reintroduced to the hydrocarbon reservoir through conduit 30 for use in a SAGD type process. In addition to the water coming from water treatment vessel 22 , make up water can be introduced into conduit 24 and, hence, boiler 28 through conduit 26 . Optionally, instead of recycling water from water treatment vessel 22 to the boiler 28 , all the water for the boiler can be supplied through conduit 26 . However, this eliminates the benefit of recycling the water recovered from the reservoir. [0034] The heavy oil mixture in conduit 20 is further processed and transferred to a pipeline or another transportation media. A portion of the heavy oil mixture is separate off from conduit 20 into conduit 32 . Surfactants 34 and caustic 36 are introduced into the heavy oil mixture along with additional water from conduit 12 , if necessary, to achieve the desired emulsion water content, and the combined stream is introduced into emulsification unit 38 . Suitable emulsification units are known in the industry such as static mixers, pressure drop devices, powered mixers in pipes or vessels, and combinations of these techniques. Within the emulsification unit 38 , the combined stream is treated to emulsify the heavy oil in the water. It is important that the conditions be sufficient to create an emulsion that is substantially an oil-in-water emulsion rather than a water-in-oil emulsion or a mixture of oil-in-water emulsions and water-in-oil emulsions. As illustrated in the examples below, sufficient surfactant and caustic should be added to ensure an oil-in-water emulsion is created. [0035] It is an advantage of the current invention that the use of caustic increases the ability to form suitable emulsions in the presence of salt; thus, limiting the need to treat the heavy oil mixture or water to remove salt. Additionally, it has been found that the presence of group IIA ions, such as calcium and magnesium are undesirable and tend to make the emulsification more strongly favor the production of water-in-oil emulsions. Accordingly, the concentration of group IIA metal ions in the heavy oil stream going to emulsification unit 38 should be less than 250 ppm and more preferable less than 30 ppm. [0036] The heavy oil emulsion removed from emulsification unit 38 should have an average droplet size of less than 20 microns. It has been discovered that suitable droplet size can be achieved for emulsions using caustic only or caustic and surfactant. [0037] The heavy oil emulsion is removed from emulsification unit 38 through conduit 40 and introduce into boiler 28 . Within boiler 28 the heavy oil emulsion is burned as fuel to generate heat to heat water introduced into the boiler through conduit 24 . [0038] Suitable caustics for use in making the heavy oil emulsion include, but are not limited to, NaOH, KOH, and NH 4 OH. [0039] Suitable surfactants for us in making the heavy oil emulsions may be chosen from non-ionic, anionic, cationic, amphoteric surfactant and mixtures of one or more thereof. It is presently preferred to use non-ionic surfactants. In particular, it is preferred to use one or more non-ionic surfactants chosen from the following: [0040] Polyethylene glycol sorbitan monolaurate; Polyoxyethylenesorbitan monopalmitate; Polyethylene glycol sorbitan monostearate; polyoxyethylenesorbitan monooleate; Polyoxyethylenesorbitan trioleate; Octylphenoxypolyethoxyethanol; tert-Octylphenoxy Polyethyl Alcohol; Polyoxyethylene(30) octylphenyl ether; tert-Octylphenoxy Polyethyl Alcohol; Polyethylene glycol tert-octylphenylether; Polyethylene glycol tert-octylphenyl ether; Polyoxyethylene(23) lauryl ether; Polyethylene glycol hexadecyl ether; Polyethylene glycol oxtadecyl ether; Polyoxyetehylene(20) oleyl ether; jklPolyoxyethylene(100) stearyl ether; Polyoxyethylene (12) isooctylphenyl ether; Polyoxyethylene(40) nonylphenylether; and Polyoxyethylene(150) dinonylphenyl ether. EXAMPLES [0041] All of the emulsions in these examples were made in a Waring Blender Model 30-60. The blender was mounted in a stand along with a controller both made by Chandler Engineering. The rig in total was designated as a Chandler Model 3060-110V Mixer. The blender set-up uses open-top SS mixing cups with about 200-250 ml volume and a ‘chop’ style propeller in the bottom. [0042] Samples of bitumen were weighed into the mixing cups and placed in a temperature-controlled hot water bath, normally at 80° C. The surfactants and salt amounts were added to the pre-weighed water and mixed before addition on top of the bitumen in the mixing cup. A watch glass was placed over the mixing cup to minimize the evaporative water loss. The mixing cups were allowed to stand in the heating bath for 30 minutes before placing them in the Chandler Mixing Stand and spinning them, usually at 6000 rpm for 20 seconds. The emulsions were allowed to cool down for about 2 hours before making qualitative observations. Occasionally, microscope pictures were taken to verify the emulsion and the droplet size. Sometimes a particle size measurement was taken on a Malvert Instrument after the samples were diluted 100:1 with water. [0043] 1. Making Oil-in-Water Emulsions [0044] The following conditions were met for making the oil-in-water emulsion. [0000] Temperature: Sufficient for oil viscosity <1000 cp (80° C. was used for most of these bitumen runs) Mixer Speed: 3000 rpm minimum 6000 rpm normally using a 2.5″ ‘chop’ blade in 200 ml Waring Open-Top Mixing Cup Mixing Time: 5 seconds minimum, normally 20 seconds Water Content: 30 wt-% preferred for emulsion viscosity and stability, 20% minimum Surfactant: Caustic: 50-100% of the TAN titration value for up to 4,000 ppm NaCl water Non-ionic 2000-3000 ppm for up to at least surfactant: 10,000 ppm NaCl water Various combinations of caustic and non-ionic surfactant depending on saltwater. [0045] 2. Properties of the Oil-in-Water Emulsions [0046] Almost all of the emulsions made by the above technique had an average droplet size, or Dp50, of 6-10 microns with a Dp10 of 3-5 microns and a Dp90 of 15-35 microns. [0047] The viscosity of the oil-in-water emulsions is highly dependent on the water content of the emulsion, but with 30 wt-% water, an emulsion with a temperature in the range of 30° C. to 70° C. flows freely into a burner tip. A water content of 25% could be used if the emulsion temperature was about 40° C. to 80° C. Velocity ranges were dependent on obtaining temperatures high enough to sufficiently lower the viscosity without being so high that the emulsion would break down. [0048] The emulsions were stable for at least 3 weeks without breaking into two phases though some gentle stirring was necessary to re-mix a think layer of water on top of the emulsion. The average particle size over the 3 week period increased only by 1 micron (see FIG. 5 ) which indicated good stability for the short times necessary for on-site combustion in accordance with the current invention. Example 1 [0049] A bitumen sample having a Total Acid Number (TAN) of 2.6 (2.6 mg of KOH were required to neutralize the acid species in 1.0 g of the bitumen) was utilized. [0050] Emulsions were made utilizing various concentrations of salt in the water. The ability of the various caustics to make emulsions in the presence of salt was tested. The caustics tested were NaOH, KOH, and NH 4 OH. [0051] A phase diagram illustrating the results for NaOH is shown in FIG. 2 . As illustrated in the diagram NaOH can make emulsions up to approximately 4000 ppm salt in water. [0052] KOH was similarly tested and the results indicated that KOH could make oil-in-water emulsions up to 5500 ppm salt in water. [0053] NH 4 OH was similarly tested and the results illustrated that NH 4 OH made oil-in-water emulsions with pure water but did not make them with 4000 ppm salt water. Example 2 [0054] Various commercial surfactants were tested utilizing various concentrations of salt in the water. Emulsions were made with and without caustics. The results indicated that the presence of the caustic did not lower the amount of surfactant necessary to make an oil-in-water emulsion but that the caustic made the emulsion more stable and less likely to separate into two phases over time. [0055] Exemplary results can be seen in FIGS. 3 , 4 and 5 which show the results for the surfactant polyethylene glycol sorbitan monolaurate (PGSM). FIG. 3 is a phase diagram for emulsions made using PGSM and no caustic versus various concentrations of salt. FIG. 4 is a similar phase diagram for emulsions made using PGSM and caustic. FIG. 5 illustrates the stability of emulsions made with PGSM and caustic and with caustic alone. The emulsions in FIG. 5 were prepared from 0.06 g NaOH in 100 g total solution (70 g heavy oil and 30 g water) and contained 3000 ppm PGSM. The amount of caustic added equated to 46% of the heavy oil's TAN value. [0056] The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention. [0057] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

A process for emulsifying and burning a portion of heavy oil extracted from an underground reservoir is disclosed, wherein the emulsified heavy oil is burned to generate steam and a caustic is used to aid in emulsifying the heavy oil.

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a 35 U.S.C. §371 National Phase conversion of PCT/FR2005/000596 filed March 11, 2005, which claims priority of French Application No. 0402554 filed Mar. 11, 2004. The PCT International Application was published in the French language. FIELD OF THE INVENTION The present invention relates to saccharide derivatives of genkwanin and sakuranetin. More specifically, it relates to (i) the cosmetic or dermatological use, on the one hand, and the therapeutic use, on the other hand, of saccharide derivatives of genkwanin and sakuranetin of formula I below, (ii) novel derivatives of formula I as industrial products, and (iii) the manufacturing process therefor. The compounds according to the invention correspond to formula I: in which, the symbol represents a single or double bond, R represents H or a saccharide residue, especially of structure S 1 or S 2 : Z represents H or a C 1 -C 4 alkyl, C 1 -C 5 acyl, saccharide or sulfate group. BACKGROUND OF THE INVENTION It is known that a number of products of formula I have already been described and studied in the past. In particular, 5-O-β-D-primeverosyl-genkwanin (which is a compound of formula I in which the symbol represents a double bond, R is a saccharide residue of structure S 2 and Z is H) is obtained by extraction of Gnidia kraussiana (a plant from the African savanna of the Thymeleacea family) and has immune (especially immunostimulatory), anticancer and antileukemic properties. More specifically, during serious immune disorders, the physiological lymphoblasts are in hyperplasia, and the value of 5-O-β-D-primeverosyl-genkwanin lies in the fact that it destroys the lymphoblasts formed. See in this respect FR 2 510 580 A, FR 2 597 751 A and the article by Jer-Huei LIN et al., Yaowu Shipin Fenxi, 2001; 9(1), 6-11. Pinostrobin-5-glucoside (which is a compound of formula I in which the symbol represents a double bond, R is H and Z is H) was isolated from the bark of Prunus cerasus and is considered as being characteristic of the species Prunus cerasus . See in this respect the article by Martin Geibel et al., Phythochemistry, 1991; 30(5), 1519-1521. Sakuranin, other nomenclature: sakuranetin-5-glucoside (which is a compound of formula I in which the symbol represents a single bond, R is H and Z is H) was isolated from Prunus yedoensis , without its possible cosmetic or pharmacological properties (especially the free-radical-scavenging properties) being studied. See in this respect the publication Merck Index, 12th Edition, 1996 , Monograph No. 8470, pages 1431-1432. The abovementioned prior art does not describe or suggest that the compounds of formula I according to the invention have beneficial properties: in cosmetics or dermatopharmaceutics, as substances for improving the texture of the skin, and in human or veterinary therapy (especially warm-blooded animals), as free-radical scavengers. SUMMARY OF THE INVENTION According to a first aspect of the invention, a novel use of saccharide derivatives of genkwanin and sakuranetin is recommended, as (a) cosmetic or dermatological substances, or (b) free-radical-scavenging substances, for (a) improving the texture of the skin or, respectively, (b) treating or preventing disorders caused by free radicals. In this regard, a novel use (a) in cosmetics or dermatology, on the one hand, or (b) in human or veterinary therapy, on the other hand, is provided, said use being characterized in that use is made of a substance chosen from the group consisting of (i) saccharide derivatives of genkwanin or sakuranetin of formula I: in which: the symbol represents a single or double bond, R represents H or a saccharide residue, especially of structure S 1 or S 2 : Z represents H or a C 1 -C 4 alkyl, C 1 -C 5 acyl, saccharide or sulfate group, and (ii) mixtures thereof, as (a) a cosmetic or dermatological active ingredient or, respectively, (b) a free-radical-scavenging active ingredient, for obtaining (a) a cosmetic or dermatological preparation for improving the texture of the skin or, respectively, (b) a medicament for therapeutic use against disorders caused by free radicals. According to a second aspect of the invention, compounds of formula I in which R is especially a saccharide residue of structure S 1 , and mixtures thereof, are recommended as novel industrial products. According to a third aspect of the invention, a process for preparing compounds of formula I and in particular for the preparation of said novel compounds is recommended. BRIEF DESCRIPTION OF THE DRAWINGS The attached figures concern some of the results of the tests undertaken with products of formula I: FIG. 1 shows that the products of formula I tested have free-radical-scavenging properties, and FIGS. 2 and 3 show that the products of formula I tested are of value as immunosuppressants. DETAILED DESCRIPTION OF THE INVENTION The present invention covers saccharide derivatives of genkwanin when the symbol represents a double bond, on the one hand, and saccharide derivatives of sakuranetin when said symbol represents a single bond, on the other hand. In the definition of Z, the C 1 -C 4 alkyl groups comprise linear or branched groups with a hydrocarbon-based chain, i.e. methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl groups; the C 1 -C 5 acyl groups comprise linear or branched aliphatic groups with a hydrocarbon-based chain, containing from 1 to 5 carbon atoms, i.e. CH 3 CO, CH 3 CH 2 CO, CH 3 CH 2 CH 2 CO, (CH 3 ) 2 CHCO, CH 3 CH 2 CH 2 CH 2 CO, (CH 3 ) 2 CHCH 2 CO, CH 3 CH 2 CH(CH 3 ) CO and (CH 3 ) 3 CCO groups; the sulfate group comprises the residue SO 3 − , which is mainly encountered in the acid form SO 3 H and, where appropriate, in a salified form such as SO 3 NH 4 or SO 3 Na. Finally, the group Z may represent a saccharide residue, especially a glucosyl, xylosyl, thioxylosyl, fructosyl, mannosyl, etc. residue. The saccharide group included in the definition of R may be any saccharide residue, especially one of the residues listed above for the group for Z. Advantageously, the groups R according to the invention will be of structure S 1 or S 2 , the structure S 1 being preferred. Among the compounds of formula I in accordance with the invention, mention may be made advantageously of: 5-[O-6-(D-glucopyranosyl)-β-D-glucopyranosyl]oxy-2-(4-ethoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one [other nomenclature: 4′-ethoxy-genkwanin-5-(D-glucosido)-β-D-glucoside] of formula Ia: which is the most advantageous product of the invention; the abovementioned 5-O-β-D-primeverosyl-genkwanin of formula IIa: the abovementioned pinostrobin-5-glucoside of formula IIIa: 2,3-dihydro-5-[O-6-(D-gluocpyranosyl)-β-D-glucopyranosyl]oxy-2-(4-ethoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one [other nomenclature: 4′-ethoxysakuranetin-5-(D-glucoside)-β-D-glucoside of formula Ib: which is the homolog of the product of formula Ia with regard to the replacement of genkwanin with sakuranetin, 5-O-β-D-primeverosyl-sakuranetin of formula IIb: and derivatives thereof in which Z is a sulfate group (preferably SO 3 H or, where appropriate, SO 3 Na or even SO 3 NH 4 ). Among the novel compounds according to the invention, mention may be made more particularly of the products of formula IV: in which the symbol represents a single or double bond and Z 1 has the same definition as Z above and advantageously represents a C 1 -C 4 alkyl group (preferably an ethyl group) or a sulfate group (preferably an SO 3 H group). The compounds of formula I may be prepared according to a method that is known per se by application of standard reaction mechanisms and/or extraction processes. By way of example: (i) genkwanin, sakuranetin or a saccharide thereof are extracted from a suitable plant belonging to the set: Prunus, Gnidia and Daphne ; (ii) the aglycone is osylated in position 5 with a suitable saccharide (if necessary after blocking the OH function in position 4′ if it is not protected); and/or (iii) the 4′—OH group of the saccharide extracted or prepared as indicated above (if necessary after deprotection of the 4′—OH group) is etherified (especially using an alkyl iodide so as not to affect the OH groups of the sugar portion), esterified or sulfated. The process that is recommended according to the invention for preparing the compound of formula Ia is characterized in that it comprises the steps consisting in: (1°) extracting the ground roots of Daphne gnidium with CH 2 Cl 2 ; (2°) filtering to discard the methylene chloride solution thus obtained, and collecting the solid residue, which is dried; (3°) extracting said dry solid residue thus obtained with CH 3 OH; (4°) filtering to collect the methanol solution thus obtained, and discarding the resulting solid residue; (5°) evaporating to dryness the methanol solution thus collected, under vacuum, at a temperature of less than or equal to 60° C., to obtain a solid residue; (6°) washing the solid residue thus obtained in step (5°), with water at a temperature of less than or equal to 60° C. with stirring, and leaving to cool; (7°) removing the washing water and then taking up the solid residue with CH 3 OH; (8°) repeating the cycle of operations of steps (5°) to (7°) 3 to 7 times until the final washing water is pale yellow and clear; (9°) taking up the resulting dry residue in a 25/2 w/w methanol/water mixture in an amount that is suitable to obtain a liquid with a density of 0.885 g/mL; (10°) leaving said liquid to stand at 2-4° C. and preferably at 3° C., for at least 2 days and preferably for 3 days, and collecting the precipitate formed; (11°) washing said precipitate successively with methanol and then methanol/ether mixtures with increasing ether contents, until the supernatant is colorless; (12°) filtering off the precipitate thus obtained, and washing it several times with ether, until the washing ether is colorless; (13°) filtering off and drying the resulting solid product, which consists of a mixture of the products of formulae Ia, IIa and IIIa; and (14°) if necessary, separating said mixture to collect the product of formula Ia. In practice, the extraction step (1°) is performed under warm conditions (i.e. at a temperature of 30-35° C. at atmospheric pressure (˜10 5 Pa) or, where appropriate, at a higher temperature under reduced pressure) for 3-6 days (preferably for 5 days) in apparatus of Kumagawa type; the extraction in step (3°) is performed under warm conditions (especially at a temperature of 45-55° C. at normal pressure (≈10 5 Pa) or, where appropriate, at a higher temperature under reduced pressure) in the same apparatus for 3-6 days (preferably for 5 days). As regards the abovementioned preferential modes, a mixture Ia/IIa/IIIa in a weight ratio of about 10/85/5 w/w is obtained after step (13°). As a function of the purifications undertaken by chromatography, the following is obtained after step (14°): a mixture Ia/IIa enriched in Ia, especially an 80/20 w/w Ia/IIa mixture, or the essentially pure compound of formula Ia (i.e. in a purity of greater than or equal to 98%) or the more purified compound of formula Ia (i.e. in a purity of greater than or equal to 99.5%). The compounds of formula I, and in particular the novel compounds of formula IV, are useful in cosmetics or dermopharmaceutics as agents for improving the texture of the skin. When administered topically, in the form of a solution, a lotion, a gel or an emulsion, which may be a multiple emulsion (for example an O/L/O or L/O/L emulsion), the compounds of formula I or IV have: a favorable action on the effects of ageing of the skin, especially for reducing wrinkles and giving the skin the desired firmness and suppleness; an anti-ageing effect that allows the injection of collagen to be avoided; and power in controlling the moisturization of the skin. In particular, since the compounds of formula I or, respectively, IV become readily hydrated to I.xH 2 O or, respectively, IV.xH 2 O (in which x is an integer or fraction especially between 0.3 and 5), they serve, according to the invention, in the thickness of the skin as moisturization regulators, either by taking up the excess water, or especially by providing water when the water content in the skin is insufficient. Besides the abovementioned cosmetic or dermatological aspect, the compounds of formula I or IV are useful in human or veterinary therapy on account of their free-radical-scavenging properties, for treating and especially preventing disorders induced by free radicals. Said disorders in particular include pathologies induced by an overproduction or uncontrolled production of free radicals in the body, such as myelodegenerative diseases, manic-depressive syndrome and senile dementia. The compounds of formula I or IV are above all advantageous in human therapy before these pathologies become irreversible. Moreover, all the compounds of formula IV that were tested with regard to their immunomodulatory, antiatheroma and anticancer properties proved to be effective. The preferred substance according to the invention, which consists of the product of formula Ia or the abovementioned mixtures Ia/IIa/IIIa (i.e. extract of Daphne gnidium ) and Ia/IIa, is particularly active against certain acute cancers and leukemias (antiblastic effect, i.e. destruction of leukoblasts) and chronic myeloid leukemia. According to the invention, a cosmetic (a), dermatopharmaceutical (b) or therapeutic (c) composition is recommended, which is characterized in that: (a) the cosmetic composition contains, in combination with a physiologically acceptable topical excipient, at least one compound of formula I; (b) the dermatopharmaceutical composition contains, in combination with a physiologically acceptable and especially topical excipient, at least one compound of formula I; or (c) the therapeutic composition contains, in combination with a physiologically acceptable and especially oral or injectable excipient, at least one compound of formula IV as immunomodulatory active ingredient, especially against recent bouts of multiple sclerosis, or an anticancer active ingredient, especially against chronic myeloid leukemia. Other advantages and characteristics of the invention will be understood more clearly on reading the preparation examples and the results of cosmetological and pharmacological tests below. Needless to say, these data are in no way limiting, but provided for the purpose of illustration. EXAMPLES The following examples are provided only for the purpose of illustrating the invention and are not to be construed as limiting the invention in any manner. A few typical compounds of formula I have been collated in table I below with comparative products (CP.1 and CP.2). TABLE I Typical compounds according to the invention Example Structure Ex. 1 10/85/5 w/w Ia/IIa/IIIa mixture Ex. 2 Product of formula IIa Ex. 3 Product of formula IIIa Ex. 4 80/20 w/w Ia/IIa mixture Ex. 5 Product of formula Ib Ex. 6 Product of formula IIb Ex. 7 4′-sulfate of the product of formula Ib Ex. 8 Product of formula Ia Ex. 9 4′-sulfate of the product of formula Ia Ex. 10 10/85/5 w/w Ib/IIa/IIIa mixture CP. 1 Genkwanin CP. 2 Sakuranetin Preparation A -Production of the 10/85/5 w/w Ia/IIa/IIIa Mixture (Ex. 1)- 11 kg of Daphne gnidium roots (plant from the Mediterranean basin of the Thymeleacea family) are ground and then treated continuously with methylene chloride, at 30-35° C., for 5 days in apparatus of Kumagawa type. The liquid solution thus obtained is discarded and the solid residue is collected and dried. Said residue thus dried is extracted with hot methanol (45-55° C.) for 5 days in said apparatus of Kumagawa type. The methanolic extract, obtained after discarding the solid residue, is treated in the following manner: evaporation to dryness under reduced pressure at a temperature below 60° C. in a round-bottomed flask; washing of the solid residue thus obtained with hot water while shaking so as to detach said residue from the bottom of the flask; cooling to room temperature and removal of the washing water; and uptake of the residue in methanol. This succession of treatments is repeated 5 to 7 times, depending on the origin of the roots, until the final washing water is clear and pale yellow. The resulting residue is taken up in warm methanol (45-55° C.) containing 8% by weight of water, in an amount sufficient to obtain a liquid with a density of 0.885 g/mL. The resulting solution is left to stand for 3 days at 3° C. and the precipitate formed is then recovered by centrifugation. This precipitate is washed with successive fractions of methanol and then of methanol/dimethyl ether (or methanol/diethyl ether) mixtures increasingly rich in ether. When the supernatant is finally virtually colorless, the precipitate is filtered off and washed several times with ether until the washing ether is colorless. A very pale beige-colored solid is obtained, and is dried under reduced pressure and then ground. This solid is a Ia/IIa/IIIa mixture in a 10/85/5 weight ratio. The yield is about 2 to 3% depending on the origin of the plant and the season during which the roots were harvested. Analysis Since the compounds of formulae Ia, IIa and IIIa are of similar structure (flavonoid part and saccharide part), they have strong spectroscopic similarities, in particular in the ultraviolet and infrared regions. UV spectrum (in 80/20 v/v acetonitrile/water mixture) Two absorption bands at 331.7 and 261.7 nanometers are observed (the band at 261.7 nm having an intensity that is about half that of the band at 331.7 nm). IR spectra (in KBr disk) The following bands are observed: strong band at 3374 cm −1 (O—H of the sugar part); strong band at 1635 cm −1 (vibration band of the flavone carbonyl); medium-strength band at 1609 cm −1 (vibration band of the flavone ethylenic double bond); and medium-strength bands at 1450 and 1360 cm −1 (vibration bands of the aromatic parts). Preparation B -Production of the 80/20 w/w Ia/IIa Mixture (Ex. 4)- By subjecting the product of example 1 to separative chromatography (HPLC), the 80/20 w/w Ia/IIa mixture is obtained. Preparation C -Production of the Product of Formula Ia (Ex. 8)- By subjecting the product of example 1 or of example 4 to a more rigorous separative chromatography, the compound of formula Ia is obtained in a purity of greater than or equal to 98%, or even in a purity of greater than or equal to 99.5%. Analysis The NMR spectra (at 250 Mhz as a solution in deuterated methanol) and the mass spectrum (via the FAB technique) were determined. The results obtained are as follows, in which the first sugar unit is that attached to the flavone backbone and the 2nd sugar unit is that of structure S 1 or S 2 . NMR Spectrum triplet centered at 1.31 ppm (methyl group CH 3 of the alkylenated phenyl chain); quadrate centered at 3.20 ppm (methanol group CH 2 of said alkyl chain); unresolved band from 3.27 to 4.39 ppm (protons of the two sugar units) [detailed assignments on the basis of COSY, HMQC and HMBC experiments at 600 Mhz, the two anomeric protons of the two sugar units of which, at, respectively, 4.75 ppm (doublet) for the 1st unit attached to the flavone at position 5, and 4.27 ppm (doublet) for the 2nd unit; —CH 2 —O— bridge between the two sugar units at 3.60 (d) and 3.93 (d) ppm; and —CH 2 — at 5 on the 2nd sugar unit at 3.32 (d) and 3.60 (d) ppm; the stereochemistry of the two sugar units having been established on the basis of vicinal proton-proton couplings starting from the anomeric protons]; 3.87 ppm (CH 3 of the CH 3 —O— group); 6.60 ppm (ethylenic proton of the flavone part); unresolved band at 6.91-6.94 ppm (4 aromatic protons); and unresolved band at 7.82-7.86 ppm (2 aromatic protons). Mass Spectrum Molecular mass: 636.598 (C 30 H 36 O 15 ) Mass peak: 636; Na and K adducts in compliance. The mass spectrometry method was also used to confirm the structures of formulae Ia, IIa and IIIa after acetylation of all the O—H groups (with acetic anhydride/pyridine mixture); the acetylation products were analyzed by mass spectrometry after chromatographic purification on silica (eluent: 50/50 v/v water/acetonitrile). Preparation C a -Production of the Products of Formula IIa (Ex. 2) and of Formula IIIa (Ex. 3)- By subjecting the product of example 1 to more rigorous separative chromatographies, the products of formula IIa (Ex. 2) and of formula IIIa (Ex. 3) were isolated in a purity of greater than or equal to 98%. Analysis (Performed as Indicated in Preparation C Above) NMR spectrum of Ex. 2 The NMR spectrum of the product of formula IIa (Ex. 2) is identical to that of the product of formula Ia (Ex. 8), but with the following differences: absence of CH 3 signal at 1 . 31 ppm and of CH 2 signal at 3 . 20 ppm for the ethyl chain; disappearance of the signals at 3.32 and 3.60 ppm for the CH 2 in position 5 on the second sugar. Mass spectrum of Ex. 2 Molecular mass: 578 . 519 (C 27 H 30 O 14 ) Mass peak: 578; Na and K adducts in compliance. NMR spectrum of Ex. 3 The NMR spectrum of the product of formula IIIa (Ex. 3) is identical to that of the product of formula Ia (Ex. 8), but with the following difference: simplification of the unresolved band corresponding to the protons of the sugar part, with only one anomeric proton at 4.76 ppm (d). Mass spectrum of Ex. 3 Molecular mass: 446.404 (C 22 H 22 O 10 ) Mass peak: 446; Na and K adducts in compliance. Preparation D -Production of the Product of Formula Ib (Ex. 5)- By repeating the process of Preparations A and C above, starting with the bark or roots of Prunus yedoensis , the compound of formula Ib is obtained. Preparation E -Production of the 4′-Sulfate of the Product of Formula Ib (Ex. 7)- The expected product is obtained by sulfatation of the 4′—OH group according to a method that is known per se. Tests F The capacity for improving the texture of the skin was evaluated by means of regenerating skin tissue after burning. A portion of the back of adult male rats is shaved and a 0.5 cm 2 metal plate heated to a temperature of 130° C. is applied to this portion to create a calibrated burn area. A gel containing 0 (control batch) or 1.5% by weight of product of formula I (treated batches) is applied once a day for 21 days to the rats' burn (8 animals per test product, 10 animals for the control batch). It is found that, in the treated batches (Ex. 1 to Ex. 10), regeneration of the skin tissue is obtained in 1 month; on the other hand, in the control batch, said regeneration takes place in 6 to 8 weeks. Tests G The free-radical-scavenging properties of the products according to the invention (Ex. 1 to Ex. 10) were studied according to the “determination of the free-radical defense potential”) process, which is the subject of French patent application No. 03 12 351 filed on 22 Oct. 2003, by monitoring the kinetics of erythrocyte lysis (especially of sheep erythrocytes; it is also possible to work on whole blood or blood plasma) induced by free radicals generated in situ, in the presence of a product according to the invention at doses increasing from 0 mg/L (control batch) to 100 mg/L (treated batches), and with hydrolysis of the reaction medium using a mixture of enzymes (β-glucosidase, sulfatase and β-glucuronidase). According to this process, the (T½) time, which corresponds to the lysis of half of the cells under consideration, in this case erythrocytes, as a function of the concentration (in mg/L) of the test product of formula I, is measured in particular. Part of the results obtained are collated in FIG. 1 below, in which curve 1 is that for the product Ex. 1; curve 2 that for Ex. 2; curve 3, that for Ex. 3; and curve 4, that for Ex. 4. FIG. 1 shows that Ex. 4 (i.e. the 80/20 w/w Ia/IIa mixture), which contains compound Ia (i.e. Ex. 8) “contaminated” with compound IIa (i.e. Ex. 2), is more active as a free-radical-scavenging substance than Ex. 1, Ex. 2 and Ex. 3. Tests H Additional tests were performed with Ex. 10 and the constituents thereof (Ex. 5, Ex. 2 and Ex. 3) on human blood cells [supplied by EFS (Etablissements Francais du Sang)]. These are blood cells isolated on a Ficoll cushion and stored under liquid nitrogen vapor. After thawing, said cells are incubated for 24 hours at 37° C. before addition of the test products of formula I. After reincubation at 37° C. for 24 hours or 48 hours, the cells are analyzed to assess any expression of significant membrane markers, according to table II below. TABLE II Analyses of the cell Expression of the membrane material marker T lymphocytes CD3 Cytotoxic T lymphocytes CD8 “Helper” T lymphocytes CD4 B lymphocytes CD19 Monocytes/macrophages CD11c Cell activations CD69 Cell supernatants IL-2 As indicated in table II, the cell supernatants were analyzed for their interleukin 2 (IL-2) content, which is a product that induces T lymphocyte proliferation, with or without addition of an activator, especially (i) phytohematoglutinine (PHA), which is a standard activator, and (ii) a superantigen (SEB), which induces an interaction between class II B lymphocyte molecules with T lymphocyte receptors or TRC, thus mimicking an antigen presentation. Two major points are observed, namely: (1) Ex. 10 and its constituents, Ex. 5, Ex. 2 and Ex. 3 do not induce proliferation of the blood cells of the immune response; and (2) Ex. 10, Ex. 5, Ex. 2 and Ex. 3 are active on these cells and interfere with the cascades of signals leading to an immune response; the effect observed appears to be immunosuppressant with a decrease in antibody production for the B lymphocytes, a decrease in class II MHCs for dendritic cells and an inhibition of IL-2 production (factor inducing lymphocyte proliferation) following stimulation with PHA or SEB. FIGS. 2 and 3 show the effect of products Ex. 10, Ex. 5, Ex. 2 and Ex. 3 on the PHA-induced ( FIG. 2 ) and, respectively, SEB-induced ( FIG. 3 ) secretion of IL-2. In particular, FIG. 3 , on the one hand, shows the production (expressed in pg/mL) of IL-2 relative to the concentration (expressed in pmol/mL) of SEB (curve 11), SEB+Ex. 10 (curve 12), SEB+Ex. 5 (curve 13), SEB+Ex. 2 (curve 14) and SEB+Ex. 3 (curve 15) and, on the other hand, shows the effect of products Ex. 10, Ex. 5, Ex. 2 and Ex. 3 on immune cell stimulation. In conclusion, the compounds of formula IV, and especially the products of examples 1, 4, 8, 9 and 10, are particularly advantageous with regard to: their immunomodulatory effects, especially with respect to recent bouts of multiple sclerosis; their immunosuppressant effects, especially illustrated by inhibition of the activity of the stimulants PHA and SEB on IL-2 production; their antiblastic effects (i.e. by destruction of leukoblasts) and which are useful in the treatment of chronic myeloid leukemia and acute leukemias; their effects against certain cancers; and the virtual absence of harmful side effects when they are administered topically, orally or by injection. In human adults, the recommended dosage for the products of formula I, and preferably the products of formula IV, is about 50 mg/kg per os. These products may also be administered locally in the form of gels or pomades; ointments or lotions; in this event, the local form may contain from 1% to 5% by weight of product of formula I, of formula IV or of a mixture thereof, relative to the weight of said local form.

The invention relates to: (i) the use of osyl derivatives of genkwanin and sakuranetin having formula (I) in (a) cosmetics or dermatology and (b) therapeutics; (ii) the use of novel derivatives having formula (I) as industrial products; and (iii) the production method thereof [Formula (I)], wherein symbol [Formula (II)] represents a single or double bond, R represents H or an osyl residue, particularly with structure S 1 or s 2 [Formula (III)], Z represents H, an alkyl group at C 1 -C 4 , acyl at C 1 -C 5 , monosaccharide or sulphate.

FIELD The present disclosure relates generally to the field of video decoding and, more specifically, to techniques for optimizing the Context-based Adaptive Binary Arithmetic Coding (CABAC) for the H.264 video decoding. BACKGROUND To support the H.264 main profile, the Context-based Adaptive Binary Arithmetic Coding (CABAC) is a technical challenge. The basic idea of the binary arithmetic coding process is recursive interval division. The arithmetic decoding engine core keeps two registers. The first register is a range register with 9-bits. The second register is an offset register which is 9-bits in a regular mode and 10-bits in a bypass mode. The range register keeps track of the width of the current interval. The offset is from the bit-stream and points to the current location within the range. When decoding a bin, the range is divided into two subintervals depending on the context to decode that specific bin. After the bin is decided, the range and offset are updated. After decoding one bin, range and offset will be renormalized to keep the precision to decode next bin. It ensures the most significant bit of the 9 bit register range is always 1. Thus, there are a great number of bit wise operations in the CABAC core, frequent renormalization and bitwise reading from a bit-stream, all of which are computationally costly. There is therefore a continuing need for techniques for optimizing the Context-based Adaptive Binary Arithmetic Coding (CABAC) for the H.264 video decoding. SUMMARY Techniques for optimizing the Context-based Adaptive Binary Arithmetic Coding (CABAC) for the H.264 video decoding. In one configuration, a device comprising a processing circuit operative to implement a set of instructions to decode multiple bins simultaneously and renormalize an offset register and a range register, after the multiple bins are decoded is provided. The device also includes a memory coupled to the processing circuit. In another aspect, an integrated circuit is provided comprising a processing circuit operative to implement a set of instructions to decode multiple bins simultaneously and renormalize an offset register and a range register, after the multiple bins are decoded. The integrated circuit also includes a memory coupled to the processing circuit. In a still further aspect, a computer program product is provided including a computer readable medium having instructions for causing a computer to: decode multiple bins simultaneously. The computer program product also includes instructions to renormalize for multi-bit aligning an offset register and a range register, after the multiple bins are decoded. Additional aspects will become more readily apparent from the detailed description, particularly when taken together with the appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS Aspects and configurations of the disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify corresponding elements throughout. FIG. 1 shows a general block diagram of a wireless device. FIG. 2A shows an exemplary H.264 standard range register. FIG. 2B shows an exemplary H.264 standard offset register. FIG. 2C shows an exemplary H.264 standard MPS case. FIG. 2D shows an exemplary H.264 standard LPS case. FIG. 3 shows a sample (psuedocode) instruction set of a H.264 standard arithmetic decoding process for one bin. FIG. 4 shows a flowchart of a H.264 standard renormalization process. FIG. 5 shows a flowchart of a H.264 standard normal decoding mode process. FIG. 6 shows a flowchart of a H.264 standard bypass decoding mode process. FIG. 7 shows a flowchart of a H.264 standard terminate decoding process. FIGS. 8A and 8B show a modified range register and an offset register. FIG. 8C shows a block diagram of a video processor using the modified range register and an offset register of FIGS. 8A and 8B . FIG. 9 shows a flowchart of a normal decoding mode process. FIG. 10A shows a flowchart of a first renormalization process. FIG. 10B shows a flowchart of a second renormalization process. FIG. 10C shows a flowchart of a third renormalization process. FIG. 11 shows a flowchart of a bypass decoding mode process. FIG. 12 shows a flowchart of a terminate decoding process. FIG. 13A shows a sample (psuedocode) instruction set for a prefix EG code decoding process. FIG. 13B shows a range and offset relationship diagram the prefix EG code decoding process of FIG. 13A . FIG. 14A shows a sample (psuedocode) instruction set for a suffix EG code decoding process. FIG. 14B shows a range and offset relationship diagram the suffix EG code decoding process of FIG. 14A . FIG. 15A shows a flowchart of a prefix EGK code decoding process. FIG. 15B shows a flowchart of a suffix EGK code decoding process. FIGS. 16A , 16 B and 16 C shows a CABAC residual block syntax arrangement. The images in the drawings are simplified for illustrative purposes and are not depicted to scale. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the Figures, except that suffixes may be added, when appropriate, to differentiate such elements. The appended drawings illustrate exemplary configurations of the invention and, as such, should not be considered as limiting the scope of the invention that may admit to other equally effective configurations. It is contemplated that features or steps of one configuration may be beneficially incorporated in other configurations without further recitation. DETAILED DESCRIPTION The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any configuration or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other configurations or designs. The techniques described herein may be used for wireless communications, computing, personal electronics, etc. An exemplary use of the techniques for wireless communication is described below. FIG. 1 shows a block diagram of a configuration of a wireless device 10 in a wireless communication system. The wireless device 10 may be a cellular or camera phone, a terminal, a handset, a personal digital assistant (PDA), or some other device. The wireless communication system may be a Code Division Multiple Access (CDMA) system, a Global System for Mobile Communications (GSM) system, or some other system. A handset may be a cellular phone, wireless device, wireless communications device, a video game console, a wirelessly-equipped personal digital assistant (PDA), a laptop computer, or a video-enabled device. The wireless device 10 is capable of providing bi-directional communications via a receive path and a transmit path. On the receive path, signals transmitted by base stations are received by an antenna 12 and provided to a receiver (RCVR) 14 . The receiver 14 conditions and digitizes the received signal and provides samples to a digital section 20 for further processing. On the transmit path, a transmitter (TMTR) 16 receives data to be transmitted from the digital section 20 , processes and conditions the data, and generates a modulated signal, which is transmitted via the antenna 12 to the base stations. The digital section 20 includes various processing, interface and memory units such as, for example, a modem processor 22 , a video processor 24 , a controller/processor 26 , a display processor 28 , an ARM/DSP 32 , a graphics processing unit (GPU) 34 , an internal memory 36 , and an external bus interface (EBI) 38 . The modem processor 22 performs processing for data transmission and reception (e.g., encoding, modulation, demodulation, and decoding). The video processor 24 performs processing on video content (e.g., still images, moving videos, and moving texts) for video applications such as camcorder, video playback, and video conferencing. The controller/processor 26 may direct the operation of various processing and interface units within digital section 20 . The display processor 28 performs processing to facilitate the display of videos, graphics, and texts on a display unit 30 . The ARM/DSP 32 may perform various types of processing for the wireless device 10 . The graphics processing unit 34 performs graphics processing. The techniques described herein may be used for any of the processors in the digital section 20 , e.g., the video processor 24 . The internal memory 36 stores data and/or instructions for various units within the digital section 20 . The EBI 38 facilitates the transfer of data between the digital section 20 (e.g., internal memory 36 ) and a main memory 40 along a bus or data line DL. The digital section 20 may be implemented with one or more DSPs, micro-processors, RISCs, etc. The digital section 20 may also be fabricated on one or more application specific integrated circuits (ASICs) or some other type of integrated circuits (ICs). The techniques described herein may be implemented in various hardware units. For example, the techniques may be implemented in ASICs, DSPs, RISCs, ARMs, digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, and other electronic units. FIG. 2A shows an exemplary H.264 standard range register 50 and FIG. 2B shows an exemplary H.264 standard offset register 60 . The basic idea of the binary arithmetic coding process is recursive interval division. The arithmetic decoding engine core keeps two registers. The first register is a range register 50 with 9-bits. The second register is an offset register 60 which is 9-bits in a regular mode and 10-bits in a bypass mode. FIG. 2C shows an exemplary H.264 standard most probability symbol (MPS) case generally denoted by reference numeral 50 A, and FIG. 2D shows an exemplary H.264 standard least probability symbol (LPS) case generally denoted by reference numeral 50 B. The range register keeps track of the width of the current interval. The offset is from the bit-stream and a point to the current location within the range. It should be noted that many of the equations and expressions set forth below use syntax similar to C or C++ computer programming language. The expressions are for illustrative purposes and can be expressed in other computer programming languages with different syntax. When decoding a bin, the range is divided into two subintervals rLPS 52 and rMPS 54 depending on the context to decode a specific bin. The subintervals rLPS 52 and rMPS 54 are defined in equation Eqs.(1) and (2) r LPS=range* p LPS, and   (1) r MPS=range* p MPS=range*(1 −p LPS)=range− r LPS,   (2) where pLPS is the probability of the least probability symbol; and pMPS is the probability of the most probability symbol. The subinterval rLPS 52 and rMPS 54 where the offset falls, decides whether the bin is a MPS or a LPS bin. If the offset is >=rMPS, the bin is a LPS bin. Otherwise, the bin is a MPS bin. After the bin is decided, the range and offset are updated. The term pMPS is the probability. The probability should within 0 to 1. The term rMPS is the range*pMPS. The summation of the probabilities of MPS and LPS should be equal to 1. In various configurations below, flowchart blocks are performed in the depicted order or these blocks or portions thereof may be performed contemporaneously, in parallel, or in a different order. FIG. 3 a sample (psuedocode) instruction set of a H.264 standard arithmetic decoding process 100 for one bin. The instruction set indicates that both the range register 50 and offset register 60 are 9 bits. The range register 50 configuration is also indicated. The instruction set indicates that the range is within 2 8 <=range<2 9 . The arithmetic decoding process 100 is abbreviated and begins at an instruction where a determination is made whether range is >offset>=0. If the determination is “No,” the process 100 ends. However, if the determination is “Yes,” the next set of instructions is an if-else set. The if statement checks to see if the offset is >=rMPS. If the determination is “Yes,” the bin is a LPS case. Then the range is updated to a new range (range_new) set equal to the subinterval rLPS ( FIG. 2D ) and the new offset (offset_new) is set equal to offset−rMPS. If the if condition is “No,” then the bin is a MPS case. Then the range is updated to a new range (range_new) set equal to the subinterval rMPS and the new offset (offset_new) is set equal to offset. FIG. 4 shows a flowchart of a H.264 standard renormalization process 150 . After decoding one bin, the range and the offset will be renormalized to keep the precision to decode the next bin. The standard renormalization process 150 ensures that the most significant bit (MSB) of the 9-bit range register 50 is always 1, as represented in FIG. 2A . The standard renormalization process 150 begins with block 152 where a decision is made whether the range is <0X100. At block 152 , the value of the range is compared with 256 (or 0x100) If the determination is “No,” the process 150 ends. However, if the determination at block 152 is “Yes,” then block 152 is followed by block 154 . At block 154 , the range is left shifted by one bit denoted by range=range<<1. Likewise, the offset is left shifted by one bit, denoted by offset=offset<<1. The offset is also set to offset (bitwise OR) read_bits ( 1 ). The expression offset (bitwise OR) read_bits ( 1 ) represents the value of the RANGE/OFFSET registers shifted left by one bit. After the shift, the least significant(right most) bit is 0. The expression read_bits ( 1 ) reads one bit from the bitstream and this one bit is added to the least significant(right most) bit of offset register 60 . Block 154 loops back to block 152 described above. The loop of blocks 152 and 154 are repeated until the determination at block 152 is “No,” which completes the renormalization process 150 . FIG. 5 shows a flowchart of a H.264 standard normal decoding mode process 200 . In the standard decoding process 200 , to avoid multiplication, a 64×4 look up table (LUT) is used to approximate the rLPS set forth in equation Eq.(1) above. The range is approximated by equal-partitions of the 9-bit range register 50 into four cells. The pLPS is approximated by 64 quantized values indexed by a 6-bit context state. Therefore, at block 202 , the rLPS is calculated according to equation Eq.(3) r LPS= lut LPS[ ctxIdx ->state][(range>>6)&3]  (3) where ctxIdx is an input to the process 200 , represents the index to the context state and provides state information; range>>6 represents a right shift by 6 bits or a division by 2 6 ; and the result of (range>>6)&3 extracts bits 7-6 (the 2 bits after the MSB) in the range register 50 used to address the LUT. The expression ctxIdx->state can take a value from 0 to 63 which is used in the 64×4 LUT to get the rLPS. For example, if a range is 0b1 xx yy yyyy, the range will be within 0x100 to 0x1FE, and (range>>6)&3 is used to get “xx” of the range. The expression & is a bitwise AND function. At block 202 , the rMPS is also calculated according to equation Eq.(4) r MPS=range− r LPS   (4) where rLPS is calculated in equation Eq.(3). Block 202 is followed by block 204 where a determination is made whether the offset>=rMPS. If the determination is “Yes,” then block 204 is followed by block 206 where the bin, range and offset are calculated according to equations Eq.(5), (6) and (7) bin=!ctxIdx->valMPS   (5) range=rLPS, and   (6) offset=offset− r MPS   (7) where !ctxIdx->valMPS denotes an expression where ctxIdx->valMPS can take a value 0 or 1, and “!” means bit flip. The term ctxIdx is the input parameter to the function, and it provides the state and valMPS information. The term valMPS represents the bin output in the MPS case. Block 206 is followed by block 208 where a determination is made whether ctxIdx->state is equal to 0. If the determination at bock 208 is “Yes,” then block 208 is followed by block 210 where ctxIdx->valMPS is assigned to equal !ctxIdx->valMPS. Block 210 is followed by block 212 . Additionally, if the determination at block 208 is “No,” then block 208 is also followed by block 212 . At block 212 , ctxIdx->state is assigned to equal TransIndexLPS(ctxIDx->state). After each bin is decoded, the state/valMPS associated with each ctxIdx needs to be updated. The terms TransIndexLPS/TransIndexMPS are just 2 LUTs defined in the H.264 standard to calculate the state transition. Returning again to block 204 , if the determination at block 204 is “No,” then block 204 is followed by block 214 where bin and range are calculated according to equations Eq.(8) and (9) bin=ctxIdx->valMPS; and   (8) range=rMPS.   (9) Block 214 is followed by block 216 where ctxIdx->state is assigned to equal TransIndexLPS(ctxIDx->state). Both blocks 212 and 216 proceed to block 218 where the renormalization process 150 takes place. Block 218 ends the process 200 . FIG. 6 shows a general flowchart of a H.264 standard bypass decoding mode process 250 . For the bypass decoding mode process 250 . In the H.264 standard bypass decoding mode process 250 , the offset is shifted left by 1 bit and 1 bit is read from the bit stream. The new offset is compared with the range to determine whether the bin is 1 or 0. The standard bypass decoding mode process 250 begins with block 252 where the offset is set equal to offset <<1 where <<1 represents multiply by 2 or a left shift by 1. Furthermore offset is set equal to offset (bitwise OR) read_bits( 1 ). Block 252 is followed by block 254 where a determination is made whether offset is >=range. If the determination is “Yes,” then block 254 is followed by block 256 where bin and offset are calculated according to equations Eq.(10) and (11) Bin=1; and   (10) Offset=offset−range.   (11) If the determination is “No,” then block 254 is followed by block 258 where the bin is set equal to zero (0). Blocks 256 and 258 end the process 250 . It should be noted that the term bin is also the same as bit. FIG. 7 shows a flowchart of a H.264 standard terminate decoding process 300 . When decoding the bin indicating the end_of_slice_flag and the I-Pulse Code Modulation (I_PCM) mode, a special decoding routine the standard terminate decoding process 300 is called. The standard terminate decoding process 300 begins with block 302 where the range is decremented by 2 (range=range−2). Block 302 is followed by block 304 where a determination is made whether the offset is >=range. If the determination at block 304 is “Yes,” then the bin is set equal to one (1) at block 306 . However, if the determination at block 304 is “No,” then block 304 is followed by block 308 where the bin is set equal to zero (0). Block 308 is followed by block 310 where the renormalization process 150 ( FIG. 4 ) is performed. Both blocks 306 and 310 end the H.264 standard terminate decoding process 300 . During the CABAC initial stage, the range register 50 ( FIG. 2A ) is set to 0x1FE, 9 bits are read from the bitstream to set the initial offset register 60 . As can be readily seen from above, the 9 bits are used to represent both the range and offset. Therefore, there are a great number of bit wise operations in the CABAC core processes. In the H.264 standard normal decoding mode process 200 ( FIG. 5 ), whenever an LPS case, since the LPS probability is <0.5, the new range will be <0x100. Thus, renormalization is needed to bring the range>=0x100. In the new exemplary configuration, a count_leading zero (CLZ) instruction is used to calculate the amount of left shift needed instead of using a loop. Whenever a MPS case, since the MPS probability is >=0.5, the new range will be from 0x080 to 0x1FE. Therefore, at most one left shift is needed for renormalization to bring the most significant bit (MSB) to 1. At the same time, the offset is left shifted by the same amount and new bits are read from the bit stream to fill it up. Moreover, in the H.264 standard bypass decoding mode process 250 , the offset is always left shifted by 1 and 1 bit is read from the bitstream. This requires very frequent renormalization and reading of bits from the bit-stream both of which are very computationally costly. FIGS. 8A and 8B show a modified range register 400 and an offset register 410 of an exemplary configuration. The range register 400 and the offset register 410 maybe 32 or 64 bits. For illustrative purposes, the disclosure describes the implementation of a 32 bit range register 400 and offset register 410 . During the CABAC core initial stage, the range register 400 should be set to 0xFF000000=0x1FE<<23, the offset register 410 should be set to the first 4 bytes read from the bit-stream since the starting bit position of the CABAC part bit-stream is byte-aligned. As shown in FIG. 8A , the range register 400 is comprised of a plurality of parts. In the exemplary configuration, the 32 bits are divided into a leading zeros part 402 , an effective 9-bits part 404 , and a trailing zeros part 406 . The bitpos (bit position) is indicated by the number of leading zeros bits in the leading zeros part 402 and is calculated using a Count_leading_zeros instruction. The bitpos in the 32 bit implementation is 11 bits. The number of trailing zeros, in the trailing zeros part 406 is (32−9−bitpos)=(23−bitpos). The number of bits in at least one part of the range register 400 may be varied. The two bits after the first bit 1 from the most significant bit (MSB) is extracted from the range register 400 and used to look up the rLPS. The looked up value is left shifted by (23−bitpos) to align with the effective 9-bits part 404 in the range register 400 . The remaining algorithm is almost the same except a more efficient renormalization is used. Whenever range is less than 0x100, both range and offset are left shifted by 24 bits (3 bytes), 3 extra bytes are read from the bitstream and appended to the offset register 410 . Therefore, all the bit-stream access is byte-based. This exemplary configuration is an example for illustrative purposes. Moreover instead of 32 bits more or less bits can be used. Furthermore, while the description herein describes bytes which is 8 bits, any number of multiple bits in lieu of the byte arrangements described herein may be used in a renormalization process without iterative loops. FIG. 8C shows a block diagram of a video processor 24 having a processor circuit 24 A and a decoder engine 24 B. The decoder engine 24 B has the range and offset registers 400 and 410 . The video processor 24 communicates with a Look-Up-Table (LUT) 420 for the rLPS. The box 420 is shown in a dotted line to denote that it may be in the video processor 24 or external to the video processor 24 . The video processor 24 carries out the processes set forth below. FIG. 9 shows a flowchart of a normal decoding mode process 450 . The normal decoding mode process 450 is similar to the normal decoding mode process 200 ( FIG. 5 ). The primary differences include blocks 452 and 460 . At block 452 , bitpos is set equal to count_leading_zeros (range). Furthermore, rLPS is calculated according to equation Eq. (12) r LPS= lut LPS[ ctxIdx ->state][(range>>(29−bitpos))&3]<<(23−bitpos)   (12) where ctxIdx is an input to the process 450 , represents the index to the context state and provides state information; and the result of range>>(29-bitpos))&3 extracts the 2 bits after the leading 1. The expression <<(23-bitpos) is to used to align with the range. The expression ctxIdx->state can take a value from 0 to 63 which is used in the 64×4 LUT to get the rLPS. In FIG. 9 , blocks 204 , 206 , 208 , 210 , 212 , 214 and 216 correspond to the same numbered blocks in FIG. 5 . Hence, no further discussion is necessary. However, the renormalization block of 212 in FIG. 5 is substituted with the renormalization 1 process 500 of FIG. 10A . FIG. 10A shows a flowchart of a first renormalization (renormalization 1 ) process 500 . The first renormalization process 500 begins with block 502 where a decision is made whether the range is <0X100. If the determination is “No,” the process 500 ends. However, if the determination at block 502 is “Yes,” then block 502 is followed by block 504 . At block 504 , the range is shifted by 24 bits denoted by range=range<<24. Likewise, the offset is shifted by 24 bits, denoted by offset=offset<<24. The offset is also set to offset (bitwise OR) read_bytes ( 3 ). Thus, after the offset is shifted left by 24 bits, the right most 24 bits of offset register 410 are all 0. Then 3 bytes (24 bits) are read from the bit stream, and this is added to the offset register 410 . As can be seen, the first renormalization (renormalization 1 ) process 500 performs a multi-bit alignment of a register at the same time without an iterative loop operation. In the exemplary configuration, the multi-bit alignment of the range register 400 and 410 occurs in intervals of bytes. FIG. 10B shows a flowchart of a second renormalization (renormalization 2 ) process 600 . The second renormalization process 600 begins with block 602 where a decision is made whether the range is <0X200. If the determination is “No,” the process 600 ends. However, if the determination at block 602 is “Yes,” then block 602 is followed by block 604 . At block 604 , the range is shifted by 16 bits denoted by range=range<<16. Likewise, the offset is shifted by 16 bits, denoted by the offset=offset<<16. The offset is also set to offset (bitwise OR) read_bytes ( 2 ). Thus, after the offset is shifted left by 16 bits, the right most 16 bits of the offset register 410 are all 0. Then, 2 bytes (16 bits) are read from the bit stream, and this is added to the offset register 410 . FIG. 10C shows a flowchart of a third renormalization (renormalization 3 ) process 700 . The third renormalization process 700 begins with block 702 where a decision is made whether the range is <0X1000000. If the determination is “No,” the process 700 ends. However, if the determination at block 702 is “Yes,” then block 702 is followed by block 704 . At block 704 , the range is shifted by 8 bits denoted by range=range<<8. Likewise, the offset is shifted by 8 bits, denoted by offset=offset <<8. The offset is also set to offset (bitwise OR) read_bytes ( 1 ). Thus, after the offset is shifted left by 8 bits, the right most 8 bits of offset register 410 are all 0. Then, 1 byte (8 bits) are read from the bit stream, and this is added to the offset register 410 . FIG. 11 shows a flowchart of a bypass decoding mode process 800 . In the bypass decoding mode process 800 , the range is right shifted by 1 and compared with the offset register 410 . Thus, the second renormalization process 600 is performed first at block 802 . This is to ensure there are at least 10 bits in the range and offset registers 400 and 410 , or the range is >=0x200 before the right shift. Block 802 is followed by block 804 where the range is set equal to range>>1. In FIG. 11 , the blocks 254 , 256 and 258 correspond to the same numbered blocks in FIG. 6 . Hence, no further discussion is necessary. FIG. 12 shows a flowchart of a terminate decoding process 900 . The terminate decoding process 900 begins with block 902 where bitpos is set equal to Count_leading_zeros(range) and range is set decremented by (2<<(23-bitpos)). Block 902 is followed by block 304 where a determination is made whether the offset is >=range. In FIG. 12 , steps 304 , 306 and 308 correspond to the same numbered blocks in FIG. 7 . Hence no further discussion is necessary. Like FIG. 7 , after block 308 , normalization takes place. However, in FIG. 12 , the first normalization process 500 of FIG. 10A is used at block 910 where block 910 follows block 308 . Both blocks 306 and 910 end the terminate decoding process 900 . Multiple Symbol Decoding for Bypass Mode The bypass decoding mode process 800 applies to two cases, either to sign or exponential Golomb binarization (EG) code. For a case where bypass bin is a sign, only one bypass bin is decoded for each motion vector difference (mvd) or coeff_level_minus1. The EG code only appears as a suffix of the bin strings of an absolute motion vector difference (abs_mvd) or abs_coeff level_minus1. And only those bins with an abs_mvd>8 or an abs_coeff_level_minus1>13 contain a suffix of the EG code. Table 1 identifies a bin string with a prefix and suffix for abs_coeff level_minus 1. Table 2 identifies a bin string with a prefix and suffix for abs_mvd. The term coeff_level_minus1 is from the transform coefficient levels and abs represents the absolute value. Table 3 summaries the EG code prefix and suffix. With a bit rate increase (quantization step QP decrease, residual coefficients level increase), it is expected that the residual coefficient decoding will increase proportionally since the major increase will be in the EG code of abs_coeff_level_minus1. In a software implementation, it is important to improve the EG decoding by decoding multiple bins at the same time. In a hardware implementation, if hardware (HW) is designed such that multiple bins can be decoded within 1 cycle, it can put an upper bound on the CABAC decoding of any bit-rate bitstreams. Since there is no context involved in the bypass mode, the use of 32 bit range and offset register make multiple bypass bin decoding in one shot possible. The EC code and the terms residual coefficients level increase and residual coefficient decoding are known in the H.264 standard. The term “one shot” means decoding all the bits of a codeword at the same time instead of decoding one by one. As will be seen from the description herein, the exemplary configuration can speed up the EG code decoding. TABLE 1 abs_coeff_level Bin string abs_coeff_level-1 Prefix: TU code Suffix: EG0 code 0 0 1 1 0 2 1 1 0 3 1 1 1 0 4 1 1 1 1 0 5 . . . . . . 1 1 1 1 1 1 1 1 1 1 1 1 0 13 1 1 1 1 1 1 1 1 1 1 1 1 1 0 14 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 18 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 19 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 0 20 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 21 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 22 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 1 . . . . . . . . . TABLE 2 abs_mvd Bin string abs_mvd Prefix: TU code Suffix: EG3 code 0 0 1 1 0 2 1 1 0 . . . . . . 7 1 1 1 1 1 1 1 0 8 1 1 1 1 1 1 1 1 0 9 1 1 1 1 1 1 1 1 1 0 0 0 0 10 1 1 1 1 1 1 1 1 1 0 0 0 1 11 1 1 1 1 1 1 1 1 1 0 0 1 0 . . . 1 1 1 1 1 1 1 1 1 0 . . . 15 1 1 1 1 1 1 1 1 1 0 1 1 0 16 1 1 1 1 1 1 1 1 1 0 1 1 1 17 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 18 1 1 1 1 1 1 1 1 1 1 0 0 0 0 1 . . . 1 1 1 1 1 1 1 1 1 1 0 . . . 31 1 1 1 1 1 1 1 1 1 1 0 1 1 1 0 32 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 33 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 34 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 1 . . . 1 1 1 1 1 1 1 1 1 1 1 0 . . . 63 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 0 64 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 65 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 . . . . . . . . . TABLE 3 EG code prefix and suffix Num of bits in EG suffix EG_prefix_value EG code prefix EG0 EG3 EG0 EG3 0 Non 3 0  0 1 0 1 4 1 = 0b 1  8 = 0b 1 0 0 0 1 1 0 2 5 3 = 0b 1 1 24 = 0b 1 1 0 0 0 1 1 1 0 3 6 7 = 0b 1 1 1 56 = 0b 1 1 1 0 0 0 . . . . . . . . . . . . . . . As shown in Tables 1 and 2, the EG code contains a prefix and, in most cases, a suffix. The prefix is unary coded. The number of bins in the suffix is determined by the prefix. By way of an example specified in the Table 3 below, if the EG code prefix is “10”, then the number of bits in the EG 0 /EG 3 suffix is 1/4 as specified in the 2 nd row in Table 3. Table 3 summarize the prefix and suffix of a EG 0 code and a EG 3 code. Theoretically, the prefix/suffix part can be decoded as in FIGS. 13A and 14A . FIG. 13A shows a sample instruction set for a prefix EG code decoding process 1000 . FIG. 13B shows a range and offset relationship diagram the prefix EG code decoding process of FIG. 13A . The sample instruction set for process 1000 evaluates whether the offset is less than a set of threshold T 1 , T 2 , T 3 and T 4 where T 1 is equal to ½ of the range; T 2 is ¾ of the range; T 3 is ⅞ of the range; and T 4 is 15/16 of the range. If the offset is less than T 1 , range is right shifted by 1 and the bit 0 is returned. If the offset is less than T 2 , offset=offset−T 1 , and range is right shifted by 2 and the bits 10 are returned. If the offset is less than T 3 , offset subtracted and set to T 2 and range is right shifted by 3 and the bits 110 are returned. If the offset is less than T 4 , offset subtracted and set to T 3 and range is right shifted by 4 and the bits 1110 are returned. In FIG. 13B , the values of offset at T 1 , T 2 , T 3 and T 4 are shown in relation to the range. FIG. 14A shows a sample instruction set for a suffix EG code decoding process 1010 . FIG. 14B shows a range and offset relationship diagram for the suffix EG code decoding process of FIG. 14A . FIG. 14A shows a sample instruction set for a suffix EG code decoding process 1010 . The sample instruction set for process 1010 evaluates whether the offset is less than a set of threshold T 1 , T 2 , T 3 , T 4 , T 5 , T 6 and T 7 where T 1 is equal to ⅛ of the range; T 2 is 2/8 of the range; T 3 is ⅜ of the range; T 4 is 4/8 of the range; T 5 is ⅝ of the range; T 6 is 6/8 of the range; and T 7 is ⅞ of the range. If the offset is less than T 1 , the bits 000 are returned. If the offset is less than T 2 , offset=offset−T 1 , and the bits 001 are returned. If the offset is less than T 3 , offset subtracted and set to T 2 and the bits 010 are returned. If the offset is less than T 4 , offset subtracted and set to T 3 and the bits 011 are returned. If the offset is less than T 5 , offset subtracted and set to T 4 and the bits 100 are returned. If the offset is less than T 6 , offset subtracted and set to T 5 and the bits 101 are returned. If the offset is less than T 7 , offset subtracted and set to T 6 and the bits 110 are returned. Else offset is offset subtracted and set to T 7 and the bits 111 are returned. After any of the returns, range is right shifted by 3. In FIG. 14B , the values of offset, at T 1 , T 2 , T 3 , T 4 , T 5 , T 6 and T 7 are shown in relation to the range. FIG. 15A shows a flowchart of a prefix EGK code decoding process 1100 . FIG. 15B shows a flowchart of a suffix EGK code decoding process 1200 . An exemplary software implementation for decoding the prefix or suffix is shown. Since decoding each bin will right shift range by 1 and the range must >=0x100 after decoding the last bin, the range/offset are first renormalized such that range>=0x1000000. This way, it can accommodate to decode up to 16 consecutive bins. In a simulation, with a QP set to 1, the recorded maximum number of bins in EG code prefix/suffix was 9. For example, decoding each bit will consume 1 bit in the range register. If range>=0x1000000, after decoding the last bit, the range will be >=0x100. Thus, there are 16 bits which can be decoded. This is possible with the 32 bit range register 400 . The prefix EGK code decoding process 1100 begins with block 1102 where the third renormalization process 700 takes place. Block 1102 is followed by block 1104 where threshold is assigned to the range where the range is right shifted by 1. Furthermore, a prefix is assigned to 0. Block 1104 is followed by block 1106 where a determination is made whether the offset is >=threshold. If the determination at block 1106 is “Yes,” block 1106 is followed by block 1108 . At block 1108 , the range is right shifted by 1, the threshold is incremented by the range and the prefix +=(1<<k) and k++. The expression prefix +=(1<<k) is essentially expressed as prefix=prefix+(1<<k); and k++ increments k by 1 for the loop. Block 1108 is followed by block 1110 where the offset is −=(threshold−range). The expression offset −=(threshold−range) is also expressed as offset=offset−(threshold−range). Block 1110 ends the process 1100 . At block 1106 , if the determination is “No,” block 1106 proceeds to block 1110 . The term k is the input to the DecodeEGKPrefix and DecodeEGKSuffix function. As the input to DecodeEGKPrefix function, it should be 0 for EG 0 and 3 for EG 3 code. The input to DecodeEGKSuffix function is the value k come out of the DecodeEGKPrefix function. The expression prefix +=(1<<k) is also shown in Table 3 below. For example, 1110 (4 th row) means the prefix is 7 for EG 0 code, which is 0b 111=(1<<0)+(1<<1)+(1<<2). The expression offset is −=(threshold−range) is the same as offset=offset−(threshold−range). The suffix EGK code decoding process 1200 begins with block 1202 where the third renormalization process 700 takes place. Block 1202 is followed by block 1204 where suffix is set to 0. Block 1204 is followed by block 1206 where a determination is made whether k is greater than 0. If the determination is “No,” the process 1200 ends. However, if the determination is “Yes,” then block 1206 is followed by block 1208 where range is right shifted by 1 and k is decremented by 1. Block 1208 is followed by block 1210 where a determination is made whether offset is >=range. If the determination is “No,” then block 1210 returns to block 1206 . However, if the determination at block 1210 is “Yes,” block 1210 is followed by block 1212 where suffix is +=(1<<k) and offset is −=range. The expression suffix +=(1<<k) calculates the value of a binary string. For example, 0b 1010=(1<<3)+(1<<1) and the Offset=offset−range. Block 108 is followed by block 1110 where offset is assigned to threshold−range. Block 1110 ends the process 1100 . At block 1106 , if the determination is “No,” block 1106 proceeds to block 1110 . Experimental Results Tables 4-5 show the MIPS and cycles/function_call comparison between the standard and the new optimized core. These numbers are obtained on the Kayak sequence on DSP simulator, with level 3 compiler optimizations and with default data and instruction cache size. TABLE 4 MIPS Comparison between Standard and New Core Bit Rate Decode Decision Decode Bypass Decode EGK Overall MIPS Mbps QP Original Optimized Original Optimized Original Optimized Original Optimized 6.40 20 179.64 117.41 20.71 10.80 10.05 3.83 541.01 451.10 2.55 28 72.44 47.90 6.87 3.58 5.40 2.07 256.36 220.18 1.53 32 44.38 29.80 3.80 1.98 3.46 1.33 172.33 150.87 0.91 36 27.01 18.66 2.15 1.12 2.34 0.90 117.67 105.29 0.55 40 16.95 12.03 1.23 0.64 1.44 0.55 84.00 76.78 TABLE 5 Cycles/Function Call Comparison between Standard and New Core Bit Decode EGK Rate Decode Decision Decode Bypass Opti- Mbps QP Original Optimized Original Optimized Original mized 6.40 20 28.62 18.70 19.75 10.30 164.06 62.47 2.55 28 28.26 18.68 19.77 10.31 161.28 61.91 1.53 32 27.78 18.65 19.78 10.32 160.51 61.64 0.91 36 26.90 18.58 19.82 10.32 160.98 61.79 0.55 40 26.13 18.54 19.83 10.32 160.32 61.58 Tables 4 and 5 shows a comparison of the bit rate, the quantization step size QP to the decode decision processes 200 and 450 of FIGS. 5 and 9 . Tables 4 and 5 also shows a comparison for the decode bypass processes 250 and 800 of FIGS. 6 and 11 and the decode process of the EGK code. Table 4 also shows the results of the MIPS. If 64 bit registers is used and special attention is paid at the CABAC initial stage, one will able to make the reading 4 bytes aligned and save cycles further. The threshold to do the first, second and third renormalization processes 500 , 600 and 700 , shown in FIGS. 10A , 10 B and 10 C, can be changed to 0x100000000 so a common renormalization routine is applied. This will change the frequency of reading bytes from the bitstream. It can also change the renormalization check frequency. For example, the renormalization check at the beginning of FIG. 15B at block 1202 can be omitted. In FIG. 9 , the first renormalization process 500 performed at block 460 can be moved to the beginning of the normal decoding mode process 450 . If a 32 bit range register is used and the renormalization threshold is 0x10000, after decoding the first symbol, the smallest possible range register is 0x600. A range register of 0x600 is still >0x100 and can decode the next symbol without renormalization. Hence, with more than a 9 bit range/offset register, it enables decoding multiple bins without re-normalization. Since the original re-normalization is bit-based therefore it is very costly. Thus, the arrangement of the range register 400 can simplify the hardware architecture to decode 2 consecutive normal mode symbols. FIGS. 16A , 16 B and 16 C shows a CABAC residual block syntax arrangement. To decode 2 consecutive normal mode symbols the significant_coeff_flag and last_significant_coeff_flag, as seen in FIGS. 16A and 16B , are decoded in pairs. If the significant_coeff_flag is 0, this indicate the coefficient is a zero coefficient and there is no last_significant_coeff_flag. If the significant_coeff_flag is 1, this indicates the coefficient is a non-zero coefficient and the next symbol to decode is last_significant_coeff_flag. Therefore, the value of the pair can take either 0 or 10 or 11. Since the pair needs to be decoded for each residual coefficients of the 4×4 block, the potential speedup/saving is quite significant. The terms significant_coeff_flag and last_significant_coeff_flag are defined in the H.264 standard. The matrix or block 1400 in FIG. 16C is an exemplary illustration of a data set. The values in the Table 1350 in FIG. 16B are derived from the data set of FIG. 16C . The syntax element stream 1300 is derived from the Table of 1350 . As long as there are enough bits in the range/offset register, the renormalization check can be skipped. In one or more exemplary configurations, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. The previous description of the disclosed configurations is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to these configurations will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other configurations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the configurations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

A device employing techniques to optimize Context-based Adaptive Binary Arithmetic Coding (CABAC) for the H.264 video decoding is provided. The device includes a processing circuit operative to implement a set of instructions to decode multiple bins simultaneously and renormalize an offset register and a range register after the multiple bins are decoded. The range register and offset registers may be 32 or 64 bits. The use of a larger range register allows renormalization to be skipped when enough bits are still in the range register.

The present application is a complete application claiming priority based on co-pending Provisional Application Ser. No. 60/053,406, filed Jul. 22, 1997 and entitled "IMMEDIATE RESPONSE MEDICAL ANALYZER HAVING MULTIPLE TEST MODULES". BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed generally to a stationary or portable diagnostic system or electroanalytical systems for analyzing preselected characteristics of a patient's blood and other fluids. More particularly the present invention is concerned with a portable diagnostic device or analytic instrument that includes a plurality of test modules for analyzing various body fluids of a patient, wherein the modules are coupled to a common display, printer, power supply, and communication ports. The portable diagnostic device interfaces and utilizes disposable cartridges, reagent diagnostic test strips, or other means to determine, for example, a patient's blood pH, pO 2 , pCO 2 , Na + , Ca ++ , K + , hematocrit, glucose and/or other parameters including oxygen saturation, coagulation or hemoglobin fractions. The modules may determine the parameters through a variety of methods such as electrochemical, electrical, optical, or mechanical analysis of a fluid biological sample extracted from the patient. The disposable cartridge may utilize a bank of sensors for the pertinent electroactive species to provide input in the form of analog electrical signals for the relevant determinations. II. Related Art During clinical, surgical, diagnostic and other medical procedures the measurement of certain physical/chemical characteristics or conditions of the blood and other fluids of a patient are useful in order to evaluate the condition of a patient. For example, a patient's blood pH, pO 2 , pCO 2 , Na + , Ca ++ , K + , hematocrit, glucose and other parameters including oxygen saturation coagulation or hemoglobin fractions may be measured. These conditions may provide important indications of the patient's stability including, for example, the efficiency of the blood/gas exchange occurring in the lungs of the patient, the relative acid/base balance, or the concentration of certain indicative ion species in the blood. Such determinations are particularly useful in emergency circumstances. In the past, the equipment provided to make such determinations has typically been complex and permanently installed in a hospital laboratory. Also, the user operating the equipment has been oftentimes required to be a highly-trained and skilled technician, which thereby increases the cost of operating the equipment and limits the number of potential users. With such equipment, in order to analyze a sample of fluid from the patient, a sample must be drawn from the patient and delivered to the laboratory, avoiding all external contacts. During the transfer and delivery, the drawn fluids may be kept in close proximity to ice packs in order to maintain sample integrity. The sample is then injected into a designated receptacle of the diagnostic equipment and the equipment operated to perform the diagnostics on the sample. This procedure is time consuming, labor intensive, and usually disadvantageous in the operating room, emergency room or other area of the hospital, or outside the hospital where time is of the essence. Hence, portable devices that reduce the time required to make accurate blood-gas and related determinations, in order that proper and more timely corrective steps may be taken, are highly sought. Many situations arise where it is impractical to deliver a patient's fluid sample to a hospital laboratory in order to analyze the patient's blood analytes. It would be desirable for paramedics and in-home health care providers, for example, to analyze a sample at the point of collection without having to first deliver a sample to a hospital laboratory. To this end, it would also be desirable to provide a single portable diagnostic device capable of analyzing simultaneously several samples and/or conducting several electrochemical, electrical, optical, or mechanical analysis simultaneously or in rapid succession to determine, a patient's blood pH, pO 2 , pCO 2 , Na + , Ca ++ , K + , hematocrit, glucose and other parameters including oxygen saturation, coagulation or hemoglobin fractions. There have been attempts at point-of-care blood-gas analysis. One on-site analytic device, described by Enzer et al in U.S. Pat. No. 4,786,394, is designed for direct connection to a heart/lung machine to monitor critical blood gases during open-heart surgery. It employs a discardable sensor cartridge which contains a bank of sensors for making the electrochemical determinations. A further patent to Enzer et al (U.S. Pat. No. 4,397,725) also discloses a clinical blood chemistry analyzer in which a discardable cartridge interfaces with an analytical machine. Although the analyzer may be utilized on-site during surgery, the device disclosed by Enzer remains relatively stationary and immobile. Morris et al in U.S. Pat. No. 5,325,853 (of common assignment with the present invention) disclose a self-calibrating disposable sensor system. Carter et al in U.S. Pat. No. 5,628,890 describe an electrochemical sensor for measuring the glucose concentration in a patient's blood. Such a sensor is limited to the particular analyte being measured and requires an interface with an electrochemical sensor. Stark in U.S. Pat. No. 5,433,197 describes a non-invasive glucose measurement device that requires illumination of the patient's eye with near infrared radiation. The capability of the Stark device is limited to determining blood glucose. Phillips et al in U.S. Pat. No. 5,563,042 describe a device that measures glucose concentration in whole blood optically using a reflective reading apparatus and a whole blood glucose test strip. A further reference is contained in U.S. Pat. No. 4,849,340 to Oberhardt discloses a device that measures coagulation in whole blood using a liquid assay device and method. Although somewhat useful, such devices are limited in application and address only part of the drawbacks of prior systems. There remains a need for a rapidly responding, portable blood chemistry analytical device. A need also exists for a single, portable, self-calibrating, instant activation, rapid response diagnostic device capable of simultaneous analysis of several samples and/or conducting several electrochemical, electrical, optical, or mechanical analysis simultaneously or in rapid succession to determine, blood pH, pO 2 , pCO 2 , Na + , Ca ++ , K + , hematocrit, glucose and other parameters including oxygen saturation, coagulation or hemoglobin fractions. The present invention meets these needs and overcomes the disadvantages of prior devices. SUMMARY OF THE INVENTION The present invention provides a point-of-care medical analyzer that enables an operator without special training or skills to obtain rapid, accurate blood-gas, glucose, and other analyte determinations at the time and location the sample is drawn. The device is compact, light-weight, easily transported and ready for immediate use. The analyzer is designed for rapid processing of electrical signals generated by electrochemical, electrical, optical, or mechanical sensors of an associated module having both calibration and sample determination modes and utilizing one-time use or disposable cartridges. The modules may be removed from the analytic device and interchanged. The plug-in disposable electrochemical sensor cartridge which may be similar to that depicted in the above-cited U.S. Pat. No. 5,325,853, the entire contents of which are hereby incorporated by reference for any purpose, employs an array of sensors, typically a bank of aligned sensors on a ceramic chip in a flow-through chamber. The flow-through chamber, as packaged, further contains a calibration medium retained in situ with respect to corresponding sensors to be calibrated such that when the disposable cartridge is activated in conjunction with insertion into and electrical connection with the analytical device, calibration signals are produced by the sensors on the disposable cartridge which enables immediate automatic calibration of the sensors. The sample may thereafter be introduced through an entry port in a manner which causes the calibration medium to be displaced from the flow-through chamber and replaced by the blood or other fluid sample then in direct contact with the sensors. The array of electrochemical sensors then produces electrical signals in accordance with the characteristics of the sample. The disposable sample cartridge carries a heater in the form of a thin or thick film resistor carried on the sensor chip itself designed to bring the sample quickly to the temperature desired for the analytic determination based on an optical sensor and remote control from within the analytical device. Such a system is depicted in Hieb et al., U.S. Pat. No. 5,232,667, assigned to the same assignee as the present invention, the entire disclosure of which is incorporated herein by reference for any purpose. Once the desired temperature is reached, the electrical signals from the electrochemical sensors are received and processed by the portable analyzer and the results made available on a display and/or in printed form. Other suitable "cartridges" are used in association with the other modules. It will be appreciated by those skilled in the art that the analytical instrument is required to provide only the signal processing systems for calibration and measurement. The remote temperature sensing and control system provided in the portable instrument, for example, controls only the electric input to a heater located in the disposable cartridge. There is no heating system, per se, in the analytical instrument. The heating control system preferably includes an IR probe or other remote temperature sensing device which is used in association with a programmed control or set point temperature to rapidly establish and maintain the desired temperature in the disposable cartridge. Further details of the temperature control arrangement are contained in the above-referenced patent issued to Hieb et al (U.S. Pat. No. 5,232,667). In operation, the fully portable analytical instrument is brought to the point of sampling, i.e., the location of the patient. A predetermined number of disposable cartridges are removed from a temperature-stabilized packaging and inserted or plugged into corresponding modules of the analyzer. The instrument is activated; the sensors are calibrated automatically and the calibration electronically compensated with respect to an ensuing set of measurement signals. A sample of interest is obtained from the patient and a portion may immediately be transferred to the sample inlet port of the calibrated sensor system on each disposable cartridge. The sample displaces the calibration medium to a storage chamber and avails the electrochemical sensors for an immediate sensing of the corresponding species of interest in the sample. Other types of sensors including electrochemically active reagent test strips may be exposed to the sample and inserted into a corresponding module. The user determines the particular needs for testing and determines which modules to attach to the base unit of the immediate response medical analyzer. Plugging the disposable cartridges and inserting relevant sample strips into the respective module of the portable medical analyzer activates the system. The activation of the system also activates the temperature control system which maintains the sensor chip, or equivalent, at the desired calibration and analysis temperature for those determinations that require temperature control. If the sample within the cartridge is at a different temperature, the temperature control system reacts quickly and controls the sensors to restore the desired temperature to the system. Of course, some determinations, including glucose measurement, do not require temperature control. After the determinations have achieved equilibrium and the corresponding signals have been read by the analyzer, the analyzer computes the results based on the sensor outputs. The results are made immediately available on a combination touch screen LCD display and as a printed record using an integral printer. It is anticipated that the entire operation from first insertion of the cartridges and activation of the system until printout of the results, assuming the immediate availability of the sample, can be achieved in less than three minutes. In addition to the rapid availability, the results are also stored by the device in memory for later retrieval by touch screen, printer or to be sent via a communications port to an external or remote computer or laboratory. OBJECTS It is accordingly a principal object of the present invention to provide a portable, rapidly responding, point-of-care medical device having several modules capable of independently determining a plurality of predetermined analytes from a fluid biological sample. Another object of the present invention is to provide a rapidly responding, portable medical analytical instrument capable of interfacing with several self-contained, self-calibrating, or pre-calibrated, disposable fluid sample devices of varying construction. Yet another object of the present invention is to provide a portable sophisticated medical analyzer capable of simplistic user friendly operation. A further object of the invention is to provide a self-contained point-of-care blood analyte analyzer capable of instant activation and almost immediate response in determining a patient's blood pH, pO 2 , pCO 2 , Na + , Ca ++ , K + , hematocrit, glucose and other parameters including oxygen saturation, coagulation or hemoglobin fraction. These and other objects, as well as these and other features and advantages of the present invention will become readily apparent to those skilled in the art from a review of the following detailed description of the illustrated embodiment in conjunction with the accompanying claims and drawings in which like numerals in the several views refer to corresponding parts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a perspective view of the multiple module portable point-of-care analyzer of the present invention; FIG. 1b is a perspective view of a multiple module similar to the analyzer of FIG. 1a with an additional module attached; FIG. 2 is a partially exploded perspective view of the device of FIG. 1 showing a module removed; FIG. 3 is a fragmentary, partially exploded, lower perspective view of the device showing a module removed from the analyzer; FIG. 4 is a partially exploded perspective view of the top section of the device of FIGS. 1 or 2, without the removed module and including a non-contact temperature sensor probe and print roll; FIG. 5 is a schematic system block diagram for one embodiment of the multi-module or multiple module portable medical analyzer of the invention; FIG. 6 is an electrical schematic illustrating the connection between a glucose module and the integrated circuit of the analyzer; FIG. 7 is a fragmentary perspective view of a cartridge receptacle interface with a cartridge inserted; FIG. 8 is a perspective view of a disposable cartridge for use with the analyzer of the invention; FIG. 9 is a schematic diagram of an analog interface subsystem associated with FIG. 5; FIG. 10 is a partially exploded perspective view of an alternate embodiment of the portable point-of-care analyzer of the present invention; and FIGS. 11-13 depict schematic block diagrams of examples of modules that interface with each of the modular interface system types depicted in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention includes a point-of-care and immediate response portable medical analyzer that features automated calibration and analysis for a variety of uses. The analyzer includes several interchangeable modules that allow the user to analyze several samples or analyze one sample for several predetermined criteria at the point-of-care without extended delays. Thus blood-gas analysis results can be made available to the attending physician, surgeon, or other health care provider within a minute or two after the drawing of a sample. Moreover, it takes no particular skill to operate the portable medical analyzer inasmuch as both calibration and sample analysis have been automated in conjunction with a unique self-calibrating system. A disposable plug-in cartridge unit interfaces with the medical analyzing device or a reagant strip is automatically interfaced with an output system. While the illustrated embodiments described below are directed to blood-gas and blood-electrolyte analysis, it will occur to those skilled in the art that these are meant as examples and are in no way intended to introduce limitations to the scope of the invention and that the system can be adapted to other analyses involving blood or other body sera without departing from the essential premises of the invention. It will be appreciated from the views of FIGS. 1a-4 that one advantage of the portable analyzer of the invention is that it is mechanically simple and eliminates the need for medical personal to transport samples to a plurality of diagnostic analyzers. With this in mind attention is directed first to FIGS. 1a and 1b where a portable analytic device in accordance with the present invention is shown generally at 10. The base unit device 10 includes a housing 12, a first integrator permanent module 14, a second removable module 16, a touch screen interactive display 18, a printer 20, and a replaceable power supply 22. The base unit enclosed in the housing 12 also includes an upper section 24 and a lower section 26, and includes a void area to define a handle 28. An attached removable second module is shown at 16. The first integrator permanent module 14 includes a cartridge receptacle 30 having a pair of guide flange 32 to hold and guide the sides of a disposable cartridge 140 (see FIG. 8) into the receptacle 30. As shown in FIG. 1b, an additional module 33 may be interposed between the module 16 and the basic analytical device 10. The embodiment of FIG. 1b notably further includes an additional interface section 34 which includes a plug receptacle 35 represents another interface to receive yet another measurement module having an input and output integrated into the basic analytical unit 10. A remote temperature sensor 36 is positioned in the receptacle 30 (see FIG. 4) beneath an opening 37, thereby providing for temperature measurements of the cartridge 140 as further described below. As best seen in connection with FIG. 4, the interactive display 18 includes a touch screen with an 8×8 grid mask 42 associated with an output LCD window or cover 44 which is fastened beneath an opening 46 in the top housing member 24. The power supply 22 includes a battery pack, which supplies power through ON-OFF control to the microprocessor, cartridge interface and the touch screen 18. Common voltages are supplied as needed within the processing circuitry through a variety of voltage converters which also supply the liquid crystal display bias and the back lighting for the touch screen 18. This system is considered conventional to those skilled in the art, and further explanation is believed unnecessary. Module 16 is a glucose meter that includes a receptacle 48 for insertion of a test strip. Without any limitation intended, the module 16 may utilize, for example, the motherboard and test receptacle of a SURESTEP glucose meter available from Lifescan, Inc. Milipitis, Calif. The motherboard and test strip receptacle are mounted to the module and are electrically coupled to a connector that interconnects a communication line and power supply to the internal electrical components contained within housing 12. A relay and control line may be added to allow control of the power supplied to the module 16. Module 33 may be capable of performing a coagulation assay such as PT (prothrombin time), PTT (activated partial thrombo-plastin time) or ACT (activated clotting time). This module may measure whole blood coagulation time and includes a system for receiving a liquid sample into a reaction chamber containing a reagent material which reacts with the sample to perform the detmination. The reaction can be monitored optically to determine the assay time. Such a system is illustrated and described in U.S. Pat. No. 4,849,340 to Oberhardt, the details of which are deemed incorporated by reference herein for any purpose. The output signals from that module are digitized and processed within the module itself prior to being communicated to the base unit. Those skilled in the art will appreciate that modules 14, 16 and 33 may represent different modular units of suitable construction modified as needed to interface with electrical components of the present invention. Optionally, additional modular units may be added in stacked or separate arrangements. The appropriate interconnects including communication and power supply links can be provided as direct plug-in linkages from the base unit and through other sensor modules. Without any limitation intended, dedicated removable modular units may include a visible light sensing device that makes co-oximetry measurements such as total hemoglobin concentrations (tHb), oxyhemoglobin (O 2 Hb), carboxyhemoglobin (COHb) and methemoglobin (MetHb) of a blood sample contained in a cartridge or cuvette may be mounted in a module and interconnected with the present invention. Modules of this type are available from AVOX Systems Incorporated of San Antonio, Tex. Those skilled in the art will appreciate that the mother board and optical bench of such a sensor may be removed and electrically connected within the housing 12 of the analytic device 10. An external connector may be used to interconnect the sensor module's communication lines and power supply to the device 10. A relay with one control line and may be added to allow control over the module by the device 10. Also, the controlling software may be modified to allow control of the module via the device 10. FIGS. 2 and 3 illustrate the removeability of the second module 16. The module 16 locks onto the housing 12 (FIG. 1a) may utilize a male and female quick release lock of known suitable construction. When the module 16 is locked in place, the electrical contacts 38 of the module engage with the electrical contacts 40 protruding from the housing 12. Those skilled in the art will appreciate that a plurality of electrical contacts may be utilized to form a serial port or other electrical connection of known suitable construction to thereby interconnect the internal electrical components of the module 16 with an integrated circuit and central processing unit (CPU) contained within the housing 12. The module 16 includes a receptacle 48 adapted for receiving a disposable diagnostic test strip or electrochemical sensor of known suitable construction. The module 33 of FIG. 1b attaches to the housing 12 in a similar manner and includes pass-through interfaces and housing lock system to accommodate the module 16 in a piggyback or tandem stacked arrangement. Note that module 33 also has a further plug receptacle 35a situated to accommodate yet annother modular sensor. In accordance with the operation of the portable medical analyzer of the invention, a typical operating system is shown in block diagram in FIG. 5. Additional details of subsystems are illustrated in FIGS. 6 and 9. The interface of module 16 with the integrated circuit contained within housing 12 is depicted in FIG. 6 and the analog interface system is depicted in FIG. 8. Additional information can be gleaned with reference to the schematic block diagram of FIG. 5. The system is operated by a programmed central processing unit 70 which operates in conjunction with a voltage controlled oscillator 72, real-time clock 74 with associated non-volatile random access memory (novram) 76 random access memory (RAM) 78 and erasable programmable read only memory (EPROM) 80. The system further includes a communication integrated circuit 82 (RS232 with interface 84 and a typical circuit connector 86). Also included is an interface 88 for the interactive touch screen display 18. A printer interface 90 for printer output and LCD interface 92 are also shown. Various switches and an alarm or beeper device 94 are connected through a bit output device at 96. An analog interface 98 interconnects the heater system 100, sensor interface 102 and module interfaces 104-110. Those skilled in the art will appreciate that additional module interfaces 112-116 may be interconnected with integrated circuit 82 via a multiplexor 118. Additionally, module interfaces 120-124 may be directly connected to the central processing unit 70. In this manner, those skilled in the art will appreciate that a variety of modules having various processing components may be rendered compatible with the present portable device 10. For example, FIG. 6 shows a glucose measuring module of common known construction electrically coupled to an immediate response medical analyzer (IRMA). FIG. 11 depicts a typical module of a class designed to interface with the instrument 10 through any of interface modules and may include a CPU 150 connected to the module interface through a serial input/output device. The module further typically includes a sensor interface 154 with associated measurement circuitry 156 signal conditioning system 158 and A/D signal converter 160. A CPU controlled DAC signal generator 162 provides an analog interface with a temperature control system and sensor interface 154. The module depicted in FIG. 12 is of a class that are designed to connect to a module interface through a multiplexer and communication IC as at 118 and 82. This includes any of the module interfaces 112, 116. It will be appreciated that the modules 16 and 33 are compatable with this type of interface. FIG. 13 depicts yet another type of connected device compatable with the module interfaces 104-110. With respect to FIG. 9, it will be appreciated that once the disposable cartridge is plugged into the analyzer and the analyzer is turned on, calibration signals are almost immediately available on a clock controlled or prioritized channel selective interface bus as at 130 such that by employing a serial clock, the serially obtained data available on the bus 130 can be processed by a serial to parallel converter 132 interfacing with the central processing unit 70 to sort out the multiple signals being received from A-to-D converters 134-142. Corrective data where applicable and reference measurements are provided via the A-to-D converter 142 from a multiplexer channel control 144 that receives input from a variety of sources including barometric pressure sensor, temperature, reference electrode signals and an oxygen bias signal, if used, from the sensor interface 102. The clock controlled CPU interfaces with both the multiplexer channel control and the remaining electrochemical sensors via the serial to parallel converter in a manner which uses the signals together with the available calibration condition data from the multiplexer via A-to-D converter 142 to accurately calibrate each of the species sensors for subsequent use in making a determination in the sample. It will be appreciated that in this manner, each disposable cartridge is automatically individually calibrated with respect to the measurements to be made once connected to the analyzer and activated. Determination of each sample is then made pursuant to an individualized calibration based on the disposable cartridge itself and not based on calibration of any of the components in the portable analytical device. FIG. 8 depicts a perspective view of the disposable cartridge 34 designed for use in association with the medical analyzer 10 of the invention. The cartridge 34 includes a substantially planar base member or plate 146 and a housing 148 fixed to the base member 146. One end of the cartridge is formed to include a handle with a gripping flange 150 to obtain a better grasp of the cartridge 34. Side flange members 152 extend from the sides of the planar base and slide under guide flanges 32 of the cartridge receptacle 30. FIG. 7 shows the cartridge 34 aligned and engaged with receptacle 30 and having an injection syringe 154 positioned to introduce a sample into a sample port 156. The cartridge is further provided with an array of electrical leads or terminals as at 158 configured to connect with corresponding terminals in the analytical instrument cooperating in the exchange of electrical signals between the analytical instrument and cartridge in a well-known manner. These terminals connect to corresponding conductors (not shown) of the receptacle 30 which provide all necessary input and output connections to control the functions and transmit the necessary signals between the cartridge and the analytical instrument. The cartridge housing 148 further defines a flow-through analytical cell chamber or volume containing an array of electrochemical sensors 160-168 connected to a relatively larger waste receptacle chamber 170. The cartridge waste volume 170 includes a retention maze in the form of a plurality of partitions as at 172. As recognized above, the cartridge and module 14 are described in greater detail in U.S. Pat. No. 5,325,853, the entire disclosure of which has been incorporated herein by reference. An alternate embodiment of the portable device 10 is shown generally at 200 in FIG. 10. The device is adapted for receiving a cassette 202 in which is electrically integrated a plurality of testing modules 204-208. The cassette 202 is provided with a cover that engages with the base of cassette 202. A rechargeable, replaceable battery pack 212 is shown elevated above the portable device 200. The device 200 also includes an interactive display 214 and printer 216. The cassette 202 includes electrical connectors that electrically interconnect each module 204-208 with the electrical components contained within the device 200 (including a central processing unit and integrated circuit). The modules 204-208 may be removed from the cassette 202 and are interchangeable. In this manner, the user may either analyze several samples using similar modules or may select different modules to perform varying analysis and diagnostics of a single sample. This invention has been described herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.

A portable device that includes a plurality of test modules for analyzing preselected concentrations of various body fluids of a patient. The portable diagnostic device interfaces and utilizes disposable cartridges and reagent diagnostic test strips and other fluid sample diagnostic devices to determine the amounts of preselected parameters in a patient's blood through either electrochemical, electrical, optical, or mechanical analysis. The disposable fluid sample diagnostic devices may include sample chambers with inlet ports, electrical, physical, or chemical sensors, in situ calibration media, a plurality of electrical interface terminals, and temperature control elements. An electrical interface interconnects the various test modules with one or more corresponding integrated circuits which in turn are electrically coupled to a common interactive display, printer, power supply, and communication ports.

BACKGROUND The invention relates to 2',5'-oligoadenylates which possess a cyclophosphate group at the 3' end and a free OH group at the 5' end, to a process for preparing these compounds, to a pharmaceutical preparation comprising them, and to the use of these compounds for treating external papillomatoses. The invention relates to novel chemical compounds, specifically 2',5'-oligoadenylate-2',3'-cyclophosphates of the general formula ##STR2## in which 0≦n≦10, in particular from ≧0 to 10, preferably 1 or 2. The compounds in which n=1 or 2, in particular, may advantageously be used for medicinal purposes, specifically for the topical treatment of dermal and epithelial lesions which are caused by papilloma viruses. Papillomatoses which are caused by papilloma viruses of the Papovaviridae family are infectious diseases which are widely distributed in humans and animals. Currently, more than 60 types of human papilloma viruses are known. All these viruses possess a similar structure. In each case, their genome consists of a double-stranded, covalently closed annular DNA of 8000 base pairs which encodes the virion proteins and the proteins which are required for the intercellular development of the virus. In the infected cell, the papilloma virus genome is replicated over many generations in the form of episomes (dozens of copies per cell). Mature virions are only formed in the cells at the final stage of differentiation. Under persistent conditions, it is only the first genes of the papilloma virus genome which are expressed, with these genes causing an alteration in the cell phenotype and in this way leading to the formation of papillomatoses. In the infected cells, a particular moiety of the virus genome has a probability, which is dependent on the virus type and on other factors, of being able to be incorporated into the cell genome, something which can then trigger conversion to malignancy. It is known that a substantial number of human tumors are the result of the conversion of papillomatoses to malignancy. These tumors thus represent a consequence of persistent, latent viral infections. In this context, anogenital papillomatoses which are transferred by the sexual route are the most dangerous as far as conversion to malignancy is concerned (see M. Spitzer, Obstet. Gynecol., 1989, vol. 73, N3, pp. 303-307; H. zur Hausen, A. Schneider, The Role of Papilloma viruses in Human Anogenital Cancer, in: The apapovaviridae (N. P. Alzman ed.), 1987, vol. 2, pp. 245-263; H. zur Hausen, Papilloma viruses as Carcinoma-viruses, in: Adv. in Virus Ontology (G. Klein ed.), 1989, vol. 8, pp. 1-26). Since papillomatoses are precancerous disorders which are easy to diagnose, the development of many tumors can be prevented by treating benign papillomatoses, i.e. before malignant conversion of the infected cells takes place. At present, the most important methods for treating papillomatoses are surgical removal of the papillomas and necrotization by means of electrocauterization, cryocauterization or laser cauterization (see Virus infections. Etiology, epidemiology, clinics, pathogenesis and diagnosis. Rep. Col. of Scient. Public., Sverdlovsk, 1985 (in Russian)). For this purpose, use is made of liquid oxygen, and acids and mixtures thereof (nitric acid, oxalic acid, lactic acid, etc.), which bring about necrosis of the surrounding healthy tissue and, at the application site, lead to scar formation and frequently to recurrences and to the appearance of new papillomas close to the site from which the old ones were removed (see S. A. Bashi, Cryoterapia versus podophyllin in the treatment of genital warts, Int. J. Dermatol., 1985, vol. 24, N 8, pp. 535-536). The effectiveness of medicinal methods for treating papillomatoses using podophyllotoxin and interferon is low and is also associated with powerful side effects and/or after-effects, even when therapeutic doses are used. The biological activity of podophyllin can be explained by its antimitotic effect, which is comparable to that of colchicin. Its use frequently causes local reactions (inflammations, allergic contact dermatoses, occasional skin erosions, etc.) and also undesirable after-effects such as peripheral neuropathy, tachypnea, hematuria and spontaneous abortion (see K. R. Beutner, Podophyllotoxin in the treatment of genital human papilloma virus infections. Seminars in Dermatology, 1987, vol. 6, N1, pp. 10-18). In the case of papillomatoses, the administration of interferon has only a slight effect, and the doses which are employed for this treatment can lead to suppression of the immune system and to the triggering of autoimmune disorders (see F. G. Bruins, A. J. C, von den Brule, R. Mullnik, G. M. M. Walboomers, C. J. Meijer, R. Willemze, J. Invest. Dermatol., 1989, vol. 93, N4, pp. 544-545; M. Foldvan, A. Moreland, M. Nezei, ibid., pp. 550; G. Gross, Roussaki, ibid., pp. 553M. Niimura, imbid., pp. 567). Synthetic analogs of 2',5'-oligoadenylates (2,5 A) are known for the fact that they exhibit immunosuppressant activity and have previously been proposed for use in surgical transplantation. It has been established that oligoadenylates are less toxic, more specifically active and more effective, as mediators of the effects caused by interferon, than are immunosuppressants (see A. Kimchi et al., U.S. Pat. No. 4,378,352 (1983)). The same effect is also achieved by a synthetic 2,5 A which contains a terminal morpholine group (see R. Torrence et al., U.S. Pat. No. 4,515,781 (1985)). 2,5 A analogs which possess at least three adenosine fragments are known to be active inhibitors of viral protein synthesis in vitro (see Jan M. Kerr et al., U.S. Pat. No. 4,21,P,746 (1980)). While some synthetic analogs of 2,5 A-oligo-3'-deoxyadenylates and their derivatives inhibit the infection and transformation of animal cells with herpes simplex and Epstein-Barr viruses, in particular in in-vitro cultures, they are nevertheless inactive in the case of cells which are already infected or transformed (see R. I. Suhadolnik et al., U.S. Pat. No. 4,464,359 (1984); R. I. Suhadolnik et al., U.S. Pat. No. 4,539,313 (1985); R. I. Suhadolnik et al., U.S. Pat. No. 4,708,935 (1987)). It is possible to use 2,5 A for treating infectious diseases which are caused by cytomegalovirus, hepatitis B virus and varicella zoster viruses (see European Patent Application No. 121 635 (Au, No. J, Dk, Fi, Fr, Es), 1984). SUMMARY OF THE INVENTION The object of the invention is to make available an effective pharmaceutical having a selective effect for the treatment of cutaneous and epithelial lesions which are caused by papilloma viruses. The object of the invention is achieved by the provision of 2',5'-oligoadenylate-2',3'-cyclophosphates of the formula I ##STR3## in which 0≦n≦10, in particular from ≧0 to 10, preferably 1 or 2. The invention also relates to processes, proceeding from poly(A), for preparing the novel compounds, as described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1: HPLC analysis of mixture A (2',5'-oligoadenylate-2,',3'-cyclophosphates). Column: Diasorb NH 2 , 4×150 mm. Mobile phase: A--20% CH 3 OH; B=2M AcONH 4 in 20% CH 3 OH. Flow rate: 0.7 ml/min; 0'-2'--1% B, 2'-14'--0.5% B/min, 14'-50'--2% B/min. Detection at 260 nm. Composition of the mixture corresponding to the absorption at 260 nm: 23% monomer (8.7 min), 22.5% dimer (17.5 min), 14% trimer (23 min), 6.8% tetramer (26.8 min). FIG. 2: HPLC analysis of the purified 2',5'-trimer-(A)- and tetramer-(B)-2',3'-cyclophosphates. Column composition of the mobile phase and flow rate as in FIG. 1, gradient--2% B/min. DETAILED DESCRIPTION OF THE INVENTION These compounds may be prepared in a manner known per se from poly(A) having irregular 2',5' and 3',5' internucleotide bonds in accordance with a known process (see A. M. Michelson: In the Chemistry of the Nucleosides and Nucleotides (Academic Press) 1963, pp. 418 and 419) by means of the chemical polymerization of 2'(3')-adenosine monophosphate. The subsequent cleavage of the 3',5' bonds in this polymer with B. intermedius ribonuclease (E.C.3.1.4.23) leads to a mixture containing monomers and 2',5'-oligoadenylates of differing length and possessing terminal 2',3'-cyclophosphate groups. The same results are also obtained using another two-stage process: 1. Cleaving the poly(A) with T2 ribonuclease (or similar ribonucleases), resulting in a series of 2',5'-oligoadenylates, with each oligomer constituting a mixture of 2',3'-cyclophosphate and 3'-monophosphate, and 2. treating this mixture with a 100-fold excess of BrCN in buffered aqueous solution, resulting in the conversion of the terminal 3'-phosphate group into the 2',3'-cyclophosphate group. These two synthesis routes may be depicted diagrammatically as follows: ##STR4## The resulting mixtures of 2',5'-oligoadenylates are analyzed and the desired oligonucleotides in accordance with formula I are purified by HPLC. There has hitherto been no report of 2',5'-oligoadenylates having a terminal 2',3'-cyclophosphate group as individual compounds. Both the 2'(3')-phosphate groups and the 2',3'-cyclophosphate groups in the 2',5'-oligoadenylates effectively prevent the hydrolysis of these compounds by cell enzymes. The efficacy of the 2',3'-cyclophosphate analogs as compared with the natural 2',5'-oligoadenylates containing the 5'-triphosphate group is explained by their greater ability to permeate cells due to their lower charge and their resistance towards hydrolysis by phosphodiesterases together with cell enzymes. The novel 2',5'-oligoadenylates are dissolved in water or aqueous solutions of neutral salts and applied once or twice daily to the dermal lesions (ordinary plane warts and plantar warts, condylomas, etc.) for 2 weeks. The active compound concentration is from 10 -4 to 10 -7 M. As a result of their having been treated, the condylomas stop growing and no new growth takes place; in most cases, the old condylomas remit within from 4 to 6 weeks. In the case of ordinary warts, the papules become flatter towards the end of the first week and disappear completely from 2 to 4 weeks after the beginning of the treatment. Patients suffering from plane warts are completely cured 1 month after beginning the treatment. During the treatment of papillomas, the new growths shrink, and smaller papillomas are sloughed off, after 1.5 to 2 weeks and there is complete retrogression of the dermal lesions within 1 month. In not one single case is there any scar formation. Nor is the healing process accompanied by toxic/allergic reactions or other side effects. While the concentration of the active oligoadenylates in the treatment solutions is at least two orders of magnitude higher than in the case of the interferon-induced cells, the total quantity of solution which is applied is, however, normally less than 1.0 ml. Therefore, even if all the oligoadenylates are absorbed, the average concentration in the cells and body fluids (blood, urine, etc.) is far below that in the non-induced cells. The concentration of the applied compounds can only transiently (immediately after treatment) be higher than that of their natural analogs in the normal cells and then only in the tissues in the immediate vicinity of the application site. The 2',5'-oligoadenylates can be readily degraded by nucleases and phosphatases which are present within and outside the cells of the organism. Adenylic acid and adenosine, which constitute customary cell metabolites whose average concentration in the cells is less than 10 -3 M, are then formed as end products. Both individual oligonucleotides of the formula I and mixtures which contain them can be used for treating dermal and epithelial lesions which are induced by papilloma viruses. The topical use of small doses of the novel 2',5'-oligoadenylates for treating papillomatoses is extremely effective, with no negative dermal reactions, nor any systemic side effects, being observed. In more than 80% of patients, treatment of lesions results in complete retrogression. No recurrences are observed after an observation period of 3 months. The novel preparation may be administered in various formulations which are acceptable for topical use. These formulations are prepared by the careful mixing or dissolution of the individual compounds, or their mixtures, with a pharmaceutically acceptable excipient using the customary techniques, with it being possible for the excipient to have very widely differing forms depending on the formulation of the preparation which is desired for the application, i.e. on the outer skin or on mucosal tissues. A very wide variety of pharmaceutical media, for example liquid excipients such as water, dimethyl sulfoxide in the presence or absence of alcohols, glycols, etc., or in the form of a pomatum, an ointment or a plaster, may be used for producing the preparations. It is particularly advantageous to formulate the abovementioned pharmaceutical preparations in a unit dose form in order to facilitate and simplify dosage. The expression "unit dose form" refers to physically discrete units each of which contains a specific quantity of active compound, which quantity is so calculated as to achieve, in combination with the requisite pharmaceutical excipient, the desired therapeutic effect. The appropriate dose for a single use for treating papillomatoses should be from 10 -9 to 10 -8 mol of active compound (n=1 and/or 2) per papule (from 3 to 5 mm in diameter). The total duration of the treatment is up to 30 days, with the preparation being administered daily. EXAMPLES The following examples illustrate the preparation of oligonucleotide mixtures and individual 2',5'-oligoadenylates. Chemicoenzymic synthesis, purification and analysis of the 2',5'-oligoadenylates All the reactions are carried out at room temperature. a) Synthesis of poly(A): 0.9 g (2.5 mmol) of adenosine-2'(3')-monophosphate in H + form and 1.2 ml (2.6 mmol) of tri-n-octylamine are dissolved in 30 ml of methanol/ethanol (1:1), with the solution being stirred for several hours. After that, the insoluble constituents are filtered off using a glass filter, after which the filtrate is evaporated to dryness using a rotary evaporator. The resulting solid is then dissolved in 10 ml of abs. dioxane and evaporated to dryness using a rotary evaporator. Both procedures are repeated twice. The resulting solid is then dissolved in 5 ml of abs. dioxane, after which 0.77 ml (3.75 mmol) of diphenylphosphoryl chloride are added dropwise while stirring with a magnetic stirrer. 3.3 ml (7.5 mmol) of tri-n-octylamine are then added. The resulting solution is then stirred for 1 hour, after which 0.77 ml of diphenylphosphoryl chloride and 3.2 ml of tri-n-octylamine are added and the mixture is stirred for a further 4 hours. The reaction mixture is then poured, while stirring, into 5 vol. of hexane/ether (4:6). The precipitate is then filtered off using a glass filter, washed with the abovementioned mixture and then with ether, and dried in vacuo. In this way, a white powder of polyadenylate possessing irregular 2',5' and 3',5' internucleotide bonds is obtained. The general formula of the mixture is (A2'(3')p--) n A>p, in which n=10. The dry polymer mixture is dissolved in 12 ml of water by adjusting the pH to 9.3 by means of adding conc. ammonia solution. After that, 3 vol. of ethanol are added, with the pH then being adjusted to 3.0 with 5M HCl. The precipitate which is formed after keeping the mixture at -18° C. is centrifuged off, washed with 75% ethanol and dried in a current of air. A substantial proportion of the monomer remains in the supernatant. b) Selective cleavage of the 3',5' internucleotide bonds by means of cleaving with binase The precipitate which is obtained in a) is dissolved in 40 ml of H 2 O, with the pH being adjusted to 7.0 using a 3M solution of tris base; after that, 2 ml of a solution of Bacillus intermedius RNAse (binase, E.C.3.1.4.23) (150 U/mg) are added and the mixture is then stirred for 10 to 12 hours. After that, the enzyme is extracted by extraction with the same volume of chloroform/isoamyl alcohol (24:1). The resulting aqueous phase contains a mixture of 2',3'-cyclophosphates of adenosine and 2',5'-oligoadenylates. c) Isolation of the individual compounds Preliminary separation of the individual components is effected by means of ion exchange chromatography using DEAE Spheron 1000 in the HCO 3 form (16×600 mm, 120 ml). Following deproteinization, the product obtained from the enzymic cleavage of poly(A) is concentrated by being subjected to rotary evaporation approximately 8 to 10 times and is then, after 10 vol. of ethanol have been added, kept at -18° C. for 12 hours. Following centrifugation (3000 rpm for 10 to 20 min), the precipitate is dissolved in water and loaded onto the column (optical density from 25,000 to 50,000 U at 260 nm). After the column has been washed with water and with 0.05M triethylammonium bicarbonate (pH 8.0), the products are eluted using a linear gradient of this salt (from 0.1 to 0.8M, total volume 1 L). The fractions which contain the enriched individual compounds are then evaporated to dryness on a rotary evaporator and lyophilized in order to remove the buffer components completely. The final purification of the individual compounds is effected by HPLC, as described below (loading of the semipreparative column with approx. 2000 U optical density). The desalting of the solution after the HPLC is effected by sorbing a 10- to 20-fold diluted solution onto small DEAE columns after washing with water, eluting with a small volume of 1M triethylammonium bicarbonate and lyophilizing the solution. d) Purification and analysis of the 2',5'-oligoadenylates by means of HPLC chromatography The ion exchange chromatography is carried out on an NH 2 -Diasorb column (8 μm, 4×150 mm for the analysis and 10 μm, 9.2×250 mm for the final preparative purification); linear gradient: eluent A--20% MEOH; B--2M AmAc, 20% MEOH, 2% B per mixture; flow rate--0.7 ml/min for the analytical column and 4 ml/min for the preparative column (FIGS. 1 to 3). Detection is effected using a UV monitor at 260 nm. On the basis of the optical density at 260 nm, the mixtures contain 40 to 50% monomer, approx. 20 to 30% diadenylate, approx. 5 to 15% triadenylate, 2 to 8% tetraadenylate and 2 to 7% higher oligoadenylates. The mean molar extinction coefficient was 15·10 3 per adenosine residue, 36.8·10 3 for the trimer and 45.8·10 3 for the tetramer. e) Determination of the composition of the individual compounds Each compound was kept at pH 1.0 (for 1 hour at 37° C.) in order to open the cyclophosphate group, after which it was dephosphorylated with bacterial alkaline phosphatase and subjected to alkaline hydrolysis of the internucleotide bonds (0.3M NaOH, for 48 hours at 20° C). The ratio of the end products (adenosine to adenosine-2'(3')-phosphate) was determined by HPLC. The results which were obtained in this context agree well with those which were predicted: Ado:AMP=1:1 for the dimer, 1:2 for the trimer and 1:3 for the tetramer. The standard error was less than 5%. On the basis of their HPLC mobility and NMR spectra ( 31 P and 1 H) the compounds resulting from the acid opening of the 2',3'-cyclophosphate group were identical to the known 2'(3')-phosphates of the corresponding oligoadenylates. On the other hand, the 2'(3')-phosphates which were obtained are converted quantitatively, in aqueous solution and at room temperature, into the starting 2',3'-cyclophosphates of the corresponding oligoadenylates by the action of BrCN (100-fold molar excess). f) Elucidation of the type of internucleotide bond Treatment of the 2',3'-cyclophosphates of the individual 2',5'-oligoadenylates with fresh binase under conditions which lead to complete cleavage into polyadenylic acid--adenosine--2',3'-cyclophosphate, does not result in any change in the HPLC separation profile and in the 31 P NMR spectra. The only peaks to be observed in the 31 P NMR spectra were those corresponding to the terminal cyclophosphate group (20 to 21 ppm) and the 2',5'-internucleotide phosphate (0.02 to 0.4 ppm), at a ratio of 1:1 for the dimer, 1:2 for the trimer and 1:3 for the tetramer. The standard error was less than 2%. The 3',5' bond (less than 1% of internucleotide phosphate) was only detected in the case of the tetramer. The oligoadenylates are colorless compounds and are readily soluble in water (up to 10 -2 M), dimethyl sulfoxide, aqueous ethanol or glycerol. They are soluble in neutral, aqueous solution at 4° C. for several months and for an unlimited period in frozen solution (-20° C.) or in the lyophilized state. PHARMACOLOGICAL EXAMPLES Clinical investigation of the pharmaceutical preparation was carried out in papillomatosis patients. The patients were treated with the Na or triethylammonium salt of the corresponding compound, which had been diluted down to the requisite concentration with water or 0.1M NaCl. The concentration of the active compound in the final solution was determined on the basis of the optical density of the solution at 260 nm and using the abovementioned molar extinction coefficients. The results which were obtained in this context are summarized below. The examples merely illustrate the invention and do not limit it. EXAMPLE 1 Clinical trial of 2',5'-triadenylate-2',3'-cyclophosphate (n=1, AIII) Diagnosis in the case of female patient M. (1958): sharp-edged condylomas. Findings: four condylomas (d=1 to 2 mm, h=2 to 8 mm) in the perineal region which were skin-colored, rough, elastic and sometimes painful. Accompanying illness: vaginitis. Application of AIII (10 -4 M), at the daily rate of approx. 50 μl per condyloma. On the 4th day, all the condylomas exhibited a rugose surface and they had completely disappeared on the 8th day. No recurrences were observed after 8 weeks. Diagnosis in the case of female patient P. (1950): multiple condylomas. Findings: 14 condylomas (d=2 to 8 mm, h=2 to 5 mm) in the perineal region which were elastic, skin-colored and sometimes painful. Application of AIII (10 -4 M) for 2 weeks at the daily rate of 50 μl per condyloma. On the 6th day, all the condylomas had shrunk to half to one third of their initial size and, on the 10th day, 8 condylomas had disappeared completely without leaving any traces on the skin. The remaining 6 condylomas were still present and reassumed their original size 3 to 4 weeks after the treatment had been terminated. The treatment was not repeated. No changes were to be observed at 10 weeks after the end of the treatment (no recurrences and no formation of new condylomas). Diagnosis in the case of female patient C (1958): plantar wart. Finding: a wart on the underside of the big toe (d=5 mm, h=3 mm) which was compact and of the same color as the surrounding tissue, and which had a rough surface and was very painful on walking. Application of AIII (10 -4 M) at the daily rate of 50 μl per wart. On the 6th day, the wart had become softer and the surface of the wart could be rubbed off on mechanical manipulation. On the 10th day, the wart had completely disappeared and there was no longer any sensation of pain on walking. No recurrences were found on monitoring after 12 weeks. The relevant site on the skin surface did not differ in any way from the surrounding tissue. Diagnosis in the case of patient C. (1926): papillomas. Findings: 7 papillomas were observed on the front and on the right-hand side of the neck, i.e. two large papillomas (d=3 and 2 mm, h=2.5 mm, dark brown) and 5 smaller papillomas (d=0.8 to 1.5 mm, 0.8 to 1.5 mm skin-colored). The papillomas appeared in 1982 during the menopause. Application of AIII (10 -5 M) for 2 weeks at a daily rate of approx. 50 μl per papilloma. On the 5th day, the smaller papillomas had lost color and had shrunk and become flattened. No further changes could be observed. 2 to 3 weeks after the end of the treatment, the papillomas once again exhibited their original shape and size. EXAMPLE 2 Clinical trial of 2',5'-tetraadenylate-2',3'-cyclophosphate (n=2, AIV) Diagnosis in the case of female patient S, 27 years of age: ordinary warts. Findings: three warts on the abdomen, 3 cm below the navel and of grayish color, prominent, diameter 2 to 3 mm. The warts were treated daily for two weeks with 1 to 3 drops of AIV (10 -5 M). On the 7th to 10th days after beginning the treatment, all the warts had shrunk and become flattened. One of the warts had completely disappeared at three weeks after the end of the treatment, as had the others at four weeks after the end of the treatment. There were no scar-like changes in the skin. Seven further patients exhibiting multiple warts, i.e. exhibiting condylomas (six patients), ordinary warts (three patients) and unidentified warts (four patients), were treated daily for two weeks with an aqueous solution (10 -5 M) of AIV. The condylomas were located on the external genitalia and on the chest, with the warts being located on the wrists, on the body and on the legs. In most cases, the condylomas and warts (in particular the former) shrank and became smaller after six to nine days of treatment. At 1 to 2 weeks after the end of the treatment, or during this period, three patients were already completely free of condylomas and two no longer exhibited any ordinary warts. At approx. 6 weeks after the end of the treatment, one patient was completely free of all six condylomas under the armpit. In two cases, the small condylomas (d<3 mm, 11 in all) on the external genitalia disappeared during or after the treatment, while the larger condylomas in the same region (d>5 mm, two in the first case and three in the second) regained their original size and form at 2 to 6 weeks after the treatment. While two of the six unidentified warts had disappeared at 2 to 3 weeks after treatment, the remainder did not show any reaction. In not one single case were negative reactions, vestiges on the skin or recurrences observed during the treatment or for 8 to 12 weeks thereafter. EXAMPLE 3 Clinical trial of mixture A (mixture of 2',5'-oligoadenylate-2',3'-cyclophosphates, n≧0) Two patients were tested, i.e. one exhibiting three ordinary warts (3 to 4 mm) on the neck, and a second exhibiting two pointed condylomas on the inner side of the leg. Each wart was moistened daily with 1 to 2 drops of a 10 -4 M aqueous solution of mixture A. On the 9th day of treatment, all the ordinary warts had disappeared. A small condyloma disappeared after 7 days of treatment, while another disappeared three weeks after the end of the treatment, i.e. five weeks after beginning the treatment. The results achieved clearly demonstrate the great efficacy of the investigated compounds and of the process for treating dermal and epithelial lesions caused by human papilloma viruses. In not one single case was the treatment of the papillomatoses with 2',5'-oligoadenylates accompanied by a painful or inflammatory reaction and a subjective or objective aggravation of the patient's condition. The high clinical efficacy of the 2',5'-oligoadenylates at very low dosage, and the absence of local reactions and systemic side effects, and also the freedom from relapses, provide proof of the advantages of the said compounds for treating papillomatoses. Similar results to those obtained in the treatment of papillomatoses were also achieved using previously known compounds, i.e. using 2',5'-oligoadenylates having natural adenosine residues and 2'(3')-phosphate groups (series B) or free 2'- and 3'-hydroxyl groups (series C) on the 3-terminal adenosine residue. In these cases, both the individual compounds, such as trimers and tetramers, or their mixtures with other oligomers trimers B and C, tetramers B and C, mixtures B and C prove to be extremely effective in the treatment of external papillomatoses.

An enzymatic synthesis is disclosed for papillomavirus inhibitors which are 2',5'-oligoadenylate-2',3'-cyclophosphates having the formula ##STR1## in which 0≦n≦10, in particular from ≧0 to 10, preferably 1 or 2. Pharmaceuticals which contain these compounds as the active ingredient, and their use to treat diseases caused by papillomaviruses are also discussed.

BACKGROUND OF THE INVENTION [0001] It is sometimes desirable to provide a walk-in, highly secured, lockable vault inside a building or habitat to protect property from damage or theft or to serve as a shelter from natural disaster or intruders. [0002] These walk-in vaults are often required to comply with various building codes and satisfy requirements set by regulatory bodies for security vaults. This has led to the walk-in vault being built in-place in a building by forming walls of substantial building material such as concrete, steel, or brick to form an enclosure which is fire-resistant and burglary-proof for a rated time. [0003] The fact that these walk-in vaults have to be built in-place makes them very expensive for the average person and prolongs construction time of the building. It also makes the addition of a vault to a building that is already constructed difficult. Thus it is desirable to have a fire-resistant, burglary-proof, walk-in security vault that can be built inexpensively and incorporated into a building quickly. SUMMARY OF THE INVENTION [0004] In accordance with one aspect of the invention, a modular vault comprises a plurality of side, end, and roof panels. The panels are ore-cast from a durable material and connected together to define a walk-in enclosure. A floor slab forms the base of the walk-in enclosure. A door frame is molded in at least one of the side or end panels. A door which controls access to the walk-in enclosure is hingedly attached to the door frame. Joint means for engaging abutting panels are provided on the inner surfaces and peripheral edges of the panels. A plurality of metal plates are attached to the inner surfaces of the panels at a location proximate the peripheral edges. The edges of the metal plates contact when the panels are connected by the joint means. A plurality of metal connectors are welded to the metal plates adjoining at corners of the abutting panels. The metal connectors seal the corners of the abutting panels, thereby making the walk-in enclosure substantially vapor-tight. [0005] In accordance with another aspect of the present invention, a unitary vault includes a housing body made of a durable material. The housing body defines a substantially vapor-tight enclosure. A door frame is fixedly mounted to a side of the housing body. A door providing access to the enclosure is hingedly attached to the door frame. A plurality of hooks are mounted on the housing body. The hooks facilitate hoisting of the housing body. BRIEF DESCRIPTION OF THE DRAWING [0006] [0006]FIG. 1 is a perspective view of one embodiment of the present invention. [0007] [0007]FIG. 2 is an exploded assembly view of the embodiment shown in FIG. 1. [0008] [0008]FIG. 3 is a side view of FIG. 1 in half section showing connections between adjoining walls and adjoining walls and roof. [0009] [0009]FIG. 4 is a perspective view of another embodiment of the present invention. [0010] [0010]FIG. 5 a shows one embodiment of the present invention being transported to a construction site. [0011] [0011]FIG. 5 b shows one embodiment of the present invention being set on the slab of a building with a crane. [0012] [0012]FIG. 6 shows how one of the embodiments of the present invention is incorporated into a building. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0013] Referring to the drawings wherein the reference characters are used for like parts throughout the several views, FIG. 1 depicts a walk-in vault 10 completely assembled and resting on a footing 15 at a construction site. [0014] As shown in FIG. 2, the walk-in vault 10 has a front wall 20 , rear wall 30 , side walls 40 , roof slab 50 , and floor slab 60 . While the walk-in vault 10 is illustrated as a four-wall embodiment, it should be understood that each wall may be constructed from a series of interlocking, pre-cast panels. [0015] The front wall 20 has a top edge 21 , a bottom edge 22 , an inner surface 23 , and an outer surface 24 . A pair of elongated grooves 25 run from the top edge 21 to the bottom edge 22 . The top edge 21 includes an outwardly extending ridge 26 integrally formed with the front wall 20 . [0016] A door frame 12 is integrally formed with the front wall 20 . A door 14 is attached to the door frame 12 in the front wall 20 by means of hinges 13 . The door 14 is preferably a fire-resistant, burglary-proof vault door with security locks and bolts. [0017] The rear wall 30 has a top edge 31 , a bottom edge 32 , an inner surface 33 , and an outer surface 34 . A pair of elongated grooves 35 run from the top edge 31 to the bottom edge 32 . The top edge 31 has an outwardly extending ridge 36 integrally formed with the rear wall 30 . [0018] The side walls 40 have top edges 41 , side edges 42 , bottom edges 43 , and an inner surface 44 . Each top edge 41 has an outwardly extending ridge 45 integrally formed with the side wall 40 . Each side edge 42 has an outwardly extending ridge 46 integrally formed with the side wall 40 . [0019] To form an interlocking walk-in space, the ridges 46 on the side edges 42 of the side walls 40 mate with the grooves 25 in the front wall 20 and the grooves 35 in the rear wall 30 . [0020] The roof slab 50 has a peripheral edge 52 , an inner surface 53 , and an outer surface 54 . Elongated grooves 55 and 56 are provided on the inner surface 53 of the roof 50 . The elongated grooves 55 and 56 run parallel to the peripheral edges 52 of the roof 50 . The elongated grooves 55 mate with ridge 26 on the front wall 20 and the ridge 36 on the rear wall 30 . The elongated grooves 56 mate with the ridges 45 on the side walls 40 . [0021] As shown in FIG. 3, apertures 70 are spaced along the perimeters of the front wall 20 , the rear wall 30 , and the roof slab 50 . The apertures 70 intercommunicate with the grooves 25 , 35 , and 55 and 56 in the front wall 20 , rear wall 30 , and roof slab 50 , respectively. Each aperture 70 has an upper portion 72 and a lower portion 74 . The upper portion 72 has a key-way 76 . [0022] Metal rods 80 are molded into the front wall 20 , the rear wall, 30 , and the side walls 40 . The metal rods 80 protrude through the ridges 26 , 36 , and 45 and 46 on the walls 20 , 30 , and 40 , respectively. Portions of the metal rods 80 protruding from top edges 21 , 31 , and 41 of the walls 20 , 30 , and 40 , respectively, mate with the apertures 70 in the roof slab 50 when the ridges 26 , 36 , and 45 on the top edges of the walls 20 , 30 , and 40 , respectively, mate with the grooves in the roof slab 50 . Similarly, portions of the metal rods 80 protruding from the side edges 42 of the side walls 40 mate with the apertures 70 in the walls 20 and 30 when the ridges on the side edges 42 of the side walls 40 mate with the grooves 25 and 35 in the walls 20 and 30 , respectively. [0023] Washers 82 are welded to the metal rods 80 to keep the connected walls from pulling apart. The spaces in the upper portion 72 of the apertures 70 may be filled with grout to prevent access to the metal rods. The key-ways 86 prevent grouts inserted into the spaces in the upper portion 72 of the apertures 70 from falling out. [0024] Metal plates 84 are cast in the walls 20 , 30 , and 40 and roof 50 . The metal plates 84 are held in place by means of studs 85 . The surfaces of the plates 84 are flushly arranged with the inner surfaces of the walls and roof flab. The plates 84 in the walls contact when the walls are fitted together. Contacting plates 84 are welded to metal connectors 86 using any suitable welding material. [0025] Advantageously, the double, fillet welds 88 formed by welding the plates 84 to the metal connectors 86 result in a stronger holding power than usually available if the plates 84 are directly welded together. Also, the continuity of the welds 88 provide a vapor-tight enclosure within the vault, thus protecting the contents of the vault from contaminants such as moisture and smoke and allowing the atmosphere in the vault to be controllable. The metal connectors 86 shield the fillet welds 88 from intruders, thus making it difficult for intruders to rupture the fillet welds 88 from outside the vault. [0026] The vault 10 is secured to the footing 15 by continuous, fillet welds 90 . The welds 90 help in providing a vapor-tight enclosure within the vault 10 and in preventing water from seeping into the vault to damage the property in the vault. The welds 90 may be covered by the floor slab 60 . [0027] Conduits may be provided in the walls to allow lighting and security systems and air passageways to be installed in the vault. [0028] The walls and roof are preferably pre-cast from monolithically poured concrete. The poured concrete may be reinforced with steel bars to prevent hairline cracking in the vault structure. Any other suitable material that satisfies requirements set by regulatory bodies for security vaults may also be used to pre-cast the walls, roof, and floor. The thickness of the walls, roof, and floor may be varied to suit the particular building in which the vault is to be used and to reduce the overall cost of the vault. [0029] The door frame 12 may be integrally formed in the front wall 20 by fitting the door frame 12 to an outer mold shell and pouring concrete monolithically into the mold cavity formed between the outer mold shell and an inner mold core. The concrete snugly holds the door frame 12 in place and eliminates the need for special fasteners to hold the door frame 12 to the front wall 20 . [0030] The floor slab 60 may be pre-cast at a manufacturing plant or formed at the construction site by pouring concrete onto the portion of footing 15 within the walk-in space defined by interlocking the walls 20 , 30 , and 40 . [0031] The vault 10 is generally assembled at a construction site as follows. The bottom edge 21 of the front wall 20 is positioned on a footing at the construction site. The bottom edges 43 of the side walls 40 are positioned on the footing and connected to the front wall 20 by mating the ridges 46 on the side edges 42 of the side walls 40 with the grooves 25 in the front wall 20 . The rear wall 30 is positioned on the footing and connected to the side walls 40 by mating the grooves 35 in the rear wall 30 with the ridges 46 on the side edges 42 of the side walls 40 . [0032] The walls 20 , 30 , and 40 are welded to the footing. A pre-cast floor slab 60 may be lowered into the walk-in enclosure defined by the interlocking walls 20 , 30 , and 40 . Alternately, concrete may be poured onto the portion of the footing within the walk-in enclosure formed by the walls. The poured concrete becomes the floor slab 60 . [0033] The roof slab 50 is placed on top of the walls 20 , 30 , and 40 by matching the grooves 55 and 56 on the roof 50 with the ridges 26 , 36 , and 45 on the top edges of the walls 20 , 30 , and 40 , respectively. Metal connectors 86 are welded to the metal plates 84 in the corners formed between adjoining walls and between the walls and the roof. [0034] An alternate embodiment replaces the front wall 20 , the rear wall 30 , the side walls 40 , the roof slab 50 , and the floor slab 60 with a unitary housing body 100 as shown in FIG. 4. The unitary housing body has a front portion 102 , a rear portion 104 , a first side portion 106 , a second side portion 108 , a roof portion 110 , and a floor portion 112 . [0035] The housing body is pre-cast from reinforced concrete by pouring concrete into a cavity defined by an inner mold core and an outer surrounding mold shell. A door frame 116 is integrally formed with the housing body 100 . A door 118 is mounted on the door frame 116 by means of hinges 120 . The door 14 is preferably a fire-resistant, burglary-proof vault door. [0036] Advantageously, the housing body 100 does not have seams that are prone to penetration by intruders. The enclosure defined within the housing body is also vapor-tight. [0037] To facilitate transporting of the housing body 100 , the roof portion 110 of the housing body 100 is provided with hooks 124 . The hooks 124 provide anchors for a crane to hoist the housing body 100 onto a truck or position the housing body 100 on a footing at a construction site. FIG. 5 a shows the housing body 100 being transported to a construction site on a truck 126 . FIG. 5 b shows a crane 128 engaging the hooks 124 of the housing body 100 and lowering the housing body 100 to a footing 130 at a construction site. FIG. 6 shows how the housing body 100 is incorporated into a building 132 at a construction site. [0038] The weight of a housing body pre-cast from reinforced concrete with strength of 3000 psi or greater may become quite substantial. To reduce the overall weight of the housing body 100 , the floor portion 112 of the housing body 100 may be omitted. If the floor portion 112 is omitted, a floor can be added to the housing body 100 at the construction site. This is done by molding a frame into the bottom of the housing body 100 and welding this frame to a similar frame at a footing in a construction site. Concrete is monolithically poured into the cavity defined by the frame attached to the bottom of the housing body 100 to form a floor. [0039] While the present invention has been described with respect to a limited number of preferred embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. The appended claims are intended to cover all such modifications and variations which occur to one of ordinary skill in the art.

An easily constructed, highly secure, walk-in vault uses pre-cast panels. A door frame is molded into one of the panels. The panels have interlocking joints with adjacent panels. The interlocking joints are protected with continuous, double burglary-proof seams situated in the interior of the vault. Abutting panels are securely held together by metal rods that penetrate the interlocking joints.

BACKGROUND OF THE INVENTION The present invention relates to a disposable applicator, which allows the consumers to sample cosmetic products such as lipsticks, liquid makeups, eye shadows and other types of viscous cosmetics as well as non-cosmetic products such as crayons, prior to making a purchase. Cosmetic retailers do not normally provide "trial-size" samples at the counter. Consequently, when a consumer wishes to sample cosmetic products, the retailers usually offer her full-size items that have been previously sampled by other customers. Due to hygienic reasons the consumer may not want to apply the previously used cosmetics directly on herself. In the case of lipsticks, the consumer usually applies the lipstick to her hand and tries to imagine how the sample would look on her lips. Also, consumer protection and health regulations have been enacted in at least one state which ban shared testers and require retailers and cosmetic companies to provide customers with disposable makeup applicators or samples, or post warning signs and safety instructions. In response, manufacturers have introduced cosmetic samples to be provided to customers in encapsulated blisters. For lipsticks, customers may apply this type of samples to their lips with cotton swabs. This is a less satisfactory solution. At the present time, there is no disposable applicator that allows the consumers to extract lipstick at the retail counters. Other types of applicators are known, e.g., U.S. Pat. No. 5,301,697 to Gueret discloses a disposable applicator having the cosmetics pre-applied to it at the factory under high temperature and pressure conditions; U.S. Pat. No. 5,040,914 to Fitjer discloses a permanent plastic applicator that is porous and sponge-like; U.S. Pat. No. 4,955,745 also discloses a soft porous applicator for applying nail polish; and U.S. Pat. No. 4,050,826 discloses a permanent applicator that allows viscous fluid to pass through via capillary action. Thus, there remains an unresolved need in the cosmetic industry for a disposable applicator which is capable of extracting an amount of cosmetics, e.g., lipsticks, sufficient for a single use. Additionally, the applicator would be stored "dry", i.e., without cosmetics, so that the consumer can extract different types or colors of cosmetics with the applicator at the retail counter prior to sampling. SUMMARY OF THE INVENTION The present invention provides a cosmetic applicator comprising a body member made out of a porous material and having sufficient stiffness to withstand a pressure exerted by an user, wherein the user can extract an amount of cosmetic sufficient for a single use with the applicator. Preferably, in the case of lipsticks, the applicator has a generally cylindrical shape with at least one round or blunt end, or having a beveled surface at one end. The applicator can also be hollow, wherein the cosmetic is deposited within the hollow applicator and is pushed through the top portion of the body member. The present invention also provides methods for sampling cosmetic comprising the steps of (i) extracting an amount of cosmetic sufficient for a single use with a disposable porous applicator; and (ii) applying the cosmetic to the body of a consumer, wherein the cosmetic is extracted immediately prior to sampling the cosmetic. Therefore, an object of the present invention is to provide a hygienic cosmetic applicator for consumer sampling. Another object of the present invention is to provide a hygienic cosmetic applicator that carries an amount of cosmetic sufficient for a single use. Another object of the present invention is to provide a disposable applicator that can be used by the consumer to extract cosmetic samples at the retail counter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a cross-sectional view of a lipstick applicator according to the present invention; FIG. 1B is a cross-sectional view of an alternative embodiment of the lipstick applicator according to the present invention; FIG. 2 is a cross-sectional view of a premeasured amount of lipstick in a disposable container; FIG. 3 is a cross-sectional view of the lipstick applicator of the present invention being used in conjunction with the disposable container shown in FIG. 2; FIG. 4 is a cross-sectional view of the lipstick applicator of the present invention being used in conjunction with a permanent lipstick dispenser; FIG. 5A is a cross-sectional view of a hollow lipstick applicator according to the present invention; FIG. 5B is a cross-sectional view of another alternative embodiment of a hollow applicator according to the present invention; and FIG. 6 is a cross-sectional view of a hollow applicator as shown in either FIGS. 5A and B being used with a further alternative embodiment of permanent lipstick dispenser. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The cosmetic applicator of the present invention can be used with a number of cosmetics, i.e., lipsticks, liquid makeups, eye shadows, lip balms, etc. For simplicity lipstick will be used when describing the present invention, but it will be noted that the present invention is not restricted to only lipstick. Now referring to the Figures, wherein like numerals are used to designate like parts and according to FIG. 1, applicator 10 is depicted in FIG. 1A as having a shape that resembles that of a tube of lipstick. Applicator 10 is substantially rigid and is made out of porous polyethylene or other suitable materials that are capable of holding its shape. Applicator 10 should have sufficient stiffness to resist bending or other types of deformation when used by the consumer. Applicator 10 comprises body portion 12 and base portion 14. Body portion 12 has a beveled surface 16. Beveled surface 16 is provided at the top of body portion 12 to facilitate the application of the lipstick stored on the applicator onto the lips. However, the top portion of bullet portion 12 may have other convenient shapes, e.g., round as shown in FIG. 1B or conical shape. It will be noted that surface 16 may also have either concave or convex curvature. Preferably, the tip of body portion 12 resembles the tip of a non-sample tube of lipstick. The disposable applicator 10 of the present invention can be made with sintered polyethylene. In this process, granules of polyethylene are poured into a mold which has the desired lipstick tube shape. The granules are then compressed lightly and heat is added to bond the granules together to form solid applicator 10. It will be noted that in this process the granules are bonded but not melted. Applicator made with sintered polyethylene are porous having pores substantially the size of the polyethylene granules. Such pores are also interconnected in a way that lipstick would be able to flow from one pore to the next. As stated above, it is desirable that the applicator can withstand the pressure exerted by the consumers during the extraction and application. The stiffness of the applicator is determined by the grain size of the polyethylene granules and the overall dimensions of the applicator. Thus, by varying the grain size and the dimensions of applicator 10, the desired stiffness as explained above can be achieved. The grain size also controls the texture of applicator 10. The smaller the grain size the smoother the surface of applicator 10 would feel to the user. Smaller grain size can also aid in the product delivery. When grain size is small, the lipstick that are stored within the pores can be drawn out and be applied to the user due to capillary action. Applicator 10 can be made out of other materials such as styrofoam and other processes such as extrusion, molding, die casting, etc. Thus, the example given above is only to illustrate, and not to limit, the present invention. Applicator 10 may be used to extract a pre-measured amount of lipstick as shown in FIGS. 2 and 3. The lipstick is contained in capsule 20, where an amount of lipstick sufficient for one use is stored within. Capsule 20 is covered by lid 22, which is made out of a thin flexible material such as foil or plastics. Lid 22 is attached to capsule 20 by thermal methods or by adhesives. Capsule 20 can be manufactured on sheets or "blister" packs containing a large number of lipstick capsules. The individual capsule may be separated from each other by perforations for easy separation. The lidding material may be peeled back or punctured to expose the lipstick and applicator 10 is inserted into capsule 20 to extract the lipstick. The consumer simply exerts a slight pressure on the lipstick. Such pressure forces some of the lipstick to enter the porous area and leaves a layer of lipstick on the surface of the applicator. After the lipstick is transferred to the applicator, the consumer can apply the lipstick to her lips. Frictional contact between the applicator and the lips deposits a film or thin layer of lipstick on the lips. Further, due to the capillary action of the lipstick inside the pores, some of the lipstick stored in the pores of applicator 10 will also be applied to the lips. The used applicator may be discarded after one use. Lipstick sampling in accordance with the present invention therefore provides an inexpensive, realistic and hygienic method of sampling lipsticks for the consumers. Blister packs of capsules 20 can be manufactured to contain many different shades, colors and textures of lipsticks. The consumer will be able to apply the lipsticks directly on her lips for sampling with the actual lipstick, and will not have to apply lipsticks to her hand and resort to her imagination with regard to appearance. In another embodiment depicted in FIG. 4, applicator 10 can also be used in conjunction with bulk sources of lipsticks. As shown, a permanent well 24 having storage portion 26 and flat portion 28 is provided. Storage portion 26 is in communication with a bulk source of lipstick L contained within dispensing unit 30 through an aperture 32 defined at the bottom of storage portion 26. Well 24 is attached to dispensing unit 30 in such a way that when bulk source L is pressurized, lipstick will flow from bulk source L through aperture 32. The amount of lipstick dispensed may be measured by several methods. For examples, it can be measured by applying a known pressure to bulk source L for a fixed time period. The pressure can be produced by a simple electrical motor driving a piston acting on dispensing unit 30, or the piston can be pushed by the consumer. The pressure can also be provided by a distensible bladder disposed inside bulk source L and connected to a source of compressed inert gas, such as air, nitrogen or carbon dioxide. The lipstick can also be dispensed in premeasured volumes with devices such as calibration markings on dispensing unit 30 and a piston linearly advancing from one marking to the next. Lipstick can also be dispensed by a pusher rotationally and threadedly attached to a bottom of dispensing unit 30 such that by rotating the pusher one revolution a known volume of lipstick is released. The lipstick dispensed can be measured by the number of revolutions turned. The pusher may be rotated by hand or by an electrical motor. Alternatively, the bulk source inside dispensing unit 30 may be contained in a disposable bag, and a pressure source as described above may be applied directly to the bag to dispense lipstick. An advantage of using the disposable bag is the relative ease in replacing the bulk lipstick once it is empty. The retailer can simply discard the empty bag and insert a new bag. For example, the disposable bag may be used in conjunction with the distensible bladder contained within the bag. As the distensible bladder is expanded within the bag, lipstick is dispensed. When the bladder has expanded to substantially the same size as the bag, most of the lipstick would have been dispensed. Well 24 should be securely attached to dispensing unit 30. As shown in FIG. 4, flat portion 28 is shown to be connected to the walls of dispensing unit 30. Flat portion 28 may have threaded channel to receive a threaded top portion of the walls of dispensing unit 30. With the threaded connection, well 24 can easily be removed for cleaning or replacement. It is also desirable for the purpose of cleaning to minimize the outer area of well 24 that contacts lipstick. For this purpose there is provided a seal 34 disposed above but approximate aperture 32. This seal will prevent lipstick from bulk source L from advancing far beyond aperture 32. Thus, well 24 can be easily cleaned after it is removed from dispensing unit 30. It will be noted that FIGS. 2-4 depict a well with a round nose applicator 10. However, well 24 and capsule 20 may also have shapes that would accommodate beveled surface 16 or the other shapes described above. So long as the applicator has sufficient stiffness to resist the force exerted by the consumer, it may have a hollow construction as shown in. FIGS. 5A and 5B. Hollow applicator 40 may be used with well 24 and capsule 20 as shown in FIGS. 2-4. Hollow applicator 40 can also be used in conjunction with another dispensing unit as shown in FIG. 6. In another alternative embodiment, an elongated member 42 with a channel 44 defined longitudinally therein is provided as shown in FIG. 6. Channel 44 is in communication with a bulk source of lipstick such that lipstick can be dispensed through channel 44 by pressure sources described above. When a consumer wishes to sample a particular shade or color of lipstick, she simply places hollow applicator 40 over the elongated member 42 so that hollow applicator 40 snugly covers elongated member 42 as shown in FIG. 6. A sealing member 46 is provided to keep the dispensed lipstick within the vicinity of the top of porous applicator 40. The pressure applied to the bulk source will also drive the dispensed lipstick through the interconnected pores of the applicator to the top portion of hollow applicator 40. In this embodiment, when the lipstick reaches the outer surface of applicator 40, a sufficient amount of lipstick has been dispensed. Thus, the amount of lipstick dispensed can also be controlled by visual inspection. While various embodiments of the present invention are described above, it is understood that various features of the preferred embodiments can be used singly or in any combination thereof. Thus the present invention will not be limited to only the specifically embodiments depicted herein.

The present invention provides a disposable applicator for sampling cosmetics including lipsticks at the retail counters. Also provided are methods for extracting or otherwise transferring the cosmetics onto the applicator and sampling the cosmetics.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to provisional U.S. Patent Application Ser. No. 62/043,615 filed on Aug. 29, 2014, the application of which is incorporated herein by reference in its entirety. FEDERAL SPONSORSHIP Not Applicable JOINT RESEARCH AGREEMENT Not Applicable TECHNICAL FIELD This invention pertains generally to food containers and food dispensing trays. More particularly, the invention pertains to a food tray that may be used to more efficiently and quickly dispense food in uniform quantities while providing a tray assembly that is easily cleaned and stackable for storage. BACKGROUND Over the years various food containers have been devised to display food in an attractive manner while also providing a functional vessel to dispense food. At times it may be desirable to elevate the container to provide a heat source under the container while aesthetically displaying food within the container. A wire frame may be utilized to elevate the container a desired distance above the heat source. The container may be modified to couple in mating relation with the wire frame. At times, serving food from the container may require a separate ladle, however scooping food from the container may lead to inconsistent serving sizes and may also result in unintentional spills. Alternatively, containers with spouts have been devised, however when multiple containers are stacked for stowage, the containers require additional height to accommodate stacked containers. SUMMARY Embodiments according to aspects of the invention provide a food tray usable during the food production, display and dispensing of food product. Without limitation intended, the food tray of the present invention is particularly useful when making, displaying and dispensing mini donuts. The tray of the present invention includes a removable ramp that provides for efficient dispensing of food products into smaller point of sale containers including, for example, bags or buckets. In accordance with aspects of the invention, an embodiment of the food dispensing tray assembly includes a tray and a removable ramp. Additionally, the assembly may include a wire frame stand or support to elevate the tray above a working surface. The tray includes a bottom, sides extending upward from the bottom and a lip extending outward from an upper end of the sides around a perimeter of an open top of the tray. Also, a cutout is formed in the tray to define a discontinuity in the lip and to provide an opening in a side of the tray for the ramp to couple to the tray. The removable ramp has a base, angled sides extending from edges of the base, interlocking rims that lock with an upper edge of the lip of the tray, and flanges extending between the base and the rim that engage inner walls of the tray adjacent the cutout in the side of the tray. A separation distance between the sides of the ramp is slightly less than a width of the cutout formed in the tray such that the ramp couples to the tray within the cutout in a mating relationship. A support extending outwardly from a bottom of the base of the ramp includes a groove in the support that engages a lower edge of the cutout of the tray. Additionally, in accordance with aspects of the invention the food dispensing tray assembly may include a tray, removable ramp, and support. The tray includes a bottom, sides extending upward from the bottom and a lip extending outward from an upper end of the sides around a perimeter of an open top of the tray, wherein a cutout is formed in the tray defining a discontinuity in the lip. The removable ramp has a base, angled sides extending from edges of the base, interlocking rims that lock with an upper edge of the lip of the tray, and flanges extending between the base and the rim that engage inner walls of the tray adjacent the cutout in the side of the tray. A separation distance between the sides of the ramp is slightly less than a width of the cutout formed in the tray to provide a desired fit between the ramp and tray. A support extending outwardly from a bottom of the base of the ramp includes a groove in the support that engages a lower edge of the cutout of the tray. A wire frame or stand may be further incorporated into the assembly to elevate the tray and ramp above a working surface. The accompanying drawings, which are incorporated in and constitute a portion of this specification, illustrate embodiments of the invention and, together with the detailed description, serve to further explain the invention. The embodiments illustrated herein are presently preferred; however, it should be understood, that the invention is not limited to the precise arrangements and instrumentalities shown. For a fuller understanding of the nature and advantages of the invention, reference should be made to the detailed description in conjunction with the accompanying drawings. DESCRIPTION OF THE DRAWINGS In the various figures, which are not necessarily drawn to scale, like numerals throughout the figures identify substantially similar components. FIG. 1 is an exploded perspective view of a tray and ramp in accordance with an embodiment of the invention elevated above a wire frame; FIG. 2 is a perspective view of the ramp elevated above the tray and having the ramp removed in accordance with an embodiment of the invention; FIG. 3 is a bottom end perspective view of the tray illustrating the cutout and having the ramp or chute removed; FIG. 4 is a front right perspective view of the ramp in accordance with an embodiment of the invention; FIG. 5 is a front left perspective view of the ramp of the type shown in FIG. 4 and in accordance with an embodiment of the invention; FIG. 6 is a back perspective view of the ramp of the type shown in FIG. 4 ; and FIG. 7 is a bottom back perspective view of the ramp of the type shown in FIG. 4 . DETAILED DESCRIPTION The following description provides detail of various embodiments of the invention, one or more examples of which are set forth below. Each of these embodiments are provided by way of explanation of the invention, and not intended to be a limitation of the invention. Further, those skilled in the art will appreciate that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. By way of example, those skilled in the art will recognize that features illustrated or described as part of one embodiment, may be used in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention also cover such modifications and variations that come within the scope of the appended claims and their equivalents. A food dispensing tray assembly 10 particularly well suited for point of sale production, display and dispensing of food stuffs, includes a wire stand or frame 14 , tray 16 and detachable ramp or chute 18 . The ramp is particularly well suited to re-direct food stuff from the tray into point of sale bags, buckets, or other point of sale containers. Additionally, the ramp is easily removed to clean the ramp prior to stowage. With reference to FIGS. 1-3 , the tray 16 includes a bottom 28 , discontinuous sides 30 extending upward from the bottom 28 , a lip 34 extending outward from an upper end of the sides 30 . A rim 32 extends downward from an outer end of the lip 34 . The lip 34 extends around a perimeter of an open top of the tray 16 . A cutout or void 38 is formed in an end side of the tray 16 , defining a discontinuity in the sides 30 and lip 34 . The cutout 38 of the tray 16 extends from the lip 34 downward to a curved intersecting portion 40 of the bottom 28 and sides 30 of the tray 16 . The sides 30 of the tray 16 slope outward from the bottom 28 of the tray to reduce the amount of food particles retained on the sides 30 . With reference to FIGS. 4-7 , the removable ramp or food chute 18 includes a base 50 , angled sides 52 extending from edges of the base 50 , and interlocking curved clips or fingers 56 that lock with an upper edge of the lip 34 and rim 32 of the tray 16 . Flanges 54 extend between the base 50 and the clip 56 and is dimensioned to engage an inner side wall of the tray 16 adjacent the cutout 38 in the side 30 of the tray 16 . A separation distance between the sides 52 of the ramp 18 is slightly less than a width of the cutout 38 formed in the tray 16 . A support 58 extends outwardly from a bottom of the base 50 of the ramp 18 , wherein a groove 60 in the support 58 engages a lower edge 42 of the cutout 38 of the tray 16 . The lower edge 42 of the cutout engages in the groove to further retain the ramp 18 in a fixed position relative to the tray. The flange 54 extends from the base 50 forming an angle between the base 50 and the flange 54 , the angle being obtuse. Use of the food dispensing tray assembly 10 will next be described in conjunction with the production, sale and dispensing of mini donuts. Those skilled in the art will appreciate that other food stuffs may be equally dispensed efficiently from the tray 16 of the present invention. During the production of mini donuts a donut machine ejects fried donuts into the tray 16 , where the donuts may be sugared or otherwise coated while they cool. Donuts are easily dispensed from the tray by pushing or sliding the donuts on to ramp 18 . A bag or bucket may be placed under the ramp to collect the desired number of donuts to be sold. When the tray is empty and cleanup is required, the ramp 18 is detached from the lip 34 of the tray 16 and quickly cleaned. Multiple trays 16 may be stacked together and multiple ramps 18 may be stowed in the open tray portion of the upper most tray of stacked trays. These and various other aspects and features of the invention are described with the intent to be illustrative, and not restrictive. This invention has been described herein with detail in order to comply with the patent statutes and to provide those skilled in the art with information needed to apply the novel principles and to construct and use such specialized components as are required. It is to be understood, however, that the invention can be carried out by specifically different constructions, and that various modifications, both as to the construction and operating procedures, can be accomplished without departing from the scope of the invention. Further, in the appended claims, the transitional terms comprising and including are used in the open ended sense in that elements in addition to those enumerated may also be present. Other examples will be apparent to those of skill in the art upon reviewing this document.

A food tray is described that may be used to more easily remove food product from the tray. The device allows for emptying of the tray with the use of a removable ramp or spout that easily cleaned and coupled to the tray.

BACKGROUND OF THE INVENTION [0001] The present invention relates to a method for fabricating a semiconductor device, more specifically to a method for fabricating a semiconductor device comprising gate insulation films having different film thicknesses from each other. [0002] In recent semiconductor devices, gate insulation films have different film thicknesses from each other for improved device characteristics, etc. In DRAM, for example, it is preferable for improved operation speed to form, as the peripheral circuit transistors, transistors having the gate insulation film made thinner. On the other hand, it is preferable that the memory cell transistors have the gate insulation film made thicker than the peripheral circuit transistors, because the memory cell transistors having the gate insulation film made as thin as the peripheral circuit transistors have too low threshold voltage, which deteriorates controllability and refresh characteristics. In non-volatile semiconductor devices, such as EEPROM, flash EEPROM, etc., in addition to the above-described requirement for the peripheral circuit transistors and the memory cell transistors, transistors having the gate insulation film which is thicker than the transistors forming the memory cell transistors and logics of the peripheral circuits are required as high breakdown voltage transistors used in writing/erasing. [0003] Conventional techniques for forming gate insulation films having different film thickness from each other are a technique wherein a silicon oxide film is formed uniformly on an entire surface and removed in a region, and then additionally oxidized to thereby provide a difference in film thickness between the region for the silicon oxide film removed and the rest region, and techniques using enhanced oxidation and retarded oxidation by ion implantation. It is preferable from the viewpoint of throughputs to use the techniques using enhanced oxidation and retarded oxidation by ion implantation. [0004] In the techniques using ion implantation, it has been proposed that nitrogen ions are implanted in a silicon substrate before a gate insulation film is formed to thereby suppress the following oxidation (retarded oxidation), and argon ions are implanted in a silicon substrate before a gate insulation film is formed to thereby enhance the following oxidation (enhanced oxidation). In the specification of laid-open Japanese Patent Application No. Hei 11-260813/1999 and the specification of Japanese Patent No. 2950101, a technique wherein fluorine ions are implanted in a silicon substrate before a gate insulation film is formed to thereby enhance the following oxidation is proposed. Such ion implantation is performed selectively in a specific region, whereby a gate insulation film of silicon oxide film which is thicker or thinner in an ion-implanted region than in the rest region can be formed. [0005] Thus, by the conventional method for fabricating a semiconductor device, wherein the gate insulation film is formed by using the enhanced oxidation or retarded oxidation by ion implantation, the gate insulation films having different film thicknesses from each other can be formed by one thermal oxidation step. [0006] However, the conventional semiconductor device fabrication method using the retarded oxidation by nitrogen ion implantation has often degraded reliability of the gate insulation film. The conventional semiconductor device fabrication method using the enhanced oxidation by argon ion implantation has often increased gate leak current. The conventional semiconductor device fabrication method using argon ion implantation produces a relatively small film thickness difference of about 10% between a region with ions implanted and a region without the ion implantation. A technique for ensuring larger film thickness differences has been required. [0007] Usually, wet oxidation film is more reliable than dry oxidation film, and the oxidation technique for forming a gate insulation film is preferably wet oxidation. However, in a case that the above-described method uses wet oxidation, the effect of the enhanced oxidation by ion implantation is much suppressed, and the merit of the ion implantation has not been produced. Accordingly, dry oxidation has been used for the oxidation for the enhanced oxidation, and the gate insulation film of high quality which is comparable to that of the wet oxidation film has not been produced. SUMMARY OF THE INVENTION [0008] An object of the present invention is to provide a semiconductor device fabrication method which can form gate insulation films having different film thicknesses from each other while retaining sufficient reliability and sufficient film thickness difference. [0009] A first method for fabricating a semiconductor device according to the present invention is characterized mainly in that halogen ions are implanted before the thermal oxidation for forming a gate insulation film, and is also characterized in that wet oxidation under low pressure is applied to forming the gate insulation film. [0010] Fluorine, which is one of VII-group elements (halogen), is added to a silicon oxide film in a suitable amount to thereby improve reliability thereof. Accordingly, the oxidation is enhanced by fluorine ion implantation, whereby reliability of the gate insulation film can be improved, and the gate insulation films having different film thicknesses from each other can be formed by one oxidation step. However, as described above, dry oxidation is used for the oxidation for the enhanced oxidation, and no silicon oxide film of good quality which is comparable to wet oxidation film can be formed. [0011] In such circumstances, the inventors of the present application have made earnest studies and found for the first time that wet oxidation under low pressure or in an atmosphere of nitrogen or diluted with rare gas applied to forming a gate insulation film is very effectively for producing the effect of the enhanced oxidation. [0012] The effect of the enhanced oxidation by the ion implantation is conspicuous in dry oxidation but is not in wet oxidation. This will be due to oxidizability difference between the two. That is, wet oxidation, which is more oxidizable than dry oxidation, advances the oxidation reaction so rapidly that an implanted element cannot affect the mechanism. Then, the inventors of the present application had an idea that oxidizability of wet oxidation is reduced so as to delay the oxidation reaction, whereby the enhanced oxidation effect by the ion implantation is allowed to be sufficiently exerted, and tested wet oxidation under low pressure or in an atmosphere of nitrogen or diluted with rare gas. [0013] As a result, wet oxidation film could be formed without much suppressing the effect of the enhanced oxidation by fluorine ion implantation. Especially by suitably controlling conditions for the fluorine ion implantation, silicon oxide film can be made more reliable than that formed without the fluorine ion implantation. [0014] It is preferable that the wet oxidation is conducted in an ambient atmosphere which an H 2 O partial pressure is less than 1 atm. A low pressure oxidation and a dilute oxidation may be applicable to such the wet oxidation. The low pressure wet oxidation used in this specification is wet oxidation made under low pressure, and a pressure in a film forming chamber is set to be, e.g., 1-400 Torr. The same effect can be produced by dilution with nitrogen, rare gas, such as argon, etc., or inactive gas so that an H 2 O partial pressure becomes less than 1 atm to prepare a steam partial pressure equivalent to the low pressure. It is possible that nitrogen, rare gas, such as argon, etc., or inactive gas is used under low pressure so as to use the synergetic effect. The diluent gases are not limited to rare gas or inactive gas. It is possible that oxygen or hydrogen may be also used as diluent gas. These gases have an effect of lowering the oxidation rate. It is possible that other additives, e.g., hydrogen chloride (HCl) may be incorporated in the atmosphere for the end of improving film quality of silicon oxide film, and other ends. [0015] Wet oxidation film of good quality can be formed, producing the effect of the enhanced oxidation by the ion implantation, for example, at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, at a 3 liters oxygen flow rate, at 20 liters nitrogen flow rate, and a 5% hydrogen chloride flow rate. [0016] Then, the first method for fabricating a semiconductor device according to the present invention will be detailed below. [0017] [0017]FIG. 1 is a graph of dose dependency of silicon oxide film thickness of samples each with a silicon oxide film formed by implanting fluorine ions at 5 keV acceleration energy through a 6 nm-thick sacrificial oxidation film and removing the sacrificial oxidation film and forming the silicon oxide film by low pressure wet oxidation or dry oxidation. In FIG. 1, the circles indicate the formation of the silicon oxide film by low pressure wet oxidation, and the squares indicate the formation of the silicon oxide film by dry oxidation. [0018] As shown, both in the low pressure wet oxidation and the dry oxidation, the silicon oxide films increase thickness as the doses are increased. It is found that the enhanced oxidation is caused by the fluorine ions implantation. At below an about 1×10 14 cm −2 dose, the enhanced oxidation is below about 4%, and the effect is not conspicuous. At a 5×10 14 cm −2 dose, a film thickness increase is about 20% for the dry oxidation and about 15% for the low pressure wet oxidation. At a 1×10 15 cm −2 dose, the film thickness is further increased, and a film thickness increase is about 35% for the dry oxidation and about 20% for the low pressure wet oxidation. [0019] [0019]FIG. 2 is a graph of acceleration energy dependency of silicon oxide film thickness of samples each with a silicon oxide film formed by implanting fluorine ions at a 5×10 14 cm −2 dose through a 6 nm-thick sacrificial oxidation film, removing the sacrificial oxidation film and forming the silicon oxide film by low pressure wet oxidation. [0020] As shown, a film thickness of the formed silicon oxide film increases as the acceleration energy increases and decreases when the acceleration energy exceeds about 10 keV. This is because when the acceleration energy is too low, nitrogen is mostly incorporated into the sacrificial oxidation film and cannot contribute to the oxidation reaction, and when the acceleration energy is too high, nitrogen is incorporated deep into a region of the substrate, which does not contribute to the oxidation reaction. Accordingly, it is preferable that conditions for the acceleration energy are selected so that many nitrogen atoms are incorporated into a region of the substrate, which contributes to the oxidation reaction. For example, when nitrogen ions are implanted with the sacrificial oxidation film of an about 6 nm-thick, it is preferable in FIG. 2 that the acceleration energy is set at about 5-10 keV. [0021] From this viewpoint, a film thickness of the sacrificial oxidation film is set to be thinner than a projected range R p of nitrogen ions. Specifically, it is preferable that the acceleration energy of nitrogen ions are set so that a projected range R p of nitrogen ions is positioned at a depth of less than 10 nm from the interface between the sacrificial oxidation film and the silicon substrate. The sacrificial oxidation film is formed for the prevention of the substrate from being contaminated when the ions are implanted. Accordingly, when the ions can be implanted in a clean environment, the sacrificial oxidation film is not essential. [0022] [0022]FIG. 3 is a graph of dose dependency of etching rates of a silicon oxide film with nitrogen ions implanted at 5 keV acceleration energy. The shown etched film thicknesses are equivalent to the etching amounts when the samples are etched by the etching condition of 10 nm-thick thermal oxidation film without nitrogen ions implanted. [0023] As shown, as the dose of nitrogen ions increases, the etching rate of silicon oxide film much increases. The etching step of removing the sacrificial oxidation film is necessary after the nitrogen ion implantation and before the gate insulation film formation. In the etching step, the device isolation film as well as the sacrificial oxidation film is exposed to the etching. Accordingly, unpreferably for device isolation characteristics and surface planarity the device isolation film is etched at the high etching rate shown in FIG. 3. Accordingly, it is preferable that the sacrificial oxidation film is made as thin as possible so as to expose the device isolation film to the etching for a shorter period of time. [0024] [0024]FIG. 4 is a graph of results of damage measured by thermal wave method, which was incorporated in the silicon substrate when fluorine ions are implanted in a 5×10 14 cm −2 dose. As shown, the damage in the substrate increases as the acceleration energy for the fluorine ions is increased. Accordingly, it is preferable from the viewpoint of less damage in the silicon substrate that the acceleration energy is set as low as possible. [0025] [0025]FIG. 5 is a graph of reliability of silicon oxide films of samples measured by constant voltage TDDB (time dependent dielectric breakdown) method, each of which was formed by implanting fluorine ions at 5 keV acceleration energy and forming a 5 nm-thick silicon oxide film by low pressure wet oxidation. In FIG. 5,  mark indicates the sample which fluorine ions are implanted at a dose of 1×10 14 cm −2 , □ mark indicates the sample which fluorine ions are implanted at a dose of 2×10 14 cm −2 , ▪ mark indicates the sample which fluorine ions are implanted at a dose of 5×10 14 cm −2 , and Δ mark indicates the sample which fluorine ions are implanted at a dose of 1×10 15 cm −2 . As a control, the reliability of a wet oxidation film formed without fluorine ion implantation is indicated by ο mark. Oxidation conditions were controlled so that all the samples have a 5 nm-thick for the end of expelling influences due to differences in the film thickness. The MOS capacitor used for the measurement has an N + gate electrode formed on a p-type substrate interposing a silicon oxide film therebetween. [0026] As shown, it is found that as the fluorine dose is increased from 1×10 14 cm −2 to 2×10 14 cm −2 dose and further to 5×10 14 cm −2 , the silicon oxide films have longer lifetimes. However, when the dose is increased to 1×10 15 cm −2 , the lifetime is shortened by about one digit, and the silicon oxide film has poor quality than that of the sample without fluorine ions implanted. A detailed mechanism for implanted fluorine ions making a lifetime of silicon oxide film longer is not clear, but it will be a cause that suitable incorporation of fluorine in the interface between a silicon substrate and silicon oxide film improves interface characteristics. Accordingly, it is preferable that a dose of fluorine ions is set to be not less than 1×10 14 cm −2 and less than 1×10 15 cm −2 . [0027] [0027]FIG. 6 is a graph showing damages in the substrates measured by thermal wave method. The measurements are conducted before and after the silicon oxide film formation. In FIG. 6, ∇ mark indicates the damage incorporated immediately after the implantation, ο mark indicates the damage after the 3 nm-thick silicon oxide film formation by the dry oxidation, □ mark indicates the damage after the 4 nm-thick silicon oxide film formation by the dry oxidation, Δ mark indicates the damage after the 4.5 nm-thick silicon oxide film formation by the low pressure wet oxidation. As shown, the damage incorporated by the fluorine ion implantation has been substantially removed during the formation of the silicon oxide film. Considering that the residual damage in the sample, which the silicon oxide film is formed after the nitrogen ion implantation at the dose of 5×10 14 cm −2 dose, is typically about 2000 [TW unit], the enhanced oxidation by fluorine ion implantation is more effective than that by nitrogen ion implantation. [0028] [0028]FIG. 7 is a graph of fluorine distributions in the silicon substrates before and after the silicon oxide films were formed. FIG. 8 is a graph of fluorine distributions in the silicon oxide films before and after the silicon oxide films were formed. As shown in FIG. 7, by either of the dry oxidation and the low pressure wet oxidation, fluorine concentrations in the silicon substrates are lowered to below the detection limit as the silicon oxide films were formed. On the other hand, as shown in FIG. 8, fluorine remains in the dry oxidation film by about {fraction (1/100)} of the implanted doses, while fluorine remains in the low pressure wet oxidation film by about {fraction (1/1000)} of the implanted doses. Accordingly, the low pressure wet oxidation film is less affected by fluorine in comparison with the dry oxidation film. [0029] The mechanism for fluorine contributing to the enhanced oxidation in the wet oxidation process, and the mechanism for fluorine in the silicon oxide film vanishing are not clear. The inventors of the present invention consider as follows. That is, fluorine contributes to the enhanced oxidation in the wet oxidation process because fluorine atoms bonded with silicon atoms in the interface between the silicon oxide film and the silicon substrate attract electrons, thereby weakening bonds of back bonds of the silicon (FIG. 9A). The mechanism for fluorine in the silicon oxide film vanishing will be that OH − acts on bonding between the silicon and the fluorine in the silicon oxide film to bond the oxygen of the OH − with the silicon while the fluorine bonded with the silicon is evaporated in HF (FIG. 9B to 9 D). [0030] [0030]FIG. 10 is a graph of J-E characteristics of a sample with a silicon oxide film formed by the low pressure wet oxidation after fluorine ions were implanted at 5 keV acceleration energy and at a 5×10 14 cm −2 dose, and J-E characteristics of a sample with a silicon oxide film formed by the low pressure wet oxidation without fluorine ion implantation. FIG. 11 is a graph of high frequency C-V characteristics of a sample with silicon oxide films formed by the low pressure wet oxidation after fluorine ions were implanted at 5 keV acceleration energy and a sample with a silicon oxide film formed by the low pressure wet oxidation without fluorine ion implantation. A MOS capacitor used in the measurement had an N + gate electrode formed on a p-type substrate interposing the silicon oxide film therebetween and had a 0.1 mm 2 electrode area. As shown in FIG. 10, the sample with fluorine ions implanted, and the sample without fluorine ions implanted have substantially equal J-E characteristics. As shown in FIG. 11, the sample with fluorine ions implanted in a 1×10 15 cm −2 dose has the large flat band voltage shift, but the samples with fluorine ions implanted in doses of not more than 5×10 14 cm −2 could have the flat band voltage shifts suppressed small. Thus, it is considered that the fluorine implantation in doses which are less than 1×10 15 cm −2 does not affect the electric characteristics of the silicon oxide film. [0031] As described above, silicon oxide film is formed by the low pressure wet oxidation after fluorine ions are implanted, whereby the silicon oxide film can have higher reliability than wet oxidation film formed without the fluorine ion implantation. In addition, the effect of the enhanced oxidation can be enhanced in comparison with that produced by the conventional method using argon ion implantation. [0032] Iodine (I), which is a halogen element, as is fluorine, has the same properties as fluorine, and has the atomic weight, which is larger than that of fluorine. Iodine ions are used as a dopant to be implanted before the silicon oxide film is formed to produce the same effect described above as produced by implanting fluorine ions, and the enhanced oxidation is more effective than that produced by fluorine ion implantation. [0033] [0033]FIG. 12 is a graph of film thickness differences of silicon oxide films of samples prepared by implanting iodine ions at 10-20 keV acceleration energy and in 0−1×10 15 cm −2 doses through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide films by thermal oxidation. [0034] As shown, by the iodine ion implantation as well as the fluorine ion implantation, the film thicknesses of the silicon oxide films increase as the doses increase. The film thickness increases of the silicon oxide films are much larger in comparison with those by the fluorine ion implantation. At 10 keV acceleration energy, a film thickness increase was about 10% for a 1×10 13 cm −2 dose; about 20-40%, for a 1×10 14 cm −2 dose; about 50-80% for a 3×10 14 cm −2 dose; about 60-120% for a 5×10 14 cm −2 dose; and about 150-240% for a 1×10 15 cm −2 dose. At 20 keV acceleration energy, a film thickness increase was about 30-60% for a 5×10 14 cm −2 dose. The iodine ion implantation as well as the fluorine ion implantation makes the effect of the enhanced oxidation higher in the dry oxidation film than in the low pressure wet oxidation film. In comparison with the fluorine ion implantation, the iodine ion implantation can make the effect of the enhanced oxidation higher also in the low pressure wet oxidation film. [0035] [0035]FIG. 13 is a graph of reliability of silicon oxide films of samples measured by constant voltage TDDB, each of which was formed by implanting iodine ions at 10 keV acceleration energy and forming a 5 nm-thick silicon oxide film by low pressure wet oxidation. In FIG. 13, □ mark indicates the reliability for the silicon oxide film formed at a 1×10 13 cm −2 dose, Δ mark indicates the reliability for the silicon oxide film formed at a 1×10 14 cm −2 dose. As a control, the reliability of a sample without iodine ions implanted is indicated by ο mark. Oxidation conditions were controlled so that all the samples have a 5 nm-thickness for the end of expelling influences due to differences in the film thickness. [0036] As shown, all the samples with iodine ions implanted could have the oxide film lifetimes equal to or longer than the oxide film lifetime of the sample without iodine ions implanted. [0037] As described above, by the iodine ion implantation as well, the effect of the enhanced oxidation can be enhanced without deteriorating film quality of silicon oxide film. Especially by using iodine, a much higher rate of the enhanced oxidation can be obtained in comparison with that obtained by using fluorine. Accordingly, by using iodine, the atmospheric wet oxidation can provide sufficient effect of the enhanced oxidation. [0038] Although the inventors of the present application have not tested, chlorine (Cl) and bromine (Br), which belong to VII group, are expected to produce the same effect. [0039] A second method for fabricating a semiconductor device according to the present invention is characterized mainly in that ions of rare gas, such as xenon (Xe) or krypton (Kr) are implanted before the thermal oxidation for forming the gate insulation film. [0040] Xenon and krypton as well as argon are elements belonging to the rare gas, and are elements having larger atomic weights than argon. Accordingly, it is considered that implanted xenon and krypton are little influential and have higher effect of the enhanced oxidation. From this viewpoint, the inventors of the present invention have made earnest studies and found that xenon ions and krypton ions are used as ion species to be implanted before a silicon oxide film is formed, whereby the effect of the enhanced oxidation can be much enhanced. Especially by using xenon good effect of the enhanced oxidation can be produced not only in the dry oxidation, but also in the low pressure wet oxidation and the atmospheric wet oxidation. By using even argon, which does not produce sufficient effect of the enhanced oxidation in the atmospheric wet oxidation, sufficient effect of the enhanced oxidation could be produced in the low pressure wet oxidation. [0041] [0041]FIG. 14 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films which were formed by implanting xenon ions at 10-20 keV acceleration energy and in 0−5×10 14 cm −2 does through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide film by thermal oxidation. In FIG. 14, ο mark indicates film thickness for the dry oxidation. □ mark indicates film thickness for the low pressure wet oxidation. Δ mark indicates film thickness for the low pressure wet oxidation following annealing at 600° C. [0042] As shown, as the dose increases, the thickness of the silicon oxide films increases. At 10 keV acceleration energy, the film thickness increases by about 4-8% for a 1×10 13 cm −2 dose, by about 10-20% for a 1×10 14 cm −2 dose, by about 30-45% for a 3×10 14 cm −2 dose, and by about 50-60% for a 5×10 14 cm −2 dose. At 20 keV acceleration energy, the increases of the film thickness is a little smaller, and the increase of the film thickness is about 30-50% at a 5×10 14 cm −2 dose. [0043] In comparison between the dry oxidation and the low pressure wet oxidation, the film thickness increase is larger in the dry oxidation, as in the case of using halogen. In the low pressure wet oxidation, however, an about 50% film thickness at maximum could be obtained. [0044] A characteristic of the use of xenon is that the effect of the enhanced oxidation can be produced even with the annealing after the ion implantation and before the oxidation. In the case of the argon ion implantation, the annealing makes the enhanced oxidation less effective. The annealing before the oxidation is effective to recover damage incorporated in a silicon substrate. Accordingly, the silicon oxide film after the annealing, and the silicon substrate can have improved reliability. [0045] It is preferable that a film thickness of the sacrificial oxidation film, and acceleration energy for the ions are set to be the same as those for using halogen. [0046] A third method for fabricating a semiconductor according to the present invention is characterized in that nitrogen ions are implanted before thermal oxidation for forming a gate insulation film, and then using oxidation combining the dry oxidation and the low pressure wet oxidation for forming the gate insulation film. [0047] [0047]FIG. 15 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films which were formed by implanting nitrogen ions (N + ) at 5 keV acceleration energy and in 0−4×10 14 cm −2 does through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide film by the low pressure wet oxidation. [0048] As shown, combining the nitrogen ion implantation and the low pressure wet oxidation, the effects of retarded oxidation can be obtained. However, the film thickness decrease is only about 7% for implanting nitrogen ions at 5 keV acceleration energy and in a 4×10 14 cm −2 dose. In comparison with the dry oxidation which has the film thickness decrease of about 20%, the film thickness decrease in the low pressure wet oxidation is low. [0049] From this viewpoint, the inventors of the present invention have made earnest studies to find the oxidation method which can obtain the effects of the retarded oxidation and the merit of the wet oxidation, and found for the first time that implanting nitrogen ions before forming the gate insulation film by the thermal oxidation and forming the gate insulation film by combining dry oxidation and low pressure wet oxidation is very effectively for producing the effect of the enhanced oxidation. [0050] [0050]FIG. 16 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films formed each by implanting nitrogen ions through a 6 nm-thick sacrificial oxidation film, removing the sacrificial oxidation film and forming the silicon oxide film by various oxidation methods. In FIG. 16, ο mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation at 750° C.  mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation after nitrogen annealing at 600° C. for 1 hour. □ mark indicates a 4 nm-thick silicon oxide film formed by the dry oxidation at 750° C. ▪ mark indicates a 4 nm-thick silicon oxide film formed by the dry oxidation after nitrogen annealing at 600° C. for 1 hour. Δ mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation at 900° C. ∇ mark indicates a sample which is oxidized by the dry oxidation at 750° C. to form a 4 nm-thick silicon oxide film and processed for 30 minutes under a low pressure wet oxidation atmosphere. ▾ mark indicates a sample which is annealed at 1015° C. for 10 seconds in nitrogen atmosphere, oxidized by the dry oxidation at 750° C. to form a 4 nm-thick silicon oxidation film and processed for 30 minutes under a low pressure wet oxidation atmosphere. [0051] As seen in FIG. 16, in forming a 4 nm-thick silicon oxide film by the dry oxidation at 750° C., the oxidation is retarded by about 20% (see the □ marks). The rate of the retarded oxidation can be enhanced to about 30% by the nitrogen annealing before the oxidation, at 600° C. for 1 hour (see the ▪ marks). [0052] In forming the 3 nm-thick silicon oxide film by the dry oxidation (see the ο marks and  marks), the retarded oxidation can be found, but the rate is lower than that for forming the 4 nm-thick silicon oxide film. This will be because the implanted nitrogen do not sufficiently contribute to the oxidation reaction in the oxidation for the 3 nm-thick silicon oxide film. Accordingly, in order to make the retarded oxidation sufficiently effective, it is effective to form silicon oxide film of an above 4 nm-thick. [0053] In forming a silicon oxide film of an about 5.5 nm-total thickness by forming a 4 nm-thick silicon oxide film by the dry oxidation and then processing in a low pressure wet oxidation atmosphere for 30 minutes (see the ▾ marks), the retarded oxidation of about 30% is observed. Especially, under these conditions, the dry oxidation is followed by the wet oxidation, and reliability equal to the wet oxidation film can be obtained. However, when the nitrogen annealing is made at 1015° C. for 10 seconds before the dry oxidation, the effect of the retarded oxidation is not observed. [0054] In comparing between N + ion implantation and N 2 + ion implantation in the retarded oxidation effect, the retarded oxidation effect is higher in the former. This will be because N 2 + has the larger atomic weight than N + and more damages the substrate with a result that the enhanced oxidation effect is exhibited. For nitrogen ion implantation for the purpose of the retarded oxidation the use of N + ions will be effective. [0055] As described above, in order to form silicon oxide film of good quality by the retarded oxidation using nitrogen ions, it is effective to perform the oxidation combining the dry oxidation and the low pressure wet oxidation after nitrogen ions are implanted. [0056] In a fourth method for fabricating a semiconductor device according to the present invention, in place of the ion implantation in the above-described first method for fabricating the semiconductor device, a semiconductor substrate with a sacrificial oxidation film formed on is exposed to a plasma atmosphere containing a halogen element to incorporate the halogen element in the semiconductor substrate. [0057] The present method is the same as the methods using the ion implantation in that an element is incorporated for the purpose of enhancing the enhanced oxidation, and the effect produced by the present method is the same as that produced by the above-described first method for fabricating the semiconductor device. [0058] As a method for incorporating a halogen element by using plasma, for example, a gas, as of F 2 , ArF, KrF, XeF, Cl 2 , ArCl, KrCl, XeCl, Br 2 , ArBr, KrBr, XeBr, I 2 , ArI, KrI, XeI, or others, is incorporated in a vacuum system for magnetron plasma processing. [0059] For example, a halogen element can be incorporated in a silicon substrate by introducing one of these gases into a vacuum system, applying a substrate bias to the back side of the silicon substrate under a 0.01-10 Pa to establish a negative voltage within 1 kV, concurrently therewith introducing electromagnetic waves of 200-2000 W of rf (e.g. 13.56 MHz) or microwaves to parallel plate electrodes to cause discharges and expose the substrate to the plasma for about 10 seconds—about 3 minutes. In place of applying rf or microwaves, electron beams may be applied to ionize a halogen element to apply the halogen ions to the silicon substrate. An ion source, such as ECR, is used to apply ionized halogen ions to the silicon substrate. [0060] A distribution of a halogen element in the silicon substrate can be controlled by gas partial pressure control, discharge voltage control, and a thickness of a protection film on the surface of a silicon substrate. By controlling these parameters, a concentration of the surface of the silicon substrate can be changed to about 1×10 19 cm −2 -10 22 cm −2 . [0061] A halogen element is distributed, decreasing a concentration from the surface of the substrate toward the inside thereof. A distribution width is about 5-10 nm and is about 20-30 nm at maximum. [0062] In exposing the silicon substrate to the plasma, it is important to cover the surface of the silicon substrate with a protection film, and an about 5-10 nm thick silicon oxide film, for example, is formed. In setting high a concentration of halogen to be incorporated, a material of the protection film may be changed corresponding to a gas to be used. [0063] If necessary, a gas, such as a rare gas, may be added to the halogen gas to prepare a mixed gas. [0064] The above-described object is achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or argon into a first region of a silicon substrate; and wet oxidizing the silicon substrate in an ambient atmosphere which an H2O partial pressure is less than 1 atm to thereby form a first silicon oxide film in the first region of the silicon substrate, and a second silicon oxide film thinner than the first silicon oxide film in a second region of the silicon substrate different from the first region. [0065] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing iodine, krypton or xenon into a first region of a silicon substrate; and oxidizing the silicon substrate to thereby form a first silicon oxide film in the first region, and a second silicon oxide film thinner than the first silicon oxide film in a second region of the silicon substrate different from the first region. [0066] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing nitrogen into a first region of a silicon substrate; and wet oxidizing the silicon substrate after dry oxidation to thereby form a first silicon oxide film in the first region, and a second silicon oxide film thicker than the first silicon oxide film in a second region of the silicon substrate different from the first region. [0067] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or a rare gas at a first concentration into a first region of a silicon substrate; selectively introducing a halogen element or a rare gas at a second concentration higher than the first concentration into a second region of the silicon substrate different from the first region; and wet-oxidizing the silicon substrate to thereby form a first silicon oxide film in the first region, a second silicon oxide film thicker than the first silicon oxide film in the second region, and a third silicon oxide film thinner than the first silicon oxide film in a third region of the silicon substrate different from the first region and the second region. [0068] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or a rare gas into a first region of a silicon substrate; selectively introducing nitrogen in a second region of the silicon substrate different from the first region; and wet-oxidizing the silicon substrate after dry oxidation to thereby form a first silicon oxide film in the first region, a second silicon oxide film thinner than the first silicon oxide film in the second region, and a third silicon oxide film thinner than the first silicon oxide film and thicker than the second silicon oxide film in a third region of the silicon substrate different from the first region and the second region. BRIEF DESCRIPTION OF THE DRAWINGS [0069] [0069]FIG. 1 is a graph of relationships between doses of fluorine ions and enhanced oxidation film thickness. [0070] [0070]FIG. 2 is a graph of relationship between acceleration energy of fluorine ions and enhanced oxidation film thickness. [0071] [0071]FIG. 3 is a graph of dose dependency of etching rates of silicon oxide film with nitrogen ions implanted. [0072] [0072]FIG. 4 is a graph of relationships between acceleration energy of fluorine ions and damage incorporated in the silicon substrate. [0073] [0073]FIG. 5 is a graph of relationship between doses of fluorine ions and the silicon oxide film reliability. [0074] [0074]FIG. 6 is a graph of relationship between doses of fluorine ions and damage in the silicon substrates before and after silicon oxide films were formed. [0075] [0075]FIG. 7 is a graph of fluorine distributions in the silicon substrates before and after the silicon oxide films were formed. [0076] [0076]FIG. 8 is a graph of fluorine distributions in the silicon oxide films after the silicon oxide films were formed. [0077] FIGS. 9 A- 9 D are views showing the mechanism for fluorine contributing to the enhanced oxidation in the wet oxidation process, and the mechanism for fluorine in the silicon oxide film vanishing. [0078] [0078]FIG. 10 is a graph of J-E characteristics of silicon oxide films formed after fluorine ion implantation. [0079] [0079]FIG. 11 is a graph of high frequency C-V characteristics of silicon oxide films formed after fluorine ion implantation. [0080] [0080]FIG. 12 is a graph of relationships between iodine ion doses and acceleration energy, and enhanced oxidation film thickness. [0081] [0081]FIG. 13 is a graph of relationships between iodine ion doses and the silicon oxide film reliability. [0082] [0082]FIG. 14 is a graph of relationships between xenon ion doses and acceleration energy, and enhanced oxidation film thickness. [0083] [0083]FIG. 15 is a graph of relationships between nitrogen ion doses and retarded oxidation film thickness. [0084] [0084]FIG. 16 is a graph of oxidation method dependency of retarded oxidation film thickness formed by thermal oxidation following nitrogen ion implantation. [0085] FIGS. 17 A- 17 D and 18 A- 18 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a first embodiment of the present invention, which show the method. [0086] FIGS. 19 A- 19 C and 20 A- 20 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a second embodiment of the present invention, which show the method. [0087] FIGS. 21 A- 21 C and 22 A- 22 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a third embodiment of the present invention, which show the method. [0088] FIGS. 23 A- 23 C and 24 A- 24 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a fourth embodiment of the present invention, which show the method. [0089] FIGS. 25 A- 25 D are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a fifth embodiment of the present invention, which show the method. DETAILED DESCRIPTION OF THE INVENTION [0090] A First Embodiment [0091] A method for fabricating the semiconductor device according to a first embodiment of the present invention will be explained with reference to FIGS. 17 A- 17 D and 18 A- 18 C. [0092] FIGS. 17 A- 17 D and 18 A- 18 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method. [0093] A device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines a device region 14 and a device region 16 (FIG. 17A). In the present embodiment, the device region 14 is a region where a thick gate insulation film is to be formed, and the device region 16 is a region where a thin gate insulation film is formed. In a DRAM, for example, the device region 14 can be a memory cell region and the device region 16 can be a peripheral circuit region. [0094] Then, a sacrificial oxidation film 18 is formed, by thermal oxidation, of, e.g., an about 6 nm-thick silicon oxide film on the device regions 14 , 16 defined by the device isolation film 12 (FIG. 17B). [0095] Next, a photoresist film 20 exposing the device region 14 and covering the device region 16 is formed by the usual photolithography techniques. [0096] Then, fluorine ions are implanted in the silicon substrate 10 with the photoresist film 20 as a mask. The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 17C). [0097] Next, after the photoresist film 20 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. After the sacrificial oxidation film 18 is removed, chemical oxide film may be formed on the surface of the substrate 10 by processing using a chemical liquid, such as SC- 1 , SC- 2 or others. [0098] Then, the silicon substrate 10 is thermally oxidized by low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 and a gate insulation film 24 of silicon oxide film on the device region 16 . At this time, the enhanced oxidation takes place in the device region 14 , where fluorine ions have been incorporated in. Accordingly, the gate insulation film 22 is formed thick in the device region 14 , and in the device region 16 , the gate insulation film 24 is formed thin (FIG. 17D). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine ions implanted set at 4.5 nm, the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.1 nm-thick, and the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited. [0099] Next, annealing is performed at 900° C. for 30 minutes to incorporate the nitrogen into the interface between the gate insulation films 22 , 24 and the silicon substrate 10 , whereby the gate insulation films 22 , 24 are formed of silicon oxynitride film. An annealing temperature may be a temperature suitable to incorporate the nitrogen into the interface and can be typically 700-1100° C. [0100] It is preferable from the viewpoint of improving reliability of the gate insulation films to form the gate insulation films of the silicon oxynitride film. Because fluorine enhances diffusion of boron, the gate insulation films 22 , 24 are formed of silicon oxynitride film, whereby the effect of suppressing increase of gate resistance and source/drain resistance of P-type transistors can be produced. In the method for fabricating the semiconductor device according to the present embodiment, wherein fluorine ions are implanted for the purpose of the enhanced oxidation, it is preferable from the viewpoint of suppressing diffusion of boron to form the gate insulation films 22 , 24 of silicon oxynitride film. [0101] Gate electrodes 26 are formed on the gate insulation films 22 , 24 . Polycrystalline silicon film and tungsten silicide film are deposited by, e.g., CVD method and then are patterned by the usual photolithography and etching to form the gate electrodes 26 of the polycide structure of the layer film of the polycrystalline silicon film and the tungsten silicide film. [0102] Next, ions are implanted in the device regions 14 , 16 with the gate electrodes 26 as a mask to form a source/drain diffused layer 28 for memory cell transistors in the device region 14 and an extension region 30 of the source/drain diffused layer for peripheral circuit transistors in the device region 16 (FIG. 18A). For example, in the n-type transistor forming region, arsenic (As) ions are implanted at 10 keV acceleration energy and a 5×10 14 cm −2 , and, in the p-type transistor forming region, BF 2 ions are implanted at 10 keV acceleration energy 5×10 14 cm −2 . [0103] Next, silicon oxide film is deposited on the entire surface by, e.g., CVD method, and then etched back to form a sidewall insulation film 32 on the side walls of the gate electrodes 26 (FIG. 18B). [0104] Then, ions are implantation in the device region 16 with the gate electrodes 26 and the sidewall insulation film 32 as a mask to form the source/drain diffused layer 34 for the peripheral circuit transistors. For example, in the n-type transistor forming region, arsenic ions are implanted at 50 keV acceleration energy and 3×10 15 cm −2 dose, and in the p-type transistor forming region, BF 2 ions are implanted at 40 keV acceleration energy and 3×10 15 cm −2 dose. [0105] Thus, the memory cell transistors having the thin gate insulation film 22 are formed in the device region 14 , and the peripheral circuit transistors having the thick gate insulation film are formed in the device region 16 (FIG. 18C). [0106] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is made after fluorine ions have been selectively implanted, whereby the gate insulation film in the region where the fluorine ions have been implanted can be made selectively thicker. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have improved reliability than those formed by the dry oxidation. [0107] In the present embodiment, an ion species for enhancing the oxidation is fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, or xenon ions may be used. [0108] Iodine ions are implanted, e.g., at 10 keV acceleration energy and 5×10 14 cm −2 dose to form the gate insulation film 22 of an about 7.8 nm-thick silicon oxide film in the device region 14 and the gate insulation film 24 of an about 4.5 nm-thick silicon oxide film in the device region 16 (see FIG. 12). [0109] Xenon ions are implanted, e.g., at 10 keV acceleration energy and 5×10 14 cm −2 dose to form the gate insulation film 22 of an about 6.5 nm-thick silicon oxide film in the device region 14 and the gate insulation film 24 of an about 4.5 nm-thick silicon oxide film in the device region 16 (see FIG. 14). In the case that xenon ion are used, annealing of, e.g., 600° C. for 1 hour may be performed before the oxidation. [0110] Fluorine ions may be implanted together with other ions, such as iodine ions, xenon ions, krypton (Kr) ions, argon ions, germanium (Ge) ions, silicon ions, etc., whereby the effect of the enhanced oxidation can be further enhanced. Fluorine, which has the effect of improving reliability of the insulation films, is implanted together with such ions to thereby more improve damage in the substrate than singly implanted. [0111] A Second Embodiment [0112] The method for fabricating the semiconductor device according to a second embodiment of the present invention will be explained with reference to FIGS. 19 A- 19 C and 20 A- 20 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first embodiment are represented by the same reference numbers not to repeat or simplify their explanation. [0113] FIGS. 19 A- 19 C and 20 A- 20 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the second embodiment of the present invention, which show the method. [0114] A device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines a device region 36 , a device region 14 and a device region 16 (FIG. 19A). In the present embodiment, the device region 14 is a region where a thick gate insulation film is to be formed, the device region 16 is a region where a thin gate insulation film is to be formed, and the device region 36 is a region where a gate insulation film thinner than the gate insulation film in the device region 14 but thicker than the gate insulation film in the device region 16 is to be formed. In a DRAM, for example, the device region 14 can a memory cell region, the device region 16 can be a peripheral circuit region, and the device region 36 can be a region for high breakdown voltage transistors, such as input/output transistors, etc. to be formed in. [0115] Then, a sacrificial oxidation film 18 is formed, by thermal oxidation, of, e.g., an about 6 nm-thick silicon oxide film on the device regions 14 , 16 , 36 defined by the device isolation film 12 (FIG. 19B) [0116] Next, a photoresist film 38 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography. [0117] Then, fluorine ions are implanted in the silicon substrate 10 with the photoresist film 38 as a mask. The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 4×10 14 cm −2 dose (FIG. 19C). [0118] Next, after the photoresist film 38 is removed, a photoresist film 40 exposing the device regions 36 , 14 and covering the device region 16 is formed by the usual photolithography. [0119] Then, with the photoresist film 40 as a mask, fluorine ions are implanted in the silicon substrate 10 . Fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 1×10 14 cm −2 dose (FIG. 20A). [0120] The twice ion implantation incorporates a 5×10 14 cm −2 dose of fluorine in the device region 36 and a 1×10 14 cm −2 dose of fluorine in the device region 14 . [0121] Next, the photoresist film 40 is removed, and then the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. [0122] Then, the silicon substrate 10 is thermally oxidized by low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 , a gate insulation film 24 of the silicon oxide film on the device region 16 , and a gate insulation film 42 of the silicon oxide film on the device region 36 . At this time, the enhanced oxidation takes place in the device regions 36 , 14 , where fluorine ions have been incorporated in. The enhanced oxidation is more enhanced in the device region 36 , where more fluorine ions are incorporated than in the device region 14 . Accordingly, the thick gate insulation film 42 is formed in the device region 36 , the thin gate insulation film 24 is formed in the device region 16 , and the gate insulation film 22 having the thickness thinner than the gate insulation film 42 but thicker than the gate insulation film 24 is formed in the device region 14 (FIG. 20B). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 5.1 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 4.7 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited. [0123] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 20C). [0124] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is performed after fluorine ions are selective implanted, whereby the gate insulation films in the regions with the fluorine ions implanted can be thick. Different doses of fluorine ions are implanted in the regions, whereby the gate insulation films can be different in thickness among the regions. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have improved reliability than that formed by the dry oxidation. [0125] In the present embodiment, an ion species for enhancing the enhanced oxidation is provided by fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, etc., or xenon ions may be used. [0126] In the present embodiment, three gate insulation films which have different thicknesses from each other are formed, but four or more gate insulation films having different thicknesses from one another may be formed. [0127] A Third Embodiment [0128] The method for fabricating the semiconductor device according to a third embodiment of the present invention will be explained with reference to FIGS. 21 A- 21 C and 22 A- 22 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first and the second embodiments are represented by the same reference numbers not to repeat or to simplify their explanation, [0129] FIGS. 21 A- 21 C and 22 A- 22 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method. [0130] First a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 36 , 14 , 16 (FIG. 21A). [0131] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is formed on the device regions 14 , 16 , 36 defined by the device isolation film 12 (FIG. 21B). [0132] Next, a photoresist film 46 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography. [0133] Then, with the photoresist film 46 as a mask, xenon ions are implanted in the silicon substrate 10 . The xenon ions are implanted, e.g., at 10 keV acceleration energy and a 5×10 14 cm −3 dose (FIG. 21C). [0134] Next, after the photoresist film 46 is removed, a photoresist film 48 exposing the device region 14 and covering the device regions 16 , 36 is formed by the usual photolithography. [0135] Then, with the photoresist film 48 as a mask, fluorine ions are implanted in the silicon substrate 10 . Fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 22A). [0136] Next, after the photoresist film 48 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. [0137] Then, the silicon substrate 10 is thermally oxidized by the low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 , a gate insulation film 24 of the silicon oxide film on the device region 16 and a gate insulation film 42 of the silicon oxide film on the device region 36 . At this time, xenon ions are implanted in the device region 36 , and fluorine ions are implanted in the device region 14 , and the enhanced oxidation takes place in the device regions 36 , 14 . The enhanced oxidation is more enhanced in the device region 36 than in the device region 14 , whereby the gate insulation film 42 in the device region 36 is formed thick, the gate insulation film 24 in the device region 16 is formed thin, and the gate insulation film 22 in the device region 14 is formed thinner than the gate insulation film 42 but thicker than the gate insulation film 24 (FIG. 22B). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine or xenon ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 6.5 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.1 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited. [0138] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 22C). [0139] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is performed after xenon ions and fluorine ions are selectively implanted, whereby film thicknesses of the gate insulation films in the regions with the ions implanted can be selectively increased. Xenon ions and fluorine ions, which are different in the enhanced oxidation effect, are implanted in the different regions, whereby film thicknesses of the enhanced oxidation films in the regions can be made different from one another. The gate insulation films, which are formed by the wet oxidation, can have improved reliability than those formed by the dry oxidation. [0140] In the present embodiment, an ion species for enhancing the enhanced oxidation is provided by fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, may be used. [0141] In the present embodiment, the gate insulation films of three different film thicknesses are formed, but the gate insulation film of four or more different film thicknesses may be formed. [0142] A Fourth Embodiment [0143] The method for fabricating the semiconductor device according to a fourth embodiment of the present invention will be explained with reference to FIGS. 23 A- 23 C and 24 A- 24 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first to the third embodiments are represented by the same reference numbers not to repeat or to simplify their explanation. [0144] FIGS. 23 A- 23 C and 24 A- 24 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method. [0145] First, a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 36 , 14 , 16 (FIG. 23A). [0146] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is formed in the device regions 36 , 14 , 16 (FIG. 23B). [0147] Then, a photoresist film 46 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography. [0148] Next, with the photoresist film 46 as a mask, fluorine ions are implanted in the silicon substrate 10 . The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 23C). [0149] Then, after the photoresist film 46 is removed, a photoresist film 44 exposing the device region 16 and covering the device regions 36 , 14 is formed by the usual photolithography. [0150] Next, with the photoresist film 44 as a mask, nitrogen ions are implanted in the silicon substrate 10 . The nitrogen ions (N + ) are implanted, e.g., at 5 keV acceleration energy and at a 4×10 14 cm −2 dose (FIG. 24A). [0151] Next, after the photoresist film 44 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. [0152] Then, the silicon substrate 10 is thermally oxidized by thermal oxidation combing the dry oxidation and the low pressure wet oxidation to form a gate insulation film 22 of the silicon oxide film in the device region 14 , a gate insulation film 24 of the silicon oxide film in the device region 16 and a gate insulation film 42 of the silicon oxide film in the device region 36 . At this time, fluorine ions are incorporated in the device region 36 , and nitrogen ions are incorporated in the device region 16 , whereby the enhanced oxidation takes place in the device region 36 , and the retarded oxidation takes place in the device region 16 . Accordingly, the gate insulation film 42 in the device region 36 is formed thick, the gate insulation film 24 in the device region 16 is formed thin, and the gate insulation film in the device region 14 is formed thinner than the gate insulation film 42 but thicker than the gate insulation film 22 (FIG. 24B). For example, when the dry oxidation for forming a 4 nm-thick silicon oxide film at 750° C. is followed by the low pressure wet oxidation at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine or nitrogen ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 6.8 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.0 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.5 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited. [0153] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 24C). [0154] As described above, according to the present embodiment, after fluorine ions and nitrogen ions are selectively implanted, the thermal oxidation combining the dry oxidation and the low pressure wet oxidation is performed as the thermal oxidation for forming the gate insulation film, whereby film thicknesses of the gate insulation films in the ion implanted regions can be selectively increased or decreased. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have higher reliability than those formed by the dry oxidation. [0155] In the present embodiment, an ion species for enhancing the enhanced oxidation is fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions or others, may be used. [0156] In the present embodiment, by the oxidation in which the dry oxidation is followed by the wet oxidation, the gate insulation films are formed, but the gate insulation films may be formed by the low pressure wet oxidation in a case that the retarded oxidation by nitrogen can be less. [0157] In the present embodiment, the gate insulation films of three different film thicknesses are formed, but gate insulation film of four or more different film thicknesses may be formed. [0158] A Fifth Embodiment [0159] The method for fabricating the semiconductor device according to a fifth embodiment of the present invention will be explained with reference to FIG. 25A- 25 D. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first to the fourth embodiments of the present invention shown in FIGS. 7A to 24 C are represented by the same reference numbers not to repeat or to simplify their explanation. [0160] FIGS. 25 A- 25 D are sectional views of the semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method. [0161] First, a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 14 , 16 (FIG. 25A). [0162] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is form by thermal oxidation in the device regions 14 , 16 defined by the device isolation film 12 (FIG. 25B) [0163] Next, a photoresist film 20 exposing the device region 14 and covering the device region 16 is formed by the usual photolithography. The photoresist film 20 is formed of a material which has etching resistance to a gas containing a halogen element. [0164] Next, the silicon substrate with the photoresist 20 formed on is exposed to fluorine plasma to incorporate fluorine selectively in the device region 14 of the silicon substrate 10 . [0165] For example, the silicon substrate 10 is introduced in to a vacuum system for magnetron plasma processing, and then a fluorine content gas, e.g., F 2 gas, is introduced into the vacuum system. Then, a substrate bias is applied to the back side of the silicon substrate 10 under a 0.01-10 Pa pressure to establish a negative voltage within 1 kV. Concurrently therewith, introducing electromagnetic waves of 200-2000 W of rf (e.g. 13.56 MHz) or microwaves are introduced into parallel plate electrodes to cause discharges, and the silicon substrate 10 is exposed to the plasma for about 10 seconds—about 3 minutes. Thus fluorine is incorporated in the silicon substrate 10 . [0166] Next, the photoresist film 20 is removed, and then the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. [0167] Next, the silicon substrate is thermally oxidized by the low pressure wet oxidation to form a gate insulation film 22 of the silicon oxide film in the device region 14 and a gate insulation film 24 of the silicon oxide film in the device region 16 . At this time, in the device region 14 , where fluorine ions are incorporated, the enhanced oxidation takes place. Thus, the gate insulation film 22 in the device region 14 is formed thick, and the gate insulation film in the device region 16 is formed thin (FIG. 25D). Thus, while the enhanced oxidation effect owing to the fluorine plasma processing is exhibited, wet oxidation film of good quality can be formed. [0168] Then, in the same way as in the method for fabricating the semiconductor device according to, e.g., the first embodiment shown in FIGS. 18A to 18 C, transistors including the gate insulation films 22 , 24 having different film thicknesses from each other are formed in the device regions 14 , 16 . [0169] As described above, according to the present embodiment, after the fluorine plasma processing is selectively performed, the thermal oxidation for forming the gate insulation films is performed, whereby a film thickness of the gate insulation film in the region subjected to the fluorine plasma processing can be selectively increased. The gate insulation films, which are formed by the wet oxidation, can have higher reliability than those formed by the dry oxidation. [0170] In the present embodiment, in place of applying rf or microwaves, electron beams may be applied to ionize fluorine to apply the fluorine ions to the silicon substrate 10 . [0171] In the present embodiment, as a fluorine content gas, F 2 gas is used, but, for example, ArF, KrF, XeF or other gases may be used. In place of fluorine, iodine or chlorine (Cl) or bromine (Br) may be incorporated, and, in this case, for example, a gas of Cl 2 , ArCl, KrCl, XeCl, Br 2 , ArBr, KrBr, XeBr, I 2 , ArI, KrI, XeI, or others can be used. [0172] In the same way as in the second to the fourth embodiments, gate insulation films of 3 or more different film thicknesses may be formed. [0173] Modifications [0174] The present invention is not limited to the above-described embodiments and can cover other various modifications. [0175] For example, in the above-described embodiments, the region for the thick gate insulation film to be formed in and the region for the thin gate insulation film to be formed in are the memory cell region and the peripheral circuit region, but are not essentially the memory cell region and the peripheral circuit region. For example, the memory cell region may be a region for the thin gate insulation film to be formed, and the peripheral circuit region is a region for the thick gate insulation film to be formed in. A region for high breakdown voltage input/output transistors to be formed in may have a thicker gate insulation film than other regions. It is preferable that regions for gate insulation films of different film thicknesses are selected suitably for device structures. [0176] In the above-described embodiments, the present invention are explained by means of fabricating n-type transistors, but the present invention may be applied to forming the gate insulation films of p-type transistors. It is possible that gate insulation films are different in film thickness between n-type transistors and p-type transistors. [0177] In the above-described embodiments, the present invention is applied to forming the gate insulation films but is applicable widely to forming insulation films of different film thicknesses by a single oxidation step. For example, for non-volatile memories, such as flash EEPROM, etc., it is necessary that a thin device isolation film is formed in the memory cell regions for the purpose of micronization, and a thick device isolation film is formed in the peripheral circuit region because peripheral circuits require high breakdown voltage units, such as charge pump circuits. Accordingly, the present invention is applied to a thermal oxidation step for forming the device isolation films, whereby the device isolation films of different film thicknesses can be simultaneously formed by a single thermal oxidation step. [0178] As described above, according to the present invention, after halogen ions are selectively implanted, the thermal oxidation for forming gate insulation films is performed, whereby the gate insulation film in a region with the halogen ions implanted can be selectively formed thick. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation. Especially by using fluorine as halogen ions, the silicon oxide film can have higher reliability than that formed without ion implantation. [0179] After xenon ions are selectively implanted, the thermal oxidation for forming gate insulation films is performed, whereby the gate insulation film in the ion-implanted region can be selectively formed thick. [0180] After nitrogen ions are selectively implanted, thermal oxidation combining the dry oxidation and low pressure wet oxidation is performed as the thermal oxidation for forming gate insulation films, whereby the gate insulation film in the ion implanted region can be selectively formed thin. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation.

A semiconductor device is fabricated by a method comprising the steps of: selectively introducing a halogen element or argon into a device region 14 of a silicon substrate 10; and wet oxidizing the silicon substrate 10 in an ambient atmosphere which an H 2 O partial pressure is less than 1 atm to thereby form a silicon oxide film 22 in the device region 14 of the silicon substrate 10, and a silicon oxide film 24 thinner than the silicon oxide film 22 in a device region 16 of the silicon substrate 10. Whereby the silicon oxide film in a device region 14 with the halogen element or argon introduced can be selectively formed thick. The silicon oxide films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation.

The U.S. Government has rights in this invention pursuant to Contract No. F08635-77-C-0173 awarded by the United States Air Force. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to mechanisms for locking and actuation of the firing pins of gun bolts in automatic guns, such as Gatling type guns, and, more particularly, to such mechanisms in gun bolts where the bolts are locked by cammed locking lugs. 2. Description of the Prior Art The use of cammed locking lugs to lock gun bolts to gun barrels is well known, and is shown, for example, in "The Machine Gun" by G. M. Chinn, Vol. IV, Parts X and XI, pp. 371, 384, 385, Dept. of the Navy, 1955. Therein are shown for example: "FIG. 6-76-Locking Rollers Are Cammed Free of Barrel Extension by Rails in Receiver." "FIG. 6-89 [and 6-90]-Recoiling Barrel Extension Cams Lugs Free of Bolt." In U.S. Pat. No. 3,608,427 issued Sept. 28, 1971 to R. H. Colby, there is shown a gun bolt which is locked by lugs which are nested in pockets in the recoiling gun barrel extension and which are swung out to lock the gun bolt by cam followers which ride in a stationary cam track. In U.S. Pat. No. 3,603,201, issued Sept. 7, 1971 to A. J. Aloi there is shown a firing pin in a drop lock type gun bolt in a Gatling type gun which is actuated by an aft annular cam. In U.S. Pat. No. 4,295,410, issued Oct. 20, 1981 to R. A. Patenaude et al there is shown a gun bolt in a Gatling type gun which is locked by locking lugs which are operated by a slide which is controlled by a supplemental annular cam. BRIEF DESCRIPTION OF THE INVENTION It is an object of this invention to provide a mechanism for precluding projection of the firing pin of a gun bolt forward of the face of the gun bolt when the gun bolt is not in its locked position. A feature of this invention is the provision of a gun bolt having a firing pin which is movable to and between an aft disposition whereat the forward end of said pin is aft of the face of the gun bolt and a forward disposition whereat said forward end is forward of said face, locking means movable to and between a locked disposition whereat said gun bolt is locked to fixedly close the chamber of the gun and an unlocked disposition, and intermediate means responsive to the disposition of said locking means for locking said pin in its aft disposition when said locking means is not in its locked disposition. BRIEF DESCRIPTION OF THE DRAWING These and other objects, features and advantages of the invention will be apparent from the following specification thereof taken in conjunction with the accompanying drawing in which: FIG. 1 is a perspective view of a portion of a gun bolt of the type shown in U.S. Pat. No. 4,294,158, issued Oct. 13, 1981 to R. A. Patenaude et al, which is improved by the incorporation of an embodiment of this invention; FIG. 2 is a top view of the gun bolt of FIG. 1 showing the gun bolt unlocked; FIG. 3 is similar to FIG. 2 but showing the gun bolt partially locked; FIG. 4 is similar to FIG. 3 but showing the gun bolt fully locked; FIG. 5 is a partial detail view in transverse cross-section showing the locking slide captured to the body of the gun bolt; FIG. 6 is partial detail view in longitudinal cross-section showing the wing lock in elevation as nested in the pocket in the rotor; FIG. 7 is a partial detail view in transverse cross-section showing the gun bolt journaled in the rotor; FIG. 8 is a partial detail view in longitudinal cross-section showing the cam follower and detent mechanism of the locking slide; FIG. 9 is a top view in partial cross-section of the gun bolt of FIG. 1 showing a portion of the firing pin mechanism and the gun bolt unlocked; FIG. 10 is similar to FIG. 9 but showing the gun bolt partially locked; FIG. 11 is similar to FIG. 10 but showing the gun bolt fully locked; FIG. 12 is a detail view in side longitudinal cross-section of the gun bolt showing a portion of the firing pin mechanism; FIG. 13 is a detail view in front cross-section of the gun bolt showing a portion of the firing pin mechanism; and FIG. 14 is a detail side view of the gun bolt with locking lug removed. DESCRIPTION OF THE INVENTION This invention is incorporated in a gun bolt of the type shown in U.S. Pat. No. 4,294,158, issued Oct. 13, 1981 to R. A. Patnaude et al, which in turn is incorporated in a gun of the type having a small diameter rotor shown in U.S. Pat. No. 3,834,272 issued Sept. 10, 1974 to R. A. Patenaude et al and U.S. Pat. No. 4,114,511 issued Sept. 19, 1978 to R. A. Patenaude. Of course, the invention has utility in other gun bolts in other guns. The gun bolt embodying this invention as shown in FIG. 1 includes a bolt body 10 and a slide 12. As shown in FIG. 5, the body has, in part, a T-shaped cross-section wherein the ends of the "T" provide rails 14 and the slide has a pair of depending and inward-going sides 16 encircling the rails to capture the slide to the body while permitting longitudinal relative motion. There are a plurality of gun bolts, e.g., three, one for each gun barrel 17. The gun barrels are fixed to the rotor 18 which is journaled for rotation in a housing 19, and each gun bolt is journaled for longitudinal reciprocation in a respective channel 20 in the rotor, as shown in FIG. 7. As is well known, the rotor in a Gatling type gun serves as a receiver. Each of a symmetric pair of locking lugs 22 is nested in a respective recess 24 in the rotor 18 adjacent the channel 20. A pin 26, which passes through a bore 28 in the lug 22 into a blind bore 30 in the rotor, pivotally captures the lug in the rotor. Each gun bolt body 10 has a stud 32 fixed thereto on which is journaled a cam follower roller 34 which rides in a cam track 36 formed in the interior wall of the housing 19, and which cam track serves to reciprocate the bolt fore and aft as the rotor revolves about its longitudinal axis. The rotor may be driven by appropriate means, such as an external drive, as shown in U.S. Pat. No. 3,834,272, supra. Each slide 12 has a stud 38 fixed thereto on which is journaled a cam follower roller 40 which rides in a cam track 42 formed in the interior wall of the housing, and which cam track serves to reciprocate the slide relative to its respective gun bolt, as the assembly of the gun bolt and the slide reciprocates relative to the rotor. The cam track 42 is not continuous, but rather is provided only where necessary to provide relative movement between the slide and the bolt body. A detent mechanism is provided to hold the slide and the bolt body against relative movement. A plunger 43 is disposed in a blind bore 43a and is biased outwardly by a helical compression spring 43b. The plunger has a main body portion 43c of relatively large diameter and a cam follower portion 43d of relative smaller diameter. The follower portion clears and passes through a slot 43e in the slide. The body portion 43c will seat in either of two cups 43f or 43g in the slot, and when so seated, locks the slide of the bolt body. The plunger is withdrawn from either cup by means of a cam surface 43h depressing the follower against the bias of the spring. Each of a symmetric pair of actuator lugs 44 is pivotally captured to the slide 12 by a respective pin 46 and nested within a respective recess 48 into the side of the gun bolt body 10. Each recess 48 has a respective ramp surface 50, which serves to cam the distal end of the lug 44 outwardly when the slide 12 is moved aft relative to the gun bolt body 10. As the distal end of the lug 44 moves outwardly it abuts a cam following surface 51 of the aft end 52 of the adjacent locking lugs 22 which is journaled on pivot 26 in the rotor and swings said aft end 52 outwardly and, thereby, the forward end 54 of the locking lug inwardly. As the forward end 54 swings inwardly, it enters a recess 55 in the bolt body aft of the head 56 of the bolt. This recess has an aft facing surface 58 which receives the forward facing and end surface 60 of the locking lug. Thus pressure against the face of the head 56 of the bolt body 10 is transmitted across the surfaces 58 and 60, through the locking lugs 22, to an arcuate surface 61 of the rotor 18. Each of the pair of locking lugs 22 also has a respective stud 62 fixed to the forward end. The forward end of the slide 12 has a pair of somewhat arcuate slots 64 cut into its underface. As the slide 12 progressively moves aft, the lugs 44 progressively swing out, the lug aft ends 52 progressively move out, and the lug forward ends 54 progressively move in and the lugs 62 progressively enter into the respective arcuate slots 64. When the slide 12 is fully aft, the lugs 62 are fully into the blind forward ends of the slots, so that the slide precludes any pivotal movement of the locking lug. Thus the slide 12 which is controlled by its cam follower 40 in the cam track 42, not only drives the locking lugs into their bolt locking configuration by means of the ramp surfaces 50 and the actuator lugs 44, but also captures the locking lugs in their bolt locking configuration by means of the arcuate slots 64, so that any possibility of unlocking movement of the locking lugs at the time of firing is precluded. The slide also has a symmetric pair of shoulders with respective ramp surfaces 66, which project into respective recesses 67 in each locking lug 22. Each recess has a cam following surface 68, and as the slide moves forwardly on the bolt body, the ramp surface 66 engages the surface 68 to cam the locking lugs outwardly, while concurrently the cut out 64 clears the stud 62. A stud 70 is integral with the body of the gun bolt and has a cross bar having two ends 72 which overlie an upwardly facing surface 74 of the slide. These overlying ends preclude any possible upward movement of the slide which might otherwise tend to permit disengagement of the studs 62 from the arcuate slots 64. A firing pin 100 is disposed in a longitudinal bore 102 in the gun bolt body 10. A cocking lever 104 passes through a radially extending slot 106 in the aft end of the body 10 and is fixed to the aft end of the firing pin. The cocking lever rides on the cam surface 108 of an annular firing cam 110 which has a low or forward uncocked level 112, a ramp or cocking level 114, an up or aft cocked level 116, and a firing drop off 118. A helical firing spring 120 is disposed on the firing pin and is compressed and released by the operation of the cocking lever. The firing pin has a substantially conical head 122 which is adapted to pass through a reduced opening 124 into the face 126 of the head 56 of the gun bolt. The pin has a portion 126a of reduced diameter which provides a forward facing annular shoulder 128. A pair of retainer lugs 130 are disposed in a cross-slot 132 formed in the bolt body and extending between the recesses 55. Each lug 130 is pivotally mounted to the body by a pin 134 passing through respective bores in the bolt body. Each lug 130 also has a cam follower pin 136 projecting therefrom. The forward underside portion of the slide 12 has a part of stepped cam surfaces 140, 142, 144, for driving the respective pins 136. The forward ends of the retainer lugs 130 are normally biased apart by a helical compression spring 146 whose ends project into blind bores 148 in the lugs 130. The aft ends of the lugs, which have respective curved surfaces to straddle the reduced portion 126a of the firing pin, are thus normally biased together and abut the forward facing shoulder 128 of the firing pin, thereby precluding forward movement of the firing pin. When the slide 12 is forward relative to the bolt body, in the bolt unlocked disposition shown in FIG. 9, the part of inner cam surfaces 144 respectively abut the pair of cam follower pins 136, and holds the part of retainer lugs 130 in their firing pin blocking disposition. When the slide 12 is aft relative to the bolt body, in the bolt locked disposition shown in FIG. 11, the cam surfaces 144 are clear of the pair of cam follower pins 136, but the spring 146 would continue to bias the aft ends of the retainer lugs together. However, when the forward ends 54 of the bolt locking lugs 22 are each present and are swung inwardly into their bolt locking disposition, they respectively abut the forward ends of the retainer lugs 130 and cam them together against the bias of the spring 146, so that the aft ends of the retainer lugs 130 clear the annular shoulder 128 and the firing pin is free to move forward under the control of the cocking lever 104 and the spring 120. If both locking lugs 22 are not present and swung into their bolt locking dispositions, the retaining lugs will not both be released from the annular shoulder 128, and the firing pin will be blocked from camming forward and projecting forward of the face of the gun bolt, irrespective of the action of the cocking lever and the main spring. While the invention has been shown embodied in a Gatling type gun, it will be obvious that it has application to single barrel guns wherein the gun bolt is driven by rotating drum cam, such as is shown in U.S. Pat. No. 1,786,207 issued to R. F. Hudson on Dec. 23, 1930. In such case the two cam tracks 36 and 42 will be formed on the drum cam, rather than on the housing, and the gun bolt assembly will reciprocate in the receiver. In either case relative motion is provided between the cam tracks and the gun bolt assembly.

A feature of this invention is the provision of a gun bolt having a firing pin which is movable to and between an aft disposition whereat the forward end of said pin is aft of the face of the gun bolt and a forward disposition whereat said forward end is forward of said face, locking means movable to and between a locked disposition whereat said gun bolt is locked to fixedly close the chamber of the gun and an unlocked disposition, and intermediate means responsive to the disposition of said locking means for locking said pin in its aft disposition when said locking means is not in its locked disposition.

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10/821,633 (Attorney Docket No. 28863-713.201), filed Apr. 9, 2004, now U.S. Pat. No. ______, the entire content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to devices, systems, and methods for percutaneous sealing of a puncture site in tissue tracts. More specifically, the present invention relates to devices, systems, and methods for hemostasis of vascular puncture sites in human bodies. [0004] Percutaneous access of blood vessels in the human body is routinely performed for diagnostics or interventional procedures such as coronary and peripheral angiography, angioplasty, atherectomies, placement of vascular stents, coronary retroperfusion and retroinfusion, cerebral angiograms, treatment of strokes, cerebral aneurysms, and the like. Patients undergoing these procedures are often treated with anti-coagulants such as heparin, thrombolytics, and the like, which make the closure and hemostasis process of the puncture site in the vessel wall at the completion of such interventional procedures more difficult to achieve. [0005] Various devices have been introduced to provide hemostasis, however none have been entirely successful. Some devices utilize collagen or other biological plugs to seal the puncture site. Alternatively, sutures and/or staples have also been applied to close the puncture site. External foreign objects such as plugs, sutures, or staples however may cause tissue reaction, inflammation, and/or infection as they all “leave something behind” to achieve hemostasis. [0006] There is also another class of devices that use the body's own natural mechanism to achieve hemostasis wherein no foreign objects are left behind. Such devices typically provide hemostasis by sealing the puncture site from the inside of the vessel wall wherein the device is left in place in the vessel lumen until hemostasis is reached and thereafter removed. Although such devices have achieved relative levels of success, removal of the device at times may disrupt the coagulant that is formed at the puncture site. This in turn may cause residual bleeding which requires the device user to apply a few minutes of external manual pressure at the puncture site after the removal of the device to achieve complete hemostasis. [0007] Still further devices that also uses body's natural mechanism to achieve hemostasis comprise a locator on the inside of the vessel wall and a balloon to directly contact and seal the puncture site from the outside surface of the vessel wall. This balloon is directly against and in contact with the outside surface of the vessel wall for sealing the hole and achieving hemostasis. There are several drawbacks associated with direct contact and compression of the outside surface of the vessel wall. For example, excessive compression may cause herniation of the balloon through the puncture site into the vessel, which in turn may cause resumption of bleeding. Further, such devices may not be easily applied to severely tortuous vessels where direct access and contact with the vessel surface to seal the puncture may be difficult to achieve. Moreover, such devices may substantially disrupt the flow of blood in the vessel during its application. Further, intimate device contact with the puncture site of the vessel wall may not provide sufficient coagulant. Still further, removal of the device may cause disruption of the coagulant at the puncture site thereby increasing the chances for resumption of bleeding and hematoma formation (i.e., leaking of blood into interstitial space). [0008] In light of the above, it would be desirable to provide improved devices, systems, and methods for complete hemostasis of a puncture site in a body lumen, particularly blood vessels of the human body. It would be particularly desirable if such devices, systems, and methods utilized the body's own natural healing mechanism to achieve hemostasis without disrupting coagulation formation at the puncture site. It would be further desirable if such devices, systems, and methods prevented any vessel herniation or vessel flow disruption. [0009] Further, such devices, systems, and methods should be easy to implement on a variety of vessel anatomies. At least some of these objectives will be met by the devices, systems, and methods of the present invention described hereinafter. [0010] 2. Background of the Invention [0011] Expansible devices for use in blood vessels and tracts in the body are described in co-pending U.S. patent application Ser. No. 10/718,504, assigned to the assignee of the present application. The following U.S. patents and publications may be relevant to the present invention: U.S. Pat. Nos. 4,744,364; 4,852,568; 4,890,612; 5,108,421; 5,171,259; 5,258,000; 5,383,896; 5,419,765; 5,454,833; 5,626,601; 5,630,833; 5,634,936; 5,728,134; 5,861,003; 5,868,778; 5,951,583; 5,957,952; 6,017,359; 6,048,358; 6,296,657; U.S. Publication Nos. 2002/0133123 and 2003/0055454. [0012] The full disclosures of each of the above mentioned references are incorporated herein by reference. BRIEF SUMMARY OF THE INVENTION [0013] The present invention provides improved devices, systems, and methods for complete hemostasis of a puncture site in a body lumen, particularly blood vessels of the human body. Such closure devices, systems, and methods utilize the body's own natural healing mechanism to achieve hemostasis without leaving any foreign objects behind. The devices of the present invention allow for enhanced coagulant formation at the puncture site, increasing the integrity of hemostasis. Further, removal of such sealing devices and systems after hemostasis is achieved does not incite disruption of the coagulation formation at the puncture site. This in turn reduces the risk of bleeding and hematoma formation, thrombosis, embolization, and infection. The devices, systems, and methods of the present invention substantially avoid dangers of vessel herniation or vessel flow disruption, particularly in lower extremities. Further, such devices, systems, and methods are easy to implement without numerous intermediary steps on a variety of vessel anatomies, such as severely tortuous vessels. [0014] In a first aspect of the present invention, a system for hemostasis of a puncture site in a body lumen is provided. One system comprises a locating assembly and a compression assembly. The locating assembly generally comprises a first tubular member having a proximal end and a distal end and an expansible member disposed on the distal end of the first tubular member. The compression assembly is at least partially coaxial with the locating assembly. The compression assembly comprises a second tubular member having a proximal end and a distal end and a balloon disposed at the distal end of the second tubular member. In particular, a distal end of the balloon is positionable at a predetermined distance away from a wall of the body lumen. An inflation assembly is also provided. It is coupleable to a proximal end of the compression assembly and in communication with the balloon. [0015] Hence, the present invention is designed such that the compression balloon is deployed outside the vessel wall at a predetermined distance from the outside surface of the vessel wall. The balloon, during inflation, compresses the subcutaneous tissue between the vessel wall and the distal surface of the balloon. The compressed tissue can then overcome the blood pressure and hence stop blood from flowing out to achieve hemostasis. It will be appreciated that the balloon is not used as means to directly contact and seal the hole in the vessel wall. Rather, the present invention uses the tissue as the compression medium against the puncture site to achieve hemostasis. The tissue left between the balloon and the vessel wall allows for enhanced coagulation in the vicinity of the puncture site. This allows for more secure hemostasis with reduced chances of delayed bleeding. [0016] The locating assembly further comprises deployment means coupleable to the proximal end of the first tubular member so as to move the expansible member between a contracted configuration and an expanded configuration. The expansible member in the expanded configuration typically has a diameter in a range from about 0.05 inch to about 0.5 inch, preferably in a range from about 0.15 inch to about 0.30 inch. The expansible member generally comprises stainless steel, shape memory material, superelastic material or like medical grade material. The locating assembly may further comprise a temporary hemostasis member, such as a plug, coupleable to the distal end of the first tubular member. In some embodiments, the compression balloon may be disposed between the distal end of the second tubular member and a proximal end of the temporary hemostasis member so as to form an integrated, unitary assembly. In other embodiments, it is preferable that the balloon is disposed solely on the distal end of the compression assembly, as described in more detail below. In still other embodiments, the locating assembly may further comprise a deformable membrane at least partially disposed over the expansible member in lieu or in addition to the temporary hemostasis plug. [0017] Generally, the compression balloon remains proximal a distal end of the expansible member. This predetermined positioning may be implemented in any number of ways. For example, mechanical or visual means on the locating or compression assembly like detents, latches, flanges, other mechanical interference, visual markings, and like mechanisms, may provide positioning of the compression balloon at a fixed distance from the expansible member which locates the balloon outside the vessel wall at the predetermined distance. The predetermined distance of the distal end of the compression balloon from the vessel wall is in a range from about 0.05 inch to about 0.5 inch, preferably in a range from about 0.2 inch to about 0.3 inch. The compression assembly may be fixed relative to the locating assembly. Alternatively, the compression assembly may be moveable relative to the locating assembly. [0018] In some instances, the locating assembly may be laterally offset from an axis of the compression assembly. As discussed above, the locating assembly and compression assembly may also form an integrated catheter assembly structure for ease of operation. [0019] The compression balloon may comprise one or more materials selected from the group consisting of polyethylene, polyethylene terephthalate, polytetrafluroethylene, nylon, polyurethane, silicone, latex, polyvinyl chloride, and thermoplastic elastomer. The compression balloon may be pre-formed or pre-molded symmetrically or asymmetrically. In some embodiments, the balloon has an expanded configuration comprising a conical shape. In other embodiments, the balloon comprises a plurality of concentric folds that are unfolded in an expanded configuration. In further embodiments, the balloon has an expanded configuration comprising a concave distal end. This last design allows for formation of a concave surface relative to the vessel wall when the balloon is inflated, allowing for more coagulant to form at the puncture site which would likely provide for enhanced hemostasis. [0020] The compression assembly may further comprise a radio-opaque material so that the compression balloon placement may be imaged and viewed via fluoroscopy. In some embodiments, a coating on an outer surface of the balloon may be applied. The coating may comprise electrically conductive material for the delivery of energy, such as radio frequency energy or microwave energy to further promote and accelerate complete hemostasis. The coating may further be designed to deliver ultrasound energy. Alternatively, the coating may comprise clot promoting agents, such as thrombin, or anti-infection agents. In the case of agent release, the balloon may alternatively comprise a semi-permeable membrane, allowing the inflation medium, which may be chosen from clot promoting solutions, to diffuse into the surrounding tissue. The inflation assembly generally comprises a source of at least air, fluid, clot promoting agent, anti-infection agent, radio-opaque medium, or a combination thereof. [0021] In another aspect of the present invention, devices for hemostasis of a puncture site in a body lumen are also provided. One device comprises a first tubular member having a proximal end and a distal end and a second tubular member having a proximal end and a distal end. The second tubular member is at least partially coaxial with the first tubular member so as to define an inflation lumen therebetween. A balloon is disposed at the distal ends of the first and second tubular members and in communication with the inflation lumen. A distal end of the balloon is postionable at a predetermined distance away from a wall of the body lumen. The characteristics of the compression balloon are generally as described above. In an additional embodiment, the balloon may comprise an expansible member and a deformable membrane at least partially disposed over the expansible member as described in greater detail in co-pending U.S. patent application Ser. No. 10/718,504, assigned to the assignee of the present application and incorporated herein by reference. [0022] In yet another aspect of the present invention, methods for hemostasis of a puncture site in a body lumen are also provided. One method comprises providing a compression assembly comprising a tubular member having a proximal end and a distal end and a balloon disposed at the distal end of the tubular member. The compression assembly is inserted through an opening in a skin surface. A distal end of the balloon is positioned at a predetermined distance away from a wall of the body lumen and against subcutaneous tissue. The balloon is inflated to an expanded configuration. This causes forward elongation of the balloon which compresses subcutaneous tissue between the distal tip of the balloon and the vessel wall. This tissue compression against the puncture site is the mechanism that provides hemostasis. As described above, the balloon is only engageable against subcutaneous tissue surrounding the body lumen wall, wherein the body lumen comprises a blood vessel. The predetermined distance may be in a range from about 0.05 inch to about 0.5 inch, preferably in a range from about 0.2 inch to about 0.3 inch. The balloon may be imaged during positioning. Further, radio frequency energy, ultrasound energy, microwave energy, clot promoting agents or anti-infection agents may be delivered to the puncture site. [0023] Since the compression assembly of the present invention is seated against the subcutaneous tissue, and is not in contact with the vessel wall, there is further coagulant formation and less chances of disruption of the coagulant at the puncture site (e.g., arteriotomy site) when the device is removed. It is thus expected that the chances of resumption of bleeding or complications such as formation of hematoma are greatly reduced. Further, since the compression balloon is at a predetermined distance away from the vessel wall and against subcutaneous tissue, the risks of the balloon herniating into the puncture site and into the vessel are greatly reduced. Moreover, as the compression assembly relies on tissue compression and not intimate and complete seating of the balloon around the periphery of the puncture site to achieve sealing of the hole, it can therefore be applied with less precision and is less dependant on the anatomy of the site. In other words, the compression assembly is more forgiving in its application since it is less reliant on positioning and as such may be even applied to seal severely tortuous vessels. The compression assembly can also be used more reliably and therefore has a greater chance of success. [0024] The proposed design of the balloon and the attachment technique provide for forward movement of the distal end of the balloon towards the vessel wall, causing tissue compression, when inflated. For example, inflating may comprise at least one of axial or radial dilation of the balloon so as to cause targeted micro compression of the subcutaneous tissue surrounding the body lumen wall. Alternatively, inflating may comprise expanding a superior aspect of the balloon greater than an inferior aspect of the balloon. Since the tubular member is often not positioned perpendicularly to the vessel, this embodiment compensates for the difference in the distance between the top distal tip of the balloon to the vessel wall and the bottom distal tip of the balloon to the vessel wall so as to provide for more even compression over the puncture site. Optionally, inflating may comprise expanding a distal face of the balloon at an angle to the tubular member similar to an angle formed between the tubular member and the body lumen. Inflating may also comprise simply deploying the balloon to an expanded configuration comprising a conical shape. Still further, inflating may comprise unfolding concentric folds of the balloon to an expanded configuration or deploying the balloon to an expanded configuration having a concave distal end. [0025] A locating assembly comprising a second tubular member having a proximal end and a distal end and an expansible member disposed on the distal end of the second tubular member is also preferably provided. The locating assembly may be inserted through the opening in the skin and in the puncture site prior to or simultaneously with compression assembly insertion. The expansible member is deployed to an expanded configuration within the body lumen having a diameter in a range from about 0.05 inch to about 0.5 inch. The puncture site in the body lumen wall is then located and temporary hemostasis of the puncture site with a plug coupleable to the distal end of the second tubular member may also be provided. After balloon inflation and initial compression, the locating assembly is contracted and withdrawn from the skin. [0026] A further understanding of the nature and advantages of the present invention will become apparent by reference to the remaining portions of the specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0027] The following drawings should be read with reference to the detailed description. Like numbers in different drawings refer to like elements. The drawings, which are not necessarily to scale, illustratively depict embodiments of the present invention and are not intended to limit the scope of the invention. [0028] FIGS. 1A and 1B illustrate a locating assembly in an expanded configuration and retracted configuration respectively. [0029] FIG. 1C illustrates a balloon compression assembly in a collapsed configuration. [0030] FIG. 1D illustrates a system for hemostasis of a puncture site in a body lumen employing the assemblies of FIGS. 1A-1C constructed in accordance with the principles of the present invention. [0031] FIGS. 2A and 2B illustrate another embodiment of the locating assembly in a retracted configuration and an expanded configuration respectively that may be employed in any of the systems disclosed herein. [0032] FIGS. 3A and 3B illustrate yet another embodiment of the locating assembly in a retracted configuration and an expanded configuration respectively that may be employed in any of the systems disclosed herein. [0033] FIGS. 4A and 4B illustrate another embodiment of the balloon that may be employed in any of the compression assemblies disclosed herein. [0034] FIGS. 5A through 5C illustrate yet another embodiment of the balloon that may be employed in any of the compression assemblies disclosed herein. [0035] FIGS. 6A and 6B illustrate a further embodiment of the balloon that may be employed in any of the compression assemblies disclosed herein. [0036] FIGS. 7A through 7C illustrate a still further embodiment of the balloon that may be employed in any of the compression assemblies disclosed herein. [0037] FIGS. 8A through 8G illustrate a method for hemostasis of a puncture site in a body lumen employing the system of FIG. 1D . [0038] FIGS. 9A through 9C illustrate another system embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. [0039] FIG. 10 illustrates yet another system embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. [0040] FIGS. 11A through 11C illustrate a further system embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0041] Referring to FIGS. 1A through 1D , an exemplary embodiment of a system 10 for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention is illustrated. The system generally comprises a locating/temporary hemostasis assembly 11 as illustrated in FIG. 1 A and a compression assembly 50 as illustrated in FIG. 1C . The locating/temporary hemostasis assembly 11 comprises a flexible elongated tubular member 12 and a locating feature 13 . The locating feature 13 comprises an expansible member which can move between an expanded state, as shown in FIG. 1A , and a contracted state, as shown in FIG. 1B . A membrane may be present that fully or partially covers this expansible member 13 . Deployment means of the expansible member 13 located at a proximal end of the tubular member 12 may comprise a handle 14 and push/pull member 15 combination. The handle assembly 14 at the proximal end can facilitate the movement of the expansible member 13 via the push/pull member 15 which connects the handle assembly 14 to the expansible member 13 . This member 15 may be in the form of a wire of sufficient column strength to deploy and retract the expansible member 13 . It will be appreciated that the above depictions are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the system 10 . This applies to all depictions hereinafter. [0042] A distal end of tubular member 12 , just proximal to the expansible member 13 , is of sufficient diameter to temporarily seal the puncture in the vessel wall. Hemostasis plug 16 temporarily stops bleeding while the compression balloon is being deployed. The temporary hemostasis plug 16 is tapered at a proximal end 17 to facilitate its use and avoid any potential binding. Plug 16 may have a minimum length of 0.05 inch or it may extend the entire length of the tubular member 12 . Plug 16 may have a diameter in range from about 0.04 inch to about 0.2 inch. The effectiveness of the plug 16 to achieve temporary hemostasis may depend on a sheath size and the extent of the dilation of the puncture site. In such cases, the assembly 11 may be designed and manufactured to be used in conjunction with a specific size or a range of sheath sizes. Temporary hemostasis plug 16 may then be tailored accordingly. For example, procedures using a 5 to 6 Fr sheaths may have a temporary hemostasis plug that is approximately 0.070 inch in diameter. This diameter is large enough to produce temporary hemostasis yet small enough to go through a 5 Fr sheath. Plug 16 may also fully or partially house the contracted expansible member 13 . It is generally desirable to remove the sheath once the closure assembly 11 is applied. Therefore, locating/temporary hemostasis assembly 11 may have a smaller cross-sectional profile than an inside diameter of the sheath used. [0043] Referring now to FIG. 1C , the compression assembly 50 of the hemostasis system 10 includes elongated tubular membel l s 51 and 53 and compression balloon 55 . An inner diameter of first tubular member 51 is large enough so that it can preferably accept all, or at least a portion of the locating/temporary hemostasis assembly 11 . As shown, a proximal end of compression tubular member 51 is equipped with a sealing mechanism 52 such as a silicone seal. Since compression tubular member 51 may be in fluid communication with blood, seal 52 prevents blood from flowing out of the system 10 . Seal 52 may be disposed anywhere along a length of the compression tubular member 51 . The length of compression member 51 from the seal 52 to a distal tip thereof is substantially shorter than a length of the locating/temporary hemostasis assembly 11 , approximately half the length. Locating assembly 11 may have a length in a range from about 4 inches to about 18 inches, preferably from about 8 inches to about 12 inches. This ensures that the handle assembly 14 of assembly 11 can be pushed through seal 52 when member 11 is positioned in the vessel. [0044] The second flexible tubular member 53 may be concentric with and contain the first tubular member 51 . This second tubular member 53 may expand distally the full length of the first tubular member 51 . The two tubular members 51 and 53 may bifurcate proximally as depicted by arrow 54 . It will be appreciated that these two tubular members 51 and 53 may be fabricated from a multi-lumen tubing using common extrusion processes. In general, all tubular members 12 , 51 , and 53 may be formed from polyester (e.g., polyethylene terephthalate), PEBAX™, PEEK™, nylon, polyvinyl chloride, and like medical grade materials. A distal end of the compression assembly 50 is equipped with a compression balloon 55 which is attached at a distal end 56 and a proximal end 57 thereof. The balloon 55 is in communication with an inflation lumen 58 that is formed between the two tubular members 51 and 53 of the compression assembly 50 . A proximal end of the second tubular member 53 is equipped with a luer lock 59 for attaching a syringe 60 or the like to pump air or fluids, such as saline solution, into compression balloon 55 for the purpose of inflating the balloon. The inflation assembly may also be equipped with a stopcock 61 , distal to luer lock 59 , that maintains the pressure once the balloon is inflated to its desired pressure. The device may also include a pressure relief valve 62 that automates and visually verifies when the desired pressure of the compression balloon 55 is reached. The pressure relief valve 62 would take the guess work out of the required amount of pressure to be applied to the compression balloon 55 . [0045] Referring now to FIG. 1D , the interaction of assemblies 11 and 50 of the closure system 10 is shown. Locating/temporary hemostasis assembly 11 slides inside compression assembly 50 such that the distal tip 56 of compression balloon 55 gets located at a fixed distance proximal to locating expansible member 13 of assembly 11 . The locating process may be achieved by aligning visual marks on the two assemblies, such as aligning mark 18 of locating assembly 11 to be just outside seal 52 of compression assembly 50 . Alternatively, the locating process may be achieved as a result of a mechanical interference or a latching mechanism. The latching mechanism may be designed to provide an audio or a tactile feedback when the two tubular assemblies 11 and 50 latch. Once the two assemblies are latched, the latching mechanism can allow assembly 11 to move distally with minimal force. This detent, however, resists further forward movement of compression assembly 50 relative to assembly 11 . The distal movement of assembly 11 relative to compression member 50 may be desirable when the compression balloon 55 is inflated. The inflation of the compression balloon 55 may push the vessel wall distally. Having assembly 11 move with minimal force, such as 1 to 20 ounces, preferably 5 to 10 ounces, in the same direction would eliminate exerting stress on the vessel wall. [0046] The expansible member 13 of the locating assembly 11 may assume a variety of forms. Some are deployed by pushing the deployment means 15 forwardly. FIGS. 2A and 2B show an example of such a push type expansible member 13 ′ in contracted and deployed states, respectively. In particular, push/pull member 15 is pushed distally as depicted by arrow 9 to deploy fan-like expansible member 13 ′. Others may have the deployment means 15 connected to a distal end of the expansible member 13 ″ and to deploy the expansible member 13 ″ the deployment means is pulled back. FIGS. 3A and 3 B illustrate an example of a pull type expansible member 13 ″ in contracted and deployed states, respectively. In particular, push/pull member 15 is pulled proximally as depicted by arrow 8 to deploy hooks or prongs 13 ″. [0047] The deployed expansible member 13 produces a cross-sectional diameter that is substantially large so that when the assembly 11 is pulled back in the vessel and the expansible member is seated against the vessel wall, it can produce substantial resistance to the movement of the expansible member and therefore locate the assembly 11 against the puncture site inside the vessel lumen. The expansible member 13 , in deployed state, may produce a feature that is in a range from about 0.05 inch to about 0.5 inch in diameter, preferably from about 0.15 inch to about 030 inch. The expansible member 13 may be made from suitable metals such as stainless steel, shape memory material, superelastic material (e.g., NITINOL™ wire), etc. which can be elongated, contracted, or constrained without permanent deformation, but at body temperature, when freed or unconstrained returns to the expanded configuration. [0048] Compression balloon 55 is designed to perform various functions and exhibit particular behavior, specifically in the case of pre-formed or pre-molded balloons. For example, the proximal end 57 of the balloon 55 may be made in a conical form. FIG. 4A illustrates an example of a simple conical shaped compression balloon 70 . During inflation of the balloon 70 the portion closer to the apex 71 inflates to its maximum diameter first, and then inflation is propagated distally. This inflation process may aid in stabilizing the balloon 70 in the tissue and prevents lateral displacement of the compression assembly 50 . [0049] Referring now to FIG. 5A , the balloon may alternatively comprise a plurality of concentric folds that would be unfolded when pressurized. FIG. 5A illustrates a compression balloon 80 prior to assembly attachment. Balloon 80 incorporates a plurality of folds 81 . The process of unfolding causes the distal end 82 of the balloon to move forward, compressing the tissue in front of the balloon against the puncture site. Feature 83 , just proximal to the balloon attachment area 84 , folds over the attachment point as the balloon unfolds forwardly to allow for balloon elongation. FIGS. 5B and 5C illustrate the attached balloon 80 prior to inflation and after inflation, respectively. [0050] Referring now to FIG. 6A , yet another design of the compression balloon prior to attachment to the assembly is shown. Balloon 85 is folded and stacked between two attachment points 86 and 87 . FIG. 6B illustrates this balloon 85 at inflation. The design and attachment of the balloon 85 may allow for the forward tissue compression. It also can form a concave distal end 88 at full inflation. The concave feature 88 of the balloon 85 may allow for more coagulant to form at the puncture site. [0051] Referring now to FIG. 7A , another example of a balloon prior to attachment to the assembly is shown. Since the entry of the sheath to the vessel wall may not be perpendicular, the balloon may be molded asymmetrically. With balloon 90 at full inflation, more elongation is obtained on the top superior side relative to the bottom inferior side. This may be achieved by incorporating deeper folds 91 in the balloon material on the side with greater elongation requirements and shallower folds 92 on the opposite side. Feature 93 just proximal to the attachment point 94 may allow for the balloon elongation by folding over the attachment point 94 when the balloon is pressurized. In such a design, locating/temporary hemostasis assembly 11 may not be concentric to the compression assembly, but rather offset from the compression assembly. For example, assembly 11 may be placed closer to the inferior wall 92 of the compression balloon 90 . This offset compensates for turn 95 generated during balloon 90 inflation as the result of its asymmetrical nature, and consequently centers the distal end 96 of the balloon over the puncture site at full inflation, as shown in FIG. 7C . FIG. 7B depicts this balloon design prior to inflation. It should be clear that if the molding process allows, the balloon may be designed with a distal face at an angle to the assembly shaft similar to the angle that the sheath makes with the vessel wall, to compensate for such an effect. [0052] Referring back to FIG. 4B , the balloon may be designed or attached such that at full inflation, the distal face of the balloon forms a concave surface with respect to the vessel wall. In a simple conical balloon 70 , this may be accomplished by attaching balloon 70 on the assembly shaft at location 72 which is proximal to point 73 where a fully inflated, unconstrained balloon may extend to. In the case of balloon with folds, such as balloons 80 and 90 , this may be accomplished by making features 83 and 93 shorter than the increase in the length of the balloon as a result of inflation. [0053] The compression balloon 55 , 70 , 80 , 85 , or 90 is generally formed of materials that can withstand elevated pressures. The balloon should be designed to withstand pressures high enough to dilate the subcutaneous tissue around the tissue track and to be able to compress the tissue against the puncture site. Polyethylene, polyethylene terephthalate, polytetrafluroethylene, nylon, polyurethane, silicone, latex, polyvinyl chloride, and thermoplastic elastomer with different durometers, are examples of such materials. These materials offer different characteristics. Some can be molded to exhibit a specific shape when inflated, and some are elastomeric. The advantage of elastomeric materials over other high pressure materials is their elongation characteristics. Therefore, elastomeric materials may have a smaller profile prior to inflation. However, they may not be pressurized as high. The compression balloon may also incorporate radio-opaque materials, so that balloon placement may be imaged and verified. It may also be desirable to deliver electrical energy, such as radio frequency energy and the like, to the puncture site to accelerate the hemostasis process. In such a case the compression balloon may be coated with electrically conductive material to provide means of delivering such energy. [0054] It should also be noted that the compression member, thus far referred to as compression balloon, may be composed of an expansible member that is fully or partially covered by a membrane. This compression assembly when deployed can provide for the radial dilation of the surrounding tissue, as well as forward expansion resulting in tissue compression. The deployment of this expansible member may be accompanied by injection of air or fluid to assist in the expansion of the expansible member and tissue compression process. Such an embodiment is described in greater detail in co-pending U.S. patent application Ser. No. 10/718,504, assigned to the assignee of the present application and incorporated herein by reference. [0055] FIGS. 8A through 8G illustrate operation of closure system 10 described above with a symmetrical compression balloon 80 . At the completion of a catheterization procedure, a sheath 100 remains in place as shown in FIG. 8A . Assembly 11 of the closure system 10 is slidably received within the sheath 100 , as shown in FIG. 8B . Assembly 11 is fed through the sheath 100 far enough to guarantee that the distal end of the expansible member 13 is outside the sheath 100 and in the lumen 101 of blood vessel. This may be indicated by marking 19 on the outside of tubular member 12 . Once in place, the expansible member 13 is deployed by pushing the deployment handle 14 forwardly, as in the case of a push type locating mechanism ( FIGS. 2A and 2B ). Locating assembly 11 is then pulled back until expansible member 13 is placed against the distal tip of the sheath 100 . This would be indicated as resistance is felt when assembly 11 is pulled back. The sheath 100 is then slowly removed from the body, and over assembly 11 , and discarded. As shown in FIG. 8C , assembly 11 would be left behind with locating member 13 against vessel wall 102 at the puncture site 103 , inside the vessel, and temporary hemostasis plug 16 remains lodged in the vessel wall at 103 , preventing blood from leaking out. [0056] Referring now to FIG. 8D , the proximal end of assembly 11 is then pushed through the distal end of compression assembly 50 and fed through the lumen of its tubular member 51 until it penetrates seal 52 , and exits the proximal end of assembly 50 . Compression assembly 50 is then guided over tubular member 12 of locating/temporary hemostasis assembly 11 through an opening in skin 104 , through tissue tract 105 , until its distal end 97 is placed at a predetermined distance 106 from the vessel wall 102 and against subcutaneous tissue 98 . This positioning may be indicated by marking 18 on tubular member 12 . The compression balloon is then inflated to its optimum pressure so as to provide targeted micro compression, as shown in FIG. 8E . Tissue compression 107 over the puncture site 103 of the vessel wall 102 can now provide the means for hemostasis. Assembly 11 of the closure device is then contracted and removed from the body through the lumen of the compression assembly 50 , as shown in FIG. 8F . The compression assembly 50 may remain in the body as long as necessary to allow the body's own natural wound healing mechanism to achieve hemostasis. The balloon 80 is then deflated, and the compression assembly 50 is removed, as shown in FIG. 8G . [0057] FIGS. 9A through 9C illustrate another system 110 embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. The system 110 comprises a catheter assembly 120 and an inflation assembly 140 . Catheter assembly 120 has a cross-sectional profile smaller than the sheath 100 . FIG. 9A shows the catheter assembly 120 which comprises a locating/temporary hemostasis mechanism 121 , 124 (and means for deployment) integrated with a compression balloon 126 and a second tubular member 127 for inflating the compression balloon 126 . The catheter assembly 120 includes locating expansible member 121 and means for its deployment and retraction, namely push/pull member 122 and handle assembly 123 . Member 122 exits a proximal end of the first tubular member 125 through seal 131 . Since first tubular member 125 is in communication with blood, seal 131 prevents blood from flowing out. The movement of handle assembly 123 may be limited by the proximal end of the first tubular member 125 and by interference of expansible member 121 with a distal end of tubular member 125 . Movement of plug member 124 and tubular member 125 may be limited by interference of feature 132 with a proximal end of second tubular member 127 and by interference of plug 124 with a distal end of tubular member 127 at feature 130 . [0058] It may be desirable in some embodiments to allow the expansible member 121 and the hemostasis plug 124 to move freely forward in a distal direction when the compression balloon 126 is inflated. Therefore an intermediate position for the relative position of tubular members 125 and 127 may be established before feature 132 interferes with the proximal end of tubular member 127 . In this position the expansible member 121 and the hemostasis plug 124 are deployed and the compression balloon 126 is placed at the desired distance to the vessel wall 102 . This intermediate position may be identifiable by a visual mark or by a mechanical detent as described above. It may also be desirable to design the deployment and contraction mechanism 122 of the expansible member 121 and the temporary hemostasis plug 124 so that the temporary hemostasis plug 124 is deployed first followed by the locating mechanism 121 . When contracting these members, the locating member 121 is retracted within the hemostasis plug 124 first and then the plug 124 is retracted into second tubular member 127 . [0059] Temporary hemostasis plug 124 is at the distal end of the first flexible elongated tubular member 125 . Compression balloon 126 is attached at the distal end of the second flexible tubular member 127 . Second tubular member 127 terminates in flexible inflation tube 128 . Second tubular member 127 is in fluid communication with compression balloon 126 through ports 129 . The two tubular members 125 and 127 may be moveable respect to each other, as shown in FIG. 9A . Expansible member 121 and temporary hemostasis plug 124 may be retracted and housed inside the second tubular member 127 at feature 130 after the compression balloon 126 has been inflated. System 110 may also be designed to have the two tubular members 125 and 127 be fixed relative to each other. In such a case, the inflation process and distal expansion of compression balloon 126 may cause members 121 and 124 to be retracted and removed from the vessel lumen 101 and the vessel wall 102 . FIG. 9B shows inflation assembly 140 which generally comprises a quick connect 141 that connects inflation mechanism 140 to inflation tube 128 of catheter assembly 120 , a pressure relief valve 142 , a stopcock 143 , and a luer lock 144 for attaching syringe 145 . [0060] Operation of system 110 with the sheath 100 still in place involves positioning catheter assembly 120 through the sheath 100 , until a tip of the catheter assembly 120 is outside of the sheath 100 and is in the vessel lumen 101 . As shown in FIG. 9A , this may be indicated by mark 133 on the second tubular member 127 . The first tubular member 125 is moved forward to expose plug 124 . Handle assembly 123 is then moved forward to deploy the expansible member 121 . Catheter assembly 120 is then pulled back until resistance is felt, indicating that expansible member 121 is at the distal end of the sheath 100 . The sheath is then pulled back, and slowly removed from the body, over the entire length of the catheter 120 , leaving expansible member 121 against the inside of the vessel wall 102 , and with hemostasis plug 124 lodged in the puncture site 103 in the vessel wall 102 . The sheath 100 can be discarded. The compression balloon 126 is now located and fixed at a predetermined distance 106 from the vessel wall 102 . [0061] Inflation assembly 140 is then connected to inflation tube 128 via quick connect 141 as illustrated in FIG. 9C . Syringe 145 containing air, saline, other agents (e.g., clot promoting solutions), or a combination thereof is connected to luer lock 144 . With stopcock 143 in inflation/deflation position the balloon 126 is inflated to the desired inflation pressure, causing radial and axial expansion of the balloon 126 and causing subcutaneous tissue compression 107 against the puncture site 103 , overcoming the blood pressure and producing hemostasis. The inflation process is complete when air or fluid starts to exit from the pressure relief valve 142 . Stopcock 143 is turned to hold position allowing the pressure to be maintained inside compression balloon 126 . Handle assembly 123 is then manipulated to sequentially retract the locating member 121 first and then the temporary hemostasis plug 124 . The compression balloon 126 is allowed to remain inflated for a period of time against the subcutaneous tissue 98 . Once the desired period of compression time is elapsed, stopcock 143 is put in the inflation/deflation position. The syringe 145 can be used to facilitate removal of the medium from the compression balloon 126 and furthermore collapse the balloon 126 around the tubular member 127 . Catheter assembly 120 is then removed from the body. [0062] FIG. 10 illustrates yet another system 110 ′ embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. This is an integrated, unitary structure 120 , containing all the working elements as discussed above with reference to FIGS. 9A through 9C . In this embodiment, the inflation assembly 140 ′ of system 110 ′ has a profile that is substantially greater than the sheath 100 . As such, the second flexible elongated tubular member 127 is made of sufficient length to allow for complete removal of the sheath 100 from the body when the locating expansible member 121 and temporary hemostasis plug 124 are deployed. The sheath 100 stays with the assembly 120 until hemostasis is achieved and the system 110 ′ is removed. [0063] FIGS. 11A through 11C illustrate yet another system 200 embodiment for hemostasis of a puncture site in a body lumen constructed in accordance with the principles of the present invention. This is also an integrated structure, including several of the working elements discussed above with reference to FIGS. 9A through 9C . For example, the functions of locating expansible member 151 , push/pull member 152 , temporary hemostasis plug 153 , compression balloon 154 , seal 155 , and handle assembly 156 are similar to those described above. As depicted in FIG. 11C , the pumping mechanism includes a compression seal 157 and a pump handle 158 . The pump assembly 157 , 158 compresses the air in piston 159 to inflate compression balloon 154 . Balloon 154 is in fluid communication with 159 through opening 160 , as depicted in FIG. 11B . System 200 has a cross-sectional profile that is smaller than the inside diameter of the sheath 100 being used. Therefore the sheath 100 can completely slide off over the system 200 when the locating expansible member 151 and temporary hemostasis plug 153 have been deployed and are placed in the vessel appropriately. [0064] Although certain exemplary embodiments and methods have been described in some detail, for clarity of understanding and by way of example, it will be apparent from the foregoing disclosure to those skilled in the art that variations, modifications, changes, and adaptations of such embodiments and methods may be made without departing from the true spirit and scope of the invention. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.

The present invention provides devices, systems, and methods for percutaneously sealing a puncture site in tissue tracts and vessels in human or animal bodies. One system includes a locating assembly that is used to locate the puncture site and can also provide temporary hemostasis when the system is used for closing a vessel puncture. The system also includes a compression assembly comprising a tubular member with a balloon on a distal end thereof. This balloon is at a fixed distance from the locator tip which locates the balloon outside the vessel wall at a predetermined distance. Inflation of this balloon causes forward elongation of the balloon which compresses subcutaneous tissue between the distal tip of the balloon and the vessel wall. This tissue compression against the puncture site is the mechanism that provides hemostasis.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from U.S. Provisional Application Ser. No. 61/779393, filed 13 Mar. 2013, the disclosure of which is incorporated by reference in its/their entirety herein. FIELD OF THE DISCLOSURE [0002] This disclosure relates to certain polythioether polymers, compositions which are radiation curable to polythioether polymers, and seals and sealants comprising same. SUMMARY OF THE DISCLOSURE [0003] Briefly, the present disclosure provides a composition which is radiation curable to a polythioether polymer, comprising: a) at least one dithiol monomer; b) at least one diene monomer; c) at least one multifunctional monomer having at least three ethenyl groups; and d) at least one photoinitiator. In some embodiments the composition may additionally comprise e) at least one epoxy resin. In some embodiments, the multifunctional monomer has three ethenyl groups. [0004] In another aspect, the present disclosure provides a composition which is radiation curable to a polythioether polymer, comprising: f) at least one dithiol monomer; g) at least one diene monomer; h) at least one multifunctional monomer having at least three thiol groups; and i) at least one photoinitiator. In some embodiments the composition may additionally comprise j) at least one epoxy resin. In some embodiments, the multifunctional monomer has three thiol groups. [0005] In another aspect, the present disclosure provides a composition which is radiation curable to a polythioether polymer, comprising: k) at least one thiol terminated polythioether polymer; l) at least one multifunctional monomer having at least three ethenyl groups; and m) at least one photoinitiator. In some embodiments, the thiol terminated polythioether polymer comprises pendent hydroxide groups. In some embodiments, the multifunctional monomer has three ethenyl groups. [0006] In some embodiments, the compositions described herein may additionally comprise a filler, in some embodiments a nanoparticle filler. In some embodiments, the composition may additionally comprise calcium carbonate. In some embodiments, the composition may additionally comprise nanoparticle calcium carbonate. [0007] In some embodiments, the compositions described herein visibly change color upon cure. In some embodiments, the compositions described herein are curable by an actinic light source. In some embodiments, the compositions described herein are curable by a blue light source. In some embodiments, the compositions described herein are curable by a UV light source. In another aspect, the present disclosure provides a sealant comprising any of the compositions described herein. In some embodiments, the sealant is transparent. In some embodiments, the sealant is translucent. [0008] In another aspect, the present disclosure provides a polythioether polymer obtained by radiation cure of any the radiation curable compositions described herein. In some embodiments, the polythioether polymer has a Tg less than −55° C. In some embodiments, the polythioether polymer exhibits high jet fuel resistence characterized by a volume swell of less than 30% and a weight gain of less than 20% when measured according to Society of Automotive Engineers (SAE) International Standard AS5127/1. [0009] In another aspect, the present disclosure provides a seal comprising any of the polythioether polymers described herein. In some embodiments, the seal is transparent. In some embodiments, the seal is translucent. DETAILED DESCRIPTION [0010] The present disclosure relates polythioether sealants. In some embodiments, the present disclosure relates to mercaptan based polythioether sealants containing radical photoinitiators. In some embodiments, the present disclosure relates to sealants that may be cured on demand in a one-step process in seconds by UV/LED radiation sources. In some embodiments, the sealants include fillers. In some embodiments, the sealants exclude fillers. In some embodiments, the sealant formulation contains a mercaptan based monomer (such as a dithiol) or oligomer (such as a linear polythioether or polysulfide), a divinylether, a crosslinker (such as triallylcyanurate), and a radical photoinitiator (such as Irgacure 819). By exposure to light around 450 nm, these compounds are curable in seconds to a rubber with low glass transition temperature (typically less than −55 ° C. and in many embodiments around −60 ° C.) and high fuel resistance properties. Use of these formulations has the potential to accelerate manufacturing. [0011] In some embodiments, the sealant according to the present disclosure can simultaneously provide a long application life and cured on demand In some embodiments, the sealant according to the present disclosure exhibit favorable solvent and fuel resistance properties. In some embodiments, the sealant according to the present disclosure exhibit favorable thermal resistance properties. [0012] In some embodiments, the user applies the sealant according to the present disclosure as a single-component liquid formulation to the structure requiring sealing. In some embodiments, the user applies the sealant according to the present disclosure as a multi-component liquid formulation to the structure requiring sealing. In some embodiments, the sealant remains liquid and usable until the user applies an external source of electromagnetic (EM) radiation. Any suitable source of EM radiation can be used, most typically selected from UV, visible and IR radiation. Upon application of the external EM radiation the liquid sealant then cures or crosslinks. In some embodiments, the sealant cures or crosslinks to an at least partially elastomeric solid in less than one minute. Objects and advantages of this disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure. EXAMPLES [0013] Unless otherwise noted, all reagents were obtained or are available from Sigma-Aldrich Company, St. Louis, Miss., or may be synthesized by known methods. Unless otherwise reported, all ratios are by weight percent. [0014] The following abbreviations are used to describe the examples: ° C.: degrees Centigrade cm: centimeter LED: light emitting diode mm: millimeter nm: nanometer T g : glass transition temperature UV: ultraviolet W: Watt Materials [0023] Abbreviations for the reagents used in the examples are as follows: [0024] A-200: A hydrophilic fumed silica, obtained under the trade designation “AEROSIL 200” from Evonik Industries AG, Essen, Germany. [0025] A-7200: A methacrylate functionalized fumed silica, obtained under the trade designation “AEROSIL 7200” from Evonik Industries AG. [0026] CPQ: Camphorquinone. [0027] DMDO: 1,8-Dimercapto-3,6-dioxaoctane, obtained from Arkena, Inc., King of Prussia, Pa. [0028] DSW: An aluminosilicate clay, obtained under the trade designation “DRAGONITE SELECT WHITE” from Applied Minerals, Inc., New York, N.Y. [0029] DVE-2: Diethyleneglycol divinyl ether, obtained from BASF Corp., Florham Park, N.J. [0030] DVE-3: Triethyleneglycol divinylether, obtained under the trade designation “RAPI-CURE DVE-3” from Ashland Specialty Ingredients, Wilmington, Del. [0031] E-8220: A diglycidylether of bisphenol F, obtained under the trade designation “EPALLOY 8220” from Emerald Performance Materials, LLC, Cuyahoga Falls, Ohio. [0032] EDMAB: Ethyl 4-(dimethylamino) benzoate. [0033] I-651: 2,2-Dimethoxy-1,2-diphenylethan-l-one, obtained under the trade designation “IRGACURE 651” from BASF Corp. [0034] I-819: Phenylbis(2,4,6-trimethylbenzoyl)phosphine Oxide, obtained under the trade designation “IRGACURE 819” from BASF Corp. [0035] LP-33: A liquid polysulfide polymer, obtained under the trade designation “THIOKOL LP-33” from Toray Fine Chemicals Co., Ltd., Urayasu, Japan. [0036] MPMDMS: 3-mercaptopropyl methyl dimethoxysilane, obtained from Gelest, Inc., Morrisville, Pa. [0037] NCC: 70-100 nm calcium carbonate, obtained under the trade designation “SOCAL 31” from Solvay Chemicals, Inc., Houston, Tex. [0038] PTE: A liquid polythioether polymer prepared as follows. Into a 5 liter round bottom flask equipped with an air driven stirrer, thermometer, and a condenser, was added 167.1 grams (0.51 mol) E-8220 and 1641 grams (9.0 mol) DMDO. After several minutes of stirring the mixture exothermed to 45° C. After another 30 minutes, the temperature of the flask was increased 75° C. and a mixture of 1428.1 grams (7.1 mol) DVE-3, 50.7 grams (0.2 mol) TAC and 13.1 grams (0.07 mol) VAZO-67 was added drop wise. The reaction proceeded substantially to completion affording 3,300 grams of polythioether polymer. [0039] TAC: Triallylcyanurate, obtained from Sartomer, Inc., Exton, Pa. [0040] TPO-L: Diphenyl(2,4,6-trimethylbenzoyl)-phosphinic acid ethyl ester, obtained under the trade designation “LUCERIN TPO-L” from BASF Corp. [0041] VAZO-67: 2,2′-azobis(2-methylbutyronitrile, obtained under the trade designation “VAZO-67” from E.I. du Dupont de Nemours and Company, Wilmington, Del. Example 1 [0042] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 7.055 grams DMDO, 5.252 grams DVE-2 and 0.914 grams TAC at 21° C. To this was added 0.132 grams I-819. The vial was then sealed and placed on a laboratory roller mill for 10 minutes until the I-819 had dissolved. Example 2 [0043] A curable polythioether composition was prepared as generally described in Example 1, wherein, after the resin and initiator were dissolved, 2.003 grams NCC was homogeneously dispersed in the composition by means of a high speed mixer for 1 minute. Example 3 [0044] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 5.000 grams PTE and 0.295 grams TAC at 21° C. To this was added 0.053 grams I-819. The vial was then sealed and placed on the laboratory roller mill for 16 hours until the I-819 had dissolved. Example 4 [0045] A curable polythioether composition was prepared as generally described in Example 1, wherein, after the resin and initiator were dissolved, 0.802 grams NCC was homogeneously dispersed in the composition by means of a high speed mixer for 1 minute. Example 5 [0046] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 5.000 grams LP-33 and 0.750 grams TAC at 21° C. To this was added 0.058 grams I-819. The vial was then sealed and placed on the laboratory roller mill for 16 hours until the I-819 had dissolved. Example 6 [0047] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 2.000 grams PTE and 0.118 grams TAC at 21° C. To this was added 0.021 grams TPO-L. The vial was then sealed and placed on the laboratory roller mill for 30 minutes until the TPO-L had dissolved. Example 7 [0048] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 2.000 grams PTE and 0.118 grams TAC at 21° C. To this was added 0.021 grams I-651. The vial was then sealed and placed on the laboratory roller mill for 30 minutes until the I-651 had dissolved. Example 8 [0049] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 2.000 grams PTE and 0.118 grams TAC at 21° C. To this was added 0.021 grams CPQ and 0.021 grams EDMAB. The vial was then sealed and placed on the laboratory roller mill for 16 hours until the CPQ and EDMAB had dissolved. Example 9 [0050] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 5.000 grams DMDO, 3.108 grams DVE-2, 1.295 grams TAC and 0.410 grams MPMDMS at 21° C. To this was added 0.094 grams I-819, the vial then sealed and placed on a laboratory roller mill for 10 minutes until the I-819 had dissolved. 0.991 grams A-200 was then homogeneously dispersed in the composition by means of a high speed mixer for 1 minute. Example 10 [0051] A curable polythioether composition was prepared as generally described in Example 9, wherein the amount of A-200 was increased to 1.487 grams. Example 11 [0052] A curable polythioether composition was prepared as generally described in Example 9, wherein the amount of A-200 was increased to 1.982 grams. Example 12 [0053] A curable polythioether composition was prepared as generally described in Example 9, wherein the A-200 was substituted with an equal amount of A-7200. Example 13 [0054] A curable polythioether composition was prepared as generally described in Example 10, wherein the A-200 was substituted with an equal amount of A-7200. Example 14 [0055] A curable polythioether composition was prepared as generally described in Example 11, wherein the A-200 was substituted with an equal amount of A-7200. Example 15 [0056] A curable polythioether composition was prepared as generally described in Example 9, wherein the A-200 was substituted with an equal amount of DSW. Example 16 [0057] A curable polythioether composition was prepared as generally described in Example 10, wherein the A-200 was substituted with an equal amount of DSW. Example 17 [0058] A curable polythioether composition was prepared as generally described in Example 11, wherein the A-200 was substituted with an equal amount of DSW. Example 18 [0059] A curable polythioether composition was prepared as generally described in Example 17, wherein the amount of DSW was increased to 2.973 grams. Example 19 [0060] A curable polythioether composition was prepared as follows. A 40 ml. amber glass vial was charged with 7.000 grams DMDO, 4.349 grams DVE-2 and 1.812 grams TAC at 21° C. To this was added 0.132 grams I-819. The vial was then sealed and placed on a laboratory roller mill for 10 minutes until the I-819 had dissolved. Example 20 [0061] A curable polythioether composition was prepared as generally described in Example 1, wherein the amount of I-819 was increased to 0.264 grams. Example 21 [0062] A curable polythioether composition was prepared as generally described in Example 20, wherein after the resin and initiator were dissolved, 2.023 grams NCC was homogeneously dispersed in the composition by means of a high speed mixer for 1 minute. Example 22 [0063] A curable polythioether composition was prepared as generally described in Example 3, wherein the amount of I-819 was increased to 0.106 grams. Example 23 [0064] A curable polythioether composition was prepared as generally described in Example 22, wherein after the resin and initiator were dissolved, 2.023 grams NCC was homogeneously dispersed in the composition by means of a high speed mixer for 1 minute. Curing Process [0065] The following actinic light sources were used to cure the Examples and Comparatives: [0066] LC-200: A broad range UV spot lamp, model “LIGHTNINGCURE 200 UV SPOT LIGHT SOURCE”, obtained from Hamamatsu Photonics, K.K., Hamamatsu City, Japan. Distance between bulb and sample surface distance was 7.62 cm. [0067] NC-385: A 385 nm LED, constructed from LED chips, type “NCSUO34B(T), obtained from Nichia Corporation, Tokushima, Japan. Distance between bulb and sample surface distance was 1.27 cm. [0068] STARFIRE MAX: A 395 nm lamp, model “STARFIRE MAX”, obtained from Phoseon Technology, Hillsboro, Oreg. Distance between bulb and sample surface distance was 2.54 cm. [0069] 3M-2500: A 400-500 nm lamp, model “3M DENTAL 2500”, obtained from 3M Company. Distance between bulb and sample surface distance was 0.635 cm. [0070] CF2000: A 455 nm LED, model “CF2000”, obtained from Clearstone Technologies, Inc., Minneapolis, Minn. Distance between bulb and sample surface distance was 0.635 cm. [0071] FUSION H: A broad wavelength 200-600 nm mercury UV bulb, obtained from Fusion UV Systems, Inc., Gaithersburg, Md. Distance between bulb and sample surface distance was 5.30 cm. Test Methods [0072] The following test methods were used to evaluate the cured samples: [0073] Shore A Hardness: Measured using a model “1600” hardness gauge, obtained from Rex Gauge Company, Inc., Buffalo Grove, Ill. [0074] T g : Measured using a model “DSC Q2000” differential scanning calorimeter, obtained from TA Instruments, New Castle, Del. [0075] Jet Fuel Resistance: Measured according to Society of Automotive Engineers (SAE) International Standard AS5127/1, wherein samples were immersed in Jet Reference Fluid Type 1 (JRF1) for 7 days at 60° C., after which % Swell, % Weight Gain and % Weight Loss were determined JRF1 composition was, by % volume, 38% toluene, 34% cyclohexane, 38% isooctane and 1% tertiary dibutyl disulfide. [0076] Color Change: Measured before and after curing using a model “MINISCAN XE PLUS D/8S” colorimeter, in mode D65/10*, obtained from Hunter Associates Laboratory, Inc., Reston, Va. [0077] Samples were poured into either nominally a 2 by 2 cm or a 2 by 4 cm silicone rubber mold of various heights, at 21° C., and cured by exposure to one of the actinic light sources described above. Resultant thickness, Shore A hardness and T g of the samples were measured. Results listed in Table represent the average of triplicate samples for thickness and Shore A hardness, and duplicate measurements for T g . Selected examples were also subjected to the Jet Fuel Resistance test, and are reported in Table 2. Color change measurements, as an average of three reading and expressed as L*a*b* and ΔE values, are listed in Table 3. [0078] Examples 1, 3, 5-20, and 22 remained translucent at the cured thickness listed in Table 1. [0000] TABLE 1 Cure Shore A Time Thickness Hard- T g Sample Light Source (seconds) (mm) ness (° C.) Example 1 LC-200 60 2.63 57.5 −61 Example 1 STARFIRE MAX 60 2.14 57.5 −61 Example 1 3M-2500 60 2.31 61.0 −61 Example 1 CF2000 5 2.63 57.5 −61 Example 1 CF2000 10 2.14 57.5 −61 Example 1 CF2000 15 2.31 61.0 −61 Example 1 CF2000 20 2.00 55.5 −62 Example 2 LC-200 60 1.83 66.0 −62 Example 2 STARFIRE MAX 60 2.43 67.0 −62 Example 2 NC-385 60 2.25 65.0 −62 Example 2 3M-2500 60 1.56 70.0 −62 Example 2 CF2000 10 4.20 63.0 −62 Example 3 LC-200 60 2.08 44.0 −59 Example 3 STARFIRE MAX 60 2.00 47.0 −59 Example 3 3M-2500 60 2.18 43.0 −59 Example 3 CF2000 5 2.08 44.0 −59 Example 3 CF2000 10 2.00 47.0 −59 Example 3 CF2000 15 2.18 43.0 −59 Example 3 CF2000 20 2.14 48.0 −58 Example 4 STARFIRE MAX 60 1.84 44.0 −59 Example 4 3M-2500 60 2.02 55.0 −59 Example 5 STARFIRE MAX 60 2.15 60.0 −59 Example 6 LC-200 300 2.30 40.0 −60 Example 6 3M-2500 600 1.30 55.0 −59 Example 6 CF2000 300 2.60 45.0 −60 Example 7 FUSION H 10 1.90 46.0 −60 Example 8 3M-2500 900 1.40 54.0 −60 Example 9 CF2000 30 16.36 72.0 −58 Example 10 CF2000 30 3.21 50.0 −58 Example 11 CF2000 30 Not 55.0 −57 Measured Example 12 CF2000 30 4.21 46.0 −58 Example 13 CF2000 30 4.20 54.0 −58 Example 14 CF2000 30 1.91 60.0 −57 Example 15 CF2000 30 4.60 41.0 −58 Example 16 CF2000 30 4.67 41.0 −58 Example 17 CF2000 30 4.17 45.0 −60 Example 18 CF2000 30 3.54 46.0 −60 Example 19 CF2000 30 44.15 57.5 −56 [0000] TABLE 2 Cure % % Time Weight Weight Sample Light Source (seconds) % Swell Gain Loss Example 1 STARFIRE MAX 60 22.5 16.5 3.4 Example 1 CF2000 10 21.7 15.6 3.8 Example 2 NC-385 60 21.5 14.6 2.9 Example 3 LC-200 60 20.8 13.9 6.9 Example 3 CF2000 10 21.5 14.8 6.1 Example 4 STARFIRE MAX 60 22.1 14.5 5.2 Example 10 CF2000 30 19.6 12.2 2.8 Example 13 CF2000 30 15.6 12.9 2.9 Example 16 CF2000 30 15.9 11.0 4.3 [0000] TABLE 3 Example Curing Step L* a* b* ΔE 20 Before 88.04 −10.89 23.92 17.09 After 88.02 −3.95 8.30 21 Before 85.57 −11.35 19.35 16.31 After 83.84 −4.44 4.68 22 Before 88.35 −10.27 25.67 16.16 After 86.46 −4.11 10.85 23 Before 85.58 −10.22 21.67 15.07 After 84.75 −4.42 7.79

Certain polythioether polymers are presented, as well as compositions which are radiation curable to polythioether polymers and seals and sealants comprising same. The compositions radiation curable to polythioether polymers include those comprising: a) at least one dithiol monomer; b) at least one diene monomer; c) at least one multifunctional monomer having at least three ethenyl groups; and d) at least one photoinitiator. In another aspect, the compositions radiation curable to polythioether polymers include those comprising: f) at least one dithiol monomer; g) at least one diene monomer; h) at least one multifunctional monomer having at least three thiol groups; and i) at least one photoinitiator. In another aspect, the compositions radiation curable to poly-thioether polymers include those comprising: k) at least one thiol terminated polythioether polymer; l) at least one multifunctional monomer having at least three ethenyl groups; and m) at least one photoinitiator.

BACKGROUND OF THE INVENTION [0001] This application relates to the use of an insert in a terminal to guide and align multiple wires that are to be secured within the terminal. [0002] Wires are utilized in any number of applications in the prior art. In one common application, multiple wires are brought into a barrel or holding area on an electrical terminal lug. The terminal lug may be of the sort having a generally flat surface with an aperture to make a connection to another component. The barrel may be cylindrical, but may also be other shapes. [0003] In the prior art, the multiple wires are each stripped at a forward end, and then moved into the lug of the terminal. The lug may then be crimped to lock the wires in place. [0004] There are challenges with the prior art, in that it is sometimes difficult to move multiple wires into the barrel. Sometimes it is necessary to force the wires into the barrel, and thus the assembly is complex. In addition, it is often the case that un-insulated sections of the wire extend away from the barrel, which is also somewhat undesirable. SUMMARY OF THE INVENTION [0005] In the disclosed embodiment of this invention, a barrel in a terminal lug receives a spacer which defines spaces to receive portions of multiple wires. The spacer aligns and positions the wires within the barrel, such that assembly is simplified. [0006] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 shows a prior art terminal connection. [0008] FIG. 2A is an exploded view of the inventive connection. [0009] FIG. 2B shows an insert. [0010] FIG. 2C shows a cross-section through the assembled components. [0011] FIG. 3A shows a final step in the connection. [0012] FIG. 3B is a view similar to FIG. 2C , but after the final step has occurred. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0013] FIG. 1 shows a prior art connection 20 . Connection 20 includes a barrel 22 extending to a face 26 having an aperture 24 . Elements 22 , 24 , and 26 form an item known as a terminal lug. As known, the aperture 24 is used to make an electrical connection with another component. Multiple wires 28 and 30 have exposed forward portions 32 where insulation has been removed. These forward portions 32 must be forced into the barrel 22 . It is necessary that the combined size of the forward portions 32 be approximately the same as the size of the barrel 22 such that when the barrel 22 is crimped, the forward portions 32 are captured. On the other hand, by making the combined forward portions 32 approximately the same size as the lug, it becomes difficult to move the wires into the lug for assembly. In addition, as can be appreciated from FIG. 1 , the forward portions 32 extend un-insulated away from the barrel 22 , which is undesirable. [0014] FIG. 2A shows the inventive connection 40 . The terminal lug 22 , 26 , and 24 is generally as known in the prior art, as are the wires 28 and 30 . The forward portions 42 of the wires are moved into an insert 44 , and its spaces 46 . Separator portions 48 are formed between the guiding spaces 46 . [0015] As shown in FIG. 2B , the guiding spaces 46 with the separation portions 48 may be generally symmetrical or they may be asymmetric to accommodate varying numbers and sizes of wires. The sizes of the spaces 46 , and the portions 48 , may be selected to accommodate a particular sized wire, and to be received within a particular sized lug. [0016] As shown in FIG. 2C , the components may be easily assembled within the interior of the barrel 22 . [0017] As shown in FIG. 3A , the lug may now be crimped to be flattened as shown at 60 . As can also be appreciated from FIG. 3B , when the crimping occurs, the insert may deform as well as the barrel 22 , and thus the forward portions of the wires 28 and 30 are securely captured within the barrel 22 . [0018] The insert 44 may be formed of copper or other material that provides good conductivity and is also deformable. [0019] Of course, more than two wires, and various sized wires, can be utilized. The wires may be of similar sizes, as shown, or different sizes. Also, while crimping is shown as the way the wires are secured, other methods such as brazing or soldering can be used. [0020] Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

An electrical connection for securing multiple wires within an interior of an electrical connector barrel includes the use of a spacer which is received within the barrel, and which includes guiding spaces to position the plurality of wires.

This application is a continuation of application Ser. No. 14/184,662 filed Feb. 19, 2014 and claims priority from my provisional application 61850566 filed Feb. 20, 2013 which is hereby incorporated by reference. BACKGROUND I invented a ladder leveler that provides adjustable extensions to ladder legs, U.S. Pat. No. 5,678,656. That leveler is shown in FIGS. 1 and 2 . The leveler includes an outer housing 41 secured with fastening bolts 57 to an outer ladder rail 29 which holds ladder rungs 23 . It includes a leg extension 71 that is movable within a channel 43 in the outer housing 41 from a retracted position to an extended position. It includes a positive locking engagement system including a pawl 73 mounted on a pivot pin 79 and biased into engagement by a pawl spring 81 . The pawl engages ratchet teeth 49 on a toothed ratchet bar 47 held in place by fasteners 51 in a recess 45 . The greater the force applied to the ladder rail 29 , the greater the force applied to the locking engagement between the outer housing 41 and the leg extension 71 . A release lever 75 on the pawl 73 releases the pawl when activated by hand. A safety bar (shown in FIG. 2 without a reference numeral) extends from the center of the shaft of a bolt 33 that is bolted to a support foot 27 to the pawl 73 , contacting the pawl close to its pivot hole 77 , such that force applied to the support foot 27 presses the safety bar against the pawl 73 and locks the pawl in position. The support foot 27 is secured to the leg extension 71 with the securing bolt 33 which acts as a hinge pin by passing through an oblong securing bolt aperture in the leg extension, and is held in place with a securing nut 35 . The support foot 27 includes a rubber friction pad tread 31 . The leveler also includes a retraction spring 53 coupled at one end to the outer housing at a spring fastener 55 and at the other end to the leg extension 71 . The retraction spring continually applies an upward biasing force on the leg extension. To facilitate the extension and retraction of the extension leg 71 into and out of the outer housing 41 , a foot pedal 101 is secured to the front portion of the extension leg 71 with a foot pedal pivot pin 103 . Pressing on the pedal opposes the force of the retraction spring 53 . SUMMARY OF THE INVENTION The invention provides improvements to the leg extension of my prior ladder leveler and, more generally, improvements to ladder legs. In one aspect, the invention is a ladder leg with a nailable, pivoting shoe, comprising a ladder leg having a bottom end with a pivotable structure at the bottom end; pivotably coupled to the pivotable structure, a ladder shoe having a planar bottom surface, the bottom surface being a surface of a support structure of the ladder shoe adapted to apply weight of the ladder to a planar surface on which the ladder rests when erected; at least one hole in the support structure, the hole passing through the support structure perpendicular to the planar bottom surface of the ladder shoe; and the hole having a minimum diameter of at least 1/16 inch and no part large enough to allow passage of a ⅜ inch sphere. The hole may be round or a slot. The support structure may include a metal portion and a rubber portion and the rubber portion forming the planar bottom surface of the ladder shoe, in which case the at least one hole in the support structure passes through the metal portion and aligns with a hole in the rubber portion. The hole in the rubber portion may be smaller than the hole in the metal portion with which it is aligned so that the hole in the rubber portion is enlarged by entry of a penetrating object that is smaller than the hole in the metal portion but larger than the hole in the rubber portion and the penetrating object is thereby gripped by the rubber portion. The planar bottom surface of the ladder shoe may comprises multiple, discontinuous bottom surfaces in a single plane, the lowest parts of the rubber tread as shown in the figures. The support structure may include, on a top surface surrounding the hole, a raised edge that supports a head of a nail inserted into the hole such that the head can be easily engaged by a forked claw for removing the nail. The leg may be an extendable and adjustable leg. In another aspect, the invention is a retractable ladder leveler with improved foot operable control, comprising an outer housing mountable on a bottom end of a ladder and, slidably coupled to the outer housing, an adjustable ladder leg extension having a direction of extension and an opposite direction of retraction. The outer housing and the leg extension together present a shoe-contactable boundary around the leveler defined as the limit of locations on or near the outer housing and the leg extension that can be contacted by a sphere of 7½ inches diameter (the typical curvature of the inside or outside ball of the foot of a typical shoe). A spring is coupled to the leg extension and to the outer housing. It urges the leg extension to slide in the direction of retraction. A retaining pawl releaseably connects the outer housing and the leg extension. When the pawl is engaged, it holds the leg extension from sliding in the direction of retraction. The retaining pawl has a release lever. A foot pedal is coupled at its proximal end via a pivot to the leg extension. The pivot and the foot pedal are configured so that, when pivoted into an action position, the foot pedal presents a foot engagable surface that is perpendicular to the direction of extension and transmits to the leg extension a force applied by a foot in opposition to the spring, causing the extension to extend. The improvement is that the pivot and the foot pedal are further configured so that, when the foot pedal is pivoted into a non-action position, the distal end of the foot pedal protrudes to form a foot engageable ledge perpendicular to and extending at least ⅛ inch beyond the shoe-contactable boundary so that a human's shoe moving in the direction of extension along the outer housing and the leg extension will catch the foot pedal and cause it to pivot into an action position. For better functionality, the distal end of the foot pedal may protrude at least 5/16 inch beyond the outer shoe-contactable boundary, preferably 9/16 inch beyond the shoe-contactable boundary. The release lever may also have a distal end protruding at least ¼ inch beyond the outer shoe-contactable boundary of the outer housing and the leg extension so that a human's shoe moving in the direction of extension along the outer housing and the leg extension will catch the release lever to release the pawl. The distal end of the release lever may have a lip extending in the direction of retraction so that a shoe can more easily catch and engage the release lever. For better functionality, the distal end of the release lever may protrude at least ⅜ inch beyond the outer shoe-contactable boundary, preferably 9/16 inch beyond the shoe-contactable boundary. In another aspect, the invention is an extendable and adjustable ladder leg with an improved shoe with a claw, comprising an extendable and adjustable ladder leg extension having a longitudinal direction of extension and an opposite longitudinal direction of retraction and having a shoe hingedly coupled to a distal end of the leg extension in a way that gives the shoe a range of hinging motion with respect to the hinge and a range of longitudinal motion with respect to the leg extension. The shoe has a hinge pin that forms a hinge axis, as well as a first end that is most distant from the hinge axis, and a second end that is most distant from the first end. The adjustable ladder leg has a safety bar slidably mounted on the leg extension and coupled to the shoe such that the safety bar moves in the direction of retraction with respect to the leg extension when the shoe moves in the direction of retraction with respect to the leg extension, the safety bar thereby preventing release of a release mechanism that, when activated, releases the leg extension to move in the direction of retraction. The improvement comprises the shoe having a toothed claw on at least one of the first end or the second end; the shoe including cut-outs that allow the shoe to hinge 180 degrees about the hinge axis when the extension leg is fully retracted; and the shoe including retaining surfaces that contact parts of the leg extension and retain the claw in a fully hinged position when force is applied along the leg extension in the direction of retraction, urging the claw against an object which the claw grips. In addition, the shoe and leg extension parts are configured such that, when the shoe is in a fully hinged position and force is applied along the leg extension in the direction of retraction, the shoe can move toward the leg extension to actuate the safety bar and thereby prevent activation of the release mechanism. The retaining surfaces that contact parts of the leg extension and retain the shoe in a fully hinged position may comprise part of a circumference of each of two triangular holes, one in each of two sidewalls of the shoe, which retaining surfaces contact a hinge pin coupled to the leg extension. The triangular holes may each include at least one slope in its circumference which slope is a retaining surface that applies a lateral force to the shoe via contact with the hinge pin when weight is applied to the leg extension while the ladder leg is in an erected position and the shoe is in a fully hinged position. The retaining surfaces that contact a part of the leg extension and retain the shoe in a fully hinged position may comprise an upper side of a support base of the shoe which upper side contacts a lower corner of the leg extension to retain the shoe in a fully hinged position. In this case, the retaining surfaces also comprise part of a circumference of each of two holes, one in each of two sidewalls of the shoe, which holes, when the shoe is in a fully hinged position, are longer in the longitudinal direction than a diameter of the hinge pin, such that the shoe can move in the direction of retraction with respect to the leg extension after the shoe is in a fully hinged position and thereby place the retaining surfaces in position to retain the shoe in a fully hinged position and simultaneously actuate the safety bar. In another aspect, the invention is a ladder leg with an improved shoe with a claw, comprising a ladder leg having a longitudinal direction along the leg, having a bottom end, and having a shoe hingedly coupled to the bottom end of the leg in a way that gives the shoe a range of hinging motion with respect to the hinge and a range of longitudinal motion with respect to the leg, the shoe having a hinge pin that forms a hinge axis, a first end that is most distant from the hinge axis, and a second end that is most distant from the first end. The shoe has a toothed claw on at least one of the first end or the second end. The shoe and bottom end of the leg are configured to allow the shoe to hinge about the hinge axis to a point where the shoe base is parallel to the leg. The improvement comprises: the shoe and leg each have retaining surfaces that contact each other and retain the shoe in a fully hinged position, which retaining surfaces comprise: an upper side of a support base of the shoe which upper side contacts a lower corner of the leg to retain the shoe in a fully hinged position; and a part of a circumference of each of two holes, one in each of two sidewalls of the shoe, which holes, when the shoe is in a fully hinged position, are longer in the longitudinal direction than a diameter of the hinge pin, and the part of the circumference of each of two holes contacting the hinge pin retain the shoe in a fully hinged position. In this event, the shoe can move in the direction of retraction with respect to the leg after the shoe is in a fully hinged position and thereby place the retaining surfaces in position to retain the shoe in a fully hinged position. The two holes may each be triangular in shape. BRIEF DESCRIPTION OF THE FIGURES FIGS. 1 and 2 show the prior art ladder leveler with an adjustable extendable leg. FIG. 3 shows the hole in the shoe for nailing. FIG. 4 shows two nails through the holes and through aligned holes in the rubber tread portion of the shoe. FIG. 5 shows the conical shaped raised metal around the hole to facilitate removing the nail. FIG. 6 shows the shoe with a triangular hole rotated 90 degrees but hanging low off the leg of the ladder. FIG. 7 shows the shoe still rotated 90 degrees but now pushed up from below so that the leg of the ladder extends lower than the triangular hole. FIG. 8 shows the lower foot pedal in a folded position and the upper release lever, each extending outward enough to be operable with a person's foot (shoe). FIG. 9 shows the lower foot pedal in the unfolded position for extending the leg. DETAILED DESCRIPTION Ladder Shoe with Fastener Holes As shown in FIGS. 3 and 4 , fastener holes 201 in the ladder shoe allow nails or screws or other fasteners to be inserted into dirt or wood or other material on which the ladder is erected to provide extra grip. Instead of holes, slots may be placed in the shoe. Most ladder shoes include a rubber tread 31 below a metal support structure 27 . The tread may also have aligned holes so the nails can pass through both the metal structure and the rubber tread as shown in FIG. 4 . These holes in both the metal and the rubber tread make the shoe lighter, which is always a design advantage for ladders. The holes are located near the ends of the shoe, large enough to slide a nail or similar, sharp or narrow, or thin metal or plastic piece through the hole or holes to penetrate a slippery surface, thereby providing additional non-slip features to the bottom surface of the shoe. The shoe will preferably include a claw on each end as shown in FIGS. 3 and 4 , and the holes are near the claws. The hole or slot in the metal portion of the shoe can be the same size or slightly larger than the penetrating object, (i.e. 16d framing nail) to minimize any friction between the two objects, but the rubber tread underneath the metal portion can be slightly smaller than the penetrating object so that the rubber tread grips the penetrating object tightly, thereby minimizing the chance of it sliding back up and out too easily. The penetrating object may be slid into the hole or slot when a ladder or leveler is set up on a slippery surface, as an added safety measure. An example would be setting up a ladder on a mossy deck. A nail can be slid through the leveler shoe hole and in between the grooves in between deck boards. A 16d framing nail, or sinker, is the most common nail found on a construction site, used for general framing, temporary scaffolding, saw horses, etc. A 16d framing nail placed in a slightly larger hole in the metal, a slightly smaller hole in the tread make the best combination of holes and penetrating devices. Additionally, as shown in FIG. 5 , the hole or holes in the shoe bottom can also have an upward protruding, semi-conical shape to allow easy removal of the nail. The smallest diameter portion of the semi-conical protrusion is located above the flat metal surface of the bottom portion of the shoe. This holds the head of the nail up and above the flat surface of the metal portion of the shoe, thereby enabling the claw of a hammer to grasp under the head of the nail to pull the nail more easily. A standard concrete form nail, with a double head, is another possible solution if a hole without the semi-conical shape is used in the shoe. The rubber tread 31 located under the bottom, metal surface of the leveler shoe, and riveted on, also has holes of a slightly smaller diameter, in line with the holes in the metal portion of the shoe, so that the nail can penetrate all the way though the shoe assembly, including the holes in rubber tread, and in between deck boards, or the nail can be pounded into a wood surface, such as a subfloor on a new building or on a sheathed roof (sloped or not) of a new structure. The nails can also be used to penetrate into a lawn or any other soft surface that may be wet, moldy, mossy and/or slippery. These holes can also be shaped as slots that would enable a shim or other sharp device to be slid through to act as a securing, or non-skid device. Claw Foot Locks in 90 Degree Rotation As shown in FIGS. 6 and 7 , the shoe has been modified to enable it to pivot 90 degrees in one direction, or 90 degrees in the opposite direction, totaling a potential pivoting action of 180 degrees, without the need to extend leg extension when leg extension is fully retracted in the “ready” position and to slide up and down when pivoted 90 degrees. This feature enables the shoe to function as a claw that works in conjunction with the automatic, back-up safety mechanism of the leveler with extendable leg or with any ladder leg having a square bottom end of the leg. The shoe has specially designed shapes and sizes, with carefully designed relationships between the shapes and sizes, including an elongated hole 205 through which a hinge pin couples the shoe to the ladder leg. When used together, these shapes and sizes and holes enable the bottom tread/claw surface and assembly of the shoe to pivot into the parallel position, in relation to the leg, and then, once pivoted into a parallel position, upward force applied to a claw end of the shoe will slide the shoe upward, the elongated hole allowing the hinge pin to move downward in the hole as shown in FIG. 7 , so that a lower corner of the square bottom of the ladder leg 206 contacts the shoe bottom structure to prevent the shoe from pivoting out of the parallel position. The contact surfaces which retrain the shoe in position are a bottom corner of the ladder leg 206 contacting the inside of the horizontal base plate of the shoe and a portion of the inner circumference of the elongated hole 205 contacting the hinge pin (which is bolt 33 in the preferred embodiment). The hole 205 is elongated in a direction parallel to the shoe base and may also be triangular as shown in FIGS. 6 and 7 . In effect, the shoe becomes wrapped around the lower, outer leg, thus pointing the claw, on the desired end of the shoe, downward toward, and/or into the slippery surface on which the ladder is erected. These special shapes and dimensions allow the shoe to pivot and wrap around the bottom end of the lower leg, while working together with the automatic, back-up safety mechanism, and without any type of interference between the leveler leg, safety mechanism or shoe assembly. Both the shoe locking system and the release lever locking system will remain locked in their respective positions until weight is removed from the ladder leveler. These new features provide a ladder leveler with a shoe and an automatic, back-up safety lock, having metal claws on either one or both ends of shoe, with the ability to pivot 180 degrees, slide up and down the leveler leg assembly and remain locked parallel to the leveler leg, thereby enabling the claw to dig into ice, snow or other slippery surfaces without concern for accidentally tripping the shoe to the flat position while on the ladder and without concern for retracting the leg extension. There are various ways to achieve these results, including, but not limited to A.) specially designed, triangular shaped holes in two side flanges of leveler shoe as shown in FIGS. 6 and 7 ; B.) specially shaped and sized side flanges of the shoe; and C.) specially shaped and sized bottom support structure of the ladder shoe (attached to rubber tread). The shoe, with claw facing downward and penetrating or contacting a support surface, will not flatten out (down) when any weight or load is being applied to the ladder leveler, even if a load, sudden or otherwise, is applied from a direction that is different from the angle of the ladder leveler legs. The end result is that the claw shoe, automatic safety lock and primary ratchet lock all remain in the locked position as long as weight or load is applied to the ladder leveler leg or the ladder to which the leveler leg is attached, even if the load (sudden or gradual) is applied to the side, back, front or top of the ladder leveler or ladder to which the ladder leveler is attached. This invention provides much more versatility in the ladder leveler because it enables the ladder user to quickly and easily flip the leveler shoe all the way back or forward, allowing the inside, upper surface of the bottom portion of the shoe to slide up against the leg, thereby activating the automatic, back-up, safety mechanism up against the pawl (and its release lever), thereby keeping the pawl locked, without the need to extend the leg extension several inches beforehand. This option enables a ladder user, who prefers not to extend the leveler leg, to easily use the claw on either end of the shoe (double claw shoe—front and back) when setting up a ladder on flat, even surfaces, or uneven surfaces, with ladder levelers that have automatic, back-up safety mechanisms installed. Lever Controls Actuatable with a Person's Foot As shown in FIGS. 8 and 9 , the release lever 75 , which is the upper of the two levers, is modified in its length and its shape so that it protrudes at least ¼″, better ⅜″, preferably 9/16″, but not more than 1″, beyond the shoe-contactable boundary of the leveler, creating a preferred relationship between the outer surfaces of the leveler and outer portion of the release lever. Preferably, the tip of the lever 209 has a upward curve. This improvement enables the user to depress the lever with his or her foot, shoe or toe, more quickly, ergonomically and with less physical effort. The proximity and immediate relationship between the two parts (outer surface of the leveler and the release lever) is critically important in how the locking system will respond when touched with a foot, and also in relation to the automatic, back-up, safety mechanism, which is deactivated when weight (load) is removed from the leveler shoe. The increased length of the release lever adds significantly to the ease of operation by creating quick and easy access to the lever, even when a person with large feet (large shoes) is attempting to depress the lever to release the locking system and retract the leg extension. The slight upward bend 209 in the release lever, located approximately ¼″ from the outermost tip of the lever, creates an angled edge for shoes that may be slippery from being wet, muddy or smooth from wear that is much easier to snag with a foot or toe. Additionally, the top surface of the lever, including the upwardly curved tip 209 , has grooves in it for extra grip. The release lever is also shaped so that it will not protrude from the outside face of the ladder leveler to a point at which it would be considered overly obtrusive, thereby creating interference, when the leveler is not in use and/or the ladder and leveler combination is being carried or stored. As shown in FIGS. 8 and 9 , the foot pedal 101 , which is the lower of the two levers, is modified in its length and its shape to enable the ladder user to quickly and easily catch the foot pedal of a ladder leveler with the bottom of a shoe or side of a shoe when the foot pedal needs to be snapped downward to the “READY” position for quickly extending the inner ladder leveler leg, thereby creating a faster, safer leveling operation without the need to bend over to use a hand to snap the foot pedal down into the “READY” position. The proximity and immediate relationship between the two parts (leveler's outer surface and the foot pedal) is critically important in how the foot pedal/locking system will respond when touched with a foot or shoe, particularly in relation to the automatic, back-up, safety mechanism, which is deactivated when weight (load) is removed from the leveler shoe, and activated when weight is placed on the leveler shoe. The special shape is designed so that it is easier to snap up and snap down with a foot, while activating or deactivating the back-up, automatic safety mechanism. This special shape, combined with the extra length (at least ⅛″ beyond the shoe-contactable boundary of the leveler, better 5/16″, preferably 9/16″, and no more than 1″ beyond the shoe-contactable boundary the leveler) is a more ergonomic shape, is easier to reach, and is combined with grooves running perpendicular to the length of the foot pedal for added non-slip features. The foot pedal is also shaped so that it will not protrude from the outside face of the ladder leveler to a point at which it would be considered overly obtrusive, thereby creating interference, when the leveler is not in use and/or the ladder and leveler combination is being carried or stored.

Improvements to the leg extension of an adjustable ladder leveler and, more generally, improvements to ladder legs. A shoe with a claw that folds to be parallel to the ladder leg and then slides upward with respect to the leg thereby becoming locked into position so that it cannot move away from being parallel so long as weight is applied on the ladder. If the shoe is on an extension, as the shoe slides up, it engages a safety bar that prevents release of the extension.

This application is a divisional application of U.S. Ser. No. 12/064,715, filed Feb. 25, 2008, now pending. This application claims the benefit of priority to France Application No: 05/08.845, filed Aug. 26, 2005. FIELD OF THE INVENTION The invention relates to the field of distributor trays intended to supply chemical reactors functioning in gas and liquid co-current down-flow mode with gas and liquid. Such reactors are encountered in the refining field, more particularly in the selective hydrogenation of various oil cuts, and more generally in hydrotreatments which require high pressure hydrogen streams operating with heavy liquid feeds which may contain impurities constituted by plugging solid particles. In some cases, the liquid feed contains impurities which may be deposited on the catalytic bed itself and over time may reduce the interstitial volume of that catalytic bed. Plugging feeds which may be cited include mixtures of hydrocarbons containing 3 to 50 carbon atoms, preferably 5 to 30 carbon atoms, which may contain a non-negligible proportion of unsaturated or polyunsaturated acetylenic or dienic compounds or a combination of those various compounds, the total proportion of unsaturated compounds possibly being up to 90% by weight in the feed. A representative example of feeds which are of relevance to the present invention is pyrolysis gasoline, “pyrolysis” designating a thermal cracking process which is well known to the skilled person. A description of that type of process and the corresponding products can be found in the work entitled “Raffinage et Génie Chimique” [Refining and Chemical Engineering] by P Wuithier, Editions Technip, page 708. The present invention allows for limiting the deposition of plugging particles in the catalytic bed. It thus contributes to keeping the bed homogeneous as regards the void fraction and thus the flow quality, and it allows also for limiting the increase in pressure drop. When a blockage occurs in a catalytic bed, the pressure drop in the flow through the reactor is observed to rise very rapidly. The pressure drop may become such that the operator is obliged to shut down the reactor and replace all or part of the catalyst, which clearly considerably reduces the run times of the process. Blockage of part of the catalytic bed may be due to a number of mechanisms. Directly, the presence of particles in the feed stream may cause a blockage by deposition of said particles in the catalytic bed, this deposition effectively reducing the void fraction. Indirectly, the formation of a layer of products derived from chemical reactions, typically coke, but possibly other solid products derived from the impurities present in the feed, which products are deposited at the surface of the catalyst grains, may also contribute to reducing the void fraction of the bed. Further, the plugging particles may be deposited in the bed in a more or less random manner and result in heterogeneities in the distribution of the void fraction of that bed which result in the creation of preferred pathways. Such preferred pathways are major problems from the hydrodynamic viewpoint as they can substantially perturb the homogeneity of flow of the phases in the bed and may contribute to heterogeneities in the progress of the chemical reaction, as well as thermal considerations. EXAMINATION OF THE PRIOR ART U.S. Pat. No. 3,702,238 proposes a system of conduits provided with calibrated breakage disks which are intended to deflect part of the flow of reagents when the catalytic bed becomes plugged. The increase in pressure ruptures the breakage disk and allows the feed to flow through the conduits. The instantaneous effect of deflecting part of the flow through the conduits is a large reduction in the pressure drop. The inlet to the conduits is located upstream or downstream of a distributor tray, but no system is provided for deflecting the liquid flow and the gas flow in a controlled or independent manner. No re-distribution device is provided in this case to homogenize the flow at the outlet from the conduits. This device also suffers from the disadvantage of being sensitive to sudden pressure variations. U.S. Pat. No. 3,607,000 and FR-A-7513027 propose systems composed of filter baskets placed upstream or at the head of the catalytic bed to collect impurities transported by the flow of reagents. In this case, a non-negligible volume of the bed is occupied by said baskets which do not actually prevent fouling of the fractions of the bed located between the baskets. Further, for gas/liquid flow applications, the system cannot control a homogeneous distribution of the gas/liquid flow between the baskets and downstream of the baskets. In the article by T H Lindstrom et al in Hydrocarbon Processing, February 2003 (pages 49-51), a system of external filters is described, but that system does not overcome all types of blockage and the cost of that solution is very high. U.S. Pat. No. 4,313,908 or EP-A2-0 050 505 describe devices which can reduce the increase in the pressure drop in the catalytic bed by deflecting part of the flow through tubes. A series of tubes forming a short-circuit pass through the catalytic bed. The inlet to those tubes is located downstream of a distributor tray and the outlet from those tubes opens above the inlet to the catalytic bed at various levels, The system can thus independently deflect the gas and liquid flows provided that a liquid level is established upstream of the bed. The device described in the cited patents cannot control the ratio between the liquid flow and the gas flow deflected into the tubes composing said system. The gas will be deflected from start-up of the reactor and the liquid will only be deflected when a sufficient liquid level has been established above the bed because of fouling. Further, there is no fluid distribution effect at the outlet from the devices described in the two cited patents, necessitating the downstream provision of a distributor tray or an equivalent system. In the case of the present invention, the distribution function is incorporated into the filtration system to form a single device. The more recent patent application WO-A1-03/000401 describes a device using tubes forming a short-circuit coupled with chambers also forming a short-circuit and acting to capture any impurities contained in the feed. That device does not include an effective system for re-distribution of gas/liquid effluents at the outlet from said chambers when the system is used in gas/liquid flow mode. The tray of the invention in U.S. Pat. No. 3,958,952 is constituted by a series of filtration units each being constituted by alternating concentric chambers, one empty and the other occupied by “filtration bodies” which are not described in detail. In such a system, the filtration function is completely separate from the mixing and distribution function, while in the device of the present invention, there is genuine synergy between the filtration bed and the mixing chimneys, as will be explained below. In fact, the filtration bed directly integrated with the tray has a secondary function of stabilizing the gas/liquid interface located above the tray, and thus contributes to a uniform supply of liquid to the mixing and distribution chimneys which form an integral part of said tray. U.S. Pat. No. 4,229,418 describes a tray system comprising filtration elements, but the term “filtration” in the context of that patent means permeability with respect to the process fluids and impermeability with respect to the catalyst particles, while in the context of the present invention, the term “filtration” means the capacity to retain plugging particles contained in the feed. Finally, the device described in the present invention is remarkably compact, in contrast to that of the prior art, and thus means that more catalyst can be used in a given volume of reactor, thereby increasing its efficiency. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 represents a diagram of a filtering distributor tray of the invention, said tray being placed upstream of a catalytic bed supplied with a feed having a gas portion and a liquid portion. FIG. 2 shows curves of the change, as a function of time, in the quantity of deposited impurities (curve A), of the pressure drop through a catalytic bed without a filtration bed (curve B) and of the pressure drop through a catalytic bed with a tray of the invention, i.e. provided with a filtration bed. BRIEF DESCRIPTION OF THE INVENTION The device described in the present invention can trap plugging particles contained in the liquid flow constituting part of the feed for a reactor functioning in gas and liquid down-flow co-current mode by means of a specific distributor tray comprising a filtration medium. The present invention consists of a device which can simultaneously distribute the gas phase and the liquid phase supplying a fixed bed reactor functioning with a down-flowing co-current of said phases, while ensuring a filtration function for impurities contained in the liquid phase constituting a portion of the feed to be treated. More precisely, the device of the invention is a device for filtering and distributing a gas phase and a liquid phase constituting the supply to a reactor comprising at least one fixed catalyst bed, functioning in a gas and liquid down-flow co-current mode, the liquid phase generally being charged with plugging particles, said device comprising a tray located upstream of the catalytic bed, said tray being constituted by a substantially horizontal base plane which is linked to the walls of the reactor and to which substantially vertical chimneys are fixed which are open at their upper end to admit gas and at their lower end to evacuate the gas-liquid mixture for supplying the downstream catalytic bed, said chimneys being perforated over a certain fraction of their height by a continuous lateral slot or lateral orifices for the admission of liquid, said tray supporting a filtration bed surrounding the chimneys and said filtration bed being constituted by at least one layer of particles with a size which is less than or equal to the size of the particles of the catalytic bed. Said filtration bed, which forms part of the distributor tray, is generally composed of a plurality of layers of particles of different sizes. The particles composing the various layers of the filtration bed are generally inert and usually formed from silica or alumina, or any other ceramic substance. In certain cases however, it may be advantageous for at least one layer of the filtration bed to be composed of particles which are active in the sense of the chemical reaction which takes place on the catalytic bed located downstream of the filtering distributor tray. In this case, the active particles are preferably composed of an identical catalyst or one belonging to the same family as the catalyst in the catalytic bed. In a further variation of the device of the invention, the filtration bed is composed of a packing structured with a porosity in the range between 35% to 50% (0.35 to 0.50). To prevent blockage of the lateral orifices of the chimneys or the lateral slot, each chimney is generally separated from the filtration bed which surrounds it by means of a screen with a sufficiently fine mesh, i.e. a mesh size which is lower than that of the particles of the filtration bed. In this case, the distance separating the chimney from the filtration bed is generally in the range from 5 mm to 20 mm. The filtration and distribution device of the invention is thus a filtering distributor tray with a base plane supporting the chimneys and the filtration bed which is preferably provided with orifices, with an orifice density of more than 100 orifices per m 2 section of reactor. The filtration and distribution device of the present invention can significantly extend the service life of the catalyst. In general, periodic replacement of the filtration bed is carried out with a periodicity of at least 6 months. The filtration and distribution device of the invention is particularly advantageous for use in hydrotreatment reactors, selective hydrogenation reactors or in the conversion of residues or hydrocarbon cuts with an initial boiling point of more than 250° C. DETAILED DESCRIPTION OF THE INVENTION The device of the present invention is composed of a distributor tray comprising a substantially horizontal base plane which is integral with the walls of the reactor, on which are fixed a set of substantially vertical chimneys provided with an upper opening and a lower opening and perforated with lateral orifices distributed all along their vertical walls. The gas portion of the supply penetrates into the inside of the chimneys essentially via the upper opening, and the liquid portion of the supply penetrates into the inside of the chimneys essentially via the lateral orifices. The term “essentially” means that at least 50%, preferably at least 80% of the gas and liquid respectively penetrate into the inside of the chimneys via the upper opening and via the lateral orifices. The gas and liquid are mixed inside the chimneys and the resulting mixture leaves the chimneys via the lower opening. The lateral orifices may form a continuous slot extending over the major portion of the height of the chimneys. The remainder of the text will refer to lateral orifices, but this will encompass the case of a continuous slot. The distributor tray supports a filtration bed constituted by at least one granular solid acting as a filter, said solid granular bed surrounding each of the chimneys over a fraction of their height. The chimneys are generally higher than the level of the filtration bed by a height (H′) of at least 30 mm, preferably more than 35 mm, or even more than 40 mm. The filtration bed may comprise a plurality of layers of particles of any shape. The size of the particles constituting each layer of the filtration bed reduces from the top to the bottom of the filtration bed. The particles of the lower (or the lowest) layer has a mean size which is preferably smaller than the size of the particles of catalyst constituting the catalytic bed located downstream of the distributor tray. In general, the size of the particles in each layer varies between 1 and 30 mm, preferably between 1 and 20 mm. In a variation of the filtration and distribution device of the invention, the filtration bed is composed of at least two layers of solid particles, the size of the particles of a given layer being smaller than that of the particles of the immediately superior layer. In a particular variation of the device of the invention, the size of the particles of the upper layer of the filtration bed is in the range from 5 mm to 30 mm, and the size of the particles of the lower layer is in the range from 2 mm to 10 mm. Purely by illustration, and without constituting any limitation, a filtration bed of the device of the invention may be constituted by: an upper layer representing 25% of the total height of the filtration bed and composed of particles with a size which is greater (preferably by at least 10%) than that of the catalyst grains; an intermediate layer representing 25% of the total height of the filtration bed, and composed of particles with a size approximately equal to that of the catalyst grains; a lower layer representing 50% of the total height of the filtration bed and composed of particles with a size lower (preferably by at least 10%) than that of the catalyst grains. The particles forming the filtration bed may have any shape, for example spherical or cylindrical, with or without void in the interior. They are generally inert, but may possibly be catalytic. In the latter case, the active particles of the filtration bed are generally constituted by a catalyst from the same family as the catalyst used in the catalytic bed located downstream of the filtration bed. The filtration bed may also be constituted by packing elements offering a large capture surface for impurities while offering a high void fraction. Examples of such packing elements which may be cited are inert particles composed of titanium and alumina with a cylindrical 20 mm diameter shape, in which cylindrical channels are formed. Examples of active particles which may be cited are 10 mm diameter beads containing nickel-molybdenum or cobalt-molybdenum as well as alumina. An example of a composition of a filtration bed using a plurality of layers is given in the detailed example following the present description. For the majority of industrial reactors, the total height of the filtration bed is in general in the range from 200 to 1500 mm, preferably in the range from 300 to 600 mm. The lateral orifices extend over the major portion of the height of the chimneys, but the lowest of them is preferably located at a minimum height (h) with respect to the base plane of the tray, which is preferably 50 mm above the base plane of said tray, or even 60 mm above. The “base plane of the tray” is the plane which is linked to the walls of the reactor and supporting the filtration bed. The orifices are preferably stepped over the whole height of the chimney to the maximum height (h′) which is preferably 20 mm above the upper surface of the filtration bed, or even 15 mm above. The minimum and maximum stepped heights of the lateral orifices may also apply in the case in which a continuous slot is used. The internal diameter of the chimneys is generally in the range from 10 mm to 150 mm, and preferably in the range from 25 mm to 80 mm. In one preferred implementation of the invention, a separation zone surrounding each chimney avoids direct contact of the filter with the chimneys to prevent the lateral orifices or the lateral slot of the chimneys from being obscured by the solid particles or the packing elements constituting the filtration bed. In this case, the distance separating the chimney from the filtration bed is generally in the range from 5 mm to 20 mm. The filtration bed plugs slowly over time, starting with the lower layers, and an interface is effectively created between the lower plugged portion and the upper non-plugged portion. The liquid passes through the filtration bed over its upper non plugged portion and penetrates through the chimneys via the lateral orifices. The gas phase is primarily introduced into the inside of the chimneys via their upper opening. A greater or lesser portion of the gas is also introduced via the lateral orifices of the chimneys or via the lateral slot. The upper opening of the chimneys is generally located at a height H′ above the filtration bed and is generally protected by a cap or any equivalent form which is aimed for preventing the direct introduction of liquid via said upper opening of the chimneys. The liquid introduced via the lateral orifices or the lateral slot thus mix with the gas phase inside the chimney and the resulting mixture is evacuated from the chimneys via the lower opening then is distributed to the catalytic bed located downstream of the distributor tray. In the remainder of the text, we shall term the ensemble of the device constituted by the distributor tray, the chimneys, and the filtration bed supported by said distributor tray the “filtering distributor tray”. The device of the present invention is thus composed of a filtering distributor tray linked to the internal cylindrical wall of the reactor and located above the catalytic bed. When the reactor includes a plurality of distinct catalytic beds, each of these catalytic beds may be supplied with a filtering distributor tray of the invention. In this case, the gas phase and the liquid phase supplying a given filtering distributor tray are constituted by effluents from the catalytic bed located immediately above it, to which may optionally be added a fluid introduced between two catalytic beds which in the case of hydrogenation or hydrotreatment reactions is usually a cooling fluid. The filtering distributor tray may also be pierced through its horizontal base plane by holes of any shape so that the overall porosity due to these holes can produce a minimum height of liquid on the tray, termed the liquid trap. A filtering distributor tray without holes through its base plane will function, however, and is included within the scope of the invention. The filtering distributor tray also supports chimneys which act to mix the gas and liquid and to route the resulting mixture towards the catalytic bed located in the zone downstream of the tray. The density of these chimneys is in the range from 10 to 150 per m 2 section of catalytic bed, preferably in the range from 30 to 100 per m 2 section of catalytic bed. All of the chimneys are provided with lateral orifices located at different levels stepped all the way along the vertical wall of the chimneys or a continuous longitudinal slot, allowing the liquid phase to pass inside said chimneys regardless of the level of plugging in the filtration bed. The shape of these lateral orifices or of the lateral slot is studied to adjust it according to the variation in the liquid flow rate during the operational cycle, as will be explained below. In the case of a lateral slot, the shape of said slot may be rectangular or triangular with the point of the triangle directed upwards or downwards. Any shape of slot is possible as long as the conditions regarding the height of the slot are satisfied. It preferably should commence at a height (h′) of at least 50 mm above the base plane of the tray and preferably extend to a height (h) of at least 20 mm above the upper level of the filtration bed. The distribution function of the gas/liquid flow is maintained as plugging progresses since the whole set of the chimneys is always used and the liquid flow rate remains approximately identical between the chimneys, this latter being essentially conditioned by the liquid level established on the tray. Thus, the importance of establishing and maintaining a certain liquid level above the base plane of the filtration tray will be appreciated. Further, the existence of the filtration bed contributes to stabilizing this liquid level by accommodating fluctuations in the interface between the gas and the liquid. Thus, the liquid distribution remains under control throughout the service life of the filtration bed and the progressive use of the lateral orifices or the lateral slots distributed along the whole length of the chimneys allows the filtration bed to be used until it is completely saturated, without the pressure gradient increasing which would mean that the unit would have to be shut down. A detailed description of the device of the invention is presented with the aid of FIG. 1 which concerns an embodiment in which the filtering distributor tray is constituted by a base plane 11 supporting a granular filtration bed 2 comprising three layers in the case of FIG. 1 . It will be recalled that a larger number of layers is perfectly possible and still falls within the scope of the present invention. The filtering distributor tray is located in the upper portion of a reactor supplied with a gas (G) and liquid (L) in a down-flow co-current flow. The filtering distributor tray is located upstream of a catalytic bed 10 in which a catalytic reaction occurs which employs the gas (G) and liquid (L) phases introduced at the head of the reactor. The filtering distributor tray is constituted by a base plane 11 on which chimneys 3 provided with lateral openings 4 , are fixed. In the case of FIG. 1 , the lateral openings 4 are constituted by longitudinal slots which are rectangular in shape, but they may equally be constituted by a slot with a non rectangular shape, for example triangular, or by a series of orifices of any shape distributed at different levels over the entire height of the chimneys 3 . The density of the chimneys 3 is in the range from 10 to 150 per m 2 , preferably in the range from 30 to 100 per m 2 . The distribution of chimneys 3 over the base plane 11 is regular and may be in a square or triangular pattern. The shape of particles constituting the filtration bed 2 is defined so as to develop a large area facilitating the deposition of impurities while maintaining a sufficient pore volume to capture the maximum amount of impurities and increase the service life of the filter. At the start of the cycle, a liquid level is established above the base plane 11 and the liquid flow is distributed over the whole section of the reactor through the orifices 12 located on the base plane of the tray 11 . It will be recalled that a base plane without an orifice is also possible and is encompassed in the scope of the invention, but preferably the base plane is provided with orifices, and in this case the density of the orifices located on the base plane of the tray 11 is, generally, at least equal to 100 orifices per m 2 . As the filtration bed 2 becomes plugged, the liquid level above the tray 11 increases and a portion of the liquid starts to flow through the rectangular slot 4 of the chimneys 3 . As plugging proceeds, the liquid level above the base plane of the tray 11 rises. When the filtration bed is completely plugged, liquid flows through the lateral slot 4 into its portion located above the upper level of the filtration bed 2 . In all cases, gas flows through the chimneys 3 and is principally introduced via the upper openings 6 , optionally provided with caps 7 to prevent liquid from being introduced via said upper openings 6 . A circular screen 8 surrounds the chimneys 3 to leave a void volume between the chimneys 3 and the filtration bed 2 , so that the particles of the filtration bed 2 do not obstruct the lateral slot 4 located along the chimneys 3 . The mesh size of this screen 8 will thus be smaller than the minimum diameter of the particles of the filtration bed 2 of the distributor tray. EXAMPLE The following example derives from a simulation using a kinetic equation for the deposition of particles which corresponds to a linear deposition as a function of time. The reactor had a diameter of 1 meter and a total height of 5 meters including the distributor tray and the catalytic bed. The catalytic bed was composed of particles of a traditional catalyst to carry out selective hydrogenation. It was a catalyst containing Ni deposited on an alumina support. The particle size of the catalyst forming the catalyst bed located downstream of the distributor tray was 2 mm. The reactor was supplied with a liquid portion and a gas portion. The liquid was constituted by a pyrolysis gasoline with a boiling point range in the range from 50° C. to 280° C. with a mean boiling point of 120° C. under standard conditions. The gas phase was composed of 90 mole % hydrogen, the remainder being essentially methane. The filtering distributor tray had 7 chimneys with a diameter of 50 mm and a height of 650 mm, each chimney being provided with a rectangular longitudinal slot with dimensions of 400 mm (height of slot) by 5 mm (width of slot). The lower end of the slot began at h=50 mm above the base plane of the tray. The filtration bed was composed of 4 layers of the same thickness denoted 1, 2, 3, 4 from bottom to top. The particles were inert alumina particles sold by AXENS society. The size characteristics of the particles and the porosity of each layer are given in Table I below. TABLE I Properties of particles Particle type Diameter (mm) Initial porosity of layer 1 st filtration tray layer 1.0 0.39 2 nd filtration tray layer 1.5 0.41 3 rd filtration tray layer 2.0 0.41 4 th filtration tray layer 2.5 0.43 Catalyst bed 2.0 0.41 The properties of the gas and liquid under the operating conditions of the reactor are given in Table II below: TABLE II Properties of fluids Density of liquid (kg/m 3 ) 710 Density of gas (kg/m 3 ) 15 Dynamic viscosity of liquid (Pa · s) 0.00085 Dynamic viscosity of gas (Pa · s) 0.00002 Superficial velocity of liquid (m/s) 0.0062 Superficial velocity of gas (m/s) 0.1000 Surface tension (N/m) 0.01 FIG. 2 shows the change with time: of the quantity of impurities deposited on the filtration bed represented by curve (A). This curve was obtained using a kinetic deposition equation; the pressure drop measured through the catalytic bed in the absence of a filtration bed, represented by curve (B); the pressure drop measured through the catalytic bed in the presence of the filtration bed of the invention, represented by curve (C). Curve (B) and (C) are approximately parallel, shifted with respect to time. This time shift corresponds to gradual plugging of the filtration bed. The plugging period extends from time t 0 to time tf, which corresponds to saturation of the filtration bed marked by the flat part of the curve (A). At time tf, curve (A) reached its flattened portion and beyond time tf, impurities contained in the liquid feed were no longer retained by the filtration bed. with the tray without a filtration bed (prior art), the pressure drop through the catalytic bed increases sharply from time tb to a limiting value of the pressure drop which is allowable by the reactor; with the filtration tray with its filtration bed according to the present invention, the pressure drop through the catalytic bed increases sharply from time to which is clearly shifted with respect to time tb. This tc-tb shift quantified the improvement provided by the tray of the invention since during the whole supplemental period corresponding to tc-tb, the pressure drop through the catalytic bed is practically constant, and remains the same as its value at the start of the cycle, t 0 . The tray of the invention can thus extend the service life by a period equivalent to tc-tb. In the present case, said extension is 80% compared with the cycle time with a distributor tray without a filtration bed.

The device described in the present invention can trap plugging particles contained in the liquid feed supplying a reactor functioning in gas and liquid co-current down-flow mode using a specific distributor tray comprising a filtration medium. The present device is of particular application to the selective hydrogenation of feeds containing acetylenic and dienic compounds.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/983,213, filed on Apr. 23, 2014, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] This invention relates to aspiration needle devices and uses therefore, particularly their applications in the biopsy procedures to obtain biological samples. BACKGROUND OF THE INVENTION [0003] Biopsy devices for fine needle aspiration (FNA) are widely used for screening diagnostic procedures and are useful for obtaining cytological specimens for examination, for example, to confirm the diagnosis of a suspected medical condition. Typical specimens collected include liquids or cell samples. Such devices are generally useful in sampling tissue from breast, head and neck, lymph nodes, and for some gynecologic conditions. Other applications include lung, prostate, and other soft tissue biopsies. [0004] Generally, biopsy devices of this type extract samples of tissue through a small needle in the range of 25-18 gauge. The needle is inserted, typically through the skin, so that the tip of the needle is in the suspect tissue mass. A vacuum force is applied by withdrawing the plunger of a standard syringe attached to the needle. To aid in harvesting an adequate sample size, the needle is optionally moved in and out of the puncture site a plurality of times. This reciprocating motion causes cellular material to be scraped from the tissue and drawn into the needle. This procedure draws up a small amount of tissue fluid, together with loose cells, into the syringe, and the collected specimen can be directly placed on a slide for pathological analysis. [0005] Most existing FNA biopsy procedures use the regular needle-syringe systems, which are designed for the purpose of injection instead of aspiration biopsy, and therefore, have many limitations. After the procedure is done with a regular needle-syringe system, the specimen usually spreads all over the needle, needle-syringe joint, and/or inside of the syringe. Only a small fraction of the collected specimen could be directly placed on a slide usable for pathological analyses, and a major portion of the specimen is left in the needle and syringe. For additional analysis, the specimen has to be transferred into different containers through an extra procedure such as washing, which would cause substantial loss of the precious specimen as well as possible damages to the fresh specimen. Often, with the existing FNA needles, the procedure has to be repeated multiple times in order to obtain enough samples for the required analyses. [0006] On the other hand, multiple biomarker identifications have become more and more important in the modern personalized medicines, especially in cancer diagnosis and treatment. Effective uses of a small quantity of biopsy specimen for multiple tests are highly desirable and often required. Therefore, aspiration and biopsy devices and methods capable of collecting maximally usable biological samples are in great need. SUMMARY OF THE INVENTION [0007] The present invention provides new aspiration/biopsy needle devices to meet the foregoing need, which can overcome the various shortcomings of the conventional sample collection methods mentioned above. [0008] The fine needle aspiration biopsy devices described here are novel useful tools for the FNA biopsy procedures, which can be readily used to minimize the loss of and/or damages to the specimen collected, yet are suitable for use in the normal operations of the conventional procedures. [0009] In one aspect the present invention provides an aspiration or biopsy device comprising: a body, a cannula needle, and a sample collection container, wherein: [0010] the body comprises a vacuum channel and a plurality of ports; [0011] the cannula needle comprises an inlet end positioned at a first port of the body, an outlet end positioned at a second port of the body, and a middle portion enclosed inside the body; and [0012] the vacuum channel of the body comprises a first opening end positioned at the second port of the body and a second opening end positioned at a third port of the body in communication with a vacuum source; and [0013] the sample collection container is coupled with the second port of the body, enclosing both of the outlet end of the cannula needle and the first opening end of the vacuum channel; [0014] wherein the inlet end of the cannula needle is capable of aspirating a sample from a target when vacuum is applied on the second opening of the vacuum channel. [0015] In another aspect the present invention provides a needle apparatus comprising a body and a cannula needle, wherein: [0016] the body comprises a vacuum channel and a plurality of ports; [0017] the cannula needle comprises an inlet end positioned at a first port of the body, an outlet end positioned at a second port of the body, and a middle portion enclosed inside the body; and [0018] the vacuum channel of the body comprises a first opening end and a second opening end, wherein the first opening end is positioned at the second port of the body so that the first opening end of the vacuum channel and the outlet end of the cannula needle can be contained in a same sample collection container coupled to the second port of the body, and the second opening end is positioned at a third port of the body, which can be in communication with a vacuum source. [0019] In another aspect the present invention provides an aspiration device comprising a needle apparatus according to any one of the embodiments disclosed herein. [0020] In another aspect the present invention provides a biopsy device comprising a needle apparatus according to any one of the embodiments disclosed herein. [0021] In another aspect the present invention provides a method of extracting a biological sample from a subject, comprising: (1) providing a needle apparatus, an aspiration device, or a biopsy device according to any embodiment disclosed herein; (2) contacting the inlet end of the cannula needle of the device with a target of a desired biological sample; (3) applying a vacuum on the vacuum channel so that a desired biological sample is transferred through the cannula needle to a sample collection container. [0022] In another aspect the present invention provides an aspiration method comprising: [0023] a) providing an aspiration or biopsy device of any embodiment disclosed herein, or attaching a needle apparatus according to any embodiment disclosed herein to a sample collection container and a vacuum source; and b) aspirating a specimen through the needle inlet from a sample target into the sample collection container by applying a vacuum on the vacuum channel of the needle apparatus. [0024] In one particular embodiment, the invention provides a fine needle aspiration (FNA) biopsy device for improved cell harvesting and a method of using the device. In one embodiment, the integrated fine needle aspiration (FNA) device comprises a detachable vial. In another embodiment, the integrated fine needle aspiration (FNA) device comprises a needle for penetration; an attached vial for receiving the specimen; and a syringe hub connector for attaching a vacuum source. In one embodiment, the syringe hub connector is a standard one. In another embodiment, the syringe hub connector is one having a specific size or shape to meet the need. In one embodiment, the vacuum source is a syringe, which can be a standard commercial one or a specifically designed one. In another embodiment, the vacuum source is a vacuum line optionally controlled by a vacuum gauge. [0025] Among many other advantages, the aspiration needle system and the aspiration or biopsy devices of the present invention are easy to manufacture; convenient to assemble, dissemble, handle, and use, with each part easy to sterilize; and readily adaptable to different uses. All the parts of the apparatus or devices disclosed herein can be manufactured to fit the commercially readily available syringes, sample vials, needles, etc. manufactured according to the existing industrial standards. More importantly, the aspiration or biopsy methods using the system or devices of the present invention enable efficient extraction and use of biological samples while minimizing loss and damages to the specimens and preserving integrity of the specimens. The aspiration/biopsy devices capable of collecting maximally usable specimens will greatly benefit the clinical practices and the patients. Such devices are especially useful for extracting biological samples for early diagnosis of diseases, such as tumors, because the availability of samples is limited, and extraction of samples is difficult, at the early stage of the diseases. [0026] These and other aspects of the present invention and advantages will become more apparent in view of the following drawings, detailed descriptions, and claims. BRIEF DESCRIPTION OF THE DRAWINGS [0027] FIG. 1 illustrates a fine needle aspiration device of the present invention that can be connected with a syringe. [0028] FIG. 2 illustrates a fine needle aspiration device that can be connected with a vacuum line. [0029] FIG. 3 illustrates a main center piece of the fine needle aspiration device. [0030] FIG. 4 illustrates a fine needle aspiration device without attachments. [0031] FIG. 5 illustrates an example of receiving vial for the fine needle aspiration device. [0032] FIG. 6 illustrates the fine needle aspiration devices in various example shapes. [0033] FIG. 7 illustrates various example dimensions of the fine needle aspiration devices. [0034] FIG. 8 illustrates example dimensions of receiving vials for the fine needle aspiration devices. [0035] FIG. 9 illustrates an example of the fine needle aspiration device with a detachable penetration needle. [0036] FIG. 10 illustrates an example of the fine needle aspiration device connected with a detachable penetration needle. [0037] FIG. 11 illustrates example dimensions of a detachable needle suitable for the fine needle aspiration devices. DETAILED DESCRIPTION OF THE INVENTION [0038] This invention, in one aspect, relates to fine needle aspiration (FNA) biopsy devices for improved cell harvesting and methods of using the devices, including but not limited to integrated fine needle aspiration (FNA) devices with detachable vials. For example, an integrated fine needle aspiration (FNA) device comprises a needle for penetration; an attached vial for receiving the specimen; and a standard syringe hub connector for attaching the vacuum source, such as a syringe. During the FNA biopsy procedure, the needle is inserted into a suspect tissue, a vacuum is created by a syringe or other vacuum sources, and cells and tissue from the targeted tissue mass are sucked through the needle into the attached vial. After the sample is obtained, the vial with the specimen sample can be detached from the device, and the sample is ready for examination. [0039] Thus, in one aspect the present invention provides an aspiration or biopsy device comprising: a body, a cannula needle, and a sample collection container, wherein: [0040] the body comprises a vacuum channel and a plurality of ports; [0041] the cannula needle comprises an inlet end positioned at a first port of the body, an outlet end positioned at a second port of the body, and a middle portion enclosed inside the body; and [0042] the vacuum channel of the body comprises a first opening end positioned at the second port of the body and a second opening end positioned at a third port of the body in communication with a vacuum source; and [0043] the sample collection container is coupled with the second port of the body, enclosing both of the outlet end of the cannula needle and the first opening end of the vacuum channel; [0044] wherein the inlet end of the cannula needle is capable of aspirating a sample from a target when vacuum is applied on the second opening of the vacuum channel. [0045] In one embodiment of this aspect, the middle portion of the cannula needle is in airtight or substantially airtight contact with internal walls of the body surrounding the cannula needle. [0046] In another embodiment of this aspect, the inlet and outlet ends of the cannula needle are two distinct pieces connected with each other through a connection means at the first port of the body. [0047] In another embodiment of this aspect, the inlet end of the cannula needle comprises a detachable needle. [0048] In another embodiment of this aspect, the inlet end piece comprises a needle of a commercially standard size and/or dimensions. [0049] In another embodiment of this aspect, the inlet end of the cannula needle comprises a tip having a shape and dimension suitable for aspiration of a biological sample from an internal organ of a mammalian animal. [0050] In another embodiment of this aspect, the second port of the body comprises a connection means to couple the body and the sample collection container. [0051] In another embodiment of this aspect, the connection means is airtight or substantially airtight so that when a vacuum is applied on the vacuum channel, a sample can be aspirated by the inlet end of the cannula needle to the sample collection container. [0052] In another embodiment of this aspect, the connection means fits a commercial sample collection container of standard size and/or dimensions. [0053] In another embodiment of this aspect, the connection means is a clip mechanism, a screw mechanism, or a combination thereof. [0054] In another embodiment of this aspect, the sample collection container is a disposable commercial sample vial. [0055] In another embodiment of this aspect, the sample collection container is a centrifugation tube. [0056] In another embodiment of this aspect, the inlet end of the cannula needle is protected by a cover. [0057] In another embodiment of this aspect, the protection cover of the inlet end of the cannula needle comprises a plastic sheath. [0058] In another embodiment of this aspect, the vacuum source comprises a means for generating a vacuum. [0059] In another embodiment of this aspect, the means for generating a vacuum is selected from a vacuum pump, a syringe, an adaptor to connect with a vacuum line, or a combination thereof. [0060] In another embodiment of this aspect, the vacuum source comprises a syringe. [0061] In another embodiment of this aspect, the syringe is connected with the third port of the body through a connecting means so that the syringe can directly apply vacuum on the second opening end of the vacuum channel. [0062] In another embodiment of this aspect, the connecting means is airtight or substantially airtight. [0063] In another embodiment of this aspect, the connecting means is selected from clip mechanisms, screw mechanisms, and combinations thereof. In a preferred embodiment, the connection means is a standard syringe hub connector. [0064] In another embodiment of this aspect, the connecting means is a standard screw that fits with a commercial syringe of standard size and dimensions. [0065] In another embodiment of this aspect, the syringe is a disposable one. [0066] In another embodiment of this aspect, the vacuum channel further comprises a vacuum duct enclosed inside and attached to the internal wall of the channel. [0067] In another embodiment of this aspect, the vacuum duct comprises two opening ends extending outside the channel, wherein one opening end extends to the sample collection container, and the other opening end is in communication with a vacuum source. [0068] In another embodiment of this aspect, the vacuum duct is a cannula needle, a metal tubing, or a plastic tubing. [0069] In another embodiment of this aspect, the opening end of the vacuum duct in the sample collection container is at a distance from the opening of the outlet end of the cannula needle so that they are not in proximity with each other to prevent the sample collected from entering the vacuum duct. [0070] In another embodiment of this aspect, the portion of the vacuum duct in the sample collection container is shorter than the outlet end of the cannula needle in the sample collection container. [0071] In another embodiment of this aspect, the vacuum duct comprises a cannula needle having a sharp tip at the opening end in the sample collection container so that it can penetrate a rubber cap or stopper of a sample collection container. [0072] In another embodiment of this aspect, at least one or two of the sample inlet needle piece, the sample collection container, and the vacuum source are provided separately in sterilized containers, respectively, from the body, and the device can be assembled right before use. [0073] In another embodiment of this aspect, the device is pre-assembled and stored in a sterilized container ready for use. [0074] In another embodiment of this aspect, all the parts of the aspiration device are disposable after a single use. [0075] In another embodiment of this aspect, the aspiration device is a fine needle aspiration (FNA) device. [0076] In another aspect the present invention provides a needle apparatus comprising a body and a cannula needle, wherein: [0077] the body comprises a vacuum channel and a plurality of ports; [0078] the cannula needle comprises an inlet end positioned at a first port of the body, an outlet end positioned at a second port of the body, and a middle portion enclosed inside the body; and [0079] the vacuum channel of the body comprises a first opening end and a second opening end, wherein the first opening end is positioned at the second port of the body so that the first opening end of the vacuum channel and the outlet end of the cannula needle can be contained in a same sample collection container coupled to the second port of the body, and the second opening end is positioned at a third port of the body, which can be in communication with a vacuum source. [0080] In one embodiment of this aspect, the middle portion of the cannula needle is in airtight or substantially airtight contact with internal wall of the body surrounding the cannula needle so that the inlet end of the cannula needle can extract a sample from a target when a sample collection container is coupled to the second port of the body, enclosing both of the outlet end of the cannula needle and the first opening end of the vacuum channel, and a vacuum is applied on the second opening end of the vacuum channel at the third port. [0081] In another embodiment of this aspect, the vacuum channel further comprises a vacuum duct enclosed inside and attached to the internal wall of the channel. [0082] In another embodiment of this aspect, the vacuum duct comprises two opening ends extending outside the channel, wherein one opening end extends to the sample collection container, and the other opening end is in communication with a vacuum source. [0083] In another embodiment of this aspect, the vacuum duct is a cannula needle, a metal tubing, or a plastic tubing. [0084] In another embodiment of this aspect, the opening end of the vacuum duct in the sample collection container is at a distance from the opening of the outlet end of the cannula needle so that they are not in proximity with each other to prevent the sample collected from entering the vacuum duct. [0085] In another embodiment of this aspect, the portion of the vacuum duct in the sample collection container is shorter than the outlet end of the cannula needle in the sample collection container. [0086] In another embodiment of this aspect, the vacuum duct comprises a cannula needle having a sharp tip at the opening end in the sample collection container so that it can penetrate a rubber cap or stopper of a sample collection container. [0087] In another embodiment of this aspect, the inlet and outlet ends of the cannula needle comprise two distinct pieces connected with each other through a connecting means between the inlet end needle and the first port of the body. [0088] In another embodiment of this aspect, the inlet end piece of the cannula needle is a replaceable needle. [0089] In another embodiment of this aspect, the inlet end piece is a commercial needle of standard size and dimensions for aspiration of biological samples. [0090] In another embodiment of this aspect, the inlet end of the cannula needle comprises a sampling tip of a size and shape suitable for aspiration of a biological sample from a mammalian subject. [0091] In another embodiment of this aspect, the second port of the body comprises a connection means to couple with a sample collection container. [0092] In another embodiment of this aspect, the connection means is airtight or substantially airtight so that when a vacuum is applied on the vacuum channel, a biological sample can be aspirated by the inlet end of the cannula needle. [0093] In another embodiment of this aspect, the connection means fits a standard commercial sample vial. [0094] In another embodiment of this aspect, the airtight connection means comprises a clip mechanism, a screw mechanism, or a combination thereof. [0095] In another embodiment of this aspect, the sample collection container is a disposable commercial sample vial. [0096] In another embodiment of this aspect, the sample collection container is a centrifugation tube. [0097] In another embodiment of this aspect, the apparatus further comprises a cover to protect the inlet end of the cannula needle. [0098] In another embodiment of this aspect, the protection cover at the inlet end of the cannula needle is a plastic sheath. [0099] In another embodiment of this aspect, the vacuum source is selected from a vacuum pump, a syringe, and an adapter connected with a vacuum line, or a combination thereof. [0100] In another aspect the present invention provides an aspiration/biopsy device comprising a needle apparatus according to any one of the embodiments disclosed herein. [0101] In one embodiment of this aspect, the aspiration device further comprises a sample collection container, wherein said sample collection container is coupled to the second port of the body of the needle apparatus and encloses the outlet end of the cannula needle and the first opening end of the vacuum channel. [0102] In another embodiment of this aspect, the aspiration device further comprises a vacuum source connected to the second opening end of the vacuum channel. [0103] In another embodiment of this aspect, the vacuum source is a syringe. [0104] In another embodiment of this aspect, the syringe is connected to the third port of the body through a connecting means. [0105] In another embodiment of this aspect, the connecting means is a clip mechanism, a screw mechanism, or a combination thereof. In a preferred embodiment, the connection means is a standard syringe hub connector. [0106] In another aspect the present invention provides an aspiration/biopsy device comprising a needle apparatus according to any one of the embodiments disclosed herein. [0107] In one embodiment of this aspect, the biopsy device further comprises a sample collection container, wherein said sample collection container is coupled to the second port of the body of the needle apparatus and encloses the outlet end of the cannula needle and the first opening end of the vacuum channel. [0108] In another embodiment of this aspect, the biopsy device further comprises a vacuum source connected to the second opening end of the vacuum channel. [0109] In another embodiment of this aspect, the vacuum source is a syringe. [0110] In another embodiment of this aspect, the syringe is connected to the third port of the body through a connecting means. [0111] In another embodiment of this aspect, the connecting means is a clip mechanism, a screw mechanism, or a combination thereof. In a preferred embodiment, the connection means is a standard syringe hub connector. [0112] In another aspect the present invention provides a method of extracting a biological sample from a subject, comprising: (1) providing a needle apparatus, an aspiration device, or a biopsy device according to any embodiment disclosed herein; (2) contacting the inlet end of the cannula needle of the device with a target of a desired biological sample; (3) applying a vacuum on the vacuum channel so that a desired biological sample is transferred through the cannula needle to a sample collection container. [0113] In one embodiment of this aspect, the method further comprises (4) rinsing the cannula needle with a liquid to transfer the residue of the sample from the cannula needle to the sample collection container. [0114] In another embodiment of this aspect, the sample collection container is a glass or plastic vial or a glass or plastic centrifugation tube. [0115] In another embodiment of this aspect, the target of the biological sample is an organ of a subject or another biological sample. [0116] In another embodiment of this aspect, the biological sample is a block of cells, a solid tissue, or a fluid. [0117] In another embodiment of this aspect, the solid tissue is a tumor tissue. [0118] In another embodiment of this aspect, the sample target is an internal organ or a mammalian animal, such as a human, a dog, a cat, a horse, or the like. [0119] In another aspect the present invention provides an aspiration method comprising: [0120] a) providing an aspiration or biopsy device of any embodiment disclosed herein, or attaching a needle apparatus according to any embodiment disclosed herein to a sample collection container and a vacuum source; and b) aspirating a specimen through the needle inlet from a sample target into the sample collection container by applying a vacuum on the vacuum channel of the needle apparatus. [0121] In one embodiment of this aspect, the step b) further comprises rinsing residue of the biological sample from the cannula needle into the sample collection container by contacting the inlet end of the cannula needle with a rinsing liquid and applying a vacuum on the vacuum channel of the needle apparatus in a controlled amount. [0122] In another embodiment of this aspect, the method further comprises c) detaching the sample collection container from the body of the aspiration or biopsy device or the needle apparatus. [0123] In another embodiment of this aspect, the sample collection container is an analytical sample vial ready for analysis. [0124] In another embodiment of this aspect, the sample collection container is a centrifugation tube, and the method further comprises d) concentrating the sample solution by centrifugation. [0125] The needle apparatus and devices thereof according to the present invention are versatile and adaptable for different uses, for example, aspiration of fluid samples and biopsy of soft tissues, by varying design of the needle. For example, fluid biological samples can be readily extracted using regular disposable needle; and using a needle having a tip suitable for scraping soft tissues or even bone samples, the devices can be used for biopsy of those solid samples. The flexibility makes the devices especially useful for bone marrow aspiration or biopsy procedures as well as biopsy of various solid tumors, such as breast, head and neck, prostate, lung, stomach, liver, and brain cancers, and melanomas, etc. [0126] The dimensions and specifications of the devices and apparatus disclosed herein can be adjusted to suit any particular use for extraction of biological samples, as a person skilled in the art will be able to do based on the disclosure and known practice in the medical field. For example, thickness, internal diameter, and lengths of the middle portion and the inlet and outlet ends of the needles can be adjusted based on the need and procedures in which the device or apparatus is used, as well as conditions under which the procedure takes place, which may include, but are not limited to, the source of the biological sample to be extracted, the nature and property of the biological sample to be extracted, and the amount to be extracted, etc. [0127] In the present invention, the same device or apparatus may be suitable for use in both aspiration of liquid samples and biopsy of soft tissue or solid tissue samples by altering dimensions and/or shape of the specifications, for example, in particular, the tip of the inlet end of the cannula needle, as would be grasped by those skilled in the art. In this aspect, the detachable needle in the inlet end is particular desirable so that it can be changed readily, sterilized, and reused. [0128] In some embodiments, the terms “aspiration” and “biopsy” may be interchangeable for the purpose of the present invention, and thus they may be collectively called “extraction” of a biological sample. The term “target” or “source”, or the like, of a biological sample in a “subject”, as used herein refers to an organ, tissue, blood, or any body part of a mammalian animal, preferably a human. [0129] Although it would be preferable to have all or most of the connection means mentioned in the application meet the existing industrial standards so that they would be convenient to use and can avoid unnecessary special manufacturing costs, nevertheless, in principle, they can be manufactured customarily for different purposes without any specific limitations. EXAMPLES [0130] The following non-limiting examples of certain embodiments are provided to further illustrate certain aspects of the present invention. [0131] Some needle aspiration devices for obtaining tissue samples are illustrated in FIG. 1 and FIG. 2 . These devices may be used in substantially all procedures employing conventional FNA devices and further increase the efficiency of FNA procedures with minimum loss of the collected specimen. [0132] As illustrated in FIG. 3 , the invention of the integrated fine needle aspiration (FNA) device comprises a cannula penetration needle 101 with one sharp end for the penetration of the targeted tissue, and the other end inside the attached receiving vial 104 . During the procedure, the sharp tip of the penetration needle 101 penetrates into the target tissue mass and extracts a small amount of the tissue and cells by utilizing an in-and-out motion. The tissue fluid, together with loose tiny pieces of tissues and cells, is drawn directly into the attached receiving vial 104 through the cannula penetration needle 101 . [0133] As illustrated in FIG. 3 , the invention of the integrated fine needle aspiration (FNA) device comprises also a vial holder with 108 , such as a click lock, through which, a receiving vial 104 is attached. The receiving vial 104 can be the common centrifuge vials with cap 110 that has a hole and a penetrable PTFE/silicone seal septum 109 as illustrated in FIG. 4 . The vial holder 108 has two needle outlets. The first needle outlet is the other end of the cannula of the penetration needle 101 , through which the specimen is guided into the receiving vial 104 . The second needle outlet is the end of the cannula of the vacuum needle 107 . Or in other embodiments, the second needle outlet is connected to a vacuum line through a tubing, duct, or the like. During the procedure, vacuum is generated inside the receiving vial 104 through the vacuum needle 107 by either a syringe 111 as illustrated in FIG. 1 , or by other vacuum sources such as vacuum line 112 as illustrated in FIG. 2 . The vial holder 108 has also a build-in click lock, which holds the receiving vial 104 in place during the procedure. The receiving vial 104 can be easily detached from the vial holder 108 with release of the click lock after the procedure. The specimen in the receiving vial 104 can be directly used for analysis. If desired, the specimen trapped inside the cannula of the penetration needle 101 can be washed into the receiving vial 104 by drawing a small quantity of proper washing buffer solution through the penetration needle 101 before detaching the receiving vial 104 . [0134] As illustrated in FIG. 3 , the invention of the integrated fine needle aspiration (FNA) device comprises also a syringe connector 103 , which can be of a standard or non-standard size. For economic and convenience reasons, in some preferred embodiments, the syringe connector is of standard sizes so as to fit different standard sizes of syringes. A common standard syringe 111 can connected to the universal connector 103 as illustrated in FIG. 1 , and the biopsy procedure can be performed in the same way as the conventional FNA biopsy. Furthermore, through this universal standard syringe connector 103 , various vacuum sources, such as a standard syringe-needle connector 106 with a tube linked to the in-house vacuum port, can be connected to the FNA device of the current invention as illustrated in FIG. 2 . The biopsy procedure can be performed easily by directly handling the device without withdrawing the plunger of the syringe. [0135] During the FNA biopsy procedure, the needle is inserted into the suspect tissue, a vacuum is created by the syringe or other vacuum sources, and cells and tissue from the targeted mass are sucked through the needle into the attached vial. When the sample is obtained, the vial with the specimen sample is detached from the device and ready for examination. [0136] As illustrated in FIG. 6 , the receiving vial can be orientated to different angles to fit different biopsy positions for easy handling and preventing the sample from being sucked into the vacuum needle. [0137] As illustrated in FIG. 7 , the penetration needle 101 can vary in size from 30-16 gauge, and 1 to 12 inch long to meet different needs for the different type of the target tissue and organs. The main body 113 of the device can also vary in size, such as from 1 inch to 3 inches. The smaller size, such as 1 inch, is for the device that is connected to a syringe as illustrated in FIG. 1 . The larger size, such as 3 inches, is for the device that is connected to a vacuum line as illustrated FIG. 2 for easy manual handling. The size of the vial holder 108 can be ¼ to 1 inches in diameter and ¼ to ¾ inches in depth to fit the most commonly used receiving vials 104 . The size of the receiving vial 104 can range from 0.5 ml to 5 ml depend on the sample types and sizes. Small sized receiving vial is for the biopsy of small quantity of solid tissue samples, while the larger receiving vial is for the fluid samples, which is frequently in relative larger volume. [0138] As illustrated in FIG. 9 , the invention of the integrated fine needle aspiration (FNA) device can be modified to comprise also a detachable penetration needle 115 . The detachable penetration needle 115 has a flat head connector, which can be tightly connected to the flat bottom needle connector of the main FNA body 114 . The connectors were designed with tightly matched flat head/bottom connection to eliminate the dead space inside the connectors as illustrated in FIG. 10 . [0139] As illustrated in FIG. 11 , the detachable penetration needle 115 can vary in size from 30-16 gauge, and 1 to 12 inch long to meet different needs for the different type of the target tissue and organs. [0140] The foregoing examples and description of certain embodiments should be taken as illustrating, rather than as limiting the present invention as defined by the claims. As will be readily appreciated, numerous variations and combinations of the features set forth above can be utilized without departing from the present invention as set forth in the claims. All such variations are intended to be included within the scope of the following claims.

This application discloses aspiration/biopsy needle apparatus, devices containing these needle apparatus, and methods using these needle apparatus and devices for aspiration or biopsy of samples, in particular biological samples from mammalian subjects. The novel aspiration/biopsy needle systems can find wide applications in the manufacture of fine needle aspiration (FNA)/biopsy devices for convenient cell harvesting and tissue sampling and analysis.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Divisional Application of U.S. Ser. No. 12/356,163 filed Jan. 20, 2009, which is a Continuation application of U.S. Ser. No. 11/940,375 filed Nov. 15, 2007 (abandoned), herein incorporated by reference in their entirety. FIELD OF THE INVENTION The present invention relates to the field of agronomy, more particularly to agricultural fertilizing compounds. BACKGROUND OF THE INVENTION Higher plants are autotrophic organisms that can synthesize all of their molecular components from inorganic nutrients obtained from the local environment. Nitrogen is a key element in many compounds present in plant cells. It is found in the nucleoside phosphates and amino acids that form the building blocks of nucleic acids and proteins, respectively. Availability of nitrogen for crop plants is an important limiting factor in agricultural production, and the importance of nitrogen is demonstrated by the fact that only oxygen, carbon, and hydrogen are more abundant in higher plant cells. Nitrogen present in the form of ammonia or nitrate is readily absorbed and assimilated by higher plants. Because of the dependence of plants upon nitrogen, farmers frequently include nitrogen in their fertilization efforts of their fields in an effort to increase yield. This practice may be traced back to the 1800's, when it was discovered that when external sources of water soluble forms of nitrogen (along with phosphorus and potassium) provided to plants, yield increased. These fertilizers are typically applied to the soil, but can also be applied to plant leaves directly. Nitrogen fertilizers are often synthesized using the Haber-Bosch process, which results in the production of ammonia. The ammonia is then either applied to the soil or used to produce other nitrogen compounds, such as ammonium nitrate or urea. These compounds are then applied to crop fields in order to increase yield in areas where the nitrogen content of the soil is low. Unfortunately, the production and use of nitrogen fertilizers has significant drawbacks. For example, it is currently estimated that ammonia production accounts for 5% of the global consumption of natural gas. With the increase of natural gas prices over the course of the past decade, the cost of producing ammonia has correspondingly increased. In addition, overuse of nitrogen fertilizer can lead to pest problems by increasing the birth rate, longevity, and overall fitness of certain crop pests. Also, there are substantial concerns regarding fertilizer runoff, which can add undesirable compounds to rivers, streams, and ground water supplies. It would therefore be desirable to minimize the application of inorganic fertilizers to field crops while finding a way that the increased yield those fertilizers typically provide may still be obtained. Another source of plant nutrition historically has been humus, which is commonly referred to as organic matter. Humus is sometimes referred to simply mean mature compost, and is often thought to make up the structural component of soil. Most humic compounds are produced via the composting process, but others are available from other sources, such as peat moss, manure, and coal. Such humic compounds have been used as soil enhancers or fertilizers for quite some time, but the greater benefit seen by artificial application of inorganic compounds such as nitrogen described above have proven more beneficial in most farming applications, or at least more cost effective. Because of this perceived greater benefit to the application of inorganic nitrogen and other compounds (such as potassium and phosphorus), the level of humic compounds present in the soil has progressively declined with the increase in commercial farming and the lack of replenishment. As a result, greater amounts of inorganic fertilizers are needed in order to achieve the same or similar fertilizing effect, as the soil in many instances is less able to retain the chemical fertilizers applied to it, and as a result plants are less able to utilize such fertilizers unless they are applied in greater quantities. This shift in soil dynamics over the course of time has contributed to the negative impacts of chemical fertilizers noted above, as with increased application of such fertilizers, there is a corresponding increase in the potential for occurrence of the negative side effects of such fertilizers. While these problems have been recently identified, a suitable solution has yet to be found. Combining various humic substances with various inorganic fertilizing materials, such as nitrogen, phosphorus, and potassium, does result in a somewhat improved fertilizing effect. However, previously used substances have not yet achieved desired results based on the vast numbers of alternative sources of both humic compounds and inorganic complements, as well as the vast number of possible differences in composition and method of preparation. As a result, there has been a need for a compound that is able to deliver both for the benefits of humic compounds and inorganic fertilizers with a high degree of fertilizing efficacy. BRIEF SUMMARY OF THE INVENTION The present invention therefore relates to a fertilizer compound that reduces or eliminates one or more of the drawbacks of traditional inorganic fertilization techniques. The present invention also relates to a fertilizer compound that produces a synergistic affect between inorganic fertilizers and humic compounds. The present invention further relates to a method for producing such a fertilizer compound. Additional details regarding preferred embodiments of the present invention will become evident from the further description provided. DETAILED DESCRIPTION In accordance with the claims, the inventors herein disclose a novel fertilizer compound that reduces the necessity of traditional nitrogen and other inorganic fertilizations. Embodiments of the invention also can contribute to soil quality, water retention, nitrogen retention, and improved aeration. In another aspect, a method of production of a novel fertilizer compound is disclosed by which one or more of the above-described benefits may be obtained. Further detail of the invention will be evident in the additional description herein provided. Humic Fertilizer Composition The claimed fertilizer composition has at least four predominant components. These include nitrogen, phosphoric acid, potassium hydroxide (potash), and an organic component. Preferably, the organic component is either lignite or leonardite. Most preferably, the organic component is lignite. Lignite may be obtained from any appropriate source, such as coal mines or their distributors. The nitrogen in the composition may be obtained from any acceptable source, such as fertilizer dealers, farm cooperatives, and the like. The phosphoric acid is preferably fertilizer grade phosphoric acid, rather than the more highly purified food grade phosphoric acid that is also available. It is believed that this improves the properties of the fertilizer as the fertilizer grade phosphoric acid contains additional impurities which also are sometimes present in soil and utilized by plants in small amounts. The phosphoric acid may be obtained from many chemical companies, such as Hydrite Chemical, or can be produced by various methods, such as that disclosed in U.S. Pat. No. 4,462,972. The potassium hydroxide, or potash, may also be obtained from any acceptable source, such as from any number of chemical companies. The composition herein claimed is preferably a liquid fertilizer. It may contain between about 25% and about 63% nitrogen, between about 10% and about 50% lignite, between about 5% and about 30% phosphoric acid, between about 5% and about 10% potassium hydroxide (potash), and the remainder of the composition water. Preferably, the nitrogen makes up between about 30% to about 55% of the composition, and most preferably between about 40% and about 50% of the composition. These percentages of nitrogen are based upon a 28% liquid solution, and therefore these percentages would change if a solution with a different concentration is utilized. For example, if a 32% liquid solution is used, the fertilizer may contain between about 20% and about 60% nitrogen, preferably between about 25% and about 48%, and most preferably between about 40% and about 46%. Preferably, the lignite makes up between about 15% and about 25% of the composition, and most preferably between about 18% and about 22% of the composition. Also, the lignite is preferably between 50 mesh size and 250 mesh size, and most preferably the lignite is 200 mesh size. The phosphoric acid preferably makes up between about 8% and about 20% of the composition, and most preferably between about 12% and about 15% of the composition. These percentages are based upon a 75% phosphoric acid solution, and as a result the percentages will change if a different concentration solution is used. Also, the phosphoric acid is preferably fertilizer grade. Similarly, the potash preferably makes up between about 6% and about 9% of the composition, and most preferably between about 7% and about 9% of the composition. These percentages are based upon a 45% solution of potash, and as a result the relevant amounts will change if a different concentration is used. The potash may be obtained from any acceptable source, for example from a commercial chemical company such as Hydrite Chemical in Waterloo, Iowa. This composition is applied to the target field preferably at a rate of about one-third gallon per acre. The compound is sprayed much like any other liquid fertilizer, although for best results, a 20 mesh screen should be used in order to minimize clogging of most standard spray applicators. Applying the disclosed compound provides a substantially improved fertilizing effect over and above that expected with other fertilizing compounds, such as nitrogen or other inorganic compounds alone, organic fertilizers alone, or even pre-existing combinations of inorganic or organic compositions in fertilizer compounds. In addition, application of the disclosed compound allows the soil to retain water and other nutrients, which provides at least two beneficial effects. First, it minimizes the likelihood of runoff of fertilizer in areas where the fertilizer is not desired, such as rivers, streams, or groundwater, thereby reducing the potential for negative environmental impact. Also, because various soil nutrients are retained at a higher rate, a lower amount of inorganic fertilizers are required to achieve the same fertilizing effect with future applications of either this fertilizing compound or other inorganic, or combination fertilizing compounds. As a result, the compound herein described provides an unexpectedly high level of benefit to both soil quality and increased fertilizing efficiency, over and above that previously achieved with similar fertilizing compounds. Method of Production In order to produce the above-described compound, it is preferable to use a stainless steel horizontal mixing tank with a mixer installed on each end. First, the nitrogen solution is added to the tank, followed by the lignite. While these ingredients may be added in reverse order, adding the nitrogen first is preferable as the lignite is suspended in the mixture more quickly. The nitrogen and lignite mixture is then mixed at high speed for eight minutes. Then the phosphoric acid is added to the mixture. This also assists with suspension of the composition into a liquid. During this mixing phase, the compound may produce visible vapor. The compound should be mixed about ten to twelve minutes. The water is then added, and the composition is mixed for a further ten minutes. Adding the water at this stage is preferable because it is easier to keep the lignite suspended in the mixture when added after the nitrogen and phosphoric acid. Finally, the potash is added. For safety reasons, it is preferable to add the potash slowly, because if it is added too fast to the mixture an explosive reaction may occur. Adding the potash also increases heat of the compound, and causes a strong odor to be emitted. The potash neutralizes the pH of the mixture, balancing out the phosphoric acid. Once the potash is added, the compound should be mixed for approximately twenty minutes. Once the product is done with the mixing steps, it is then ready for filtration. The product is preferably slowly added to a filter screen, and preferably filtered by gravity flow. The preferred filter size is a between 20 and 70 mesh. A majority of the product will pass through the filter, but a small amount will not pass through. The product that does not pass through should be discarded. Once the compound has been filtered, it may be appropriately packaged for distribution to field sites. When packaging, it is preferable to add a small amount of defoaming agent before filling so that foam is minimized and containers do not have to be refilled after the foam produced in the filling process settles out. The containers may then be sealed and stored for shipment for application. This method of production is preferable to previous methods used in several ways. For example, by adding the water later in the process, the lignite stays suspended more completely in the solution, thereby reducing clumping in the final product, which can cause clogging in the equipment used to spray the compound onto fields. Further, the use of gravity flow through the filter as opposed to a pumping procedure results in a superior product, because changes to the final structure occur when the product is forced through the screen as opposed to letting it naturally proliferate through the screen. It should be understood that the forgoing invention has been described in the context of preferred embodiments, and that modifications apparent to one of ordinary skill in the art are intended to be encompassed within the invention. Further, the scope of the claimed invention should only be limited by the appended claims, not the scope of the specific examples provided herein.

The disclosed invention relates to novel fertilizing compounds comprising a combination of inorganic fertilizers and humic compounds. The combination produces a marked benefit over either type of substance individually, and also over previously known combinations of organic and inorganic fertilizers. The invention also relates to a method of production of such compounds.

[0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/511,319 filed Jul. 25, 2011, which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to RNA interference-based methods for inhibiting the expression of the DUX4 gene, a double homeobox gene on human chromosome 4q35. Recombinant adeno-associated viruses of the invention deliver DNAs encoding microRNAs that knock down the expression of DUX4. The methods have application in the treatment of muscular dystrophies such as facioscapulohumeral muscular dystrophy. INCORPORATION BY REFERENCE OF THE SEQUENCE LISTING [0003] This application contains, as a separate part of disclosure, a Sequence Listing in computer-readable form (filename: 45714PCT_SeqListing.txt; 1,661,020 bytes—ASCII text file) which is incorporated by reference herein in its entirety. BACKGROUND [0004] Muscular dystrophies (MDs) are a group of genetic diseases. The group is characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Some forms of MD develop in infancy or childhood, while others may not appear until middle age or later. The disorders differ in terms of the distribution and extent of muscle weakness (some forms of MD also affect cardiac muscle), the age of onset, the rate of progression, and the pattern of inheritance. [0005] Facioscapulohumeral muscular dystrophy (FSHD) is a complex autosomal dominant disorder characterized by progressive and asymmetric weakness of facial, shoulder and limb muscles. Symptoms typically arise in adulthood with most patients showing clinical features before age thirty. About five percent of patients develop symptoms as infants or juveniles and these are generally more severely affected. Clinical presentation can vary from mild (some limited muscle weakness) to severe (wheelchair dependence). Historically, FSHD was classified as the third most common MD, affecting one in 20,000 individuals worldwide. However, recent data indicate FSHD is the most common MD in Europe, suggesting its worldwide incidence may be underestimated. [0006] Typical FSHD cases (FSHD1A, heretofore referred to as FSHD) are linked to heterozygous chromosomal deletions that decrease the copy number of 3.3 kilobase (kb) D4Z4 repeats on human chromosome 4q35. Simplistically, normal individuals have 11-100 tandemly-repeated D4Z4 copies on both 4q35 alleles, while patients with FSHD have one normal and one contracted allele containing 1-10 repeats. In addition FSHD-associated D4Z4 contractions must occur on specific disease-permissive chromosome 4q35 backgrounds. Importantly, no genes are completely lost or structurally mutated as a result of FSHD-associated deletions. Thus, although the disease was formally classified in 1954, and the primary genetic defect identified in 1992, the pathogenic mechanisms remain unresolved. [0007] In leading FSHD pathogenesis models, D4Z4 contractions are proposed to cause epigenic changes that permit expression of genes with myopathic potential. As a result, aberrant over-expression of otherwise silent or near-silent genes may ultimately cause MD. This model is consistent with data showing normal 4q35 D4Z4 repeats have heterochromatin characteristics, while FSHD-linked D4Z4 repeats contain marks more indicative of actively transcribed euchromatin. These transcription-permissive epigenetic changes, coupled with the observation that complete monosomic D4Z4 deletions (i.e., zero repeats) do not cause FSHD, support the hypothesis that D4Z4 repeats harbor potentially myopathic open reading frames (ORFs), which are abnormally expressed in FSHD muscles. This notion was initially considered in 1994, when a D4Z4-localized ORF, called DUX4, was first identified. However, the locus had some characteristics of an unexpressed pseudogene and DUX4 was therefore summarily dismissed as an FSHD candidate. For many years thereafter, the search for FSHD-related genes was mainly focused outside the D4Z4 repeats, and although some intriguing candidates emerged from these studies, no single gene has been conclusively linked to FSHD development. This slow progress led to the re-emergence of DUX4 as an FSHD candidate in 2007. Even as of 2010 though, researchers continued to highlight other genes as candidates. See, for example, Wuebbles et al., Int. J. Clin. Exp. Pathol., 3(4): 386-400 (2010) highlighting the FSHD region gene 1 (frg1). In contrast. Wallace et al., Mol. Ther., 17(Suppl. 1): S151 (2009); Wei et al., Mol. Ther., 17(Suppl. 1): S200 (2009); and the Lemmers et al. report from the Sciencexpress issue of Aug. 19, 2010 highlight DUX4. Neguembor and Gabellini, Epigenomics, 2(2): 271-287 (2010) is a recent review article regarding FSHD. [0008] RNA interference (RNAi) is a mechanism of gene regulation in eukaryotic cells that has been considered for the treatment of various diseases. RNAi refers to post-transcriptional control of gene expression mediated by microRNAs (miRNAs). The miRNAs are small (21-25 nucleotides), noncoding RNAs that share sequence homology and base-pair with 3′ untranslated regions of cognate messenger RNAs (mRNAs). The interaction between the miRNAs and mRNAs directs cellular gene silencing machinery to prevent the translation of the mRNAs. The RNAi pathway is summarized in Duan (Ed.), Section 7.3 of Chapter 7 in Muscle Gene Therapy , Springer Science+Business Media, LLC (2010). [0009] As an understanding of natural RNAi pathways has developed, researchers have designed artificial miRNAs for use in regulating expression of target genes for treating disease. As described in Section 7.4 of Duan, supra, artificial miRNAs can be transcribed from DNA expression cassettes. The miRNA sequence specific for a target gene is transcribed along with sequences required to direct processing of the miRNA in a cell. Viral vectors such as adeno-associated virus have been used to deliver miRNAs to muscle [Fechner et al., J. Mol. Med., 86: 987-997 (2008)]. [0010] Adeno-associated virus (AAV) is a replication-deficient parvovirus, the single-stranded DNA genome of which is about 4.7 kb in length including 145 nucleotide inverted terminal repeat (ITRs). There are multiple serotypes of AAV. The nucleotide sequences of the genomes of the AAV serotypes are known. For example, the complete genome of AAV-1 is provided in GenBank Accession No. NC_002077; the complete genome of AAV-2 is provided in GenBank Accession No. NC_001401 and Srivastava et al., J. Virol., 45: 555-564 {1983); the complete genome of AAV-3 is provided in GenBank Accession No. NC_1829; the complete genome of AAV-4 is provided in GenBank Accession No. NC_001829; the AAV-5 genome is provided in GenBank Accession No. AF085716; the complete genome of AAV-6 is provided in GenBank Accession No. NC_00 1862; at least portions of AAV-7 and AAV-8 genomes are provided in GenBank Accession Nos. AX753246 and AX753249, respectively; the AAV-9 genome is provided in Gao et al., J. Virol., 78: 6381-6388 (2004); the AAV-10 genome is provided in Mol. Ther., 13(1): 67-76 (2006); and the AAV-11 genome is provided in Virology, 330(2): 375-383 (2004). Cis-acting sequences directing viral DNA replication (rep), encapsidation/packaging and host cell chromosome integration are contained within the AAV ITRs. Three AAV promoters (named p5, p19, and p40 for their relative map locations) drive the expression of the two AAV internal open reading frames encoding rep and cap genes. The two rep promoters (p5 and p19), coupled with the differential splicing of the single AAV intron (at nucleotides 2107 and 2227), result in the production of four rep proteins (rep 78, rep 68, rep 52, and rep 40) from the rep gene. Rep proteins possess multiple enzymatic properties that are ultimately responsible for replicating the viral genome. The cap gene is expressed from the p40 promoter and it encodes the three capsid proteins VP1, VP2, and VP3. Alternative splicing and non-consensus translational start sites are responsible for the production of the three related capsid proteins. A single consensus polyadenylation site is located at map position 95 of the AAV genome. The life cycle and genetics of AAV are reviewed in Muzyczka. Current Topics in Microbiology and Immunology, 158: 97-129 (1992). [0011] AAV possesses unique features that make it attractive as a vector for delivering foreign DNA to cells, for example, in gene therapy. AAV infection of cells in culture is noncytopathic, and natural infection of humans and other animals is silent and asymptomatic. Moreover, AAV infects many mammalian cells allowing the possibility of targeting many different tissues in vivo. Moreover, AAV transduces slowly dividing and non-dividing cells, and can persist essentially for the lifetime of those cells as a transcriptionally active nuclear episome (extrachromosomal element). The AAV proviral genome is infectious as cloned DNA in plasmids which makes construction of recombinant genomes feasible. Furthermore, because the signals directing AAV replication, genome encapsidation and integration are contained within the ITRs of the AAV genome, some or all of the internal approximately 4.3 kb of the genome (encoding replication and structural capsid proteins, rep-cap) may be replaced with foreign DNA. The rep and cap proteins may be provided in trans. Another significant feature of AAV is that it is an extremely stable and hearty virus. It easily withstands the conditions used to inactivate adenovirus (56° to 65° C. for several hours), making cold preservation of AAV less critical. AAV may even be lyophilized. Finally, AAV-infected cells are not resistant to superinfection. [0012] There remains a need in the art for a treatment for muscular dystrophies including FSHD. SUMMARY [0013] The present invention provides methods and products for preventing or inhibiting the expression of the DUX4 gene. The methods of the invention utilize RNAi to prevent or inhibit the expression of the DUX4 gene. The methods involve delivering inhibitory RNAs specific for the DUX4 gene to muscle cells. The DUX4 inhibitory RNAs contemplated include, but are not limited to, antisense RNAs, small inhibitory RNAs (siRNAs), short hairpin RNAs (shRNAs) or artificial microRNAs (DUX4 miRNAs) that inhibit expression of DUX4. Use of the methods and products is indicated, for example, in preventing or treating FSHD. Some embodiments of the invention exploit the unique properties of AAV to deliver DNA encoding DUX4 inhibitory RNAs to muscle cells. Other embodiments of the invention utilize other vectors (for example, other viral vectors such as adenovirus, retrovirus, lentivirus, equine-associated virus, alphavirus, pox viruses, herpes virus, polio virus, sindbis virus and vaccinia viruses) to deliver polynucleotides encoding DUX4 inhibitory RNAs. [0014] In one aspect, the invention provides DUX4 miRNAs. In another aspect, the invention provides rAAV encoding the DUX4 miRNAs wherein the rAAV lack rep and cap genes. In some embodiments, the DUX4 miRNA comprises an miRNA antisense guide strand selected from those set out in SEQ ID NO: 10 through SEQ ID NO: 10912. These sequences comprise antisense “guide” strand sequences of the invention of varying sizes. The antisense guide strand is the strand of the mature miRNA duplex that becomes the RNA component of the RNA induced silencing complex ultimately responsible for sequence-specific gene silencing. See Section 7.3 of Duan, supra. For example, the first antisense guide strand in SEQ ID NO: 10 corresponds to (is the reverse complement of) the 3′ end of the DUX4 sequence set out in FIG. 1 . The second antisense guide strand (SEQ ID NO: 11) is offset one nucleotide from the first and so on. In some embodiments, the GC content of the antisense guide strand is 60% or less, and/or the 5′ end of the antisense guide strand is more AU rich while the 3′ end is more GC rich. Exemplified DUX4 miRNA are encoded by the DNAs are set out in SEQ ID NOs: 1 and 2. [0015] In another aspect, the invention provides a composition comprising a rAAV encoding a DUX4 miRNA (for example, a rAAV comprising the DNA set out in SEQ ID NO: 1 or 2) wherein the rAAV lacks rep and cap genes. [0016] In yet another aspect, the invention provides a method of preventing or inhibiting expression of the DUX4 gene in a cell comprising contacting the cell with a rAAV encoding a DUX4 miRNA (for example, a rAAV comprising the DNA set out in SEQ ID NO: 1 or 2) wherein the rAAV lacks rep and cap genes. Expression of DUX4 may be inhibited by at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 or 99 percent. [0017] In still another aspect, the invention provides a method of delivering DNA encoding a DUX4 miRNA to an animal in need thereof, comprising administering to the animal a rAAV a DUX4 miRNA (for example, a rAAV comprising the DNA set out in SEQ ID NO: 1 or 2) wherein the rAAV lacks rep and cap genes. [0018] In yet another aspect, the invention provides a method of preventing or treating a muscular dystrophy (including, but not limited to, FSHD) comprising administering a rAAV encoding a DUX4 miRNA (for example, a rAAV comprising the DNA set out in SEQ ID NO: 1 or 2) wherein the rAAV lacks rep and cap genes. “Treating” includes ameliorating one or more symptoms of the muscular dystrophy (such as FSHD). Molecular, biochemical, histological and functional endpoints demonstrate the therapeutic efficacy of DUX4 miRNAs. Endpoints contemplated by the invention include one or more of: the reduction or elimination of DUX4 protein in affected muscles, DUX4 gene knockdown, increase in myofiber diameters, and improvement in muscle strength. DETAILED DESCRIPTION [0019] Recombinant AAV genomes of the invention comprise one or more AAV ITRs flanking a polynucleotide encoding, for example, one or more DUX4 miRNAs. The polynucleotide is operatively linked to transcriptional control DNA, specifically promoter DNA that is functional in target cells. Commercial providers such as Ambion Inc. (Austin, Tex.), Darmacon Inc. (Lafayette, Colo.), InvivoGen (San Diego, Calif.), and Molecular Research Laboratories. LLC (Herndon, Va.) generate custom inhibitory RNA molecules. In addition, commercially kits are available to produce custom siRNA molecules, such as SILENCER™ siRNA Construction Kit (Ambion Inc., Austin, Tex.) or psiRNA System (InvivoGen, San Diego, Calif.). Embodiments include a rAAV genome comprising the DNA set out in SEQ ID NO: 1 encoding the DUX4 miRNA named “miDux4.405” and a rAAV genome comprising the DNA set out in SEQ ID NO: 2 encoding the DUX4 miRNA named “miDux4.1156.” [0020] The rAAV genomes of the invention lack AAV rep and cap DNA. AAV DNA in the rAAV genomes may be from any AAV serotype for which a recombinant virus can be derived including, but not limited to, AAV serotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, AAV-9, AAV-10 and AAV-11. As noted in the Background section above, the nucleotide sequences of the genomes of various AAV serotypes are known in the art. [0021] DNA plasmids of the invention comprise rAAV genomes of the invention. The DNA plasmids are transferred to cells permissible for infection with a helper virus of AAV (e.g., adenovirus, E1-deleted adenovirus or herpesvirus) for assembly of the rAAV genome into infectious viral particles. Techniques to produce rAAV particles, in which an AAV genome to be packaged, rep and cap genes, and helper virus functions are provided to a cell are standard in the art. Production of rAAV requires that the following components are present within a single cell (denoted herein as a packaging cell): a rAAV genome, AAV rep and cap genes separate from (i.e., not in) the rAAV genome, and helper virus functions. The AAV rep and cap genes may be from any AAV serotype for which recombinant virus can be derived and may be from a different AAV serotype than the rAAV genome ITRs, including, but not limited to, AAV serotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, AAV-9, AAV-10 and AAV-11. Production of pseudotyped rAAV is disclosed in, for example, WO 01/83692 which is incorporated by reference herein in its entirety. [0022] A method of generating a packaging cell is to create a cell line that stably expresses all the necessary components for AAV particle production. For example, a plasmid (or multiple plasmids) comprising a rAAV genome lacking AAV rep and cap genes, AAV rep and cap genes separate from the rAAV genome, and a selectable marker, such as a neomycin resistance gene, are integrated into the genome of a cell. AAV genomes have been introduced into bacterial plasmids by procedures such as GC tailing (Samulski et al., 1982, Proc. Natl. Acad. S6. USA, 79:2077-2081), addition of synthetic linkers containing restriction endonuclease cleavage sites (Laughlin et al., 1983, Gene, 23:65-73) or by direct, blunt-end ligation (Senapathy & Carter, 1984, J. Biol. Chem., 259:4661-4666). The packaging cell line is then infected with a helper virus such as adenovirus. The advantages of this method are that the cells are selectable and are suitable for large-scale production of rAAV. Other examples of suitable methods employ adenovirus or baculovirus rather than plasmids to introduce rAAV genomes and/or rep and cap genes into packaging cells. [0023] General principles of rAAV production are reviewed in, for example, Carter, 1992, Current Opinions in Biotechnology, 1533-539; and Muzyczka, 1992, Curr. Topics in Microbial. and Immunol., 158:97-129). Various approaches are described in Ratschin et al., Mol. Cell. Biol. 4:2072 (1984); Hermonat et al., Proc. Natl. Acad. Sci. USA, 81:6466 (1984); Tratschin et al., Mol. Cell. Biol. 5:3251 (1985); McLaughlin et al., J. Virol., 62:1963 (1988); and Lebkowski et al., 1988 Mol. Cell. Biol., 7:349 (1988). Samulski et al. (1989, J. Virol., 63:3822-3828); U.S. Pat. No. 5,173,414; WO 95/13365 and corresponding U.S. Pat. No. 5,658,776; WO 95/13392; WO 96/17947; PCT/US98/18600; WO 97/09441 (PCT/U596/14423); WO 97/08298 (PCT/U596/13872); WO 97/21825 (PCT/U596/20777); WO 97/06243 (PCT/FR96/01064); WO 99/11764; Perrin et al. (1995) Vaccine 13:1244-1250; Paul et al. (1993) Human Gene Therapy 4:609-615; Clark et al. (1996) Gene Therapy 3:1124-1132; U.S. Pat. No. 5,786,211; U.S. Pat. No. 5,871,982; and U.S. Pat. No. 6,258,595. The foregoing documents are hereby incorporated by reference in their entirety herein, with particular emphasis on those sections of the documents relating to rAAV production. [0024] The invention thus provides packaging cells that produce infectious rAAV. In one embodiment packaging cells may be stably transformed cancer cells such as HeLa cells, 293 cells and PerC.6 cells (a cognate 293 line). In another embodiment, packaging cells are cells that are not transformed cancer cells, such as low passage 293 cells (human fetal kidney cells transformed with E1 of adenovirus), MRC-5 cells (human fetal fibroblasts), WI-38 cells (human fetal fibroblasts), Vero cells (monkey kidney cells) and FRhL-2 cells (rhesus fetal lung cells). [0025] Recombinant AAV (i.e., infectious encapsidated rAAV particles) of the invention comprise a rAAV genome. Embodiments include, but are not limited to, the rAAV named “AAV.miDUX4.405” including a genome encoding the DUX4 miRNA hDux.mi405 (encoded by the DNA set out in SEQ ID NO: 1 and the rAAV named “AAV.miDUX4.1156” including a genome encoding the DUX4 miRNA hDux.mi1156 (encoded by the DNA set out in SEQ ID NO: 2). The genomes of both rAAV lack AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genomes. [0026] The rAAV may be purified by methods standard in the art such as by column chromatography or cesium chloride gradients. Methods for purifying rAAV vectors from helper virus are known in the art and include methods disclosed in, for example, Clark et al., Hum. Gene Ther., 10(6): 1031-1039 (1999); Schenpp and Clark, Methods Mol. Med., 69 427-443 (2002); U.S. Pat. No. 6,566,118 and WO 98/09657. [0027] In another embodiment, the invention contemplates compositions comprising rAAV of the present invention. Compositions of the invention comprise rAAV in a pharmaceutically acceptable carrier. The compositions may also comprise other ingredients such as diluents and adjuvants. Acceptable carriers, diluents and adjuvants are nontoxic to recipients and are preferably inert at the dosages and concentrations employed, and include buffers such as phosphate, citrate, or other organic acids; antioxidants such as ascorbic acid; low molecular weight polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as Tween, pluronics or polyethylene glycol (PEG). [0028] Titers of rAAV to be administered in methods of the invention will vary depending, for example, on the particular rAAV, the mode of administration, the treatment goal, the individual, and the cell type(s) being targeted, and may be determined by methods standard in the art. Titers of rAAV may range from about 1×10 6 , about 1×10 7 , about 1×10 8 , about 1×10 9 , about 1×10 10 , about 1×10 11 , about 1×10 12 , about 1×10 13 to about 1×10 14 or more DNase resistant particles (DRP) per ml. Dosages may also be expressed in units of viral genomes (vg). [0029] Methods of transducing a target cell with rAAV, in vivo or in vitro, are contemplated by the invention. The in vivo methods comprise the step of administering an effective dose, or effective multiple doses, of a composition comprising a rAAV of the invention to an animal (including a human being) in need thereof. If the dose is administered prior to development of a disorder/disease, the administration is prophylactic. If the dose is administered after the development of a disorder/disease, the administration is therapeutic. In embodiments of the invention, an effective dose is a dose that alleviates (eliminates or reduces) at least one symptom associated with the disorder/disease state being treated, that slows or prevents progression to a disorder/disease state, that slows or prevents progression of a disorder/disease state, that diminishes the extent of disease, that results in remission (partial or total) of disease, and/or that prolongs survival. An example of a disease contemplated for prevention or treatment with methods of the invention is FSHD. [0030] Combination therapies are also contemplated by the invention. Combination as used herein includes both simultaneous treatment or sequential treatments. Combinations of methods of the invention with standard medical treatments (e.g., corticosteroids) are specifically contemplated, as are combinations with novel therapies. [0031] Administration of an effective dose of the compositions may be by routes standard in the art including, but not limited to, intramuscular, parenteral, intravenous, oral, buccal, nasal, pulmonary, intracranial, intraosseous, intraocular, rectal, or vaginal. Route(s) of administration and serotype(s) of AAV components of the rAAV (in particular, the AAV ITRs and capsid protein) of the invention may be chosen and/or matched by those skilled in the art taking into account the infection and/or disease state being treated and the target cells/tissue(s) that are to express the DUX4 miRNAs. [0032] In particular, actual administration of rAAV of the present invention may be accomplished by using any physical method that will transport the rAAV recombinant vector into the target tissue of an animal. Administration according to the invention includes, but is not limited to, injection into muscle, the bloodstream and/or directly into the liver. Simply resuspending a rAAV in phosphate buffered saline has been demonstrated to be sufficient to provide a vehicle useful for muscle tissue expression, and there are no known restrictions on the carriers or other components that can be co-administered with the rAAV (although compositions that degrade DNA should be avoided in the normal manner with rAAV). Capsid proteins of a rAAV may be modified so that the rAAV is targeted to a particular target tissue of interest such as muscle. See, for example, WO 02/053703, the disclosure of which is incorporated by reference herein. Pharmaceutical compositions can be prepared as injectable formulations or as topical formulations to be delivered to the muscles by transdermal transport. Numerous formulations for both intramuscular injection and transdermal transport have been previously developed and can be used in the practice of the invention. The rAAV can be used with any pharmaceutically acceptable carrier for ease of administration and handling. [0033] For purposes of intramuscular injection, solutions in an adjuvant such as sesame or peanut oil or in aqueous propylene glycol can be employed, as well as sterile aqueous solutions. Such aqueous solutions can be buffered, if desired, and the liquid diluent first rendered isotonic with saline or glucose. Solutions of rAAV as a free acid (DNA contains acidic phosphate groups) or a pharmacologically acceptable salt can be prepared in water suitably mixed with a surfactant such as hydroxpropylcellulose. A dispersion of rAAV can also be prepared in glycerol, liquid polyethylene glycols and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms. In this connection, the sterile aqueous media employed are all readily obtainable by standard techniques well-known to those skilled in the art. [0034] The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating actions of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, liquid polyethylene glycol and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of a dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal and the like. In many cases it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by use of agents delaying absorption, for example, aluminum monostearate and gelatin. [0035] Sterile injectable solutions are prepared by incorporating rAAV in the required amount in the appropriate solvent with various other ingredients enumerated above, as required, followed by filter sterilization. Generally, dispersions are prepared by incorporating the sterilized active ingredient into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying technique that yield a powder of the active ingredient plus any additional desired ingredient from the previously sterile-filtered solution thereof. [0036] Transduction with rAAV may also be carried out in vitro. In one embodiment, desired target muscle cells are removed from the subject, transduced with rAAV and reintroduced into the subject. Alternatively, syngeneic or xenogeneic muscle cells can be used where those cells will not generate an inappropriate immune response in the subject. [0037] Suitable methods for the transduction and reintroduction of transduced cells into a subject are known in the art. In one embodiment, cells can be transduced in vitro by combining rAAV with muscle cells, e.g., in appropriate media, and screening for those cells harboring the DNA of interest using conventional techniques such as Southern blots and/or PCR, or by using selectable markers. Transduced cells can then be formulated into pharmaceutical compositions, and the composition introduced into the subject by various techniques, such as by intramuscular, intravenous, subcutaneous and intraperitoneal injection, or by injection into smooth and cardiac muscle, using e.g., a catheter. [0038] Transduction of cells with rAAV of the invention results in sustained expression of DUX4 miRNAs. The present invention thus provides methods of administering/delivering rAAV which express DUX4 miRNAs to an animal, preferably a human being. These methods include transducing tissues (including, but not limited to, tissues such as muscle, organs such as liver and brain, and glands such as salivary glands) with one or more rAAV of the present invention. Transduction may be carried out with gene cassettes comprising tissue specific control elements. For example, one embodiment of the invention provides methods of transducing muscle cells and muscle tissues directed by muscle specific control elements, including, but not limited to, those derived from the actin and myosin gene families, such as from the myoD gene family [See Weintraub et al., Science, 251: 761-766 (1991)], the myocyte-specific enhancer binding factor MEF-2 [Cserjesi and Olson, Mol Cell Biol 11: 4854-4862 (1991)], control elements derived from the human skeletal actin gene [Muscat et al., Mol Cell Biol, 7: 4089-4099 (1987)], the cardiac actin gene, muscle creatine kinase sequence elements [See Johnson et al., Mol Cell Biol, 9:3393-3399 (1989)] and the murine creatine kinase enhancer (mCK) element, control elements derived from the skeletal fast-twitch troponin C gene, the slow-twitch cardiac troponin C gene and the slow-twitch troponin I gene: hypoxia-inducible nuclear factors [Semenza et al., Proc Natl Acad Sci USA, 88: 5680-5684 (1990], steroid-inducible elements and promoters including the glucocorticoid response element (GRE) [See Mader and White, Proc. Natl. Acad. Sci. USA 90: 5603-5607 (1993)], and other control elements. [0039] Muscle tissue is an attractive target for in vivo DNA delivery, because it is not a vital organ and is easy to access. The invention contemplates sustained expression of miRNAs from transduced myofibers. [0040] By “muscle cell” or “muscle tissue” is meant a cell or group of cells derived from muscle of any kind (for example, skeletal muscle and smooth muscle, e.g. from the digestive tract, urinary bladder, blood vessels or cardiac tissue). Such muscle cells may be differentiated or undifferentiated, such as myoblasts, myocytes, myotubes, cardiomyocytes and cardiomyoblasts. [0041] The term “transduction” is used to refer to the administration/delivery of DUX4 miRNAs to a recipient cell either in vivo or in vitro, via a replication-deficient rAAV of the invention resulting in expression of a DUX4 miRNA by the recipient cell. [0042] Thus, the invention provides methods of administering an effective dose (or doses, administered essentially simultaneously or doses given at intervals) of rAAV that encode DUX4 miRNAs to a patient in need thereof. BRIEF DESCRIPTION OF THE DRAWING [0043] FIG. 1 shows the human DUX4 DNA sequence. [0044] FIGS. 2A and 2B set out sequences of DUX4 targeted miRNAs. In each panel, the top sequences indicate the DNA templates from which each respective miRNA is transcribed. In the top panel, the DNA template miDUX4.405 is SEQ ID NO: 1. In the bottom panel, the DNA template miDUX4.1156 is SEQ ID NO: 2. The folded miRNA transcripts are shown as hairpin structures. The miDUX4.405 folded miRNA is SEQ ID NO: 8. The miDUX4.1156 folded miRNA is SEQ ID NO: 9. The mature miDUX4.405 and miDUX4.1156 sequences arise following processing in target cells by host miRNA processing machinery (including Drosha. DGCR8, Dicer, and Exportin-5). Sequences shaded in gray indicate restriction sites used for cloning each miRNA into the U6T6 vector. CTCGAG is an XhoI site and ACTAGT is a SpeI site (CUCGAG and ACUAGU in RNA, where the U is a uracil base). The red sequence indicates the mature miRNA antisense guide strand that ultimately helps catalyze cleavage of the DUX4 target mRNA. This sequence is also underlined in the miRNA hairpin portions of this diagram. The gray and black arrowheads indicate Drosha- and Dicer-catalyzed cleavage sites, respectively. The numbers 13, 35, 53, and 75 are provided for orientation. The sequences between (and including) positions 35-53 are derived from the natural human mir-30a sequence, except the A at position 39, which is a G is the normal mir-30a sequence. We changed this nucleotide to an A to facilitate folding of the miRNA loop, based on in silico RNA folding models. The base of the stem (5′ of position 13 and 3′ of position 75) is also derived from mir-30a structure and sequence with some modifications depending on the primary sequence of the guide strand. Specifically, the nucleotide at position 13 can vary to help facilitate a required mismatched between the position 13 and 75 nucleotides. This bulged structure is hypothesized to facilitate proper Drosha cleavage. [0045] FIG. 3 relates to a luciferase assay used for initial miDUX4 efficacy screens. FIG. 3A shows the dual luciferase reporter plasmid used for in vitro screens. This vector is modified from a commercially available plasmid (psiCheck2) obtained from Promega. The human DUX4 cDNA was cloned downstream of the Renilla luciferase gene, as shown. This conformation does not produce a Luciferase-DUX4 fusion protein, since the DUX4 sequences are placed after the Renilla luciferase stop codon. Instead, a fusion mRNA is produced, in which the DUX4 sequences are the de facto 3′ untranslated region (3′ UTR) of Renilla luciferase. As a result, any effective DUX4-targeted miRNA will reduce the Renilla Luciferase-DUX4 fusion mRNA, which subsequently decreases Renilla luciferase protein expression in transfected cells. There is a separate Firefly luciferase gene located on the same plasmid, which does not contain any DUX4 sequences and is therefore unaffected by DUX4-targeted miRNAs. FIG. 3B shows Firefly and Renilla luciferase activity quantified separately in cells using a Dual Luciferase Assay Kit (Promega). DUX4 gene silencing is therefore measured indirectly and indicated by a low ratio of Renilla :Firefly luciferase activity. All samples in this assay are normalized to cells co-transfected with our reporter vector and the U6.miGFP control miRNA. Samples transfected with miDUX4.405 and miDUX4.1156 had consistently lower Renilla luciferase activity, indicating DUX4 gene silencing. Data in B are representative of two independent experiments performed on different days in triplicate. Error bars indicate standard error of the mean (s.e.m.). [0046] FIG. 4A is a diagram of constructs used in Western blot experiments showing AAV.miDUX4 proviral plasmids reduce DUX4 protein expression in vitro. In the diagram of the constructs, the black rectangles indicate AAV inverted terminal repeats (ITRs), CMV is the cytomegalovirus promoter, hrGFP is a green fluorescent protein coding region, pA is the SV40 polyA signal and V5 refers to the V5 epitope which was inserted in frame at the C terminus of human DUX4 to facilitate detection with commercially available V5 epitope antibodies (Invitrogen). The U6.miDUX4 sequences (405 and 1156) and U6.miGFP control were cloned upstream of the CMV.hrGFP.pA cassette, as shown. Proviral plasmids were co-transfected into HEK293 cells with the CMV.DUX4.V5 expression vector shown at the top of FIG. 4A . FIG. 4B shows Western blots using antibodies targeting the V5 epitope (DUX4) demonstrating DUX4 gene silencing by both miDUX4 sequences, compared to the non-targeting miGFP control. GAPDH antibodies were used to control for equivalent loading of protein extracts for the experiment. The Tint′ lane contains protein extracts from untransfected HEK293 cells. [0047] FIG. 5 is a diagram of genomes of rAAV encoding DUX4 miRNAs. EXAMPLES [0048] The role of DUX4 in FSHD pathogenesis can be explained as follows. First, D4Z4 repeats are not pseudogenes. The DUX4 locus produces 1.7 kb and 2.0 kb full-length mRNAs with identical coding regions, and D4Z4 repeats also harbor smaller sense and antisense transcripts, including some resembling microRNAs. Over-expressed DUX4 transcripts and a ˜50 kDa full-length DUX4 protein are found in biopsies and cell lines from FSHD patients. These data are consistent with a transcriptional de-repression model of FSHD pathogenesis. In addition, unlike pseudogenes, D4Z4 repeats and DUX4 likely have functional importance, since tandemly-arrayed D4Z4 repeats are conserved in at least eleven different placental mammalian species (non-placental animals lack D4Z4 repeats), with the greatest sequence conservation occurring within the DUX4 ORF. Second, over-expressed DUX4 is toxic to tissue culture cells and embryonic progenitors of developing lower organisms in vivo. This toxicity occurs at least partly through a pro-apoptotic mechanism, indicated by Caspase-3 activation in DUX4 transfected cells, and presence of TUNEL-positive nuclei in developmentally arrested Xenopus embryos injected with DUX4 mRNA at the two-cell stage. These findings are consistent with studies showing some pro-apoptotic proteins, including Caspase-3, are present in FSHD patient muscles. In addition to stimulating apoptosis, DUX4 may negatively regulate myogenesis. Human DUX4 inhibits differentiation of mouse C2C12 myoblasts in vitro, potentially by interfering with PAX3 and/or PAX7, and causes developmental arrest and reduced staining of some muscle markers when delivered to progenitor cells of zebrafish or Xenopus embryos. Finally, aberrant DUX4 function is directly associated with potentially important molecular changes seen in FSHD patient muscles. Specifically, full-length human DUX4 encodes an approximately 50 kDa double homeodomain transcription factor, and its only known target, Pitx1, was elevated in DUX4 over-expressing FSHD patient muscles. These data support that DUX4 catalyzes numerous downstream molecular changes that are incompatible with maintaining normal muscle integrity. [0049] Thus, aspects and embodiments of the invention are illustrated by the following examples. Example 1 describes miRNAs specific for the DUX4 gene. Example 2 describes the effect of the miRNAs on the expression of DUX4 as measured by luciferase assay. Example 3 describes the in vitro effect of proviral plasmids expressing the miRNAs on the expression of DUX4 as measured by Western blot. Example 4 describes rAAV vectors encoding DUX4 miRNAs. Example 5 describes mitigation of DUX4-induced myopathy by AAV6.miDUX4.405 vectors. Example 6 describes protection of muscles from pathological muscles changes associated with FSHD. Example 7 describes the protection of mice from DUX4-associated grip strength deficits. Example 1 MicroRNAs Specific for the DUX4 Gene [0050] Two miRNAs specific for the DUX4 gene were generated by PCR. Four PCR primers were used that had the following sequences. [0000] Primer 662 (miDUX4hum405F): (SEQ ID NO: 3) AAAACTCGAGTGAGCGATCCAGGATTCAGATCTGGTTTCTGAAAGCCACA GATGGG Primer 663 (miDUX4hum405R): (SEQ ID NO: 4) TTTTACTAGTAGGCAGTCCAGGATTCAGATCTGGTTTCCCATCTGTGGCT TTCAG Primer 665 (miDUX4hum1156F): (SEQ ID NO: 5) AAAACTCGAGTGAGCGAAGGCGCAACCTCTCCTAGAAACTGAAAGCCACA GATGGG Primer 667 (miDUX4hum1156R): (SEQ ID NO: 6) TTTTACTAGTAGGCACAGGCGCAACCTCTCCTAGAAACCCATCTGTGGCT TTCAG [0051] DNA encoding a miRNA designated hDux.mi405 was generated using primers 662 and 663. DNA encoding miRNA designated hDux.mi1156 was generated using primers 665 and 667. [0052] One μg of each primer was added to a 1 cycle primer extension reaction: 95° C. for 5 min.; 94° C. for 2 min.; 52° C. for 1 min.; 72° C. for 15 min.; and then holding at 4° C. The PCR products were cleaned up with the Qiagen QIAquick PCR Purification kit before being digested overnight with XHOI and SPEI restriction enzymes. The digestion product was then run on a 1.5% TBE gel and the band excised and purified using the Qiagen QIAquick Gel Extraction Kit. The sequences of the miRNAs are set out below and in FIGS. 2A and 2B , respectively. [0000] miDux4.405 (SEQ ID NO: 1) CTCGAGT GAGCGATCCAGGATTCAGATCTGGTTTCTGAAAGCCACAGATG GGAAACCAGATCTGAATCCTGGACTGCCT ACTAGT miDux4.1156 (SEQ ID NO: 2) CTCGAGT GAGCGAAGGCGCAACCTCTCCTAGAAACTGAAAGCCACAGATG GGTTTCTAGGAGAGGTTGCGCCTGTGCCT ACTAGT [0053] The two PCR products were ligated overnight to a U6T6 vector (via XhoI and XbaI) that contains a mouse U6 promoter and an RNA polymerase III termination signal (six thymidine nucleotides). MiRNAs are cloned into XhoI and XbaI restriction sites located between the 3′ end of the U6 promoter and termination signal (SpeI site on the 3′ end of the DNA template for each miRNA has complementary cohesive ends with the XbaI site). The ligation product was transformed into chemically competent E - coli cells with a 42° C. heat shock and incubated at 37° C. shaking for 1 hour before being plated on kanamycin selection plates. The colonies were allowed to grow overnight at 37°. The following day they were mini-prepped and sequenced for accuracy. Example 2 Luciferase Assay for Effect of Expression of DUX4 miRNAs [0054] Expression of the DUX4 target sequence in the presence of the DUX4 miRNAs was assayed. A lipofectamine 2000 transfection was done in 293 cells in a 96-well, white-walled assay plate. 140,000 cells were transfected with 20 ng of a Renilla -firefly plasmid containing the DUX4 target sequence ( FIG. 3A ) and 180 ng of various DUX4 miRNA-encoding vectors, including U6T6-driven miDux4.405 or miDux4.1156 vectors from Example 1. A luciferase assay was performed 24 hours later. [0055] The media was removed from the cells and 20 μl of lysis buffer was added per well. The plate was put on a shaker for 15 minutes at room temperature before adding 50 μl of luciferase substrate. The first reading was taken 10 minutes later. Next, 50 μl of Stop and Glo luciferase substrate was added and the second reading was taken 10 minutes later. The Renilla expression was divided by the firefly expression to calculate the relative expression. The relative expression was then normalized to the expression of cells that were transfected with a control miRNA that targets eGFP. Results are shown in FIG. 3B . The DUX4 miRNAs miDUX4.405 and miDUX4.1156 were the most effective at reducing luciferase protein expression in transfected cells. Example 3 Western Blot Assay for Effect of Expression of DUX4 miRNAs from rAAV [0056] Next, the U6T6.miDUX4 miRNA expression cassettes were cloned into AAV.CMV.hrGFP proviral plasmids as shown in the FIG. 4A . The proviral plasmids were then co-transfected with a DUX4.V5 expression plasmid into 293 cells and the effect of expression of DUX4 miRNAs from the proviral plasmids was assayed by Western blot. A U6.miGFP sequence, which does not target DUX4, was used as a negative control for gene silencing. [0057] One day before transfection, 293 cells were plated in a 24-well plate at 1.5×10 5 cells/well. The cells were then transfected with AAV-CMV-DUX4-V5 and AAV-CMV-miDUX4 (405 or 1156) using Lipofectamine 2000 (Invitrogen, Cat. No. 11668-019): [0000] Group 1: AAV-CMV-DUX4-V5 50 ng+AAV-CMV-miDUX4 800 ng (1:16) Group 2: AAV-CMV-DUX4-V5 100 ng+AAV-CMV-miDUX4 800 ng (1:8) [0058] Thirty-six h after transfection, cells were collected and washed with cold PBS once. Seventy μl lysis buffer (137 mM NaCl, 10 mM Tris pH=7.4, 1% NP40) were then added. The cells were resuspended completely and incubated on ice for 30 min. The samples were centrifuged for 20 min at 13,000 rpm at 4° C. and the supernatant was collected. The cell lysate was diluted 5-fold for the Lowry protein concentration assay (Bio-Rad Dc Protein Assay Reagent A, B. S; Cat. No. 500-0113, 500-0114, 500-115). Twenty-three μg of each sample was taken and 2× sample buffer (100 mM Tris pH=6.8, 100 mM DTT, 10% glycerol, 2% SDS, 0.006% bromophenol blue) was added. The samples were boiled for 10 min and then put on ice. [0059] The samples were loaded onto 10% polyacrylamide gels (based on 37.5:1 acrylamide:bis acrylamide ratio, Bio-Rad, Cat. No. 161-0158), 3.5 μg and 18 μg on two gels for each sample. Proteins were transferred to PVDF membranes at 15 V for 1 h using semi-dry transfer (Trans-Blot SD Semi-Dry Transfer Cell, Bio-Rad, Cat. No. 170-3940). The blots were placed into blocking buffer (5% non-fat dry milk, 30 mM Tris pH=7.5, 150 mM NaCl, 0.05% Tween-20) and agitated for 1 h at room temperature. The blocking buffer was decanted and anti-DUX4 primary antibody solution (DUX4 p12, Santa Cruz, Cat. No. sc-79927, 1:1,000) was added and incubated with agitation overnight at 4° C. The membranes were then washed for 30 min, changing the wash buffer (150 mM NaCl, 30 mM Tris pH=7.5, 0.05% Tween-20) every 10 min. Peroxidase-conjugated Donkey Anti-Goat Antibody (Jackson ImmunoReserch, Cat. No. 705-035-003, 1:100,000) was added and incubated at room temperature for 2 h. The membranes were then washed for 30 min, changing the wash buffer every 10 min. The blots were placed in chemiluminescent working solution (Immobilon Western Chemiluminescent HRP Substrate, Millipore, Cat. No. WBKLS0500), incubated with agitation for 5 mm at room temperature, and then exposed to X-ray film. [0060] The membranes were washed for 20 min, changing the wash buffer every 10 min. Next, stripping buffer (2% SDS, 62.5 mM Tris pH=6.7, 100 mM b-ME) was added to the blots and incubated at 50° C. for 30 mm. The membranes were washed again for 30 min, changing the wash buffer every 10 mm. Then, the membranes were blocked again and re-probed with Anti-GAPDH primary antibody solution (Chemicon, Cat. No. MAB374, 1:200) and peroxidase-conjugated Goat Anti-Mouse Antibody (Jackson ImmunoReserch, Cat. No. 115-035-146, 1:100,000) was used as secondary antibody. [0061] Finally, the membranes were stripped again and re-probed with anti-V5 antibody (Invitrogen, Cat. No. R960-25, 1:5,000). [0062] The AAV.miDUX4 proviral plasmids reduced DUX4 protein expression in vitro. AAV-CMV-miDUX4.405 was the most effective at knocking down DUX4 expression. Example 4 Production of rAAV Encoding DUX4 MicroRNAs [0063] Vector was produced by co-transfection in HEK293 cells of three plasmids (pAdhelper, AAV helper, and the rAAV genome containing miDUX4; described in detail below), followed by cell-harvesting, vector purification, titration, and quality control assays. [0064] Plasmids: [0065] pAdhelper contains the adenovirus genes E2A, E4 ORF6, and VA I/II; AAV helper plasmids contain AAV rep2 and cap6 (for example, for an AAV serotype 6 preparation, the capsid gene would be called cap6); the rAAV plasmid contains AAV inverted terminal repeat (ITRs) sequences flanking the genetic elements to be packaged into the vector. For the AAV.miDUX4, this includes the U6.miDUX4 cloned upstream of the CMV.eGFP reporter gene. [0066] Transfection: Plasmids were transfected into 293 cells (Corning 10-Stack) using CaPO 4 at a 4:4:1 ratio (20 μg pAd helper:20 μg AAV helper:5 μg rAAV vector plasmid per plate. [0067] Cell Harvesting: [0068] Forty-eight hr post-transfection, cells were harvested and resuspended in 20 mM Tris (pH 8.0), 1 mM MgCl 2 and 150 mM NaCl (T20M1N150) at a density of 5×10 6 cells/ml. Cells were lysed by four sequential freeze/thaw cycles and Benzonase nuclease (AIC, Stock: 250 U/ul) added to a final concentration of 90 U/ml before cell lysate clarification. [0069] Vector Purification and Titration: [0070] Clarified lysates were subjected to iodixanol step gradient purification as previously described (Xiao, X, et al. J. Virol 72:2224-32). The 40% iodixanol layer (containing rAAV) was diluted 5-fold with a no-salt dilution buffer (pH varying depending on serotype) and applied to a Hi-Trap HP-Q/S column. Upon elution with a NaCl salt gradient, peak 1 ml fractions (typically 3-5) were pooled, dialyzed with T20MIN200 (pH 8.0), then sterile filtered and supplemented with 0.001% Pluronic F68. Vector was stored at −80° C. Purified virus was titered for vg using Q-PCR as previously described [Schnepp and Clark, Methods Mol. Med., 69:427-443 (2002)]. [0071] Schematic diagrams of the rAAV genomes are shown in FIG. 5 . Example 5 AAV6.miDUX4s Mitigated DUX4-Associated Muscle Toxicity In Vivo [0072] Adult wild-type male C57BL/6 mice were co-injected with 1) 3×10 9 DNase resistant particles (DRP) of AAV.CMV.DUX4.V5 or were sham injected, and 2) 3×10 10 DRP of AAV.miDUX4 or control AAV.CMV.GFP into the tibialis anterior muscle. Animals were sacrificed two weeks later. Muscles were cryopreserved and cut into 10 mm cryosections, then stained with hematoxylin and eosion (H&E). [0073] Animals that received DUX4 and eGFP vectors showed histological indicators of muscle damage. Specifically, these muscle sections contained abundant myofibers with centrally-located nuclei, small-bore myofibers (both of which indicate newly regenerated muscle), and deposition of fibrotic tissue. At 4 weeks, miDUX4-treated animals were indistinguishable from sham-injected normal wild-type muscles. [0074] MiDUX4-treatment significantly mitigated DUX4-induced muscle degeneration, compared to control GFP-injected muscles. Example 6 AAV6.miDUX4s Protected Muscles from Pathological Molecular Changes Associated with FSHD [0075] Caspase-3 is expressed in myofibers of FSHD patients and is activated by DUX4 expression in mouse muscle. The effect of expression of DUX4 in the presence and absence of AAV6.miDUX4 was examined. [0076] Eight-week-old C57BL/6 female mice received 50 μl direct intramuscular injections into the tibialis anterior. Premixed virus cocktails contained 8×10 8 DNAse resistant particles of AAV6.DUX4 and 3×10 10 of either AAV6.miDUX4 or AAV6.eGFP. Muscle samples were prepared as described in Example 5 and stained with cleaved Caspase-3 (Cell Signaling Technology, Danvers, Mass.) polyclonal antibodies by standard methods. [0077] Uninhibited DUX4 expression was associated with caspase-3 positive lesions in AAV6.DUX4-transduced control muscles in mice. In contrast, there were no caspase-3 positive myofibers in muscles coinjected with AAV6.DUX4 and AAV.miDUX4 vectors. Example 7 AAV6.miDUX4s Protect Mice from DUX4-Associated Grip Strength Deficits [0078] The effects of AAV6.miDUX4 on DUX4-associated hindlimb grip strength deficits in mice were measured. [0079] Grip strength was measured in forelimbs and hindlimbs of C57BL/6 mice (n=8 animals) one week before injection to establish a baseline, and then weekly up to 4 weeks postinjection as previously described in Wallace et al., Ann. Neural., 69: 540-552 (2011). By two weeks, mice injected with AAV6.DUX4 alone or AAV6.DUX4 with control AAV.eGFP showed significantly reduced grip strength compared to all other groups. This timepoint is consistent with the onset of degeneration in muscle cryosections. Weakness resolved in three weeks, as regenerative processes were underway. In contrast, animals coinjected with AAV6.DUX4 and AAV6.miDUX4 were not significantly weaker than saline-injected wild type mice at any timepoint following injection. Mice that received AAV6.miDUX4 alone were unaffected, indicating miDUX4 expression was well-tolerated by normal muscles. [0080] While the present invention has been described in terms of specific embodiments, it is understood that variations and modifications will occur to those skilled in the art. Accordingly, only such limitations as appear in the claims should be placed on the invention. [0081] All documents referred to in this application are hereby incorporated by reference in their entirety.

The present invention relates to RNA interference-based methods for inhibiting the expression of the DUX4 gene, a double homeobox gene on human chromosome 4q35. Recombinant adeno-associated viruses of the invention deliver DNAs encoding microRNAs that knock down the expression of DUX4. The methods have application in the treatment of muscular dystrophies such as facioscapulohumeral muscular dystrophy.

BACKGROUND OF THE INVENTION The present invention relates to a method for controlling the traffic within a network structure, said structure comprising a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved NodeB) or HNB (Home NodeB) and/or eNB (Evolved Node B) or NB (Node B), and a UE (User Equipment) that is associated with said H(e)NB and/or (e)NB. Further, the present invention relates to a network structure, preferably for carrying out the above method, said structure comprising a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved Node B) or HNB (Home NodeB) and/or eNB (Evolved Node B) or NB (Node B), and a UE (User Equipment) that is associated with said H(e)NB and/or (e)NB. DESCRIPTION OF THE RELATED ART In 3GPP there is ongoing, intensive search for architectural enhancements to efficiently support local IP connectivity. Currently such local IP connectivity is briefly denoted as LIPA (Local IP Access), in case the traffic is directed to a local network (e.g. a home network or an enterprise network) or as SIPTO (Selected IP Traffic Offload), in case the traffic is directed towards the Internet. The 3GPP efforts are directed both to home cell (i.e. H(e)NB) and the macro cell (i.e. (e)NB) scenarios, and for EPS (see for reference 3GPP TS 23.401 V8.6.0 (2009-06), “General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access”) and GPRS (see for reference 3GPP TS 23.060 V8.5.1 (2009-06), “General Packet Radio Service (GPRS); Service description”). 3GPP SA2 has started normative work already according to S2-094867, “New WID for Local IP Access & Internet Offload”. The present invention builds on assumptions and principles defined in these specifications and documents and related specifications, as will be explained in more detail below. IP connectivity for a UE towards an external (target) PDN (Packet Data Network) in the current state of the art of mobile network technology is provided by the PDN Gateway (P-GW) in the mobile network operator's core network. Mobility tunnels carry the traffic via the (e)NodeB and Serving-Gateway. Similarly, in GPRS scenarios IP connectivity is provided by the GGSN (Gateway GPRS Support Node) that corresponds to the PDN gateway in EPS scenarios. Further, in UTRAN radio access (3G) mobility tunnels carry the traffic via the NodeB, the RNC (Radio Network Controller) and the SGSN (Serving GPRS Support Node). The general problem is that the amount of plain (“dumb”) Internet traffic or traffic to local servers (e.g. in the home or enterprise network) is expected to grow considerably in the future. This type of traffic should not consume expensive resources in the mobile operator network, and consequently should be offloaded from his network as soon as possible. One possible location for IP traffic breakout is at the H(e)NB or (e)NB. Current state of the art has the concept of APN (Access Point Name), which allows separating traffic. The APN takes the form of a FQDN (Fully Qualified Domain Name) and is resolved ultimately to an IP address of the P-GW or GGSN that provides access to the respective PDN. In current discussions in standardization it is mostly assumed that for LIPA/SIPTO traffic a separate APN is used; requirements have also been stated that one common APN may be used for LIPA/SIPTO and non-LIPA/SIPTO type of traffic. No solution to achieve service continuity upon a handover of a UE to different H(e)NBs or (e)NBs has been given. Further, from TS Group Services and System Aspects; Local IP Access and Selected IP Traffic offload (Rel. 10), 3GPP TR 23.829 are obtainable further details with regard to LIPA and SIPTO. For several purposes, operators are interested in having full control of how traffic pertaining to a particular user and IP connection/flow should be routed: via the core network or directly via a local network in support of local network protocol access or selective network protocol traffic offload. SUMMARY OF THE INVENTION Thus, it is an object of the present invention to improve and further develop a method for controlling the traffic within a network structure and an according network structure in such a way, that a reliable and flexible control of traffic within the network structure is possible without the addition of remarkable complexity to the core network. In accordance with the invention, the aforementioned object is accomplished by a method according to claim 1 . According to this claim the method is characterized in that on the basis of a predefinable routing policy said DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via a local network in support of local network protocol access or selective network protocol traffic offload. Further, the aforementioned object is accomplished by a network structure. Such a network structure is characterized in that the DNS server is configured in a way that on the basis of a predefinable routing policy said DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via a local network in suppport of local network protocol access or selective network protocol traffic offload. According to the invention it has been recognized that the control of traffic within a network structure is possible in a very easy and reliable way by the DNS server. Further, it has been recognized that the controlling procedure can be based on predefinable routing policy which can be provided to the DNS server. Thus, traffic (e.g. IP flows) from a UE to a destination address and/or vice versa can be routed via the core network or directly via a local network (or a local traffic offload node nearby the Radio Access Network—RAN). The last mentioned routing procedures can be selected depending on the position of the destination address within a local network, which is associated to the HeNB or HNB or eNB or NB, or within the PDN. With such a control, operators will be able to flexibly and dynamically enable the routing via a local network (or a local traffic offload node nearby the RAN) for certain type of traffic and/or users (IP flows) in order to monitor traffic, to allow for traffic inspection for legal purposes, to optimize access to specific network services, e.g. to ensure a fast access, mobility and QoS (Quality of Service) and to add value to network services, e.g. block access to specific sites. Preferably, the PDN is the Internet, the network protocol is IP, the local network protocol access is LIPA (Local IP (Internet Protocol) Access) and the selected network protocol traffic offload is SIPTO (Selected IP Traffic Offload). In this case the operator will be able to flexibly and/or dynamically disable LIPA/SIPTO for certain type of traffic and/or users (IP flows) with regard to the above mentioned purposes. According to a preferred embodiment said DNS server could indicate—upon a DNS request by the UE—in a DNS response arouting information with regard to the traffic routing via the core network or via the local network (or a local traffic offload node nearby the Radio Access Network—RAN). In this way the controlling procedure can be started very easily by a DNS request of the UE. This DNS-based dynamic routing policy configuration/management can be done in a centralized fashion at the DNS server and thus eases the management and operation associated with controlling traffic either via the core network or via the local network (or a local traffic offload node nearby the Radio Access Network—RAN). With regard to a very flexible traffic routing a LP-GW (Local PDN Gateway—also known as L-GW or traffic offload function (TOF)) could be associated or collocated with the HeNB or HNB or eNB or NB. Preferably, a DNS proxy functionality could be implemented at the LP-GW. This functionality could intercept the DNS request and forward it to the operator DNS server. In response to the DNS request, the DNS server could send a DNS response with the destination address and preferably with additional information that indicates how the traffic should be handled. For providing the routing information in a very easy manner the routing information could be provided by a flag in the DNS response, that indicates to the HeNB or eNB or to a LP-GW the subsequent traffic routing. With regard to a very reliable traffic control and to supporting service continuity of the traffic a DNS proxy functionality could be implemented at the HeNB or eNB or at a LP-GW to provide a local DestNAT (Destination Network Address Translation) network protocol address to the UE as part of the DNS response and to establish the binding/association between the local DestNAT and the destination address within the local network or within the PDN. Preferably, the DNS server could request the LP-GW for a DestNAT address for the destination address within the local network or within the PDN, if there is no DNS proxy functionality at the LP-GW. In that case, the DNS server would provide the DestNAT directly to the requesting UE. According to a preferred embodiment the H(e)NB or (e)NB (HeNB or HNB or eNB or NB) or a LP-GW could have a Twice-NAT functionality for translating the addresses of both source and destination into two different addresses, a SrcNAT (Source Network Address Translation) address and DestNAT address, respectively. Further, a stateless Twice-NATing could be performed, if the DestNAT address includes the destination address within the local network or within the PDN. For instance, in case IPv6 is used between UE and LP-GW and the real IP address of the destination is an IPv4 address, the DestNAT can take for example a format similar to “2001:3001:2521:5323:FFFF:FFFF:FFFF:IPv4-address-of-destination”. Without the involvement of LP-GW or HeNB or eNB with DNS proxy functionality, the DNS server could directly provide the DestNAT address to the UE. Such a DestNAT address could be provided in the same format as mentioned within the last paragraph. Based on the above explained Twice-NATing service continuity for local IP access traffic or for a selected IP traffic offload, e.g. SIPTO, traffic could be achieved upon a handover of a UE to different H(e)NBs or (e)NBs. According to another preferred embodiment service continuity for a local IP access traffic or a selected IP traffic offload traffic upon a handover of a UE to a different H(e)NB or (e)NB could be achieved using simple tunnelling or source routing. Within a concrete embodiment the UE could support a tunnelling mechanism to the H(e)NB or (e)NB. Preferably, a network layer of the UE could maintain a per-connection or flow state to decide whether an IP flow/traffic should be tunnelled or not. Alternatively, the UE could support a source routing mechanism for maintaining the above mentioned service continuity. Within a further preferred embodiment, two addresses could be indicated in the DNS response, one address indicating the destination address within the local network or within the PDN and the other address used for tunnelling. Within an alternative approach two addresses could be indicated in the DNS response, the address of the LP-GW, routable within the PDN, and the destination address within the local network or within the PDN. The above mentioned embodiments refer to solutions for UEs supporting only single PDP (Packet Data Protocol) context/PDN connection. However, there could be scenarios with UEs supporting multiple PDP context/PDN connections. In this case, said DNS server could select and indicate—upon a DNS request by the UE—in a DNS response to the UE which APN to use for a particular traffic flow or connection. In this solution service continuity with regard to local network protocol access traffic or “selected network protocol traffic offload” traffic will be supported by the core network. According to a preferred embodiment at least one PDP context/PDN connection could be dedicated for LIPA and/or SIPTO. The DNS server can select the relevant PDP context/PDN connection. Preferably, the DNS server could have prior knowledge on available APNs or PDP context/PDN connections. Within a further preferred embodiment the UE could notify APNs currently available to UE in the prior DNS request. Thus, the DNS server could be actually informed about available APNs of PDP context/PDN connections. Preferably, the DNS server could base its APN selection on parameters or metrics that prioritize the available APN or APNs. Thus, the UE, which is capable to identify the recommended APN from the DNS response could accordingly route the traffic. According to a preferred embodiment the DNS server can also indicate—only by using a flag in the response—that the UE should use a pre-configured APN for a particular traffic flow or connection. According to a preferred embodiment the UE—due to an indication or flag in a DNS response—may not cache results of DNS requests for local network protocol access and/or selected network protocol traffic offload or may fully disable DNS caching for respective APNs. Within a further preferred embodiment the UE could be involved in the selection process of the DNS server. The invention presents a set of mechanisms that enable operators to control traffic handling of UEs and decide on how to route it, via a local network protocol access or a selected network protocol traffic offload, e.g. LIPA or SIPTO, or core network. The decision could depend on the domain name, kind or type of the destination address, kind or type of application. Technical effects on the implementations of LP-GWs at H(e)NBs/(e)NBs, DNS servers, and/or UEs are expected—depending on the particular embodiment. Within the present invention are given different solutions that enable an operator to dynamically control whether a traffic flow of a particular UE should be routed directly via a local network (or a local traffic offload node nearby the Radio Access Network—RAN) or via the core network. The invention is also related to service continuity of preferably LIPA/SIPTO traffic. In the discussion, there is considered LIPA/SIPTO at H(e)NB, but the same devised approaches can be easily applied to the case of MACRO SIPTO at (e)NBs. The invention enables operators to dynamically/flexibly control whether a particular traffic to/from a particular UE should be routed via LIPA/SIPTO or the operator core network. Further, there are considered solutions that support service continuity of LIPA/SIPTO traffic and those that do not, for the purpose of applying different charging schemes. Further, there are considered solutions that are completely transparent to UEs, so operators have full control. The above mentioned objects are achieved with minimal or no additional complexity to the core network. Modifications at the UEs are minimized and the solutions require no or only simple modifications at one single layer, application or network layer. There are several ways how to design and further develop the teaching of the present invention in an advantageous way. To this end it is to be referred to the patent claims and to the following explanation of preferred embodiments of the invention by way of example, illustrated by the figures on the other hand. In connection with the explanation of the preferred embodiments of the invention by the aid of the figures, generally preferred embodiments and further developments of the teaching will we explained. BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is a diagram schematically illustrating an overall network architecture, FIG. 2 is a diagram schematically illustrating a LIPA/SIPTO traffic handling by an operator DNS, FIG. 3 is a diagram schematically illustrating possible paths for downlink traffic after handoff to a new HeNB or eNB, FIG. 4 is a diagram schematically illustrating possible paths for uplink traffic after handoff to a new HeNB or eNB and FIG. 5 is a diagram schematically illustrating a direct communication between UE and DNS server. DETAILED DESCRIPTION OF THE INVENTION In the following description is considered the case of the Internet as a PDN. Thus, the network protocol will be IP, the local network protocol access will be LIPA, and the selected network protocol traffic offload will be SIPTO. However, the following description shall not be seen as limitation to the Internet case. The given solutions will also be valid for other PDNs. Insofar, also other PDNs are involved in an analogous consideration. The following embodiments are based on DNS routing policies. First, there are explained two solutions that are based on “Twice-NATing” and “simple tunnelling”, respectively. Both solutions consider the scenario where a UE has or supports only one single PDP context/PDN connection for LIPA/SIPTO and non-LIPA/SIPTO traffic (i.e. it shall be noted that these solutions can also support a UE supporting multiple PDP contexts/PDN connections). In another solution, there is considered the case where a UE has or supports multiple PDP contexts/PDN connections. In this solution, the operator explicitly indicates, via a DNS reply to a DNS query from a UE, to the UE which APN it should use for a particular traffic. For giving an overview, these three solutions are briefly summarized as follows: Solutions based on single PDP Context/PDN connection (applicable also to UEs supporting multiple APNs): DNS-based routing policies in operator DNS: Operator controls traffic handling based on DNS resolutions. Service continuity for LIPA traffic can be supported either with no additional complexity in core network (when the traffic tunnelled to the P-GW and then routed to the LP-GW based on normal IP routing) or with little additional complexity in the S-GW (when the traffic is directly routed to the LP-GW by the S-GW) through either: Twice-NATing:  DNS resolution gives the UE a Destination IP address (DestNAT) to which traffic in the operator network is routed to the LP-GW (based on configuration), which performs Twice-NAT. Here, traffic handling is transparent to UEs. Simple Tunnelling:  DNS resolution informs the requesting UE of the LP-GW address, which the UE can use for simple IP-in-IP tunnelling of those flows that it should send via LIPA/SIPTO. UE requires simple extra functionality, but could also be involved in the decision. Alternatively to simple tunnelling, source routing and routing header in IPv6 can be also used. Solution based on multiple PDP Contexts/PDN connections (DNS-based): Operator controls traffic handling based on DNS replies that indicate to a UE which APN to use for a particular IP flow/connection. UE requires minimal extra functionality, but could also be involved in decision process. Service continuity for LIPA/SIPTO traffic is supported in this solution. The following description is mainly directed to SIPTO at H(e)NB, but the same solutions can be applied to the case of SIPTO at macro (e)NBs. 1. Network Architecture FIG. 1 depicts the major components of the envisioned architecture, namely a SIPTO enabled domain or PDN, e.g. Internet, core DNS server, MME (Mobility Management Entity), (H)eNB (or alternatively (H)NB for 3G), UE, Core P/S-GWs (or alternatively GGSNs/SGSNs for GPRS), and a local gateway collocated with (H)eNB/(H)NB, called LP-GW. To simplify the description, the text and figures only refer to the EPS architecture (i.e. (H)eNB, S-GW, P-GW). The concepts apply equally to the GRPS architecture (i.e. (H)NB, RNC, SGSN, GGSN). The local gateways may also not be collocated with (H)eNB/(H)NBs. In this description, two types of UEs are considered: UEs using one single PDN connection (have one IP address) for both LIPA/SIPTO and non-LIPA/SIPTO traffic and UEs using multiple PDN connections (e.g., at least one dedicated for LIPA/SIPTO). The Local Gateway (LP-GW or L-GW or TOF) collocated with (H)eNB can be either a local P-GW with functionalities of P-GW (e.g., in case of UEs using multiple APNs) or a simple L-GW (i.e. only including the necessary P-GW functions). 2. LIPA/SIPTO Traffic Control In the envisioned mechanisms, decision on which traffic is to be handled via the macro network and which one to be offloaded via LIPA/SIPTO is taken by the operator via core DNS resolutions. FIG. 2 shows how DNS is involved in the SIPTO/LIPA traffic handling. We consider a scenario whereby a UE desires to connect to YouTube server while being at home (i.e., via HeNB with a local GW collocated). A DNS proxy is assumed to be at the Local GW. Initially, the UE issues a DNS request to the core DNS server requesting the IP address of the YouTube server. The local DNS proxy at the Local GW intercepts the DNS request and forwards it to the operator DNS server. In response to the DNS request, the Operator DNS server sends a DNS reply with the IP address of the peer (YouTube) along with additional information (e.g., Information 1 in FIG. 2 ) that indicates how the traffic should be handled. Following the DNS reply from the Core DNS, the local GW takes Action 1 in case the reply indicates LIPA/SIPTO traffic and sends a DNS reply with particular Information 2 . A simple “DNS-based LIPA/SIPTO control” solution, referred to as Simple Source NATing, works according to the steps of FIG. 2 with the following features: Information 1 : LIPA/SIPTO flag that indicates how the traffic should be handled (via LIPA/SIPTO or macro). Information 2 : Global IP address of peer (YouTube) Action 1 : Store at Local GW (or H(e)NB) the external IP address of the peer (YouTube) as this traffic should be subject to LIPA/SIPTO. Action 2 : Apply simple source NATing: Local GW adds an entry in its NAT table for translating the IP address of UE into an address of the local GW. It should be emphasized that whilst we involve a DNS proxy at the local GW in the DNS resolution, with the simple modifications described above the DNS resolution can be also performed in an E2E (End-to-End) fashion. 3. Support of Service Continuity for SIPTO Traffic FIGS. 3 and 4 depict all possible paths for both uplink and downlink traffic upon handoff or handover of a UE to a target (H)eNB. Initially, we consider the case of UEs using only one single APN. There are two possible paths for downlink traffic, namely 1 D and 2 D, and five possible paths for uplink traffic namely 1 U- 5 U. In case LIPA/SIPTO is handled via IP flow filters, which either are provided dynamically (via PCRF) or have been provided pro-actively (via HMS (HeNB Management System)) to the target (H)eNB, the uplink traffic can break-out at the target (H)eNB (i.e., path 1 U in FIG. 4 ). In the DNS-based LIPA/SIPTO control solution, the target (H)eNB has no information about the decision taken during the DNS resolution at the source (H)eNB and as a result, the uplink traffic will break-out at the P-GW (i.e., path 4 U in FIG. 4 ). As a result, service continuity cannot be supported, as the correspondent node (YouTube server) will see a different source IP address of the UE (i.e., UE's global operator IP address). This, of course, excludes the case of mobility-aware applications or if additional IP mobility solutions (e.g. Mobile IP) are used “on-top-of” the functionality provided by the mobile core. Service continuity for ongoing SIPTO/LIPA traffic can be supported only if the break-out point for ongoing connections remains the same (i.e. in the local GW of the source (H)eNB). This implies that a mechanism is needed to route the UL (Uplink) traffic from the UE to the anchor L-GW at (H)eNB and the DL (Downlink) traffic from the anchor L-GW at (H)eNB to the UE. This is possible when downlink and uplink traffic traverse paths 1 D or 2 D and 2 U, 3 U or 5 U, respectively. Path 3 U can be established with some additional implementation-level functions at L-GW (to be explained later) but with no additional complexity to P/S-GWs. In the uplink, path 2 U and 5 U are clearly more optimized than Path 3 U in terms of resource savings and E2E delay; it however requires some extra functionality at S-GW or eNB respectively that shall enable S-GW or eNB to distinguish SIPTO traffic from non-SIPTO traffic, break it out and route it to the source (H)eNB. In the downlink, path 2 D is also more optimal, but this either requires the establishment of a direct tunnel between Local GWs in the source and target (H)eNBs or support for data forwarding over the X2 interface between the source and target (H)eNBs. In the following, we define the mechanisms/methods required to enable service continuity for ongoing SIPTO/LIPA traffic. Twice-NATing Based SIPTO Service Continuity Support: In this solution, the SIPTO traffic handling follows steps of FIG. 2 with the following features: Information 1 : SIPTO flag that indicates how the traffic should be handled via SIPTO or macro network. Information 2 : Global IP address of peer in case of non-SIPTO traffic. Otherwise, a local IP address of the local GW—a destination NAT address—that is routable within the macro network and referred to as DestNAT. Action 1 : Allocate a local destination NAT address (DestNAT) and associate it with global IP address of the peer (YouTube). Action 2 : Perform Twice NAT: translate the DestNAT address to the global IP address of the peer (YouTube) and the UE's IP address (source IP) into the external NAT address (Source NATing). Using the DestNAT (which is assumed to be routable within the operator network towards the source (H)eNB in this solution) and Source NAT, service continuity of the SIPTO traffic can be guaranteed upon handoff of the UE to a target eNB by enforcing the downlink and uplink traffic to follow paths 1 D or 2 D and 2 U, 3 U or 5 U, as shown in FIGS. 3 and 4 , respectively. In the uplink, path 3 U can easily be established as this requires merely the Twice-NATing functionality in the L-GW, which needs to intercept packets sent to the DestNAT address and perform the Twice-NATing operation. Path 2 U and 5 U requires some extra functionality in the S-GW or eNB, respectively, to detect traffic targeted to the L-GW, based on the DestNAT address range, for those PDN connections that are potentially subject to SIPTO/LIPA, which is then broken out of the PDN connection and routed directly to the L-GW, based on the routable DestNAT address. In the downlink, path 1 D follows the normal/standardized path. The optimization of 2 D would rely on extra functionality in the L-GWs and/or source/target (H)eNBs to establish a direct tunnel between the L-GWs in the source and target (H)eNBs or support for data forwarding over the X2 interface between the source and target (H)eNBs. Since the DestNAT address of the Internet server is routable within the operator network, the (H)eNB, S-GW or P-GW is able to route the traffic to the LP-GW that anchors an ongoing connection. The tunnel between S-GW and LP-GW may be released immediately after the handover by the S-GW, or may be released either by the S-GW or the L-GW after a certain idle time, i.e. no traffic through the tunnel for some time. This shall have no impact on the E2E communication between UE and LP-GW: Routing of uplink traffic at S-GW is based on the IP address of LP-GW, i.e. DestNAT. Instead of having the DNS proxy in the eNB/LP-GW, the DNS resolution could also occur “End-to-End” between UE and DNS server. In this regard, the DNS server could directly provide the real/global IPv4 address as part of the DestNAT. For reference, see FIG. 5 . In this solution, address space for Destination NAT IP Addresses at LP-GW may be limited as DestNAT must be routable in complete operator network. This limitation can be overcome in case of IPv4 and IPv6 support or by using UE's source/destination port numbers in conjunction with the UE's IP address to perform the DestNAT. To avoid caching of DNS results for SIPTO traffic, the DNS response can include an adequate indication, e.g. SIPTO flag, based on which UEs do not cache results of DNS query, or may alternatively fully disable DNS caching for SIPTO capable APNs. Simple-Tunnelling Based SIPTO Service Continuity Support: In this solution, the SIPTO traffic handling follows steps of FIG. 2 with the following features: Information 1 : LIPA/SIPTO flag that indicates how the traffic should be handled via LIPA/SIPTO or macro network. Information 2 : Global IP address of peer (YouTube) in case of non-LIPA/SIPTO traffic. Otherwise, two addresses: the IP address of the local GW, routable within the macro network, and the global IP address of the peer (YouTube). Action 1 : Include the IP-in-IP tunnelling address of the local GW by means of a new DNS record. Action 2 : Simple source NATing, i.e. UE is the source. In this solution, from a DNS reply indicating two addresses (i.e., Information 2 ), the UE understands that this IP connection is subject to LIPA/SIPTO via the local GW and tunnels the uplink traffic to the local GW address using simple IP-in-IP tunnel. The Simple Tunnelling mechanisms could alternatively be achieved through Source Routing, e.g. based on the IPv6 Routing Header; in this case, the UE and Local GW would require the necessary functionality. The UE maintains per-connection/flow state to decide whether a flow should be tunnelled or not. This information can be kept at network-layer and can thus be completely transparent to the application layer. Upon reselection of a new (H)eNB, the UE flushes its DNS cache in order to get the new LP-GW address with the next DNS resolution. In this solution, since the IP address of the LP-GW or local GW (which is used for the simple tunneling) is routable within the operator network, service continuity of the SIPTO traffic can be supported. In this solution, which assumes that the IP address of the local GW is routable within the operator network towards the source (H)eNB, service continuity of the SIPTO/LIPA traffic can be guaranteed upon handoff of the UE to a target eNB by enforcing the downlink and uplink traffic to follow paths 1 D or 2 D, and 2 U, 3 U or 5 U, as in FIGS. 3 and 4 , respectively. In the uplink, path 3 U can easily be established as this requires merely the Simple Tunnelling functionality in the L-GW, which needs to terminate the tunnel and route the traffic towards the final destination in the local network or PDN. Path 2 U and 5 U require some extra functionality in the S-GW or eNB respectively to detect traffic targeted to the L-GW (based on the L-GW address range) for those PDN connections that are potentially subject to SIPTO/LIPA, which is then broken out of the PDN connection and routed directly to the L-GW. In the downlink, path 1 D follows the normal/standardized path (e.g. via the P-GW). The optimization of 2 D would rely on extra functionality in the L-GWs and/or source/target (H)eNBs to establish a direct tunnel between the L-GWs in the source and target (H)eNBs or support for data forwarding between the source and target (H)eNBs. LIPA/SIPTO SERVICE CONTINUITY SUPPORT FOR UEs USING MULTIPLE APNs (with at Least One Dedicated for LIPA/SIPTO): In this solution, UEs are assumed to have multiple established PDP contexts/PDN connections with different APNs, with at least one APN dedicated for LIPA/SIPTO. The Operator DNS indicates, preferably in an E2E fashion, to the UE which APN (see the options below) to use for a given flow upon receiving a DNS query from the UE. As a result, the UE accordingly uses the PDN connection assigned with the APN that was indicated by the operator in the DNS query. Service continuity for LIPA/SIPTO traffic is also supported as the standard mobility procedures ensure that the PDN connections are maintained during handover. The downlink and uplink traffic follow paths 1 D and 2 U as shown in FIGS. 3 and 4 , respectively. In this solution, the DNS server must be aware of the configured APNs. The UE may also inform the DNS server of active APNs (currently available to UE) as part of the DNS request. The DNS server may also recommend a list of APNs in order of priority that is defined based on different parameters/metrics. The DNS server may also simply set up a flag that indicates whether LIPA/SIPTO should be used. In this case, UE must be able to autonomously identify the adequate APN for LIPA/SIPTO based on operator configurable conventions. In response to the DNS reply, the UE binds the new IP flow/connection (socket) to the UE's IP address associated with the recommended PDN connection/APN. The UE requires simple network-level functionality for the binding process (independently from the application layer) of the new IP flow/connection with the recommended APN and could also be involved in the decision process. In the present description are proposed solutions for handling LIPA/SIPTO traffic control considering two types of UEs, namely UEs supporting only one single APN/PDN connection and UEs supporting multiple APNs (with simultaneous PDN connections) with at least one dedicated for LIPA/SIPTO. All solutions are based on the operator's core DNS and some support service continuity of LIPA/SIPTO traffic by enforcing both downlink and uplink traffic to traverse the Local GW at the (H)eNB, which anchors the IP flow/connection. Many modifications and other embodiments of the invention set forth herein will come to mind the one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

A reliable and flexible method for controlling traffic within a network structure without the addition of remarkable complexity to the core network is provided, the structure including a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved Node B) or HNB (Home Node B) and/or eNB (Evolved Node B) or NB (Node B) and a UE (User Equipment) that is associated with the HeNB or HNB and/or eNB or NB. On the basis of a predefinable routing policy the DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via the local network in support of local network protocol access or selected network protocol traffic offload.

BACKGROUND OF THE INVENTION This nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2003-393340 filed in Japan on Nov. 25, 2003, the entire contents of which are hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates to a power supply circuit for supplying power by boosting an input voltage of a DC power source, and in particular, to a power supply circuit for repeating start/stop voltage boosting operations according to PWM (Pulse Width Modulation) signals. Description of the Prior Art An electronic apparatus such as a portable telephone, a PDA (Persona Digital Assistant), or a digital camera is equipped with a liquid crystal display (LCD). In recent years, a white light-emitting diode has been increasingly used as one of light sources (back light or front light) for the LCD due to its superior properties in durability, light-emitting efficiency, and space required thereby. The white light-emitting diode requires a relatively high forward voltage to operate. Used as a light source are a plurality of white light-emitting diodes which are connected in series so as to make brightness of individual diodes evenly. A voltage higher than a voltage supplied from a battery built in a mobile apparatus is required to drive these white light-emitting diodes. Conventionally, a power supply circuit of voltage boosting type shown in FIG. 9 has been used as a circuit for driving the white light-emitting diodes. FIG. 9 is a block circuit diagram showing an electronic configuration of a conventional power supply circuit. The power supply circuit shown in FIG. 9 comprises a DC power source 1 such as a lithium-ion battery, an input capacitor 2 , a coil 3 , a diode 4 , an output capacitor 5 , a resistor (output current detection resistor) R 1 , and a boost chopper regulator 10 that performs voltage boosting operation by switching between operations for accumulating and discharging energy in and from the coil 3 . The boost chopper regulator 10 is integrated into an IC package. Six white light-emitting diodes (load) LED 1 to LED 6 , as a light source for an LCD, are driven by this power supply circuit. A negative terminal of the DC power source 1 is connected to ground. A positive terminal thereof is connected to one end of the input capacitor 2 and to one end of the coil 3 as well. Other end of the input capacitor 2 is connected to ground. Other end of the coil 3 is connected to an anode of the diode 4 , and a cathode of the diode 4 is connected to ground through the output capacitor 5 . A series circuit consisting of the white light-emitting diodes LED 1 to LED 6 and the resistor R 1 is connected in parallel to the output capacitor 5 . The voltage boost chopper regulator 10 is provided with a power supply terminal Vi as a terminal for external connection, a ground terminal GND, an output voltage monitoring terminal Vo, a feedback terminal FB, and a control terminal CTRL. The power supply terminal Vi is connected to the positive terminal of the DC power source, and the ground terminal GND is connected to ground. With this configuration, the voltage boost chopper regulator 10 is fed with power from the DC power source 1 as driving power. Furthermore, a switching terminal Vsw is connected to a node between the coil 3 and the diode 4 . The output voltage monitoring terminal Vo is connected to the cathode of the diode 4 . The feedback terminal FB is connected to a node between the white light-emitting diode LED 6 and the resistor R 1 . Fed to the control terminal CTRL is, as will be described later, a brightness control signal (external input signal) for adjusting brightness of the white light-emitting diodes LED 1 to LED 6 . Next, an internal configuration of the voltage boost chopper regulator 10 and connections therein will be described. The voltage boost chopper regulator 10 comprises N-channel FETs (switching elements) 11 and 12 , a drive circuit 13 , a current detection comparator 14 , an oscillation circuit 15 , an amplifier 16 , a PWM comparator 17 , an error amplifier 18 , a reference power source 19 , resistors R 2 , R 3 , and R 4 , a soft-start circuit 20 , a start/stop circuit 21 , an overheating protection circuit 22 , and an overvoltage protection circuit 23 . Drains of the FETs 11 and 12 are connected to the switching terminal Vsw together, and gates thereof are connected to the drive circuit 13 together. A source of the FET 12 is connected to ground, and a source of the FET 11 is connected to ground through the resistor R 2 . Both ends of the resistor R 2 are connected to two input terminals of the current detection comparator 14 respectively. An output from the current detection comparator 14 and one of two outputs from the oscillation circuit 15 are added together by the amplifier 16 and fed to one input terminal of the PWM comparator 17 . In addition, an output from the PWM comparator 17 and other of two outputs from the oscillation circuit 15 are fed to the drive circuit 13 respectively. An output from the error amplifier 18 is fed to other input terminal of the PWM comparator 17 . One input terminal of the error amplifier 18 is connected to the feedback terminal FB. Other input terminal of the error amplifier 18 is connected to one respective end of the resistors R 3 and R 4 . Other end of the resistor R 4 is grounded, and other end of the resistor R 3 is connected to a positive terminal of the reference power source 19 . A negative terminal of the reference power source 19 is connected to ground. Each respective output from the soft-start circuit 20 , the start/stop circuit 21 , the overheating protection circuit 22 , and the overvoltage protection circuit 23 is fed to the drive circuit 13 . A brightness control signal is fed to the soft-start circuit 20 and the start/stop circuit 21 through the control terminal CTRL. An output voltage Vout is fed to the overvoltage protection circuit 23 through the output voltage monitoring terminal Vo. Next, how the power supply circuit configured in this way operates will be described. Across the output capacitor 5 , the power supply circuit shown in FIG. 9 produces the output voltage Vout which is boosted from the input voltage Vin supplied from the DC power source 1 as a result of the FET 12 being turned on and off by the drive circuit 13 . To be more specific, when the FET 12 is turned on by receiving a predetermined gate voltage at the gate thereof from the drive circuit 13 , current flows through the coil 3 from the DC power source 1 and, thereby the coil 3 accumulates energy therein. When the FET 13 is turned off by not receiving the predetermined gate voltage at the gate thereof, the accumulated energy in the coil 3 is released, thereby causing a back electromotive force in the coil 3 . The back electromotive force produced in the coil 3 is superimposed on the input voltage Vin supplied from the DC power source 1 , and the resulting voltage charges the output capacitor 5 through the diode 4 . A repetition of these operations will cause voltage boosting operation, which eventually causes the output voltage Vout to be produced across the output capacitor 5 . By this output voltage Vout, the output current lout flows through the white light-emitting diodes LED 1 to LED 6 so that the white light-emitting diodes LED 1 to LED 6 emit light. A feedback voltage Vfb obtained by multiplying a value of the output current lout by a resistance value of the resistor R 1 , is fed to the one input terminal of the error amplifier 18 through the feedback terminal FB. Then, the feedback voltage Vfb is compared with a reference voltage Vref that is supplied to the other input terminal of the error amplifier 18 . Here, the reference voltage Vref is such a voltage obtained by dividing the voltage of the reference power source 19 by the resistors R 3 and R 4 . Because of this arrangement, a voltage appearing at the output of the error amplifier 18 represents a difference between the feedback voltage Vfb and the reference voltage Vref, and is, then, fed to the one input terminal of the PWM comparator 17 . Fed to the other input terminal of the PWM comparator 17 is a signal resulted from adding and amplifying two signals by the amplifier 16 ; one signal being proportional to current flowing through the resistor R 2 when the FET 11 is turned on; and other signal being a sawtooth waveform signal fed from the oscillation circuit 15 . The resultant signal is compared with a level of the output voltage fed from the error amplifier 18 . Depending on the comparison result, during a period in which the level of the output voltage fed from the error amplifier 18 is higher than the level of the signal fed from the amplifier 16 , a PWM output of the PWM comparator 17 becomes “H” (High) level. During a period in which the level of the output voltage fed from the error amplifier 18 is lower than the level of the signal fed from the amplifier 16 , the PWM output of the PWM comparator 17 becomes “L” (Low) level. The drive circuit 13 , by receiving the PWM output from the PWM comparator 17 , turns on and off the FETs 11 and 12 according to a duty cycle of the PWM output. In other words, the drive circuit 13 feeds a predetermined gate voltage to the FETs 11 and 12 to turn them on at start timing of each cycle of a clock signal fed from the oscillation circuit 15 when the PWM output from the PWM comparator 17 is at “H” level. Thereafter, when the PWM output from the PWM comparator becomes “L” level, the drive circuit 13 stops feeding the gate voltage to the FETs 11 and 12 , thereby to turn them off. When the FETs 11 and 12 are controlled on and off in this way, a voltage boosting operation is performed so that the feedback voltage Vfb becomes equal to the reference voltage Vref. In other words, the output current lout will be stabilized at a level equal to a current value obtained by dividing the reference voltage Vref (this being equal to the feedback voltage Vfb) by the resistance value of the resistor R 1 . In addition, because the signal being compared by the PWM comparator 17 includes a signal based on current flowing through the resistor R 2 , i.e., a signal based on current flowing in the coil 3 when the FETs 11 and 12 are turned on, a peak current allowed to flow in the coil 3 can also be limited. Furthermore, by detecting that the output voltage Vout exceeds a predetermined overvoltage protection voltage, the overvoltage protection circuit 23 stops the operation of the drive circuit 13 . This function prevents an overvoltage exceeding the predetermined overvoltage protection voltage from being applied to the white light-emitting diodes LED 1 to LED 6 and the output capacitor 5 . The overheating protection circuit 22 , by detecting overheating caused by the operation of the drive circuit 13 and, in particularly, overheating of and around the FET 12 , stops the operation of the drive circuit 13 . This function protects the voltage boost chopper regulator 10 against failure and breakdown caused by overheating. The start/stop circuit 21 , in accordance with the external input signal fed to the control terminal CTRL, instructs the drive circuit 13 so as to start and stop the driving operations of the FETs 11 and 12 . Therefore, it is possible to adjust the brightness of the white light-emitting diodes LED 1 to LED 6 by feeding, as an external input signal, a brightness control signal in the form of PWM signal. To be more specific, when the brightness control signal fed to the control terminal CTRL is at “H” level, the start/stop circuit 21 instructs the drive circuit 13 to start the driving operation of the FETs 11 and 12 so as to allow the output current Iout to flow through the white light-emitting diodes LED 1 to LED 6 . When the brightness control signal is at “L” level, the start/stop circuit 21 instructs the drive circuit 13 to stop the driving operation of the FETs 11 and 12 so as to allow the output voltage Vout to drop. As a result, an average current flowing through the white light-emitting diodes LED 1 to LED 6 changes according to the duty cycle of the brightness control signal. Because the brightness of the white light-emitting diodes LED 1 to LED 6 is proportional to this average current, the brightness thereof is adjusted in the manner described above. The soft-start circuit 20 , by instructing the drive circuit 13 to change the output duty cycle gradually at startup, is to increase the output voltage Vout gradually. Unless the output voltage Vout is increased gradually, an excessive amount of charging current flows from the DC power source 1 if the output capacitor 5 has not been charged. When this happens and if the DC power source 1 is a battery such as a lithium-ion battery, a burden is placed on the battery. Moreover, it is possible that the battery voltage drops due to the excessive amount of charging current, causing a problem in which the battery can not be fully used until the battery voltage reaches a discharge end voltage thereof. FIGS. 10 and 11 are waveform diagrams each showing voltage waveforms and a current waveform at specific portions of the power supply circuit shown in FIG. 9 . FIG. 10 shows waveforms when the soft-start circuit 20 is not operating, and FIG. 11 shows waveforms when the soft-start circuit 20 is operating. In FIGS. 10 and 11 , a symbol W 1 represents a voltage waveform of the brightness control signal to be fed to the control terminal CTRL. A symbol W 2 represents a voltage waveform of the output voltage Vout. A symbol W 3 represents a current waveform of the input current Iin. In FIGS. 10 and 11 , time t 0 indicating a time when the brightness control signal turns from “L” to “H” for the first time after startup, represents the startup timing of the power supply circuit shown in FIG. 9 . At time t 0 , the input voltage Vin is supplied from the DC power source 1 . Until time t 0 , the output voltage Vout has been 0V, and the output capacitor 5 has not been charged at all. First, the voltage boosting operation when the soft-start circuit 20 is not operating will be described with reference to FIG. 10 . In FIG. 10 , at startup (time t 0 ), i.e., when the brightness control signal turns from “L” level to “H” level for the first time (waveform W 1 ), the drive circuit 13 starts the voltage boosting operation. Since the soft-start function is not operating, the output voltage Vout rises to a voltage V 1 immediately (waveform W 2 ). At this moment, because the input current Iin serves as a current for charging the output capacitor 5 at the voltage V 1 , an amount of the current becomes excessively high (waveform W 3 ). Here it is to be noted that the boosted output voltage Vout allows the output current Io to flow through the white light-emitting diodes LED 1 to LED 6 and the resistor R 1 , and causes the feedback voltage Vfb to be generated. The output voltage Vout, when the feedback voltage Vfb is so regulated as to be equal to the reference voltage Vref, is referred to as the voltage Vi. Then, as the output capacitor 5 is charged, a level of the input current Iin decreases and becomes constant at time t 1 (waveform W 3 ). Next, at time t 2 , when the brightness control signal turns to “L” level (waveform W 1 ), the start/stop circuit 21 stops the voltage boosting operation of the drive circuit 13 . Then, the output voltage Vout becomes equal to the input voltage Vin of the DC power source 1 (waveform W 2 ), and the input current Iin stops flowing (waveform W 3 ). Then, at time t 2 and thereafter, when the brightness control signal is switched between “H” and “L” levels according to a predetermined duty cycle (waveform W 1 ), the output voltage Vout is switched between the voltages V 1 and the input voltage Vin in accordance with the brightness control signal (waveform W 2 ). The input current Iin that flows when the output voltage Vout is switched from the input voltage Vin to the voltage V 1 will be such a charging current for charging the output capacitor 5 with a voltage equivalent to a difference between the voltage V 1 and the input voltage Vin, because the output capacitor C 5 has been charged to the level of the input voltage Vin. Therefore, the input current Iin does not become an excessive current (waveform W 3 ). Described above is the voltage boosting operation when the soft-start circuit 20 is not operating. As explained, the problem is that the input current Iin becomes excessive at startup (time to). As a result, because an excessive current for charging the output capacitor 5 flows out from the DC power source 1 which is a battery in this example, a heavy burden is imposed on the battery. At the same time, the battery voltage drops because of this excessive amount of charging current, preventing the battery from being used until the battery voltage reaches its original discharge end voltage. The soft-start circuit 20 is provided to solve this problem. Next, the voltage boosting operation when the soft-start circuit 20 is operating will be described with reference to FIG. 11 . In FIG. 11 , at startup (time to), i.e., when the brightness control signal turns from “L” level to “H” level for the first time (waveform W 1 ), the drive circuit 13 starts the voltage boosting operation. Simultaneously, the soft-start circuit 20 changes the output duty cycle of the drive circuit 13 gradually. Once the output voltage Vout reaches the level of the input voltage Vin, the output voltage Vout rises to the voltage V 1 gradually (waveform W 2 ). At this moment, because the input current Iin serves as a current for charging the output capacitor 5 at the voltage Vin, the input current Iin does not become an excessive current (waveform W 3 ). After that, as the charging of the output capacitor 5 progresses, the level of the input current Iin decreases and becomes constant at time t 1 (waveform W 3 ). Next, at time t 2 , when the brightness control signal turns to “L” level (waveform W 1 ), the start/stop circuit 21 stops the voltage boosting operation of the drive circuit 13 . Then, the output voltage Vout becomes equal to the input voltage Vin of the DC power source 1 (waveform W 2 ), and the input current Iin stops flowing (waveform W 3 ). Then, at time t 2 and thereafter, the brightness control signal is switched between “H” and “L” levels according to a predetermined duty cycle (waveform W 1 ). When the brightness control signal is switched from “L” level to “H” level, the soft-start circuit 20 controls the switching operation of the drive circuit 13 so that the output voltage Vout rises to the voltage V 1 gradually. When the brightness control signal is switched from “H” level to “L” level, the output voltage Vout becomes equal to the voltage V 1 instantaneously (waveform W 2 ). The input current Iin that flows when the output voltage Vout rises from the input voltage Vin to the voltage V 1 will be such a charging current for charging the output capacitor 5 with a voltage equivalent to an increased amount of voltage, because the output capacitor 5 has been already charged to a voltage equivalent to the input voltage Vin. Therefore, the input current Iin does not become an excessive current (waveform W 3 ). In this way, when the soft-start circuit 20 functions, it is possible to prevent the input current Iin from increasing excessively and prevent, thereby, the DC power source 1 from being damaged. A similar technology utilizing a soft-start circuit is disclosed in Japanese Patent Application Laid-Open No. H11-069793. According to the disclosure, when a capacitor for a soft start is charged at startup, a soft-start control signal corresponding to the charged voltage is fed out. A switching power unit, based on the soft-start control signal, controls a switching element so as to increase a duty cycle gradually. As a result of this, it is possible to protect the switching element from damage. Furthermore, Japanese Patent Application Laid-Open No. 2000-324807 discloses a boost chopper switching regulator incorporating input and output cutoff switches. In this regulator, a switch for limiting current and a switch for preventing current from flowing for a certain period of time are used as the input and output cutoff switches. Because of this arrangement, it is possible to turn on the input and output cutoff switches, when the regulator starts a boosting operation, so as to prevent inrush current from flowing to an output capacitor from an input power source. According to the conventional power supply circuit shown in FIG. 9 , since the soft-start circuit 20 comes into operation every time the brightness control signal rises to “H” level so as to increase the output voltage Vout gradually, the output voltage Vout is unable to rise to the voltage V 1 instantaneously. For this reason, it is not possible to feed a constant output current Io through the white light-emitting diodes LED 1 to LED 6 , and it is thereby difficult to perform a desired brightness control in accordance with a duty cycle of the brightness control signal. According to the conventional technology described in Japanese Patent Application Laid-Open No. H11-069793, it is possible to prevent the switching element from being damaged even when the switching power unit is started up again. However, when the switching power unit is repeatedly turned on and off at short intervals, an output voltage rises slowly every time it is turned on due to the soft-start operation and does not reach a desired voltage. Therefore, it becomes difficult to perform a desired brightness control based on the duty cycle of the brightness control signal. Furthermore, according to the conventional technology described in Japanese Patent Application Laid-Open No. 2000-324807, since a combination of the switches that can limit current and the switches that can prevent current from flowing for a certain period of time is used, the circuit becomes complicated, and it becomes difficult to control the output voltage according to the duty cycle of the brightness control signal. SUMMARY OF THE INVENTION The present invention, in light of above-mentioned drawbacks, provides a power supply circuit capable of limiting excessive current flowing at startup and bringing an output voltage to a desired voltage instantaneously even when voltage boosting operations are repeated on and off according to PWM signals. The present invention provides a voltage booster type switching power supply circuit for boosting an input voltage supplied from a DC power source by means of PWM (Pulse Width Modulation) method so as to supply a predetermined output voltage to a load. The voltage booster type switching power supply circuit comprises a coil having one end thereof connected to one end of the DC power source, a rectifying element connected between other end of the coil and one end of the load, an output current detection resistor for detecting current flowing through the load, an output capacitor, connected between a node at which the rectifying element and the load are connected together and ground, for producing the output voltage across both ends thereof by being electrically charged, a switching element connected between the other end of the coil and ground, a drive circuit for stabilizing the output voltage by controlling the switching element by means of PWM method in accordance with a voltage appearing across the output current detection resistor, a start/stop circuit for regulating an amount of the output current by starting and stopping the drive circuit according to an external input signal fed externally thereto, and a soft-start circuit for controlling the drive circuit so as to increase the output voltage gradually by becoming operative when the external input signal becomes active for the first time after startup, and controlling the drive circuit so as to increase the output voltage promptly by becoming inoperative when the external input signal becomes active for the second time and thereafter after startup. By this arrangement, it is possible for the soft-start circuit to become operative by detecting a low output voltage at startup and, thereby prevent a current flowing from the DC power source from becoming excessive. Once the output voltage has risen, by inactivating the soft-start circuit, it is possible to stabilize the output voltage instantaneously and supply a stabilized load current even when the drive circuit is repeatedly controlled on and off according to the external input signal. According to another aspect of the invention, the voltage booster type switching power supply circuit activates the soft-start circuit only during the first rising period of the external input signal following startup. To perform this operation, there is provided the output voltage detection circuit for feeding out a comparison result signal by comparing the output voltage with a predetermined voltage, a feedback voltage detection circuit for feeding out a comparison result signal by comparing a voltage appearing across the output current detection resistor with a predetermined voltage, or the input voltage detection circuit for feeding out a comparison result signal by comparing the input voltage with a predetermined voltage. By this arrangement, it becomes possible, with a simplified circuit, to compare the output voltage, the voltage appearing across the output current detection resistor, or the input voltage with a predetermined voltage and, based on the comparison result, operate the soft-start circuit securely only during the first rising period of the external input signal. DESCRIPTION OF THE DRAWINGS This and other features of the present invention will become clear from the following description, taken in conjunction with the preferred embodiments with reference to the accompanying drawings in which: FIG. 1 is a circuit block diagram showing an electronic configuration of a power supply circuit of a first embodiment of the invention; FIG. 2 is a circuit diagram showing an electronic configuration of an output voltage detection circuit shown in FIG. 1 ; FIG. 3 is a waveform diagram showing voltage waveforms and a current waveform at different portions of the power supply circuit shown in FIG. 1 ; FIG. 4 is a circuit diagram showing another electronic configuration of the output voltage detection circuit shown in FIG. 1 ; FIG. 5 is a circuit block diagram showing an electronic configuration of a power supply circuit of a second embodiment of the invention; FIG. 6 is a circuit block diagram showing an electronic configuration of a power supply circuit of a third embodiment of the invention; FIG. 7 is a diagram for describing an overvoltage protection circuit shown in FIG. 6 ; FIG. 8 is a circuit block diagram showing an electronic configuration of a power supply circuit of a fourth embodiment of the invention; FIG. 9 is a circuit block diagram showing an electronic configuration of a conventional power supply circuit; FIG. 10 is a waveform diagram showing voltage waveforms and a current waveform at different portions of the power supply circuit shown in FIG. 9 ; and FIG. 11 is a waveform diagram showing voltage waveforms and a current waveform in another state at different portions of the power supply circuit shown in FIG. 9 . DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit block diagram showing an electronic configuration of a power supply circuit of a first embodiment of the invention. In FIG. 1 , such components as are found also in FIG. 9 are identified with the same reference numerals and descriptions thereof will not be repeated. The power supply circuit shown in FIG. 1 is different from the power supply circuit shown in FIG. 9 and is additionally provided with an output voltage detection circuit 24 in the boost chopper regulator 10 . The output voltage detection circuit 24 is connected between the output voltage monitoring terminal Vo and the soft-start circuit 20 so as to compare the output voltage Vout fed through the output voltage monitoring terminal Vo with a set voltage Vset. A comparison result signal obtained thereby is then fed to the soft-start circuit 20 . The output voltage detection circuit 24 described above can be configured by using, for example, a circuit shown in FIG. 2 . FIG. 2 is a circuit diagram showing an electronic configuration of the output voltage detection circuit 24 shown in FIG. 1 . The output voltage detection circuit 24 shown in FIG. 2 is comprised of a comparator 25 , a reference power source 26 , and resistors R 5 and R 6 . A set voltage Vset, obtained by dividing a voltage of the reference power source 26 by the resistors R 5 and R 6 , is fed to one input terminal of the comparator 25 . The output voltage Vout is fed to other input terminal of the comparator 25 through the output voltage monitoring terminal Vo. An output from the comparator 25 is fed to the soft-start circuit 20 . The output voltage detection circuit 24 , configured in this way, compares the output voltage Vout with the set voltage Vset and feeds a comparison result signal to the soft-start circuit 24 . For example, when the output voltage Vout is greater than the set voltage Vset, the comparison result signal turns to “H” level. When the output voltage Vout is smaller than the set voltage Vset, the comparison result signal turns to “L” level. The soft-start circuit 20 is switched between an operative state and an inoperative state according to the state of the comparison result signal fed from the output voltage detection circuit 24 and determined on the rising edge of the brightness control signal. To be more specific, when the comparison result signal is at “H” level on the rising edge of the brightness control signal, then the soft-start circuit 20 turns to the inoperative state. When the comparison result signal is at “L” level on the rising edge of the brightness control signal, then the soft-start circuit 20 turns to the operative state to thereby control the drive circuit 13 so as to perform a soft start. Hereinafter, operations of the power supply circuit shown in FIG. 1 will be described with reference to FIG. 3 . FIG. 3 is a waveform diagram showing voltage waveforms and a current waveform at different portions of the power supply circuit shown in FIG. 1 . In FIG. 3 , alphanumeric references W 1 , W 2 , and W 3 indicate a voltage waveform of the brightness control signal fed to the control terminal CTRL, a voltage waveform of the output voltage Vout, and a current waveform of the input current Iin respectively. Time t 0 , indicating the time when the brightness control signal turns from “L” to “H” for the first time, represents the startup timing of the power supply circuit shown in FIG. 1 . Then, at time to, the input voltage Vin is supplied from the DC power source 1 . Until time t 0 , the output voltage Vout has been 0 V, and the output capacitor 5 has not been charged at all. In FIG. 3 , at startup (time to), i.e., when the brightness control signal rises from “L” level to “H” level for the first time (waveform W 1 ), the output voltage Vout is smaller than the set voltage Vset because the output capacitor C 5 has not been charged. Therefore, the output from the output voltage detection circuit 24 is at “L” level. Then, the soft-start circuit 20 starts its operation by confirming that the output from the output voltage detection circuit 24 is at “L” level at this moment. Simultaneously, the drive circuit 13 starts the voltage boosting operation. In parallel with this operation, the soft-start circuit 20 controls the drive circuit 13 so that the output duty cycle therefrom changes gradually. Once the output voltage Vout reaches the level of the input voltage Vin, the output voltage Vout starts climbing to the voltage V 1 gradually (waveform W 2 ). Since the input current Iin at startup serves as a charging current for charging the output capacitor 5 at the input voltage Vin, the amount of current will not become excessive (waveform W 3 ). After that, as the charging of the output capacitor 5 progresses, the level of the input current Iin decreases and becomes constant at time t 1 (waveform W 3 ). Next, at time t 2 , when the brightness control signal turns to “L” level (waveform W 1 ), the start/stop circuit 21 stops the voltage boosting operation of the drive circuit 13 . Then, the output voltage Vout becomes equal to the input voltage Vin of the DC power source 1 (waveform W 2 ), and the input current Iin stops flowing (waveform W 3 ). Then, at time t 2 and thereafter, the brightness control signal is switched between “H” and “L” levels according to a predetermined duty cycle (waveform W 1 ). The soft-start circuit 20 turns to the inoperative state by confirming on the rising edge of the brightness control signal that the output from the output voltage detection circuit 24 is at “H” level. This is because the output capacitor C 5 has been already charged to the level of the input voltage Vin, the output voltage Vout is equal to the level of the input voltage Vin and greater than the set voltage Vset. As a result, the output voltage Vout switches between the voltage V 1 and the input voltage Vin instantaneously according to the brightness control signal (waveform W 2 ). The input current Iin that flows when the output voltage Vout is switched from the input voltage Vin to the voltage V 1 will be such a charging current for charging the output capacitor 5 with a voltage equivalent to a difference between the voltage V 1 and the input voltage Vin, because the output capacitor C 5 has been already charged to the level of the input voltage Vin. Therefore, the input current Iin does not become an excessive current (waveform W 3 ). In this way, at startup, the output voltage Vout is increased gradually by the soft-start circuit 20 so as to prevent the input current Iin from increasing excessively. Thereafter, when the voltage boosting operation is repeatedly turned on and off in accordance with the brightness control signal, it is possible to raise the output voltage Vout to a desired voltage instantaneously. By this function, it is possible to realize a power supply circuit capable of regulating the brightness to a desired level according to the brightness control signal fed thereto externally. FIG. 4 is a circuit diagram showing another electronic configuration of the output voltage detection circuit 24 shown in FIG. 1 . In FIG. 4 , such components as are found also in FIG. 1 are identified with the same reference numerals and descriptions thereof will not be repeated. The output voltage detection circuit 24 shown in FIG. 4 is different from the output voltage detection circuit 24 shown in FIG. 2 and is provided, instead of the comparator 25 , with a comparator 27 having a hysteresis characteristic. Fed to one input terminal of the comparator 27 is a set voltage Vset obtained by dividing the voltage of the reference power source 26 with resistors R 5 and R 6 . This set voltage Vset displays a hysteresis characteristic depending on an output from the comparator 27 . For example, when the output from the comparator 27 is at “L” level, then the set voltage Vset is 4.2 V, and, when the output from the comparator 27 is at “H” level, then the set voltage Vset is 3.0 V. Described below with reference to FIG. 3 is how the power supply circuit shown in FIG. 1 will operate when the aforementioned output voltage detection circuit 24 is used. The soft-start circuit 20 turns to the operative state and performs the soft-start operation when the output from the output voltage detection circuit 24 is at “L” level on the rising edge of the brightness control signal, and turns to the inoperative state and does not perform the soft-start operation when the output from the output voltage detection circuit 24 is at “H” level on the rising edge of the brightness control signal. In FIG. 3 , at startup (time t 0 ), i.e., when the brightness control signal rises from “L” level to “H” level for the first time (waveform W 1 ), the output from the output voltage detection circuit 24 is checked by the soft-start circuit 20 . At this moment, the output voltage Vout is smaller than 4.2 V because the output capacitor C 5 has not been charged. As a result, the output from the output voltage detection circuit 24 is at “L” level by which the soft-start circuit 20 is switched to the operative state. Consequently, at this timing, the drive circuit 13 starts the voltage boosting operation. Simultaneously, the soft-start circuit 20 is activated to change the output duty cycle of the drive circuit 13 gradually. Once the output voltage Vout reaches the input voltage Vin, it will rise gradually to the voltage V 1 (waveform W 2 ). However, the input current Iin flowing during this period, i.e., time t 0 to time t 1 , is not an excessive current, because the output capacitor 5 has been already charged to 4.2 V and the input current Iin serves as a current to charge the output capacitor 5 with a voltage portion exceeding 4.2 V. At the same time, while the output voltage Vout is rising, the output voltage Vout goes beyond the set voltage Vset of 4.2 V, thereby causing the comparator 27 to output “H” level and the set voltage Vset to change to 3.0 V. Next, at time t 2 , when the brightness control signal is turned to “L” level (waveform W 1 ), the start/stop circuit 21 stops the voltage boosting operation of the drive circuit 13 . Then, the output voltage Vout becomes equal to the input voltage Vin of the DC power source 1 (waveform W 2 ), and the input current Iin stops flowing (waveform W 3 ). Then, at time t 2 and thereafter, the brightness control signal is switched between “H” and “L” levels according to a predetermined duty cycle (waveform W 1 ). At time t 3 , the second rise of the brightness control signal, the output capacitor has been already charged to the input voltage Vin. Therefore, the output Vout is equal to or higher than the input voltage Vin and greater than 3.0 V. Accordingly, the output from the output voltage detection circuit 24 is kept at “H” level and thereby, the soft-start circuit 20 is in the inoperative state. Because the soft-start circuit 20 is inoperative at time t 3 , the output voltage Vout switches from the input voltage Vin to the voltage V 1 instantaneously according to the brightness control signal (waveform W 2 ). The input current Iin flowing when the output voltage Vout switches from the input voltage Vin to the voltage V 1 does not become excessive, because the output capacitor 5 has been already charged to the input voltage Vin and the input current Iin serves as a current to charge the output capacitor 5 with a voltage equivalent to a difference between the voltage V 1 and the input voltage Vin (waveform W 3 ). In this way, at startup, the output voltage Vout is increased gradually by the soft-start circuit 20 so as to prevent the input current Iin from becoming excessive. Thereafter, when the voltage boosting operation is repeatedly turned on and off in accordance with the brightness control signal, it is possible to raise the output voltage Vout to a desired voltage instantaneously. The same effect is achieved by using the output voltage detection circuit 24 shown in FIG. 2 . However, it is possible, by using the output voltage detection circuit 24 shown in FIG. 4 , to simplify the configuration of the soft-start circuit 20 , because the soft-start circuit 20 can be simply switched between the operative state and the inoperative state by checking the output from the output voltage detection circuit 24 on the rising edge of the brightness control signal. Furthermore, if the comparator 27 having a hysteresis characteristic is used for the output voltage detection circuit 24 and the set voltages Vset are set at 4.2 V and 3.0 V, it is possible to effectively use a lithium-ion battery of which a charge end voltage is 4.2 V and a discharge end voltage is 3.0 V. FIG. 5 is a circuit block diagram showing an electronic configuration of a power supply circuit of a second embodiment of the invention. In FIG. 5 , such components as are found also in FIG. 1 are identified with the same reference numerals and descriptions thereof will not be repeated. The power supply circuit shown in FIG. 5 is different from the power supply circuit shown in FIG. 1 and is provided with a feedback voltage detection circuit 28 instead of the output voltage detection circuit 24 . The feedback voltage detection circuit 28 is connected between the feedback terminal FB and the soft-start circuit 20 , compares the feedback voltage Vfb fed through the feedback terminal FB with the set voltage Vset, and feeds the comparison result signal to the soft-start circuit 20 . In the power supply circuit shown in FIG. 5 , the voltage to be used for deciding whether the soft-start circuit 20 is turned to the operative state or the inoperative state is changed from the output voltage Vout in FIG. 1 to the feedback voltage Vfb. Because the feedback voltage Vfb is proportional to the output voltage Vout, the feedback voltage detection circuit 28 can be realized by configuring a similar circuit as, for example, the output voltage detection circuit 24 shown in FIG. 2 or FIG. 4 and changing the level of the set voltage Vset. In this arrangement, since the power supply circuit shown in FIG. 5 functions in a similar manner and produces a similar effect as the power supply circuit shown in FIG. 1 , descriptions thereof will be omitted. FIG. 6 is a circuit block diagram showing an electronic configuration of a power supply circuit of a third embodiment of the invention. In FIG. 6 , such components as are found also in FIG. 1 are identified with the same reference numerals and descriptions thereof will not be repeated. The power supply circuit shown in FIG. 6 is different from the power supply circuit shown in FIG. 1 and is provided with an overvoltage protection circuit 29 capable of performing the functions of the overvoltage protection circuit 23 and the output voltage detection circuit 24 shown in FIG. 1 as well. The output voltage detection circuit 24 and the overvoltage protection circuit 23 shown in FIG. 1 feed out comparison result signals respectively after comparing the output voltage Vout with predetermined voltages preset for respective circuits. For this reason, the overvoltage protection circuit 29 shown in FIG. 6 can be easily realized by combining these two circuits. For example, as shown in FIG. 7 , it can be realized by extracting predetermined voltages, one for overvoltage detection and other for output voltage detection respectively, from resistors for dividing the output voltage Vout. This way makes it possible to simplify the circuit configuration of the power supply circuit. FIG. 8 is a circuit block diagram showing an electronic configuration of a power supply circuit of a fourth embodiment of the invention. In FIG. 8 , such components as are found also in FIG. 1 are identified with the same reference numerals and descriptions thereof will not be repeated. The power supply circuit shown in FIG. 8 is different from the power supply circuit shown in FIG. 1 and is provided with an input voltage detection circuit 30 instead of the output voltage detection circuit 24 . The input voltage detection circuit 30 is connected between the power supply terminal Vi and the soft-start circuit 20 , compares the input voltage Vin fed through the power supply terminal Vi with the set voltage Vset, and feeds the comparison result signal to the soft-start circuit 20 . In the power supply circuit shown in FIG. 8 , the voltage to be used for deciding whether the soft-start circuit 20 is turned to the operative state or the inoperative state is changed from the output voltage Vout in FIG. 1 to the input voltage Vin. The input voltage detection circuit 30 can be realized by configuring a similar circuit as, for example, the output voltage detection circuit 24 shown in FIG. 2 or FIG. 4 and changing the level of the set voltage Vset. At start up (time t 0 shown in FIG. 3 ), the input capacitor 2 is charged when the input voltage Vin is fed from the DC power source 1 . Accordingly, a terminal voltage across the input capacitor 2 increases. Therefore, before the input voltage Vin reaches its upper limit, the input voltage Vin detected by the input voltage detection circuit 30 is lower than the set voltage Vset shown in FIG. 2 or FIG. 4 . As a result, the input voltage detection circuit 30 feeds an “L” level comparison result signal to the soft-start circuit 20 , thereby causing the soft-start circuit 20 , at time t 0 on the first rising edge of the brightness control signal, to turn to the operative state. The soft-start circuit 20 , then, controls the drive circuit 13 so that the output voltage Vout increases gradually so as to limit the input current Iin (time t 0 to time t 1 in FIG. 3 ). After the startup, the input voltage Vin detected by the input voltage detection circuit 30 rises higher than the set voltage Vset. Because of this, the input voltage detection circuit 30 feeds an “H” level comparison result signal to the soft-start circuit 20 , thereby causing the soft-start circuit 20 to turn to the inoperative state. Consequently, the output voltage Vout rises instantaneously on the rising edge of the brightness control signal (time t 3 and thereafter in FIG. 3 ). In this way, the power supply circuit shown in FIG. 8 is able to increase the output voltage Vout gradually by activating the soft-start circuit 20 so as to prevent the input current Iin from increasing excessively at startup (time t 0 to time t 1 in FIG. 3 ), and increase the output voltage Vout to a desired voltage during the period in which the drive circuit 13 repeatedly turns the voltage boosting operation on and off in accordance with the brightness control signal (time t 3 and thereafter in FIG. 3 ). Furthermore, if the comparator 27 having a hysteresis characteristic is used for the input voltage detection circuit 30 in the power supply circuit shown in FIG. 8 and the set voltages Vset are set at 4.2 V and 3.0 V, it is possible to effectively use a lithium-ion battery of which a charge end voltage is 4.2 V and a discharge end voltage is 3.0 V. Furthermore, when the power supply circuit embodying the invention described above is incorporated in an electronic apparatus such as a portable telephone having the white light-emitting diodes LED 1 to LED 6 , it is possible to limit the current flowing through such a battery as a lithium-ion battery built in that electronic apparatus and make use of the battery until the voltage thereof reaches the discharge end voltage, while realizing such an electronic apparatus capable of regulating the brightness of the LED 1 to LED 6 . It is to be understood that the present invention is not limited to the embodiments as described above and that within the scope of the appended claims, the invention may be practiced other than as specifically described. As described, with this arrangement, it is possible for the soft-start circuit to become operative by detecting a low output voltage at startup and, thereby prevent a current flowing from the DC power source from becoming excessive. Once the output voltage has risen, by inactivating the soft-start circuit, it is possible to stabilize the output voltage instantaneously and supply a stabilized load current even when the drive circuit is repeatedly controlled on and off according to the external input signal. According to the invention, the voltage booster type switching power supply circuit activates the soft-start circuit only during the first rising period of the external input signal following startup. To perform this operation, there is provided the output voltage detection circuit for feeding out a comparison result signal by comparing the output voltage with a predetermined voltage, a feedback voltage detection circuit for feeding out a comparison result signal by comparing a voltage appearing across the output current detection resistor with a predetermined voltage, or the input voltage detection circuit for feeding out a comparison result signal by comparing the input voltage with a predetermined voltage. By this arrangement, it becomes possible, with a simplified circuit, to compare the output voltage, the voltage appearing across the output current detection resistor, or the input voltage with a predetermined voltage and, based on the comparison result, securely operate the soft-start circuit only during the first rising period of the external input signal.

The voltage booster type switching power supply circuit is provided with a drive circuit for controlling a switching element, a start/stop circuit for turning the drive circuit on and off according to a brightness control signal for adjusting a brightness of a light source of a liquid crystal display device, an output voltage detection circuit for detecting whether the output voltage is greater than a predetermined voltage and feeding out a result as a comparison result signal, and a soft-start circuit that does not operate when the comparison result signal is active on the rising edge of the brightness control signal, and that operates so as to increase the output voltage gradually when the comparison result signal is inactive on the rising edge of the brightness control signal.

FIELD OF THE INVENTION [0001] This invention relates to methods of electrolytic precipitation of a metal oxide. In particular, the invention relates to electrolytic precipitation of titanium dioxide (TiO 2 ). BACKGROUND OF THE INVENTION [0002] Metal oxides such as titanium dioxide and zinc oxide are commonly used in several industrial fields. For example, TiO 2 is used as an opacifier and/or white pigment in the coatings industry, as filler material in plastics, and as a photocatalyst for removing environmental pollutants. In the coatings industry, TiO 2 pigments provide efficient scattering of light to impart brightness and opacity. Titanium dioxide is typically commercially available in the anatase and rutile crystalline forms. Rutile TiO 2 is particularly desired because it scatters light more effectively and is more durable than the anatase form. [0003] TiO 2 (rutile and anatase) has traditionally been produced by two commercial processes, referred to as the “sulfate process” in which titanium ore is treated with sulfuric acid followed by crystallization and precipitation of TiO 2 and the “chloride process” in which titanium ore is treated with chlorine gas to produce an intermediate of TiCl 4 , which is oxidized to form TiO 2 . The cost of producing TiO 2 from these traditional processes has increased significantly and alternative routes for obtaining TiO 2 are being sought. SUMMARY OF THE INVENTION [0004] The present invention includes a method of producing metal oxide particles, comprising electrodepositing a metal oxide from an electrolyte solution onto a substrate to coat at least a portion of the substrate, whereby metal oxide seed particles are released into the solution; and precipitating metal oxide particles from the solution. Also included in the present invention is a pigment composition comprising rutile TiO 2 particles, wherein the particles are produced by electrolytic precipitation from an electrolyte composition comprising titanium oxychloride (TiOCl 2 ). BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is a scanning electron microscope image of TiO 2 particles produced according to the present invention; and [0006] FIG. 2 is a scanning electron microscope image of TiO 2 particles produced according to the prior art. DETAILED DESCRIPTION OF THE INVENTION [0007] For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements. [0008] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. [0009] In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. [0010] In one embodiment of the present invention, metal oxide particles are obtained in an electrolytic process in which a cathode (which may be composed of stainless steel) is electroplated with a metal oxide using a non-consumable anode (which may be composed of stainless steel or graphite). In an electrolytic cell containing an electrolyte solution, upon application of an electric current to the anode, the metal oxide plates out onto the cathode. The metal oxide formed on the cathode then seeds precipitation of metal oxide particles from the electrolyte solution. [0011] Metal oxides that can be electrodeposited onto a substrate and precipitate as metal oxide particles include oxides of alkaline earth metals (such as magnesium), transition metals (such as titanium and zirconium) and rare earth metals (such as cerium). The metal oxide forms on the cathode of an electrolytic cell, where the cell contains an aqueous solution of a salt of the metal. [0012] In one embodiment, a soluble salt of titanium can be electrodeposited from an electrolytic solution onto a cathode as TiO 2 and precipitated therefrom. A suitable soluble salt of titanium is TiOCl 2 . Other soluble salts of metals can be use to electrodeposit a metal oxide onto a substrate, such as zirconium oxide (ZrO 2 ) electrodeposited from a solution of zirconium oxychloride (ZrOCl 2 ). In general, suitable metals and soluble salts thereof useful in practicing the present invention may be those that form a coordination complex, also referred to as a Werner complex, or, as will be understood by those skilled in the art, are otherwise selected to electrodeposit as a metal oxide. As such, it should be appreciated that while the present invention is described in reference to electrolytic precipitation of TiO 2 , other metal oxides may be electrolytically precipitated according to the present invention from suitable aqueous solutions of salts of those metals. [0013] It has been found that upon electrolytic deposition of TiO 2 from an electrolyte solution onto a substrate (the cathode), TiO 2 seed particles are released from the deposited TiO 2 into the solution and precipitate as TiO 2 particles, typically sized less than 1 micron. The electrolyte solution includes a soluble salt of titanium, such as TiOCl 2 and may further include a reducing agent. Suitable reducing agents include oxidizing anions, such as an alkali nitrate, e.g. sodium nitrate. [0014] It has been found that TiO 2 particles will precipitate from electrolyte solutions containing 10 to 360 grams per liter (g/L) TiOCl 2 and 5 to 150 g/L sodium nitrate. By way of small scale example using a wire as a cathode, current densities of 0.3 to 1.5 amperes per square centimeter (A/cm 2 ) are sufficient to accomplish precipitation of TiO 2 according to the present invention. Electrolytic cell design and operating parameters thereof for larger scale production of metal oxides via the electrolytic precipitation method of the present invention will be appreciated by one skilled in the art. It has been found that the temperature of the electrolyte solution may be adjusted to control the particle size and particle size distribution of the precipitated TiO 2 particles. For example, in one embodiment, when the electrolyte solution is less than 150° F., the precipitated TiO 2 particles have a maximum dimension of less than 1 micron, such as 100-700 nm or 250-300 nm or 100-250 nm. The precipitated TiO 2 is produced as discrete particles (either directly or with milling) in the rutile form that are substantially in the shape of a sphere or spheroid, meaning that the particles appear to the eye as being spherical or spheroid. [0015] While TiO 2 may precipitate from a solution at elevated temperatures (over 150° F., typically at 185° F. or higher) without application of an electric current thereto, the resulting material normally forms agglomerates of particles, with the particles within the agglomerates having a primary particle size of over 1 micron, such as above 1.5 microns, which is unsuitable for use in coating applications and other end-uses. In the present invention, not only are the precipitated metal oxide particles discrete, the particle size may be tailored by adjusting the electrolyte solution temperature. For example, at electrolyte solution temperatures of 145° F., the average particle size of the discrete precipitated TiO 2 particles may be 100-250 nm. [0016] The precipitated TiO 2 produced according to the present invention may be included in conventional end-uses for TiO 2 as a complete or partial replacement of TiO 2 obtained by conventional processes and may be surface treated as is conventional in producing TiO 2 for industrial use. Such surface treatment may enhance the compatibility of the precipitated TiO 2 in coating systems, including aqueous and non-aqueous coating compositions. EXAMPLES [0017] The following Examples are presented to demonstrate the general principles of the invention. All amounts listed are described in parts by weight, unless otherwise indicated. The invention should not be considered as limited to the specific Examples presented. Example 1 [0018] A solution was made by adding 400 grams of deionized water into a glass beaker with a magnetic stir bar, and 100 grams of TiOCl 2 (available from Millennium Chemicals, Inc.) was slowly added to the deionized water. The solution was placed onto a magnetic stir plate capable of heating and agitation, then 40 grams of NaNO 3 (available from Acros Chemicals) was added to the solution and agitated for 15 minutes, giving a clear colorless solution. An electrolytic cell was applied to the solution. To the glass beaker, a four inch long ER316L 1/16″ stainless welding rod was suspended in solution and connected to a power source as a cathode. A graphite bar (1 inch wide by 4 inches long) was suspended in the solution and connected as the anode. The glass beaker with solution, cathode and anode was placed into a water bath and under agitation the solution was heated to 130° F. At 130° F. the solution was then electrified by passing 3.5 amps and 25 volts for 300 seconds. The maximum voltage achieved was 4.67 volts during the deposition process. Following deposition the bath temperature reached 139° F. and turned from clear colorless to light yellow. The solution was heated to 145° F. and the light yellow solution turned cloudy light yellow. The solution was removed from heat and agitation at 168° F. and cooled to room temperature. Upon cooling a white precipitate formed from the cloudy light yellow solution. The precipitate was evaluated by scanning electron microscope (SEM) and an average particle size of 100-250 nm was observed as shown in the SEM image of FIG. 1 . Comparative Example [0019] Example 1 was repeated but without use of the electrolytic cell. The glass beaker with solution was placed into a water bath, and the solution was heated under agitation. At 145° F., the solution turned from clear colorless to clear slightly yellow and increased in yellow color until the solution turned a cloudy milky yellow color at 185° F. The solution was removed from heat and agitation at 185° F. and cooled to room temperature. Upon cooling, a white precipitate formed from the cloudy milky yellow solution. The precipitate was evaluated by SEM and aggregates of particles having an average particle size of 1.5 μm was observed as shown in the SEM image of FIG. 2 . Milling the aggregates did not produce smaller discrete particles. [0020] While the preferred embodiments of the present invention are described above, obvious modifications and alterations of the present invention may be made without departing from the spirit and scope of the present invention. The scope of the present invention is defined in the appended claims and equivalents thereto.

Disclosed is a method of producing metal oxides, comprising electrodepositing a metal oxide from an electrolyte solution onto a substrate to coat at least a portion of the substrate, whereby metal oxide seed particles are released into the solution, and precipitating metal oxide particles from the solution. The precipitated metal oxide particles have a maximum particle size of less than 1 micron.

TECHNICAL FIELD The present invention relates to a method and apparatus for generating a crankshaft synchronized sine wave for use with active noise and vibration control systems in conjunction with internal combustion engines. BACKGROUND OF THE INVENTION Active noise control and active vibration control systems are employed to reduce noise and vibrations induced by internal combustion engines of vehicles. Active noise control systems utilize speakers and microphones to cancel sound emitted from the engine, which has a frequency that is synchronized with the rotational speed of the crankshaft. Active vibration control systems utilize active actuators, such as active engine mounts, to cancel engine induced vibrations, which also have a frequency synchronized with the rotational speed of the crankshaft. Therefore, the effectiveness of an active noise control and active vibration control system depends on an accurate crank angle signal. Many modern engines have a crankshaft position sensor operable to provide a crank pulse indicating crank angle. The crank pulse usually lacks the resolution sufficient for active noise and vibration control. Therefore, the crank pulse must be processed or conditioned to generate precise crank angle values for use with active noise and vibration control systems. Some engine manufacturers have developed AFM (Active Fuel Management, formerly called Displacement on Demand) systems to improve the fuel economy of internal combustion engines. An AFM engine operates in a normal mode (all cylinders are turned on) when power above a predetermined threshold is required and in an AFM mode (half of the cylinders are turned off) when power requirement is reduced. To generate the same level of driving torque with a reduced number of active cylinders, AFM mode produces a higher level of firing force, as a result of increased in-cylinder pressures, for each active cylinder. This higher firing force induces higher torque variations, which produce higher level of structural vibrations degrading noise and vibration, or N&V, performance. In addition, the AFM mode firing frequency reduces to half of the normal mode firing frequency, resulting in more excitation to structurally sensitive frequency ranges. Therefore, conventional passive approaches of vibration suppression may not meet the N&V requirement for both AFM mode and normal mode of engine operation. Engine induced N&V issues also arise in engines with high torque pulses including diesel and homogeneous charge compression ignition, or HCCI, engines. One possible solution to suppress the engine induced vibration is to apply active vibration control technology using smart actuators such as active engine mounts. There are several types of semi-active and active actuators that can be used for engine vibration suppression. An example of a semi-active actuator is a switchable engine mount whose damping characteristic may be electronically switched between soft and stiff by using electro-hydraulic or magneto rheological (MR) technology. With semi-active actuators, the vibration sensitivity may be switched as operating frequency changes, but may not completely cancel the engine vibration. Active actuators, on the other hand, produce force and/or displacement to counteract engine induced vibration. One type of active actuator is the Active Tuned Absorber (ATA), which utilizes inertial force within the actuator. Another type of active actuator is the Active Engine Mount (AEM). The AEM can generate displacement to counteract engine vibration and at the same time support the static load of the engine. SUMMARY OF THE INVENTION A method of generating a crankshaft synchronized sine wave signal for an internal combustion engine is provided. The method includes the steps of: A) sensing an observed crankshaft angle of the crankshaft; B) using a dynamic observer to generate an estimated crankshaft angle from the observed crankshaft angle; and C) generating the crankshaft synchronized sine wave signal as a function of the estimated crankshaft angle. The method may further include the step of communicating the crankshaft synchronized sine wave signal to at least one of an active noise control system and an active vibration control system. The method may also include generating an estimated crankshaft rotational frequency using the dynamic observer. The crankshaft synchronized sine wave signal may be generated by determining at least one of the sine and cosine of the estimated crankshaft angle multiplied by an order value, while the frequency of the crankshaft synchronized sine wave signal may be generated by multiplying the estimated crankshaft rotational frequency by an order value. An apparatus for generating a crankshaft synchronized sine wave for an internal combustion engine, having a crankshaft rotatably disposed therein, is also provided. The apparatus includes a sensor operable to sense the angular position of the crankshaft and communicate an observed crankshaft angle value and a controller operable to receive the observed crankshaft angle value. A dynamic observer is provided in communication with the controller and is sufficiently configured to generate an estimated crankshaft angle from the observed crankshaft angle value. The controller is preferably configured to determine the crankshaft synchronized sine wave as a function of the estimated crankshaft angle, and to communicate the crankshaft synchronized sine wave to at least one of an active vibration control system and an active noise control system. The dynamic observer may include at least one integrator module operable to generate at least one of an estimated crankshaft speed and the estimated crankshaft angle. Further, the dynamic observer may include a revolution pulse generation module operable to reset the estimated crankshaft angle once per revolution of the crankshaft. In one embodiment, the dynamic observer may be configured to determine an error value by subtracting the estimated crankshaft angle from the observed crankshaft angle. In this embodiment the dynamic observer may include a quantization module operable to quantize the estimated crankshaft angle prior to subtracting the estimated crankshaft angle from the observed crankshaft angle and a dead band operator module operable to account for a predetermined amount of error in the error value. The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of an engine incorporating a controller having a dynamic observer operable to provide control signals to an active engine mount system and an active noise cancellation system; FIG. 2 is a schematic illustration of a crankshaft pulse counter; FIG. 3 is a schematic illustration of a software implementation of a crankshaft pulse counter; FIG. 4 is a schematic representation of the dynamic observer, shown in FIG. 1 ; and FIG. 5 is a graphical illustration of a first order reference cosine of an engine operating at 600 RPM illustrating a control system with and without a dynamic observer. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 , there is shown a portion of a vehicle 10 having an internal combustion engine 12 mounted to a frame member 14 . The frame member 14 is supported by a suspension system 16 . Those skilled in the art will recognize that the suspension system 16 may include such components as springs, shock absorbers, tires, etc., which are not shown for purposes of clarity. The internal combustion engine includes an engine block 18 configured to rotatably support a crankshaft 20 . The crankshaft 20 has a target wheel 22 mounted thereon for unitary rotation therewith. A sensor 24 is located substantially adjacent to the target wheel 22 , and operates to provide an observed crankshaft angle value to a controller 26 . In the preferred embodiment, the internal combustion engine 12 will be a variable displacement engine, or operate in an active fuel management (AFM) mode of operation. Those skilled in the art will recognize that an AFM mode of operation refers to the disabling of half of the cylinders, not shown, of the internal combustion engine 12 during operating modes where the required power of the internal combustion engine 12 is operating below a predetermined value. That is, an internal combustion engine 12 having eight cylinders may disable four of the cylinders when the vehicle 10 is operating in a low engine load requirement mode of operation, such as a steady state highway driving schedule. Similarly, a six cylinder internal combustion engine 12 may disable three of the cylinders when the vehicle 10 is operating in a low engine load requirement mode of operation. The internal combustion engine 12 is supported on the frame member 14 by an active vibration control system, such as active engine mounts 28 . The active engine mounts 28 operate to cancel the vibrations imparted to the frame member 14 by the internal combustion engine 12 . The controller 26 operates to provide a control signal to the active engine mounts 28 . An active noise control system 30 receives control signals from the controller 26 and operates to cancel objectionable sound emitted from the internal combustion engine 12 . The active noise control system includes a microphone 32 , for sensing sound and communicating the sound signal to the controller 26 for processing, and a speaker 34 , for outputting the waveform operable to cancel the sound emitted from the internal combustion engine 12 . The controller 26 includes a dynamic observer 36 operable to process or condition the crankshaft angle signal provided to the controller 26 by the sensor 24 for subsequent communication to the active engine mounts 28 and the active noise control system 30 . The construction and operation of the dynamic observer 36 will be discussed in greater detail hereinbelow. Engine induced vibrations are synchronized with engine cycle and hence with crankshaft angle. For example, the active fuel management mode of a V6 internal combustion engine generates a vibration whose frequency is 1.5 times faster than crankshaft revolution frequency. Since the crankshaft frequency changes and the engine vibration is a function of crankshaft angle, it is more convenient to use order instead of frequency. Frequency is the number of oscillations per second, while order is the number of oscillations per one crankshaft revolution. Therefore, the active fuel management mode of a V6 engine has 1.5 th order vibration. Similarly, the active fuel management mode of a V8 engine has 2 nd order vibration. The main idea of vibration suppression using active engine mounts 28 is to generate a counter vibration to cancel the vibration produced by the internal combustion engine 12 . Since the vibration of the internal combustion engine is synchronized with the angel of the crankshaft 20 , the counter vibration also should be synchronized with the crankshaft angle. The engine generates p th order displacement z e =α o cos(pθ)+β o sin(pθ), where the magnitude and phase are determined by the unknown parameters α o and β o . Driven by the controller 26 , the active engine mounts 28 generates p th order displacement z m =α(pθ)+β(pθ), where the magnitude and phase are determined by the control parameters α and β. The control objective is to cancel p th order displacement z f =z e −z m of the frame member 14 . The ideal control parameters are α=α o and β=β o . However, the parameters α o and β o are unknown and the control algorithm is designed to find parameters α o and β o . Therefore, the control algorithm needs order reference sine and cosine from the crankshaft angle. To implement the control algorithm, unit cosine and sine synchronized with order multiple of crankshaft revolution is required. To obtain the order reference, the crankshaft angle must be measured in real time. Many currently produced internal combustion engines 12 provide a crankshaft pulse every six degrees of crankshaft angle, thereby providing sixty pulses per crankshaft revolution. However, typically there are two missing pulses every revolution indicating starting angle; consequently, there are only fifty eight pulses per crankshaft revolution, not sixty. The period of fifty eight teeth starting from any pulse is equal to one crankshaft revolution period. Once the crankshaft angle is determined, the order reference cosine and sine may be generated. Having order references, the control parameters α and β can be determined either by closed-loop control or by open-loop control. The frequencies of the firing induced vibrations of the internal combustion engine 12 are order multiples of crankshaft revolution. As stated hereinabove, order is defined as the number of oscillations per one crankshaft revolution, while the frequency is number of oscillations per second. Since the rotational speed of the crankshaft 20 (engine rpm) changes during operation, it is more convenient to use order as the frequency reference rather than absolute frequency. For example, the primary vibration frequency of a V6 engine is 3 rd order, which means the frequency is exactly three times the crankshaft revolution frequency. For a V6 engine operating in an active fuel management mode of operation with one bank of three cylinders disabled, the primary vibration frequency is 1.5 th order. Similarly, for a V8 engine, the primary vibration frequency is 4 th order and the primary vibration frequency of a V8 engine operating in an active fuel management mode of operation, having four cylinders disabled, is 2 nd order. In addition to the order, the phase of the vibration is fixed relative to the crankshaft angle because the firing events occur based on the 0-720 degree engine phase, based on a four-stroke mode of engine operation, which constitutes two revolutions of the crankshaft 20 . Considering the order and the phase together, the firing induced vibration is synchronized with the crankshaft revolution. The purpose of the control algorithm is to cancel fixed order vibration. Therefore, the control algorithm relies on order references that are unit cosine and unit sine signals of target order with fixed phase relative to the crankshaft angle. Once, the order reference is synchronized with the crankshaft 20 , the control algorithm finds magnitude and phase of the movements of the active engine mounts 28 relative to the order reference, so that the active engine mounts 28 can cancel vibration induced by the internal combustion engine. For this reason, the synchronization of order reference to engine phase is important to the control of the active engine mounts 28 . Referring to FIG. 2 , and with continued reference to FIG. 1 , a crankshaft pulse counter 38 is schematically illustrated. The observed angle of the crankshaft 20 can be measured by counting fifty eight crankshaft pulses. This can be done by using a counter 40 . The counter 40 is preferably operable to count the crankshaft pulses and reset itself when the counter value reaches fifty eight. The output of the counter is a six bit binary number indicating the angle of the crankshaft 20 . However, the starting angle is not deterministic because the counter 40 begins when it is powered asynchronous to other events. A micro-controller 42 reads the six bit binary number with a fixed sampling rate; however, the counter value is updated based on the crankshaft pulse event. The micro-controller 42 may be incorporated within the controller 26 or may be separate. The discrepancy of the crankshaft pulse event and the fixed sampling rate of the micro-controller 42 results in an asynchronous data transfer issue. A gray code encoder 44 and D flip-flops 46 are added to resolve the asynchronous data transfer issue between the counter hardware and the micro-controller 42 . After the counter value is fetched to the controller 26 , a gray code decoder 48 restores the original value of the counter 40 . Referring to FIG. 3 , and with continued reference to FIG. 1 , a software implementation of a crankshaft pulse counter is schematically illustrated. An alternative way of implementing the crankshaft pulse counter is to use a hardware interrupt 50 , which is provided by most micro controllers. FIG. 3 shows a schematic of an interrupt driven crankshaft pulse counter 52 . In this case, there is no need to use external counter hardware. Instead, the crankshaft pulse is directly connected to the hardware interrupt 50 to trigger the interrupt routine. The interrupt routine increases the counter value every time it is triggered. If the counter value reaches fifty eight, the interrupt routine resets the count value to zero. The counter value is stored in a register 54 so that the time based sampling routine can access the data. The entire control algorithm, except the crankshaft pulse interrupt routine, is driven by fixed sampling time. The time based sampling system reads the counter value once per sampling period. Because of the asynchronous sampling between counter update and counter value reading, the counter value reading of the fixed sampling system is very irregular although the actual counter value is regularly increased. A simple way to calculate an estimated crankshaft angle from the count reading is: θ ^ ⁡ ( k ) = 2 ⁢ ⁢ π 58 ⁢ y ⁡ ( k ) ( 1 ) where {circumflex over (θ)}(k) and y(k) are estimated crankshaft angle and the count reading at k th sample, respectively. However, Equation (1) has two issues. First, the estimated crankshaft angle is not smooth and the cosine and sine generated from this angle is rough or irregular. Second, since the control algorithm does not detect the missing tooth of the target wheel 22 and the estimated crankshaft angle is one revolution average of the crankshaft angle, ignoring the missing pulses distorts the sinusoids and results in performance degradation of the control system, which depends on the reference sinusoid. These issues can be resolved by using the dynamic observer 36 . For a constant speed, the discrete-time domain kinematics model of crankshaft rotation is as follows: θ( k+ 1)=θ( k )+2 πf ( k )/ f S ,  (2) f ( k+ 1)= f ( k ).  (3) where θ(k), f(k), f S are observed crankshaft angle, rotational frequency, and sampling frequency, respectively. Two states may be defined as follows: x 1 ( k )= N θ( k )/2π  (4) x 2 ( k )= Nf ( k )/ f S   (5) y ( k )= x 1 ( k )  (6) where the physical meaning of y(k)=x 1 (k) and x 2 (k) are the observed crankshaft angle in terms of the number of crankshaft pulses and crankshaft speed in terms of the number of crankshaft pulses per sampling time, respectively. Equations (4), (5) and (6) are then written in state space form: { x 1 ⁡ ( k + 1 ) x 2 ⁡ ( k + 1 ) } = [ 1 1 0 1 ] ⁢ { x 1 ⁡ ( k ) x 2 ⁡ ( k ) } , ⁢ y ⁡ ( k ) = [ 1 ⁢ ⁢ 0 ] ⁢ { x 1 ⁡ ( k ) x 2 ⁡ ( k ) } ( 7 ) To track y(k) with an observer technique. The dynamic model of the dynamic observer 26 is then: { x ^ 1 ⁡ ( k + 1 ) x ^ 2 ⁡ ( k + 1 ) } = [ 1 1 0 1 ] ⁢ { x ^ 1 ⁡ ( k ) x ^ 2 ⁡ ( k ) } + [ l 1 l 2 ] ⁡ [ y ⁡ ( k ) - y ^ ⁡ ( k ) ] , ⁢ y ^ ⁡ ( k ) = [ 1 ⁢ ⁢ 0 ] ⁢ { x ^ 1 ⁡ ( k ) x ^ 2 ⁡ ( k ) } ( 8 ) The error dynamics can be obtained by substituting Equation (8) from Equation (7) to yield: { x ~ 1 ⁡ ( k ) x ~ 2 ⁡ ( k ) } = [ 1 - l 1 1 - l 2 1 ] ⁢ { x ~ 1 ⁡ ( k - 1 ) x ~ 2 ⁡ ( k - 1 ) } ( 9 ) where {tilde over (x)} i (k)=x i (k)−{circumflex over (x)} i (k) The characteristic equation of the error dynamics (9) becomes: z 2 −(2−l 1 )z+(1−l 1 +l 2 )  (10) The observer parameter l 1 and l 2 can be designed as follows: A) Construct a continuous time characteristic equation by choosing desired natural frequency ω n and damping ratio ζ, i.e., s 2 +2ζω n s+ω n 2   (11) The damping ratio and the natural frequencies are tuning parameters for the dynamic observer 26 . B) Convert Equation (11) into discrete-time version to yield the corresponding discrete-time characteristic equation, i.e., z 2 −az+b  (12) C) Calculate l 1 and l 2 such that: l 1 =2 −a and l 2 =b+ 1 −a An exemplary calculation of l 1 and l 2 is as follows: Damping ratio: ζ=1 Settling time: t s = 4.6 ζ ⁢ ⁢ ω n = 0.1 ⁢ ( sec ) ⁢ ⁢ yields ⁢ ⁢ ω n = 46 ⁢ ( rad ⁢ / ⁢ sec ) Discrete sampling time: T S =0.0005 (sec) Discrete-time characteristic polynomial: z 2 −1.9545+0.955 Observer parameters: l 1 =455.e−4 and l 2 =5.e−4 The basic structure of the dynamic observer 26 has the form of Equation (8). However, the practical implementation requires several treatments. First, the estimated count ŷ(k)={circumflex over (x)} 1 (k), which corresponds to crankshaft angle, can increase without bound with time while the count reading y(k) is a repeating ramp of 0 to 57. To keep {circumflex over (x)} 1 (k) in range, the algorithm subtracts fifty eight counts from {circumflex over (x)} 1 (k), once every crankshaft revolution. The revolution pulse generation method is as follows: Initialization:           y_old = −1; Inputs:         y(k) : Count Reading Algorithm:         One_Rev_Flag = 0; If (y(k) < 0.5*y_old) One_Rev_Flag = 1;         y_old = y(k); Outputs:         One_Rev_Flag As an example of the revolution pulse generation method outlined hereinabove, as the count reading value y(k) resets from fifty seven to one, (y(k)<0.5*y_old) becomes true since one is less than 0.5 multiplied by fifty seven. Therefore, the output One_Rev_Flag is set equal to one indicating one revolution of the crankshaft 20 . Second, since the count reading y(k) is a quantized integer, the estimated count reading ŷ(k) should be a quantized integer to compare the count reading and the count estimates. Third, the estimated count ranges from zero to fifty nine as if there is no missing tooth on the target wheel 22 , while the count reading is zero to fifty seven with missing teeth on the target wheel. This will generate the output error of two even when the dynamic observer 36 is operating correctly. Referring now to FIG. 4 , and with continued reference to FIG. 1 , there is shown a schematic representation of the dynamic observer 36 of FIG. 1 . At block 56 the count reading y(k) is read into the dynamic observer 36 from the sensor 24 of FIG. 1 . Subsequently, the estimated count reading ŷ(k) is subtracted from the count reading y(k), via the subtraction module 58 , to determine an error count value e(k). As mentioned hereinabove, the count reading y(k) is a quantized integer; therefore, the estimated count reading ŷ(k) should be a quantized integer to compare the count reading and the count estimates. A module 60 is provided for the quantization of discrete values of the estimated count reading ŷ(k) into a stepwise function. The error count value e(k) is input to a dead band operator module 62 to account for missing teeth on the target wheel 22 . The output of the dead band operator module 62 is subject to gain modules 64 . An integrator module 66 is operable to provide the estimated crankshaft rotational speed {circumflex over (x)} 2 (k) in terms of crankshaft pulses per sampling time. The estimated rotational frequency of the crankshaft {circumflex over (f)} c (k) is output from the integrator module 66 as indicated by block 68 . The output of the integrator module 66 is input to an integrator module 70 , which is operable to provide an estimated crankshaft angle {circumflex over (x)} 1 (k), the value of which is fed back to the quantization module 60 for determination of the error count value e(k). Further, a revolution pulse generation module 72 is provided to reset the estimated crankshaft angle {circumflex over (x)} 1 (k) every time the counter reading at block 56 resets to zero in accordance with the revolution pulse generation method described hereinabove. The output of the dynamic observer 36 is the estimated crank angle {circumflex over (θ)}(k), as illustrated by block 74 . The estimated crankshaft angle {circumflex over (θ)}(k) is smooth and synchronized with the true or observed crankshaft angle θ(k), but with an unknown and constant phase delay. The crankshaft reference cosine and sine of order p can be generated from the estimated crankshaft angle, i.e., cos p ( k )=( p {circumflex over (θ)}( k ))  (13) sin p ( k )=( p {circumflex over (θ)}( k ))  (14) Where cos p (k) and sin p (k) are p th order unit cosine and sine, respectively. Also the frequency of p th order reference f p is: f p =p{circumflex over (f)} c ( k )  (15) FIG. 5 shows the comparison of the first order reference cosine with, illustrated by line 76 , and without, illustrated by line 78 , the dynamic observer 36 . As shown in FIG. 5 , the dynamic observer 36 discussed hereinabove compensates for the missing teeth of the target wheel 22 and smoothes the roughness of the crankshaft pulse signal due to asynchronous sampling. Similarly, a p th order reference cosine and sine can be generated from the estimated crankshaft angle {circumflex over (θ)}(k) by multiplying p by the estimated crankshaft angle {circumflex over (θ)}(k) and taking cosine and sine thereof. The present invention enables generation of crankshaft synchronized reference order sinusoid for use in control systems such as the active engine mounts 28 . The present invention resolves the issue of data transition between event based sampling of crankshaft pulse count and time based sampling of active vibration and noise control system. The method also smoothes the estimated crankshaft angle by using the observer technique to generate a smooth and precise reference sinusoid in a time based sampling system. Finally, the estimated crankshaft angle {circumflex over (θ)}(k) does not detect the initial crankshaft position and hence includes an unknown, but constant, angle offset from the actual crankshaft angle. However, the unknown angle offset does not affect the control system since the control algorithm automatically compensates for the unknown offset. Although the forgoing discussion relates generally to a target wheel 22 having fifty eight pulses per revolution of the crankshaft 20 , those skilled in the art will recognize that the present invention may be used with target wheels having an alternate number of pulses per revolution of the crankshaft while remaining within the scope of that which is claimed. While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.

A method of generating a crankshaft synchronized sine wave signal for an internal combustion engine is provided. The method includes the steps of: A) sensing an observed crankshaft angle of the crankshaft; B) using a dynamic observer to generate an estimated crankshaft angle from said observed crankshaft angle; and C) generating the crankshaft synchronized sine wave signal as a function of the estimated crankshaft angle. The crankshaft synchronized sine wave signal is preferable output to at least one of an active vibration control system and an active noise control system. An apparatus for generating a crankshaft synchronized sine wave for an internal combustion engine according to the method of the present invention is also disclosed.

RELATED APPLICATION This application is a continuation of U.S. patent application Ser. No. 10/136,845, filed on Apr. 30, 2002 now abandoned, entitled “INTERACTIVE ELECTRONICALLY PRESENTED MAP,” which claims priority to U.S. Provisional Application No. 60/287,339, filed on Apr. 30, 2001, entitled, “INTERACTIVE ELECTRONICALLY PRESENTED MAP,” which is hereby incorporated by reference in its entirety. COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. BACKGROUND OF THE INVENTION The invention disclosed herein relates to electronic presentation and use of maps and other area representations (including geographic and non-geographic areas), and related information, and to the interactive use thereof. The presentations may be provided to users via any type of communications or computer network (including wired and/or wireless), such as an intranet, LAN, WAN or the Internet, an system including interactive television, or may be provided in local storage, e.g., in a client or server hard disk or CD, etc. Electronically presented maps are available over the Internet. See, for example, www.mapquest.com, www.mapsonus.com, www.maps.expedia.com, www.maps.yahoo.com (accessed through www.yahoo.com), www.maps.com, www.maps.excite.com, (accessed through www.excite.com), www.mapblast.com, and www.zip2.com. Also see U.S. Pat. Nos. 4,974,170, 5,682,525 and 6,148,260. A magnifier feature that facilitates use of an electronically presented map is disclosed, for example, in U.S. Pat. Nos. 5,818,455. 4,800,379 also discloses use of a magnifier in connection with display of an image. SUMMARY OF THE INVENTION The present invention provides computerized systems and methods for providing an electronically presented interactive area representation, such as a map, and information associated therewith. In some embodiments, a user can select text, imagery, or other information presented on the map and associated with one or more items or locations, causing presentation of information relating to the associated one or more items or locations, such as appropriate contact information or a hyperlink to an appropriate Web site. Additionally or alternatively, a user can input or select, based on a query or otherwise, information relating to one or more items or locations associated with text, imagery, or other information presented on the map, causing presentation of an indication of one or more locations of the associated text, imagery, or other information on the map. In some embodiments, internal navigation within the map can be provided using a magnifier that highlights, indicates, or otherwise defines a portion of the map, causing a simultaneous magnified presentation of the defined portion to be provided, which magnifier can be moved smoothly over the map. In some embodiments, animated images can be presented to appear to move over the map and can simultaneously appear to move through magnified presentations. In some embodiments, the animated images can include advertisements which can be related or unrelated to items or locations associated with text, imagery, or other information presented on the map. The invention provides improvement in the presentation and ease of use of electronically presented maps and other area representations, and information provided by and in association therewith. “Map” and “area representation” are used herein in a broad sense and may encompass a variety of geographic and non-geographic areas. The invention presents information in the area representation itself as well as other information associated with the area representation, provides a unique format for electronically presenting and interactively using an area representation, and uniquely associates information and area representation locations and/or parts. In some embodiments, the area representation represents a site and the item information relates to locations within the site, or a virtual area, or a printed page, etc. Discussion of the invention in connection with a map is illustrative of other area representation applications. In a preferred embodiment, the invention enables users to obtain information about an area, such as a neighborhood, community, village or city, etc., represented by an electronically presented map, in an easy and enjoyable manner, similar in essence to actually walking through the area of interest. Maps and other area representations may be provided in accordance with the invention over a network (including wired and/or wireless), e.g., an open or closed network, or locally, e.g., on a CD or diskette or loaded into local hard drive or electronic memory. The invention provides, e.g., digital signals from which an area representation can be electronically displayed, and digital signals representing associated information, such as text, related in some way to at least one of the locations of the area representation. Sets of digital signals representing supplementary or additional information such as text words, phrases, images, or their combination at least partly containing text, words, images, or characters, etc. are associated with respective location information corresponding to respective locations of the area representation when displayed. Thereby, information associated with a location of an area representation can be displayed based on the location's location information, and location information can be obtained based on associated supplementary or additional information. The digital signals and information may be stored in one or more databases including relationship between and among digital signals and information. Supplementary information, additional information and item information can include voice information, which can be presented, for example, through speakers. The location information can be obtained from the input of a position indicator device such as a mouse, digitizer, touch screen, touch pad, keyboard, voice recognition system, etc. Associating location information obtained from a position indicator with supplementary or additional information allows the information to be accessed from the location information, and also allows the position indicator to be positioned at a location on a displayed area representation related to the associated information. This may be done on a static or dynamic basis, e.g., when a position indicator is in a fixed location or while it is moving. The invention in one of its aspects provides two-way interactivity, i.e., associated text or other information can be accessed from location-related information, and a desired location on an area representation can be identified from text or other information. The two-way interactivity thereby allows a user to take advantage of a displayed area representation as well as information available through the system about items associated with locations on the area representation. For an area representation embodied by a map, placing the position indicator on a desired location on the displayed map can be used to display associated information, and entering or selecting displayed information, image or images, text, or characters can be used to position the position indicator on the map at a location related to the entered or displayed information, image or images, text, or characters. The invention also provides a magnifier feature which can be used with the area representation and/or the text. In one implementation, digital signals are provided representing two versions of an area representation, which when displayed provide a smaller, or unmagnified, version and a larger, or magnified, version of at least a portion of the area representation. The magnifier feature highlights or otherwise defines the portion of the smaller version of the area representation, and software associates locations on the two area representations and provides a display of the smaller, or unmagnified, version, or view, of the area representation with a highlighted or otherwise defined portion and, simultaneously, a magnified version, or magnified view, of the smaller, highlighted portion. A location on either or both versions of the area representation is related to supplementary or additional information and text as described above. The invention in a preferred embodiment displays a composite view of a smaller area representation, a portion of the area representation enlarged or magnified, and associated text information. The invention in another aspect provides moving images in association with an area representation and the magnifier feature. Separate scripts are used to move the respective images relative to the respective smaller and larger versions of the area representation. The images are relatively scaled in generally the same proportion as the two versions of the area representations. Movement of the images is tracked along corresponding paths on respective area representations. This provides for a smaller version of the image to move relative to the smaller version of the area representation and the larger image to move related to the larger version of the area representation. When a portion of the larger area representation is displayed together with the smaller area representation, the image, e.g., appears to enter the larger version of the area representation synchronized with movement of the image on the smaller area representation. One way to accomplish this is to provide, for each image, lists of points defining movement of the respective image relative to the respective area representation. The moving images may be implemented in any suitable manner, e.g., using sprites. In accordance with the invention, an electronic area representation is provided of an area and item information thereon relating to one or more items associated with the area. The item information for different items is at different locations on the area representation. In response to user input selecting item information, additional information relating to the item whose item information was selected is provided, preferably together with the area representation, e.g., on display including the area representation and the additional information. In this embodiment, in which the area representation preferably is a map that represents a geographic area, there is a relationship between the item information and the additional information which is preferably implemented by associating the location of the item information with the related supplementary or additional information. In another embodiment, the additional information is associated with item information, e.g., via the location of the item information, so that user selection of such additional information provides on the area representation an indication of the item information relating to the selected additional. This embodiment includes a relationship between the item information (e.g., its location) and the additional information which is preferably also implemented by associating the location of the item information with the related supplementary or additional information. In this embodiment and the embodiment described immediately above, the relationship operates in opposite directions. In still another embodiment, the relationship between item information (e.g., its location on the area representation) and additional information is two-way, i.e., this embodiment includes a relationship between the item information (e.g., its location) and the additional information that operates in both directions. This embodiment thereby provides the two-way or both direction functionality described herein. In one embodiment, the invention also provides for highlighting a minor portion of the electronic area representation, and providing together with in the electronic area representation a magnified representation of the highlighted portion outside the area representation. The highlighted portion may be positioned on the electronic area representation by means of an input device and moved, preferably, continuously on the electronic display of the area representation. The invention may provide in some embodiments for moving an image with respect to the area representation including through a highlighted portion and through a magnified representation of the highlighted portion, the image being represented magnified in the magnified portion as compared to the image moved with respect to the area representation. The invention provides a computer readable medium or media which causes a computer to provide the functionality described herein, and systems and computers and methods, as described herein, that provide such functionality. Preferably, the electronic area representations are presented or displayed on any suitable display device, e.g., a computer monitor or television display device. Selection of item information and additional information may be made by any suitable input device, e.g., computer input devices such as keyboards, pointing devices (mouse, digitizer, touch screen, touch pad, etc.), voice input and recognition devices, etc. User input, as described herein, may also include a query requesting information related to item information on the electronic representation or additional information. A map embodiment of the invention is described below with the understanding that such description applies where appropriate to other area representations which can be implemented from the disclosure herein by those of skill in the relevant art(s) without undue experimentation. In a preferred embodiment, the invention associates a map location and/or map part with information (“item information”) relating to some place, item, thing or person, which can be real, imaginary, or otherwise, located at or associated with a map location and/or part of the map. “Item information” as used herein is meant in a broad sense, and encompasses information relating to persons, places, sites, items, points of interest, things, objects, etc., (e.g., for business, cultural, architectural, historical, recreational purposes, etc., residences, events, famous or historical persons, persons associated with a business or residence, etc.). (This type of association may also be applied to other area representations.) Item information may include one or more of the following: a category, name, image, or other identification of a person, place or thing, a physical and/or electronic address thereof, contact information thereof, and information describing the nature or attributes, etc., thereof, at least containing text, characters, or one or more images. The invention provides for associating such information and locations and/or parts of an electronically presented map so that one can obtain a display of the item information interactively from a view of a map, or one can obtain a view of a map, i.e., and relevant part thereof, or map location interactively from the associated item information, or both. This is accomplished by associating each item with coordinate information obtained from data input by a positioning device for a position indicator, so that the coordinate information can be used to retrieve item information, and item information can be used to obtain related coordinate information. Also, a search feature may be provided to identify desired item information and map locations. Thus, in response to a query, e.g., a category query, which query can in some embodiments be input by voice using, for example, a voice recognition device, the search feature provides a list of all item information responsive to the query. The query can also be the name of a specific item, and the response would be a display of the associated item information and positioning of the position indicator at the location on the map of the queried item. In addition, more sophisticated querying, as known in the art, is possible. For example, in some embodiments, users can execute queries utilizing a search function, search engine, or other search tool, such as a simple word search engine, or a boolean search engine. The search engine can be accessible, for example, from the map or a portion of a display outside the map. In addition, the search engine can be customized to the map, or can be a general search engine, such as any Internet search engine. In some embodiments, the search engine can be used to help provide the user with information useful in specifying appropriate categories, items, or location-related information, to be used in acquiring specific desired information in accordance with the various features of the invention. Furthermore, in response to a user query, including a voice query input through a voice recognition device, or other user input or selection, submaps can be presented. For example, in some embodiments, a user can query the locations of restaurants in a certain portion of the area representation, and a submap excluding items other than restaurants may be presented. As another example, a user can query the location of restaurants in the entire area representation, and an area representation can be presented to the user that is similar to the originally presented area representation, but which omits items other than restaurants, or upon which restaurants are highlighted or otherwise made obvious, or upon which items other than restaurants are shown in a grayed-out or otherwise less obvious or obtrusive manner. In some embodiments, a user can query, for example, the location of the nearest restaurant to a presently positioned position indicator on the area representation, in response to which a position indicator such as a magnifier is re-positioned by the system to the nearest restaurant on the area representation. Such embodiments can be implemented, for example, utilizing one or more text or other databases which contain information regarding the nearest items, or nearest items from particular categories, with respect to various map locations, or can be implemented by utilizing programming to calculate distances to items from map locations based on, for example the coordinates of items compared to the coordinates of a location on an area representation, which location can be defined with reference to a position indicator, magnifier, or in some other manner. The item information is associated with a person, place or thing on, at, near or surrounding a position indicator on an electronic display of a map, e.g., a cursor on a computer monitor that is positionable using an input device such as a mouse, digitizer, keyboard, touchpad or touch screen. For example, item information is displayed correlated to the position on the map of the position indicator. As discussed above, the invention provides a magnifier feature, or magnifier, which can be one form of position indicator, in conjunction with an electronically displayed area representation to display a selected part of the area representation magnified. Discussion of the magnifier feature in connection with a map is illustrative of other applications. The map part that is shown magnified may be selected using a position indicator, as described above, on an electronic display of the map. In a preferred embodiment, the magnifier feature highlights or marks in some manner that part of the map which will be displayed magnified. The area highlighted may be a geometric area such as a circle, triangle or rectangle. The area may be highlighted by color, by being darker or lighter than the surrounding area, a line or lines or indicia defining an outline shape, a flashing area or cursor, etc. This highlighted or defined area or map part can be referred to herein as a magnifier or magnifier feature. In the preferred embodiment the shape of the part of the map displayed magnified corresponds to the shape of the magnifier, e.g., circular. Many of the functions of a magnifier can be accomplished by different position indicators, and many of the features of any position indicator can be accomplished by a magnifier. Unless indicated otherwise or from context, the term “position indicator” encompasses a magnifier. Therefore much of the description below regarding a magnifier applies to any position indicator as well, and vice versa. Moreover, in some applications, association of information and location can be used without a magnifier, or a magnifier could be used without association of information and location. The magnifier may be positioned with respect to a normal or unmagnified presentation of the map in any suitable fashion. (Normal, “unmagnified” and “magnified” are meant in a relative sense. For example, an unmagnified presentation of a map may be a reduced version of a normal size map and vice versa, where by comparison, one map appears magnified). This may be accomplished, for example, by providing scaled versions of maps. For example, movement of the magnifier can be controlled by an input device. The magnifier may also be embodied by an object that is positioned using the cursor and an input device. For example, with a mouse as the input device, the magnifier can be positioned using mouse operations such as “point and click” and “drag and drop”. In the preferred embodiment, the magnifier is made of two sprites; one performs a highlighting function, e.g., provides a yellow or other highlighting color to provide a visual definition, and the other provides shape, e.g., to the highlighted area and may be a circular bitmap. The magnified part of the map may be displayed within a normal or unmagnified presentation of the map, either overlaying the map part to be magnified, or displaced therefrom, or outside of the displayed map part. If the magnified map part is displayed within the map, the position thereof preferably is displaced from the position of the magnifier, and the position of the magnified part changes in accordance with the position of the magnifier. In the preferred embodiment, the magnified map part is displayed outside of the map itself, and a magnifier corresponding in outline shape to the magnified map part, e.g., circular, triangular, rectangular, etc. is shown highlighted and unmagnified. This arrangement permits simultaneous presentation of a highlighted umnagnified map part and the corresponding magnified map part without obscuring any part of the presented map. In other embodiments of the invention, the magnified map part or magnified view is presented as overlying and obscuring or partially obscuring at least part of the a portion of the unmagnified version highlighted or otherwise defined by the magnifier. For example, the magnified view can be presented as obscuring the entire defined portion. For instance, a magnifier can be implemented as a circle defining the portion of the unmagnified version. The defined portion of the unmagnified version can be obscured and apparently covered by the magnified version, the magnified version showing a magnified view of at least a part of the defined portion. Such an implementation, to a user, gives the an appearance resembling that of a magnifying glass situated above the defined portion of the unmagnified view, and giving a magnified view of at least a part of the defined portion. Alternatively, the magnified version can be displayed so that a part of the unmagnified version appears to cover a part of the unmagnified map, while a remainder of the unmagnified version is displayed “off” of the unmagnified map. In some embodiments of the invention, the magnifier can be moved in any direction using, for example, a mouse or other pointing device, such that the magnifier appears to move fluidly and smoothly over the unmagnified map, defining ever-changing portions of the unmagnified map, giving an appearance, in some embodiments, resembling physically moving a magnifying glass over a map. Simultaneously, the magnified version of the defined portion is displayed, whether being displayed over the defined portion or separately or partially separately from the unmagnified map. As the magnifier is moved over the unmagnified map, smoothly changing the defined portion, the magnified version smoothly changes accordingly, to display a smoothly changing magnified version which tracks and corresponds with the defined portion. As described above, in certain embodiments, the unmagnified map is displayed, or at least partially displayed, simultaneously with the magnified version. As such, a user is provided with the ability to see where the magnifier is on the unmagnified map as the magnifier smoothly moves over the map. The user can also, of course, view the magnified version at any time, conveniently being able to perceive, by reference to the unmagnified map including the magnifier, the location on, or the portion of, the unmagnified map that corresponds to the magnified version. The above-described embodiments, via the fluidly movable magnifier and corresponding magnified version, provide internal navigation within the unmagnified map. In some embodiments, the magnifier can be replaced with any indicator of a portion of a mapable area of any sort, and the magnified version can instead be any more detailed version of the mapable area. As just one of many potential applications, in some embodiments the invention provides internal navigation within a Web page, whereby, for example, a magnifier can be moved over features such as text, icons, images, or other representations on the Web page, to visually define such features, causing simultaneous display of views which correspond to the defined feature or features, which views can be, in varying embodiments, for example, magnified or more detailed views of the defined features, or other views which provide information associated with the defined feature or features. Similar to providing for the display of item information that is associated with the position of a position indicator without a magnification feature as discussed above, the invention provides for the display of item information associated with the magnified map part or designated by a magnifier. Descriptions herein of the relationship of displayed item information and the position of a position indicator apply to embodiments that include or do not include the magnifier feature and/or a magnifier unless indicated otherwise or by the context. Displayed item information changes to correspond to item information related to a re-positioned position of a position indicator. Displayed item information may change with, and track, movement of the position indicator, and/or displayed item information may change for each new stationary position of the position indicator. The associated item information may be displayed automatically or in response to an input such as a mouse operation (e.g., point and click or drag and drop) or keyboard entry. For example, new item information corresponding to the position of the position indicator on the map is displayed after the position indicator remains stationary at a new location for a given time. The invention also provides for movement of the position indicator to the associated position on the map in response to selection or input of item information. Choosing an entry or listing, e.g., in a categorical directory, causes the position indicator to move to the appropriate location on the map, and conversely, positioning the position indicator on the map causes one or more of the listing of items related to the categorical directory to be displayed. Examples of categories include those typically found in a telephone yellow pages book or electronic listing, e.g., food stores, drugstores, post offices, automobile rental companies, restaurants, museums, theaters, etc. Categories may also include items not typically found in a telephone yellow pages book, such as parks, points of interest, items in tourist guides, etc. for example. In the preferred embodiment, item information for a position map is contained in a character-based or text database, and graphics for the map is contained, e.g., in conjunction with a graphic file or files. In one embodiment, two graphics files of maps are displayed; a “magnified view” and an “unmagnified or normal view”, the magnified view being, e.g., four times the size of the unmagnified view. In addition, the system also displays item information associated with these views. By using the position indicator's coordinates to index item information within a text and/or character-based and/or graphics and/or image database, specific item information tagged to regions of the magnified view (and indirectly to regions of the unmagnified view) is displayed to the user when the cursor enters regions of the unmagnified view (by simple index look-up or other text retrieval method). Conversely, if the user selects specific displayed item information, the system retrieves and displays the graphical information relating to the region associated with the item information (e.g., by placing the magnifier at the relevant location on the unmagnified view and displaying the corresponding magnified view). Thus, item information can be retrieved and displayed by selecting a region of the unmagnified view, and a region of the unmagnified view (and the corresponding magnified view) can be retrieved and displayed by selecting specific item information. Further, in one embodiment the entire unmagnified map is displayed, but only a portion of the magnified map is displayed at a time. Additionally, the portion of the magnified view displayed is circular with a mask revealing the magnified area corresponding to the unmagnified area under the magnifier (i.e., the magnified view is based on the ratio of the maps' sizes—e.g. four to one). Alternatively, a single graphic file can be stored, and scaling can be used to obtain a larger or smaller image than the one stored in the graphic file. Users are, therefore, able to simultaneously view item information associated with regions on the unmagnified and/or magnified map (such as contact information relating to buildings, an image of the buildings or a related person or persons), and link to a web site with a mouse click. In embodiments including the magnifier feature, the graphic information may be viewed magnified together with the associated item information. Alternatively, users can explore a city by category (e.g., restaurants, schools, etc.) and view the location and/or map part (magnified and/or normal) and relevant information associated with each listing under the category. A feature of the invention is associating a hyperlink with an image, such as a building, which provides the ability to access selected information or a web site associated with the building (or its occupants) by clicking (or double-clicking) an image (magnified or normal or unmagnified) of the building, or by clicking (or double-clicking) an associated item information portion. In the preferred embodiment, a listing can be selected, e.g., by mouse clicking, either the graphical representation of the listing on the map or a item information listing, to activate a hyperlink to further information provided for or about the listing. For example, the hyperlink can be a URL, and mouse clicking can cause an Internet-enabled device to request the web page represented by the URL. This hyperlink is provided as all or part of the item information associated with the listing. In one embodiment, moving objects appear in the unmagnified view and/or in the magnified view, and preferably in both. In a preferred embodiment, a moving object displayed in an unmagnified view will have a similar appearance and movement in a magnified view. The objects may additionally display messages to the user and/or include advertisements. The moving objects can be in any image and may include images of modes of transportation (e.g., planes, hot air balloons, cars, etc.), people, animals, or objects (e.g., a baseball hit outside of a stadium). Each moving object is implemented as a sprite (i.e., instances of media elements) through algorithms that generate points in lists (i.e. x/y coordinates) that make up location paths that the balloons, blimps, etc. are programmed to follow. The invention also provides for the display of the map in perspective and in a distinctive style of illustration. Some other style of illustration or conventional two-dimensional bird's eye view of, e.g., the community could be used in an alternative implementation of the invention. The invention also provides methods and systems for improving the effectiveness of advertising. Unlike banners and other forms of advertising that are currently being used on web sites, these ads are naturally blended into the map's scenery and can even potentially mimic advertisements posted at “actual” locations. For example, if the Burnett Group posted an advertisement in Times Square during June 2001, the company could also post the same advertisement at the Times Square location on an electronically displayed map during that same time period. Accordingly, there are a variety of ways that companies can advertise on an electronically displayed map e.g., billboards, moving objects, etc.—that are effective from a marketing standpoint and engaging from a user's perspective. One method provided by the invention comprises including item information at a plurality of locations on the electronic representation relating to a product or service to be advertised, in response to user selection of a location on the electronic representation or additional information as described herein, providing additional information or an indication of item information, as described herein, having the advertising. The additional information provided in response to user selection is preferably presented outside of and simultaneously with the electronic representation of the area. Another advertising method involves moving an image over the electronic display of the map over the map and providing advertising to move with the image. The moving image and associated advertising can also be provided in the advertising method described above. The methods preferably also include arranging for a financial benefit for presenting at least one of the item information and the additional information. The financial benefit may be remuneration to a party who provides advertising that is accessible for viewing by appropriate persons. Advertising can be sold, for example, by a map provider, at fixed locations, or in connection with a moving object. In some embodiments, a map provider is provided with benefit, such as a fee, to include an animated image providing advertisement, the benefit being provided, for example, by an entity with an interest in having the advertisement presented. Different fees can be charged depending upon circumstances. In addition, advertisements can be related to for-profit or not-for-profit enterprises or causes. The invention also provides a business method in which advertising is presented on a map and the sponsor of the advertising is charged a fee for the advertising. The advertising may be displayed in a selected stationary location or locations on the map, e.g., on a billboard or sign, or on a moving object, e.g., a moving graphic representation such as a hot air balloon, or blimp, or airplane moving in any selected direction relative to the map, or boat moving on a body of water (if the map includes or borders on a body of water), or a vehicle or pedestrian moving on streets or highways on the map, etc. In various embodiments, advertising may be static, dynamic and/or animated (changing images and/or text and/or multimedia), accompanied by sounds and/or music. Different fees may be charged depending upon the location of the advertisement, size of the advertisement, the time the advertisement is to run, etc. For example, higher fees are charged to the more frequented areas, or higher fees are charged to advertise at a building, e.g., by the building's main tenant, etc. Also, higher fees can be charged to advertise a location in the same time period in which an event is occurring at the location, etc. Similarly, the categorical directory could contain display advertising, which could itself take advantage of multi-media possibilities, such as animation, music, sound, voice-overs, broadband streaming audio and video, film clips, etc. The following examples illustrate the advantages of the invention. Upon selection or input of the category “theaters”, a list of theaters within the geographic area represented by the displayed map will be displayed. Selection of a theater from the list will cause the position indicator to move to the area in which the theater is located, and that area will also be displayed magnified. Thus, a listing selected from a category directory causes the position indicator to move to the listing's location on the map, and the associated area to be displayed magnified. In addition, a person (i.e., a “user”) working, living, or visiting in or near a geographic area may want to know where he or she may purchase a gift. The user may want to determine what stores are within a three-block radius of his or her office, home or hotel. After accessing the relevant map, the user may simply move the position indicator around the area of the interactive map where he is located and view images of all of the stores and associated item information. As the position indicator is moved, item information relating to buildings within the highlighted area is simultaneously displayed for the user. After exploring an area of interest, a user may select a site to visit for the purpose of selecting a gift to purchase. At this point, the user may not have decided on a particular gift, but has decided that a store is likely to have the type of article that he or she may be interested in purchasing. On the other hand, if the user has a specific gift in mind, such as personalized stationary, the user can access the appropriate category (e.g., “stationary”), view a list of stores offering stationary in the geographic area, and select a store of interest, e.g., stores offering stationary such as “City Stationers.” Once the user clicks on “City Stationers,” the position indicator moves to the store's location on the map. The user will then be able to see where the store is located relative to his or her location, and all relevant information about the store (e.g., contact information). Other uses include, for example: tourists interested in visually exploring a city before deciding upon an itinerary, someone in need of medical care interested in finding the hospital closest to their location and the hospital's emergency information, someone interested in moving to a city who would like to find the names and locations of all real estate agents within a ten block radius of a specific high school, etc. The list of potential uses is essentially limitless. Furthermore, the invention can provide users with a tremendous variety of information. For example, users can simultaneously obtain information regarding: the location of businesses and their contact information and web sites, the location of public transit services and their hours of operation, the location of hospitals and the emergency numbers, the location of parks and their available facilities and hours of operation, etc. In addition, animation, sound, and other added enhancements can be added to the site. In alternative embodiments, graphic information may represent any region, e.g., cities, rural regions, bodies of water, areas in space, etc. Moreover, the text information may contain any information associated with any part of the region. For example, alternative implementations may include additional categories such as parks, hospitals, famous landmarks, subway stops, etc. Further, alternative embodiments may include images associated with any region. For example: images of animals may be displayed on a map showing where the animals live or are located in a zoo or a forest; similarly, images of U.S. presidents or movie stars may be displayed on a map of cities (or a city or area) associated with the Presidents or movie stars, etc. For example, images of movie stars may be displayed on a map of the Hollywood area. Moreover, the item information associated with these images may contain any information associated with the images (e.g., information about animals, the term of each president, films the movie stars appeared in, etc.). Although the invention is mainly described in connection with geographical area representation such as maps or diagrams of geographic locations, and persons, places and things and information associated therewith, “area representation” is meant in a broad sense. For example, a printed circuit board with electronic components thereon can be considered an area representation, and information related to the electronic components or circuit parameters, etc., can be associated with the location of the electronic component. Movement of a position indicator and/or a magnifier could provide access to this information, as described for maps, and could provide magnified views, as described for maps. “Area representation” can be extended to layers of integrated circuits, or any appropriate object, assembly or topography having area, including, for example, three dimensional objects, and whether or not relief is also represented with any area. Thus, celestial representations are also encompassed within the term “area representation” even though celestial bodies area separated by three dimensional spaces. In such an embodiment, a magnifier feature can provide a detailed view of a celestial body while related information is displayed. Furthermore, in some embodiments, the invention can include two or more simultaneously displayed area representations, each having an associated displayed detailed or magnified view. Two magnified views, each associated with a portion of each area representation, can be used, for example, to compare details or portions of the two or more area representations. The invention may be implemented with many features in addition to those described herein. For example, a search function can be provided which extends beyond a single map or area representation. Thus, a map associated with the desired information can be located. Also, many variations on navigation and information drilling can be provided. For example, a first mouse click at a location may provide item information and a double mouse click may activate a link to a URL. Further, mouse clicking may activate a multimedia display (song or video clip). For example, mouse clicking a billboard can provide multimedia advertising. Multimedia and other engaging presentations can be utilized in conjunction with the interactive area representation of the invention. For example, such presentations can include broadband streaming audio and video, animation, film clips, etc. Such presentations can be simply presented to a user or can be user-interactive. The presentations can be activated by various occurrences, such as the user clicking on a feature in a magnified or unmagnified view, or by simply moving a magnifier to a certain portion of an area representation or over or near a particular feature. Alternatively, such presentations can be randomly generated or otherwise generated independently of user input. BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated in the figures of the accompanying drawings which are meant to be exemplary and not limiting, in which like references are intended to refer to like or corresponding structure or functions, and in which: FIG. 1 is a block diagram of a system according to the invention for electronically presenting inventive interactive maps and information; FIG. 2 is text file that includes coordinates on a magnified view of a map; FIG. 3 illustrates an unmagnified view of the map with a magnifier at a given location on the map; FIG. 4 illustrates a magnified view corresponding to the portion of the map within the magnifier shown in FIG. 3 ; and FIGS. 5-9 illustrate electronic presentations of maps, item information and magnified map portions in accordance with the invention. DESCRIPTION OF PREFERRED EMBODIMENTS Maps (and other area representations, as discussed above) are provided in accordance with the preferred embodiment of the invention over the Internet for electronic display using appropriate devices such as a personal computer (including equivalent devices for the purposes of this invention), PDA, any type of web enabled TV, etc. However, maps (and other area representations) may be provided in accordance with the invention on stand-alone devices not connected in or to a network, such as personal computers, or devices connected to an intranet, LAN, WAN, etc. In addition, broadband or other high speed Internet access can be utilized. While the discussion below focuses on maps and an Internet implementation of the invention, the invention is not limited to maps or an Internet implementation, and those of skill in the related technology field(s) can provide other implementations of the invention from the disclosure herein without undue experimentation. For example, the invention can be implemented using systems such as or including kiosks, cellular telephones, personal digital assistants (PDAs) or other portable or handheld computers, notebook or laptop computers, or other computerized systems or devices. In some embodiments, the invention is implemented utilizing a kiosk which can be completely stand-alone and include all necessary databases as described herein, or a kiosk which accesses remote databases, for example, through wireless communications. A kiosk according to some embodiments can include a touch sensitive screen for user interface, which can be, for example, stylus-based or finger touch-based, as known in the art. In addition, the invention can be practiced using cellular telephones, which can, for example, have wired or wireless Internet access, and which can have navigational or directional controls enabling user interface with and selection from a display. Furthermore, the invention can be implemented utilizing storage media including disks, CD-ROM, DVD or other storage media and systems. In some embodiments, the invention is used for educational or instructional purposes, such as to educate as to geography. According to other embodiments, the invention may be implemented using an interactive television system. Such a system may include, for example, one or more user computers or terminals, a head end content distribution center comprising or in communication with at least one computer and one or more databases containing information such as map location, actual location text and graphics information. A set top box, such as those manufactured by Scientific Atlanta and known to those of skill in the art, is one example of a user computer or terminal for two-way interfacing with the head end. The set top box can itself be a computer, or can communicate with remote computers, such as computers at the head end distribution center. A display device connected to the user terminal can be configured to present the map and other areas which can contain graphics or text. In some embodiments, a television remote control device having screen navigational capability, such as can be provided, for example, by directional arrow buttons and other buttons or operational features on the device, may be used to navigate or provide input or selection in accordance with the present invention. The remote control device can be used to navigate between, select, provide a query, or provide input associated with map locations, item information, or other text or graphics information. Furthermore, the remote control device can be used to position or dynamically move a position indicator, such as a magnifier, to or between positions on the map. The remote control device can be used with interactive television to perform operations similar or identical to those that can be performed in other embodiments of the invention with a mouse or other device, as is described herein. Referring to FIG. 1 , a system 10 implementing the invention includes a server 12 that communicates with user devices 14 over a network 16 . Graphic information from which map displays are provided is stored in a graphic files database 18 , e.g., in graphic files such as compressed GIF files, and text information from which item information and advertising are provided are stored in a text database 20 , e.g., in text files. A computer 22 may be used to provide and edit graphic and text files for databases 18 and 20 . A library 24 of graphic files may be provided, from which graphic files are stored in database 18 either in edited or unedited form. In the preferred embodiment, the network 16 is the Internet, the server 12 is a web server, and the user devices 14 are devices which support a web browser and are capable of accessing web sites over the Internet, such as personal computers. Using standard web-browsing software, a user device 14 may connect to the web server 12 using any device capable of supporting a web browser (including, but not limited to, personal computers, PDAs such as Palm Pilots, and pocket PCs and internet-enabled cellular phones, etc.). In one embodiment, the web server 12 , using standard web-serving software, sends a Shockwave executable application and relevant graphics and text files to the user's device 14 , which in this embodiment includes a web browser with a Shockwave plug-in that is capable of executing the Shockwave application. The use and operation of the Shockwave executable application is known by those of skill in the related art. The graphics and text files in databases 18 and 20 are maintained by conventional graphics and text editing software in computer 22 . Using this software, the graphics and text files can be updated, and individual listings can be deleted and added as necessary. The library of graphical files can store images of buildings, streets, parks, etc., and these can be used in known manner to construct map graphics files stored in a compressed format such as GIF in graphic files database 18 . The text file contains: categories and lists of public and private entities; each entity's address, phone number, fax number, and web site hyperlink; and each entity's coordinates relative to the GIF file of the magnified map ( FIG. 2 ). In this embodiment, the web browser on a personal computer and the Shockwave executable application display, an “unmagnified view” 30 of the concerned map ( FIG. 3 ), and a section of a “magnified view” 50 ( FIG. 4 ), from two GIF files. Accordingly, there are two maps: an unmagnified map ( FIG. 3 ), and a magnified map, of which a portion is shown in a circular window 55 ( FIG. 4 ). In the illustrated embodiment, the magnified view is four times larger than the unmagnified view. (Any suitable magnification can be used.) Further, although there are other ways of importing graphics from the server, in the preferred embodiment graphics remain external to the program file and the application imports a reference to it. A magnified view, as used herein, is intended to mean any presentation or view that appears magnified with respect to an unmagnified view. For example, in some embodiments, a magnified view presents features, images, text, or other information as larger versions of the features, images, text, or other information presented in an unmagnified view. In some embodiments, a magnified view can include only larger “versions” of features, etc., whereas in other embodiments, a magnified view can include larger “versions” of features, etc., as well as additional detail not included in an associated unmagnified view. Furthermore, in some embodiments of the invention, users can select features, etc. from the magnified view to obtain information associated with such features. It should be kept in mind that the invention also contemplates detailed views other than magnified views, which detailed views are more detailed than associated less detailed views. In varying embodiments of the invention, different levels of magnification in magnified views can be used. Furthermore, in different embodiments, the level of magnification can be set or scaled automatically depending on the unmagnified view or some other parameter, or can be selected or specified by a user in accordance with a level of detail, magnification, or scaling which is necessary, desired, or most convenient for the user. In the preferred embodiment, the software executed by system 10 was developed in Macromedia director, but it could be implemented in any programming language such as C++ or Java. The system could also be implemented directly in hardware such as in a handheld image/map navigation device. Director utilizes a second quadrant coordinate scheme. Under this scheme, the origin is at the top left corner of the stage (i.e., the presentation window or screen view), x values go from left to right, and y values go from top to bottom, all coordinates are calculated relative to the stage, and the units are screen pixels. (Any x values left of the stage and any y values above the stage are negative values. For example, if a graphic is located to x: 100/y: 100, the graphic will be placed 100 pixels to the right of the left edge of the stage, and 100 pixels down from the top edge of the stage. If the location of a graphic is set to x: −50/y: −50, the graphic will be placed 50 pixels to left of the left edge of the stage, and 50 pixels above the top edge of the stage.) Since only what is placed within the dimensions of the stage will be displayed, if part or all of a graphic is placed off the stage, it does not show when the program is running. (Moreover, because the large map is much bigger than the stage in the preferred embodiment, a portion can only be seen at any time within a circular window or mask.) The coordinates in the text file ( FIG. 2 ) reference the magnified view 50 . The first two numbers are the “x” and “y” coordinates for the graphic on the map; the third and fourth numbers are their widths and height. The Shockwave application responds to changes in the location of the position indicator on the unmagnified view by displaying the new corresponding area of the magnified view within the circular mask, and by searching the text file ( FIG. 2 ) to retrieve whatever listing is associated with that new location (using the coordinates on the magnified view). Moreover, when a particular listing is selected, the Shockwave application retrieves further information about the listing and displays that information to the user. Concurrently, the Shockwave application retrieves the coordinates of the selected listing on the unmagnified view (e.g., by referencing the magnified view's coordinates and by dividing the magnified view's coordinates by, in this embodiment, four), and moves the position indicator to the corresponding location on the unmagnified view. With reference to FIG. 5 , a part of the magnified view 50 obtained from one GIF file is displayed which corresponds to the area on, at, near, adjacent to or surrounding the coordinates of the magnifier 65 . In the disclosed embodiment, the Shockwave application displays from another GIF file the entire unmagnified view 30 of the concerned geographic area (e.g., the city's map) on the left side 40 of a browser window. In addition, the Shockwave application displays category listings in a text area 90 . The magnifier 65 highlights a geographic area on the unmagnified view, which in this embodiment is a circle. On the right side of the browser window, the Shockwave application displays the part of the magnified view 50 within a circular window 55 that corresponds to the area circumscribed by the magnifier on the unmagnified map 30 . The Shockwave application also displays on the bottom portion 90 of the browser window a list of the categories corresponding to categories listed in the text file. In one embodiment, the magnified view 50 changes in accordance with movement of the position indicator's movement or the dragging of the magnifier 65 , i.e., the portion of the magnified view 50 is moved relative to the circular window or mask 55 responsive to the position of the magnifier 65 . This is accomplished using scripts. One script is attached to the magnifier and responds when the user clicks the mouse down while the cursor is positioned over the magnifier. The script performs three tasks in response to a mouse click. One, the script sets a variable to true indicating that the mouse is clicked down. Two, it sets a variable -mX- indicating the horizontal distance from the cursor to the x coordinate of the center of the magnifier (x coordinate of the center of the magnifier minus the x coordinate of the cursor). Three, it sets a variable -mY- indicating the vertical distance from the cursor to the y coordinate of the center of the magnifier (the y coordinate of the center of the magnifier minus the y coordinate of the cursor). In addition, a score script tells the program to loop over and over in the current frame of the score (i.e., the timeline in Director). In each iteration of a loop, the script checks the true/false variable indicating whether the user has clicked down on the magnifier. If the true/false variable is false, the script does nothing. If it is true, the script performs the following tasks: it sets the location of the center of the magnifier to the location of the mouse cursor minus mX and mY. The script then sets a variable to the distance of the center of the magnifier from the left edge of the small map and sets another variable to the distance of the center of the magnifier from the top edge of the small map. It then multiplies these variables by four (in this embodiment) to calculate the equivalent distances for the magnified view and sets the top left corner of the map of the magnified view to the center of the large circular window 55 minus the equivalent horizontal and vertical distances. (For example, if the magnifier is located 300 pixels from the left edge of the small map and is located 250 pixels from the top edge of the small map, the equivalent distances on the magnified view would be calculated as 1200 and 1000 respectively. Since in the preferred embodiment, the center of the circular magnified view's window (or mask) is located x: 600/y: 150, the top left corner of the magnified view map would be set at x: 600-1200/y: 150-1000, or x: −600/y: −850.) By looping very quickly and running this score script over and over again, the program will repeat the above calculation hundreds of times if the user's mouse button is clicked down for a period of time. Accordingly, the magnifier 65 and the magnified view within windows 55 snap from one discreet point to another very quickly which gives the impression of sliding movement. Furthermore, if the user clicks anywhere on the unmagnified view outside of the magnifier 65 , e.g., at the location of the position indicator 70 in FIG. 5 , the magnifier will snap to the location of the user's click ( FIG. 6 ), and the position of the magnified view within the large, circular window 55 will be adjusted accordingly. The position indicator 70 will then appear in the magnifier, as shown in FIG. 6 . The system 10 also displays text associated with the various images (e.g., buildings) on the unmagnified and magnified views by using the position indicator's coordinates. Regions of the unmagnified view are indirectly tagged to specific text (vis-á-vis the magnified view's coordinates which are directly tagged to the text) which appear when the cursor enters these regions ( FIG. 2 ). For example, a region of the unmagnified view bounded by the coordinates 329 , 111 , 24 , 11 (using the magnified view's coordinates 1314 , 444 , 95 , 45 and dividing by four) is associated with the item information pertaining to the Burnett Group. Thus, whenever the position indicator is at or near this area on the unmagnified view, the item information associated with that region is retrieved, by simple index look-up or other text retrieval method. Other region shapes such as circles are also possible. The magnifier 65 used in the preferred embodiment is circular in shape and resembles a conventional magnifying glass. In the alternative embodiments, it could assume any shape that enables the user to identify a part of the map. Furthermore, in the preferred embodiment the user employs a mouse to move the magnifier by moving the cursor over the magnifier, holding down the mouse button, and moving the mouse to drag the magnifier, or by pointing and clicking at a desired location. Alternative embodiments include the use of any device capable of moving the position indicator, such as keypad, touch device, digitizer or touch screen, for example. For example, in response to a mouse click with the position indicator 70 located as shown in FIG. 5 , the system 10 activates a mouse “point and click” operation and provides the display shown in FIG. 6 . In response to a mouse “click and hold” mouse operation with the position indicator 70 located within the magnifier 65 in FIG. 6 activates a mouse “drag and drop” operation with which the magnifier 65 ( FIG. 6 ) the system 10 can be dragged and dropped to the position shown in FIG. 7 . In the preferred embodiments, the magnifier 65 is implemented by two sprites: one is a yellow circle which gives it visual definition, the other is a circular bitmap. The circular bitmap is given an ink effect called AddPin which adds the pixel colors of the circle to the pixel colors of the area of the map on which it lies. Accordingly, the resulting pixel colors are brighter than the colors of the map. When the user clicks down within or on the yellow circle, two variables are set to the horizontal and vertical distances between the horizontal and vertical coordinates of the mouse location and the horizontal and vertical coordinates of the top-left corner of the bounding box for the yellow circle. Another variable is set to true indicating that the magnifier has been clicked down on. Whenever the mouse is released, this variable is set to false. While the program is running, this variable is constantly checked. While the variable is true, the magnifier is moved to the horizontal and vertical coordinates of the mouse minus the two variables mentioned above. This ensures that the magnifier stays in place regardless of where the user clicks within it, rather than snapping to the location of the user's click. If the user clicks the position indicator on any part of the map outside the circle, the magnifier is moved with its center at the position of the position indicator. Once the user moves the magnifier 65 , the Shockwave application displays item information 160 relating to the new location in the item information portion which corresponds to the new position of the magnifier 65 . ( FIG. 6 .) In addition, the area in the magnified view that corresponds to the area indicated by the magnifier is presented in the magnified view 50 . Furthermore, the section 50 of the magnified view that is displayed is proportional to the area under the magnifier based on the ratio of areas of the maps (e.g., four to one). Accordingly, whenever the user browses a neighborhood by moving the position indicator relative to the map, the Shockwave application displays the item information and magnified image associated with the magnifier's new coordinates, either per a “point and click” or a “drag and drop” operation as described above. For example, if the user moves the magnifier to the Burnett Group building 150 , the item information associated with the Burnett Group will appear in the item information portion at the bottom of the display 160 and a magnified image of the Burnett Group's building will appear in right side of the display 185 within the circular mask. ( FIG. 6 .) Furthermore, the user may connect to the Burnett Group's web site by clicking on the web site link 170 in either the item information portion or on the building in the magnified view of the Burnett Group 185 . In response, the user device opens a new browser window and displays the web page provided by the server at the Burnett Group web site. In one embodiment, moving objects 200 (e.g., a hot air balloon and blimp) appear in the unmagnified view 30 ( FIG. 6 ) and in the magnified view 50 . ( FIGS. 7 and 8 ) as they traverse the map 30 . For example, a hot air balloon 200 is shown under the magnifier in the unmagnified view 30 in FIGS. 7 and 8 and in a magnified map portion 50 in FIGS. 7 and 8 . The objects may display messages to the user and/or include advertisements. The moving objects can include images of modes of transportation (e.g., planes, hot air balloons, cars, etc.), people, animals (e.g. birds) or objects (e.g. baseball hit outside of stadium). In one embodiment, algorithms are employed to generate the coordinates of the paths that the moving objects 200 (such as the balloon and blimp) are programmed to follow on the maps. The graphics for these objects are separate sprites and their animation is handled by the score script. Each object has two separate lists of points, one defining a path on the unmagnified view and one defining a path on the magnified view. The script that handles the movement of the magnifier can also handle animation of the balloon and blimp. There are two lists of points for each moving object: one each for the smaller and larger versions. For two moving objects (a balloon and a blimp), there are four lists of points: one for the small balloon, one for the large balloon, one for the small blimp, and one for the large blimp. Each list of points, calculated beforehand, is passed to the score script. Starting with an initial index number which is incremented after each repetition of the score script's loop, points are retrieved from each of the four lists using the index number. The points are x/y pairs and they tell the program where to put the graphics for the balloons and blimps. For example, in the first iteration of the loop, the index number is set to 1. The script gets the number 1 point for each of the lists, and sets the position of the graphics to those points. In the next iteration, the index number is 2. The script gets the second set of points from the lists, and sets the positions of the graphics to those points, etc. There may be a very slight delay between the passing of the smaller and the passing of the larger sprites within their respective circular areas. This can be caused by a slight lack of precision when using the scaling factor in the algorithm which generates the list of animation points. The user may also choose to browse a neighborhood by selecting a category listing from the item information portion. ( FIG. 7 .) For example, when the user clicks on a category heading 310 , the executable Shockwave application searches the text file for business listings under the category (e.g., “city agencies”), and displays the listings 410 ( FIG. 8 ) in the item information portion. The user may then move the position indicator 70 to a particular listing such as “City Stationers” 420 and click. The Shockwave executable application then searches the text database for “City Stationers” and finds and displays item information associated with the listing such as its address, phone number, fax number, and a web site link 510 ( FIG. 9 ). The region on the magnified view 50 associated with the text string is determined by matching the selected string with strings in the region list. When a match is found, then a center point associated with the region is either computed (e.g. by finding the center of a rectangular region), or a stored center point is retrieved and the content in the magnified view is updated. In addition, the Shockwave executable application determines the coordinates of the selected listing on the unmagnified view 30 (by dividing the magnified view's coordinates by four), and positions the position indicator over the City Stationers building in the magnifier 65 . The user may then connect to the City Stationer's web site by clicking the position indicator 70 ( FIG. 9 ) on the web site link 540 in the item information portion, or by clicking the position indicator 70 on the City Stationers building graphic 530 in the magnified view 50 . (Two position indicators 70 are shown in FIG. 9 for purposes of illustration.) In the disclosed embodiment, advertising is presented in the form of stationary billboards 188 and moving objects 200 ( FIG. 6 ). In alternative embodiments, advertising can appear in any form that could be associated with a bird's eye view of a region. Advertisements could be presented on moving or stationary subway cars, taxis, planes, boats, etc. While airborne moving objects such as balloon 200 and blimp 200 can follow any path, ground vehicles will move through streets according to any desired path, etc. Advertising can be presented as discussed above and fees can be charged as discussed above. Animated images can be associated with particular locations or items on an area representation or view, or can be not associated with any presented location or item. In some embodiments, animated images are selected based upon or to appeal to an anticipated set of users of an area representation. Use of a Shockwave application on user devices distributes processing requirements so that a large number of users can be served from a modestly-powered web site. In the alternative embodiments, image files may contain maps of any region. For example, the user may be able to view maps of any geographic area of the world, e.g., cities, rural regions, bodies of water, and even areas in space, etc. Moreover, the text file may contain any information associated with an item on a map. For example, alternative implementations may include additional categories such as parks, hospitals, famous landmarks, subway stops, etc. Furthermore, the categorical directory could employ advertising and various multi-media possibilities such as animation, music, sound, and voice-overs. Furthermore, in an alternative implementation, a database could replace the text file described above and serve as a source of listings and map's coordinates. In this alternative implementation, the Shockwave application would query the serving machine in order to obtain information. The invention is also not limited to a particular means of data transmission necessary to move files from a server to a user's device—the method could involve wired or wireless Internet access, cable, phone, satellite, or DSL. While the invention has been described and illustrated in connection with preferred embodiments, many variations and modifications as will be evident to those skilled in this art may be made without departing from the spirit and scope of the invention. As mentioned, the invention has application to many variations of maps, and to area representations of many things in addition to maps. The invention is thus not to be limited to the precise details of methodology, construction or application set forth above as such variations, modification are and applications intended to be included within the scope of the invention.

The present invention provides computerized systems and methods for providing electronically presented interactive area representation, such as a map, and information associated therewith. A user can select text, imagery, or other information presented on the map and associated with one or more items or locations, causing presentation of information relating to the associated one or more items or locations, such as appropriate contact information or a hyperlink to an appropriate Web site. Additionally or alternatively, a user can input or select, based on a query or otherwise, information relating to one or more items or locations associated with text, imagery, or other information presented on the map, causing presentation of an indication of one or more locations of the associated text, imagery, or other information on the map. A magnifier feature allowing internal navigation within the map can be provided. Additionally, animated images can appear to move over the map.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application No. 60/663556 filed Mar. 18, 2005. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH [0002] The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Grant No. H133E003001 awarded by the U.S. Department of Education. SEQUENCE LISTING OR PROGRAM [0003] Not applicable BACKGROUND—FIELD OF THE INVENTION [0004] The present invention relates to improvements in a knee orthosis (KO) used for supporting a person's knee along with extensions for supporting the user's hip and ankle. The orthosis of the present invention assists the user in extension and flexion of the user's hip, knee, and ankle while controlling sagittal, transverse, and/or coronal plane stiffnesses and deflections. BACKGROUND—DISCUSSION OF PRIOR ART [0005] Knee Orthoses are currently used to support the knee when there is muscle weakness, bone deformity, joint deformity, joint damage, tendon damage, ligament damage, and/or whenever the loads and moments applied are higher than the person's physiology can handle. [0006] Knee orthoses are commonly used in combination with ankle-foot orthoses to make knee-ankle foot orthoses (KAFO's), and hip orthoses to make Hip-knee-ankle-foot orthoses (HKAFO's). [0007] The disadvantages of current KO's are that they cannot apply a moment across the knee that is biomechanically suitable. The human body uses its muscles to apply a non-linear moment across the knee for a full range of motion of the knee. [0008] Current knee joints lock the knee entirely, lock the knee for all of stance phase of the gait cycle, or allow it to flex during stance phase, but not during swing phase. The normal human has high stiffness knee flexion during the load response part of stance phase, and low stiffness knee flexion during swing phase. No current knee orthoses provide these stiffness and range of motion properties. [0009] The stiffness of an individual' knee varies with their weight, height, activity level, loads carried, strength and other factors. This brace allows an orthosis with a particular stiffness to be fabricated for a particular individual or class of individuals. [0010] Current braces have very rigid flexion stops and/or extension stops, which cause sudden decelerations. These decelerations over time can damage a patient's knee and hip joints. Slower decelerations such as those applied by a normal person's muscles may be better. [0011] U.S. patent application Ser. No. 11/111,973 by Reynolds et al shows a technology for controlling the ankle joint using segments on at least one strut. [0012] There is a need for a knee orthosis, which applies a controlled non-linear stiffness across the knee in both flexion and extension that is similar to the stiffness applied by a normal person's muscles during gait. This stiffness needs to be reduced for sitting and swing phase. SUMMARY [0013] The knee orthosis described in this application provides significantly enhanced performance compared to currently available knee orthoses. This orthoses has at least one strut, a thigh shell, a calf shell and at least one deflection limiter with gaps between the deflection limiter and the calf and thigh shell. DRAWINGS [0014] FIG. 1 is a perspective right-side view of a right leg knee orthosis constructed in accordance with the invention. The knee orthosis used for the left leg is a mirror image. [0015] FIG. 2 is a lateral side view of FIG. 1 . It shows a thigh shell, defection limiters, and the spacers between the deflection limiters. [0016] FIG. 3 is a view in detail of the portion indicated by the section line 3 - 3 in FIG. 2 . It shows the spacers between the deflection limiters, and the holes for a knee extension assist device, and a locking/unlocking linkage. [0017] FIG. 4 is a posterior perspective view of the knee orthosis with optional hip extension, optional Posterior Strut Ankle Foot Orthosis extension and optional Medial Lateral Strut Ankle Foot Orthosis extension. The orthoses used for the left leg are mirror images. NUMERALS IN DRAWINGS [0000] 7 Comfort Liner 10 Knee orthosis tab for attachment to ankle foot orthosis 11 Hole for Pin# 52 12 Knee hinge 13 Lock/Unlock Rod 14 Spacers 15 Extension assist 16 Thigh straps with hook and loop closure 17 Lock/unlock drive rod 18 Thigh shell 20 Hook and loop closure 22 Hook and loop closure 24 Hip joint 26 Pin to retain tab 62 27 Strut with slot for attachment to knee orthosis 28 Slot for attachment to Tab ( 10 ) on knee orthosis 30 Lock/unlock drive rod 32 Lock/unlock drive tube 34 Medial lateral strut AFO calf shell 36 AFO lateral support strut 38 Lock/unlock drive rod length adjustment 40 Lock/unlock drive rod length adjustment 42 Drive rod attachment to foot shell 44 Lateral ankle joint 46 Foot shell 48 Lock/unlock drive rod 50 Posterior strut AFO calf shell 52 Pin to hold knee orthosis tab in place 54 Rocker to change direction of drive rod 56 Lock/unlock drive rod connector 62 Tab for attachment to hip extension 63 Hole for Pin # 26 64 Hook and loop closure 66 Deflection limiters 67 Strut 68 Calf shell 70 Hip band DESCRIPTION OF THE INVENTION [0055] The present invention relates to a knee orthosis (“orthosis”) worn by a user on the user's leg or optionally on the user's hip and leg. The orthosis supports and assists users who have difficulty in standing and walking. Additionally, a user having no such difficulty can use the orthosis to assist their normal movement, which may assist the user's performance and endurance. [0056] FIG. 1 shows a knee orthosis constructed and arranged in accordance with the invention. It consists of a thigh shell 18 , which is securely attached to the wearer's thigh. It could be a generic shape or it may be custom made for a particular individual's leg. It could have anterior segments and/or posterior segments connecting the medial and lateral sides, and/or it could be spiral shaped and wrap around the thigh, and/or it could have straps with hook and loop closures and/or buckles or other attachments across the anterior sides 16 , 4 , and/or posterior straps, and/or encircling straps, and or no straps. [0057] Attached to the thigh shell on the medial and lateral sides are struts 67 (seen in the cross-section FIG. 3 ) which could consist of one piece or multiple struts. A single strut on only the medial or lateral side is also possible. The preferred embodiment has two struts on the medial and lateral side of the leg. [0058] The orientation of the struts 67 from the thigh shell 18 to the knee joints 12 can be set at an angle to the line between the center of the wearer's anatomical hip joint to the center of the wearer's anatomical knee joint. This in combination with the below knee struts 67 , and locked knee joints 12 allows the knee angle that the brace applies zero moment to the leg to be controlled. For example, if the knee joints 12 lock at 180 degrees and the above knee struts are oriented in 10 degrees of flexion to the hip to knee line, and the below knee struts 67 are oriented in 0 degrees of flexion to the knee to ankle line then the orthosis will apply zero moment at 10 degrees of knee flexion. This angle can be customized to the needs of the user. [0059] Below the thigh shell, a one or more rigid segments called deflection limiters 66 surround the struts 67 or are attached to the struts 67 . The deflection limiters 66 can be tapered, expanded, or parallel on the proximal and/or distal edges of the posterior and/or anterior sides to allow a different deflection or stiffness in flexion than in extension (tapering on the posterior side shown). Between the thigh shell 18 and the deflection limiters 66 , and between the deflection limiters 66 themselves are rigid spacers 14 which allow the struts 67 to bend in a very controlled manner. The height of the spacers 14 and the shape of the deflection limiters 66 controls when the deflection limiters touch each other and the calf shells 68 and thigh shells 18 as the struts bend. These spacers could be separate pieces or incorporated into the shape of the deflection limiters 66 . As strut 67 bends, the gaps controlled by the spacers 14 and the shape of the deflection limiters 66 progressively close. When the deflection limiters 66 touch each other or the thigh shell 18 or the calf shell 68 , they effectively shorten the unsupported length of strut 67 , increasing the stiffness of the knee orthosis. [0060] Attached to the strut 67 , below the deflection limiters 66 , are the knee joints 12 . This can be any type of knee joint such as a locking joint, a ratcheting lock joint, a stance-locking joint, range of motion-limited joint, and/or a free joint. The medial and lateral knee joints 12 may be of different types. In an additional configuration, both knee joints 12 can be removed allowing the strut to continue through this area and adding deflection limiters and spacers (if needed). In a further configuration, if only minimal support is needed, the medial knee joint 12 , deflection limiters 66 and strut 67 may be removed entirely. [0061] Below the knee joint 12 is another section of medial-lateral struts 67 with spacers 14 and deflection limiters 66 constructed in the same manner as above. The number of deflection limiters 66 and spacers 14 may vary as needed. [0062] Towards its distal end, the strut 67 is attached to a calf shell 68 . The calf shell 68 may be a generic shape or it may be custom made for a particular individual's leg. It could have anterior and/or posterior bars (not shown) connecting the medial and lateral sides, and/or it could be spiral shaped and wrap around the calf (not shown), and/or it could have straps with hook and loop closures 16 , 4 and/or buckles-across the anterior side, and/or posterior straps, and/or encircling straps, and/or it can be constructed so that when it mates with an AFO, the AFO helps hold it on the lower leg (shown in FIG. 1 , FIG. 2 , FIG. 3 , and FIG. 4 ). [0063] The orientation of the struts 67 from the calf shell 68 to the knee joint 12 can be set at an angle to the line between the center of the wearer's anatomical knee joint and the center of the anatomical ankle joint. This in combination with the strut 67 above the knee joints 12 allows the knee angle that the brace applies zero moment across the knee to be controlled. For example, if the knee joints 12 lock at 180 degrees and the above knee struts 67 are oriented in 0 degrees of flexion to the hip to knee line, and the below knee struts 67 are oriented in 10 degrees of flexion to the knee to ankle line, then the orthosis will apply zero moment at 10 degrees of knee flexion. This angle can be customized to the needs of the user. [0064] The gaps between the deflection limiters 66 themselves and between the calf shells 68 and thigh shells 18 and the deflection limiters 66 can be controlled by a variety of means such as through an integral step in the deflection limiters and the shells, through tapering or expanding the deflection limiters 66 or calf shells 68 and thigh shells 18 (shown in FIG. 2 ), and/or through the addition of rigid spacers 14 (as in FIG. 1 , FIG. 2 , FIG. 3 ., and FIG. 4 ), and by attaching the deflection limiters 66 directly to the strut 67 . [0065] FIG. 2 shows the lateral side view of the knee orthosis shown in FIG. 1 for use on the right leg. There is a comfort liner 63 on the inside of the thigh shell 18 and calf shell 68 to provide padding next to the wearer. [0066] FIG. 3 shows the cross-section of the knee orthosis at section line 3 - 3 . Visible are the struts 67 which each could consist of a single strut or multiple smaller struts, spacers 14 , lock unlock rods 16 which could be round or square, and the holes 15 through which the extension assist mechanism passes. A cross-section through the struts 67 above the knee joints 12 would be similar. [0067] Along the anterior side of each strut is an optional knee extension assist mechanism located in holes 15 . This consists of a bungee cord, spring, flexible rod or combination of similar devices that is attached to the deflection limiters or the thigh and calf shells and crosses the knee joint on its anterior side. When the joint is unlocked and the knee bends the device resists flexion. [0068] Along the posterior side of each strut is a lock/unlock rod 17 in a hole or channel. This can be used when a locking knee joint or stance control knee joint is used. This rod allows the knee brace to be unlocked during swing and locked during stance by the angle of the ankle (shown in FIG. 4 ) or by contact with the ground, or a foot switch, or a solenoid or other mechanism (not shown). If the direction of the lock/unlock rod 48 , 17 , 13 needs to be changed, a simple mechanism 54 such as a pivot can be used. The lock/unlock rod 13 can cross into the AFO adjacent to tab 10 . It engages automatically when the AFO is attached. It may also be unlocked by full knee extension. [0069] In an alternate configuration, some stance locking knee joints such as the Stance Phase Lock by Basko Healthcare do not require this lock/unlock rod 17 . In an alternate configuration, a knee joint can be locked and unlocked by a lever or other mechanism that is triggered by knee flexion and weight bearing [0070] In another embodiment, the length of the lock/unlock rod 48 , 13 , 17 and when it triggers can also be easily adjusted by a mechanism 38 , 40 which consists of a bar attached to the footshell of the AFO by connector 42 which slides on the drive rod when the ankle is rotated. This bar which will only move the lock/unlock rod 13 when it contacts blocks attached to the drive rod. Other similar mechanisms such as those found on bicycle brakes will also work. [0071] A stance locking knee joint can also be fabricated in this orthosis by using a freely rotating knee joint and a lock/unlock rod 17 made of a durable material such as metal. During plantarflexion of the ankle or some other locking signal, the rod pushes up and inserts into a slot or hole on the other side of the knee joint. This prevents rotation of the knee. If this hole is in a lock/unlock rod 17 that extends into the thigh shell, the knee joint 12 can be manually locked or unlocked by the wearer by lowering this lock/unlock rod 17 across the joint. [0072] A separate or connected lock/unlock rod 17 can also extend from the knee joint into the thigh shell allowing the knee to be manually locked, unlocked, or placed into automatic stance control mode by the wearer or an assistant. [0073] FIG. 4 is a posterior perspective view of the knee orthosis with optional hip extension, optional Posterior Strut Ankle Foot Orthosis extension and optional Medial Lateral Strut Ankle Foot Orthosis extension. [0074] FIG. 4 also shows the optional pins bolts, rivets, ball snaps, pip pins or other connector 52 , which attach the tabs 10 , 62 to the AFO and hip orthosis. The shape of the knee orthosis calf shell 68 can be made with a step on the distal surface with a matching step on the proximal ankle foot orthosis calf shell 50 to facilitate connection and enhance support between the AFO and the knee orthosis. [0075] At the bottom of the calf shell 88 are optional tabs 10 that allow the knee orthosis to be attached to an optional medial-laterally jointed AFO or posteriorly jointed AFO. [0076] At the top of the thigh shell 18 is an optional tab 62 that allows the knee orthosis to attach to an optional hip orthosis. [0077] The parts of a typical medial/laterally jointed AFO are the footshell 46 , the ankle joint 44 which could be a free joint, a dorsiflexion assist joint, a dorsiflexion stop joint, a plantarflexion stop joint or a locked joint. Medial lateral struts 36 take the loads in the AFO. It has slots 28 for accepting tab 10 . It has a lock/unlock actuator rod 30 in a tube 32 and an ankle foot orthosis calf shell 34 . [0078] The parts of a posterior strut AFO are a foot shell 46 , an AFO calf shell 50 , and a drive rod 48 , 13 attached to the footshell with a connector 56 . [0079] The parts of a typical hip orthosis are a hip band 70 a strap 20 with a buckle, connector or hook and loop closure 22 . A hip joint 24 and a strut 27 with a slot to accept tab 62 . [0080] The same techniques used for adjusting flexion/extension stiffness described previously in this specification, such as adjusting the size of the spacers 14 , the size or number of struts 67 , or the shape of the deflection limiters 66 , can be used to control medial and lateral knee stiffness and deflection in the transverse plane, as well as torsion in the coronal plane. This can be useful for compensating for knee and ankle varus/valgus. [0081] The knee orthosis can be fabricated using various materials such as a fibrous material such as carbon fiber or fiberglass impregnated or pultruded with thermoset resin such as acrylic or epoxy, or out of metals such as aluminum or stainless steel. Additionally, it can be made using thermoplastic materials such as polyethylene and polypropylene. Preferred Embodiment [0082] The preferred embodiment will depend on a particular patients needs. This knee orthosis provides a convenient selection of devices and characteristics to allow it to be tailored to allow a wide variety of patients the ability walk with an improved gait. [0083] Many patients with severe calf and thigh weakness would use a configuration comprising of a posterior strut AFO connected to the knee orthosis. The knee orthosis strut 67 would be oriented 5 degrees forward of the line between the wearer's anatomical knee joint and hip joint, and 5 degrees forward of the line between the anatomical knee and ankle joints. This would make the knee moment equal to zero at a knee flexion angle of 10 degrees. There would be a knee extension assist consisting of elastic material. The knee joints 12 would be locking/unlocking knee joints with a lock/unlock rod 48 , 13 attached to the foot shell 46 of a posterior strut AFO connected through a pivot 54 . The orthosis knee joint would be located near or slightly posterior to the anatomical knee joint. OPERATION OF THE INVENTION [0084] The knee orthosis is attached to or around the lower leg of the wearer. First, the AFO is attached to the foot using straps if necessary. The shoe is then placed over the footshell 46 . It is also possible to design the footshell 46 to fit over the shoe or not require a shoe at all. [0085] The knee joints 12 are manually unlocked by moving the lock/unlock rod 17 inside the thigh shell 18 and the thigh shell 18 is placed around the wearers thigh and tab 10 is placed in slot 28 . Straps 16 are then secured. If used, the hip orthosis is placed around the waist and tab 62 is attached to strut 27 . Strap 20 is then secured. The wearer then extends their legs, manually locks the knee joints 12 , stands up and walks. Sometimes additional assistive aids such as canes or walkers are also needed for ambulation. To remove the orthosis, the process is reversed. [0086] In operation, almost any kind of knee stiffness curve can be predictably obtained using this invention. The size of the struts 67 determines the initial stiffness. The size of the spacers 14 and the shape of the deflection limiters 66 and calf shell 68 and thigh shells 18 determine how fast the stiffness increases. As the struts 67 bend, the gaps between the deflection limiters 66 progressively close and eventually touch each other or the calf shells 68 and thigh shells 18 . This prevents further bending and the effective length of the struts 67 are shortened, increasing their stiffness. The width of the gaps is measured from the struts' 67 neutral axis and the gap height in an anterior/posterior manner determines how fast the stiffness increases. The smaller the gaps on the anterior side of the strut, the faster the stiffness in knee extension increases. The smaller the gaps on the posterior side, the faster the knee flexion stiffness increases. [0087] The stiffer the extension assist material 15 , the higher the extension assist force when the joint is unlocked. [0088] The desired initial stiffness of the knee orthosis can be determined by dividing the normal knee moment by the normal knee angle at every point in the gait cycle. This desired value can be modified depending on the wearer's strength, and needs of the wearer. Standard beam bending equations applied to the struts 67 can be used to predict the initial stiffness of the knee orthosis in the sagittal plane. As each gap closes, the new stiffness can be calculated with the same equations by progressively shortening the effective length of the struts 67 by the height of deflection limiters 66 with their gaps closed. The maximum deflection can be calculated through basic geometrical formulas. [0089] During gait, when the ankle plantarflexes under body weight, the knee is unstable and needs to be supported. When the ankle dorsiflexes, the ground reaction forces extend the knee joint so it does not need to be prevented from flexion. So a linkage across the ankle can be used to lock and unlock a knee joint 12 . [0090] In another embodiment, during gait, a ground reaction force corresponding to the weight of the wearer applied posterior to the ankle joint creates a flexion moment on the knee. So when a pushrod near the heel is compressed by body weight, it can trigger a lock at the knee. When the heel lifts up such as during push off, the spring-loaded pushrod returns to its original position and the knee is unlocked for swing through. [0091] During the load response part of the gait cycle, a normal human flexes their knee. This brace allows the knee to be supportably flexed with a controlled stiffness during load response when the knee joint 12 is locked. [0092] To sit down the wearer puts their knee into a neutral angle, pulls on the lock/unlock rod 17 in the thigh shell 18 to unlock the knee joint 12 . Then the wearer sits down. The orthosis allows the knee to flex past 90 degrees. To stand up, the process is reversed. Description and Operation of Alternative Embodiments [0093] An alternate configuration, to allow a variable stiffness curve, for a patient with a changing clinical picture, for changing terrain conditions, for more accurate initial stiffness setting, or many other reasons, consists of replacing some or all of the rigid spacers 14 with elastic spacers 14 made out of a material such as rubber and adding a device to compress the elastic spacers 14 such as a cam located medially or laterally to the strut (not shown) or a mechanism as simple as two locknuts on a threaded rod inserted into holes (not shown) fabricated in the deflection limiters 66 and the thigh shell 18 and calf shell 68 . The holes would be located equidistant on the anterior and posterior sides of the strut. When the locknuts are turned in opposite directions on the threaded rod (or the cam rotated), the deflection limiters 66 and therefore the elastic spacers 14 are placed under compression, reducing the gaps between the deflection limiters 66 and between the thigh shells 18 and calf shells 68 thereby stiffening the knee orthosis. This configuration allows quick and simple brace stiffness modification. [0094] Another alternative embodiment of this knee orthosis is where the deflection limiters 66 are two separate rectangular blocks attached solely to the anterior and posterior sides of the struts rather than a single piece that surrounds the strut as shown in FIG. 1 . These rectangular blocks would work in the same as the previously described deflection limiters 66 . The calf shell 50 and foot shell 52 would be similar to those previous described. CONCLUSION, RAMIFICATIONS, AND SCOPE OF INVENTION [0095] Thus the reader will see that the knee orthosis which allows controlled non-linear knee stiffness in both flexion and extension comprising of deflection limiters 66 attached and/or surrounding a strut 67 which is attached to a thigh shell 18 and a calf shell 68 , provides significant improvements in the ability to fit a particular patient's knee stiffness needs. [0096] While principles of the invention are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure and claims.

A knee orthosis comprising of at least one deflection limiter ( 66 ) separated by gaps ( 10 ) on one or more struts ( 67 ), which are attached to a thigh shell ( 18 ) and a calf shell ( 68 ). The stiffness of the brace can easily be controlled in sagittal, transverse, and coronal planes whereby a person may obtain improved gait.

FIELD OF THE INVENTION [0001] This invention relates to internal combustion engines, including but not limited to recirculation of crankcase gases into the intake system of an engine. BACKGROUND [0002] The present invention relates to a breather system for a crankcase of an internal combustion engine of the type which separates oil drops or mist from blow-by gases. The blow-by gases are routed to the intake air line of an engine to eliminate the discharge of combustion gases into the environment. Separated oil is routed back to the oil pan. [0003] Ideally, the pressure within an internal combustion engine crankcase should be maintained at a level equal to or slightly less than atmospheric pressure to prevent external oil leakage through the various gasketed joints, such as that between the valve cover and the cylinder head. Combustion gases are generated during the operation of an internal combustion engine. A small amount of these gases leaks past the piston seals, valve stems seals, and turbochargers of the internal combustion engine. Because of the “blow-by” gases, the crankcase pressure will inherently rise, promoting leakage of oil from the crankcase. These gases, commonly referred to in the art as “blow-by” gases, need to be released. [0004] Environmental considerations suggest that the blow-by gases in the crankcase be vented back to the combustion chamber rather than being released to the atmosphere. Accordingly, it is known to scavenge the crankcase of blow-by gases by connecting the crankcase to the engine air intake. [0005] Blow-by gases that are released from the crankcase carry combustion by-products and oil mist caused by splashing of the engine's moving components within the crankcase and the oil pan. It is known to substantially remove the oil mist from the blow-by gas prior to introduction into the intake air system. An apparatus that removes oil mist from blow-by gases is commonly referred to as a “breather.” Known breathers include breathers that include a stack of conical disks that spin at a high speed to fling heavier oil against a wall of the breather and allow gas to pass though the breather. Centrifuge type separators are disclosed for example in U.S. Pat. Nos. 7,235,177 and 6,139,595. Other types of breathers include filters such as described in U.S. Pat. Nos. 6,478,019, 6,354,283; 6,530,969; 5,113,836; swirl chambers or cyclone separators, such as described in U.S. Pat. No. 6,860,915; 5,239,972; or impactors, such as described in U.S. Pat. Nos. 7,258,111; 7,238,216 5,024,203. Each type of breather has advantages and limitations. [0006] The present inventor has recognized that it would be desirable to provide a breather system that is more economical to produce and more effective in operation than existing breather systems. SUMMARY [0007] An exemplary embodiment of the invention provides a breather system for a crankcase of an internal combustion engine. The breather system includes a gas compressor having a compressor inlet and a compressor outlet. The gas compressor is configured to elevate the pressure of blow-by gas received into the inlet and to discharge elevated pressure gas from the compressor outlet. An inlet conduit is arranged to connect the crankcase to the compressor inlet. At least one gas-oil separator includes a gas inlet for receiving the elevated pressure gas from the compressor, an oil outlet for discharging oil separated from the elevated pressure gas, and a gas outlet for discharging a gas having a reduced oil content. The at least one outlet conduit connects the compressor outlet to the gas inlet. [0008] The at least one gas-oil separator can comprise a swirl chamber separator in series with an impact separator. The swirl chamber separator and the impact separator can be cast as a unitary housing. The oil outlet can be flow-connected to return the separated oil to the crankcase. [0009] According to an exemplary embodiment, the gas outlet is flow connected to an air intake for the engine to re-circulate the gas discharged from the at least one gas-oil separator. [0010] According to another aspect of the disclosed embodiment, the at least one gas-oil separator includes a gas outlet and a bypass conduit flow connected between the gas outlet and the compressor inlet. [0011] The compressor can be a piston pump type of compressor or other known type of compressor. [0012] The disclosed embodiment provides a method for separating oil from crankcase gas from an internal combustion engine, including the steps of: [0013] receiving crankcase gas outside of the crankcase and into a compressor; [0014] pressurizing the crankcase gas using the compressor; [0015] channeling the pressurized crankcase gas into a gas-oil separator; [0016] separating oil from the crankcase gas in the gas-oil separator; and [0017] returning the separated oil from the gas-oil separator to the crankcase. [0018] The method can also include the step of directing crankcase gas from the gas-oil separator to a combustion air intake of the engine. [0019] The method can also include the step of: if the capacity of the compressor exceeds the crankcase gas production, directing gas flow from the gas-oil separator to the compressor. [0020] Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, and from the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING [0021] FIG. 1 is a schematic diagram of a breather system of the present invention. DETAILED DESCRIPTION [0022] While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. [0023] FIG. 1 is a schematic diagram that illustrates an embodiment of an engine breather system 10 according to the present invention. The system 10 is associated with an engine 20 which could be a diesel engine, such as a diesel engine for a long haul truck. The diesel engine can be normally aspirated or turbocharged. The engine 20 includes a crankcase 22 having an upper engine internal volume 23 partly defined by a valve cover 24 . The upper engine internal volume is generally in fluid communication with all the blow-by gases within the crankcase. [0024] The system 10 includes a gas compressor or pump 26 that includes a piston or a rotary impeller (not shown) or other fluid actuating device that can be belt driven, gear driven or otherwise driven by the engine 20 . Alternately the compressor could be driven by another power source. A number of compressor or pump types can be used, in addition to the standard piston pump, such as a gear pump, a gear-rotor pump, a vane pump, a rotary screw pump, or a diaphragm pump. According to one embodiment, the compressor would be rated at less than 50 PSI and to maintain a relatively small size, would be capable of being driven at speeds up to 10,000 RPM. A typical maximum bow-by gas flow rate for the compressor is 700 CFH (ft 3 /hour). [0025] The gas compressor 26 includes an inlet 26 a that is in fluid communication via a conduit 28 with the internal volume 23 by a connection to the valve cover 24 . An outlet 26 b of the compressor is in fluid communication with an inlet 50 a of a swirl chamber separator or cyclone separator 50 . Such a cyclone separator is described for example in U.S. Pat. Nos. 6,860,915 and 5,239,972, herein incorporated by reference. An outlet 50 b of the swirl chamber is in fluid communication with in inlet 60 a of an impactor or impact separator 60 . such an impact separator is described for example in U.S. Pat. No. 7,258,111; 7,238,216 and 5,024,203. An outlet 60 b of the impactor 60 is in fluid communication with a pressure regulator 70 . The pressure regulator maintains a desired gas pressure within the impact separator and swirl chamber separator by varying the gas flow restriction through the regulator. [0026] Oil that is separated from the gas in the swirl chamber 50 drains through an oil outlet 50 c at a bottom of the swirl chamber 50 . Oil that is separated from the gas in the impactor 60 drains through an oil outlet 60 c at a bottom of the impactor 60 . The outlets 50 c, 60 c can be small drain orifices. The combined oil from the outlets 50 c, 60 c is collected in a conduit or conduits 80 and returned to the crankcase 22 . [0027] The compressor 26 sucks blow-by gases from the crankcase 22 and compresses the blow-by gases to a pre-selected pressure, which may be below 50 PSIG. The blow-by gases are delivered into the swirl chamber 50 and then into the impactor 60 at elevated pressure. Each of the swirl chamber 50 and then into the impactor 60 separate some oil from the oil entrained blow-by gases. The pressure regulator 70 can be set to a desired working pressure to maintain elevated pressures within the components 50 , 60 and allow cleaned gas to pass into a discharge conduit 90 that can either be directed to atmosphere or can be redirected to the engine intake manifold for a normally aspirated engine or to the turbocharger compressor for a turbocharged engine. Alternately, with a sufficient arrangement of valves, the discharge conduit could be directed into the exhaust system. [0028] Pressure pulses from the compressor, in the form of a piston pump compressor, aid in the separation of oil and gas from the blow-by gases, because of the instantaneous high velocity of blow-by gases that enter the impactor. [0029] According to one embodiment of the invention, the size of the compressor should be large enough to outpace the amount of blow-by gases that are drawn into the compressor, which may be as high as 700 CFH (ft 3 /hour). If the compressor is of the piston type with one-way valve or valves, the piston should be orientated in a manner where the outlet valve is at the lowest point, below the piston so that any condensed oil can drain through the drain orifice and back into the engine to prevent oil from pooling and overwhelming the system when it leaves the compressor. [0030] The swirl chamber 50 and impactor 60 typically have no moving components and the swirl chamber 50 and impactor 60 can be cast as part of a common or unitary housing. [0031] Additionally, impactors of current design typically require high gas velocity to function. Therefore, small orifices are typically required but are restrictive such as to require a significant pressure drop. However, according to the disclosed embodiment, the compressor elevates the pressure of the blow-by gases to push the air through smaller orifices at higher velocity, i.e., more pressure drop is available. Furthermore, the high velocity of the cleaned blow-by gases from the impactor may reduce condensation and possible ice buildup in the discharge conduit 90 . [0032] A screen (not shown) can be used at each of the oil outlets 50 c, 60 c to protect the outlets from clogging with debris. The oil drain diameters for the outlets 50 c, 60 c can be sized in a manner that allows the system 10 to keep up with the amount of oil that is being separated from gas but not allow excessive loss of pressure by venting gas. During high engine speed and low power operation, the outlets 50 c, 60 c will normally be clear of oil and gas pressure may vent through the outlets 50 c, 60 c to the crankcase, which will then vent back to the compressor. This is not detrimental to the system 10 or to engine operation during these engine operating conditions. [0033] A bypass conduit 110 can be provided to direct gas from the low pressure output of the regulator 70 at the discharge conduit 90 to a low pressure compressor intake at the conduit 28 . When engine speed is high and the load is low, the compressor will be oversized for the amount of blow-by gas generated, which would result in formation of a vacuum within the engine. To avoid this condition, the bypass conduit 110 can be used to re-circulate cleaned blow-by gas from the discharge conduit 90 back into the compressor 26 where it is re-introduced to the separators 50 , 60 , re-cleaned and proper crankcase pressure can be maintained. [0034] If under unusual circumstances blow-by volume from the engine exceeds compressor capacity, the excess blow-by gas will bypass the compressor through the bypass conduit 110 and discharge through the discharge conduit 90 . [0035] Parts List [0036] 10 engine breather system [0037] 20 engine [0038] 22 crankcase [0039] 23 upper engine internal volume [0040] 24 valve cover [0041] 26 pump or compressor [0042] 28 conduit [0043] 50 swirl chamber or cyclone separator [0044] 50 a swirl chamber gas inlet [0045] 50 b swirl chamber gas outlet [0046] 50 c swirl chamber oil outlet [0047] 60 impact separator or impactor [0048] 60 a impactor gas inlet [0049] 60 b impactor gas outlet [0050] 60 c impactor oil outlet [0051] 70 pressure regulator [0052] 80 conduits [0053] 90 discharge conduit [0054] 110 bypass conduit [0055] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.

A breather system for a crankcase of an internal combustion engine includes a gas compressor configured to elevate the pressure of crankcase blow-by gas. At least one gas-oil separator receives gas with entrained oil from the compressor, separates oil from the gas and discharges cleaned gas. The oil is re-circulated back to the crankcase. The cleaned gas is either discharged through the engine exhaust system or re-circulated back into the engine combustion air intake. A bypass conduit allows cleaned gas to be re-circulated from the gas-oil separator outlet to the compressor inlet to balance the blow-by production with the capacity of the compressor.

RELATED APPLICATION This case is a division of U.S. application Ser. No. 965,540, filed Dec. 1, 1978 now U.S. Pat. No. 4,223,430. BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a resilient seat for a butterfly valve, and more particularly to an improved method of manufacturing a resilient valve seat assembly having a flexible ring therein. Typical resilient seats for butterfly valves are made of molded elastomeric material such as rubber. It has recently been found that an improved resilient seat is an annular seat of elastomeric material having a flexible circular band embedded therein. Such a seat assembly is disclosed in our co-pending Canadian application Ser. No. 276,542 filed Apr. 20, 1977. As described in this application, the resilient seat assembly is mounted in the body of a butterfly valve, and a circular disc is mounted within the seat assembly to seal the valve when the disc is closed. Initially the resilient seat assembly was made by commencing with a continuous circular band or ring of flexible steel which had two holes diametrically opposed for a shaft to support the circular disc. Separate strips of material were added as stiffeners around the two holes to strengthen the band at these two areas. This construction required at least three separate pieces to be joined by welding or riveting in a somewhat complex jig. Furthermore, when the circular band is assembled it has to be supported at the centre of a mold whilst the resilient material was inserted into the mold and allowed to harden to form the seat assembly. Supporting the band in the mold presents a number of problems, in one case the band shifted in the mold resulting in the seat assembly having the band eccentrically located and this affected the sealing of the disc on the seat. In another case, the resilient material was omitted from the outside surface of the band thus allowing the outside surface to be held in the mold during the forming step. However, it has been found that unless the band is completely embedded in the resilient material, separation occurs between the band and the material. Other methods using a mold with many parts is partially successful but the complexities of the mold and the time to assemble it cause expensive and time-consuming production. It is, therefore, one purpose of the present invention to provide a simpler and less costly method of constructing a butterfly valve seat assembly. It is a further purpose of the present invention to provide an improved method of constructing a seat assembly with a flexible band properly embedded in resilient material. It is another purpose of the present invention to provide an improved valve seat assembly. In accordance with the present invention there is provided a method for making a seat assembly for a butterfly valve which comprises supporting a flexible, circular band in a fixed spatial position, positioning a mold about, but spaced from, the band while the band is supported, and molding an annular seat member from resilient material while the mold is positioned about the band to substantially embed the band within the seat member. Furthermore, in a preferred embodiment the present invention provides the circular band being formed by overlapping the ends of two part circular, flexible band segments to form a circular band and joining the ends together. The present invention is further directed toward a seat assembly for a butterfly valve comprising an annular, resilient seat member and a circular, flexible band embedded with the annular seat member. The circular band comprises two, part circular segments the ends of which are overlapped and joined together. The invention will now be described in detail having reference to the accompanying drawings in which, BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross sectional side view of a butterfly valve having a seat assembly according to one embodiment of the present invention. FIG. 2 is a cross sectional plan view taken at line 2--2 of FIG. 1. FIG. 3 is a partial cross sectional side view through a portion of the stem and disc of the valve shown in FIG. 1 positioned between two flanges. FIG. 4 is a perspective view of the flexible band which is embedded in the seat assembly. FIG. 5 is a plan view showing how the band is supported in a fixed spatial position. FIG. 6 is a cross sectional view showing the mold positioned about the supported band. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the wafer type butterfly valve has a rigid annular body 10 as seen in FIGS. 1 and 2. The annular body has two internal ribs 11 as seen in FIG. 2. It will be apparent to those skilled in the art, that these two ribs 11 could be solid. These ribs 11 extend around the internal circumference of the body 10 and provide an annular space 12 between them. Opposing external parallel end surfaces 13 of the annular body 10 are adapted for clamping by opposing flanges 14 as shown in FIG. 3. A seat assembly 15 of generally annular shape is located within the annular body 10. The seat assembly has two external flanges 16, one at each side extending beyond the diameter of the seat assembly 15. The flanges 16 are gripped between the outside surface of the internal ribs 11 of the annular body 10 and the opposing mounting flanges 14 and leave a space 17 between the ends of the internal ribs 11 to allow some movement of the seat assembly 15 within the annular body 10. A circular closure disc 18 is mounted within the seat assembly 15. The disc 18 is fixed to a shaft or stem 19 after mounting within the annular body 10. The stem 19 passes diametrically through the disc 18. One end of the stem 19 passes through the seat assembly 15 and is mounted in a socket 20 in the annular body 10. The other end of the stem 19 passes through the seat assembly 15 and a bore 21 in the annular body 10, and projects upwards connecting at the end to a handle 22. Rotation of the stem 19 by the handle 22 rotates disc 18 to open or close the valve. When the valve is closed, the outer edge 23 of disc 18 seats tightly on the inner cylindrical surface 25 of the seat assembly 15. The seat assembly 15 comprises a flexible, circular band 26 embedded within annular resilient seat material. The flexible, circular band 26 preferably in accordance with the present invention, comprises two partly circular segments 27 and 28 as shown in FIG. 4. Each of the two segments 27 and 28 extends over an angle of about 250°. Edges 29 and 30 of the segments 27 and 28 respectively, are cut on the diagonal to distribute stress more gradually instead of providing a sudden change in section at the point of overlap. The end portions of segment 27 overlap the end portions of segment 28 and are joined together by suitable means such as by spotwelds 31. A pair of diametrically opposed holes 32 are provided in band 25 in the overlapped areas "A" of the band. As may be seen in FIG. 1, the stem 19 passes through these holes which are somewhat larger in size than the stem. The annular seat assembly 15 has an outer cylindrical surface 33 concentric with the inner cylindrical surface 25 and side surfaces 34 extending from the inner cylindrical surface 25 and side surfaces 34 extending from the inner cylindrical surface 25 along the outside of the external flanges 16. A section through the seat assembly 15 defines a U-shaped channel. Each side surface 33 of the seat assembly 15 can also have a pair of raised, circular ridges 35 for sealing the valve between the mounting flanges 14. The annular seat assembly 15 also has a pair of diametrically opposed cylindrical holes 36 aligned with the holes 32 on the embedded band 26. The holes 36 are approximately the same size as the stem 19 which passes snugly therethrough. Circular ribs 37 can be provided on the inside surface of the holes 36 to seat against stem 19. It will be noted that the inside edges of the holes 32 in the band 26 are covered with a thin layer of the resilient material of the seat assembly 15. The flexible circular band 26 is made of material which can deform under uneven stresses but return to its original shape when the stresses are released. A suitable material would be steel particularly stainless steel. The material from which the seat material is formed is preferably rubber, or another suitable thermoplastic material. The band 26 is preferably provided with means by which it can be supported during manufacture of the seat assembly. These support means can comprise notches 38 in one edge 39 of the band as shown in FIG. 4. Preferably four notches 38 are provided, two in each segment 27, 28. The diagonally opposite notches in the segment are preferably diametrically opposed. The notches 38 receive finger-like ring locating support members 40 which support the circular band 26 in a fixed, spatial position during manufacture of the seat assembly as shown in FIGS. 5 and 6. A first pair of support members 40 and a second pair of support members 40 are mounted for reciprocal movement toward and away from each other. Each pair of support members 40 can be mounted on a common support 42 which is moved by hydraulic means 43 or other suitable moving means. Each support member 40 has an arcuate leading edge 45 with the same curvature as the band 26. The support member 40 is stepped down adjacent the leading edge 45 providing a shoulder 46 having the same curvature as the leading edge. The stepped surface 47, between shoulder 46 and leading edge 45 supports the band 26 as will be described. A mold 50 as shown in FIGS. 6 is provided for molding the seat assembly 15. The mold 50 includes a two part inner mold 51, 52 and a two part outer mold 53, 54. The outer molds 53, 54 are semi-circular in shape and move together to define the surfaces of the circular in shape and move together to define the surfaces of the circular U-shaped cross section of the annular seat assembly 15. The outer molds 53, 54 have notches 55 through which the support members 40 pass. Suitable means (not shown) move the molds 53, 54 together. The inner mold parts 51, 52 define the outer surfaces 34 of the external flanges 16 and the cylindrical inner surface 25 of the seat assembly 15. Suitable means (not shown) are provided for moving the inner mold parts 51, 52 together, and against outer mold parts 53, 54 to define a cavity defining the shape of annular seat assembly 15. To manufacture the seat assembly 15 the band 26 is first supported by finger-like support members 40. The opposed support members 40 are moved toward each other with the leading edge 45 of the members 40 passing into the notches 38 in band 26 and with the curved shoulder 46 on each member 40 moving against the curved outer surface of the band 26. The members 40 grip and hold the band 26 horizontally in a fixed spatial position. The outer molds 53, 54 are then moved together, surrounding the held band 26 but spaced slightly therefrom. The noches 55 in the molds 53, 54 receive the members 40 as the molds 53, 54 are moved together. Now the inner molds 51, 52 are moved together and abut the outer molds defining an annular cavity surrounding but spaced from band 26. The band 26 is centrally located within the cavity and firmly gripped by members 40. Resilient molding material is then introduced into the cavity through one or more inlets (not shown) in the mold by suitable injections means (not shown). The resilient molding material flows about the band 26 embedding it to form the resilient annular seat assembly 15. The mold sections 51, 52, 53, 54 are then withdrawn as are the members 40 leaving a completed seat assembly 15. The seat assembly 15 can be manufactured in the above manner using any form of flexible band 26. It is preferred, however, to use the novel two-part band described.

A method of making an improved seat assembly for a butterfly valve. The seat assembly comprises a flexible, circular metal band embedded in a resilient material to form an annular seat assembly. The assembly is made by supporting the band in a fixed spatial position on movable finger members, positioning a mold about, but spaced from, the band, and molding the annular seat assembly in the mold to embed the band. The invention is also directed toward an improved seat assembly. In a preferred embodiment the circular band is made of two curved sections overlapping at the two joints and having diametrically opposite holes in the two overlapping areas.

FIELD OF THE INVENTION The present invention relates to retractable blade knives. In particular, the retractable blade knife of the present invention relates to a knife providing a blade that is protected within a handle when the blade is not in use, and where the handle is orthogonal to the blade. The invention also provides a new cutting edge for knives that presents a series of cutting segments that are at angles with respect to adjacent cutting segments, where the angles vary over a range of values within a series of cutting segments on a blade. BACKGROUND OF THE INVENTION Knives with mechanisms for protecting the knife blade when not in use are known. Some of these knives are of a folding variety, with a blade that pivots from an open position to a folded position where the blade is protected within an opening in the knife handle. Another variety of protecting mechanism allows for retraction of the knife blade. In this variety the knife blade can be moved from an open position which has the blade extended from the knife handle, to a closed position which has the blade disposed within an opening within the knife handle, and where the movement of the knife is substantially linear. An example of the first variety of knife is the common folding pocketknife. An example of the second variety is the common utility knife. These knives have limitations in their use however, because they are basically gripped in the same manner. There remains a need in the art for a convenient, retractable knife that is comfortable to hold and use, and yet is suitable for cutting uses such as those for which utility knives are used. Knives are known that have blades which are substantially in line with the knife handle. Although these knives are suited to some cutting tasks, other cutting tasks are accomplished more readily with knives having blades at an angle to the knife handle. A need exists in the art for a knife that can be held in positions other than with the knife blade extending from the axis defined by a clenched fist. For cutting a sheet material such as linoleum for example, it is common to use a knife having its blade at an angle other than zero degrees to its handle. This angle allows the knife blade to be pulled through linoleum while clearance for the user's knuckles above the surface of the floor is provided. Thus, some cutting tasks are better suited to a knife with a blade in a different orientation than that found in common knives. That is, some cutting tasks would be more easily accomplished with a knife whose cutting edge would be presented in a particular orientation with respect to the hand holding the knife. Fatigue to the hand being used to hold the knife can be avoided, and safety of use can result from such a change in orientation of the blade. In particular a need exists in the art for a knife that has a blade orthogonal to the knife handle. A need also exists in the art for a knife having a blade orthogonal to its handle, and whose knife blade is also retractable. The retractable blade knife of the present invention as described herein meets these needs. As disclosed in U.S. Pat. No. 2,359,098 to Engle, a knife is known that has a blade that is orthogonal to its handle. The blade arrangement taught in this patent does not provide for retraction of the blade, although it does provide a mechanism for adjustment to the size of a user's hand. The blade of the knife taught in this patent is always exposed, there being no retraction mechanism. The use of a knife as taught in this patent has a potential safety problem for a careless user. The knife as taught by the present invention addresses this problem by providing for retraction of its blade. U.S. Pat. No. 1,322,775 to Fallon discloses a bladed military weapon whose blade is held in line with a user's forearm, and orthogonal to the axis of the user's clenched fist. This weapon is taught as having an extension that grips the forearm of the user. This weapon is taught as having a pivoting mechanism for the blade that allows the blade to be pivoted from a service position to a folded position above the forearm. The arrangement taught by Fallon does not provide any structure that receives a blade to protect a user against accidental cuts. Also, the weapon as taught by Fallon does not provide any means for retracting the blade of the weapon. U.S. Pat. No. 5,025,560 to Townsend discloses an ergonomic knife that has a blade that is held orthogonal to a clenched fist of a user when in use for cutting. This knife also has a mechanism for pivoting the blade into a range of cutting positions relative to an extended support member that reaches part way up the forearm and is attached to the forearm of a user. For use, the knife disclosed requires attachment to the forearm, which can be an inconvenience and shortcoming in use. Another shortcoming is that the knife as taught by Townsend has no mechanism for retraction of its blade to a protecting position that would protect a user from accidental cuts. Another knife having a blade orthogonal to its handle as used was disclosed in United States Design Patent D301,048 to Hollinshead. This particular knife design teaches a knife whose blade is not retractable. The blade of this knife does not extend directly to the handle, but is attached to the knife handle with two blade extension members whose attachment point to the handle are spaced apart by at least two finger widths. This knife also lacks a mechanism for retraction of its blade. U.S. Pat. No. 4,096,629 to Levine discloses a claw weapon that has multiple retractable blades. This claw weapon has blades that while in use, project outwardly between adjoining fingers of a user's hand. The claw weapon comprises a tubular grip member that contains the blades when the blades are in a retracted position. As taught in the Levine patent, the fingers of a user are in very close proximity to the cutting edges of the multiple blades. An inadvertent shifting of the fingers of a user could expose the fingers to cuts from the blades as such a weapon is being used. This is a serious shortcoming with a weapon according to this teaching. The weapon taught by this patent also lacks a locking mechanism for retaining its blades in an extended position. U.S. Pat. No. 2,741,025 to Stewart discloses a weapon having a pointed dagger element fixed orthogonal to a gripping member; and also having a tubular sheath of soft elastic material disposed around the dagger element, for protecting a user from the pointed dagger element in storage and for slidably exposing the dagger element in use as a weapon. This weapon does not have a blade. The use of a soft elastic sheath as taught by Stewart would be impractical with a knife blade having edges along the blade's length, because the sheath would be expected to be cut by the knife edges during handling and damaged, if pressure were brought to bear on the sides of the soft elastic sheath. Moreover, the use of a soft elastic material for a sheath around a knife blade would expose the fingers of a user to cuts if the fingers should push against the soft material. These are shortcomings for the weapon as taught by Stewart. A need exists therefore for a knife with a blade that is orthogonal to its handle, and where the blade is also retractable. A need also exists for this blade to be easily retractable without binding of the retraction mechanism. A further need exists for a knife with such an orthogonal, retractable blade where the blade can be locked in an extended position. Still another need exists for a retractable blade knife where the blade will be enclosed while retracted to protect the user, and where the blade while extended will avoid having a cutting edge in close enough proximity to the fingers of a user to endanger the fingers. As shown in A. G. Russell Catalog of Knives Spring 1999, p. 51, April, 1999, knives with blades having an irregular edge are known. Such blades appear to be made of materials that are easily fractured and flaked, such as flint or obsidian. These knives with an irregular edge have been used for many years and have been found particularly useful for cutting some materials. These knives have blades that lack certain strengths such as the ability to bend and cut without breaking across the width of the blade however. This lack of certain strengths is a serious shortcoming for the knives with flint or obsidian blades. A need therefore exists for a blade with an edge that is similar to an irregular edge, but that is made of a metal and that can be reproducibly manufactured. To overcome such shortcomings, a blade edge is disclosed here that provides a cutting edge somewhat similar in appearance to the irregular edge used on flint or obsidian blades, but that is also suited for use with a metal knife blade. To overcome the shortcomings of known knives above, and to satisfy the outstanding needs outlined above I have now discovered a new retractable knife. I have also discovered a new knife edge that can be used with the new retractable knife, or with other knives or other cutting implements. SUMMARY OF THE INVENTION Briefly, the invention is a knife with a retractable blade where the blade is orthogonal to the knife handle. The new knife comprises a handle with two handle elements. One element is a palm gripping member. The other element is a finger gripping member that has a slot extending through it, and that is parallel to the palm gripping member. An elongated blade is fixed at one of its ends to the palm gripping member and the blade extends through the slot, the slot being sized to accommodate passage of the blade. A biasing, member having two ends is fixed at its first end to the palm gripping member, and is fixed at its second end to the finger gripping member. The biasing member is substantially orthogonal to both of the gripping members. The biasing member is also sized and shaped to receive the blade within the biasing member. That is, the biasing member surrounds the blade, or can hold the blade within itself. The blade is retractable from a first extended position to a second retracted position in response to biasing extension of the biasing member. A stabilizer bar, depending from the finger gripping member, slides in a longitudinal slot in the blade. The finger gripping member has at least two openings through it, the openings sized and shaped to receive fingers of a user. The finger openings are preferably spaced apart sufficiently to permit the blade passing slot and the blade to be disposed between the finger openings. This arrangement then ensures that the fingers of a user are separated from the blade by portions of the finger gripping, member. Preferably, the biasing member comprises either one or two coiled springs. It is preferred that the biasing member have an oval transverse section for more readily accommodating the blade. The biasing member surrounds the blade in a retracted position, thereby protecting the user from accidental cuts. A new cutting edge for use on knife blades is also disclosed here. By edge here is meant the region of a blade that is adapted for use as the cutting side of a blade. The new edge comprises a series of cutting segments along a blade. The cutting segments are each substantially linear, and are in end to end relationship for forming the edge. Each of the cutting segments is disposed at a selected angle of up to about 25 degrees from the line of a contiguous cutting segment. That is, when any pair of contiguous cutting segments is considered, one of the pair forms an angle of up to about 25 degrees with respect to the other of the pair. A cutting segment deviates from the line of a contiguous cutting segment up to about 25 degrees however with the proviso that the overall width of the blade edge so formed is no more than about 3 mm (millimeters). In effect then, the cutting edge of the invention is made up of a series of very small edge portions, the cutting segments. The visual effect of this arrangement when viewed from the plane of the blade is that of a meandering edge, having the general appearance of a flint knife's edge. The visual effect when viewed from the side of the blade is also that of a meandering edge with this same general appearance. The new knife edge can have these cutting segments each sharpened to present a bevel such as is commonly found on the blades of ordinary knives. Preferably, the edge comprises cutting segments with two substantially parallel opposed sides and a face distal from the blade body that supports the cutting edges. The preferred length of the cutting segments is from about 0.2 mm to about 1 cm (centimeter), and the preferred thickness between the opposed sides is from about 0.5 mm to about 1.5 mm and is most preferred to be about 1 mm. The form of the new knife edge can be used on a particular knife blade by itself or in combination with a conventional edge such as a bevel. That is, an edge of a particular knife may be divided into regions, one region of which has a conventional bevel, and the other region of which is composed of the end to end cutting segments as disclosed herein. A particular knife may also have an edge that is divided into two regions where one region has a conventional serrated edge profile, and the other region is composed of the end to end cutting segments disclosed herein. The new knife edge can also have cutting nodules distributed along the cutting segments, where the cutting nodules are pieces of a material that is sufficiently hard to resist being readily worn down during use of the knife edge, and where the cutting nodules project from the cutting segments. Preferably, the nodules are substantially hemispherical in overall shape and have a sharp, jagged, irregular surface texture for providing a component of abrasion to the cutting effect of the edge. The nodules may be made of a metal or a ceramic material. If made of a metal, the metal may be the same as that used for the rest of the blade or a different metal may be used. A knife according to the present invention can have one blade edge that was ground to present a conventional bevel, and can have a second blade edge with the latter being the inventive knife edge comprised of the cutting segments in end to end relationship at varying angles to one another. An advantage to having both the inventive knife edge and a conventional bevel edge in a single knife blade is that a user can select whichever cutting edge is best suited to a given cutting task at hand. The knife according to the present invention can be rotated in the user's hand to allow the selection of the better of two cutting edges for the given task. It is accordingly an aspect of the invention to provide a retractable blade knife where the blade is orthogonal to the handle. It is another aspect of the invention to provide a retractable blade knife having a biasing member that biases the blade to a retracted position. It is another aspect of the invention to provide a retractable blade knife with a locking mechanism that allows the blade to be locked in an extended position. It is yet another aspect of the invention to provide a new cutting edge for use on knives and other cutting tools, where the new cutting edge has characteristics of a meandering edge for aggressively cutting difficult materials. It is yet another aspect of the invention to provide a new manmade cutting edge for use on knives and other cutting tools, where the new cutting edge roughly imitates the overall appearance of a flaked stone knife, but which is distinguished by having distinct and well defined dimensional constraints for a series of cutting segments. It is still another aspect of the invention to provide a retractable blade knife that comprises the new cutting edge. These aspects, and others set forth more fully below are achieved by the present invention. In particular, a new knife is disclosed that reduces fatigue for the user, has a retractable blade, can provide an optional locking mechanism for the blade, and that preferably has an inventive blade for providing aggressive cutting action. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustration of a front elevation view of a first embodiment of a knife according to the invention, with the blade in an extended position. FIG. 2 is an illustration of a front elevation view of the first embodiment, with the blade in a retracted position. FIG. 3 is an illustration of a front elevation view of a finger gripping member of the first embodiment. FIG. 4 is an illustration of a front elevation view of a palm gripping member of the first embodiment. FIG. 5 is an illustration of a front elevation view of a second embodiment of a knife according to the invention, this embodiment having a locking mechanism. FIG. 6 is an illustration of an edge elevation view of the second embodiment. FIG. 7 is an illustration of a top view of the extension member of the first embodiment. FIG. 8 is an illustration of a pair of coil springs from the extension member of FIG. 7. FIG. 9 is an illustration of an edge elevation view of a blade according to the invention. FIG. 10 is an illustration of an enlargement of a section of FIG. 9, showing details of the blade edge according to the teaching of the invention. FIG. 11 is an illustration of a set of possible edge profiles for cutting segments according to the teaching of the invention. FIG. 12 is an illustration of a set of possible edge profiles according to the teaching of the invention, having cutting nodules disposed along the edge. FIG. 13 is an illustration of the elevation view of a cutting nodule according to the teaching of the invention. DETAILED DESCRIPTION OF THE INVENTION I have developed a new and improved retractable blade knife, well suited for use as a utility knife. I have also developed a new and improved cutting edge for use on knives and other cutting implements. The knife and cutting edge will be understood more clearly by reference to the accompanying drawings. With reference to these drawings, wherein like reference numerals designate similar parts throughout the various views, 12 designates the palm gripping member of the knife embodiment 10 depicted in FIG. 1. The number 14 designates the finger gripping member, and 16 designates the blade. A biasing member 18 connects the palm gripping member 12 and finger gripping member 14. The biasing member 18 is orthogonal to the palm gripping member 12 and fastened to it by a pair of stays 22. The biasing member 18 is orthogonal to the finger gripping member 14 as well, and is fastened to it by a pair of stays 24. The blade 16 has a first end 26 fastened to the palm gripping member 12 at region 28. The second end 32 of the blade 16 extends through a slot 34 through the finger gripping member 14. The finger gripping member 14 for the embodiment shown has four openings 36 for receiving fingers. It is to be understood that the finger openings 36 could be merged into three or into only two finger openings of appropriate dimensions without losing their function as gripping points for fingers of a user. It is also to be understood that the finger openings 36 could be arranged at various angles to make a particular user's grip more comfortable without deviating from the teachings of the invention. The finger gripping member 14 comprises a stabilizer bar 38 that depends from a side of the finger gripping member 14 into the slot 34 through the member 14. the blade 16 has a longitudinal slot 42 mortised into it that is dimensioned to receive and slidably engage the stabilizer bar 38 for motion within the slot 42. The biasing member 18 in the embodiment shown comprises a pair of coiled springs, having oval cross sections, the springs being coaxial and intertwined. The biasing member 18 is shown in more detail in an end view, showing a preferred oval shape, in FIG. 7. As shown, the two springs are coils with opposite handedness, one being right handed and one being left handed. In FIG. 8 can be seen an elevation view of the two springs, 52 and 54, that make up the biasing element 18. Other arrangements of springs are also to be recognized as suitable for practicing the invention such as a pair of springs which are coaxial, but of slightly different diameters. This particular alternate arrangement provides a spring that can fit into the cavity of the second spring while the springs still have a common axis. Constant force springs are known in the art and are also to be recognized as capable of use in the inventive knife. It is to be understood that the biasing member 18 can comprise a single coiled spring of appropriate size and shape. It has been found however that two coiled springs as shown in FIG. 1 and FIG. 8 are preferable for the smooth operation of a knife according to the teaching of the invention. The openings 36 through the finger gripping member 14 may be sized, shaped, angled and positioned at various locations in the finger gripping member to allow fingers of various sizes to conveniently grip the new knife. For example, two oval openings (not shown) can be substituted for the four openings shown, each oval opening accommodating fingers. This latter arrangement is to be considered as still within the teaching of the present invention. By having the user's fingers received within the openings of the finger gripping member, protection from the blade edges is afforded to the fingers by the separation of the fingers from the edges. In FIG. 2 may be seen the knife embodiment of FIG. 1, where the knife is in a retracted position. By relaxing the user's grip on the knife, the biasing element 18 is allowed to urge the finger gripping and palm gripping members 14, 12 to become spaced apart. This allows the biasing member 18 to surround the blade 16. The user's hand is thereby protected from the first edge 56 and second edge 58 of the blade. It is preferable that the inventive knife 10 be dimensioned so that when the biasing element 18 is fully extended, the blade 16 will be fully retracted into the biasing element 18 and the second end 32 of the blade 16 will be enclosed within the biasing element 18. The blade 16 has a longitudinal slot 42 mortised into it that receives a stabilizer bar 38 that depends from the finger gripping member 14. The length of the longitudinal slot 42 may be selected to limit the spacing apart of the finger gripping member 14 and palm gripping member 12 that is achieved by the biasing member's extension. FIG. 3 depicts a finger gripping member 14 and shows more clearly the stays 24 that may be used to fix the biasing member 18 to the finger gripping member 14. Also shown is the stabilizer bar 38 that depends from the finger gripping member 14 into the slot 34. In FIG. 4 may be seen a palm gripping member 12 and the stays 22 that are used to fix the biasing member 18 to it. Turning to FIG. 5, an alternate embodiment 20 of the inventive knife may be seen. The construction of this embodiment is similar, but this embodiment further comprises at least one transverse slot 46 in the blade, and a locking member 44 that is disposed along the finger gripping member 14 and that is adapted for removably engaging with the transverse slot 46. This engagement restricts the sliding motion of the blade 16 through the slot 34, and retains the blade 16 in a selected position. Proper positioning of at least one transverse slot 46 in proximity to the first end 26 of the blade 26 allows the user to lock the blade in the extended position for use in cutting. Positioning of at least one additional transverse slot 46 in proximity to the second end 32 of the blade allows the user to lock the blade 16 in the retracted position. The shape of the locking member 44 is not critical to the operation of the knife 20 as long as it can be removably engaged with the slot 46 by being closely received within the slot 46. FIG. 6 depicts an edge elevation view of the embodiment 20 seen in FIG. 5. The locking member 44 may be seen more clearly there. The knife of the present invention can be made with conventional bevel edges on the blade. A conventional serrated edge or a conventional saw tooth edge can also be used on the blade. It is preferred that the inventive knife have at least one edge of a type that is disclosed herebelow. The embodiments shown in FIG. 2 and FIG. 5 are depicted with their blades having a first edge 56 with a conventional bevel, and having a second edge 58 with an edge of the type disclosed here. A new edge design has been discovered that is superior to those hitherto known for cutting certain kinds of materials. An edge elevation view of the blade 16 is illustrated in FIG. 9. The inventive edge 58 consists of a series of nearly random, substantially linear cutting segments, segments 62 and 64 being examples of such segments. These segments may vary in length and form the blade edge 58 by the segments being oriented in end to end relationship, where the angle a first segment deviates from the line of a second segment can vary substantially at random up by to about 25 degrees. That is, a pair of contiguous segments forms an angle that can be as large as about 25 degrees. The length of the cutting segments can vary substantially at random from about 0.2 mm to about 1 cm. The cutting segments then meander from the plane of the blade and within the plane of the blade. The edge formed from such a series of cutting segments can have each cutting segment formed into a bevel edge. An edge embodiment as so described will effectively be composed of a series of very small "bladelets" which can be viewed as forming a meandering path down the blade as a whole. In FIG. 10 may be seen an example of such an edge. The cutting edge is seen as twisting from side to side along the blade, but the inventive edge is formed with the proviso that the maximum width of the edge is up to about 3 mm. In a preferred embodiment, the inventive edge comprises cutting segments where each cutting segment is also of 0.2 mm to 1.0 cm in length, and where the angle each cutting segment deviates from the line of a contiguous cutting segment varies substantially at random to about 25 degrees. And, in addition, the cutting segments have two substantially parallel opposed sides 66 and a face 68 distal the supporting blade, provided that the thickness of each of the cutting segments is about 1 mm. The distal face may have a jagged, irregular profile. In FIG. 11 are illustrated examples of the possible jagged, irregular profiles that can be encompassed by the design of the inventive blade. The parallel opposed sides 66 are referenced for one of the examples shown, and the distal face 68 is referenced for another example. By "jagged, irregular" is meant that the profile of each cutting segment varies substantially randomly in height and shape over the face of the profile, in a direction normal to the distal face. The cutting segments may form a regular repeating pattern to make up a cutting edge, however it is preferred that the cutting segments not form a regular repeating pattern in forming a cutting edge. That is, the set of cutting segments used for a given knife edge should present to the eye of a user an irregular pattern. If a regular repeating pattern of cutting segments is present, the pattern should repeat over a distance sufficiently long to not have the repetition readily apparent to a viewer without close inspection. In this latter case, the appearance of irregularity will be present. The inventive cutting edge is not completely irregular however, but is distinctly described by the limitations disclosed here. A more highly preferred embodiment of the inventive edge for cutting is similar to the one just disclosed above, but farther comprising cutting nodules disposed along the edge. It is preferred that these cutting nodules be substantially hemispherical in shape and from about 0.05 mm to about 0.4 mm in diameter. The cutting nodules should have a sharp, jagged, irregular surface. The cutting nodules may be made of the same material as the bulk of the blade, such as a steel, titanium, tungsten carbide, or a metal alloy containing either iron, titanium or tungsten. Alternatively, the cutting nodules may be made of a ceramic material. FIG. 12 illustrates examples of profiles for cutting segments which are encompassed by the invention, where the cutting segments have disposed along them cutting nodules 72. FIG. 13 illustrates the type of cutting nodule 72 suited for use with the present invention, having a sharp, jagged, irregular surface. The nodules selected for use in practicing the invention should have sharp surfaces, suitable for use as an abrasive. The quantity of nodules that should be used on a given blade edge may be selected by a manufacturer according to the type of material to be cut and the cost associated with the addition of nodules to the blade. A knife edge with the structure disclosed here will be useful for aggressive cutting of a variety of materials usually found difficult to cut with conventional knife edges, and will have the advantage of a pleasing appearance that suggests irregularity to a viewer of the knife edge while not being completely irregular. The palm gripping member, finger gripping member, and spring stays of the device are preferably constructed of plastic, wood, or metal. The blade can be made of a steel, but is preferably constructed of a metal such as tungsten carbide. The spring is preferably constructed of steel. A blade according to the teaching of the invention is preferably made by a casting process, as would be known to one skilled in the art of metal casting. The edges of the blade can also be ground using a conventional knife sharpening method to provide a conventional cutting edge. Conventional knives use blades with an edge that is usually sharpened to present a thin bevel section for cutting, uniform along the length of the blade. Some blades have been used that have a serrated edge, where the edge has been ground in a regular series of scallops. A blade with such serrations or scallops can be more aggressive for cutting than a straight edge. This increased aggression presumably occurs because the edge is effectively made up of a linear array of very small blades, and using such a blade subjects the workpiece to be cut with many small blades that attack the workpiece at different angles. Irrespective of any theory of cutting, knives with a serrated edge are frequently viewed as more efficient cutting tools than knives with a straight edge. In the present invention, a blade is disclosed that has advantages over a blade with a conventional serrated edge, or a conventional saw tooth edge. In particular, it has now been discovered that by having a blade edge composed of an array of cutting segments that twist and turn at varying angles as viewed down the edge of the blade, a knife is provided with an edge that can cut more efficiently through some materials than can conventional serrated edges. It has also been discovered that the inventive cutting edge is improved substantially for use in cutting certain materials by having sharp, jagged, irregular distal surfaces and by having the cutting nodules described here distributed along the cutting edge. It is to be understood that the blade used in the knife of the present invention may be permanently fixed to the palm gripping member, or may be removably fixed. In the latter case, the knife may be adapted to utilize user replaceable blades. The present invention is not to be limited in scope by the embodiments disclosed herein, which are intended as single illustrations of one aspect of the invention, and any which are functionally equivalent are within the scope of the invention. Indeed, various modifications of the invention, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims. All patents and any publications mentioned herein are hereby incorporated by reference.

A retractable blade knife is described, which has a handle composed of two parallel members connected by biasing spring assemblies and a blade orthogonal to the handle members. A cutting edge comprising cutting segments connected at varying angles to one another is disclosed, the cutting edge providing a visual effect similar to a flaked cutting edge.

BACKGROUND OF THE INVENTION This invention is related to an apparatus and method for controlling the direction of a vehicle travelling through a fluid medium. More particularly this invention constitutes a unique method and apparatus for actuating the aft control surfaces of a submarine with X-shaped empennage. Most modern military submarines have a hull form that at least approximates an axisymmetric body of revolution. Most of these have four control surfaces at the stern for steering the vessel, that is, for making it turn left or right—the rudder—or rise or dive—diving plane—or a combination of both. In turn, in most modern submarines these control surfaces are in cruciform. That is, the rise-dive surfaces are generally in the same plane as the horizontal plane through the centerline of the vessel, and the turning surfaces are in the same plane as the vertical plane through the centerline. Thus, the control surfaces are generally in the form of a Greek cross. In most cases the two rudder planes are yoked together, and the two diving planes are yoked together. Because of this yoking, each pair of control surfaces is operated by a single actuating rod. Thus, one rod turns the ship, and the other rod causes the ship to rise or dive. It is known that arranging the control surfaces or planes of a submarine in an X configuration has certain advantages. In this form, the control surfaces are in the form of an X. Unlike cruciform designs, X-stern designs utilize all four planes as part of any maneuver. Therefore, an X-stern design enjoys more maneuvering force per unit of control surface area than cruciform designs. X-stern ships can be designed with smaller control surfaces while maintaining maneuvering envelopes comparable to cruciform ships with larger control surfaces. Smaller control surfaces obviously have less drag, but may also be quieter—a very important factor today for a submarine. The submarine USS ALBACORE had an X-stern configuration where the opposite control surfaces were yoked together. Australian submarines of the recent COLLINS class have X-stern configurations, but the control surfaces are not yoked together and each of the four surfaces has its own actuator. These are two examples of the current known methods of actuating X-sterns. In both cases, the control system for the operating rods is more complicated than that aboard a cruciform ship. In a cruciform ship, if the helmsman wants to turn the ship, the control system commands the rudder operating rod to extend or retract. If a change in depth is required, the control system commands the diving operating rod to extend or retract. In both X-stern designs, the control system commands every operating rod to move in one direction or the other, for any maneuver. Controlling these coordinated operating rod movements is a complex task that can be accomplished with a computer. However, manual coordination of the operating rods, in the event of a computer casualty, is difficult. Usually the turning axes of the control surfaces are perpendicular to the ship's centerline at the stern. In this configuration, yoking of the two planes on opposite sides of the ship is an option. Some X-stern configurations require that the turning axes of the control surfaces be tilted such that they are not perpendicular to the ship's centerline. In this case, the control surfaces cannot be yoked, since no two turning axes are collinear. For these designs, the only current method of actuation is to use four separate operating rods. U.S. Pat. No. 3,757,720 gives some idea of the stern arrangement of a submarine. FIG. 2 of the patent shows the mechanism in the stern necessary to actuate the diving planes, including an additional mechanism to actuate a smaller control surface as part of the main surface. Another mechanism of the same type would be required to do the same for the rudder surfaces. U.S. Pat. No. 2,654,334 shows a torpedo with four control surfaces. However, they are in cruciform and have actuating rods 29 and 32 and a control rod 26 . U.S. Pat. No. 5,186,117 shows an altogether different steering system for a submarine mounted at the bow; this patent is assigned to the assignee of the present invention. An X-stern control surface actuation mechanism that requires only two and not four operating rods whether the planes on control surfaces are yoked or not is not known in the prior art but offers the following benefits: a. The space in the stern of most submarines is filled with propulsion shafting and bearings, other equipment and piping, as well as for the control surface actuating mechanisms. Minimizing the number of control rods penetrating this space is highly desirable. b. The operating rods would operate as they would be in a cruciform design. In other words, one rod would cause the ship to turn and the other rod would cause the ship to rise or dive. This would simplify the control system for the operating rods, and make manual operation of the operating rods as simple as it is in a cruciform design. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view partly broken away showing the X-tail configuration of the planes along with the diving operating rod and steering operating rod as well as the inner and outer gimbal rings. FIG. 2 is a perspective view of the X-tail configuration taken aft and looking forward and showing the aft side of the inner and outer rings and the position of the planes in an X-tail configuration. FIG. 3 is a perspective view very similar to that of FIG. 2 but on a larger scale showing in greater detail the spherical connections of the stock connecting rods and the diving and steering operating rods to the outer gimbal ring and the inner gimbal ring. FIG. 4 is a perspective view showing only one pair of planes and their position during a dive of the vessel and also showing the positioning of the movement control assembly formed by the inner and outer gimbal rings. FIG. 5 is a perspective view of all four planes positioned for a turn of the vessel and illustrating particularly the movement of the inner ring relative to the outer ring. FIG. 6 is a perspective view showing each of the four planes in a position for the vessel to take a diving turn and illustrating the position of the outer ring and the inner ring as they have been moved by the diving operating rod and the steering operating rod respectively. FIG. 7 is a schematic view partly broken away illustrating the position of the stock and plane relative to the pedestal and the ship's hull. Also illustrated in phantom lines is an alternate embodiment wherein the stock is angled relative to the main axis of the ship at an angle less than 90 ° but is substantially perpendicular to the contoured surface of the ship. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the essential elements of the invention positioned as they would be in the stern of a vessel such as a submarine, shown at 10 . The parts of the submarine not directly pertinent to an understanding of the invention are omitted. Planes or control surfaces 12 , 14 on the right (starboard) side and 11 , 13 on the left (port) side of the longitudinal centerline of the submarine are located outside the submarine at the stern for contact with the sea. These planes are of conventional shape and design but it is their manipulation and the apparatus for controlling the direction of the submarine that are the novel features of the present invention. The planes 12 , 14 , 11 & 13 move by virtue of the rotation of their solid cylindrical stocks 15 , 19 , 16 , and 18 respectively to which they are secured. The rotation of the stocks and their planes through a limited arc of motion produces turning moments that cause the submarine to move up or down, right or left, or a combination thereof as in rising or diving turns of the submarine. The stocks are rotatably secured at ends 15 a , 19 a , 16 a , and 18 a , respectively to the submarine internal structure by means of suitable bearings and seals, not shown. Also at the locations 15 b , 16 b , 18 b , and 19 b , as shown in FIG. 1, these stocks are rotatably secured at their respective locations through the ship's hull H as shown for one instance at 16 c in FIG. 7 . Similar securings would be accorded stocks 15 , 18 and 19 all using conventional through the hull bearings and seals. Stocks 15 , 19 and 16 , 18 are rotated about their longitudinal axis by the action of stock rods 22 , 26 , 23 and 25 connected at their forward ends to their respective stocks 15 , 19 , 16 and 18 by being pivotally connected to protruding lever arms 20 a , 20 b , 20 c , and 20 d respectively. Each of these lever arms 20 a - 20 d is secured at its inboard ends to its respective stocks and pivotally receive its respective stock rods in a manner such that substantially longitudinal movement of the stock rods produces rotational movements of the individual stocks and therefore the planes 12 , 14 , 11 , and 13 respectively. As best shown in FIGS. 1, 2 , and 3 , these stock rods 22 , 26 , 23 and 25 are connected at their rearward ends to a movement control assembly or gimbal ring assembly shown generally at 30 . The gimbal ring assembly 30 is composed of an outer gimbal ring 34 and inner gimbal ring 38 . The gimbal ring assembly also includes a pair of radially opposed trunnions 34 a and 34 b secured to the outer periphery 34 c of the outer gimbal ring. These trunnions 34 a and 34 b mount the gimbal ring assembly 30 in a pivotal arrangement, not shown, within the interior of the submarine, all in a conventional manner. Pivotally secured to the internal surface 35 of outer gimbal ring is inner gimbal ring 38 . Inner gimbal ring has a cutout center shown at 38 a of FIG. 3 and is also provided with a pair of radially opposed trunnions 38 b and 38 c that are generally positioned along an axis that is transverse to the generally horizontal axis of the trunnions 34 a and 34 b of the outer gimbal ring. It should be understood that, as shown, the gimbal rings are arranged such that the axes of the mounting trunnions 34 a , 34 b , 38 b and 38 c are orthogonally positioned relative to each other, however, there is no reason why other angular arrangements relative to each other or to the longitudinal axis (C/L) of the submarine could not be used to achieve the same or similar purpose or function in the present invention. As shown in FIG. 1 and particularly in FIG. 3, the stock rods 22 , 26 , 23 and 25 are pivotally secured to the inner gimbal ring by spherical rod ending bearings 22 a , 26 a , 23 a and 25 a respectively or by any other conventional arrangement that permits the degree of movement necessary. Accordingly, stock rods 22 , 26 , 23 and 25 are moved substantially longitudinally by the combined or independent movements of outer gimbal ring 34 and inner gimbal ring 38 . Inner gimbal ring 38 pivots about trunnions 38 a and 38 b on an axis that, for example, is essentially vertical, as shown, with respect to the centerline C/L of the submarine. As stated, outer gimbal ring 34 is secured to the submarine structure by means of the trunnions or outer ring bearings 34 a and 34 b but pivots on an axis essentially horizontal with respect to the centerline C/L of the submarine. But, as previously stated, these angular arrangements are not critical and can be changed to achieve the same or similar purpose or function. Diving operating rod 28 and steering operating rod 29 are connected to the gimbal ring assembly 30 to independently or together rotate the respective gimbal rings about their respective axis. As shown, diving operating rod 28 is a cylindrical linear activator and includes connecting rod 28 a that is extensible in any conventional manner from diving operating rod 28 . At the rearward end of the connecting rod 28 a is pivot connector 28 b that pivotally receives elongated diving operating rod extension 28 c for pivotal movement within pivot mount 28 d . The pivotal connection between the diving operating rod extension 28 c and the pivot mount 28 d is conventional allowing the diving operating rod extension 28 c to pivot about axis 28 e. In a similar manner, steering operating rod 29 is shown also to be a cylindrical linear activator and includes connecting rod 29 a , pivot connector 29 b and steering operating rod extension 29 c for connection at the spherical rod end bearing 29 d . The spherical rod end bearing 29 d is similar to the spherical bearing arrangements of 22 a , 23 a , 25 a and 26 a , all of which are secured to the inner gimbal ring 38 . Again, it is to be understood that the functions and the respective connections of the outer and inner gimbal rings 34 and 38 may be reversed from that shown and described without departing from the scope of the present invention. It is also within the purview of the present invention for the gimbal ring 30 to be activated from the rear or the side rather than from a forward position. Also, conventional rotary activators may be substituted for each of the cylindrical linear activator operating rods 28 and 29 . Referring to FIG. 7, there is shown one of the control surfaces or planes 12 that is rotatable by its stock 15 that is shown to be perpendicular to the C/L of the submarine as it passes through the hull H and the pedestal P that protrudes out of the hull H. The pedestal P has a upper surface 40 that is coextensive and substantially congruent with the lower surface 42 of the plane 12 to produce therebetween a gap G. The magnitude of the gap G is important, as well as the alignment of the gap for the performance of the submarine. For instance, it is desirable to have the plane of the gap G substantially parallel to the flow lines of the hull H, generally as shown in FIG. 7 . This minimizes the magnitude of the spacing that forms the gap G, which means lower flow noise and less drag as the submarine traverses the water. If the stock 15 is perpendicular to the main axis or C/L as shown in the position depicted at 15 . 1 in FIG. 7, the gap G must be larger in order to accommodate the transverse movement of the plane 12 as it rotates about an axis that is not perpendicular to the plane of the gap G. It should be apparent that the gap has to be larger if the position of the stock is as shown at 15 . 1 because the movable plane 12 has a finite thickness. As it rotates with respect to the pedestal P, the outer edges of the plane would foul the pedestal if the gap G between the plane 12 and the pedestal P were not large enough. Accordingly, it is preferred that the angle of each of these stocks, such as the example shown in FIG. 7, be lessened with respect to the C/L of the submarine so that the stock is perpendicular to the plane of the gap G, as shown at 44 and therefore at an acute angle with the C/L of the submarine. The magnitude of the acute angle is variable depending upon the magnitude of the gap G and also is variable depending upon the degree of plane rotation. Thus in sum, it may be stated that the stocks of the planes are preferably substantially perpendicular to the flow lines of the hull H at the point that they protrude from the hull H so that they are also substantially parallel to the plane of the gap G to achieve the purpose of the present invention. FIG. 7 along with the foregoing description, illustrate one of the novel benefits of the present invention in that now only two operating rods, rather than the four operating rods of the prior art discussed above, may be utilized to operate the control surfaces or planes having their turning axes tilted from perpendicular to the ship's C/L. For an understanding of the operation of the submarine and the mechanism that controls the movement of the X-tail arrangement, the following description is set forth. FIGS. 1 and 3 depict the positioning of the planes 11 , 12 , 13 , and 14 in a neutral position for straight ahead (cruising) direction of the submarine. In such a position, the gimbal ring assembly 30 and particularly outer gimbal ring 34 and inner ring 38 are in a common plane and that plane is essentially perpendicular to the C/L of the submarine as is apparent in the view from the rear of the submarine. FIG. 3 shows this common plane arrangement of both the outer gimbal ring 34 and the inner gimbal ring 38 . In order to steer the submarine, steering operating rod 29 extends steering connector rod 29 a pivot connector 29 b and steering operating rod extension 29 c rearwardly to the spherical rod end bearing 29 d as it is connected to the inner gimbal 38 . Such extension rotates the inner gimbal ring 38 clockwise about its vertical axis extending through opposed trunnions 38 b and 38 c as shown in FIG. 5 . In this turning maneuver, it should be noted that outer gimbal ring 34 remains stationary and essentially in a vertical plane again as shown in FIG. 5 . The movement of the steering operating rod 29 not only moves the inner gimbal ring 38 but also pushes stock rods 23 and 25 in a forward direction and simultaneously pulls stock rods 22 and 26 in a rearward direction. This movement of the inner gimbal ring 38 and the movement of the stock rods rotates the four stocks 15 , 19 and 16 , 18 through their respective protruding lever arms 20 a through 20 d respectively and ultimately rotates the planes 12 , 14 and 11 , 13 respectively into the position shown clearly in FIG. 5 to produce turning moments on the stern of the submarine. It is obvious, in a reverse manner, to steer the submarine in the opposite direction, steering operating rod 29 is retracted to rotate the inner gimbal ring 38 in a counter clockwise direction about its vertical axis so as to reverse the previously described movement and move the planes 12 , 14 , 11 , and 13 in the opposite direction. When it is desired to dive the submarine, the position of the diving mechanism is illustrated in FIG. 4 . The diving operating rod 28 extends diving connecting rod 28 a rearwardly along with pivot connector 28 b and diving operating rod extension 28 c to achieve the pivotal movement about pivot mount 28 d and therefore rotate outer gimbal ring 34 about its horizontal axis formed by outer ring bearings 34 a and 34 b of which only outer ring bearing 34 a is shown in FIG. 4 . This action and pivotal movement of the outer gimbal ring 34 pulls upper stock rods 22 and 23 rearwardly. In this view from the right side of the submarine, only planes 12 and 14 are illustrated along with their accompanying manipulating elements. Stock rod 22 thus rotates stock 15 through protruding lever arm 20 a and at the same time stock rods 26 and 25 similarly are moved forwardly to rotate their respective planes. For clarity, only plane 14 and its respective stock 19 is shown. With the rotation of all four stocks and their respective planes, a powerful diving moment is placed upon the stern of the submarine for it to dive. Obviously, the opposite movement of the diving operating rod 28 will cause the submarine to rise. Here it is to be noted that during the diving maneuvers inner gimbal ring 38 remains within the plane of the outer gimbal ring 34 so that no steering motions are created. Should, however, it be desirable to produce both diving and turning of the submarine, FIG. 6 illustrates the positioning of the gimbal ring assembly 30 with its outer gimbal ring 34 and the inner gimbal ring 38 along with each of the planes 12 , 14 , 11 and 13 to create a diving turn of the submarine. To effect such a diving turn, the diving operating rod 28 operates in a manner as described for FIG. 4 to tilt or rotate the outer gimbal ring 34 about its horizontal axis, however, at the same time, steering operating rod 29 is retracted forwardly to produce a rotation of the inner gimbal ring 38 in a counter clockwise direction relative to its axis within the outer gimbal ring. This plural action produces movement of the stocks and their respective planes to the position shown in FIG. 6 . It should be noted that the steering movement illustrated in FIG. 6 is the opposite of that represented by the turn illustrated in FIG. 5 . This should be apparent from the relative positions of the end of the steering operating rod 29 when viewed in each of the FIGS. 5 and 6. It should be understood that the diving operating rod 28 and the steering operating rod 29 could be actuated by ordinary double acting hydraulic cylinders, one for each operating rod or by any other means conventional in the art. It is important to understand that a feature of this invention is that all four planes or controlled surfaces 12 , 14 , 11 and 13 produce both steering and rise or dive moments simultaneously. The four planes are not activated independently but act together. In a military vessel such as a submarine, it is significant that all the controlled surfaces or planes are connected by the mechanism described above so that it is much less likely that any single plane, through equipment malfunction or damage could produce moments that would unpredictably negate or reinforce those of the other surfaces. It is also to be noted that the control system described for this invention is simpler and less complex than in a submarine using separate control rods for each plane or controlled surface. It is important to understand that the scope of the invention described above is only to be limited by the scope of the following claims.

A direction control assembly for a vehicle, particularly a submarine, travelling through and below the surface of a fluid medium such as the sea. The vehicle has a body formed with a main axis running fore and aft, a contoured outer surface forming flow lines with the fluid medium and a plurality of planes movably secured relative to and extending out from said surface for contact with the fluid medium to permit and produce rising, diving or turning procedures. A movement control assembly including inner and outer gimbal rings are mounted within the body for selective mutual as well as independent movement. A first operating rod is connected to the outer ring for controlling the mutual movement of both the rings and a second operating rod is connected to the inner ring for moving the inner ring independently of the outer ring. Individual connectors or stock rods are positioned between a selected ring such as the inner ring 38 and each of the planes for moving the planes according to the movement of the selected ring whereby selected movements of either or both of the rings move the planes for directing the travel of the vehicle.

TECHNICAL FIELD OF THE INVENTION This invention relates to roof vents, and more particularly to a novel roof vent designed for placement on the ridge of a roof to allow ventilation of the attic space below the roof. BACKGROUND OF THE INVENTION A variety of designs exist for roof vents. Recently, the use of a "ridge type" vent has become popular. That type of design reduces the number of roof penetrations necessary to achieve adequate venting. Also, it allows placement of the vent at the upper reaches of the attic space, thus enhancing the exit of any warmed air which may tend to accumulate in the attic space below the roof. Unfortunately, many of the vent designs currently available for such ridge type service are unduly complex to manufacture. Further, many of the heretofore available designs known to us take up an undesirable volume for shipment. Many of the ridge type vent designs currently available do not provide what I consider to be an adequate system of barriers against windblown debris, insects, or vermin. Therefore, a continuing demand exists for a simple, and inexpensive ridge type roof vent. More particularly, there exists a demand for a ridge type roof vent which has reduced shipping volume, and which provides a good barrier for protection against debris, insects, and vermin. Moreover, significant improvements can still be made in the design of a ridge type vent that can be inexpensively produced, easily stored and shipped, which provides a good debris barrier, and which can be installed with minimal training and expense by unskilled or semi-skilled workmen. Many roof vents of the character described above which provide the general capabilities desired have heretofore been proposed. Those of which I am aware are disclosed in U.S. Pat. Nos.: 4,924,761, issued May 15, 1990 to MacLeod et al. for ROOF VENT; 4,817,506, issued Apr. 4, 1989 to Cashmann for ROOF VENT; 4,643,080 issued Feb. 17, 1987 to Trostle et al. for ROOF RIDGE VENTILATOR SYSTEM; 4,642,958 issued Feb. 17, 1987 to Pewitt for VENTILATED WALL AND ROOFING SYSTEM; 4,545,291, issued Oct. 8, 1985 to Kutsch et al. for ROOFLINE VENTILATORS; 4,325,290 issued Apr. 20, 1982 to Wolfert for FILTERED ROOF RIDGE VENTILATOR; 4,280,399 issued Jul. 28, 1981 to Cunning for ROOF RIDGE VENTILATOR; 3,660,955 issued May 9, 1972 to Simon for STRUCTURE FOR PROVIDING AIR CIRCULATION AT THE ROOF OF A BUILDING; 3,236,170 issued Feb. 22, 1966 to Meyer et al. for VENTILATED ROOF CONSTRUCTION; 1,896,656 issued Feb. 7, 1933 to Anderson for ASSEMBLY OF METAL SURFACES; 1,785,682 issued Oct. 22, 1928 to Hamiliton for WINDOW VENTILATOR; West German Patent No. 3,320,850 issued December 1984 to CPMC; and West German Patent No. 36 15 015.0-25 issued December 1987 to Knoche. For the most part, the documents identified in the preceding paragraphs disclose devices which have one or more of the following shortcomings: (a) they are difficult or bulky to package, (b) their design is more complicated than is desirable, and as a result, (c) they are relatively expensive to manufacture. One of the most common deficiencies of the heretofore available roof vent designs of which I am aware, the relative complexity of the design, is primarily due to the type of airflow structure provided. Also, some designs, such as that shown in the MacLeod patent, require the insert of some barrier material to restrict the entry of insects and vermin. Such a barrier reduces venting efficiency and is also subject to becoming clogged or plugged over the life of the device, thus leading to reduced efficiency. Also, some prior art roof vents have gutter like projections from beneath the shingles which detracts from the visual appearance of the vent, as well as accumulates unwanted debris. Thus, the advantages of the compact, arched and visually pleasing, straight through airflow grille design of our easily manufactured roof vent are important and self-evident. SUMMARY OF THE INVENTION I have now invented, and disclose herein, a novel, improved roof vent which does not have the above-discussed drawbacks common to those somewhat similar products heretofore used of which I am aware. Unlike the roof vents heretofore available, our product is simple, lightweight, relatively inexpensive and easy to manufacture, and otherwise superior to those heretofore used or proposed. In addition, it provides a significant, demonstrated additional measure of additional protection against entry of unwanted debris, insects, and vermin when compared to many currently known designs. I have developed a novel roof vent for use on a ridge of a roof. The vent has a body portion with an upper wall portion and sidewalls at the ends thereof. Grille portions are hingedly located longitudinally along the lateral edges. Wedge shaped stiffening supports are provided above the grille to keep the grille from compressing upward against the underside wall of the roof vent. Likewise, in the preferred configuration, generally triangular shaped support wings are provided below the grille to prevent the grille from compressing downward against the roof. The grille is folded under the upper wall portion, so that the stiffening supports act as spacers between the underside wall of the vent and the grille, when the grille is placed into the operating position. The grille portions have at their distal end a set of flexible teeth adapted to fit on shingles and down between shingles in any gap therebetween, so as to prevent passage between the grille and the shingle of any debris, insects, or vermin. The grille portions have void defining structures therein adapted to receive therethrough a nail guide and support, which guide is suitable for locating a nail to affix the vent to a roof. The vent is manufactured in a flat configuration, and thus it is capable of being easily packed and shipped. When folded at the hinged bends for installation, the vent provides full venting capability while protecting against passage therethrough of unwanted debris, insects, or vermin. OBJECTS, ADVANTAGES, AND FEATURES OF THE INVENTION From the foregoing, it will be apparent to the reader that one important and primary object of the present invention resides in the provision of a novel, improved roof vent to provide ease of manufacture, shipping, storage, and installation. Other important but more specific objects of the invention reside in the provision of roof vent as described herein which: can be manufactured in a simple, straightforward manner; in conjunction with the preceding object, have the advantage that they can be configured by installation personnel to quickly establish an operating vent position; and which provides a vent which is fully protective from windblown debris, insects, and vermin; and which are designed so as to prevent compression of the vent downward against a roof; and which provide a means for safely and reliably coupling a series of vents to provide a roof wide vent while allowing for expansion and contraction of the vents. Other important objects, features, and additional advantages of our invention will become apparent to the reader from the foregoing and the appended claims and as the ensuing detailed description and discussion proceeds in conjunction with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING In the drawing: FIG. 1 is a perspective view of a roof ridge whereupon three roof vent panels according to the present invention are provided; a section of roof which has been prepared for receiving additional roof vent panels is also illustrated. FIG. 2 is a cross-sectional view of a roof vent in place on a roof, taken as if across line 2--2 of FIG. 6 below (note change in location at partial cutout); this view reveals the grille and vanes which allow air to vent from the attic space below the roof, and also the overlapping sidewalls which serve to stiffen and support the vent, as well as providing protection at the end panels against unwanted entry of debris, insects, and vermin. FIG. 3 is an end view of a roof vent, illustrating the folding action of the grille portions, and the stiffening supports adjacent thereto, as well as the end panels and nail guide supports; the roof vent is shown in solid lines before installation, and is shown below in hidden lines after placement on a roof. FIG. 4 is perspective view of a roof vent, showing the vent folded and bent into an operating position, ready for installation on a roof. FIG. 5 is a partial cut-away view of the grille portion at the lateral edges of a roof vent, showing in cross-sectional view a nail guide support and a companion oval shaped structure in the grille which defines an opening through which the nail guide support penetrates the grille to reach the roof below; also shown are the flexible teeth at the inner edge of the grille which are adapted to engage roofing shingles which may be located therebelow. FIG. 6 is a bottom view (looking upward) of a first embodiment of a roof vent, showing the inner portions and the grille portions in a flat, spread apart relationship. FIG. 6A is a cross sectional view taken across 6A--6A of FIG. 6, showing the height differential of various segments of the grille; this differential allows components of the grille to cooperate to with the tab receptable in order to provide adequate clearance with the tab receptacle when the vent is folded into its operating position. FIG. 7 is a view of opposite ends of two adjacent roof vents, taken as if through the lines 7a-7a and 7b-7b of FIG. 6, showing the method for joining adjacent roof vents during installation on a roof; here, the parts are shown before joining adjacent panels. FIG. 8 is a view similar to FIG. 7 of two adjacent roof vents, again showing portions taken as if through the lines 7a--7a and 7b--7b of FIG. 6, but now showing the adjacent roof vents joined by interlocking parts. FIG. 9 is a perspective view of the roof vent of the present invention, now employed by bending the panels into a configuration for a clerestory installation. FIG. 10 is a cross-sectional view of a roof with roof vent in place; this view reveals the grille and vanes which allow air to vent from the attic space below the roof, and also the overlapping sidewalls which serve to stiffen and support the vent, as well as providing protection at the end panels against unwanted entry of debris, insects, and vermin. FIG. 11 is a bottom view (looking upward) of a second embodiment of a roof vent, showing the inner portions and the grille portions in a flat, spread apart relationship. FIG. 12 is a top view (looking downward) of the second embodiment of a roof vent just illustrated in FIG. 11; this view is identical for the roof vent illustrated in FIG. 6 above. FIG. 13 is a vertical cross sectional view of the second embodiment of a roof vent, showing the vent in operation on a roof. FIG. 14 is a bottom view (looking upward) of the second embodiment of a roof vent as illustrated in FIGS. 11 and 12 above, but showing how two adjacent roof panels are interlocked. FIG. 15 is a perspective view, looking upward at a pair of roof vents, with the vents folded into their operational position, and showing where the vents have been permanently joined together for ease of installation of a long roof vent section. DETAILED DESCRIPTION OF THE INVENTION Attention is directed to FIG. 1, where there is shown a roof portion 10 of a building 12. The roof portion 10 has a ridge section 14 where a gap G indicated by arrows 15 exists between a first roof section 16 and a second roof section 18. Seen in the gap G are roof support trusses 20. The roof portion 10 is shown having a decking (see FIG. 2 below) covered with shingles 22. The shingles 22 may be of the kind having locating slots 24 therein. A series of roof vents 26 are provided above the gap G at ridge section 14; the vents 26 are configured to span the gap G between the first roof section 16 and the second roof section 18. As can be more readily seen in FIG. 2, roof portion 10 has a roof deck 30 (generally particle board or plywood), which is supported by trusses 20. Shingles 22 are provided above deck 30, usually in interlocking fashion as illustrated in FIGS. 1 and 2, if composition type shingles are utilized. Below the roof deck 30 is a space 32, normally enclosed so as to form an attic or ventilation space. It is usually necessary and desirable to remove air from space 32 to provide proper ventilation, so as to effect heat reduction in summer and moisture removal in winter. This is accomplished by allowing the hot or moisture laden air in space 32 to move upward in the direction of arrow 34 through gap G. Then, the air turns outward as indicated by arrow 36, thence down through grille 38 and outward to the atmosphere as indicated by arrows 39. The grille 38 is adapted to prevent the passage of solids above a preselected critical size from passage therethrough. FIG. 2 is a vertical cross-sectional view, taken along the line 2--2 of FIG. 6 below, and including an offset for the area shown in cutout in this FIG. 2. In FIG. 2, roof vent 26 is shown in its installed position above gap G of roof 10. Vent 26 is provided with a reinforcing portion 40 running longitudinally along the upper side of vent 26. The reinforcing portion 40 overlays the related cutout portion 41 also running longitudinally along the underside of vent 26 (see FIG. 3 for further detail). The cutout portion 41 provides a reduced thickness at the joint between the first and second inner integral planar body portions (AA and BB respectively) on either side of the vent 26, so that panels AA and BB can easily bend downward laterally along cutout portion 41. Flexible bend or hinge 42 is provided between a first outer planar body portion 43 of vent 26 and the grille 38. This bend 42 is preferably provided in sufficient thickness so that it tends to urge the grille 38 downward toward shingles 22. The distal end 45 of the grille 38 has molded therewith and extending therefrom teeth 46 and 48 which either are compressed upward (teeth 46) against the upper shingle 52 at its upper surface 50, or are extended (teeth 48) into gap 24 and thence downward against the lower shingle 22 at the upper surface 54 thereof. On the laterally opposing side of vent 26, a second outer planar body portion 55 is similarly provided; it connects laterally inward with panel BB and outwardly with a similar grille, as seen for example in FIGS. 3 or 6 below. Vent 26 is secured against roof 10 by way of nails 56 which are driven into roof deck 30. It can be seen that vent 26 is provided with interfitting sidewall portions 60 and 62, which come together below the bend at the center reinforcing portion 40 and cutout portion 41, so as to minimize the formation of any gap between sidewalls 60 and 62. Extending outwardly laterally along the male end M of the roof vent 26, additional sidewall portions 64 provide both end barriers and support for the vent 26. These sidewall portions 60, 62, 64, provide adequate vertical spacing of the vent 26 above the upper surface 50 of shingle 52. Also, the sidewall portions 64 provide extra strength in the case that additional shingles, similar to those identified as 22 and 52, are affixed above vent 26 by nailing therethrough. Similar sidewall support portions are provided on the female end F of vent 26, as shown in FIG. 6 below. Turning now to FIG. 3, a side view of the roof vent 26 is provided to show "before" and "after" configurations during preparation for installation. At the top of FIG. 3, a vent 26 is shown in a flat configuration, ready to bend into shape for affixing to the roof 10. Here, the male end M of the vent 26 is shown, and thus tabs 68 are seen extending from the male end M of the vent 26. To place the vent 26 into an operating position, both grilles 38 are turned under the underside wall 44 of the vent 26 at hinges 42, which are located at the lateral edges 71 of the vent 26. For example, the first grille 38 at the left of FIG. 3 is shown being turned inward and upward in the direction of reference arrows I in a hinged fashion at hinge 42, so as to place the grille 38 into its operating position illustrated immediately below. Then, the vent 26 is bent inward and downward along reinforcing portion 40 and cutout portion 41 at the center of the vent 26, so that the opposing lateral edges 71 of vent 26 are turned inward and downward somewhat toward each other. Where necessary, additional inward bending can be accomplished at longitudinal cutout portions 72 and 74, located on opposing sides of the vent. The bend at the center along portions 40 and 41, as well as the adjacent bends along cutout portions 72 and 74, are particularly helpful in aligning the vent along the center C of the gap G along the roof 10 ridge. Sidewall supports 60, 62, 64 and 84, well as nail guides 76, support the vent 26 above shingles 22 and 52, thereby preventing the underside wall 44 of vent 26 from compressing downward against the shingles 22 and 52. An important feature of this roof vent 26 are the wedge shaped stiffening supports 78, which are provided in sets located transversely in a spaced apart relationship along grille portions 38. This feature is continued at nail guides 76 by use of shortened companion support posts 79, which are located adjacent to nail guides 76. The stiffening supports 78 and support posts 79 provide the necessary strength uniformly to support roof vent 26 above roof 10. Preferably, sidewall supports 60, 62, 64, and 84 are of a height E, and the wedge shaped supports 78 are of a height H, where H is slightly less than E (when both are measured to a common datum such as underside wall 44) such that when wedge shaped supports 78 are interposed below the underside wall 44 of vent 26, the wedge supports fit firmly between the wall 101 and the grille 38 therebelow, so as to provide a relatively uniform spacing for air passage through grille 38. The offset between interfitting sidewall portions 62 and 60 may be better seen in FIG. 4 and 6. When the vent 26 is bent inward and downward toward in an installation configuration as is illustrated in FIG. 4, at the female end F, sidewall 60 fits between sidewall 62 and interior tab 80. Likewise, sidewall 64 fits between sidewall 60 and interior tab 82. Also, sidewall 84 fits between sidewall 62 and interior tab 86. To accomplish the described interfitting between sidewalls, an offset 88 is provided to realign a particular sidewall to the center line of a space 90 between an opposing sidewall and an interior tab. This space 90 should be provided in a width W to closely accommodate the width of the interfitting sidewall to be placed between the interior tab and the opposing sidewall, as just described above, without any substantial gap therebetween. For example the width W of space 90 between sidewall 60 and tab 82 is only slightly wider than the width (along longitudinal direction of vent 26) of the interfitting sidewall 64. The vent 26 is provided in any convenient length L; for most U.S. construction sites, this length is four (4) feet, although lengths L of two (2) feet may be desirable in some cases. Grilles 38 are shortened for clearance around sidewalls 64 and 84 by a length X at the male end M of vent 26. Likewise, grilles 38 are shortened by a length Y around receptacles 92 at female end F of vent 26. I have found it convenient to use a length X of about 1/8 of an inch, and a length Y of about 5/8 of an inch. As shown in FIG. 6A, it is important to note that at the female end F of vent 26, the grilles 38 have a reduced height R at grille portion 93 to allow the grille 38 to easily fold inwardly. More importantly, a reduced height R' is provided at the lateral edge of grille 38 with respect to grille portion 94, so that when the grille 38 is folded into the operating position, clearance is provided between grille portion 94 of grille 38 and receptacles 92. I find that a height of R and R' of about 1/8 inch or slightly less is desirable. Grille portions 95 and 96 are normally twice or slightly more of the thickness of the grille portions 93 and 94. I prefer to use this technique to allow the grille to be closely placed with recepticles 92, in order to avoid inteference of the receptacles with the folding and bending of the vent 26, and accompanying interfetting sidewalls described above. Returning now to FIG. 5, a cutaway view of nail guide 76 is provided. The guide 76 is provided with sufficient structural strength to prevent compression of the grille downward thereabout when a nail is placed therethrough. To closely fit nail guide 76 through grille 38, the grille 38 accommodates nail guide 76 therethrough by way of void space defined by grille guide sidewalls 97, which may be convenient to provide in an oval shape. Fill-in plane 98 hels to snugly fit grille 38 against nail guide 76. This filled in surface 98 provides a partial seal between the longitudinal end portions 97 F and 97 M of the sidewalls 97, and inward up to the operating position of nail guide 76, so as to minimize the open space left behind upon installation of the vent 26. Fill-in plane 98 is ideally about as thick as grille portions 93 and 94. To help secure nail guide 76 during assembly, a tip T may be provided at the front of grille guide sidewall 97, to frictionally engage the downwardly extending generally tubular shaped wall S of nail guide 76 to prevent outward slippage of the grille portion 38. The nail guide 76 may be provided with a small chamfered entry 99 for nail 56, when desirable. The entry 99 is preferably has a smaller diameter D than the diameter N of nail 56. As noted above, support post 79 is provided to properly space grille 38 above the underside wall 44 of vent 26, so as to keep roof vent 26 from collapsing inwardly. The grille 38 also includes a series of substantially vertical vanes 100 running longitudinally along vent 26. The vanes 100 are spaced apart and strengthened by transverse running support segments 102. At the distal end 45 of grille 38, flexible tabs 48 are provided (also noted above as tabs 46 above when in a deformed position above a shingle 52). Attention is now directed to FIGS. 7 and 8. In order to securely interlock a series of roof vents 26 located on a roof structure 10, tabs 68 are provided at male end M, sized for snugly inserting in receptacles 92 at female end F. As shown, the female end F of a first vent 26A fits down over male end M of a second vent 26B. Receptacle 92 fits around tab 68. The section shown for first vent 26A is as if taken through line 7b--7b of FIG. 6. The section shown for second vent 26B is as if taken through line 7a--7a of FIG. 6. An overhanging edge 106 of vent 26A extends above the top 108 of tab 68 on vent 26B, and thus covers the male end M of vent 26B. The overhangings edge 106 causes the ends of the vents 26A and 26B to overlap, thereby forming a continuous ridge type vent along the roof ridge of a structure upon which it has been placed. My interlocking roof vent feature is clearly seen in FIG. 8, where the vents 26A and 26B are shown joined together in their operative position. In particular, note the vertically offset (lowered) generally U-shaped gutter 109 which is provided between tab 68 and the top of vent 26B, which tends to prevent moisture from escaping through the joint between vents 26A and 26B toward the roof 10 below. FIG. 9 illustrates the alternative use of the vent 26 in clerestory applications. In such installations, vent 26 is bent backwards at reinforcing 40 and cutout portion 41, into a generally L-shaped configuration. In such configuration, the space 110 is vented outward in the direction of arrows 112. Attention is now directed to FIG. 10, where a second embodiment of my novel ridge top vent for roofs is shown in a partial cross-sectional view. To the extent feasible, similar features will be identified by using the same reference numerals as already described hereinabove, without further mention thereof. In this FIG. 10, vent 120 is shown in place on a roof 10, similar to the configuration shown in FIG. 2 above. Here, additional support posts 122 are provided beneath underside wall 44. Posts 122 fit down to shingles 52, to support vent 120 to prevent it from sagging downward. For added strength, posts 122 may be provided with a thickened center portion 123. In addition, support wings 124 are provided below grille 38. For best support, support wings 124 are preferably provided in a generally triangular shape extending vertically downward below grille 38 and inward toward the centerline of the roof. The support wings 124 achieve maximum effect when a foot 125 is provided in a shape adapted to extend laterally along the roof and fit the contour of shingles 54. Preferably, support wings 124 are integrally molded to the grille portion 38. More preferably, the support wings 124 are lower extensions of the earlier noted internal stiffening supports 78. Support wings 124, in cooperation with the stiffening supports 78 (see FIG. 13 below) securely position grille 38 between the roof shingles 52 and the underside wall 44 of vent 120. FIG. 11 shows the underside of vent 120 in the unfolded, spreadout, manufacturing position. Support posts 122 with their thickened central sections 123 are clearly visible. As the support wings 124 are under the grille, they are not seen in this FIG. 11, but may be seen in the top plan view of similar vent 130 depicted in FIG. 12. A third embodiment vent 130 shown in FIG. 12 is similar to vent 120 shown in FIG. 11, but has been modified to show a neutral end N configuration; this type of end would normally be used at the end of a chain of vents (rather than to join it to an adjacent section) and is typically found at the edge of the roof. Clearly seen running longitudinally at the center of the vent 130 is reinforcing portion 40. Laterally spaced apart from the reinforcing portion 40 are fold lines 132, corresponding to cutout portion 72 of similar vent 26 seen in FIG. 11. Likewise, reinforcing portion 134 corresponds to cutout portion 74 seen in the similar vent 26 in FIG. 11. Vents 120 and 130 are preferably provided with wedge shaped stiffening supports 78 and support posts 79 as noted in the first embodiment vent 26 set forth above. Also, nail guides 76 fit through grille guide sidewalls 97 which define and opening through grille 38, all as more particularly described above. Turning now to FIG. 13, a cross-sectional view of vent 120 is provided. The cross-sectional view of vent 130 is similar. In this view, the position of stiffening supports 78 above grille 38 and below wall 44 is evident. Also, support wings 124 are seen provided below grille 38 in a position to support the wings above the roof shingle 52. In addition, support posts 122 are shown providing additional support to vent 120 to support it above the shingles 52. My interlocking mechanism provided for vents is illustrated in FIG. 14, which shows a bottom view (looking upward) of joined male M and female F ends of vent 120. Tabs 68 are shown affixed in receptacles 92. At the female end F, grille 38 is provided with an outwardly extending portion 140 of offset length Y and lateral width reduction U which allows the grille 38 to be folded inward yet avoid inteference with receptacles 92. At the male end M, the grille 38 is provided with an inset portion 142 of inward length X and lateral width reduction V. Inset portion 142 is sized to avoid inteference with gutter 109, which, as noted in FIG. 8 above, extends downward from underside wall 44 and laterally inward for a short distance. Also shown in FIG. 14, as well as FIG. 15, are optional fasteners 150 such as rivets which can be used to join pairs of vents 150 in order to speed installation of the same. For example, a pair of two (2) foot length vents can be used together and joined to provide a four (4) foot roof vent. In FIG. 15, the interlocking nature of the sidewall portions is shown in mirror image of the design shown in FIG. 14; clearly, the concept is reversable. In FIG. 15, it is clear that interfitting sidewall portion 62 fits between the spread apart walls 152 of sidewall 60 at the first end 154 of sidewall 62. Likewise, sidewall portion 62 fits between the spread apart walls 156 of sidewall 84 at the second end 158 of sidewall 62. The interior tab pairs 80 (at the first end 154 of sidewall 62) and the tab pairs 86 (at the second end 156 of sidewall 84) provide additional stability by slightly compressing walls 152 and 156, respectively, against sidewall 62. Similarly, a first end 160 of sidewall 60 fits between spread apart walls 162 of sidewall 64. Stability of that joint is provided by interior tabs 82. Therefore, it is to be appreciated that the roof vent provided by way of the present invention is a significant improvement in the state of the art of ridge type roof vents. My vent is lightweight, being normally manufactured of polypropylene or polyethylene, and is capable of being easily packaged and shipped without taking up undue space. It will be readily apparent to the reader that the present invention may be easily adapted to other embodiments incorporating the concepts taught herein and that the present figures are shown by way of example only and not in any way a limitation. Thus, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalences of the claims are therefore intended to be embraced therein.

A ridge type roof vent. A roof vent is provided for use on a ridge of a roof. The vent has grillee portions flexibly located longitudinally along the lateral edges. The grille portions have at their distal end a set of flexible teeth adapted to fit on shingles and down between shingles in the gaps therebetween, so as to prevent passage between the grille and the shingle of any debris, insects, or vermin. The grille portions have void defining structures therein adapted to receive therethrough a nail guide and support, which guide is suitable for locating a nail to affix the vent to a roof. The vent is manufactured in a flat configuration, and thus it is capable of being easily packed and shipped. When folded at the hinged bends by the installer, the vent provides full venting capability while protecting against passage therethrough of unwanted debris, insects, or vermin.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application 60/699,272 entitled “A Software Program for Managing Drop Rate of a Windrower Header” filed on Jul. 26, 2005, in the name of the same entity as the present application. BACKGROUND OF THE INVENTION [0002] The present invention relates to a control for managing the drop rate of a header on an agricultural implement and, more particularly, to such a control for the header on a windrower header. [0003] Regulating the positioning of headers on agricultural harvesters using hydraulic and electro-hydraulic control systems is generally known in the industry, as shown in U.S. Pat. No. 6,901,729. The '729 patent describes a header flotation system which is referred to as “non-independent” in that each side of the header is supported by a single hydraulic cylinder, which perform both the flotation and lift functions. To accommodate unbalanced headers (center of gravity not centered between the lift arms), hydraulic oil is sent to the return side of the lift cylinder on the lighter side of the header, thus resulting in even raising, lowering and float. [0004] It is not uncommon to use different headers for different crops or crop conditions on the same tractor unit, i.e., to change headers depending upon harvesting conditions. Different headers cause different drop rates owing to obvious variables such as weight, condition and type of seals, system friction, geometries, aperture sizes, and the like. The interchangeability of headers and the incumbent changes in drop rate often results in inefficient drop rates. [0005] Thus, it would be desirable, beneficial and advantageous to have a control system that may be “tuned” to the particular combination of header and tractor unit, thus maximizing operation efficiency and operator comfort. SUMMARY OF THE INVENTION [0006] Accordingly, it is an object of the present invention to provide an improved control arrangement for a header lift system that compensates for the above-noted disadvantages. [0007] It is another object of the present invention to provide a method of tuning the drop rate of a header as required to maximize efficiency and operator comfort. [0008] It is a further object of the present invention to provide a control system for adjusting the drop rate of a header in an agricultural harvesting implement. [0009] It is a still further object of the present invention to provide a control system for adjusting the drop rate of a header that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use. [0010] These and other objects are achieved by providing a method for controlling and modifying the drop rate of a header on an agricultural harvesting machine. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: [0012] FIG. 1 a is a partial side elevational view of a crop harvesting machine of the type with which the invention may be used, also showing a simplified side view of the lift and flotation system; [0013] FIG. 1 b is a rear elevational view of a multifunctional handle of the general type with which the present invention may be used; [0014] FIG. 2 is a schematic view of one embodiment of an exemplary hydraulic system; [0015] FIG. 3 is a schematic of exemplary hydraulic, mechanical and electrical subsystems that cooperate to produce the system of FIGS. 1 and 2 ; and [0016] FIGS. 4 a - 4 e are various depictions of visual outputs on a display unit. DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail. [0018] FIG. 1 a shows a self-propelled windrower 10 of the type with which the instant invention may be advantageously utilized. More specifically, the figures illustrate what is referred to as a “non-independent” flotation system such as shown in U.S. Pat. No. 6,901,729—the present invention works quite well with such a system. It will, however, be appreciated that the principles of the present invention are not limited in use to this particular machine, but may be used on many other harvesting machines with headers and with different flotation systems, such as the “dependent” flotation system shown in co-pending U.S. patent application Ser. No. 10/822,465. [0019] In the illustrated embodiment, the self-propelled windrower 10 comprises a tractor 12 and a header 14 , the header 14 being attached to the front end of the frame 16 or chassis of the tractor 12 . The header may be of generally any suitable construction or design, and may include not only crop-harvesting mechanisms, but also crop conditioners such as elongate rolls 15 . Such attachment of the header 14 to the frame 16 is achieved through a pair of lower arms 18 (only the left one being shown, the right being generally the same) pivoted at one end to the frame 16 and at the other end to the header 14 , as well as through a central upper link 20 . The link 20 may take the form of a single double-acting hydraulic cylinder 21 whose extension and retraction is adjusted by the operator to remotely control the angle of the sickle bar 22 on the lower front of the header 14 . [0020] A single lift/flotation cylinder 24 , interconnecting the lower arm 18 and the frame 16 supports each side of the header, i.e., each side of the header is supported by its own lift/flotation cylinder (again, only the left one being shown in FIG. 1 a ). More particularly, the control system accomplishes a single control function, i.e. the lift/flotation cylinders. It is, at this point, useful to understand that within the operator's cab of windrower 10 there is located a multifunction handle (“MFH”), such as shown as element 54 in FIG. 1 b , to function as part of the overall implement control system. MFH 54 may be located within or closely adjacent to the console, in a convenient position to the operator's right hand, and may serve as the operator's input to control and manage direction and speed of travel, header height, reel speed, raise and drop rates, various inputs to controller 50 , and the like. The MFH shown is similar to that shown in more detail in U.S. Pat. No. 6,148,593, issued to Heinsey et al. on Nov. 21, 2000. The MFH of FIG. 1 b would necessarily have at the very least, a switching device, such as rocker switch 55 to move a cursor up and down a list of menu items on a display, plus at least one selection button, such as switch 57 . [0021] Directing attention now to FIG. 2 , the hydraulic control system for left cylinder 24 and right cylinder 26 can be seen to include an electro-hydraulic subsystem generally depicted as 30 . For convenience of assembly and operation, the majority of the components may be housed in a single valve body 34 with appropriately located ports and other necessary connection devices and fixtures. A fixed displacement pump 36 moves the hydraulic fluid into subsystem 30 from reservoir 40 , through the various circuits as directed by control valves, to a single accumulator 42 , to hydraulic cylinders 24 , 26 and back to reservoir 40 as appropriate. [0022] While FIG. 2 should be readily understood by one of skill in the art, it is helpful to broadly identify the various components in more detail. A PRV (pressure reducing valve) 44 operates as part of the hydraulic counterweight process, to be described further below. Element 39 is a master solenoid valve with an associated relief valve 43 . A PRV 44 for the lift/flotation and drop rate functions is in flow communication with the lower solenoid valve 46 , the raise solenoid valve 48 , and the float solenoid valve 49 . [0023] FIG. 3 provides a more detailed depiction of the complete control system and subsystems. The hydraulic system, as shown also in FIG. 2 , additionally depicts the electrical control and mechanical subsystems. Importantly, this figure depicts the multi-channel programmable controller 50 which exchanges electrical signals from the float switch 52 , the PWM (pulse width modulated) solenoid 56 associated with PRV 44 , the master valve 39 , and other valves to manage the lift and flotation functions as established by the operator through the appropriate switch and shown on display 64 . Also depicted in FIG. 3 is MFH 54 . [0024] The hydraulic cylinders, attached to respective ends of the header 14 , perform both the lift and flotation functions. The lifting and floating function is achieved by coupling the lifting end of the hydraulic cylinders to each other and then to a hydraulic pump, control manifold, and accumulator. The operator sets the desired flotation force by actuating a rocker switch located on the operator's console or the MFH. One switch position allows hydraulic oil to enter the accumulator (increasing the hydraulic pressure), which reduces the header contact force, or flotation force, with the ground. The other switch position allows oil to exit the accumulator (reducing the hydraulic pressure), which increases the header contact force with the ground. Once the flotation force is set, the control valves will return to this preset flotation condition whenever the float mode is selected, irrespective of subsequent header lift and lower operations. [0025] To accommodate unbalanced headers (the header center of gravity is not centered between the lift arms), hydraulic oil is applied to the return side of the lift cylinder on the lighter side of the header. The addition of a defined hydraulic pressure on the back side of the cylinder results in the same lifting pressure to be required for each side. The header will then raise, lower, and float evenly. The result is the same as changing the lift geometry or adding ballast to the header. This function is referred to as the “hydraulic counterweight”. [0026] Hydraulic oil is supplied from the hydraulic ground drive charge pump, which provides constant pressure any time the engine is running. To prevent cavitation of the charge pump during rapid changes in system volume, such as during the header lower cycle, makeup oil is supplied from the header lift pump. The operator sets the hydraulic counterweight by energizing valve 38 to apply more weight (hydraulic pressure) to the light side of the header until the header raises and lowers to a level condition. If too much weight is applied, the operator simply energizes the valve in the opposite direction. Once the correct setting is established, the hydraulic counterweight will not need to be readjusted during machine operation. Re-adjustment will only become necessary if the header builds up with debris or upon exchange with another header. [0027] For headers that experience severe changes in balance during normal operations, e.g., draper headers with deck-shift, an electro-hydraulic valve can be installed in place of the manual control valve. This electro-hydraulic valve is adjusted from a rocker switch on the operator's console or the MFH. The operator then sets the hydraulic counterweight for each deck position. Once these valves are established, the control valve will adjust automatically and the deck positions are selected. [0028] Referring to FIGS. 2 and 3 , to adjust or control the header drop rate to fit the header configuration and weight controller 50 manipulates the various components in a sequenced and timed manner as dictated by the programming within controller 50 . Taking the header lowering cycle to be four seconds (or very nearly four seconds), the starting time, i.e., where time=0.00, is the point at which the operator presses the switch to lower the header. This switch could be either on the console or on the MFH. Thereafter, the following sequence and steps take place: t=0.00 The hydraulic master valve 39 is energized to pressurize the system. PRV 44 is energized with a value equal to the flotation value plus the offset value (drop speed value). Relief valve 43 is set at approximately 3400 psi. t=0.33 Master valve 39 is maintained at 100%. PRV 44 current is maintained at value of flotation plus offset value. Lower solenoid valve 46 and float solenoid valve 49 are fully energized to lower the header through the PRV valve 44 . T=2.33 Master valve 39 is maintained at 100%. Current to PRV 44 is modified to equal flotation value only. Lower solenoid valve 46 and float solenoid valve 49 continue to be fully energized. t=3.83 Master valve 39 is maintained at 100%. Current to PRV 44 is maintained at flotation value. Lower solenoid valve 46 is deenergized to isolate the accumulator and lift cylinders from PRV valve 44 . Float solenoid valve 49 continues to be energized to keep the accumulators in the circuit with the hydraulic lift cylinders. t=4.08 Master valve 39 is deenergized, reducing pressure to zero. Current to PRV 44 is maintained at flotation value. Float solenoid valve 49 continues to be energized to keep the accumulators in the circuit with the header lift cylinders. [0050] In making the adjustments for different headers and drop rates, the only thing that changes, if the drop rate is something other than zero, is the current applied to PRV 44 . So, for the first two seconds, PRV 44 is energized with the current necessary for the flotation setting plus a small offset value for drop rate. Then, for the last two seconds, the PRV is energized with the current necessary for the flotation setting. If the drop rate is set at zero, there is no modification to the PRV current—it remains the same. [0051] The setup process for operation of the windrower includes a series of options that appear on the visual display at the command of the operator and through his manipulation of various input devices. The menu significant to the present invention is the Header Configuration menu, shown in FIG. 4 a . “Header Drop Speed” (“speed” and “rate” having the same meaning herein) is one of the menu items that may be selected by moving the cursor in any of a number of ways, as by manipulation of multi-position rocker switch 55 in FIG. 1 b . A particular menu item is then selected by another switch, such as switch 57 in FIG. 1 b (however, there are switches that can perform both functions, viz., cursor movement and item selection). When “Header Drop Speed” is selected, a second display appears, like FIG. 4 b , showing the presently set drop speed, in this example “−35”. By manipulation of either another switch that may, for example, show a “+” or “−” sign, the rate changes on the display. In this example, the value is changed in increments of 5, though this incremental amount is not significant so long as it is not so large as to make fine adjustment difficult. At the same time that the drop speed is changed, the display indicates whether the change is speeding or slowing the drop rate (see FIGS. 4 c and 4 d ). When the desired speed is reached, the cursor is moved to “Exit” and the selection is made to move on to further setup operations. The minus (−) sign shown on the display before the drop speed indicates a negative offset that is to be subtracted from the flotation set point. The lesser (algebraically smaller) the number, the lower the pressure, the faster the drop speed. If the number is preceded by a plus (+) sign, which indicates a positive offset that is added to the flotation set point, adjusting the pressure higher so that the drop speed would be slower. [0052] It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. For example, a touch screen visual display could be used, thus making the screen a primary input device. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the inventions.

A method for controlling and modifying the drop rate of a header on an agricultural harvesting machine by providing a programmable electronic control unit capable of receiving operator input through an input device. The programmable electronic control unit generates output signals based on the operator input to raise and lower the header according to a corresponding output drop rate signal.

BACKGROUND OF THE INVENTION This invention pertains to the art of coreless induction furnaces such as those that contain a replaceable refractory hearth lining, and more particularly to a method and system for extracting the lining from the furnace. The invention is particularly applicable to an induction melting furnace in which a furnace content to be heated is supported in a refractory hearth. Sometimes the lining material itself or the furnace content may be dangerous or harmful so that when it is necessary to replace the refractory lining, the lining should be contained for transport and ultimate disposal. The invention is particularly applicable to a method and system for extracting such a lining from the furnace and placement in a container for transport, storage or ultimate disposal. However, it will be appreciated by those skilled in the art that the invention could be readily adapted for use in other environments as, for example, where cumbersome and potentially harmful linings are to be replaced and contained upon extraction from a furnace or other device. Refractory linings that are employed as hearths useful for such induction melting furnaces are typically composed of fire-proof materials commonly referred to as dry ram type refractories such as silica, alumina or magnesia. The linings have to be replaced at regular intervals so the safety, convenience and efficiency of the replacement process are important considerations. In particular, where the furnace work content is a dangerous and harmful item, such as one that has been radioactively contaminated, minimal safety precautions require containment of the refractory lining during both extraction of the lining from the furnace and subsequent transport, storage and disposal. Prior known systems for refractory extraction and discharge have met with varying degrees of success. Such systems and methods have included lifting the refractory lining by means of a crane from the furnace cavity, dismantling of the furnace floor so that the lining can be pushed out or breaking up of the refractory lining with pneumatic hammers. U.S. Pat. No. 4,334,857 discloses a method and system where a push-out device, acting underneath the furnace floor, pushes out the furnace lining upon cooling of the lining so that a separation occurs between the furnace sidewalls and the lining. None of the foregoing prior art systems are useful with regard to the controlled extraction and containment of a dangerous lining material or a lining which has been contaminated by a harmful furnace content. All the methods will involve uncontained extraction and/or breaking up of the crucible. Also, the ejection device of the '857 patent involves a substantial modification of a furnace floor which is undesirable from the standpoint of furnace construction. The present invention contemplates a new and improved refractory extraction system and method which overcomes the above problems and provides improved safety and economy of construction and yet is simple in design so that refractory replacement can be easily accomplished while safe containment of a contaminated lining is maintained. BRIEF SUMMARY OF THE INVENTION In accordance with the present invention there is provided a furnace refractory extraction assembly including a coreless induction furnace having a selectively removable bottom portion. A refractory hearth lining is disposed within the furnace coils and has a bottom wall adjacent the removable bottom portion. A refractory extraction device is provided and includes an extractor shaft which can be attached to the removable bottom portion by insertion through the bottom wall of the refractory lining. The extraction device includes a piston and cylinder assembly to draw the bottom portion through the furnace whereby the refractory lining can be extracted from the furnace cavity. During normal operation, the extraction device is not used and a replaceable refractory plug is employed to assist in support of the refractory lining. In accordance with another aspect of the present invention, a container is disposed to receive the refractory lining upon extraction from the furnace. The container is clamped to the furnace during extraction. At the time of lining replacement, the refractory plug is removed to provide access to the bottom wall of the lining so that an opening can be made therethrough. The extractor shaft is then attached to the removable bottom portion. The other end of the extractor shaft is secured to the piston and cylinder assembly which, in turn, can draw the lining into the container. One benefit obtained by use of the present invention is an extraction system and method which can draw a refractory lining through a coreless induction furnace into a containment device. Another benefit obtained from the invention is a system and method for removing the lining from the furnace that involves minimal modification of a conventional coreless induction furnace bottom. A further benefit of the present invention is an extraction system and method that can be used for extraction and containment of a number of contaminated linings. Other benefits and advantages for the subject invention will become apparent to those skilled in the art upon a reading and understanding of this specification. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take physical form in certain parts and steps and arrangements of parts and steps, the preferred embodiments of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof and wherein: FIG. 1 is a cross-sectional view of a coreless induction furnace for normal operation formed in accordance with the present invention; FIG. 2 is an enlarged cross-sectional view of a portion of the furnace bottom of FIG. 1, particularly illustrating a refractory plug used in the furnace bottom during normal furnace operation; FIG. 3 is an enlarged cross-sectional view of another portion of the furnace bottom of FIG. 1, particularly illustrating the support of the furnace bottom at the sidewall of the furnace; FIG. 4 is a cross-sectional view of the furnace showing a container associated with the furnace open end and including an extraction device for drawing the refractory lining into the container wherein the refractory lining is shown in dotted line when positioned within the container; FIG. 5 is an enlarged cross-sectional view particularly showing the assembly of an extractor shaft associated with the container and the removable furnace bottom portion; and FIG. 6 is an enlarged cross-sectional view of the portion of the furnace bottom as assembled for lowering a new lining into the furnace. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein the showings are for purposes of illustrating the preferred embodiments of the invention only, and not for purposes of limiting same, the FIGURES show a coreless induction furnace 10 having steel shell sidewalls 12 in which are disposed a plurality of induction heating coils 13 spaced from the sidewalls 12 by an air gap 16, and a furnace bottom 14. Disposed within the furnace cavity is a refractory lining 20, preferably comprised of a dry ram type of refractory material such as silica, alumina, or magnesia. The lining 20 includes a bottom wall 22, sidewall 24, and a spout 26 at the furnace open end 28. The inner wall of the lining, referred to as the "hot face", is sintered, but the refractory material becomes looser and more granular as it moves away from the hot face. The outer sidewall of the lining engages a tapered grout layer 34 which with a layer of insulating material 44 forms a slip plane so that the lining 20 nests within the furnace in a manner that facilitates ease of removal. The furnace power coils 13 are supported by stud boards 30 and a conventional yoke assembly including a yoke 35, clamps 36 and bolts 37. The yoke assembly is insulated from the coils by an insulating layer 38. The furnace bottom is comprised of an assembly of several elements which are supported by a plurality of beams 40. It is a particular feature of the invention that a portion of the furnace bottom is separable and removable so that it can be withdrawn from the furnace bottom 14 toward the furnace open end 28 to cause the refractory lining 20 to be drawn through the furnace cavity. The bottom wall 22 of the refractory lining is adjacent to a cast bottom 42 of hard refractory material. The bottom wall 22 has a generally annular configuration and is sized to extend radially to immediately adjacent the layer slip plane 44 to provide a wide and evenly distributed support for the lining bottom wall 22. Adjacent the cast bottom 42 is annular plate 46, preferably aluminum, and steel plate 48. The aluminum plate 46 interrupts magnetic fields to the steel plate 48, which provides support for the cast bottom 42, particularly during its removal. The cast bottom 42 and plates 46, 48 comprise the removable portion of the furnace bottom which can be drawn towards the furnace open end to remove the refractory lining as will hereinafter be more fully explained. With reference to FIG. 3, it can be seen that the removable furnace bottom portion is supported by a bottom cover steel plate 50 . Another aluminum ring 52 also interrupts the magnetic fields to the plate 50. The coil turns 54 are supported by the stud boards 30 and stud bolts 60 which rest on an insulated block spacer 61. The coil turns 54 are spaced by gaps such as at 62 which are usually filled with grout. The gaps 63 between cast bottom 42 and grout layer 34 are typically also filled with refractory material at the time of assembly. Much of the above-described elements are conventional in assembly and configuration to accomplish an object and benefit of the invention that the subject furnace is intended to involve minimal structural modification of a conventional coreless induction furnace bottom. However, with reference to FIG. 2, a distinction can be seen in that the cast bottom 42 includes an opening 64 in the shape of a truncated cone to receive a refractory plug 66 therein which is matingly tapered to nest in the cast bottom 42. Over the plug 66 is a grout filler 69 of a refractory material, such as alumina plastic, to fill voids. The assembly for securing the plug 66 to the furnace bottom comprises an annular collar or pin guide 70, which abuts the plug 66 at its end 72. The pin guide 70 is, in turn, secured to the steel plate 48 by fasteners 74. A plate 76 covers the plug and pin guide 70. An annular spacer 78 is preferably employed to properly position the pin guide 70 relative to the steel plate 48. A bolt 82 is disposed through the plug 66 and plate 76 and is a part of the furnace ground detection system with wire connection 84. It can be appreciated that except for the opening 64 and the plug 66 and its associated support assembly, the furnace bottom would appear to a furnace operator to be very similar to a conventional furnace lacking the special refractory extraction system of the present invention. With particular reference to FIGS. 4 and 5, the special extractor system of the present invention will be more fully explained. The extraction system provides a means for removing the refractory hearth lining quickly, easily and as free of the normal dusty and dirty atmosphere normally associated with lining removal as possible for a safer containment operation. As shown in FIG. 4, the spout 26 (FIG. 1) is removed. Although apparently illustrated as rotated 90°, the furnace can be disposed in its normally upstanding position or rotated on its side as shown since the extraction system can be successfully employed in either case, or in any desired position. The refractory plug 66 and its support assembly has also been removed by loosening the fasteners 74 and one of the nuts holding the ground bolt 82 in place (FIG. 2). After removal of the plug 66, the pin guide 70 is refastened to the steel plate 48 (FIG. 5) along with new cover 77. The lining bottom wall 22 is now accessible through the cast bottom opening 64. An opening 90 is preferably drilled through the hearth refractory bottom wall 22 to accommodate an extractor shaft 92. Next, a lining extraction assembly 98 (FIG. 4) can be mounted on the furnace with conventional locking clamps and locator pin assemblies 100. The extraction device 98 essentially comprises a container 102 and a hydraulically powered piston and cylinder assembly 104 which has a rod 106 sized so that it can be extended into the furnace cavity and be secured to the extractor shaft 92. A spout closure chute 108 is disposed at the periphery of the container 102 and is lowered toward the furnace 10 to cover the refractory lining 20 at its end portion 110. Set screws (not shown) can be employed to tighten and hold the chute in proper position. The rod 106 is next extended its maximum length toward the extractor shaft 92. The shaft 92 is pressed through the bottom wall opening 90 until it centers with the rod so that it can be located and locked in the coupling 114. The shaft 92 is then threadedly secured to the coupling 114. It will be seen with particular reference to FIG. 5 that the shaft comprises a tube 116 and inner rod 118. Both of these elements are secured in the coupling 114, and then a nut is used to secure the other end of the shaft 92 to the steel plate 77, pin guide 70, spacer 78, steel plate 48 and aluminum plate 46. The entire assembly is next ready to be drawn from the furnace cavity to urge the lining 20 into the container 102. As can be seen with reference to FIG. 4, the container is shown holding the lining 20 and removable first bottom portion in dashed line. After the lining is fully drawn into the container, the hydraulics to the piston and cylinder assembly can be withdrawn, the container can be unclamped from the furnace and the lining can be removed to an appropriate disposal bin. While most of the lining will be removed by the extraction assembly 98, some of the loose backup will remain in the bottom of the furnace and will have to be raked and/or vacuumed out into a bin before a relining of the furnace can take place. After disposal of the lining 20, the removable bottom portion comprising plates 46, 48, pin guide 70, annular space 78, plate 76, and plug 66 can be lowered back into the furnace cavity by the lifting guide and threaded rod assembly 122 (FIG. 6). After insertion, a new lining can be disposed in the furnace cavity and the furnace can be returned to normal operation. It is a feature of the invention that with the use of the hydraulic piston and cylinder assembly associated with the container, the refractory lining can be drawn into the container without a need for substantially changing the furnace bottom to accommodate a permanent ejection device. Although a piston and cylinder assembly is shown, it is within the scope of the invention to employ other means for lifting the lining such as a hoist or winch. Also, the advantageous lifting action and structure could be employed without a container where lining containment is not necessary. The illustrations show a lifting action on the lining from above relative to the furnace bottom. It should be kept in mind that where the furnace is not upstanding, the "lifting" need not be in an upward direction, but rather only in a direction from above or opposite of the furnace bottom. The invention has been described with reference to preferred embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of the specification. It is our intention to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.

A furnace refractory extraction system and method includes a selectively removable bottom portion which is attached to a refractory extraction device associated with a container for drawing the refractory lining of a coreless induction furnace into the container. A plug portion in the furnace bottom is selectively removable to provide access to a bottom wall of the refractory lining. An opening is made in the bottom wall of the lining through which an extractor shaft is inserted and then attached to the removable bottom portion of the furnace bottom. The other end of the shaft is attached to a piston and cylinder assembly associated with the container at the open end of the furnace. When the piston and cylinder assembly is powered, the lining is drawn into the container.

FIELD OF THE INVENTION The present invention is generally directed to thermal ink jet printing. More particularly, the invention is directed to a method and apparatus for maintaining desired levels of heat energy transferred into ink to form ink droplets as characteristics of an ink jet print head change over its operational lifetime. BACKGROUND OF THE INVENTION Generally, thermal ink jet print head chips consist of several thin film layers, including a resistor layer, conductor layer, dielectric layer, and protection layer. When electrical current is passed through a resistive heating element formed in the resistor layer, ink adjacent to the heating element is superheated and forms a bubble that causes an ink droplet to be expelled from an adjacent nozzle. Many thermal ink jet print heads incorporate a tantalum aluminum (TaAl) thin film as the resistor layer in which the resistive heating elements are formed. Over time, a TaAl thin film experiences material degradation due to current and temperature stressing as electrical current pulses are applied to the heating elements. The material degradation mechanisms include aluminum segregation from the TaAl film, recrystallization of the TaAl under high temperatures, and electromigration of aluminum from the TaAl film. This degradation causes a gradual decrease in the electrical resistance of the heating elements over time. Many current ink jet printers apply one voltage level (rail voltage) to the resistive heating elements to pass electrical current through the elements, and this voltage level is not changed over the lifetime of a print head. With a constant rail voltage, any decrease in heating element resistance, such as by material degradation, causes a corresponding increase in the current flowing through the heating elements. An increase in current causes a corresponding increase in the heat energy generated by the heating elements, and an increase in the temperature at the surface of the heating elements. If surface temperatures rise too high, extensive ink kogation may occur at the surface of the heating elements. Also, increased current levels cause even greater electromigration or segregation of the aluminum in the TaAl film, which is further detrimental to heater reliability. Therefore, a system is needed for maintaining stable heat energy levels at the surfaces of the resistive heating elements over the operational lifetime of an ink jet print head. SUMMARY OF THE INVENTION The foregoing and other needs are met by a method of operating a thermal ink jet print head having nozzles through which ink is ejected when energy pulses having a desired pulse energy are applied to resistive heating elements associated with the nozzles. Each of the resistive heating elements has a heater resistance which tends to change over the operational lifetime of the print head. The method provides stable ink ejecting characteristics over the lifetime of the print head by compensating for the change in heater resistance. The method includes applying energy pulses having a first pulse width to the resistive heating elements, and counting the energy pulses to determine a pulse count. When the pulse count exceeds a threshold value, pulses having an adjusted pulse width are applied to the resistive heating elements, where the adjusted pulse width accounts for the changes in the heater resistance during the operational lifetime of the print head. Preferred embodiments of the method include accessing a total print head resistance value which is based at least in part upon the heater resistance and resistances of circuit components in series with the resistive heating elements, accessing a heater resistance value related to the heater resistance, accessing a print head voltage value, accessing a first pulse energy value related to the desired pulse energy, and determining the first pulse width based upon the heater resistance value, the total print head resistance value, the print head voltage value, and the first pulse energy value. Preferred embodiments further include accessing a second pulse energy value related to the desired pulse energy and determining the adjusted pulse width based upon the heater resistance value, the total print head resistance value, the print head voltage value, and the second pulse energy value. In another aspect, the invention provides a thermal ink jet printing apparatus for maintaining stable printing characteristics. The apparatus includes an ink jet print head having resistive heating elements for receiving electrical energy pulses having a voltage level and for transferring heat energy pulses having a desired energy level into adjacent ink based on the electrical energy pulses. The print head includes nozzles associated with the resistive heating elements through which droplets of the ink are ejected when the heat energy pulses are transferred into the ink. The apparatus further includes a printer controller in electrical communication with the print head. The printer controller determines a pulse count indicative of a number of electrical energy pulses, applies the electrical energy pulses having a first pulse width to the resistive heating elements when the pulse count is less than a threshold value, and applies the electrical energy pulses having an adjusted pulse width to the resistive heating elements when the pulse count exceeds the threshold value. The differences in the first and the adjusted pulse widths compensate for changes in the electrical resistance of the resistive heating elements over the operational lifetime of the print head. BRIEF DESCRIPTION OF THE DRAWINGS Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings, which are not to scale, wherein like reference characters designate like or similar elements throughout the several drawings as follows: FIG. 1 depicts a thermal ink jet print head according to a preferred embodiment of the invention; FIG. 2 is a functional block diagram of a thermal ink jet print head connected to a printer controller according to a preferred embodiment of the invention; FIG. 3 depicts the application of a rail voltage to print head resistances according to a preferred embodiment of the invention; FIGS. 4A and 4B depict a functional flow diagram of a preferred method for adjusting the pulse width of ink-firing pulses in an ink jet print head; and FIG. 5 depicts a functional flow diagram of an alternative method for adjusting the pulse width of ink-firing pulses in an ink jet print head. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 depicts an ink jet print head 10 , such as may be used in a thermal ink jet printer. The print head 10 includes an integrated circuit chip, also referred to herein as an ink jet heater chip 12 which, as described in more detail below, contains resistive heating elements, driver circuits, logic devices, and memory devices. An array of nozzles 14 are provided on the print head 10 through which droplets of ink are selectively ejected when corresponding heating elements in the heater chip 12 are activated. On the print head 10 are a set of electrical contacts 18 which make connection with a corresponding set of contacts in the printer when the print head 10 is installed in the printer. Electrical traces provided in the dashed-outline region 16 connect the contacts 18 to the heater chip 12 . Shown in FIG. 2 is a functional block diagram of the print head 10 connected to a printer 20 . Within the printer 20 is a microprocessor controller 22 that provides print control signals to the print head 10 based on print data from a host computer. The print control signals include a print head voltage signal, also referred to herein as a rail voltage, on the line 24 , and an encoded nozzle selection or address signal on the line 26 . Preferably, the rail voltage on the line 24 is provided as a pulsed signal, having a voltage amplitude in the 7-11 volt range, and having a pulse width in the 0.5 to 3.0 μs range. As described in more detail hereinafter, the invention sets the pulse width of the rail voltage pulses to provide an optimum energy density on the surface of the heating elements of the print head 10 . As depicted in FIG. 2, the line 24 provides the rail voltage to a driver 28 , such as a MOSFET device, which acts as a switch. The on/off state of the driver 28 is determined, at least in part, upon a selection signal from a selection logic circuit 29 . If the driver 28 is “on”, a current I i flows through a heating element 30 and through the driver 28 which is in series with the heating element 30 . The heating element 30 of the preferred embodiment is constructed from a tantalum aluminum (TaAl) thin film, and has an electrical resistance referred to herein as R H . Due to the resistance R H , the current I i flowing through the heating element 30 generates heat energy on the surface of the heating element 30 . This heat energy is transferred into ink adjacent the heating element 30 , thereby causing the ink to nucleate and force a droplet of ink outward through an associated one of the nozzles in the nozzle array 14 . The number of drivers and heating elements on a heater chip of a print head is typically in the hundreds. However, to avoid unduly complicating FIG. 2, only one driver 28 and one heating element 30 are depicted. One skilled in the art will appreciate that the present invention is applicable to a print head having any number of heating elements. The driver 28 , the line 24 , and the contacts 18 introduce resistance in series with the heating element 30 . This series resistance, as depicted in FIG. 3, is referred to herein as R s . The sum of R s and R H is referred to herein as the total resistance R T . The current I i flowing through the heating element 30 is expressed as: I i = V R T ,    where     V     is     the     rail     voltage . ( 1 ) The heat energy at the surface of the heating element 30 produced by a pulse of the current I i may be expressed as: E p =T p ×I i 2 ×R H ,  (2) where E p is the heat energy produced by the current pulse and T p is the pulse width. This relationship may also be expressed as: E p = T p × ( V R T ) 2 × R H = T p × ( V R H + R S ) 2 × R H . ( 3 ) As equation (3) indicates, if the resistance R H were to decrease over time, such as due to material degradation of the TaAl thin film, the pulse heat energy E p would increase. During design of the print head 10 , the resistance R H , the voltage V, and the pulse width T p are set to provide an optimum energy density on the surface of the heating element 30 . This optimum energy density is preferably high enough to cause nucleation of the ink to form an ink droplet moving at a desired velocity, but not so high as to cause kogation, or scalding, of the ink at the surface of the heating element 30 . Significant kogation impedes heat transfer and causes degradation in print quality. Thus, a significant decrease in the resistance R H leads to degradation in print quality if no compensation is provided to reduce the energy density at the surface of the heating element 30 . As discussed in more detail hereinafter, the present invention provides this needed compensation by adjusting the pulse width T p to account for changes in the resistance R H over time. As shown in FIG. 2, the print head 10 includes a nonvolatile memory device 32 , such as an EEPROM device, for storing values related to the pulse width T p . In the preferred embodiment of the invention, the memory device 32 stores a value for the rail voltage V, a value for the initial heater resistance R H , a value for the total resistance R T , a value for a pulse count, a value for a pulse count threshold, and values related to an initial pulse energy E 1 and an adjusted pulse energy E 2 . As described below, the controller 22 accesses the memory device 32 to retrieve one or more of these values, and calculates an optimum pulse width based thereon. Depicted in FIGS. 4A and 4B is a process for implementing a one-time adjustment in the pulse width T p to compensate for changes in the resistance R H over the operational lifetime of the ink jet print head 10 . The process is preferably begun during the manufacture of the ink jet print head 10 by recording in the memory device 32 the values related to print head characteristics which will be used in determining an optimum pulse width for the ink-firing pulses (step 100 ). In the preferred embodiment, these values include the rail voltage V, the initial heater resistance R H , and the total resistance R T , each of which is preferably measured during testing stages of the print head assembly process. Predetermined values related to the initial pulse energy E 1 and the adjusted pulse energy E 2 are also stored in the memory device 32 . The initial pulse energy value E, represents the desired value of heat energy generated by the heating element 30 . The adjusted pulse energy value E 2 represents a change in energy to account for the expected change in heating element resistance R H after a predetermined number of firing pulses. In the preferred embodiment, the process for adjusting the pulse width is carried out when the printer 20 is powered on, when a print head maintenance routine is performed, or when a new print head 10 is installed in the printer 20 . If any one of these events occurs (step 102 ), the printer controller 22 accesses the rail voltage value V and the total resistance value R T from the print head memory device 32 (step 104 ), and calculates the initial current value I i , preferably based on equation (1) (step 106 ). During the operational lifetime of the print head 10 , a running count is kept of the number of ink-firing pulses generated by the print head 10 . Preferably, since this pulse count value is associated with a particular print head 10 , it is stored in the print head memory device 32 . Alternatively, the pulse count value may be stored in memory in the printer 20 . The controller 22 accesses the pulse count value and determines based thereon how many ink-firing pulses have been generated by the installed print head 10 (step 108 ). The subsequent steps in the process are determined by whether the pulse count exceeds a predetermined threshold value. Experiments conducted on a particular print head manufactured by the assignee of this invention have indicated that about 50% of the reduction in the heating element resistance R H due to thin film material degradation occurs prior to the pulse count reaching about 7.5 million. Thus, in the most preferred embodiment of the invention, the threshold value is about 7.5 million. However, it should be appreciated that the rate of change in heating element resistance R H may vary from one print head design to the next, such that different threshold values may be selected based upon characteristics that vary from one print head design to the next. Thus, it should be appreciated that the invention is not limited to any particular threshold value. As depicted in FIGS. 4A and 4B, if the controller 22 determines that the pulse count value is less than the threshold value (step 110 ), the controller 22 accesses the heating element resistance value R H and the initial pulse energy value E 1 from the print head memory device 32 (step 112 ). In the preferred embodiment, the controller 22 then calculates an initial or first pulse width value T 1 according to: T 1 = E 1 I i 2 × R H     ( step     114 ) . ( 4 ) The controller 22 then sets the pulse width of the ink-firing pulses on the line 26 according to the value T 1 (step 116 ). The pulse width T 1 is preferably maintained in generating ink-firing pulses (step 118 ) for all subsequent printing operations which take place prior to the next occurrence of any one of the conditions of step 102 . If the controller 22 determines at step 110 that the pulse count value is greater than the threshold value, the controller 22 accesses the heating element resistance value R H and the adjusted pulse energy value E 2 from the print head memory device 32 (step 120 ). In the preferred embodiment, the controller 22 then calculates an adjusted or second pulse width value T 2 according to: T 2 = E 2 I i 2 × R H     ( step     122 ) . ( 5 ) The controller 22 then sets the pulse width of the ink-firing pulses on the line 26 according to the value T 2 (step 124 ). In this embodiment of the invention, the adjusted pulse width T 2 is preferably maintained in generating ink-firing pulses (step 118 ) for all subsequent printing operations during the lifetime of the print head 10 . As described above, the preferred embodiment of the invention stores several values in the memory 32 related to the initial measured resistances and rail voltage, the calculated initial current, the pulse count, the pulse count threshold value, and the initial and adjusted energy levels, and uses these stored values to calculate initial and adjusted pulse widths. In an alternative embodiment of the invention, only pulse width values are stored, such as an initial pulse width value to be used when the pulse count is less than a threshold value, and an adjusted pulse width value to be used when the pulse count is greater than a threshold value. For example, the initial pulse width value T 1 may be determined during the manufacture of the print head according to: T 1 = E 1 × ( R S + R H ) 2 V 2 × R H , ( 6 ) where V, R s , and R H are measured values as described above, and E 1 is the desired pulse energy to be maintained throughout the lifetime of the print head 10 . Similarly, the adjusted pulse width T 2 is determined and stored during the manufacture of the print head according to: T 2 = E 1 × ( R S + R 2 ) 2 V 2 × R 2 , ( 7 ) where R 2 is the predicted heating element resistance value after the pulse count exceeds the threshold value. In one embodiment of the invention, multiple pulse width adjustments are made during the lifetime of the print head 10 to compensate for changes in the heating element resistance R H . In this embodiment, N number of count threshold values are stored in memory, either in the print head memory 32 or in memory associated with the printer controller 22 . As described in more detail below, the pulse width of the ink firing pulses is adjusted in a number of steps as the pulse count exceeds a corresponding number of count threshold values. As with the previously-described embodiments, the process of this embodiment is preferably begun during the manufacture of the ink jet print head 10 by recording in the memory device 32 values related to print head characteristics that are used in determining an optimum pulse width for the ink-firing pulses (step 200 ). These values preferably include the rail voltage V, the initial heater resistance R H(1) , the series resistance R s , and the desired pulse energy value E 1 . The printer controller 22 accesses these stored values (step 202 ) and calculates an initial pulse width T N (for adjustment step N=1) based on the following expression: T N = E 1 × ( R S + R H  ( N ) ) 2 V 2 × R H  ( N )     ( step     204 ) . ( 8 ) The controller 22 accesses the pulse count value from the print head memory device 32 or from memory associated with the controller 22 , and determines based thereon how many ink-firing pulses have been generated by the print head 10 up to that point in the print head lifetime (step 206 ). The controller 22 accesses the pulse count threshold, also referred to as THRSHLD N , (where N =1) and determines whether the count value exceeds THRSHLD N . If not, the initial pulse width is maintained in generating the ink-firing pulses (step 210 ). If the pulse count exceeds THRSHLD N , then N is incremented by one (step 212 ), and a new heating element resistance value R H(N) is calculated. Preferably, the new resistance value is calculated (step 214 ) according to: R H(N) =R H(1) −ΔR H ,  (9) where ΔR H is a resistance change value calculated according to: ΔR H =R H(1) ×[A+B ×log( PC )].  (10) In equation (10), A and B are experimentally-determined constants, and PC is the current pulse count. Based on the new resistance value R H(N) , the controller 22 calculates an adjusted pulse width value T N* according to: T N * = T N - 1 2 + E 1 × ( R S + R H  ( N ) ) 2 2 × V 2 × R H  ( N )     ( step     216 ) , ( 11 ) and sets the pulse width accordingly (step 218 ). The newly-adjusted pulse width value T N* is used in generating the ink-firing pulses while the pulse count value is between the pulse count thresholds THRSHLD N and THRSHLD N−1 . For this embodiment, the number of adjustment steps and the pulse count threshold values THRSHLD N are determined based on characteristics of the particular print head 10 to provide the optimum print quality over the lifetime of the print head 10 . It is contemplated, and will be apparent to those skilled in the art from the preceding description and the accompanying drawings that modifications and/or changes may be made in the embodiments of the invention. Accordingly, it is expressly intended that the foregoing description and the accompanying drawings are illustrative of preferred embodiments only, not limiting thereto, and that the true spirit and scope of the present invention be determined by reference to the appended claims.

A thermal ink jet printing apparatus maintains stable printing output as certain characteristics of the apparatus change over its operational lifetime. The apparatus includes an ink jet print head with resistive heating elements for receiving electrical energy pulses having a voltage level and for transferring heat energy pulses having a desired energy level into adjacent ink based on the electrical energy pulses. The print head includes nozzles associated with the resistive heating elements through which droplets of the ink are ejected when the heat energy pulses are transferred into the ink. The apparatus further includes a printer controller in electrical communication with the print head. The printer controller determines a pulse count indicative of a number of electrical energy pulses, applies the electrical energy pulses having a first pulse width to the resistive heating elements when the pulse count is less than a threshold value, and applies the electrical energy pulses having an adjusted pulse width to the resistive heating elements when the pulse count exceeds the threshold value. The difference in the first and the adjusted pulse widths compensates for changes in the electrical resistance of the resistive heating elements over time.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of enumerating Universal Serial Bus (USB) devices. Specifically, embodiments of the present invention relate to a method and apparatus for providing a necessary amount of current for enumerating a USB device. 2. Related Art Devices that connect to a host computer by means of a USB bus may be referred to as USB devices. A USB device may be a printer, a scanner, a hard disk, a digital camera, a CD burner, etc., or any device configured to connect to a host system or device via a USB bus. Enumeration is the bus related process by which a USB device is attached to a system and is assigned a specific numerical address that will be used to access that particular device. It is also the time at which the USB host controller queries the device in order to decide what type of device it is in order to attempt to assign to it an appropriate driver. This process is a fundamental step for every USB device because, without it, the device would never be able to be used by the operating system. Until recently there were two classifications of USB devices, low speed devices and full speed devices. During the initial enumeration process, during which it identifies itself to the host and obtains an address, the device draws current from the V-bus line of the USB bus. A USB specification states that this current should not exceed 100 mA during enumeration. The low speed and full speed devices have had no trouble meeting the 100 mA specification. Once the initialization of the enumeration process is complete, the USB device may request to draw up to 500 mA, and may do so once the host has granted permission. Recent USB devices have been manufactured that operate at higher speeds (High-Speed USB) than the full speed devices and, as a result, they may draw current in excess of 100 mA during the initial process of enumeration. Manufacturers of high speed USB devices are finding it difficult to manufacture such a device that runs at less than 100 mA during the initial enumeration process. The consequence is that many manufacturers are having problems getting USB certification for their products or are producing products that are draining excess battery power from laptop computers or other wireless host devices in violation of the USB specification 2.0. SUMMARY OF THE INVENTION Accordingly, it would be desirable to have a method or device for enumerating a high speed USB device while meeting the USB specification for drawing no more than 100 mA from the USB bus during the initial enumeration process. According to embodiments of the present invention, USB enumeration architecture is provided herein that is compatible with the power specifications for a USB while able to enumerate high speed USB devices needing power in excess of the USB specifications. In various embodiments, a Universal Serial Bus (USB) device enumeration architecture is described herein comprising a USB bus for supplying a current during the USB device enumeration, a current mixer coupled to the bus, and a chargeable power source coupled to the USB bus. The USB bus is configured to charge the chargeable power source during a first time interval. Then, the chargeable power source is configured to discharge a current during a second time interval, the discharged current being mixed with the current from the USB bus for enumerating a USB device. In this fashion, the present invention allows the USB device to consume more power than the USB specification calls for during enumeration with the excess coming from the chargeable source. In this embodiment, the second time interval corresponds to the enumeration phase. In one embodiment, a USB device architecture is described that further comprises a current regulator coupled to the USB bus for regulating current supplied to the USB device from a host device. A state machine implemented control circuit may also be used. A USB device architecture is described, according to one embodiment, including control logic for switching from charging to discharging the chargeable power source following the first time interval. In one embodiment, a USB device architecture is described wherein the control logic comprises a timer for determining the first time interval. A USB device architecture is described, in accordance with one embodiment, further comprising a resistor for connecting the chargeable power source to the current mixer and the architecture to the USB device. In one embodiment a method for enumerating a USB device is also described wherein a chargeable power source is provided and coupled to a USB bus. The power source is charged during a first time interval with current from the USB bus and the power source is discharged during a second time interval. The resultant discharge current augments the current from the USB bus, thus providing sufficient current for enumerating a high speed USB device. The present embodiments provide the above advantages and others not specifically mentioned above but described in the sections to follow. Other features and advantages of the embodiments will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention: FIG. 1A is a block diagram of an overview of a timeline for the steps in enumerating a USB device in accordance with one embodiment of the present invention. FIG. 1B is a block diagram of the specified current limits for a USB bus integrated with the block diagram of FIG. 1A , according to an embodiment of the present invention. FIG. 1C is a block diagram of a method of supplementing USB current integrated with the block diagram of FIGS. 1A and 1B , according to an embodiment of the present invention. FIG. 2 is a block diagram of USB device enumeration architecture, according to one embodiment of the present invention. FIG. 3 is flow diagram of a method for augmenting current for enumerating a high speed USB device in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS In the following detailed description of the embodiments, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without some specific details or with equivalents thereof. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments. In accordance with the embodiments, a USB device enumeration architecture is designed using a chargeable power source for augmenting USB bus current for enumerating a USB device. The USB device enumeration architecture includes a chargeable power source that may be charged from the USB bus current during a first time interval and, subsequently, discharged to augment the USB bus current during a second time interval while the USB device is being enumerated. This allows high speed USB devices to be enumerated without exceeding the design specifications for USB busses that specify the current draw from the USB bus during enumeration remain at or below a low limit (e.g., 100 mA). FIG. 1A is a flow diagram 100 a of an overview of a timeline for the steps in enumerating a USB device according to one aspect of the embodiments. In block 110 , a USB device is plugged into a USB port, e.g., of a hub or host computing device, like a laptop computer. The USB device may be a low speed, full speed or high speed device. It may be any of a variety of devices configured to attach to a host computing device (e.g., a computer) by means of a USB port. Block 115 of diagram 100 a represents a first time interval, t 1 , during which a chargeable power source, such as a capacitor or a battery, is charging from current supplied by a v-bus within the USB bus in accordance with an aspect of the embodiments. Time, t 1 , may vary depending on design parameters, but might be expected to be of a duration of approximately 100 milliseconds (ms). During time t 1 , the USB device is not logically attached to the USB bus. According to one embodiment, the charge built up at the chargeable power source may be determined at the end of a predetermined time period (e.g., 100 ms) and if not sufficient for the device to be enumerated, an extension period to time t 1 (e.g., 100 ms) may be granted. This may be repeated. The chargeable power source may then continue to charge until a sufficient charge is accumulated for enumerating the device. Still referring to FIG. 1A , block 120 illustrates the USB device logically attaching to the USB bus according to one embodiment. At this point, the chargeable power source is sufficiently charged and the enumeration architecture is set to discharge the power source. At block 120 the USB device pulls up a D+ data line from the USB bus, initializing the enumeration process. Block 125 of FIG. 1A represents a second time interval, t 2 , according to one embodiment. During time interval, t 2 , the initial phase of the enumeration process occurs, and the chargeable power source is being discharged to supplement the specified low current limit from the USB bus when needed. Therefore, during t 2 , the USB device consumes only the specified amount (e.g., 100 mA) from the USB bus with any extra coming from the chargeable power source. Once the host device has sufficient information from the enumeration to recognize the USB device and its current and bandwidth requirements, etc., the host may issue a command that grants the USB device up to a specified high current limit (e.g., 500 mA) from the USB bus. At this point, the chargeable power source is no longer needed and the USB device may finish any portion of enumeration not completed and operate with the 500 mA for an indeterminate time period as illustrated by period t 3 of block 135 . It should be understood that the values of 100 mA and 500 mA are representative of limits in USB specifications at the time of the present application and may be any limit values within reasonable range of 100 mA and 500 mA as might be specified in any USB specification. FIG. 1B is a block diagram 100 b of the specified current limits for a USB bus integrated with the block diagram of FIG. 1A , according to an embodiment of the present invention. Block 140 represents the duration of the specified 100 mA current from the USB bus. According to one embodiment, the 100 mA current limit (from the USB bus) is in force throughout time intervals t 1 and t 2 of FIG. 1A . That is, the 100 mA is in force until the host device grants permission for the USB device to use up to 500 mA of current as illustrated, according to one aspect of the embodiments, by block 150 of FIG. 1B . FIG. 1C is a charging diagram 100 c for supplementing USB current integrated with the diagrams of FIGS. 1A and 1B , according to an embodiment of the present invention. Block 160 illustrates the charging of a chargeable power source (e.g., a battery or capacitor) during time interval t 1 . It should be appreciated that if insufficient charge is accumulated over a first interval t 1 , that t 1 may repeat over and over until such time as sufficient charge has accumulated at the chargeable power source. Still referring to FIG. 1C , block 170 illustrates the discharging of power from the chargeable power source to supplement the 100 mA USB current for enumeration during time interval t 2 , according to one embodiment. At the beginning of interval t 2 , control logic (e.g., control logic 225 of FIG. 2 ) activates a pull-up resistor (e.g. 230 of FIG. 2 ) and switches (e.g., switches 240 and 235 of FIG. 2 ) are set to discharge (discharge=1) the power source for supplementing the 100 mA current. Thus, the USB device may be enumerated within the USB specifications. FIG. 2 is a block diagram of USB device enumeration architecture 200 in accordance with an embodiment of the present invention. USB bus 210 is also shown. Device 200 includes current regulator 215 , chargeable power source 220 , control logic and attach timer 225 and attach pull-up resistor 230 , according to one embodiment of the present invention. Also included in architecture 200 , according to an embodiment of the present invention, are switches 235 and 240 (controlled by circuit 225 ), current mixer 245 and USB device 250 . Architecture 200 may, in one embodiment, reside within USB device 250 or, according to another embodiment, architecture 200 may be made available as a separate power monitor or power maintenance chip coupled to the USB bus 210 . Still referring to FIG. 2 , USB bus 210 may be a standard USB (Universal Serial Bus) bus that is well known to those skilled in the art. USB bus 210 is designed to connect a variety of peripheral devices to a host device. Bus 210 has four lines, a voltage v-bus line, two data lines (D+ and D−) and a ground line. The specification for USB bus 210 limits the current draw of a USB device (e.g., USB device 250 ) to a low limit (e.g., 100 mA) until such time as a host device (to which the USB device is attaching via USB bus 210 ) grants permission to increase the current draw to a maximum limit (e.g., 500 mA). USB device 250 will identify itself to the host device to receive an address, a driver and configuration with the host. This process of a device identifying itself to the host and becoming configured for the host is known as enumeration. High speed USB devices frequently need in excess of the specified low limit in order to be enumerated. Current regulator 215 of FIG. 2 is a circuit designed to regulate the current from the v-bus line of USB 210 so as not to exceed the low limit (e.g., 100 mA) during the enumeration of device 250 until such time as a host (not shown) grants permission to increase the current to a high limit (e.g., 500 mA). Current regulator 215 then regulates the current to remain at or below the specified high limit. Regulator 215 receives a control signal 217 and during enumeration this signal limits regulator 215 to supply only 100 mA and, otherwise, it may supply 500 mA. Still referring to FIG. 2 , during the first time interval (t 1 of FIG. 1A ) when the USB device has first been plugged into the USB bus 210 , control logic circuit 225 causes switch 240 to be set to discharge=0, attaching chargeable power source 220 to current regulator 215 and v-bus of USB 210 . Signal 217 is low and 100 mA is regulated. Switch 235 remains open and the data lines of USB bus 210 are not pulled up so that USB device 250 is not attached to the circuit or the host during time interval t 1 . Control logic circuit 225 generates the charge/discharge signal 219 controlling the switched chargeable power source. During this time, as measured by circuit 225 , chargeable power source 220 is drawing current from USB 210 , as regulated by current regulator 215 . Only 100 mA maximum may be drawn at this phase. Control logic and attach timer 225 of FIG. 2 determine the end of time intervals t 1 and t 2 , according to one embodiment. When t 1 has ended, control logic and attach timer 225 sends a signal to attach pull-up resistor 230 that pulls up data line D-plus and causes switch 240 to change to the discharge=1 position. Switch 235 closes, thus, along with the D-plus line, attaching USB device 250 to the USB bus and to the host device. Signal 217 is still low. At this time, chargeable power source 220 is available to discharge current into current mixer 245 where the USB bus current can be supplemented and mixed with the discharged current from chargeable power source 220 for enumerating USB device 250 . In summary, during time interval t 2 enumeration is occurring and the USB device may draw more power than 100 mA with the excess deriving from the chargeable power supply 220 and the 100 mA deriving from the USB bus 210 . At the end of time interval t 2 , when the host device has granted permission to USB device 250 to come aboard, control logic and attach timer 225 signals current regulator 215 to allow the v-bus of USB bus 210 to output up to the maximum high limit (e.g., 500 mA) current. At this time, in accordance with one embodiment, the USB device enumeration architecture has completed its task. At this time, signal 217 goes high, allowing 500 mA to be regulated by regulator 215 . The current regulator 215 , current mixer 245 , switches 235 and 240 , chargeable power source 220 and control logic and attach timer 225 can be integrated within USB device 250 or they may be integrated within a separate power maintenance device or chip for connecting to the USB device. Control logic 225 may be implemented by a state machine. FIG. 3 is flow diagram 300 of a process for augmenting current for enumerating a high speed USB device in accordance with one embodiment of the present invention. Although specific steps are disclosed in flow diagram 300 , such steps are exemplary. That is, the present invention is well suited to performing various other steps or variations of the steps recited in FIG. 3 . At step 310 of FIG. 3 . A USB device (e.g., USB device 250 of FIG. 2 ) is plugged into a USB bus (e.g., USB bus 210 of FIG. 2 ). During a first time interval t 1 after the USB device has been plugged into the USB bus, USB device 250 is not attached to the circuit or the host. At step 320 of FIG. 3 , a chargeable power source (e.g., chargeable power source 220 of FIG. 2 ) is drawing current from USB bus 210 , over a time interval t 1 . At the end of time interval t 1 , step 330 is entered and USB device 250 is attached to the host device through USB bus 210 and enumeration architecture 200 and enumeration is begun in accordance with one aspect of the embodiments, provided there is sufficient current available. If there is insufficient current at any point during step 330 , step 340 of process is entered and the process returns to step 320 for further charging of the chargeable power source. This step may be repeated as often as necessary until step 350 may be entered. At step 350 , according to one embodiment, the host device has completed the initial enumeration process and allocates the USB device permission for the higher USB current limit so that it may be fully attached. At this point the chargeable power source and the USB enumeration architecture are no longer needed and the process exits flow diagram 300 . The foregoing descriptions of specific embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

A method and device for supplementing current from the USB bus for enumerating USB devices that require additional current beyond that allowable by USB bus specification. A chargeable power source, such as a capacitor or rechargeable battery, is supplied to the enumeration circuitry and is charged from the USB bus for an initial period of time. The charged power source is then discharged to supplement the allowable current available for enumeration during a second period of time. It is during this second period of time that the enumeration takes place. The circuitry may exist in the USB device or may be supplied separately as a power monitor or power maintenance chip or device.

This Non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 2003-121366 filed in Japan on Apr. 25, 2003, the entire contents of which are hereby incorporated by reference. FIELD OF THE INVENTION This invention relates to processes for preparing silyl ketene acetals and disilyl ketene acetals which are useful as initiators for group transfer polymerization and intermediates for the synthesis of pharmaceutical, agricultural and various other organic compounds. BACKGROUND ART For silyl ketene acetals, Petrov et al. first reported their synthesis (see J. Gen. Chem. (USSR), 1959, vol. 29, pp. 2896-2899). The silyl ketene acetals are compounds of great commercial interest. One of their applications is the use as polymerization initiators in the polymerization of acrylate monomers, known as “group transfer polymerization,” developed by Webster et al. (see U.S. Pat. No. 4,417,034 and U.S. Pat. No. 4,508,880). Another application is the use as nucleophilic agents in the synthesis of carboxylic acid derivatives (see JP-A 2001-247514). Disilyl ketene acetals are regarded as one class of silyl ketene acetals from the standpoint of chemical structure. Therefore, most of their preparation processes are in accord with processes of silyl ketene acetal preparation. Heretofore, for the preparation of silyl ketene acetals, four predominant processes are known in the art. They are (1) the reaction of a carboxylic ester having a hydrogen atom at α-position with a base and a silylating agent; (2) the activation of a carboxylic ester having a halogen atom substituted at α-position with a metal such as sodium or zinc, followed by reaction with a silylating agent such as chlorotrimethylsilane; (3) the reaction of a malonic ester with a silylating agent such as chlorotrimethylsilane in the presence of metallic sodium; and (4) the reaction of an α,β-unsaturated carboxylic ester with a hydrosilane or hydrosiloxane in the presence of a transition metal catalyst. In process (1), typical combinations of base/silylating agent include lithium diisopropylamide/chlorotrimethylsilane (see JP-A 9-221444, for example) and triethylamine/trimethylsilyl trifluoromethanesulfonate (see U.S. Pat. No. 4,482,729, for example). In either case, reaction proceeds at room temperature or lower temperatures, but requires to use at least one equivalent of the base, forming a large amount of salt. This is detrimental particularly when the process is applied to a large scale of production. The latter combination sometimes results in low yields with certain substrates because a compound having alpha-carbon silylated is produced in addition to the desired silyl ketene acetal. In process (2) as exemplified by JP-A 2-111780 and process (3) as exemplified by JP-A 64-85982, at least one equivalent of a metal such as sodium is used, forming a large amount of metal salt. The metal salt must be removed before the desired silyl ketene acetal can be isolated. Also, since the metal is often used in excess, the metal salt formed contains metal in the activated state, requiring careful handling. Thus these processes are difficult to implement on a large scale. Unlike processes (1) to (3), process (4) utilizes addition reaction, offering the advantage that no waste products like the above-mentioned salt are formed. It is known that this process uses transition metal compounds as the catalyst. In the article of Petrov et al., for example, a platinum compound is used as the catalyst. Among others, rhodium catalysts are effective. For instance, chlorotris(triphenylphosphine)rhodium is used in Chem. Pharm. Bull., 1974, vol. 22, pp. 2767-2769 and JP-A 63-290887 and rhodium trichloride trihydrate used in JP-A 62-87594. In U.S. Pat. No. 5,208,358 a successful use of chlorobis(di-tert-butylsulfide)rhodium as a catalyst has been disclosed in producing silyl ketene acetals with lower catalyst loadings. However, as described in JP-A 62-87594, when hydrosilylation reaction is catalyzed by transition metal catalysts, there are formed not only the desired silyl ketene acetal, but also by-products such as carbonyl adducts or β-adducts which have a boiling point close to the desired product and are difficult to separate by distillation. It is then difficult to obtain silyl ketene acetals with high purity. In JP-A 62-87594, a silyl ketene acetal is obtained in a highly pure form (≧95%) by using rhodium trichloride trihydrate as the catalyst and an excess amount of hydrosilane and converting the carbonyl adduct to a high-boiling compound. However, by this process, it was difficult to obtain silyl ketene acetals in high yields because of the decreased yields based on the hydrosilane used, and of the increased distillation residue leading to lower isolated yields. Thus, the process of making silyl ketene acetals by hydrosilylation of α,β-unsaturated carboxylic esters is advantageous in that it does not essentially generate by-products such as salts. Nonetheless, with conventional transition metal catalysts, it suffers from the low selectivity owing to the formation of multiple products derived from a variety of hydrosilylation modes. It would be desirable to have a process of preparing a silyl ketene acetal at a good selectivity, high purity and high yield. For the preparation of disilyl ketene acetals, any of the foregoing processes is applicable. The preparation of disilyl ketene acetals generally starts with silyl carboxylic esters, most of which are not commercially available. This necessitates the extra step of preparing silyl carboxylates beforehand through silylation of carboxylic acids, adding to the cost of manufacture. A process other than stated above has been proposed for disilyl ketene acetal manufacturing: a reaction between α,β-unsaturated carboxylic esters and hydrosilanes in the presence of a rhodium catalyst (see JP-A 64-71886). With this process, disilyl ketene acetals can be obtained in one step using allyl esters of α,β-unsaturated carboxylic acids such as commercially available allyl methacrylate. Although the reaction mixture resulting from this process is allegedly free of a typical by-product, carbonyl adduct, the yield and purity of the desired product are below satisfactory levels because other by-products are formed in noticeable amounts. The existing processes for the preparation of disilyl ketene acetals suffer from drawbacks such as large amounts of by-product generation and laborious purification of the desired compounds. It would be desirable to have a process of preparing disilyl ketene acetals in high purity and high yields without forming substantial by-products. SUMMARY OF THE INVENTION An object of the invention is to provide processes of preparing silyl ketene acetals and disilyl ketene acetals in high purity and high yields without forming substantial by-products such as salts. The inventors have found that by reacting an α,β-unsaturated carboxylic ester with a hydrosilane or hydrosiloxane in the presence of a catalytic amount of tris(pentafluorophenyl)borane, a silyl ketene acetal or disilyl ketene acetal with high purity is produced in high yields depending on the ratio of the α,β-unsaturated carboxylic ester and the hydrosilane or hydrosiloxane. A first embodiment of the invention is a process for preparing a silyl ketene acetal of the general formula (3), comprising the step of reacting an α,β-unsaturated carboxylic ester of the general formula (1) with a hydrosilane or hydrosiloxane of the general formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. Herein R 1 , R 2 and R 3 are each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, or a pair of R 1 and R 2 or R 1 and R 3 may bond together to form a ring of 3 to 20 carbon atoms with the carbon atom(s) to which they are attached, and R 4 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms or a substituted or unsubstituted silyl group of up to 60 carbon atoms and free of a SiH bond. Herein R a , R b and R c are independently selected from a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, an organoxy group of 1 to 20 carbon atoms, an organo(poly)siloxy group of 1 to 1,000 silicon atoms, and a halogen atom, or a pair of R a and R b , R a and R c , or R b and R c may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are attached, or R a , R b and R c may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are attached. Herein R 1 , R 2 , R 3 , R 4 , R a , R b and R c are as defined in formulae (1) and (2). In one preferred embodiment, a reactor is charged with a mixture of the hydrosilane or hydrosiloxane of formula (2) and a catalytic amount of tris(pentafluorophenyl)borane, and the α,β-unsaturated carboxylic ester of formula (1) is then added to the reactor. In another preferred embodiment, a reactor is charged with a catalytic amount of tris(pentafluorophenyl)borane, and the α,β-unsaturated carboxylic ester of formula (1) and the hydrosilane or hydrosiloxane of formula (2) are then added to the reactor in controlled amounts so as to provide 0.9 to 1.1 moles of Si—H bonds on the compound of formula (2) per mole of the compound of formula (1). A second embodiment of the invention is a process for preparing a disilyl ketene acetal of the general formula (5), comprising the step of reacting an α,β-unsaturated carboxylic ester of the general formula (4) with a hydrosilane or hydrosiloxane of the general formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. Herein R 5 , R 6 and R 7 are each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, or a pair of R 5 and R 6 or R 5 and R 7 may bond together to form a ring of 3 to 20 carbon atoms with the carbon atom(s) to which they are attached, and R 8 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms. Herein R a , R b and R c are as defined above. Herein R 5 , R 6 , R 7 , R a , R b and R c are as defined in formulae (4) and (2). In a preferred embodiment, a reactor is charged with a mixture of the hydrosilane or hydrosiloxane of formula (2) and a catalytic amount of tris(pentafluorophenyl)borane, and the α,β-unsaturated carboxylic ester of formula (4) is then added to the reactor in an amount of up to 0.5 mole per mole of Si—H bonds on the compound of formula (2). A third embodiment of the invention is a process for preparing a disilyl ketene acetal of the general formula (7), comprising the step of reacting a silyl ketene acetal of the general formula (6) with a hydrosilane or hydrosiloxane of the general formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. Herein R 9 and R 10 are each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, or a pair of R 9 and R 10 may bond together to form a ring of 3 to 20 carbon atoms with the carbon atom to which they are attached, R 11 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms, R d , R e and R f are independently selected from a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, an organoxy group of 1 to 20 carbon atoms, an organo(poly)siloxy group of 1 to 1,000 silicon atoms, and a halogen atom, or a pair of R d and R e , R d and R f , or R e and R f may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are attached, or R d , R e and R f may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are attached. Herein R a , R b and R c are as defined above. Herein R 9 , R 10 , R a , R b , R c , R d , R e and R f are as defined in formulae (6) and (2). With the processes of the present invention, silyl ketene acetals and disilyl ketene acetals with high purity can be produced in high yields without forming substantial by-products such as salts. The silyl ketene acetals obtained by the process of the first embodiment are quite useful in polymer synthesis and organic synthesis. Using raw materials which are available on a commercial scale, the process of the second embodiment is able to produce in one stage disilyl ketene acetals which are commercially quite useful in polymer synthesis and organic synthesis. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment of the invention, silyl ketene acetals are prepared using α,β-unsaturated carboxylic acid esters of the general formula (1) as the starting material. In formula (1), each of R 1 , R 2 and R 3 is independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, preferably 1 to 20 carbon atoms. Preferred unsubstituted monovalent hydrocarbon groups are those of 1 to 20 carbon atoms. The substituted monovalent hydrocarbon groups correspond to the unsubstituted monovalent hydrocarbon groups in which some or all of the hydrogen atoms bonded to carbon atoms are substituted with substituent groups. Suitable substituent groups include halogen atoms, alkoxy groups of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, organoxy groups such as alkenyloxy and aryloxy groups, silyl groups of up to 60 carbon atoms and free of a SiH bond, and organo(poly)siloxy groups of 1 to 1,000 silicon atoms, preferably 1 to 50 silicon atoms, most preferably 1 to 10 silicon atoms. Examples of the groups represented by R 1 , R 2 and R 3 include straight, branched or cyclic, substituted or unsubstituted alkyl groups such as methyl, chloromethyl, bromobutyl, iodomethyl, trifluoromethyl, trimethylsilylmethyl, tris(trimethylsiloxy)silylmethyl, tris(trimethylsiloxy)siloxymethyl, ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-trimethylsiloxyethyl, 2-triethylsiloxyethyl, n-propyl, 3-(trimethoxysilyl)propyl, 3-(triethoxysilyl)propyl, 3-tris(trimethylsiloxy)silylpropyl, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl, (3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)methyl, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl, 3-(pentamethyldisiloxanyloxy)propyl, 3-(ω-butylpolydimethylsiloxan-1-yloxy)propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, decyl, dodecyl, and stearyl; straight, branched or cyclic, substituted or unsubstituted alkenyl groups such as vinyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, decenyl and undecenyl; straight, branched or cyclic, substituted or unsubstituted alkynyl groups such as ethynyl, propynyl and butynyl; substituted or unsubstituted aryl groups such as phenyl, 4-fluorophenyl, 4-tert-butylphenyl, pentafluorophenyl, 2-tolyl, 3-tolyl, 4-tolyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, 3,5-dimethylphenyl, 3,4-dimethylphenyl, 2,5-dimethylphenyl, naphthyl and biphenylyl; and substituted or unsubstituted aralkyl groups such as benzyl, 2-chlorobenzyl, 4-bromobenzyl, 4-methoxybenzyl, phenylethyl and phenylpropyl. In formula (1), a pair of R 1 and R 2 or a pair of R 1 and R 3 may bond together to form a ring of 3 to 20 carbon atoms, especially 5 to 12 carbon atoms, with the carbon atom or atoms to which they are attached. Suitable rings include cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclooctadiene, norbornene and indene rings. In formula (1), R 4 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms, preferably 1 to 20 carbon atoms, or a substituted or unsubstituted silyl group of up to 60 carbon atoms and free of a SiH bond. Preferred unsubstituted monovalent hydrocarbon groups are those of 1 to 20 carbon atoms. Preferred unsubstituted, SiH bond-free silyl groups are those of up to 40 carbon atoms. The substituted monovalent hydrocarbon and substituted organosilyl groups correspond to the unsubstituted monovalent hydrocarbon and unsubstituted organosilyl groups, respectively, in which some or all of the hydrogen atoms bonded to carbon atoms are substituted with substituent groups. Suitable substituent groups include halogen atoms, alkoxy groups of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, organoxy groups such as alkenyloxy and aryloxy groups, silyl groups of up to 60 carbon atoms and free of a SiH bond, and organo(poly)siloxy groups of 1 to 1,000 silicon atoms, preferably 1 to 200 silicon atoms. Examples of R 4 include the groups exemplified above for R 1 , R 2 and R 3 as well as organosilyl groups such as trimethylsilyl, chloromethyldimethylsilyl, (trimethylsilylmethyl)dimethylsilyl, ethyldimethylsilyl, 3-chloropropyldimethylsilyl, 3,3,3-trifluoropropyldimethylsilyl, diethylmethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, triisobutylsilyl, tert-butyldimethylsilyl, cyclopentyldimethylsilyl, hexyldimethylsilyl, cyclohexyldimethylsilyl, thexyldimethylsilyl, thexyldiisopropylsilyl, decyldimethylsilyl, octadecyldimethylsilyl, benzyldimethylsilyl, dimethylphenylsilyl, methyldiphenylsilyl, triphenylsilyl, tri-p-tolylsilyl, tri-o-tolylsilyl, methoxydimethylsilyl, dimethoxymethylsilyl, trimethoxysilyl, ethyldimethoxysilyl, propyldimethoxysilyl, ethoxydimethylsilyl, diethoxymethylsilyl, triethoxysilyl, isopropoxydimethylsilyl, sec-butoxydimethylsilyl, tert-butoxydimethylsilyl, dimethylphenoxysilyl, benzyloxydimethylsilyl, chlorodimethylsilyl, dichloromethylsilyl, trichlorosilyl, chlorodiethylsilyl, dichloroethylsilyl, chlorodiphenylsilyl, dichlorophenylsilyl, pentamethyldisiloxanyl, 3-chloropropyl-1,1,3,3-tetramethyldisiloxanyl, 1,1,3,3,5,5,5-heptamethyltrisiloxanyl, 1,1,1,3,5,5,5-heptamethyltrisiloxanyl, 1,3,3,5,5,7,7-heptamethylcyclotetrasiloxan-1-yl, tris(trimethylsiloxy)silyl, 3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl, 3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl, and ω-butylpolydimethylsiloxan-1-yl. Illustrative, non-limiting, examples of the α,β-unsaturated carboxylic esters of formula (1) include methyl acrylate, ethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, 1,1,2-trimethylpropyl acrylate, vinyl acrylate, allyl acrylate, isopropenyl acrylate, 1-cyclohexenyl acrylate, 10-undecenyl acrylate, ethynyl acrylate, trimethylsilyl acrylate, triethylsilyl acrylate, triisopropylsilyl acrylate, tert-butyldimethylsilyl acrylate, methyl methacrylate, ethyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-trimethylsiloxyethyl methacrylate, 2-chloropropyl methacrylate, 3-triethylsilylpropyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-(triethoxysilyl)propyl methacrylate, 3-tris(trimethylsiloxy)silylpropyl methacrylate, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl methacrylate, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl methacrylate, (3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)methyl methacrylate, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)propyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 1,1,2-trimethylpropyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, isobornyl methacrylate, octadecyl methacrylate, vinyl methacrylate, allyl methacrylate, isopropenyl methacrylate, 1-cyclohexenyl methacrylate, 10-undecenyl methacrylate, ethynyl methacrylate, benzyl methacrylate, phenyl methacrylate, trimethylsilyl methacrylate, (3-chloropropyldimethylsilyl)methacrylate, (dimethyl-3,3,3-trifluoropropylsilyl)methacrylate, triethylsilyl methacrylate, triisopropylsilyl methacrylate, tert-butyldimethylsilyl methacrylate, (1,1,3,3,3-pentamethyldisiloxan-1-yl)methacrylate, (1,3,3,5,5,7,7-heptamethylcyclotetrasiloxan-1-yl)methacrylate, (3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)methacrylate, (3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)methacrylate, (3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)methacrylate, methyl crotonate, methyl cinnamate, ethyl 4-chlorocinnamate, methyl 4-methoxycinnamate, methyl 1-cyclohexenecarboxylate, methyl cyclohexylideneacetate, 1,1,3,3,3-pentamethyl-1-[3-(methacryloyloxy)propyl]-disiloxane, and α-[3-(methacryloyloxy)propyl]-ω-butyl-polydimethylsiloxane. In the process for preparing a silyl ketene acetal according to the first embodiment of the invention, the α,β-unsaturated carboxylic ester of formula (1) is reacted with a hydrosilane or hydrosiloxane of the following general formula (2). In formula (2), each of R a , R b and R c is independently selected from among a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an organoxy group of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an organo(poly)siloxy group of 1 to 1,000 silicon atoms, and a halogen atom. Examples of the groups represented by R a , R b and R c include straight, branched or cyclic, substituted or unsubstituted alkyl groups such as methyl, chloromethyl, trifluoromethyl, ethyl, propyl, 3-chloropropyl, 3,3,3-trifluoropropyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, decyl, dodecyl, and stearyl; substituted or unsubstituted aryl groups such as phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-iodophenyl, pentafluorophenyl, tolyl, xylyl, naphthyl and biphenylyl; substituted or unsubstituted aralkyl groups such as benzyl, phenylethyl and phenylpropyl; substituted or unsubstituted alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, isobutoxy, cyclopentyloxy, cyclohexyloxy, and norbornyloxy; substituted or unsubstituted aryloxy groups such as phenoxy, 3-chlorophenoxy and naphthyloxy; substituted or unsubstituted aralkyloxy groups such as benzyloxy, 2-chlorobenzyloxy, 3-chlorobenzyloxy, 4-chlorobenzyloxy and naphthylethyloxy; and straight, branched or cyclic, substituted or unsubstituted organo(poly)siloxy groups such as dimethylsiloxy, diethylsiloxy, diphenylsiloxy, trimethylsiloxy, chloromethyldimethylsiloxy, triethylsiloxy, phenyldimethylsiloxy, diphenylmethylsiloxy, 1,1,3,3,3-pentamethyldisiloxanyloxy, 1,1,3,3-tetramethyldisiloxanyloxy, bis(trimethylsiloxy)siloxy, methylbis(trimethylsiloxy)siloxy, tris(trimethylsiloxy)siloxy, 1,3,3,5,5-pentamethylcyclotrisiloxan-1-yloxy, 1,3,5-trimethyl-3,5-bis(3,3,3-trifluoropropyl)cyclotrisiloxan-1-yloxy, 1,3,5,7-tetramethylcyclotetrasiloxan-1-yloxy, ω-methylpolydimethylsiloxanyloxy, ω-hydropolydimethylsiloxanyloxy, and polyhydromethylsiloxanyloxy. A pair of R a and R b , a pair of R a and R c , or a pair of R b and R c may bond together to form a siloxane ring of 3 to 50 silicon atoms, preferably 3 to 20 silicon atoms, or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are attached. Alternatively, R a , R b and R c may bond together to form a cage siloxane of 6 to 50 silicon atoms, preferably 6 to 20 silicon atoms with the silicon atom to which they are attached. Illustrative, non-limiting examples of cage siloxane rings are given below. Illustrative, non-limiting examples of the compounds of formula (2) include organohydrosilanes such as trimethylsilane, chloromethyldimethylsilane, (trimethylsilylmethyl)dimethylsilane, ethyldimethylsilane, 3-chloropropyldimethylsilane, 3,3,3-trifluoropropyldimethylsilane, diethylmethylsilane, triethylsilane, tripropylsilane, trusopropylsilane, tributylsilane, trisobutylsilane, tert-butyldimethylsilane, cyclopentyldimethylsilane, hexyldimethylsilane, cyclohexyldimethylsilane, thexyldimethylsilane, thexyldiisopoprylsilane, decyldimethylsilane, octadecyldimethylsilane, benzyldimethylsilane, dimethylphenylsilane, methyldiphenylsilane, triphenylsilane, tri-p-tolylsilane, tri-o-tolylsilane, 1,4-bis(dimethylsilyl)benzene, methoxydimethylsilane, dimethoxymethylsilane, trimethoxysilane, ethyldimethoxysilane, propyldimethoxysilane, ethoxydimethylsilane, diethoxymethylsilane, triethoxysilane, isopropoxydimethylsilane, sec-butoxydimethylsilane, tert-butoxydimethylsilane, dimethylphenoxysilane, benzyloxydimethylsilane, chlorodimethylsilane, dichloromethylsilane, trichlorosilane, chlorodiethylsilane, dichloroethylsilane, chlorodiphenylsilane, and dichlorophenylsilane; and straight, branched, cyclic or cage organohydrosiloxanes such as pentamethyldisiloxane, 3-chloropropyl-1,1,3,3-tetramethyldisiloxane, 1,1,3,3,5,5,5-heptamethyltrisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,1,3,3-tetraisopropyldisiloxane, 1,3-dimethyl-1,3-diphenyldisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,1,3,5,5,5-heptamethyltrisiloxane, 1,1,1,3,5,7,7,7-octamethyltetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris(trimethylsiloxy)silane, 1-hydrido-3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane, 1-(hydridodimethylsiloxy)-3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane, 1,3,5,7,9,11,13,15-octakis(dimethylsiloxy)pentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane, α-hydro-ω-methylpolydimethylsiloxane, α,ω-dihydropolydimethylsiloxane, and polymethylhydrosiloxane. Preferably the compound of formula (2) is used in such amounts as to provide 0.9 to 1.1 moles of Si—H bonds on the compound of formula (2) per mole of the compound of formula (1). If either one of the compounds of formulae (1) and (2) is used in large excess, the percent yield of the product based on that compound is reduced and side reactions may occur in a more proportion to further reduce the yield. In the preparation of silyl ketene acetals according to the first embodiment of the invention, the compound of formula (1) is reacted with the compound of formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. The amount of tris(pentafluorophenyl)borane used varies with the reaction substrates although it is usually 0.00001 to 10 mol %, preferably 0.0001 to 1 mol % based on the compound of formula (1). The reaction is generally effected under atmospheric pressure and in an inert gas atmosphere such as nitrogen although the process is not limited thereto. The reaction temperature is usually in the range of −100° C. to 100° C., preferably −20° C. to 60° C. For the preparation of a silyl ketene acetal, the compound of formula (1) wherein R 4 is bonded to the oxygen atom via primary or secondary sp 3 carbon is often used in the following embodiments. In one embodiment wherein the α,β-unsaturated carboxylic ester of formula (1) is added to a reactor charged with a mixture of the hydrosilane or hydrosiloxane of formula (2) and a catalytic amount of tris(pentafluorophenyl)borane, the reaction temperature is preferably set in the range of −100° C. to −20° C. In another embodiment wherein a reactor is charged with a catalytic amount of tris(pentafluorophenyl)borane, and the α,β-unsaturated carboxylic ester of formula (1) and the hydrosilane or hydrosiloxane of formula (2) are added to the reactor in controlled amounts so as to provide 0.9 to 1.1 moles of Si—H bonds on the compound of formula (2) per mole of the compound of formula (1), the reaction temperature is preferably set in the range of −50° C. to 30° C. Any desired mode may be used in the mixing of the substrates and the catalyst as long as attention is paid to the fact that the α,β-unsaturated carboxylic ester of formula (1) is generally polymerizable. To control reaction conditions to suppress the possibility of polymerization, it is recommended that the reaction be performed by feeding the compound of formula (1) to a reactor charged with the catalyst and the compound of formula (2) or by feeding both the compounds of formulae (1) and (2) to a reactor charged with the catalyst. In the latter case, the compounds are preferably fed in controlled rates so as to provide 0.9 to 1.1 moles of Si—H bonds on the compound of formula (2) per mole of the compound of formula (1). A reaction solvent is not always necessary. Especially when both the reaction substrates (1) and (2) are liquid, the reaction can proceed in a solventless system. Of course, a solvent may be used for the reaction to take place. Suitable solvents include hydrocarbon solvents such as hexane, isooctane, benzene, toluene, and xylene, and halogenated hydrocarbon solvents such as dichloromethane and dichloroethane. A polymerization inhibitor is optionally added during the reaction. Suitable polymerization inhibitors, if used, are hindered phenols such as 2,6-di-tert-butyl-4-methylphenol (BHT) and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene. By the process in the first embodiment of the invention described above, the silyl ketene acetals of the following general formula (3) are obtainable. In formula (3), R 1 , R 2 , R 3 , R 4 , R a , R b and R c are as defined above. In the second embodiment of the invention, disilyl ketene acetals are prepared using α,β-unsaturated carboxylic acid esters of the general formula (4) as the starting material. In formula (4), each of R 5 , R 6 and R 7 is independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, preferably 1 to 20 carbon atoms. Preferred unsubstituted monovalent hydrocarbon groups are those of 1 to 20 carbon atoms. The substituted monovalent hydrocarbon groups correspond to the unsubstituted monovalent hydrocarbon groups in which some or all of the hydrogen atoms bonded to carbon atoms are substituted with substituent groups. Suitable substituent groups include halogen atoms, alkoxy groups of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, organoxy groups such as alkenyloxy and aryloxy groups, silyl groups of up to 60 carbon atoms and free of a SiH bond, and organo(poly)siloxy groups of 1 to 1,000 silicon atoms, preferably 1 to 50 silicon atoms, most preferably 1 to 10 silicon atoms. Examples of the groups represented by R 5 , R 6 and R 7 are as exemplified for R 1 , R 2 and R 3 in formula (1). In formula (4), a pair of R 5 and R 6 or a pair of R 5 and R 7 may bond together to form a ring of 3 to 20 carbon atoms, especially 5 to 12 carbon atoms, with the carbon atom or atoms to which they are attached. Suitable rings include cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclooctadiene, norbornene and indene rings. In formula (4), R 8 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms. Examples of the groups represented by R 8 are as exemplified for R 1 , R 2 and R 3 in formula (1). Illustrative, non-limiting, examples of the α,β-unsaturated carboxylic esters of formula (4) include methyl acrylate, ethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, 1,1,2-trimethylpropyl acrylate, vinyl acrylate, allyl acrylate, isopropenyl acrylate, 1-cyclohexenyl acrylate, 10-undecenyl acrylate, ethynyl acrylate, methyl methacrylate, ethyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-trimethylsiloxyethyl methacrylate, 2-chloropropyl methacrylate, 3-triethylsilylpropyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-(triethoxysilyl)propyl methacrylate, 3-tris(trimethylsiloxy)silylpropyl methacrylate, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl methacrylate, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yl)propyl methacrylate, (3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)methyl methacrylate, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxan-1-yloxydimethylsilyl)propyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 1,1,2-trimethylpropyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, isobornyl methacrylate, octadecyl methacrylate, vinyl methacrylate, allyl methacrylate, isopropenyl methacrylate, 1-cyclohexenyl methacrylate, 10-undecenyl methacrylate, ethynyl methacrylate, benzyl methacrylate, phenyl methacrylate, methyl crotonate, methyl cinnamate, ethyl 4-chlorocinnamate, methyl 4-methoxycinnamate, methyl 1-cyclohexenecarboxylate, methyl cyclohexylideneacetate, 1,1,3,3,3-pentamethyl-1-[3-(methacryloyloxy)propyl]disiloxane, and α-[3-(methacryloyloxy)propyl]-ω-butyl-polydimethylsiloxane. In the process for preparing a disilyl ketene acetal according to the second embodiment of the invention, the α,β-unsaturated carboxylic ester of formula (4) is reacted with a hydrosilane or hydrosiloxane of the following general formula (2). In formula (2), R a , R b and R c are as defined above. The compounds of formulae (4) and (2) are preferably used in such amounts that up to 0.5 mole of the compound of formula (4) is present per mole of Si—H bonds on the compound of formula (2). For efficient reaction, it is preferred to use 0.45 to 0.5 mole of the compound of formula (4) per mole of Si—H bonds. In the preparation of disilyl ketene acetals according to the second embodiment of the invention, the compound of formula (4) is reacted with the compound of formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. The amount of tris(pentafluorophenyl)borane used varies with the reaction substrates although it is usually 0.00001 to 10 mol %, preferably 0.001 to 1 mol % based on the compound of formula (4). The reaction is generally effected under atmospheric pressure and in an inert gas atmosphere such as nitrogen although the process is not limited thereto. The reaction temperature is usually in the range of −100° C. to 100° C., preferably 0° C. to 60° C. Any desired mode may be used in the mixing of the substrates and the catalyst as long as attention is paid to the fact that the α,β-unsaturated carboxylic ester of formula (4) is generally polymerizable like the compound of formula (1). To control reaction conditions to suppress the possibility of polymerization, it is recommended that the reaction be performed by feeding the compound of formula (4) to a reactor charged with the catalyst and the compound of formula (2). A reaction solvent is not always necessary. Especially when both the reaction substrates (4) and (2) are liquid, the reaction can proceed in a solventless system. Of course, a solvent may be used for the reaction to take place. Suitable solvents include hydrocarbon solvents such as hexane, isooctane, benzene, toluene, and xylene, and halogenated hydrocarbon solvents such as dichloromethane and dichloroethane. A polymerization inhibitor is optionally added during the reaction. Suitable polymerization inhibitors, if used, are hindered phenols such as 2,6-di-tert-butyl-4-methylphenol (BHT) and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene. By the process in the second embodiment of the invention described above, the disilyl ketene acetals of the following general formula (5) are obtainable. In formula (5), R 5 , R 6 , R 7 , R a , R b and R c are as defined above. In the third embodiment of the invention, disilyl ketene acetals are prepared using silyl ketene acetals of the general formula (6) as the starting material. In formula (6), each of R 9 and R 10 is independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 60 carbon atoms, preferably 1 to 20 carbon atoms. Preferred unsubstituted monovalent hydrocarbon groups are those of 1 to 20 carbon atoms. The substituted monovalent hydrocarbon groups correspond to the unsubstituted monovalent hydrocarbon groups in which some or all of the hydrogen atoms bonded to carbon atoms are substituted with substituent groups. Suitable substituent groups include halogen atoms, alkoxy groups of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, organoxy groups such as alkenyloxy and aryloxy groups, silyl groups of up to 60 carbon atoms and free of a SiH bond, and organo(poly)siloxy groups of 1 to 1,000 silicon atoms, preferably 1 to 50 silicon atoms, most preferably 1 to 10 silicon atoms. Examples of the groups represented by R 9 and R 10 are as exemplified for R 1 , R 2 and R 3 in formula (1). In formula (6), a pair of R 9 and R 10 may bond together to form a ring of 3 to 20 carbon atoms, especially 5 to 12 carbon atoms, with the carbon atom to which they are attached. Suitable rings include cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclooctadiene, norbornene and indene rings. In formula (6), R 11 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 40 carbon atoms. Examples of the groups represented by R 11 are as exemplified for R 1 , R 2 and R 3 in formula (1). Illustrative, non-limiting, examples of the compounds of formula (6) include 1-methoxy-1-trimethylsiloxyethene, 1-ethoxy-1-trimethylsiloxyethene, 1-butoxy-1-trimethylsiloxyethene, 1-methoxy-1-triethylsiloxyethene, 1-methoxy-1-trimethylsiloxypropene, 1-ethoxy-1-trimethylsiloxypropene, 1-butoxy-1-trimethylsiloxypropene, 1-(2-ethylhexyloxy)-1-trimethylsiloxypropene, 1-methoxy-1-triethylsiloxypropene, 1-methoxy-1-triisobutylsiloxypropene, 1-methoxy-1-(tert-butyldimethylsiloxy)propene, 1-methoxy-1-triisopropylsiloxypropene, 1-methoxy-2-methyl-1-trimethylsiloxypropene, 1-methoxy-2-methyl-1-triethylsiloxypropene, 1-methoxy-2-methyl-1-triisobutylsiloxypropene, 1-(tert-butyldimethylsiloxy)-1-methoxy-2-methylpropene, 1-methoxy-2-methyl-1-triisopropylsiloxypropene, 1-(chlorodimethylsiloxy)-1-methoxy-2-methylpropene, 1-(3-chloropropyldimethylsiloxy)-1-methoxy-2-methylpropene, 1-(ethoxydimethylsiloxy)-1-methoxy-2-methylpropene, 1-methoxy-2-methyl-1-phenyldimethylsiloxypropene, 1-methoxy-2-methyl-1-triphenylsiloxypropene, 1-methoxy-2-methyl-1-(tert-butyldiphenyl)siloxypropene, 1-methoxy-2-methyl-1-(pentamethyldisiloxanyloxy)propene, 1-ethoxy-2-methyl-1-triethylsiloxypropene, 1-isopropoxy-2-methyl-1-triethylsiloxypropene, 1-butoxy-2-methyl-1-triethylsiloxypropene, 1-tert-butoxy-2-methyl-1-triethylsiloxypropene, 2-methyl-1-triethylsiloxy-1-vinyloxypropene, 1-benzyloxy-2-methyl-1-triethylsiloxypropene, 1-cyclohexyloxy-2-methyl-1-triethylsiloxypropene, 1-(2-ethylhexyloxy)-2-methyl-1-triethylsiloxypropene, 1-(2-trimethylsiloxyethoxy)-2-methyl-1-trimethylsiloxypropene, 1-(2-triethylsiloxyethoxy)-2-methyl-1-triethylsiloxypropene, 1-methoxy-1-triethylsiloxybutene, and 1-methoxy-3-phenyl-1-triethylsiloxypropene. In the process for preparing a disilyl ketene acetal according to the third embodiment of the invention, the silyl ketene acetal of formula (6) is reacted with a hydrosilane or hydrosiloxane of the formula (2). R a , R b and R c are as defined above. The compounds of formulae (6) and (2) may be used in any desired molar ratio. For efficient reaction, it is preferred to them in such amounts that 1.0 to 1.5 moles of Si—H bonds on the compound of formula (2) are available per mole of the compound of formula (6). In the preparation of disilyl ketene acetals according to the third embodiment of the invention, the compound of formula (6) is reacted with the compound of formula (2) in the presence of a catalytic amount of tris(pentafluorophenyl)borane. The amount of tris(pentafluorophenyl)borane used varies with the reaction substrates although it is usually 0.00001 to 10 mol %, preferably 0.001 to 1 mol % based on the compound of formula (6). The reaction is generally effected under atmospheric pressure and in an inert gas atmosphere such as nitrogen although the process is not limited thereto. The reaction temperature is usually in the range of −100° C. to 100° C., preferably 0° C. to 60° C. Any desired mode may be used in the mixing of the substrates and the catalyst. In one exemplary mode, both the substrates are premixed in a reactor, to which the catalyst is added. In another exemplary mode, one substrate and the catalyst are premixed in a reactor, to which the other substrate is fed. A reaction solvent is not always necessary. A solvent may be used for the reaction to take place. Suitable solvents that can be used herein include hydrocarbon solvents such as hexane, isooctane, benzene, toluene, and xylene, and halogenated hydrocarbon solvents such as dichloromethane and dichloroethane. By the process in the third embodiment of the invention described above, the disilyl ketene acetals of the following general formula (7) are obtainable. In formula (7), R 9 , R 10 , R a , R b , R c , R d , R e and R f are as defined above. The silyl ketene acetals of formula (3) or the disilyl ketene acetals of formulae (5) and (7) obtained by the processes of the first to third embodiments can be isolated from the reaction mixture by distillation or the like. Since the amount of by-products such as carbonyl adducts is minimized, the silyl ketene acetal having high purity can be isolated simply by distillation. It is possible to deactivate the catalyst by adding a Lewis basic compound such as triethylamine or tributylamine to the reaction mixture prior to the isolation. EXAMPLE Examples of the invention are given below by way of illustration and not by way of limitation. In all examples, reaction was performed in a nitrogen atmosphere. Example 1 Synthesis of 1-methoxy-2-methyl-1-triethylsiloxypropene Through Reaction of Methyl Methacrylate with Triethylsilane A 100-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 5.1 mg (0.01 mmol) of tris(pentafluorophenyl)borane (by Acros, lot No. A015140801, same hereinafter), 220 mg of BHT (Sumitomo Chemical Co., Ltd.) and 11.6 g (0.10 mol) of triethylsilane, which were stirred at room temperature for 0.5 hour. Using a dry ice/methanol bath, the flask was cooled to an internal temperature of −40 to −35° C. From the dropping funnel, 10.0 g (0.10 mol) of methyl methacrylate was added dropwise over 2 hours. Adjustment was made so as to maintain an internal temperature of −30 to −40° C. during the dropwise addition. Gas chromatography (GC) analysis confirmed the disappearance of methyl methacrylate after 5 minutes from the completion of dropwise addition. Neither a carbonyl adduct nor a β-adduct as shown below was detected. (Me is methyl, Et is ethyl.) After one hour from the completion of dropwise addition, the dry ice/methanol bath was removed and the flask was allowed to resume room temperature. Using a Claisen head having a Vigreux column having an inner diameter of 10 mm and a length of 10 cm, the faintly yellow, clear reaction solution was distilled in vacuo, whereby 17.4 g of a colorless clear liquid having a boiling point of 77-78° C./0.8 kPa was collected. From the results of NMR and GC/MS spectroscopy, the liquid was identified to be the title compound, 1-methoxy-2-methyl-1-triethylsiloxypropene. The yield was 80.4% and the purity was 98.8%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 3.51 (3H, s), 1.56 (3H, d, J=0.4 Hz), 1.53 (3H, d, J=0.4 Hz), 0.99 (9H, dt, J=0.7 Hz, 8.0 Hz), 0.69 (6H, dq, J=1.1 Hz, 7.9 Hz) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 149.8, 91.0, 57.1, 16.8, 16.1, 6.6, 4.9 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) 20.1 MS (EI): m/z 216 (M + ), 173, 117, 115, 89, 87, 86, 70, 59 Comparative Example 1 Synthesis of 1-methoxy-2-methyl-1-triethylsiloxypropene Through Reaction of Methyl Methacrylate with Triethylsilane in the Presence of Rhodium Trichloride Trihydrate Catalyst A 100-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 2.6 mg (0.01 mmol) of rhodium trichloride trihydrate, 22 mg of BHT and 10.0 g (0.10 mol) of methyl methacrylate. With stirring, the flask was heated in an oil bath to an internal temperature of 51° C. From the dropping funnel, 11.6 g (0.10 mol) of triethylsilane was added dropwise over 3 hours. With dropwise addition, exothermic reaction took place. Adjustment was made so as to maintain an internal temperature of 54-60° C. After the completion of dropwise addition, the reaction mixture was stirred at 56-59° C. for one hour and at 65° C. for a further one hour, whereupon methyl methacrylate disappeared. GC and GC/MS analysis of the reaction mixture showed that the desired silyl ketene acetal was obtained as a main product, and the carbonyl adduct and β-adduct were additionally formed. The ratio silyl ketene acetal/carbonyl adduct/β-adduct of the products was 1:0.081:0.002 (TCD, GC area %). Using the same system as in Example 1, the reaction mixture was distilled in vacuo, whereby 18.1 g of a colorless clear fraction having a boiling point of 79-79.5° C./0.85 kPa was collected. On GC (TCD) analysis, the fraction had the following composition. silyl ketene acetal: 94.5% carbonyl adduct: 4.1% β-adduct: 0% others: 1.4% The result indicates the difficulty to isolate the title compound to high purity by distillation. Example 2 Synthesis of 1,3-bis(1-methoxy-2-methyl-1-propenyloxy)-1,1,3,3-tetramethyldisiloxane Through Reaction of Methyl Methacrylate with 1,1,3,3-tetramethyldisiloxane A 100-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 258 mg of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene (I-1330, Ciba Specialty Chemicals, same hereinafter), 5 mL of toluene and 0.5 mg (0.001 mmol) of tris(pentafluorophenyl)borane. With stirring, the flask was cooled to 2° C. in an ice water bath. From the dropping funnel, a mixture of 20.0 g (0.20 mol) of methyl methacrylate and 13.4 g (0.10 mol) of 1,1,3,3-tetramethyldisiloxane was added dropwise over 4 hours. During the period, the internal temperature rose to 7.5° C. at maximum. After the completion of dropwise addition, the reaction mixture was stirred at 2-4° C. for 1.5 hours whereupon methyl methacrylate disappeared. The reaction mixture was distilled in vacuo, whereby 26.5 g of a colorless clear fraction having a boiling point of 96-97.5° C./0.2 kPa was collected. From the results of NMR and GC/MS analysis, the liquid was identified to be the title compound, 1,3-bis(1-methoxy-2-methyl-1-propenyloxy)-1,1,3,3-tetramethyldisiloxane. The yield was 79.1%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 3.51 (6H, s), 1.56 (6H, d, J=0.4 Hz), 1.52 (6H, d, J=0.4 Hz), 0.20 (12H, s) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 148.7, 91.0, 56.6, 16.8, 16.1, −0.7 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) −12.2 MS (EI): m/z 334 (M + ), 233, 217, 179, 163, 133 Example 3 Synthesis of 2-methyl-1-triethylsiloxy-1-vinyloxypropene Through Reaction of Vinyl Methacrylate with Triethylsilane A 100-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 258 mg of I-1330, 7.7 mg (0.015 mmol) of tris(pentafluorophenyl)borane and 11.6 g (0.10 mol) of triethylsilane, which were stirred at room temperature for 0.5 hour. The flask was cooled in an ice water bath to an internal temperature of 1.5° C. From the dropping funnel, 11.2 g (0.10 mol) of vinyl methacrylate was added dropwise over 2.5 hours. During the period, the internal temperature rose to 6.5° C. at maximum. After the completion of dropwise addition, the reaction mixture was stirred at 2° C. for 2 hours and with the ice water bath removed, at 15-20° C. for a further 5 hours. The reaction mixture was distilled in vacuo, whereby 19.3 g of a colorless clear fraction having a boiling point of 79.5-80° C./0.8 kPa was collected. From the results of NMR and GC/MS analysis, the liquid was identified to be the title compound, 2-methyl-1-triethylsiloxy-1-vinyloxypropene. The yield was 84.5%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 6.34 (1H, dd, J=6.3 Hz, 14.0 Hz), 4.49 (1H, dd, J=1.8 Hz, 14.0 Hz), 4.15 (1H, dd, J=1.8 Hz, 6.3 Hz), 1.58 (3H, d, J=0.4 Hz), 1.53 (3H, d, J=0.4 Hz), 0.98 (9H, dt, J=0.7 Hz, 7.9 Hz), 0.68 (6H, dq, J=1.2 Hz, 7.9 Hz) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 149.2, 146.3, 93.0, 90.7, 16.7, 16.1, 6.5, 5.0 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) 21.9 MS (EI): m/z 228 (M + ), 213, 115, 87, 70, 59 Example 4 Synthesis of 1-tert-butoxy-2-methyl-1-triethylsiloxypropene Through Reaction of Tert-butyl Methacrylate with Triethylsilane A 100-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 258 mg of I-1330, 7.7 mg (0.015 mmol) of tris(pentafluorophenyl)borane and 11.6 g (0.10 mol) of triethylsilane, which were stirred at room temperature for 0.5 hour. The flask was cooled in an ice water bath to an internal temperature of 3.5° C. From the dropping funnel, 13.5 g (0.095 mol) of tert-butyl methacrylate was added dropwise over 2.5 hours. During the period, the internal temperature rose to 6° C. at maximum. After the completion of dropwise addition, the reaction mixture was stirred at 3-3.5° C. for 3 hours whereupon triethylsilane disappeared as confirmed by GC analysis. The reaction mixture contained a small amount of white solids. The reaction mixture was distilled in vacuo, whereby 24.8 g of a colorless clear fraction having a boiling point of 73-75° C./0.3 kPa was collected. From the results of NMR and MS analysis, the liquid was identified to be the title compound, 1-tert-butoxy-2-methyl-1-triethylsiloxypropene. The yield based on triethylsilane was 81.5%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 1.55 (3H, d, J=0.4 Hz), 1.54 (3H, d, J=0.4 Hz), 1.27 (9H, s), 0.98 (9H, dt, J=0.6 Hz, 7.8 Hz), 0.69 (6H, dq, J=1.1 Hz, 7.9 Hz) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 146.7, 95.6, 78.9, 29.1, 18.2, 17.5, 6.7, 5.2 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) 20.1 MS (EI): m/z 258 (M + ), 229, 202, 173, 157, 133, 115, 103, 87, 75, 70, 57, 41 Example 5 Synthesis of 2-methyl-1-triethylsiloxy-1-trimethylsiloxypropene Through Reaction of Trimethylsilyl Methacrylate with Triethylsilane A 200-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 258 mg of I-1330, 5.1 mg (0.01 mmol) of tris(pentafluorophenyl)borane and 11.6 g (0.10 mol) of triethylsilane, which were stirred at room temperature for 15 minutes. The flask was cooled in an ice water bath to an internal temperature of 4.5° C. From the dropping funnel, 11.1 g (0.07 mol) of trimethylsilyl methacrylate was added dropwise over 4 hours. During the period, the internal temperature rose to 8° C. at maximum. A toluene solution of 3 mg (0.006 mmol) of tris(pentafluorophenyl)borane was added to the flask. From the dropping funnel, 4.7 g (0.03 mol) of trimethylsilyl methacrylate was then added dropwise over one hour. After the completion of dropwise addition, the reaction mixture was stirred at 5° C. for 9 hours whereupon triethylsilane disappeared as confirmed by GC analysis. The reaction mixture, to which 22 μL (0.16 mmol) of triethylamine was added, was stirred for 0.5 hour. Cooling was then stopped and the mixture allowed to warm to room temperature. The reaction mixture containing a small amount of white solids was distilled in vacuo, whereby 13.5 g of a colorless clear fraction having a boiling point of 69-71° C./0.4 kPa was collected. From the results of NMR and MS analysis, the liquid was identified to be the title compound, 2-methyl-1-triethylsiloxy-1-trimethylsiloxypropene. The yield was 49.2%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 1.53 (3H, s), 1.49 (3H, s), 0.98 (9H, t, J=7.9 Hz), 0.68 (6H, q, J=7.9 Hz), 0.18 (9H, s) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 145.0, 87.7, 17.4, 17.2, 6.7, 5.1, 0.4 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) 20.6, 19.6 MS (EI): m/z 274 (M + ), 259, 231, 175, 147, 119, 115, 87, 86, 73, 59 Example 6 Synthesis of 1,1-bis(triethylsiloxy)-2-methylpropene Through Reaction of Methyl Methacrylate with Triethylsilane A 200-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 1.9 mg (0.00375 mmol) of tris(pentafluorophenyl)borane, 17.4 g (0.15 mol) of triethylsilane and 581 mg of I-1330, which were stirred at room temperature for 15 minutes. Using an ice bath, the flask was cooled to an internal temperature of 1.5° C. From the dropping funnel, 7.5 g (0.075 mol) of methyl methacrylate was added dropwise over 2.5 hours. During the period of dropwise addition, exothermic reaction took place and the internal temperature rose to 7° C. at maximum. Gas chromatography (GC) analysis confirmed the disappearance of methyl methacrylate after 5 minutes from the completion of dropwise addition. After 2 hours, the ice bath was removed, and the reaction mixture was stirred at room temperature for 18 hours. To the reaction mixture was added 10.5 μL (0.075 mmol) of triethylamine. On GC/MS analysis of the reaction mixture, the main product was the title compound, and none of a carbonyl adduct, a β-adduct as shown below, and derivatives thereof were detected. (Me is methyl, Et is ethyl.) Using a Claisen head having a Vigreux column having an inner diameter of 10 mm and a length of 10 cm, the reaction mixture was distilled in vacuo, whereby 17.9 g of a colorless clear liquid having a boiling point of 108.5-109° C./0.2 kPa was collected. From the results of NMR and GC/MS spectroscopy, the liquid was identified to be the title compound, 1,1-bis(triethylsiloxy)-2-methylpropene. The yield was 75.4% and the purity was >99.9%. 1 H-NMR (CDCl 3 , 300 MHz): δ (ppm) 1.50 (6H, s), 0.98 (18H, t, J=7.9 Hz), 0.67 (12H, q, J=7.9 Hz) 13 C-NMR (CDCl 3 , 75.6 MHz): δ (ppm) 145.2, 87.1, 17.4, 6.7, 5.1 29 Si-NMR (CDCl 3 , 59.7 MHz): δ (ppm) 20.6 MS (EI): m/z 316 (M + ), 259, 217, 189, 173, 115, 87, 59 Example 7 Synthesis of 1,1-bis(triethylsiloxy)-2-methylpropene Through Reaction of 1-methoxy-2-methyl-1-triethylsiloxypropene with Triethylsilane A 200-mL four-necked flask equipped with a Dimroth reflux condenser, stirrer, thermometer and dropping funnel was purged with nitrogen. The flask was charged with 388 mg of I-1330, 1.28 mg (0.0025 mmol) of tris(pentafluorophenyl)borane and 5.8 g (0.05 mol) of triethylsilane, which were stirred at room temperature for 15 minutes. Using an ice water bath, the flask was cooled to an internal temperature of 5° C. From the dropping funnel, 10.8 g (0.050 mol) of 1-methoxy-2-methyl-1-triethylsiloxypropene was added dropwise over 3 hours. During the period, the internal temperature rose to 9° C. at maximum. After the completion of dropwise addition, the reaction mixture was stirred at 5° C. for 4 hours and then at room temperature for a further 12 hours. On GC/MS analysis, the formation of the title compound was confirmed. The reaction mixture, to which 9.8 μL (0.07 mmol) of triethylamine was added, was stirred for 0.5 hour and then distilled in vacuo. 11.0 g of a colorless clear fraction having a boiling point of 91-91.5° C./0.13 kPa was collected. From the results of NMR and MS analysis, the liquid was identified to be the title compound, 1,1-bis(triethylsiloxy)-2-methylpropene. The yield was 69.5%. Japanese Patent Application No. 2003-121366 is incorporated herein by reference. Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.

By reacting α,β-unsaturated carboxylic esters with hydrosilanes or hydrosiloxanes in the presence of a catalytic amount of tris(pentafluorophenyl)borane, silyl ketene acetals or disilyl ketene acetals with high purity are produced in high yields.

[0001] The present invention relates to novel heterocyclic compounds, to methods for their preparation, to compositions containing them, and to methods and use for clinical treatment of medical conditions which may benefit from immunomodulation, including rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis. More particularly the present invention relates to novel heterocyclic compounds, which are CD80 antagonists capable of inhibiting the interactions between CD80 and CD28. BACKGROUND OF THE INVENTION [0002] The immune system possesses the ability to control the homeostasis between the activation and inactivation of lymphocytes through various regulatory mechanisms during and after an immune response. Among these are mechanisms that specifically inhibit and/or turn off an immune response. Thus, when an antigen is presented by MHC molecules to the T-cell receptor, the T-cells become properly activated only in the presence of additional co-stimulatory signals. In the absence of accessory signals there is no lymphocyte activation and either a state of functional inactivation termed anergy or tolerance is induced, or the T-cell is specifically deleted by apoptosis. One such co-stimulatory signal involves interaction of CD80 on specialised antigen-presenting cells with CD28 on T-cells, which has been demonstrated to be essential for full T-cell activation. (Lenschow et al. (1996) Annu. Rev. Immunol., 14, 233-258) [0003] A paper by Erbe et al, in J. Biol. Chem. Vol. 277, No. 9, pp 7363-7368 (2002), describes three small molecule ligands which bind to CD80, and inhibit binding of CD80 to CD28 and CTLA4. Two of the disclosed ligands are fused pyrazolones of structures A and B: DESCRIPTION OF THE INVENTION [0004] According to the present invention there is provided a compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof: wherein R 1 and R 3 independently represent H; F; Cl; Br; —NO 2 ; —CN; C 1 -C 6 alkyl optionally substituted by F or Cl; or C 1 -C 6 alkoxy optionally substituted by F; R 2 represents H, or optionally substituted C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or optionally substituted phenyl; Y represents —O—, —S—, N-oxide, or —N(R 5 )— wherein R 5 represents H or C 1 -C 6 alkyl; X represents a bond or a divalent C 1 -C 6 alkylene radical; R 4 represents —C(═O)NR 6 R 7 , —NR 7 C(═O)R 6 , —NR 7 C(═O)OR 6 , —NHC(═O)NHR 6 , or —NHC(═S)NHR 6 wherein R 6 represents H, or a radical of formula -(Alk)b-Q wherein b is 0 or 1, and Alk is an optionally substituted divalent straight chain or branched C 1 -C 12 alkylene, C 2 -C 12 alkenylene or C 2 -C 12 alkynylene radical which may be interrupted by one or more non-adjacent —O—, —S— or —N(R 8 )— radicals wherein R 8 represents H or C 1 -C 4 alkyl, C 3 -C 4 alkenyl, C 3 -C 4 alkynyl, or C 3 -C 6 cycloalkyl, and Q represents H; —CF 3 ; —OH; —SH; —NR 8 R 8 wherein each R 8 may be the same or different; an ester group; or an optionally substituted phenyl, C 3 -C 7 cycloalkyl, C 5 -C 7 cycloalkenyl or heterocyclic ring having from 5 to 8 ring atoms; and R 7 represents H or C 1 -C 6 alkyl; or when taken together with the atom or atoms to which they are attached R 6 and R 7 form an optionally substituted heterocyclic ring having from 5 to 8 ring atoms. [0014] Compounds of general formula (I) are CD80 antagonists. They inhibit the interaction between CD80 and CD28 and thus the activation of T cells, thereby modulating the immune response. [0015] Accordingly the invention also includes: [0016] (i) a compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof for use in the treatment of conditions which benefit from immunomodulation. [0017] (ii) the use of a compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof in the manufacture of a medicament for the treatment of conditions which benefit from immunomodulation,. [0018] (iii) a method of immunomodulation in humans and non-human primates, comprising administration to a subject in need of such treatment an immunomodulatory effective dose of a compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof. [0019] (iv) a pharmaceutical or veterinary composition comprising a compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof together with a pharmaceutically or veterinarily acceptable excipient or carrier. [0020] Conditions which benefit from immunomodulation include: Adrenal insufficiency Allergic angiitis and granulomatosis Amylodosis Ankylosing spondylitis Asthma Autoimmune Addison's disease Autoimmune alopecia Autoimmune chronic active hepatitis Autoimmune hemolytic anemia Autoimmune neutropenia Autoimmune thrombocytopenic purpura Autoimmune vasculitides Behcet's disease Cerebellar degeneration Chronic active hepatitis Chronic inflammatory demyelinating polyradiculoneuropathy Dermatitis herpetiformis Diabetes Eaton-Lambert myasthenic syndrome Encephalomyelitis Epidermolysis bullosa Erythema nodosa Gluten-sensitive enteropathy Goodpasture's syndrome Graft versus host disease Guillain-Barre syndrome Hashimoto's thyroiditis Hyperthyrodism Idiopathic hemachromatosis Idiopathic membranous glomerulonephritis Minimal change renal disease Mixed connective tissue disease Multifocal motor neuropathy Multiple sclerosis Myasthenia gravis Opsoclonus-myoclonus syndrome Pemphigoid Pemphigus Pernicious anemia Polyarteritis nodosa Polymyositis/dermatomyositis Post-infective arthritides Primary biliary sclerosis Psoriasis Reactive arthritides Reiter's disease Retinopathy Rheumatoid arthritis Sclerosing cholangitis Sjögren's syndrome Stiff-man syndrome Subacute thyroiditis Systemic lupus erythematosis Systemic sclerosis (scleroderma) Temporal arteritis Thromboangiitis obliterans Transplantation rejection Type I and type II autoimmune polyglandular syndrome Ulcerative colitis Uveitis Wegener's granulomatosis [0082] As used herein the term “alkylene” refers to a straight or branched alkyl chain having two unsatisfied valencies, for example —CH 2 —, —CH 2 CH 2 —, —CH 2 CH 2 CH 2 —, —CH(CH 3 )CH 2 —, —CH(CH 2 CH 3 )CH 2 CH 2 CH 3 , and —C(CH 3 ) 3 . [0083] As used herein the term “heteroaryl” refers to a 5- or 6-membered aromatic ring containing one or more heteroatoms. Illustrative of such groups are thienyl, furyl, pyrrolyl, imidazolyl, benzimidazolyl, thiazolyl, pyrazolyl, isoxazolyl, isothiazolyl, triazolyl, thiadiazolyl, oxadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl. [0084] As used herein the unqualified term “heterocyclyl” or “heterocyclic” includes “heteroaryl” as defined above, and in particular means a 5-8 membered aromatic or non-aromatic heterocyclic ring containing one or more heteroatoms selected from S, N and O, including for example, pyrrolyl, furanyl, thienyl, piperidinyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl, pyrazolyl, pyridinyl, pyrrolidinyl, pyrimidinyl, morpholinyl, piperazinyl, indolyl, morpholinyl, benzofuranyl, pyranyl, isoxazolyl, quinuclidinyl, aza-bicyclo[3.2.1]octanyl, benzimidazolyl, methylenedioxyphenyl, maleimido and succinimido groups. [0085] Unless otherwise specified in the context in which it occurs, the term “substituted” as applied to any moiety herein means substituted with one or more of the following substituents, namely (C 1 -C 6 )alkyl, trifluoromethyl, (C 1 -C 6 )alkoxy (including the special case where a ring is substituted on adjacent ring C atoms by methylenedioxy or ethylenedioxy), trifluoromethoxy, (C 1 -C 6 )alkylthio, phenyl, benzyl, phenoxy, (C 3 -C 8 )cycloalkyl, hydroxy, mercapto, amino, fluoro, chloro, bromo, cyano, nitro, oxo, —COOH, —SO 2 OH, —CONH 2 , —SO 2 NH 2 , —COR A , —COOR A , —SO 2 OR A , —NHCOR A , —NHSO 2 R A , —CONHR A , —SO 2 NHR A , —NHR A , —NR A R B , —CONR A R B or —SO 2 NR A R B wherein R A and R B are independently a (C 1 -C 6 )alkyl group. In the case where “substituted” means substituted by (C 3 -C 8 )cycloalkyl, phenyl, benzyl or phenoxy, the ring thereof may itself be substituted with any of the foregoing, except (C 3 -C 8 )cycloalkyl phenyl, benzyl or phenoxy. [0086] As used herein the unqualified term “carbocyclyl” or “carbocyclic” refers to a 5-8 membered ring whose ring atoms are all carbon. [0087] Some compounds of the invention contain one or more chiral centres because of the presence of asymmetric carbon atoms. The presence of asymmetric carbon atoms gives rise to stereoisomers or diastereoisomers with R or S stereochemistry at each chiral centre. The invention includes all such stereoisomers and diastereoisomers and mixtures thereof. [0088] Salts of salt forming compounds of the invention include physiologically acceptable acid addition salts for example hydrochlorides, hydrobromides, sulphates, methane sulphonates, p-toluenesulphonates, phosphates, acetates, citrates, succinates, lactates, tartrates, fumarates and maleates; and base addition salts, for example sodium, potassium, magnesium, and calcium salts. Where the compound contains an amino group, quaternary amino salts are also feasable, and are included in the invention. [0089] In the compounds of the invention the following are examples of the several structural variables: R 1 may be, for example, H, F, Cl, methyl, methoxy, or methylenedioxy. Currently it is preferred that R 1 is H, Cl or especially F; R 2 may be, for example H, methyl, methoxy, cyclopropyl, phenyl, or fluoro-, chloro-, methyl, or methoxy-substituted phenyl. H or cyclopropyl is presently preferred; R 3 may be, for example, H, F, Cl, methyl, methoxy, or methylenedioxy. Currently it is preferred that R 3 is F or Cl, and it is most preferred that R 3 be H; Y may be, for example, —O—, —S—, or —N(R 5 )— wherein R 5 represents H or methyl. —NH— or —S— is presently preferred. X may be, for example a bond, or a —CH 2 — or —CH 2 CH 2 — radical. A bond is presently preferred. R 4 represents —C(═O)NR 6 R 7 , —NR 7 C(═O)R 6 , —NR 7 C(═O)OR 6 , —NHC(═O)NHR 6 , or —NHC(═S)NHR 6 . Of these —NR 7 C(═O)R 6 , and especially —C(═O)NR 6 R 7 and —NHC(═O)NHR 6 are curently preferred. R 7 is preferably H, but a wide range of R 6 substituents have given rise to highly active compounds of the invention. Many exemplary R 6 substituents appear in the compounds of the Examples below. R 6 may be, for example, H or a radical of formula -Alk b -Q wherein b is 0 or 1 and Alk may be, for example a —(CH 2 ) n —, —CH((CH 2 ) m CH 3 )(CH 2 ) n —, —C((CH 2 ) m CH 3 )((CH 2 ) p CH 3 ) (CH 2 ) n —, —(CH 2 ) n —O—(CH 2 ) m —, —(CH 2 ) n —NH—(CH 2 ) m —, or —(CH 2 ) n —NH—(CH 2 ) m —NH—(CH 2 ) p — radical where n is 1, 2, 3 or 4 and m and p are independently 0, 1, 2, 3 or 4, and Q may represent H, —OH, —COOCH 3 , phenyl, cyclopropyl, cyclopentyl, cyclohexyl, pyridyl, furyl, thienyl, or oxazolyl; and R 7 may be, for example, H, or when taken together with the atom or atoms to which they are attached R 6 and R 7 may form a heterocyclic ring of 5, 6 or 7 members. [0100] Specific examples of R 4 groups include those present in the compounds of the Examples herein. [0101] Compounds of the invention may be prepared by synthetic methods known in the literature, from compounds which are commercially available or are accessible from commercially available compounds. For example, compounds of formula (I) wherein R 4 is a group —NR 7 C(═O)R 6 may be prepared by acylation of an amine of formula (II) with an acid chloride of formula (III): [0102] Compounds of the invention wherein R 4 is a group —NHC(═O)NHR 6 may be prepared by reaction of an amine of formula (IIA) with an isocyanate of formula (IIIA) [0103] Compounds of the invention wherein R 4 is a group —C(═O)NHR 6 may be prepared by reaction of an acid chloride of formula (IIB) with an amine NHR 6 R 7 : [0104] Compounds of the invention wherein R 4 is a group —NR 7 C(═O)OR 6 may be prepared by reaction of an amine of formula (II) with a chloroformate ClC(═O)OR 6 . [0105] The following Examples illustrate the preparation of compounds of the invention: Preparation of Intermediate 1 2-(4-Nitrophenyl)-6-fluoro-2,5-dihydropyrazolo[4,3-c]-quinolin-3-one [0106] [0107] 4-Nitrophenylhydrazine (2.28 g, 0.014 mol) was added in one portion to a stirred solution of 4-chloro-8-fluoro-quinoline-3-carboxylic acid ethyl ester (3.58 g, 0.014 mol) in anhydrous n-butyl alcohol (50 ml) at room temperature. The mixture was refluxed for 16 h under nitrogen, cooled to room temperature and then filtered to leave an orange solid. The solid was purified by washing sequentially with ethyl acetate (20 ml) and heptane (20 ml) and then finally dried under suction to give the pyrazolone (3.93 g, 87%) as a dark orange solid, LCMS m/z 325.24 [M+H] + @ R T 1.47 min. Preparation of Intermediate 2 2-(4-Aminophenyl)-6-fluoro-2,5-dihydropyrazolo[4,3-c]-quinolin-3-one [0108] [0109] Tin (II) chloride dihydrate (12.5 g, 0.055 mol) was added in one portion to a stirred solution of 2-(4-nitro-phenyl)-6-fluoro-2,5-dihydro-pyrazolo[4,3-c]quinolin-3-one (intermediate 1) (3.59 g, 0.011 mol) in ethyl alcohol (110 ml) at room temperature. The mixture was then heated to 80° C. for 8 h, cooled to room temperature and filtered to leave a yellow solid. The solid was suspended in a bi-phasic solution of ethyl acetate (1L), a saturated solution of Rochelles salt (500 ml) and a saturated solution of sodium bicarbonate (500 ml) and stirred at room temperature for 2 h. The mixture was filtered and the remaining solid was washed with water and dried under vacuum to afford the title compound (3.39 g, 99%) as a bright yellow solid, LCMS m/z 295.30 [M+H] + @ R T 0.84 min. EXAMPLE 1 N-[4-(6-Fluoro-3-oxo-3,5-dihydropyrazolo[4,3-c]quinolin-2-yl)-phenyl]-2-methyl-butyramide [0110] [0111] (±)-2-Methylbutyryl chloride (13.6 μl, 0.11 mmol) was added dropwise over 30 sec to a stirred solution of 2-(4-amino-phenyl)-6-fluoro-2,5-dihydro-pyrazolo[4,3-c]quinolin-3-one (Intermediate 2) (30 mg, 0.10 mmol), triethylamine (14 μl, 0.11 mmol) and 4-dimethylaminopyridine (2.4 mg, 0.02 mmol) in dichloromethane (1 ml) at room temperature. The mixture was stirred at room temperature for 16 h. The yellow solid was then filtered and purified by washing sequentially with a saturated solution of sodium bicarbonate (1 ml), ethyl acetate (1 ml) and ethyl alcohol (0.5 ml) and finally dried under suction to give the title compound (10 mg, 26%) as a bright yellow solid, LCMS m/z 379.36 [M+H] + @ R T 1.18 min. δ H (400 MHz, (CD 3 ) 2 SO) 9.89 (1H, s), 8.52 (1H, s), 8.15 (2H, d J 9.0 Hz), 8.01 (1H, d J 7.0 Hz), 7.69 (2H, d J 9.0 Hz) 7.57-7.46 (2H, m), 2.46-2.39 (1H, m), 1.69-1.36 (2H, m), 1.11 (3H, d J 6.8 Hz), 0.91(3H, t J 7.3 Hz). [0112] The title compound, and compounds of subsequent Examples, were tested in the assay described below in the Assay Section, to determine their activities as inhibitors of the CD80-CD28 interaction. The present title compound had an activity rating of ***. EXAMPLES 2-49 [0113] The following compounds were synthesized by the route described in Example 1, substituting the appropriate acid chloride for (±)-2-methylbutyryl chloride: EXAMPLE 2 2-Methyl-pentanoic acid [4-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-amide [0114] [0115] δ H (400 MHz, (CD 3 ) 2 SO) 9.92 (1H, s), 8.53 (1H, s) 8.12 (2H, d J 9.2 Hz), 8.05 (1H, d J 7.6 Hz), 7.70 (2H, d J 9.2 Hz), 7.63-7.53 2H, m), 1.68-1.58 (1H, m), 1.38-1.28 (3H, m), 1.11 (3H, d J 6.6 Hz), 0.91 (3H, t J 7.1 Hz). Activity *** EXAMPLE 3 1-Methyl-1H-pyrrole-2-carboxylic acid [4-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-amide [0117] [0118] δ H (400 MHz, (CD 3 ) 2 SO) 9.76 (1H, s), 8.50 (1H, s), 8.26 (2H, d 9.0 Hz), 7.97-7.94 (1H, m), 7.73 (2H, d J 9.0 Hz), 7.39-7.28 (2H, m), 7.07-7.01 (2H, m), 3.91 (3H, s) Activity * EXAMPLE 4 N-[4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-3-methyl-butyramide [0120] [0121] δ H (400 MHz, (CD 3 ) 2 SO) 9.92 (1H, s), 8.52 (1H, s), 8.14 (2H, d J 9.2 Hz), 8.01 (1H, d J 7.3 Hz), 7.67 (2H, d J 9.2 Hz), 7.57-7.47 (2H, m), 2.21 (2H, d J 6.8 Hz), 2.14-2.07 (1H, m), 0.96 (6H, d J 6.6 Hz). Activity ** EXAMPLE 5 2-Propyl-pentanoic acid [4-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-amide [0123] [0124] δ H (400 MHz, (CD 3 ) 2 SO) 9.93 (1H, s), 8.53 (1H, s), 8.11 (2H, d J 9.0 Hz), 8.05 (1H, d J 7.8 Hz), 7.70 (2H, d J 9.0 Hz), 7.59-7.46 (2H, m), 2.46-2.35 (1H, m), 1.63-1.27 (4H, m), 0.90(6H, t J 7.1 Hz). Activity * EXAMPLE 6 5-[4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)phenylcarbamoyl]-pentanoic acid methyl ester [0126] [0127] δ H (400 MHz, (CD 3 ) 2 SO) 9.85 (1H, s), 8.47 (1H, s), 8.25 (2H, d J 9.0 Hz), 7.91-7.90 (1H, m), 7.59 (2H, d J 9.0 Hz), 7.29-7.20 (2H, m), 3.61 (3H, s), 2.38-2.28 (4H, m), 1.64-1.50 (4H, m) Activity *** EXAMPLE 7 N-[4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-2,2-dimethyl-propionamide [0129] [0130] δ H (400 MHz, (CD 3 ) 2 SO) 9.26 (1H, S), 8.52 (1H, s), 8.15 (2H, d J 9.2 Hz), 8.03 (1H, d J 8.8 Hz), 7.71 (2H, d J 9.2 Hz), 7.56-7.47 (2H, m), 1.26 (9H, s) Activity ** [0132] Examples 8 to 28 were also prepared by the method of Example 1 using the appropriate acid chloride: M.S. Example X R (MH+) Activity 8 6-F 443.4 ** 9 6-F —CH 2 Cl 371.31 ** 10 6-F 389.34 * 11 6-F 485.45 * 12 6-F CO 2 Me 381.34 ** 13 6-F OEt 367.18 14 6-F 507.43 * 15 6-F 466.41 ** 16 6-F Me 337.36 ** 17 6-F CH(Et)CH 2 CH 2 CH 2 Me 421.46 * 18 6-F CH(Et) 2 393.41 *** 19 6-F 405.41 ** 20 6-F 448.44 ** 21 6-F 481.35 ** 22 6-F 423.42 *** 23 6-F (CH 2 ) 8 CO 2 Me 493.51 ** 24 6-F iPr 365.36 *** 25 6-F CH 2 OCH 2 CH 2 OMe 411.4 ** 26 6-F CH(Me) (nPr) 393.42 *** 27 6-F CH 2 OMe 367.24 ** 28 6-F 390.33 ** 29 6-F CH 2 CH 2 CH 2 N + (Me) 3 422.1 (M+) *** 30 6-F CH 2 CH 2 CH 2 N(Me) 2 408.3 *** 31 6-F CH 2 NHCH 2 CH 2 CH 2 N(Me) (Ph) 499.3 * 32 6-F 485.3 * 33 6-F 505.1 *** 34 6-F 517.2 *** 35 6-F 477.1 *** 36 6-F 457.1 ** 37 6-F 463.1 ** 38 6-F 438.3 ** 39 6-F 463.2 *** 40 6-F 460.4 ** 41 6-F CH 2 NHCH 2 CH 2 N(iPr) 2 479.4 ** 42 6-F 420.2 ** 43 H CH(NH 2 )CH 3 348.3 ** 44 H CH(Me)nPr 375.3 * 45 H iPr 347.3 ** 46 6-F CH(NH 2 )CH 3 366.3 *** 47 H CH(Me)Et 361.3 ** 48 6-F 529.1 ** 49 6-F CH 2 N(Me)CH 2 Ph 456.4 ** Preparation of Intermediate 3 3-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid [0133] [0134] 3-Hydrazinobenzoic acid (1.91 g, 0.013 mol) was added in one portion to a stirred solution of 4-chloro-8-fluoro-quinoline-3-carboxylic acid ethyl ester (2.93 g, 0.011 mol) in n-butanol (60 ml) at room temperature. The solution was heated to reflux for 16 h, cooled to room temperature and the resulting yellow solid filtered, washed with tert-butyl methyl ether and then dried. The solid was redissolved in a solution of tetrahydrofuran:water (2:1; 21 ml) and lithium hydroxide (1.27 g, 0.031 mol) was then added. After stirring at room temperature for 16 h, concentrated hydrochloric acid (3 ml) was added dropwise to the mixture to precipitate a yellow solid which was filtered and dried under vacuum to give the title compound (intermediate 3) (2.32 g, 63%) as a bright yellow solid. Preparation of Intermediate 4 3-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoyl chloride [0135] [0136] Oxalyl chloride (20 ml, 0.2 mol) was added dropwise over 2 min to a stirred solution of 3-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid (intermediate 3) (2.0 g, 6.1 mmol) in dichloromethane (10 ml) at room temperature. N,N-Dimethylformamide (50 μl) was then added and the resulting mixture heated to 50° C. for 1 h. The solution was then cooled to room temperature and then concentrated in vacuo to leave the title compound (intermediate 4) (2.0 g, 96%) as a beige solid. EXAMPLE 50 3-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-N-(3-methoxy-propyl)-benzamide [0137] [0138] 3-Methoxypropylamine (0.026 g, 0.29 mmol) was added to a stirred solution of 3-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoyl chloride (intermediate 4) (26 mg 0.29 mmol) in tetrahydrofuran (2 ml) and the mixture stirred at room temperature for 15 min. Triethylamine (0.2 ml, 1.4 mmol) was then added and the resulting mixture stirred overnight. 1 M Hydrochloric acid (3-4 ml) was added dropwise to precipitate a yellow solid which was filtered and dried under suction to give the amide (79 mg, 0.20 mmol) as a yellow solid, LCMS m/z 395.25 [M+H] + @ R T 1.04 min; δ H (400 MHz, (CD 3 ) 2 SO) 8.59 (1H, m), 8.57 (1H, s), 8.39 (1H, app d J 9.3 Hz), 8.08 (1H, app d J 7.3 Hz), 7.66-7.53 (5H, m), 3.37-3.33 (4H, m), 3.27 (3H, s), 1.83-1.77 (2H, m). Activity ** EXAMPLE 51 N-Ethyl-3-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]-quinolin-2-yl)-benzamide [0140] [0141] Prepared by the method of Example 53 substituting ethylamine for 3-methoxypropylamine. [0142] δ H (400 MHz, (CD 3 ) 2 SO) major rotomer quoted; 8.56 (1H, br s), 8.47 (1H, m), 8.21 (2H, d J 8.5 Hz), 7.94 (2H, d J 8.5 Hz), 3.96 (3H, s), 3.31 (2H, q J 7.3 Hz), 2.58 (3H, s), 1.15 (3H, t J 7.4 Hz). Activity ** EXAMPLE 52 N-Benzyl-3-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]-quinolin-2-yl)-benzamide [0144] [0145] Prepared by the method of Example 53 substituting benzylamine for 3-methoxypropylamine. [0146] LCMS m/z 427.16 [M+H] + @ R T 1.28 min. Activity * [0148] Examples 53 to 64 were prepared by the method of example 50, using the appropriate amine. M.S. Example X R R′ (MH+) Activity 53 6-F CH 2 CH 2 CH 2 N(Me) 2 Me 422.5 * 54 6-F CH 2 CH 2l CH 2 N(Me) 2 H 408.4 ** 55 6-F H 420.4 * 56 6-F H 434.4 * 57 6-F H 448.4 ** 58 6-F CH 2 CH 2 CH 2 CH 2 N(Me) 2 H 422.4 ** 59 6-F CH 2 CH 2 OMe H 381.3 ** 60 6-F Et Et 379.3 * 61 6-F CH 2 CO 2 Me H 395.2 * 62 6-F CH 2 CCH H 361.3 ** 63 6-F CH 2 Ph Me 427.2 ** 64 6-F 463.3 * EXAMPLE 65 N-(3-Dimethylamino propyl)-4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c)quinolin-2-yl]-benzamide Step 1 2-cyclopropyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester [0149] [0150] A solution of 3-cyclopropyl-3-oxo-propionic acid methyl ester (6.2 g, 0.038 mols), 2-amino benzoic acid ethyl ester (4.95 g, 0.03 mols) and p-toluene sulfonic acid (0.04 g, 0.2 mmols) in toluene (25 ml) was heated at 125° C. for 2 h; 15 ml of solvent was then distilled. To the residual orange solution was added sodium ethoxide (2 M, 15 ml) in ethanol (reaction mixture turns red). This red mixture was stirred at 120° C. for 2 h; 15 ml of solvent was again distilled. The reaction mixture was left to cool to room temperature, diluted with ethyl acetate (1 litre), extracted with HCl 0.1 M and water. The combined organic extracts were dried over sodium sulfate and concentrated in vacuo to leave an orange residue which was washed once with cold ethyl acetate to yield 2-cyclo-propyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester (3.87 g, 53%) as an off-white solid. LCMS m/z 244.14 [M+H] + @ R T 0.78 min, 89%, m/z 230.11 [Acid+H] + @ R T 1.27, 11%. [0151] δ H (400 MHz, (CD 3 ) 2 SO) 11.04 (1 H, s), 8.06 (1 H, dd, J 1 1.1, J 2 8.1), 7.76-7.66 (2 H, m), 7.36 (1 H, td, J 1 1.1, J 2 7.5), 3.89 (3 H, s), 2.16 (1 H, m), 1.18 (4 H, d, J 7.0). Step 2 4-Chloro-2-cyclopropyl-quinoline-3-carboxylic acid ethyl ester [0152] [0153] Phosphorus oxychloride (0.77 ml, 0.082 mols) was added in one portion to a suspension of 2-cyclopropyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester (1.0 g, 0.041 mols) in acetonitrile and the mixture was heated at 75° C. for 90 minutes (becomes a clear solution above 65° C.). The resulting light brown solution was poured into saturated sodium bicarbonate (100 ml); the suspension was extracted with ethyl acetate and the combined organic extracts were dried and concentrated in vacuo to leave 4-Chloro-2-cyclopropyl-quinoline-3-carboxylic acid ethyl ester (1.15 g, 106%) as an off-white solid. R f (AcOEt)=0.73. Step 3 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid [0154] [0155] 4-Chloro-2-cyclopropyl-quinoline-3-carboxylic acid ethyl ester (1.15 g, 0.0041 mols) and 4-hydrazino-benzoic acid (1.0 g, 0.0068 mols) were stirred in ethanol (30 ml) at reflux for 16 h. The bright yellow suspension was diluted with heptane, filtered, washed with cold t-butylmethyl ether and left to dry under suction to yield crude solid containing hydrazine. This solid was suspended in 1 M HCl, filtered, washed with water and then dried in vacuo to yield 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid (1.135 g, 80%) as a yellow solid, LCMS m/z 346.20 [M+H] + @ R T 1.05 min: 96% purity. [0156] δ H (400 MHz, (CD 3 ) 2 SO) 11.4 (1 H, s), 8.43 (2 H, d, J 8.1), 8.21 (1 H, dd, J 1 1.2, J 2 8.1), 8.07 (2 H, d, J 8.1), 7.92 (1 H, d, J 8.1), 7.67 (1 H, t, J 6.6), 7.52 (1 H, t, J 6.5), 3.43 (1 H, m), 1.59 (2 H, m), 1.43 (2 H, m). Step 4 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]-quinolin-2-yl)-benzoyl chloride [0157] [0158] To a suspension of finely ground 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid (0.19 g. 0.55 mmol) in dichloromethane (4 ml) was added oxalyl chloride (1.6 ml, 0.01 mol) followed by a drop of dimethyl formamide. The mixture was stirred under nitrogen at 45° C. for 8 h. The solvent was removed in vacuo to yield 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoyl chloride as a pale yellow solid, LCMS m/z [M+MeOH—Cl] + @ R T 1.46 min: 95% purity. Used without further purification. Step 5 N-(3-Dimethylamino propyl)-4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzamide [0159] [0160] To a partial solution of 4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoyl chloride (0.1 g, 0.28 mmol) in tetrahydrofurane (6 ml) under nitrogen was added a solution of 3-dimethylamino-propyl amine (0.03 g, 0.3 mmol) in tetrahydrofurane (3 ml). The mixture was stirred at R T for 3 h. The solvent was removed under reduced pressure and the yellow solid was washed with a little saturated sodium bicarbonate, water and dried under vacuo to yield N-(3-Dimethylamino propyl)-4-(4-cyclopropyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]-quinolin-2-yl]-benzamide (57 mg, 47%) as a yellow solid. LCMS m/z 430.11 [M+H] + @ R T 0.99 min: 100% purity. Activity *** Preparation of Intermediate 5 4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzoyl chloride [0162] [0163] To a suspension of finely ground 4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzoic acid (1.1 g. 3.4 mmol) in dichloromethane (6 ml) was added oxalyl chloride (2.4 ml, 29 mmol) followed by a drop of dimethyl formamide. The mixture was stirred under nitrogen at 45° C. for 3 h. The solvent was removed in vacuum to yield 4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4, 3-c]quinolin-2-yl]-benzoyl chloride (1.15 g, quantitative) as a pale yellow solid that was used without further purification. EXAMPLE 66 N-(3-Dimethylamino propyl)-4-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzamide hydrochloride [0164] [0165] To a partial solution of 4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzoyl chloride (0.1 g, 0.3 mmol) in tetrahydrofurane (5 ml) under nitrogen was added a solution of 3-dimethylamino-propyl amine (0.03 g, 0.3 mmol) in tetrahydrofurane. The mixture was stirred at rt for 90 minutes. The solvent was removed under reduced pressure and the yellow solid was purified via FCC silica gel (gradient elution, MeOH:H 2 O, Fluka C 18 reverse phase) to yield N-(3-Dimethylamino propyl)-4-(6-fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl]-benzamide hydrochloride (70 mg, 53%) as a yellow solid. [0166] LCMS m/z 408.39 [M+H] + @ R T 0.89 min: 90% purity. Activity *** EXMAPLES 67-141 Were Prepared Analogously From the Appropriate Benzoyl Chloride and the Appropriate Amine [0168] M.S. Example X Z W R R′ (MH+) Activity 67 6-F H H —CH 2 CH 2 CH 2 CH 2 CH 2 — 391.3 ** 68 6-F H H —CH 2 Phenyl H 413.2 *** 69 6-F H H —CH 2 Phenyl Me 427.3 ** 70 6-F H H —CH 2 CH 2 OMe H 381.2 *** 71 6-F H H —CH 2 CH 2 N(Me) 2 H 394.3 *** 72 6-F H H —CH 2 CO 2 Me H 395.3 *** 73 6-F H H —CH 2 CH 2 CH 2 OMe H 395.2 *** 74 6-F H H —CH 2 CH 2 CH 2 N(Me) 2 H 408.3 *** 75 6-F H H H 431.3 ** 76 6-F H H H 419.2 ** 77 6-F H H Et H 351.2 *** 78 6-F H H Et Et 379.3 ** 79 6-F H H H 420.4 *** 80 6-F H H —CH 2 CH 2 CH 2 N(Me) 2 Me 422.4 *** 81 6-F H H —CH 2 CH 2 CH 2 CH 2 N(Me) 2 H 422.4 *** 82 6-F H H H 448.5 *** 83 6-F H H H 434.4 *** 84 6-F H H H 525.3 *** 85 6-F H H —CH 2 CH 2 CH 2 CH 2 CH 2 N(Me) 2 H 450.3 *** 86 H H H —CH 2 CH 2 CH 2 N(Me) 2 H 390.2 *** 87 H H H —CH 2 CH 2 CH 2 CH 2 CH 2 N(Me) 2 H 432.1 ** 88 H H H —CH 2 CH 2 CH 2 CH 2 N(Et) 2 H 432.2 ** 89 H H H —CH 2 CH 2 CH 2 N(Me) 2 Me 404.2 ** 90 6-F H 2—Cl —CH 2 CH 2 CH 2 N(Me) 2 H 442.1 ** 91 H H H H 416.1 ** 92 H H H H 573.0 ** 93 H H H H 445.1 ** 94 H H H H 507.1 ** 95 6-F H H H 591.0 *** 96 H H —CH 2 CH 2 CH 2 N(Me) 2 H 430.1 *** 97 6-F H H H 464.1 *** 98 6-F H H H 463.1 *** 99 6-F H 3—Cl H 482.1 ** 100 6-F H 2—Cl H 497.1 ** 102 6-F H 2—Cl —CH 2 CH 2 CH 2 CH 2 N(Et) 2 H 484.1 ** 103 6-F H 3—Cl —CH 2 CH 2 CH 2 N(Me) 2 H 442.1 ** 104 H H H 470.4 *** 105 6-F H H 516.3 * 106 6-F H H H 470.3 *** 107 6-F H H —CH 2 CH 2 N(iPr) 2 H 451.4 *** 108 6-F H 2—Cl H 496.2 ** 109 6-F H H H 456.1 *** 110 6-F H 2—Cl —CH 2 CH 2 CH 2 CH 2 N(Me) 2 H 456.1 ** 111 6-F H H 406.2 ** 112 6-F H H H 462.1 *** 113 6-F H H H 436.1 *** 114 6-F H H H 434.4 *** 115 6-F H H H 476.1 *** 116 6-F H H H 496.1 *** 117 6-F H H H 436.3 *** 118 6-F H H H 462.3 *** 119 6-F H H H 428.1 ** 120 6-F H H —CH 2 CH 2 SEt H 411.3 *** 121 6-F H H H 448.3 ** 122 6-F H H H 431.3 *** 123 6-F H H H 434.3 ** 124 6-F H H —CH 2 CH 2 CH 2 CH 2 N(Et) 2 H 450.4 *** 125 6-F H H 536.1 *** 126 6-F H H 516.2 *** 127 6-F H H H 428.3 * 128 6-F H H —CH 2 CH 2 CH 2 SMe H 411.3 ** 129 H H H 498.5 *** 130 6-F H H 488.4 *** 131 6-F H H H 446.3 *** 132 6-F H —CH 2 CH 2 CH 2 N(Me) 2 H 448.2 *** 133 6-F H H 502.3 *** 134 6-F H H 486.3 *** 135 6-F H —CH 2 CH 2 CH 2 CH 2 N(Et) 2 H 490.3 *** 136 6-F H H 546.2 ** 137 6-F H H 631.2 *** 138 6-F H H 468.2 ** 139 6-F H H 468.2 * 140 6-F H H 476.2 *** 141 6-F H H 474.3 *** EXAMPLE 142 {3-[4-(6-Fluoro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-ureido}acetic acid ethyl ester [0169] [0170] Ethyl cyanatoacetate (31 mg, 0.24 mmol) was added in one portion to a stirred solution of 2-(4-aminophenyl)-6-fluoro-2,5-dihydropyrazolo[4,3-c]quinolin-3-one (intermediate 2) (50 mg, 0.17 mmol) in N,N-dimethylformamide (2 ml) and the mixture stirred at room temperature for 16 h. Water (1 ml) was then added to the mixture to precipitate a solid, which was filtered, washed with water (1 ml) and then ethyl acetate (1 ml) and finally dried by suction to leave the urea as a yellow solid, LCMS m/z 424.40 [M+H] + @ R T 1.06 min. Activity *** EXAMPLES 143 and 144 [0172] Example 143 LCMS m/z 438.41 [M + H ]+ @ RT 1.13 min. Activity ** Example 144 LCMS m/z 514.46 [M + H ]+ @ RT 1.35 min. Activity * [0173] The following compounds were synthesised by the method of Example 142, substituting the appropriate isocyanate, isothiocyanate or chloroformate for ethyl cyanatoacetate. M.S. Example X Z Y R A (MH +) Activity 144 6-F H O iPr NH 380.3 *** 145 6-F H O nPr NH 380.3 *** 146 6-F H O tBu NH 394.4 *** 147 6-F H O Ph NH 414.3 ** 148 6-F H S NH 394.3 ** 149 6-F H S NH 436.4 * 150 6-F H O tBu O 395.3 *** 151 6-F H O Et O 367.2 ** 152 6-F H O CH 2 CH 2 N(Me) 2 O 410.2 *** 153 H O Me O 375.3 ** 154 6-F H O CH 2 CH 2 CH 2 N(Me) 2 O 424.1 *** 155 6-F H O O 512.3 ** 156 6-F H S nPentyl NH 424.4 ** 157 6-F H S CH(CH 3 )CH(CH 3 )CH 3 NH 424.4 ** 158 6-F H O CH 2 CH 2 CH 2 CH 2 N(Et) 2 NH 465.4 *** 159 H H O nPr NH 362.3 *** 160 H H S NH 376.1 ** 161 6-F H O CH 2 CH 2 CH 2 N(Me) 2 NH 423.3 *** 162 H H O NH 434.5 *** 163 6-F H O CH 2 CH 2 CH 2 CH 2 N(Me) 2 NH 437.2 *** 164 6-F H O NH 463.5 *** Intermediate 6: Preparation of methyl 4-oxothiochromane-3-carboxylate [0174] [0175] Dry tetrahydrofuran (60 ml) was cooled under nitrogen atmosphere to −50 to −60° C. 1M Lithium bis(trimethylsily)amide solution in hexane (56 ml, 56 mmol) was added. The temperature was kept at −50 to −60° C. and thiochroman-4-one was added dropwise over 20 min. Stirring was continued at low temperature for 60 min. Methyl cyanoformate (4.84 ml, 60.9 mmol) was added dropwise over 5 min to the reaction mixture. The obtained suspension was stirred at −50 to −60° C. for 80 min and then allowed to warm up to room temperature. Saturated ammonium chloride solution (100 ml) was added. The phases were separated, the aqueous phase extracted with ethyl acetate (2×100 ml). The combined organic phases were washed with water (50 ml), dried over magnesium sulphate, filtered and concentrated under vacuum. An orange oil was obtained and purified by column chromatography. The title compound was isolated as a yellow solid (4.70 g, 21.1 mmol, 42%). LCMS: m/z 221 [M−H] + . Intermediate 7: Preparation of 4-(3-Oxo-3a,4-dihydro-3H-thiochromeno[4,3-c]pyrazol-2-yl)-benzoic acid [0176] [0177] 4-Oxothiochromane-3-carboxylate (0.50 g, 2.25 mmol) and hydrazinobenzoic acid (0.377 g, 2.48 mmol) were mixed in acetic acid (6 ml). The mixture was heated to reflux for 30 min. Excess acetic acid was distilled off to give a brown oil. Diethylether was added, a precipitate formed which was collected by filtration and dried under vacuum. The crude product was isolated as a red/brown solid (797 mg). LCMS: m/z 325 [M+H] + . No purification was carried out. Intermediate 8: Preparation of 4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzoic acid [0178] [0179] Crude 4-(3-Oxo-3a,4-dihydro-3H-thiochromeno[4,3-c]pyrazol-2-yl)-benzoic acid (250 mg, 0.77 mmol) was dissolved in dimethyl sulphoxide (6 ml). O-Chloranil (189 mg, 0.77 mmol) was added and the mixture was stirred at room temperature overnight. Water (20 ml) was added and the solids were collected by filtration and washed with water. The filter cake was triturated with toluene, filtered and dried under vacuum. The title compound was isolated as a dark brown solid (230 mg, 0.71 mmol, 92%). LCMS: m/z 323 [M+H] + [0180] Alternatively crude 4-(3-Oxo-3a,4-dihydro-3H-thiochromeno[4,3-c]pyrazol-2-yl)-benzoic acid can be stirred in dimethyl sulphoxide under exposure to air. It was found that air oxidation provides clean product, however the reaction is much slower. EXAMPLE 165 Preparation of N-[3-(dimethylamino)propyl]-4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0181] [0182] 4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzoic acid (55 mg, 0.17 mmol) was suspended in anhydrous dimethyl acetamide (1 ml). Diisopropyl-ethyl amine (46.5 mg, 0.36 mmol, 62μl) was added followed by 3-dimethylaminopropylamine (17.5 mg, 0.17 mmol) and [(benzotriazol-1-yloxy)-dimethylamino-methylene]-dimethyl-ammonium hexafluoro phosphate (65 mg, 0.17 mmol). The mixture was stirred at room temperature for 4 h and was purified by preparative HPLC. The title compound was isolated as a brown solid. LCMS: m/z 407 [M+H] + Activity ** EXAMPLE 166 Preparation of N-[(cyclohexylamino)propyl]-4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0184] [0185] The reaction was carried out as described above. LCMS: m/z 461 [M+H] + Activity *** EXAMPLE 167 Preparation of N-(pyrrolidin-1-yl-butyl)-4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0187] [0188] The reaction was carried out as described above. LCMS: m/z 447 [M+H] + Activity * EXAMPLE 168 Preparation of 4-(3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)-N-1,2,2,6,6-pentamethylpiperidin-4-ylbenzamide [0190] [0191] The reaction was carried out as described above. LCMS: m/z 475 [M+H] + Activity ** Intermediate 9: Preparation of 3-[(2-fluorophenyl)sulfanyl]propanoic acid [0193] [0194] 2-Fluorothiophenol (5.0 g, 39 mmol) was dissolved in tetrahydrofuran (50 ml) under a nitrogen atmosphere. Triethylamine (3.94 g, 5.33 ml, 85.8 mmol) was added. Acrylic acid (2.81 g, 2.67 ml, 39 mmol) was dissolved in tetrahydrofuran and added dropwise to the reaction solution over 2 h at room temperature. The mixture was stirred at room temperature overnight. 1M Hydrochloric acid (50 ml) was added and the phases were separated. The aqueous phase was washed with ethyl acetate (2×50 ml). The combined organic phases were dried over magnesium sulphate, filtered and concentrated under vacuum. A yellow oil was obtained which solidified upon storage at room temperature. The solid was triturated with hexane, filtered and dried under vacuum. The title compound was isolated as an off-white solid (4.19 g, 20.9 mmol, 54%). Intermediate 10: Preparation of 8-fluoro-2,3-dihydro-4H-thiochromen-4-one [0195] [0196] 3-[(2-Fluorophenyl)sulfanyl]propanoic acid (4.0 g, 20 mmol) was mixed with concentrated sulphuric acid (20 ml) at 0-5° C. The reaction solution was stirred at 0 to 5° C. for 3 h then allowed to warm up to room temperature overnight. The mixture was quenched dropwise into ice to give a white suspension. The aqueous phase was extracted with ethyl acetate (1×200 ml, 1×100 ml). The combined organic phases were washed with saturated sodium bicarbonate solution (1×50 ml), water (1×50 ml), 1M hydrochloric acid (50 ml) and water (2×50 ml). The organic phase was dried over magnesium sulphate, filtered and concentrated under vacuum. The title compound was isolated as a yellow solid (2.10 g, 11.5 mmol, 58%). Intermediate 11: Preparation of methyl 8-fluoro-4-oxothiochromane-3-carboxylate [0197] [0198] 1M Lithium hexamethyldisilazide solution in hexane (13.2 ml) was dissolved in anhydrous tetrahydrofuran (20 ml) under nitrogen atmosphere. The solution was cooled to −78° C. 8-Fluoro-2,3-dihydro-4H-thiochromen-4-one (2.00 g, 11 mmol) was dissolved in tetrahydrofuran (40 ml), the solution was transferred to the dropping funnel and added dropwise over 30 min to the reaction mixture maintaining the temperature below −60° C. An orange clear solution was obtained which was stirred at −78° C. to −65° C. for 2 h. Methyl cyanoformate (0.935 g, 0.87 ml) was dissolved in tetrahydrofuran (2 ml) and added dropwise to the reaction solution. Stirring was continued at low temperature for 1 h, the mixture was then allowed to warm to room temperature. Saturated ammonium chloride solution (20 ml) and water (10 ml) were added, the phases mixed for 5 min and separated. The aqueous phase was washed with ethyl acetate (2×100 ml) and the combined organic phases were dried over magnesium sulphate. The mixture was filtered and the solvent removed under vacuum to give an orange oil. The crude oil was purified by column chromatography; mobile phase: hexanes, gradient to hexanes/ethyl acetate [90:10]. The title compound was isolated as a yellow solid (1.19 g, 4.95 mmol, 45%). Intermediate 12: Preparation of 4-(6-fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzoic acid [0199] [0200] Methyl 8-fluoro-4-oxothiochromane-3-carboxylate (1.19 g, 4.95 mmol) and 4-hydrazinobenzoic acid (755 mg, 4.95 mmol) were mixed with glacial acetic acid (10 ml). The mixture was heated to reflux for 4 h. Excess acetic acid was removed under vacuum to give an orange oil. Ethyl acetate (10 ml) was added and the mixture sonicated. Precipitation of an orange solid was observed. The solids were collected by filtration and washed with ethyl acetate. The filter cake was taken up in dimethyl suphoxide (10 ml) and air-oxidised at room temperature for one week. Water (20 ml) was added to the reaction mixture, the solids were collected by filtration, slurried in ethyl acetate, filtered and dried under vacuum. The title compound was isolated as an orange powder (175 mg, 0.51 mmol, 10%). LCMS: m/z 341. EXAMPLE 169 Preparation of N-[3-(dimethylamino)propyl]-4-(6-fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0201] [0202] 4-(6-Fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzoic acid (41 mg, 0.12 mmol) was dissolved in anhydrous dimethyl-acetamide(1 ml). Diisopropyl-ethyl amine (46 mg, 0.36 mmol, 62 μl) was added followed by [(benzotriazol-1-yloxy)-dimethylamino-methylene]-dimethyl-ammonium hexafluoro phosphate (65 mg, 0.17 mmol) and 3-dimethylaminopropylamine (12 mg, 0.12 mmol). The mixture was stirred at room temperature overnight and purified by preparative HPLC. The title compound was isolated as a brown solid. LCMS: m/z 425 [M+H] +. Activity ** EXAMPLE 170 Preparation of N-[(cyclohexylamino)propyl]-4-(6-fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0204] [0205] The reaction was carried out as described above. LCMS: m/z 479 [M+H] + . Activity ** EXAMPLE 171 Preparation of N-(pyrrolidin-1-yl-butyl)-4-(6-fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)benzamide [0207] [0208] The reaction was carried out as described above. LCMS: m/z 465 [M+H] + . Activity *** EXAMPLE 173 Preparation of 4-(6-fluoro-3-oxothiochromeno[4,3-c]pyrazol-2(3H)-yl)-N-1,2,2,6,6-pentamethylpiperidin-4-ylbenzamide [0210] [0211] The reaction was carried out as described above. LCMS: m/z 493 [M+H] + Activity *** Assay Section [0213] The examples described above were tested in a cell free Homogenous Time Resolved Fluorescence (HTRF) assay to determine their activity as inhibitors of the CD80-CD28 interaction. [0214] In the assay, europium and allophycocyanin (APC) are associated with CD28 and CD80 indirectly (through antibody linkers) to form a complex, which brings the europium and APC into close proximity to generate a signal. The complex comprises the following six proteins: fluorescent label 1, linker antibody 1, CD28 fusion protein, CD80 fusion protein, linker antibody 2, and fluorescent label 2. The table below describes these reagents in greater detail. Fluorescent Anti-Rabbit IgG labelled with Europium label 1 (1 μg/ml) Linker Rabbit IgG specific for mouse Fc antibody 1 fragment (3 μg/ml) CD28 fusion CD28 - mouse Fc fragment fusion protein protein (0.48 μg/ml) CD80 fusion CD80 mouse Fab fragment (C215) fusion protein protein (1.9 μg/ml) Linker GαMκ-biotin: biotinylated goat IgG antibody 2 specific for mouse kappa chain (2 μg/ml) Fluorescent SA-APC: streptavidin labelled label 2 allophycocyanin (8 μg/ml) [0215] On formation of the complex, europium and APC are brought into proximity and a signal is generated. [0216] Non-specific interaction was measured by substituting a mouse Fab fragment (C215) for the CD80 mouse Fab fragment fusion protein (1.9 μg/ml). The assay was carried out in black 384 well plates in a final volume of 30μl. Assay buffer: 50 mM Tris-HCl, 150 mM NaCl pH 7.8, containing 0.1% BSA (w/v) added just prior to use. [0217] Compounds were added to the above reagents in a concentration series ranging between 100 μM-1.7 nM. The reaction was incubated for 4 hours at room temperature. Dual measurements were made using a Wallac Victor 1420 Multilabel Counter. First measurement: excitation 340 nm, emission 665 nm, delay 50 μs, window time 200 μs. second measurement: excitation 340 nm, emission 615 nm, delay 50 μs, window time 200 μs. Counts were automatically corrected for fluorescence crossover, quenching and background. [0218] By way of illustration, the EC 50 results for the compounds of Examples 15, 21, 29, 35 and 83 were 8 μM, 1.9 μM, 950 nM, 148 nM and 90 nM respectively. For convenience, the EC50 activities of compounds tested are recorded above in summary form as: EC50: *=>10 μM, **=1-10 μM, ***=<1 μM.

The present invention relates to novel heterocyclic compounds, to methods for their preparation, to compositions containing them, and to methods and use for clinical treatment of medical conditions which may benefit from immunomodulation, including rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis. More particularly the present invention relates to novel heterocyclic compounds, which are CD80 antagonists capable of inhibiting the interactions between CD80 and CD28.

FIELD OF THE INVENTION [0001] The invention relates to fluid connections, in particular the fluid connection devices for connecting a fluid pipe to another pipe or to a container, in the field of biopharmaceutical applications. BACKGROUND OF THE INVENTION [0002] Specifically, the tubes or pipes used in the biopharmaceutical field are flexible or highly flexible pipes which are used to convey various biopharmaceutical substances, most often with the necessary aseptic precautions. [0003] Fluid connection devices commonly comprise a first male connector (in other words forming a male interface) able to be received in a second complementary connector forming a female interface, which is a simple and well-understood solution. However, a male connector cannot be connected to another male connector, nor can a female connector be connected to another female connector. [0004] In the context of assembling a flexible pipe to another pipe or container by means of a fluid connection, there is a need to improve the interoperability of the connectors in order to facilitate the construction of modular biopharmaceutical assemblies. [0005] There are known fluidic connections for connecting together two “genderless” connectors that are functionally equivalent in terms of coupling. However, the known genderless fluid connectors generally require an axial insertion movement followed by a rotational movement about the axis. [0006] In addition, the sterile or aseptic precautions for such applications necessitate good verification of the fluid connections established between the various entities in a biopharmaceutical assembly such as pipes, bags, filters, etc. [0007] We therefore seek ways to check the coupling position in a simple and reliable manner, meaning to verify that the coupling movement has reached the correct final position, possibly being secured in this position by locking means. [0008] For genderless connectors with axial translational movement followed by rotation, proper completion of the rotation is difficult to verify. [0009] There is therefore a first need to provide a connection device for connecting together two genderless connectors with a coupling movement that only involves axial translational movement. [0010] In biopharmaceutical applications, the flexible pipes allow the circulation, passage, and communication of a fluid, such as a biopharmaceutical fluid, and can either be connected to a similar flexible pipe or to a vessel or container which may be rigid or flexible. [0011] The vessel or container in question may, in the current case, be a container for storing and/or processing content such as a biopharmaceutical product. In the current case, such a container is understood to mean a rigid or semi-rigid reusable container or a flexible disposable container such as a bag or even a filter cartridge. [0012] This bag may be one of the substantially thin “2D” bags, such as those marketed by Sartorius Stedim Biotech under the brand Flexboy®, having a typical volume of between 50 ml and 50 liters. This flexible bag may also be a “3D” bag, such as those marketed by Sartorius Stedim Biotech under the brand Flexel®, having a larger volume and a substantial size in all three dimensions. Note that a pipe such as the pipe to which the invention applies can be placed between two bags or a larger number of bags. [0013] A pipe such as that to which the invention is applied, usually of circular cross-section, is typically made of a plastic such as silicone, thermoplastic elastomers (TPE), or PVC, this list being non-limiting. It has a certain general stability and simultaneously both a certain overall flexibility and a certain local flexibility, allowing, when sufficient force is applied, crimping the pipe or substantially deforming it radially. [0014] In a typical embodiment, for example, the pipe has an outer diameter between 8 mm and 30 mm for example, with the thickness depending on the material, the diameter, and the applications. [0015] In the prior art, to couple such a flexible pipe, it is slipped over a tubular nozzle, whereupon a pipe clamp is placed around the pipe and then the clamp is tightened. The tightened clamp thus exerts a radial inward pressure to maintain the hose on the nozzle, on the one hand to ensure a good seal against the nozzle and on the other hand to prevent the pipe from detaching from the nozzle when pulled. [0016] For such pipe clamps, a plastic clamp can be used for example, of polyamide for example such as Rilsan®. This type of plastic clamp, also sometimes called Serflex®, comprises a system of notches on a strip cooperating with a locking hook arranged in the head, such that the tightening is irreversible. In other words, once the strip is engaged in the head to form a loop, the strip is pulled to reduce the diameter of the loop and tighten the clamp; all return movement is prevented by the engagement of the hook in one of the strip notches. After tightening, to prevent the strip from projecting too far beyond the diameter of the clamp loop, the free portion of the strip is cut off near the head of the clamp. The undetached remaining portion of the strip often has a sharp edge which can cut. [0017] As an alternative to the plastic clamp, a metal clamp can be used which is in the form of a preformed ring having one or two “ears” projecting outward with respect to the general shape of the ring of the clamp, this type of clamp sometimes being called an Oetiker® clamp. After insertion of the clamp onto the pipe to be retained, a tool is used to crimp the ear (or ears) of the clamp which causes permanent deformation and thus a narrowing of the major diameter of the ring and as a result tightens the clamp on the pipe. This type of clamping with a metal ring is particularly robust and reliable. However, at the point where the ear was crimped by the tool, there may be a burr or roughness which forms a sharp edge that can be damaging. [0018] Whether plastic or metal, once such clamps are installed in biopharmaceutical assemblies, these assemblies may need to be transported or moved and therefore there is a risk of damage by the damaging parts of these clamps to other elements of the biopharmaceutical assembly, particularly the flexible bags or flexible pipes, which can cause a leakage or loss of sterilization that is detrimental to the biopharmaceutical application. [0019] In addition, these clamps are easy to access (and thus can be removed) and does not guarantee a satisfactory image or aesthetics. [0020] There is therefore a second need to prevent the pipe clamp from posing a danger to the surrounding elements. OBJECTS AND SUMMARY OF THE INVENTION [0021] Below is provided a description of the invention as characterized in the claims, offering an improvement intended to overcome, at least in part, one of the aforementioned disadvantages of the known prior art. [0022] According to a first aspect, the invention relates to a fluid connection device adapted and intended for connecting a first wall forming a first flexible pipe defining a first fluid space, to a second wall defining a second fluid space in the form of a second flexible pipe or flexible enclosure that is semi-rigid or rigid and disposable, in a biopharmaceutical assembly, comprising: a first connector defining a first hollow passage, adapted and intended for connection to the first fluid space, a second connector, similar to the first connector, defining a second hollow passage, adapted and intended for connection to the second fluid space, the first connector and the second connector being adapted and intended to be coupled together in a genderless manner, by an insertion movement that is essentially an axial translation along the axis A, into a relative coupling position, which defines a mating plane P perpendicular to the main axis, each of the first and second connectors comprising, in an alternating manner along the circumferential direction, N flexible snap-fitting tabs and N stop surfaces, N being a strictly positive integer, the flexible snap-fitting tabs projecting axially forwards relative to the mating plane, and the stop surfaces being set back from the mating plane so that, in the coupling position, the snap-fitting tabs of one of the connectors clip into place beyond the stop surfaces of the other connector, such that the resulting position is locked by the snap-fitting tabs. [0025] In this manner, a fluid connection device is proposed that is based on genderless connectors, which facilitates interoperability, modularity, and the formation of modular biopharmaceutical assemblies, because all the genderless connectors so formed can be connected to any another connector of the same genderless type, with no need to worry about the gender of each connector to be connected. In addition, there is no need to perform a rotational operation on the connection after the axial translational movement, which facilitates visual verification of the correct coupling position. [0026] Advantageously, the snap-fitting tabs of one of the two connectors are formed integrally from the body of this connector, and each of the snap-fitting tabs move into the coupling position through a slot formed in a collar of the other connector. A collar is therefore provided which facilitates gripping and manually connecting the device, compatible with the compact arrangement of the clip-on means, in a genderless connector. [0027] Advantageously, the snap-fitting tabs move apart outwardly during the coupling movement and return towards their rest position at the end of the coupling movement where they bear on the stop surfaces; in this manner the operator establishing the coupling has visual and/or auditory and/or haptic feedback on the proper coupling of the connectors. [0028] Advantageously, each connector comprises a substantially cylindrical body, and in the coupling position the snap-fitting tabs lie adjacent to the body of the opposite connector and external thereto, and are resiliently biased radially inward if someone attempts to move them away from their rest position, such that they must all be moved apart simultaneously to unlock the connection. In this manner, the radial footprint of the locking device for this type of genderless connectors is quite optimized, and in addition the locking is particularly robust. [0029] In one embodiment, each snap-fitting tab has a stirrup shape. This provides the snap-fitting tabs with satisfactory mechanical strength. [0030] In one embodiment, the device may further comprise a protective cover formed by two half portions configured to close together in the radial direction to at least partially surround the first connector and the second connector, the cover serving as an indicator of proper coupling when snap-fitted into its closed position. In this manner, correct positioning of the protective cover is used to indicate proper coupling of the first and second connectors. [0031] In one embodiment, the protective cover comprises two generally semi-cylindrical complementary portions connected by a flexible hinge portion, and the two portions are adapted to be snap-fitted together in an area diametrically opposite the hinge area, such that the protective cover is easily installed around the first and second connectors, in particular around their respective joined collars. Moreover, the protective cover may advantageously be molded as a single piece of synthetic material. [0032] In one embodiment, the cover comprises an annular inner groove adapted to form, in the coupling position, a lock that immobilizes the adjacent collars that are respectively part of the first and second connectors. In this manner, the correct position of the protective cover reliably indicates that the first and second connectors are coupled and locked. [0033] In one embodiment, the annular inner groove provides at least one tapered portion (having a trapezoidal cross-section) so as to exert axial pressure on the collars, which urges the two connectors closer together. The action of clipping the protective cover closed helps complete, if necessary, the movement of coupling the first and second connectors together. [0034] In one embodiment, in the coupling position, the two connectors are arranged symmetrically relative to the mating plane, furthermore with an angular displacement of 360°/2N. This allows providing a simple genderless interface with several possible angular coupling positions, N possible angular positions in the current case. [0035] In one embodiment, the number N is between 1 and 10, preferably equal to 4; whereby the number of possible angular positions for the coupling facilitates completion of the coupling. [0036] In one embodiment, each connector further comprises a seal arranged radially inward within the cylindrical body, pressure being applied to the two seals in the axial direction when the two connectors are snap-fitted into position. This is a well-understood and standard solution for the sealing function of genderless connectors. [0037] In one embodiment, each connector further comprises a temporary aseptic sealing membrane arranged on the front face of each of the seals, intended to be removed after coupling the connectors so that the two fluid spaces are placed in communication without any communication with the surrounding air; modular biopharmaceutical assemblies can thus be created under conditions of sterility or protection from the ambient air. [0038] In one embodiment, the closing of the cover causes, after removal of the sealing membranes, additional travel in the coupling which increases the axial pressure between the seals; whereby the pressure on the seals is increased and the quality of the seal is improved. [0039] In one embodiment, the connection device may further comprise a pipe clamp adapted and intended to be arranged around the end of the first pipe in order to clamp said pipe onto a tubular nozzle of the first connector, and the protective cover comprises at least one tubular extension adapted to be positioned, when the cover is clipped into the snap-fitted position, at least partially facing the pipe clamp in the radial direction, whereby the tubular extension prevents the pipe clamp from coming into direct contact with external elements. In this manner, the pipe clamp cannot come into direct contact with external elements, and this prevents possible damage to adjacent flexible bags or pipes by a damaging portion of the pipe clamp. [0040] In one embodiment, the pipe clamp is a metal clamp having a general ring shape with at least one “ear”, said ear being intended to be crimped to tighten the clamp, and the tubular extension is at a distance from the outer surface of the pipe. The crimped ear solution is a standard and well-understood solution for the pipe clamp function. In addition, several different diameters of flexible pipe and tubular nozzle are compatible with a single definition of the tubular extension of the protective cover. [0041] In one embodiment, one of the connectors or the protective cover may further comprise an identifier such as a barcode or RFID tag or color code. In this manner, it is easy to access information concerning the flexible bag and/or the biopharmaceutical product contained therein, and traceability is facilitated. [0042] In one embodiment, the snap-fitting tabs of the connectors each comprise a longitudinal extension which projects forward, so as to provide a gripping area for spreading apart the snap-fitting tabs in order to unlock the coupling position; this provides a solution for releasing the coupling of the first and second connectors. [0043] In one embodiment, the device may further comprise a pipe clamp adapted and intended to be arranged around the end of the pipe in order to clamp said pipe onto a tubular nozzle of the first connector, and the snap-fitting tabs of the second connector each comprise a longitudinal extension which projects forward so as to cover, in the coupling position, the pipe clamp in the radial direction; whereby the extensions prevent the clamp from damaging nearby external elements, being without the addition of a cover as a separate part. [0044] According to a second aspect, the invention relates to a genderless connector for fluid connection, adapted and intended for coupling to another similar genderless connector, in a fluid connection device as described above, [0000] the connector comprising, in an alternating manner along the circumference, N flexible snap-fitting tabs and N stop surfaces where N is a strictly positive integer, the flexible snap-fitting tabs projecting axially forward relative to the mating plane and the stop surfaces being set back from the mating plane such that, in the coupling position, the snap-fitting tabs of one of the genderless connectors clip onto the stop surfaces of the other similar genderless connector so that the resulting position is locked by the snap-fitting tabs, the mutual coupling being achieved in a substantially axial translational movement along axis A. [0045] According to a third aspect, the invention relates to a biopharmaceutical assembly comprising a fluid connection device as described above. [0046] According to a fourth aspect, the invention also concerns a method for forming a connection device as described above, the method comprising the steps of: [0000] /a/ providing a first connector and a second connector, both with a compatible genderless interface, and each equipped with a collar and a seal with aseptic membrane closing off the opening defined by the seal, /b/ establishing a primary coupling of the first and second connectors, /c/ removing the aseptic sealing membranes, /d/ inserting a protective cover comprising an annular inner groove having a cross-section comprising two tapered shapes, the closing of the cover causing additional axial travel in the coupling to increase the contact pressure between the two seals. [0047] In a fifth aspect, the invention also concerns a kit of parts comprising the first and second genderless connectors described above, optionally with a protective cover and optionally with at least one pipe clamp and a flexible pipe. In addition, the invention concerns the assembly of the above parts into an assembled state, optionally with the pipe clamp protected by the protective cover, or longitudinal extensions of the snap-fitting tabs. BRIEF DESCRIPTION OF THE DRAWINGS [0048] The figures of the drawings will now be briefly described. [0049] FIG. 1 is an exploded view of the connection device according to the invention. [0050] FIG. 2 is an axial sectional view of the connection device of FIG. 1 , in the coupled position, along section line II-II shown in FIG. 3 . [0051] FIG. 3 is a cross-sectional detailed view of the connection device of FIG. 1 , in the coupled position, along section line shown in FIG. 2 . [0052] FIG. 4 is a perspective view of the connection device of FIG. 1 in the assembled position, shown without a protective cover. [0053] FIG. 5 represents another embodiment, in an axial sectional view, where the second connector comprises a base fixed to a biopharmaceutical enclosure. [0054] FIG. 6 illustrates an alternative embodiment wherein the snap-fitting tabs comprise an axial extension of extra length. [0055] FIGS. 7A-7C represent an alternative embodiment, with temporary aseptic sealing membranes enabling the connection of connectors without exposure to the open air. [0056] Below is a detailed description of several embodiments of the invention, accompanied by examples and with reference to the drawings. DETAILED DESCRIPTION OF THE INVENTION [0057] In the example illustrated in FIGS. 1 to 4 , a first flexible pipe 11 is connected to a second flexible pipe 11 ′ in a biopharmaceutical assembly, by means of a fluid connection device 10 which comprises a first genderless connector 1 and a second genderless connector 1 ′ which can be coupled. [0058] The first flexible pipe 11 can be generally defined as a first wall 11 defining a first fluid space 71 . Similarly, the second flexible pipe 11 ′ can be generally defined as a second wall 11 ′ defining a second fluid space 72 . [0059] The first connector 1 is made of synthetic material, more specifically it can be obtained by molding a plastic material, for example polypropylene, polyethylene, polycarbonate, polysulfone. [0060] The first connector 1 comprises a tubular nozzle 9 at one end 1 a , and a coupling interface with the second connector at the other end. The tubular nozzle 9 is symmetrical about the axis A. The coupling interface is a genderless interface that is intended to be inserted into an identical or similar interface that is also genderless. There is thus no male or female entity in such a genderless connection. [0061] The first connector further comprises an intermediate portion which is in the form of a cylindrical body 18 centered on the axis A. A collar 16 extends radially outward from the cylindrical body 18 . In this collar are formed a plurality of slots 17 evenly distributed around the circumference of the cylindrical body 18 . In the illustrated example, there are four slots, each in the form of an arc of about 45°, these arcs allowing the passage of an element through the collar in an axial direction as will be seen below. [0062] Inside the cylindrical body 18 there is a compressible seal 13 ; this seal is in the form of a ring centered on A and having a generally rectangular cross-section in the example illustrated. It comprises in particular a bearing face 13 a intended to cooperate with another bearing face that is part of the seal of another opposing connector to which the first connector can be coupled. The seal 13 is preferably made of elastomeric material or silicone. [0063] The front face 16 a of the collar 16 , in other words the face which is opposite the position of the tubular nozzle, and near or adjacent to a mating plane P, said mating plane defining a reference position for the mating of the bearing faces 13 a of the seals of the two connectors in the coupled position. [0064] Projecting beyond the mating plane, opposite the position of the tubular nozzle, are snap-fitting tabs 6 which in the illustrated example are in the form of a stirrup having a square cross-section. The snap-fitting tab has two longitudinal portions 6 b extending from the collar, parallel to the axis A, and a transverse arcuate portion 6 a connecting the ends of the two longitudinal portions 6 b. [0065] In the example illustrated, there are four snap-fitting tabs 6 which alternate with slots 17 , previously described, and occupying the same diameter length as the slots 17 previously described, each snap-fitting tab defining an arc of approximately 45°. [0066] Each snap-fitting tab 6 is intended to pass through the corresponding slot of the opposing connector, knowing that to couple a first connector to a second similar or identical connector 1 ′, these must exhibit an angular offset so that the snap-fitting tab of the first is facing a slot of the second and vice versa (see FIGS. 1 and 4 ). [0067] In addition, provided on the cylindrical body 18 of the connector, and set back relative to the mating plane and the collar, are stop surfaces 8 which may be provided as shoulders, said stop surfaces each being configured to cooperate with a transverse arm 6 a of a snap-fitting tab, in the coupling position, thereby obtaining a clip-on effect, in other works locking the coupled position, as is apparent in FIG. 4 . [0068] One will note that the snap-fitting tabs 6 are adjacent to the cylindrical body 18 of the opposing connector 6 ; the snap-fitting tabs 6 are arranged outside the cylindrical body 18 of the opposing connector, and substantially mate with the outer contours of the cylindrical body. [0069] Each stop surface 8 may be formed in a projection of the cylindrical body, comprising a slight anterior ramp to move apart the snap-fitting tabs during insertion of the connector and a posterior radial surface forming the stop surface 8 against which the transverse portion 6 a of the snap-fitting tab comes to bear. [0070] In FIG. 4 , in the coupling position, the collars 16 , 16 ′ are more or less adjacent to one another when the transverse portion 6 a of the tabs abuts against the stop surfaces 8 under the reactive effect of the seal. It will be seen below that the space between the collars in the coupling position, which can be more or less significant, can be reduced to increase pressure between the seals. [0071] Note that the snap-fitting tabs 6 are spread apart radially outward during the coupling movement so that each transverse portion 6 a travels beyond the facing stop surface 8 , which forms in the illustrated example a ramp for this purpose. [0072] The second connector 1 ′, to which the first connector can be coupled, is strictly identical to the first connector in form and material in the example illustrated in FIGS. 1 to 4 . In particular, it comprises a tubular nozzle 9 ′ to which the second flexible pipe 11 ′ can be attached, a cylindrical body 18 with a collar 16 ′, a seal 13 ′, snap-fitting tabs 6 , slots 17 A, and stop surfaces 8 , all of which are identical to those already described for the first connector. [0073] However, the second connector may present more or less substantial differences provided that the coupling interface with the first connector remains compatible, in particular the position of the transverse arms of the snap-fitting tabs and the position of the stop surfaces, and to a lesser extent the passage provided by the slots. [0074] In particular, the two connectors may be of different colors, which facilitates visual verification of proper coupling. [0075] The tubular nozzle 9 comprises an annular bead 19 , which in the illustrated example has a slight ramp 19 a on the side of the flexible pipe 11 to be inserted and a shoulder 19 b on the opposite side. The tubular nozzle may comprise a greater number of beads, for example successive catches as are known per se. [0076] One will note that the inside diameter D 1 of the tubular nozzle 9 is substantially similar to the inside diameter of the flexible pipe 11 at rest. [0077] When the flexible pipe 11 is slid onto the tubular nozzle 9 , the pipe is deformed radially outward by the shape of the ramp 19 a , then as the insertion proceeds it returns to a narrower diameter 9 a at the cylindrical bearing surface 9 a. [0078] The insertion can continue until the front end 11 a of the pipe comes to bear against the rear part 18 b of the cylindrical body 18 (see FIGS. 2 and 4 ). [0079] Once the flexible pipe is inserted onto the tubular nozzle 9 , a pipe clamp 3 is placed around the pipe at the abovementioned bearing surface 9 a . It should be noted here that the pipe clamp 3 may be placed on standby around a rear portion of the pipe beforehand, prior to the insertion process. Once the clamp is in an appropriate position relative to the bearing surface of the tubular nozzle, the clamp is tightened. [0080] The pipe clamp shown in the figures is a metal clamp with only one ear 31 provided for tightening. There could be more than one ear, however. [0081] Pliers are used, for example, to flatten the ear shape 31 so as to reduce the diameter of the ring 30 formed by the pipe clamp 3 . As a result, the pipe clamp then has a smaller diameter than that of the outer surface of the flexible pipe at rest, and therefore exerts a radial force directed inward. [0082] This radial pressure has two objectives: the first is to ensure a sufficiently effective seal between the pipe 11 and the tubular nozzle 9 , and the second is to mechanically retain the pipe around the nozzle to prevent the pipe from detaching from the tubular nozzle when pulled, due to the aforementioned shoulder 19 b. [0083] In addition, an optional protective cover 5 is advantageously provided which at least partially covers the first and second collars 16 , 16 ′ that are part of the first and second connectors 1 , 1 ′ respectively, as is apparent in FIG. 2 . [0084] The protective cover 5 is formed by two parts 5 a , 5 b forming two half-portions of similar size joined by a flexible hinge portion 50 , all obtained in a single molding operation. Specifically, each part may be in the form of a semi-cylindrical portion with a protruding ring 56 in the central area, although other shapes are possible. The two portions are intended to be clipped together in an area diametrically opposite the hinge area, for example by means of hooks 58 , 59 that clip together, which are simply and symbolically represented in FIG. 1 . [0085] Once the protective cover is installed around the collars of the first and second connectors 1 , 1 ′, the cover 5 thus forms an indicator of proper coupling of the connectors: if the collars 16 , 16 ′ are too far apart, the protective cover cannot be closed around them. [0086] Advantageously, the cover comprises an annular inner groove 55 adapted to form, in the coupling position, a lock that immobilizes the adjacent collars 16 , 16 ′ against one another as is apparent in FIG. 2 . [0087] In addition, the inner groove may comprise at least one tapering portion 53 , 54 (of trapezoidal cross-section) so as to exert axial pressure on the collars, which urges the two connectors closer together and increases the mutual contact pressure between the seals 13 , 13 ′. [0088] In addition, to facilitate the movement of closing the two half-portions of the cover on the collars, the radially external rear portion of the collars 16 b may comprise a chamfer 16 b which facilitates sliding along the tapering portions 53 , 54 . [0089] In addition, the protective cover 5 may be such that it forms protective elements for the first pipe clamp 3 on the first connector 1 and/or for the pipe clamp 3 ′ of the second connector 1 ′. [0090] More specifically, the protective cover comprises a first axial extension 51 in the first connector direction and a second axial extension 52 in the second connector direction. In the example shown, the protective cover is thus symmetrical relative to the mating plane P of the coupling. Its installation can therefore be oriented in one direction or the opposite direction. [0091] The first axial extension 51 forms such “protective elements” for the first pipe clamp 3 : in effect the pipe clamp, in the coupling position, is positioned within the inner region defined by this axial extension 51 . In this manner, if during handling or movement of the connection device, the device comes into contact with external elements 90 , then it is not the pipe clamp which will be in contact with said external elements 90 but instead it will be the protective cover 5 , here the axial extension 51 , which will come into contact with the external element(s) 90 (see FIG. 2 ). Thus, damage from contact with a potentially damaging portion of the clamp 3 can be advantageously avoided. [0092] The same arrangements and advantages are obtained, mutatis mutandis, for the second connector and its pipe clamp 3 ″. [0093] It should be noted that the axial extensions may have different shapes: they may be a plurality of separate tabs distributed around the circumference, or a plurality of separate cylindrical wall portions distributed around the circumference. [0094] Note that the first connector 1 defines a first hollow passage intended to be placed in fluid communication with the first space 71 . Similarly, the second connector defines a second hollow passage intended to be placed in fluid communication with the second space 72 (the inside of the second pipe in the example shown). [0095] In another embodiment shown in FIG. 5 , the second connector 2 is not intended to receive a flexible pipe, but rather to be secured to a container 12 intended to hold biopharmaceutical fluid. The container can be generally defined as a flexible enclosure 12 formed by a second wall defining a second fluid space 72 . [0096] A wide disc 28 equipped with a central hole is fixed by welding 29 to the wall 12 of the flexible enclosure. A tubular portion 20 extends from the wide disc 28 to the cylindrical body 18 comprising the stop surfaces 8 , collar 16 ′, and seal 13 ′. [0097] In this embodiment, there is no second pipe clamp, and furthermore the axial length of the second connector 2 is shorter than the axial length of the first connector 1 . As a result, the protective cover 5 suitable for this application is asymmetrical relative to the mating plane P, the second tubular extension 52 being shorter than the first tubular extension 51 . However, the shape of the annular inner groove 55 is quite similar to what has been described above, as are the protection means for the pipe clamp 3 . [0098] Note that FIG. 5 illustrates that it is possible to provide several different diameters of nozzles 9 , 9 ′ for one genderless coupling interface, which facilitates modularity and the creation of biopharmaceutical assemblies using various pipe diameters. [0099] In a variant shown in FIG. 6 , the snap-fitting tabs 6 each comprise an axial extension 61 which extends the tab frontward, thereby forming an extra length projecting beyond the body of the opposing connector in the coupling position. All other characteristics are similar or identical to what has been described above. There is not necessarily a protective cover in this mode. [0100] In the illustrated example, the axial longitudinal extension 61 of the snap-fitting tabs of the second connector 1 ′ extends significantly beyond the body 18 of the first connector, and therefore the end 62 of this extension is at a distance from the pipe, allowing the operator to manipulate the tab or tabs with his fingers. [0101] In addition, these frontward axial extensions form protective elements for the pipe clamp 3 of the first connector, preventing a damaging edge of the clamp from coming into direct contact with an external element 90 . [0102] As is apparent from FIG. 6 , in a symmetrical manner, the first connector 1 also comprises axial longitudinal extensions of the snap-fitting tabs so as to protect the second pipe clamp 3 ′. However, symmetry is not required because the axial extensions of the tabs are not directly implicated in the coupling compatibility of the genderless connectors. [0103] In a variant shown in FIG. 7A , each of the first and second connectors is equipped with an aseptic sealing membrane prior to its coupling. A first membrane 73 is arranged on the front face of seal 13 , and similarly a second membrane 74 is arranged on the front face of seal 13 ′ of the second connector. [0104] Note that in this embodiment, each of the connectors comprises only two snap-fitting tabs in order to leave enough room for installation and removal of the aseptic sealing membrane. [0105] A primary clip-on position is defined, which can be considered an intermediate position in the present embodiment. In this primary clip-on position, the transverse portion 6 a of the snap-fitting tabs 6 is placed in abutment against the stop surfaces 8 , but the collars 16 , 16 ′ are not in contact with one another and are separated by a free space, each collar being, in this position, set slightly back from the interface plane P. [0106] All other elements not described again here are assumed to be identical or similar to what was presented for the first embodiment. [0107] In the initial connecting stage, the connectors 1 , 1 ′ are apart from each other and the fluid spaces 71 , 72 are isolated from each other and from the ambient air. [0108] To perform the connection, first a primary coupling is made between the first and second connectors 1 , 1 ′, as described above, in a maneuver similar to that described for the first embodiment. FIG. 7B illustrates this primary coupling position where the aseptic membranes are sandwiched between the seals 13 , 13 ′ of the two connectors, which are exerting a certain axial pressure against one another. [0109] Next, the aseptic sealing membranes 73 , 74 are removed by pulling them radially as illustrated by arrow R of FIG. 7B . [0110] The two fluid spaces 71 , 72 have now been placed in communication without having been in contact with the ambient air. [0111] For some applications, this represents a sufficient solution for a connection satisfying conditions of isolation and sterility with respect to ambient air. [0112] Advantageously, when using a protective cover 5 such as the one presented above and as illustrated in FIG. 7C , the movement of closing the cover is utilized to exert an axial pressure. As the tapered shapes of the annular inner groove have a trapezoidal cross-section, closing the cover causes additional axial travel in the coupling to bring the collars 16 , 16 ′ closer together and thus increase the contact pressure between the two seals. [0113] When a protective cover is used in this manner, the axial pressure of the primary coupling may be substantially reduced to facilitate removal of the aseptic sealing membranes. [0114] In addition, an optional feature is provided that is compatible with all variants mentioned above: this is the integration of at least one identifier 60 , such as a barcode or electronic tag (for example RFID). Preferably, this identifier is provided on the first connector, and/or on the second connector, and/or on the protective cover as illustrated in FIG. 1 . The identifier could also be a colored dot or a color coding of the part itself. [0115] Note that according to the invention, the number N of snap-fitting tabs may be any positive integer from 1 to ten.

Fluid-connection device for connecting a flexible pipe defining a first fluid space to a second flexible pipe or a flexible fluid enclosure in a biopharmaceutical assembly, includes a first connector and a second connector equivalent thereto, the first connector and second connector adapted to be coupled together in a genderless manner, by an insertion movement that is essentially an axial translation, into a relative coupling position, which defines a mating plane, each of the connectors including, in an alternating manner along the circumferential direction, N flexible snap-fitting tabs and N stop surfaces, the flexible snap-fitting tabs projecting axially forwards relative to the mating plane, and the stop surfaces being set back from the mating plane so that, in the coupling position, the snap-fitting tabs of one connector clip into place on the stop surfaces of the other connector, such that the resulting position is locked by the snap-fitting tabs.

BACKGROUND OF THE INVENTION [0001] The present invention relates to a linear guide bearing apparatus for use in, for example, industrial machines. [0002] For example, an apparatus shown in FIG. 7 is known as a related linear guide bearing apparatus of such a kind (see, for instance, Patent Document 1). [0003] This linear guide bearing apparatus has a guide rail 1 extending in an axial direction, and a slider 2 bridged across the guide rail 1 to be able to be displaced with respect thereto in the axial direction. Two rows of rolling-element rolling grooves 3 extending in the axial direction are formed in each of both widthwise side surfaces of the guide rail 1 , so that a total of four rolling-element rolling grooves 3 are formed. [0004] Rolling-element rolling grooves 5 respectively opposed to the rolling-element rolling grooves 3 are formed in the inner side surfaces of both sleeve portions 4 of the slider body 2 A of the slider 2 . These rolling-element rolling grooves 3 and 5 constitute a load raceway. [0005] Many cylindrical rollers 6 serving as rolling elements are rollably loaded into the load raceway. Rolling of the rollers 6 enables the slider 2 to be displaced on the guide rail 1 in the axial direction with respect thereto. [0006] As the slider 2 is displaced, the cylindrical rollers 6 intervening between the guide rail 1 and the slider 2 roll and move to an axial end of the slider 2 . However, it is necessary for consecutively moving the slider 2 in the axial direction to endlessly circulate these cylindrical rollers 6 . [0007] Thus, cylindrical holes 7 axially penetrating through the sleeve portions 4 of the slider body 2 A are formed. Circulating sleeves 8 , the inside of each of which is used as a path (a rolling element path) 8 a for the cylindrical roller 6 , are fitted into these holes 7 . Also, end caps 9 are respectively fixed to both axial ends of the slider body 2 A by screws. A direction change path 10 , which is curved like an arc and communicates between the load raceway and the rolling element path 8 a is formed in each of the end caps 9 . Thus, an endless raceway for the cylindrical rollers 5 is formed. [0008] Incidentally, the direction change path 10 communicating between the upper rolling-element path 8 a and each of both the lower rolling-element rolling grooves 3 and 5 is disposed to cross the direction change path 10 , which communicates between the lower rolling-element path 8 a and each of both the upper rolling-element rolling grooves 3 and 5 , in a grade separation manner. [0000] [Patent Document 1] JP-A-2002-54633. [0009] In the related linear guide bearing apparatus, the rolling element path 8 a of each of the circulating sleeves 8 fitted into the holes 7 of the slider body 2 A is a path for the cylindrical roller 8 and is cross-sectionally rectangular. Thus, it is necessary for forming the endless circulating raceway that when the circulating sleeves 8 are inserted into the holes 7 , an operation of carefully inserting or turning the circulating sleeves 8 is performed so that the phase of each of the circulating sleeves 8 is adjusted to an appropriate value with respect to the associated hole 7 . The related linear guide bearing apparatus has a drawback in that this operation is troublesome. SUMMARY OF THE INVENTION [0010] The invention is accomplished to solve the drawback. An object of the invention is to provide a linear guide bearing apparatus enabled to easily achieve an operation of adjusting the phase of the circulating sleeves and also enabled to smoothly perform assembly thereof. [0011] To achieve the foregoing object, according to a first aspect of the invention, there is provided with a linear guide bearing apparatus including a guide rail, which has a rolling element rolling groove axially extends, and a slider, which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail and is bridged across the guide rail to be able to be axially displaced with respect thereto by rolling a large number of rollers serving rolling elements, and which are inserted into a load raceway formed between the rolling element rolling grooves. The slider includes a slider body, in which a circulating sleeve is fitted into each of holes axially penetrating therethrough and has an inner part used as a rolling element path, and an end cap that has a curved direction change path communicating between the load raceway and the rolling element path and that is fixed at an axial end portion of the slider body. The first aspect linear guide bearing apparatus features that a projecting portion extending along an axial end surface of the slider body is provided at least at one of the circulating sleeves. [0012] According to the second aspect of the invention, there is provided with the linear guide bearing apparatus according to the first aspect, further including a concave portion, into which the projecting portion is fitted, provided in the end cap, wherein a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the projecting portion into the concave portion. [0013] According to the third aspect of the invention, there is provided with the linear guide bearing apparatus according to the first or second aspect, wherein the projecting portion constitutes a part of the direction change path. [0014] According to a fourth aspect of the invention, there is provided with the linear guide bearing apparatus according to the first aspect, further including a concave portion provided in an axial end portion of the slider body, and a convex portion to be fitted into the concave portion provided on the projecting portion, wherein a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the convex portion into the concave portion. [0015] According to a fifth aspect of the invention, there is provided with the linear guide bearing apparatus according to one of the first to fourth aspects, wherein the circulating sleeve with the projecting portion includes a first circulating sleeve constituent member and a second circulating sleeve constituent member, into which the circulating sleeve is split along a central axis thereof, and a color for discriminating between the first circulating sleeve constituent member and the second circulating sleeve constituent member is applied to at least one of the first circulating sleeve constituent member and the second circulating sleeve constituent member. [0016] According to a sixth aspect of the invention, there is provided with a linear guide bearing apparatus including a guide rail, which has a rolling element rolling groove axially extends, and a slider, which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail and is bridged across the guide rail to be able to be axially displaced with respect thereto by rolling a large number of rollers serving rolling elements, and which are inserted into a load raceway formed between the rolling element rolling grooves. The sixth aspect linear guide bearing apparatus features that a color for discriminating paired components, which have object shapes, among components of the linear guide bearing apparatus, is applied to at least one of the paired components. [0017] According to the first aspect linear guide bearing apparatus of the invention, application of torque, which is used for rotating the circulating sleeve, to the projecting portion is facilitated by operating the projecting portion, which is provided at least at one of the circulating sleeves and extends along the axial end surface of the slider body, after the circulating sleeve is inserted into the hole of the slide body. Consequently, an operation of adjusting the phase of the circulating sleeve with respect to the hole of the slider body is facilitated. [0018] Also, even in a case where the circulating sleeve is firmly fixed in the hole of the slider body by intermediate-fitting or interference-fitting so as to increase the stiffness of the circulating sleeve and as to suppress the vibrations and the noises, the torque causing the circulating sleeve to be fitted into the hole to rotate can be applied by utilizing the projecting portion. Consequently, the operation of adjusting the phase of the circulating sleeve can easily be performed. [0019] The second aspect linear guide bearing apparatus features that a concave portion, into which the projecting portion is fitted, is provided in the end cap, and that a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the projecting portion into the concave portion, in addition to the features of the first aspect linear guide bearing apparatus of the invention. Thus, when the apparatus is fabricated, the phase of the circulating sleeve can easily be adjusted. [0020] The third aspect linear guide bearing apparatus of the invention features that the projecting portion constitutes a part of the direction change path, in addition to the features of the first or second aspect linear guide bearing apparatus of the invention. Thus, the number of the components can be reduced. Also, the step-like parts in the circulating path, in which the rolling elements are circulated, are reduced. Consequently, the rolling elements can smoothly be passed therethrough. [0021] The fourth aspect linear guide bearing apparatus of the invention features that a concave portion is provided in an axial end portion of the slider body, that a convex portion to be fitted into the concave portion is provided on the projecting portion, and that a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the convex portion into the concave portion, in addition to the features of the first aspect linear guide gearing apparatus of the invention. Thus, when the apparatus is fabricated, the phase of the circulating sleeve can easily be adjusted. [0022] Also, because the concave portion serves as a mark indicating the hole, into which the circulating sleeve is inserted, the circulating sleeve can be prevented from being inserted into the erroneous hole. [0023] The fifth aspect linear guide bearing apparatus of the invention features that a color for discriminating between the first circulating sleeve constituent member and the second circulating sleeve constituent member is applied to at least one of the first circulating sleeve constituent member and the second circulating sleeve constituent member, in addition to the feature of one of the first to fourth aspect linear guide bearing apparatuses. Thus, the first circulating sleeve constituent member and the second circulating sleeve constituent member can be discriminated from each other at a glance and also can be combined with each other. [0024] The sixth aspect linear guide bearing apparatus of the invention features that a color for discriminating paired components, which have object shapes, among components of the linear guide bearing apparatus, is applied to at least one of the paired components. Thus, the paired components of the linear guide bearing apparatus can be discriminated from each other at a glance and also can be combined with each other. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is an embodiment of the invention. [0026] FIG. 2 is an explanatory view illustrating the configuration of a circulating sleeve shown in FIG. 1 . [0027] FIG. 3 is a left side view illustrating the circulating sleeve shown in FIG. 1 . [0028] FIG. 4 is a view partly illustrating an end cap. [0029] FIG. 5 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is another embodiment of the invention. [0030] FIG. 6 is a view partly illustrating an axial end surface of a slider body. [0031] FIG. 7 is a partly cutaway explanatory view illustrating a related linear guide bearing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0032] Hereinafter, an embodiment of the invention is described with reference to the accompanying drawings. FIG. 1 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is an embodiment of the invention. FIG. 2 is an explanatory view illustrating the configuration of a circulating sleeve shown in FIG. 1 . FIG. 3 is a left side view illustrating the circulating sleeve shown in FIG. 1 . FIG. 4 is a view partly illustrating an end cap. FIG. 5 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is another embodiment of the invention. FIG. 6 is a view partly illustrating an axial end surface of a slider body. Incidentally, in this embodiment, parts, which are the same as or correspond to those described by referring to FIG. 7 , are designated by the same reference characters used in FIG. 7 . Thus, the description of such parts is omitted herein. [0033] As shown in FIGS. 1 to 3 , a linear guide bearing apparatus, which is an embodiment of the invention, has a projecting portion 20 that is provided at an end portion of a circulating sleeve 8 and extends along an axial end surface of a slider body 2 A. [0034] The circulating sleeve 8 including the projecting portion 20 is split along a central axis thereof into and comprises two parts, that is, a first circulating sleeve constituent member 8 R and a second circulating sleeve constituent member 8 L. A positioning convex portion 11 and a positioning concave portion 12 are respectively formed at a position on the splitting surface of one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L, and at a position in that of the other sleeve constituent member so that the position of the convex portion 11 corresponds to the position of the concave portion 12 when the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L are fitted to each other. The circulating sleeve 8 is formed by superposing the splitting surfaces of first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L so that the positioning convex portion 11 , which is formed at a position on the splitting surface of one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L, is fitted into the positioning concave portion 12 formed in that of the other sleeve constituent member. A rolling element path 8 a is formed in the circulating sleeve 8 . During this state, the circulating sleeve 8 is inserted into a hole 7 of the slider body 2 A. A color is applied to the entirety of at least one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L. This color enables that the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L can be discriminated from each other at a glance and also can be combined with each other. In this case, when the circulating sleeve constituent members 8 R and 8 L are formed of resin materials, preferably, a method of applying a color thereto is to apply a color directly to each of the resin materials. In a case where the circulating sleeve constituent members 8 R and 8 L are formed of metallic materials, and where it is difficult to apply a color directly to each of the metallic materials, the color may be applied to the members 8 R and 8 L by performing secondary processing, such as painting. [0035] Also, application of torque, which is used for rotating the circulating sleeve 8 , to the projecting portion 20 is facilitated by operating the projecting portion 20 after the circulating sleeve 8 is inserted into the hole 7 of the slide body 2 A. Consequently, the adjustment of the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A is facilitated. [0036] Even in a case where the circulating sleeve 8 is firmly fixed in the hole 7 of the slider body 2 A by intermediate-fitting or interference-fitting so as to increase the stiffness of the circulating sleeve 8 and as to suppress the vibrations and the noises, the torque causing the circulating sleeve 8 to be fitted into the hole 7 to rotate can be applied by utilizing the projecting portion 20 . Consequently, an operation of adjusting the phase of the circulating sleeve can easily be performed. [0037] Also, in this embodiment, an inner periphery side raceway 10 a of a direction change path 10 is formed in the projecting portion 20 so as to reduce the number of components. In this case, as shown in FIG. 4 , a positioning concave portion 30 , whose bottom part is formed as an outer periphery side raceway 10 b , is provided in the end cap 9 . The projecting portion 20 is fitted into this positioning concave portion 30 to thereby adjust the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A. Thus, the phase of the circulating sleeve 8 can easily be adjusted at fabrication of the apparatus. [0038] Also, the projecting portion 20 is formed integrally with the inner periphery side raceway 10 a of the direction change path 10 . Thus, step-like parts in the path, in which the cylindrical rollers 6 are circulated, can be reduced. Consequently, the cylindrical rollers 6 can smoothly be passed therethrough. [0039] In this embodiment, a projection 32 is provided at the other end portion of the circulating sleeve 8 so that the projection 32 is fitted into a hole 31 (see FIG. 4 ) provided in the opposite end cap 9 . The circulating sleeve 8 is more firmly fixed by fitting the projection 32 into the hole 31 . [0040] Incidentally, the linear guide bearing apparatus of the invention is not limited to the aforementioned embodiment. The embodiment can appropriately be altered without departing from the spirit and scope of the invention. [0041] For example, although the foregoing description of the embodiment has described the case that the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A is adjusted by fitting the projecting portion 20 at the side of the circulating sleeve 8 into the positioning concave portion 30 provided in the end cap 9 , instead, the following configuration may be employed. That is, as shown in FIGS. 5 and 6 , a convex portion 40 is provided on a side of the projecting portion 20 of the circulating sleeve 8 , which faces an axial end surface of the slider body 2 A. Also, a concave portion 41 , into which the convex portion 40 is fitted, is provided in the axial end surface of the slider body 2 A. The phase of the circulating sleeve 8 with respect the hole 7 of the slider body 2 A is adjusted by fitting the convex portion 40 into the concave portion 41 . [0042] Referring to FIG. 6 , in this case, the concave portion 41 serves as a mark indicating the hole 7 (the lower one, as viewed in FIG. 6 ), into which the circulating sleeve 8 is inserted. Thus, the circulating sleeve 8 can be prevented from being inserted into the erroneous hole 7 (the upper one, as viewed in FIG. 6 ). Incidentally, the circulating sleeve 8 is inserted from an opposite side into the upper hole shown in FIG. 6 . Similarly, the convex portion 40 provided in the projecting portion 20 of the circulating sleeve 8 is fitted into the concave portion 41 of the slider body 2 A. [0043] Also, although the foregoing description of the embodiment has described the case, in which a color is applied to at least one of paired right circulating sleeve members 8 R and 8 L, by way of example, the invention is not limited to this case. A color is applied to at least one of paired components, which have symmetric shapes, among components of the linear guide bearing apparatus so as to discriminate the paired components from each other. Thus, the invention can obtain effects of smoothly performing the fabrication of the linear guide bearing apparatus. Additionally, it is unnecessary to apply the color to the entirety of each of the components. A color may be applied to positions or a range on a part of each of the components so that the components can easily and visually be checked.

It is a linear guide bearing apparatus comprising a slider 2 that has a slider body 2 A provided with a holes 7 , into which a circulating sleeve 8 , whose inside space serves as a rolling-element path 8 a, is fitted, and also has an end cap 9, which has a curved direction change path 10 communicating between a load raceway and a rolling-element path 8 a and is fixed to an associated axial end portion of the slider body 2 A. The linear guide bearing apparatus further comprises a projecting portion 20, which is provided at least at one of end portions of the circulating sleeve 8 and extends along the axial end portion of the slider body 2 A.

PRIORITY CLAIM [0001] In accordance with 37 CFR §1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority as a continuation-in-part of U.S. patent application Ser. No. 14/045,386, entitled “DEVICE OF TREATING MANHOLE ELECTRICAL FIRES”, filed Oct. 3, 2013. The contents of which the above referenced application is incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention relates to the field of fire prevention, and more particularly to a device for placement around a manhole for dispersion of a fire suppressant to shield a worker while working within a manhole should a fire occur. BACKGROUND OF THE INVENTION [0003] In many cities the utilities are located beneath the surface of the earth, usually beneath the surface of the streets. These utilities are usually placed in tunnels or conduits. In the older cities, such as New York City, these utilities have been located in these tunnels or conduits for many years/decades. Over time, the conduits which carry these utilities wear out and break. A serious problem is the failure of electrical transmission lines in conduits and tunnels. These failures usually result in fires which must be quickly extinguished to prevent further damage. [0004] While it is desirable to replace very old utilities in conduits and tunnels, it is not always practical. Due to financial restraints and other limitations, most of these electrical transmission lines have not been replaced. Unfortunately, failure of older electrical transmission lines can result in an electrical fire. These fires are commonly discovered when smoke is seen arising from manhole covers in the streets and sidewalks. It has been estimated by Consolidated Edison that there are approximately 40 electrical fires per day under the streets of New York City. [0005] The cost of repairing and replacing the electrical transmission lines damaged by these fires is approximately $100,000.00 per linear foot of transmission line. Therefore, it is imperative that these fires be extinguished as quickly as possible. Inspection of lines can help pinpoint potential trouble areas. Unfortunately, inspection of the lines can trigger a fire. For instance, the opening of a manhole cover can provide the oxygen needed to support a fire. Similarly, a lineman performing an inspection may disturb a conduit resulting in arcing of electric lines, possibly triggering a fire. [0006] Normally a lineman inspecting a potential problem area occurs while electrical power is still flowing through the lines. The inspection takes place within the manhole wherein a lineman inserts himself into the manhole. Typically a ladder is placed through the manhole and the lineman climbs down the ladder to permit inspection from within. Unfortunately the lineman can trigger a fire, or simply be in the wrong place at the wrong time. There have been many instances wherein a fire begins while the lineman is on the ladder. For instance, a fire may be smoldering as evidence by smoking coming out of the manhole. A lineman or fireman may then enter the manhole, and without notice, the smoldering may burst into an all encompassing fire. In many such instances, the individual who climbed into the manhole is now at risk of injury or death. [0007] What is needed is a device that provides fire protection to the individual that climbs through the manhole for servicing of the electrical grid in the tunnels beneath the ground surface. DESCRIPTION OF THE PRIOR ART [0008] U.S. Pat. No. 6,834,728 discloses a system for extinguishing a fire in a tunnel. The system includes a conduit for delivering a fire extinguishing liquid and a trough extending parallel to the conduit for receiving liquid from the conduit. A carriage is arranged to move on a track which includes an upper edge of the trough. The carriage carries a pump having a nozzle, a video camera, and an inlet; each of which can be controlled robotically from a remote control station. The inlet is deployed in the trough to draw liquid from the trough. [0009] U.S. Pat. No. 7,096,965 discloses a method of proportioning a foam concentrate into a non-flammable liquid to form a foam concentrate/liquid mixture and create a flowing stream of the foam concentrate/liquid mixture. Nitrogen is introduced into the stream of the foam/liquid mixture to initiate the formation of a nitrogen expanded foam fire suppressant. The flowing stream carrying the nitrogen expanded foam is dispensed, which completes the full expansion of the nitrogen expanded foam fire suppressant, into the confined area involved in the fire, thereby smothering the fire and substantially closing off contact between combustible material involved in the fire and the atmosphere. The apparatus of this invention is adapted for expanding and dispensing foam and includes a housing defining an interior through which extends a discharge line. The ends of the housing are closed about the ends of the discharge line, and the ends of the discharge line extend beyond the ends of the housing to define a connector at one end for receiving a stream of foam concentrate/liquid and at the opposite end to define the foam dispensing end of the apparatus. A portion of the discharge line in the housing defines an eductor for the introduction of expanded gas into the stream of foam concentrate/liquid flowing through the discharge line. [0010] U.S. Pat. No. 7,124,834 discloses a method for extinguishing a fire in a space such as a tunnel. The method includes spraying a fire extinguishing medium into the space by spray heads. In a first stage of the method, the flow and temperature of the hot gases produced by the fire are influenced by spraying an extinguishing medium into the space, especially by creating in the space at least one curtain of extinguishing medium. At least some spray heads in the space are pre-activated into a state of readiness. In a second stage of the method, at least one spraying head is activated to produce a spray of extinguishing medium. [0011] U.S. patent application Ser. No. 11/680,803 is entitled “Process for Fire Prevention and Extinguishing”, the contents of which are incorporated herein by reference. In this application, a process for retarding or extinguishing conflagrations using a fire suppressant in water is disclosed. The reaction of the water with the polymer creates a gel-like substance with a viscosity that allows the mixture to be readily pumped through a standardized 2.5 gallon water based fire extinguisher, yet viscous enough to cover vertical and horizontal surfaces to act as a barrier to prevent fire from damaging such structures, minimizing the manpower needed to continuously soak these structures. SUMMARY OF THE INVENTION [0012] A device for suppressing the spread of and extinguishing electrical fires in manhole areas. The device includes a distribution ring that is placed over a manhole and distributes a fire suppressant into the manhole covering the individual and the area direction around the ladder used by the individual to enter the manhole. Known fire suppressants have substantially superior fire suppression and extinguishing properties over plain water and are preferably non-conductive. [0013] Accordingly, it is an objective of the present invention to provide a device for placement in a manhole for suppressing fires in confined areas. [0014] It is a further objective of the present invention to provide a device that is manually triggered by the individual in the manhole, or a person outside the manhole, to release material capable of extinguishing and suppressing the spread of electrical fires in the manhole; the manual trigger is a solenoid operated valve operated by switches attached to the end of extension cords. [0015] It is a further objective of the present invention to provide a device that is manually triggered by the individual in the manhole, or a person outside the manhole, to release material capable of extinguishing electrical fires and suppressing the spread of electrical fires in the manhole; the manual trigger is a solenoid operated valve operated by wireless RF controllers. [0016] It is a further objective of the present invention to provide a device that is automatically triggered to release material capable of extinguishing electrical fires and suppressing the spread of electrical fires in the manhole. The automatic trigger is a heat sensitive nozzle that is ready to dispense material upon the presence of heat. [0017] It is yet another objective of the present invention to provide a device that sprays a material coating over the individual calculated to provide the individual time to extract themselves from the manhole. [0018] It is still yet another objective of the present invention to provide a device to work with a unique admixture of fire suppressant which has viscosity sufficient to enable it to retain positioning for a period of time. The viscosity also enables the admixture to adhere to horizontal, vertical, inclined, and curved surfaces. [0019] It is a still further objective of the present invention to provide a device for protecting of personnel, extinguishing or suppressing of an electrical fire. [0020] Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. BRIEF DESCRIPTION OF THE FIGURES [0021] FIG. 1 is a pictorial view of a device for treating manhole electrical fires; [0022] FIG. 2 is a pictorial view of the device using a wireless transmitter; [0023] FIG. 3 is a pictorial view of the distributor nozzle; [0024] FIG. 4 is a side view of the distributor nozzle; and [0025] FIG. 5 is a cross sectional view of the distributor nozzle. DETAILED DESCRIPTION OF THE INVENTION [0026] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated. [0027] The present invention relates to a unique technique or method of extinguishing electrical fires and suppressing the spread of electrical fires. This unique technique utilizes a fire suppressant in an amount sufficient to extinguish an electrical fire and suppress the spread of the electrical fire. Know fire suppressants marketed under the brand name of FIREICE, CEMDAL AQUA SHIELD, BARRICADE, THERMO-GEL, WILDFIRE AFG FIREWALL, BIOCENTRAL BLAZETAMMER, PHOS-CHEK INSUUL, and THERMO GEL. As used herein, a “fire suppressant” composition is meant to be inclusive of all components of the composition. In some embodiments, the fire suppressant composition comprises one or more fire suppressant compounds. In other embodiments, the fire suppressant composition comprises one or more common components of fire suppressant formulations, such as: fire suppressant salts, conventional fire suppressants, corrosion inhibitors, spoilage inhibitors, foaming agents, non foaming agents, flow conditioners, stability additives, thickening agents, conventional fire suppressants or the like. In some embodiments, the fire suppressant or compositions thereof is in dry form. In other embodiments, the fire suppressant or compositions thereof are hydrated. The fire suppressant or compositions thereof can be a liquid or semi-liquid form, such as, for example, gel having varying viscosities. The fire suppressant compositions can be any known fire suppressants, including biodegradable, super absorbent, aqueous based polymers. Examples of these polymers are cross-linked modified polyacrylamides/potassium acrylate or polyacrylamides/sodium acrylate. Other suitable polymers include, albeit not limited to, carboxy-methylcellulose, alginic acid, cross-linked starches, and cross-linked polyaminoacids. [0028] Referring to the Figures, the present invention relates to a device used to protect personnel that are within a manhole, which could be subject to an electrical fire within the manhole. Electrical fires present different and unique problems pertaining to how these fires should be extinguished and suppressed. Water is normally used to fight fires because it can quickly cool down the burning material, there is usually a large supply of it ready for use, and it is relatively inexpensive. However, water and electricity are harmful, if not deadly to individuals, when brought into contact with each other. Normally, when water hits an active electrical circuit or electrical component, it shorts out the circuit or component, which usually results in destruction of the circuit or component. Further, when individuals are in close proximity to the water contacting the electricity, there is a strong likelihood that the water will act as a conductor and conduct the electricity to the individuals, resulting in serious injury or death of the individuals. Since water spreads rapidly in all directions on surfaces, electricity which comes in contact with the water will be conducted to wherever the water flows. Because it is difficult to prevent water from flowing to certain areas, there is a strong likelihood that individuals will be injured or killed when they come in contact with this water. [0029] In the preferred embodiment of the present invention, a fire suppressant having properties in an amount which enable the fire suppressant to be applied over the individual and remain within the confined area due to its relatively high viscosity. The properties of the admixture, in particular its viscosity, should enable the admixture to be applied to remain on vertical, horizontal, and curved surfaces of the ladder used by the individual to enter the manhole. Unlike pure water, the known fire suppressants do not provide an electrically conductive path permitting the individual time to get out of the manhole without being electrocuted. The present invention adds a predetermined amount of the fire suppressant to obtain an admixture which has properties that enable the admixture to suppress the spread of an electrical fire and extinguish any fire that has attached itself to the individual. The adherence of the admixture of fire suppressant to the clothing of the individual lowers the temperature of the clothing below a combustion temperature thereby giving the individual time to exit the manhole. In addition, adherence of the admixture of fire suppressant to the clothing should maintain moisture content at a level which suppresses the spread of the fire by preventing combustion of the clothing from hot embers and/or flames. Further, placing the admixture upon exposed skin deters burning of the skin. [0030] Currently, firefighters apply water to the electrical conduits/components which are on fire and also to adjacent conduits/components because it is difficult to control where the water goes. This contact of water on electrical conduits/components that are not on fire results in substantial unnecessary damage to these conduits/components. The present invention, on the other hand, enables a controlled dispersion of fire suppressant to a specific area for the primary purpose of protecting the individual from the fire, and giving the individual time to escape the manhole. The mixture adheres to the individual and the ladder, without affecting adjacent conduits/components. Thus, a substantial safety factor is gained because electrical conduits/components are not sprayed, and even if they are sprayed, the admixture should not be conductive. [0031] When there are electrical fires in underground tunnels or conduits, the firefighters contact the electrical utility to have the electrical power turned off so they can fight the fire. In rare instances, the electrical power is not turned off which may result in serious injury and/or death of the firefighters when they apply water to the electrical fire. The present invention produces an admixture having properties such that the admixture will not readily flow or run from the area into which the admixture has been applied. If the fire suppressant contains a large amount of water, if the admixture is applied to a live electrical wire or component, the admixture should be such that electricity will not travel back to the firefighter due to its physical properties. [0032] Referring to the Figures, a container 10 holding the fire suppressant is positioned a distance from a manhole 100 shown with the manhole cover 102 removed and a ladder 104 placed within the manhole 100 . Within the manhole are utilities in an underground tunnel or conduit, not shown. These utilities can be electrical cables, telephone lines, water supply lines, and so forth. The manhole 100 permits individuals to gain access to the underground tunnel. [0033] The container 10 holds a mixture of fire suppressant in an amount to form an admixture. The container 10 can be premixed or mixed on location. The container 10 can hold from 5 to 30 gallons of the admixture, the higher amount providing the longer dispensing period and thus providing the individual within the manhole time to exit as necessary. The admixture is directed into the manhole 100 by use of a distribution ring 14 that is fluidly coupled to the container 10 by a fluid hose 12 . The hose can be 10-50 foot long allowing the placement of the container a distance from the manhole 100 . Quick release couplings 18 and 19 are used to connect the fluid hose 12 to the container 10 and distribution ring 14 . The distribution ring 14 is constructed an arranged to be placed about the circumference of the manhole 100 opening so that an individual can enter and exit uninhibited. The distribution ring 14 has a plurality of spray nozzles 16 to direct the admixture into the manhole 100 should an individual working within the manhole 100 require fire protection. The spray nozzles 16 are constructed and arranged to distribute an amount of the admixture in sufficient quantity to cover the individual, the ladder, and the immediate area beneath the manhole. If the individual's clothing is on fire, the admixture will extinguish the fire and suppress the spread of the fire. The admixture will also protect the individual's skin from exposure to the fire. Further, the admixture will inhibit the fire from damaging the integrity of the ladder so as to provide the individual with sufficient time to exit the manhole. [0034] The container 10 can be manually discharged like a conventional fire extinguisher wherein handle 20 can be manually operated by a co-worker monitoring the individual within the manhole 100 . A solenoid 22 is also positioned at the container 10 allowing for a remote discharge of the container 10 . In the preferred embodiment, a first remote activator 24 is tethered to the solenoid 22 by a cable 26 . Should a need occur, the co-worker monitoring the individual within the manhole 100 may activate the system by depressing a trigger switch located on the remote activator 24 which opens the solenoid 22 allowing for the disbursement of the admixture within the container 10 to the manhole. The cable 26 can be of a length that allows the co-worker quick access for disbursement yet freedom to continue other duties. It is contemplated that the container 10 is mounted on a vehicle. By way of example, a coworker may place the first remote into the cabin area in adverse weather conditions wherein the coworker can monitor the manhole 100 from a remote location, should a fire erupt in the manhole 100 while an individual is within the manhole 100 , the coworker could immediately trigger a discharge. [0035] In addition, a second remote activator 28 is tethered to the solenoid 22 by a cable 30 that allows the worker or fireman who entered the manhole 100 an opportunity to save himself at the first sign of a problem. Similar to the first remote activator 24 , the second remote activator 28 is coupled to the solenoid 22 and can be operated by a trigger switch on the remote activator 28 . It is contemplated that a remote activator 28 is attached to the individual, such as their work belt, every time they enter a manhole 100 to perform inspection. As previously mentioned, electrical arcing may occur at any time and the larger volume of air allowed by the removal of the manhole cover 102 may result in an unexpected fire burst. Similarly, where a fireman is called in to determine the reason for some arising from a manhole 100 , the removal of the manhole 100 cover may allow a volume of air to enter the area to support full blown combustion. It should be noted that even if an electrical grid is turned off for inspection, a smoldering fire may irrupt irrespective of the presence of electricity. In manholes that lead to tunnels, the worker may leave the second remote activator 28 at the bottom of the ladder 104 . Should a fire occur, the worker that returns to the ladder 104 can active the system providing a shower of fire suppressant material that will give him the time necessary to escape the manhole. [0036] A variation of the cabled remote is the use of a wireless transmitter 32 which works on a radio frequency. The transmitter would signal a receiver 34 mounted to the solenoid 22 or a repeater mounted at the entrance of the ladder that would signal the solenoid mounted receiver 34 . At a minimum, a 2.4 GHz transmitter should be suitable to placed within the manhole 100 and transmit to a receiver, without a repeater, if the receiver is positioned with 30 feet of the manhole 100 . Battery condition of the solenoid, whether operated by a cabled trigger switch or a wireless transmitter 32 can be verified by use of an indicator light that indicates the condition of the battery is sufficient for operation. Another light indicator can be employed to verify the container is filled with fluid and pressurized. Lithium battery technology would allow a replacement period expected to exceed ten years as the system is to be used only for emergencies, and the battery draw during that time would be limited to low draw LED operational indicator lights. [0037] In a preferred embodiment, the wireless transmitter 32 is mounted to a wrist band 36 that can be positioned around an individual's wrist before they enter the manhole 100 . Radio frequency has a drawback when placed beneath the ground level requiring the wireless transmitter 32 to be placed within a range of the manhole 100 to assure proper operation. A proximity sensor can be used to assure the transmitter and receiver is within operating range, with a flashing light on the both the solenoid and the receiver to indicate if the devices are out of range. It should be noted that while a wrist band is described, any type of attachment convenient to the individual is contemplated include a pendant worn around the neck and belt attachment similar to a garage door opener bracket. [0038] Referring to FIG. 3 , the container 10 can be charged by a compressed gas container 40 . The container 10 can again be discharged like a conventional fire extinguisher wherein handle 20 can be manually operated by a co-worker monitoring the individual within the manhole 100 . The solenoid 22 is positioned on the container 10 allowing for a remote discharge by use of a wireless transmitter 42 that can be carried by the worker, or attached to the worker wherein the wireless transmitter operates automatically such as by fire or heat. [0039] The container 10 holds the fire suppressant which is directed into the manhole 100 by use of a distribution nozzle 44 that is fluidly coupled to the container 10 by a fluid hose 12 . The hose can be 10-50 foot long allowing the placement of the container a distance from the manhole 100 . The distribution nozzle 44 is constructed and arranged to be placed over the edge of the manhole 100 opening so that an individual can enter and exit uninhibited. The distribution nozzle 44 includes a rigid holder which consists of a hanger pipe that is of a length to place the distribution nozzle 44 beneath the street surface and an elbow 48 that allows for a 90 degree angle change without crimping the admixture flow. The distribution nozzle 44 has a rotating sleeve having a plurality of openings 52 . The sleeve is rotated upon receipt of a fluid flow by use of an impeller 54 that causes rotation upon the pressurized fluid flow into the distribution nozzle 44 . The impeller 54 is but one example of how to cause rotation of the distribution nozzle, the objective of the nozzle is to provide a distribution of the admixture during the situation. The nozzle need only handle a low volume flow of about 10 gallons total allowing for use of a ½″ or less sized distributor. A fixed nozzle may also be used wherein the openings are constructed and arranged to provide an overlapping pattern of admixture distribution. The nozzles are constructed to distribute an amount of the admixture in sufficient quantity to cover the individual, the ladder, and the immediate area beneath the manhole. If the individual's clothing is on fire, the admixture will extinguish the fire and suppress the spread of the fire. The admixture will also protect the individual's skin from exposure to the fire. Further, the admixture will inhibit the fire from damaging the integrity of the ladder so as to provide the individual with sufficient time to exit the manhole. [0040] The viscosity of the admixture of fire suppressant allows attachment to whatever is spayed and the admixture will not move or migrate past the area into which it was introduced. Therefore, the admixture can be delivered to a specific area within a tunnel and it will remain in that area and will not flow into areas that are not sprayed. Spraying the individuals clothing and exposed skin is most preferred, the admixture provides fire extinguishing qualities also provides fire and heat retardant properties. Further, once the individual is within the spray area, noxious and/or toxic gasses are entrapped again providing the individual with additional time to exit the manhole. [0041] In some embodiments, the fire suppressant composition comprises one or more fire suppressant compounds. In other embodiments, the fire suppressant composition comprises one or more common components of fire suppressant formulations, such as: fire suppressant salts, known or conventional fire suppressants, corrosion inhibitors, spoilage inhibitors, foaming agents, non foaming agents, flow conditioners, stability additives, thickening agents, pigments, dyes or the like. [0042] In some embodiments, a conventional fire suppressant comprises penta-bromodiphenyl ether, octa-bromodiphenyl ether, deca-bromodiphenyl ether, short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), tetrabromobisphenol A ether, pentabromotoluene, 2,3-dibromopropyl-2,4,6-tribromophenyl ether, tetrabromobisphenol A, bis(2,3-dibromopropyl ether), tris(tribromophenoxy)triazine, tris(2-chloroethyl)phosphate (TCEP), tris(2-chloro-1-methylethyl)phosphate (TCPP or TMCP), tris(1,2-dichloropropyl)phosphate (TDCP), 2,2-bis(chloromethyl)-trimethylene bis(bis(2-chloroethyl)phosphate), melamine cyanurate, antimony trioxide Sb 2 O 3 (ATO), boric acid, ammonium polyphosphate (APP), aluminum ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide red phosphorous, 1,2-bis(tribromophenoxy)ethane, 2,4,6-tribromophenyl glycidyl ether, tetrabromo phthalic anhydride, 1,2-bis(tetrabromo phthalimide)ethane, tetrabromo dimethyl phthalate, tetrabromo disodium phthalate, decabromodiphenyl ether, tetradecabromodi(phenoxyl)benzene, 1,2-bis(pentabromophenyl)ethane, bromo-trimethyl-phenyl-hydroindene, pentabromobenzyl acrylate, pentabromobenzyl bromide, hexabromobenzene, pentabromotoluene, 2,4,6-tribromophenyl maleimide, hexabromo cyclododecane, N,N′-1,2-bis(dibromonorbornyl dicarbimide)ethane, pentabromochloro-cyclohexane, tri(2,3-dibromopropyl)isocyanurate, bromo-styrene copolymer, tetrabromobisphenol A-carbonate oligomer, polypentabromobenzyl acrylate, polydibromophenylene ether; chlorinated flame retardants such as: dechlorane plus, HET anhydride (chlorendic anhydride), perchloro pentacyclodecane, tetrachloro bisphenol A, tetrachlorophthalic anhydride, hexachlorobenzene, chlorinated polypropylene, chlorinated polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, chlorinated polyether, hexachloroethane; organic phosphorus flame retardants such as: 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo[2,2,2]octane, 2,2-dimethyl-1,3-propanediol-di(neopentyl glycol)diphosphate, 9,10-di hydro-9-oxa-10-phosphaphenanthrene-10 oxide, bis(4-carboxyphenyl)-phenyl phosphine oxide, bis(4-hydroxyphenyl)-phenyl phosphine oxide, phenyl(diphenyl sulfone)phosphate oligomer; phosphorus-halogenated flame retardants such as tris(2,2-di(bromomethyl)-3-bromopropyl)phosphate, tris(dibromophenyl)phosphate, 3,9-bis(tribromophenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]-3,9-di-oxo-undecane, 3,9-bis(pentabromophenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]-3,9-dioxo-undecane, 1-oxo-4-tribromophenoxycarbonyl-2,6,7-trioxa-1-phosphabicyclo[2,2,2]octane, p-phenylene-tetrakis(2,4,6-tribromophenyl)-diphosphate, 2,2-di(chloromethyl)-1,3-propanediol-di(neopentyl glycol)diphosphate, 2,9-di(tribromo-neopentyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]-3,9-dioxo-undecane; nitrogen-based flame retardants or phosphorus-nitrogen-based flame retardants such as melamine, melamine cyanurate, melamine orthophosphate, dimelamine orthophosphate, melamine polyphosphate, melamine borate, melamine octamolybdate, cyanuric acid, tris(hydroxyethyl)isocyanurate, 2,4-diamino-6-(3,3,3-trichloro-propyl)-1,3,5-triazine, 2,4-di(N-hydroxymethyl-amino)-6-(3,3,3-trichloro-propyl-1,3,5-triazine), diguanidine hydrophosphate, guanidine dihydrogen phosphate, guanidine carbonate, guanidine sulfamate, urea, urea dihydrogen phosphate, dicyandiamide, melamine bis(2,6,7-trioxa-phosphabicyclo[2.2.2]octane-1-oxo-4-methyl)-hydroxy-phosphate, 3,9-dihydroxy-3,9-dioxo-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]u-ndecane-3,9-dimelamine, 1,2-di(2-oxo-5,5-dimethyl-1,3-dioxa-2-phosphacyclohexyl-2-amino)ethane, N,N′-bis(2-oxo-5,5-dimethyl-1,3-dioxa-2-phosphacyclohexyl)-2,2′-m-phenyle-nediamine, tri(2-oxo-5,5-dimethyl-1,3-dioxa-2-phosphacyclohexyl-2-methyl)a-mine, hexachlorocyclotriphosphazene; and inorganic flame retardants such as: red phosphorus, ammonium polyphosphate, diammonium hydrophosphate, ammonium dihydrogen phosphate, zinc phosphate, aluminum phosphate, boron phosphate, antimony trioxide, aluminum hydroxide, magnesium hydroxide, hydromagnesite, alkaline aluminum oxalate, zinc borate, barium metaborate, zinc oxide, zinc sulfide, zinc sulfate heptahydrate, aluminum borate whisker, ammonium octamolybdate, ammonium heptamolybdate, zinc stannate, stannous oxide, stannic oxide, ferrocenc, ferric acetone, ferric oxide, ferro-ferric oxide, ammonium bromide, sodium tungstate, potassium hexafluorotitanate, potassium hexafluorozirconate, titanium dioxide, calcium carbonate, barium sulfate, sodium bicarbonate, potassium bicarbonate, cobalt carbonate, zinc carbonate, basic zinc carbonate, heavy magnesium carbonate, basic magnesium carbonate, manganese carbonate, ferrous carbonate, strontium carbonate, sodium potassium carbonate hexahydrate, magnesium carbonate, calcium carbonate, dolomite, basic copper carbonate, zirconium carbonate, beryllium carbonate, sodium sesquicarbonate, cerium carbonate, lanthanum carbonate, guanidine carbonate, lithium carbonate, scandium carbonate, vanadium carbonate, chromium carbonate, nickel carbonate, yttrium carbonate, silver carbonate, praseodymium carbonate, neodymium carbonate, samarium carbonate, europium carbonate, gadolinium carbonate, terbium carbonate, dysprosium carbonate, holmium carbonate, erbium carbonate, thulium carbonate, ytterbium carbonate, lutetium carbonate, aluminum diacetate, calcium acetate, sodium bitartrate, sodium acetate, potassium acetate, zinc acetate, strontium acetate, nickel acetate, copper acetate, sodium oxalate, potassium oxalate, ammonium oxalate, nickel oxalate, manganese oxalate dihydrate, iron nitride, sodium nitrate, magnesium nitrate, potassium nitrate, zirconium nitrate, calcium dihydrogen phosphate, sodium dihydrogen phosphate, sodium dihydrogen phosphate dihydrate, potassium dihydrogen phosphate, aluminum dihydrogen phosphate, ammonium dihydrogen phosphate, zinc dihydrogen phosphate, manganese dihydrogen phosphate, magnesium dihydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, calcium hydrogen phosphate, magnesium hydrogen phosphate, ammonium phosphate, magnesium ammonium phosphate, ammonium polyphosphate, potassium metaphosphate, potassium tripolyphosphate, sodium trimetaphosphate, ammonium hypophosphite, ammonium dihydrogen phosphite, manganese phosphate, dizinc hydrogen phosphate, dimanganese hydrogen phosphate, guanidine phosphate, melamine phosphate, urea phosphate, strontium dimetaborate hydrogen phosphate, boric acid, ammonium pentaborate, potassium tetraborate octahydrate, magnesium metaborate octahydrate, ammonium tetraborate tetrahydrate, strontium metaborate, strontium tetraborate, strontium tetraborate tetrahydrate, sodium tetraborate decahydrate, manganese borate, zinc borate, ammonium fluoroborate, ammonium ferrous sulfate, aluminum sulfate, potassium aluminum sulfate, ammonium aluminum sulfate, ammonium sulfate, magnesium hydrogen sulfate, aluminum hydroxide, magnesium hydroxide, iron hydroxide, cobalt hydroxide, bismuth hydroxide, strontium hydroxide, cerium hydroxide, lanthanum hydroxide, molybdenum hydroxide, ammonium molybdate, zinc stannate, magnesium trisilicate, telluric acid, manganese tungstate, manganite, cobaltocene, 5-aminotetrazole, guanidine nitrate, azobisformamide, nylon powder, oxamide, biuret, pentaerythritol, decabromodiphenyl ether, tetrabromo-phthalic anhydride, dibromoneopentyl glycol, potassium citrate, sodium citrate, manganese citrate, magnesium citrate, copper citrate, ammonium citrate, nitroguanidine. [0043] In some embodiments, the fire suppressant or compositions thereof are in dry form. In other embodiments, the fire suppressant or compositions thereof are hydrated. The fire suppressant or compositions thereof can be a liquid, foam, or semi-liquid form, such as, for example, a gel having varying viscosities. [0044] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. [0045] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. [0046] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

A device for protecting a lineman or firefighter from an electrical fire that occurs while working within a manhole. The device dispenses a non-conductive amount of fire suppressant material having fire suppression and extinguishing properties without creating an electrically conductive environment. The admixture preferably can cling to walls, ladders, clothing and skin.

CROSS-REFERENCE TO RELATED APPLICATIONS A concurrently filed application entitled "Solid State Microwave Power Source For Use In An Electrodeless Light Source" bears Ser. No. 705,324, is assigned to the same assignee herein, and is filed in the name of Robert J. Regan, Paul O. Haugsjaa and William H. McNeill. Also, a concurrently filed application entitled "Continuous Automatic Starting Assist Circuit For A Microwave Powered Electrodeless Lamp" bears Ser. No. 705,328, is assigned to the same assignee herein, and is filed in the name of Robert J. Regan, Paul O. Haugsjaa and William H. McNeill. BACKGROUND OF THE INVENTION The present invention relates to microwave excited electrodeless light sources and, more specifically, to an automatic starting control circuit for an electrodeless lamp powered by a solid state microwave source. There has recently been developed a light source in which an electrodeless lamp is disposed at the ends of inner and outer conductors of a fixture in which the lamp forms a termination load for microwave power supplied at the other end of the conductors. There have also been developed various types of starting assist devices for this type of light source. The need for a starting assist is due to the high impedance mismatch between the lamp in the off state and the output impedance of the power source which results in a low percentage of the forward directed power being absorbed by the lamp. In one starting scheme, the fixture is made to be in a condition of resonance at starting to increase the power absorbed by the lamp. In another scheme, a UV light source is used to supply a flux of UV photons to the lamp. Both schemes have functioned satisfactorily in providing a starting assist. In both starting assist devices, the operator must manually disconnect the devices after the lamp is started. There exists a need for automatic connecting and decoupling of these devices if the electrodeless light source is to have enhanced versatility. It has also been found that a solid state microwave power source can not tolerate running into large impedance mismatches such as occur when the source is coupled to a lamp in the off state. SUMMARY OF THE INVENTION It is an object of the invention to provide a reliable starting control circuit for a microwave powered electrodeless lamp in which a starting assist device is automatically coupled into and decoupled out of the light source while also automatically protecting the power source from damage due to large impedance mismatches. According to the invention, there is provided a control circuit for use in an electrodeless light source having a source of power at a microwave frequency, an electrodeless lamp having an envelope made of a light-transmitting material and a volatile fill material emitting light upon breakdown and excitation and a termination fixture having an inner conductor and an outer conductor disposed around the inner conductor, the conductors having first ends associated with the lamp and second ends coupled to the source so that microwave power terminates at the lamp to cause breakdown and excitation of the fill material. Accordingly, the source includes a dc power source and a microwave power source receiving the dc power for providing microwave power in an amount related to the amount of dc power received by the dc power source, the output of the microwave power source being coupled to the inner and outer conductors. A switch device is provided for controlling the application of dc power to the microwave power source. A UV producing light source is disposed near the lamp and coupled in series between the the dc power source and the microwave power source to emit UV light upon activation of the switch device to assist in starting the lamp. The UV source upon emission of light decreases the amount of dc power coupled to the microwave power source to reduce the output as the lamp is started. A device responsive to a preselected amount of heat from the UV source provides a shunt path for the dc power to bypass the UV source and thereby to provide maximum dc power to the microwave power source. In another aspect, a capacitive impedance device is adapted to be coupled across the conductors at the second end of the fixture to create a resonant condition in the fixture as microwave power is first applied to the lamp. The heat responsive device decouples the capacitive impedance means after the lamp is started. Preferably, the heat responsive device includes a switch having a bimetallic element electrically coupled at a first end to a first side of the UV source, and a first contact electrically coupled to a second side of the UV source. A second end of the bimetallic element moves into contact with the first contact in response to heat to form a shunt path for the dc current through the bimetallic element around the UV source. BRIEF DESCRIPTION OF THE DRAWING In the drawing: The sole FIGURE is a diagram illustrating the principle components according to the present invention. DESCRIPTION OF PREFERRED EMBODIMENT In an exemplary embodiment of the present invention, as shown in the FIGURE, there is provided an electrodeless light source represented generally by the reference numeral 10. The source 10 has a source of power represented generally by the reference numeral 12 at a microwave frequency. As used herein, the term "microwave frequency" is intended to include frequencies within the range of 10 MHz to 300 GHz. An electrodeless lamp 14 is provided and has an envelope made of a light-transmitting material, such as quartz, and a volatile fill material emitting light upon breakdown and excitation. A termination fixture represented by the reference numeral 16 has an inner conductor 18 and an outer conductor 20 disposed around the inner conductor 18. The conductors 18 and 20 have first ends 22 and 24, respectively, at which the lamp 14 is disposed and second ends 26 and 28, respectively, which are coupled to the source 12 of microwave power. A transparent dome 23 encloses the second end 24 of the outer conductor. This dome includes a metallic mesh which acts as a shield. Accordingly, the microwave power is absorbed by the lamp 14 to cause breakdown and excitation of the fill material. According to the invention, a starting control circuit is provided for assisting in the starting of the lamp 14. The source 12 includes a dc power source, which in the embodiment includes an ac source 30, such as a source of power at 60 Hz, and an ac to dc converter 32 for converting the ac power into a dc voltage across output terminals 34 and 36 of the converter 32. The dc power is coupled to a microwave power source 38 via a switch 40. The microwave power source 38 provides an amount of microwave power which is related to the amount of dc power received by the dc power source. The source 38 preferably includes a solid microwave oscillator and a solid state microwave amplifier. Additional details of one suitable power source may be found in the previously mentioned patent application entitled "Solid State Microwave Power Source For Use In An Electrodeless Light Source." The source described in this application includes an oscillator in which a transistor is the active element of a class "C" modified Colpitts type of common base oscillator, a transistorized class "C" power amplifier and an impedance matching circuit utilizing microstrip elements coupled between the output of the amplifier and the first ends 26 and 28 of the fixture 16 for providing an acceptable impedance transformation from the fixture to the collector of the power transistor and for providing a sufficient amount of power to the lamp during the starting mode. The output of the microwave power source 38 is coupled via a transmission line 42, such as a microstrip, to the inner and outer conductors 18 and 20. A UV light source 44 is disposed near the lamp 14 and is coupled in series between the dc power source 32 and the microwave power source 38 to assist in starting the lamp 14. The UV source upon the emission of light decreases the amount of dc power coupled to the microwave power source to reduce the power output as the lamp is started. In the FIGURE the UV source is shown as being displaced from the lamp 14 only for simplification of illustrating the features of the invention. In actual practice, the UV source is located either within the fixture near the first ends 22 and 24 of the conductors or outside the fixture and adjacent the transparent dome 23. A device represented generally by the reference numeral 46 is responsive to heat from the UV source and provides a shunt path for the dc power to bypass the UV source after the lamp is started. This causes maximum power from the converter 32 to be applied to the microwave power source 38. A reactive impedance device, such as the capacitor 50, is adapted to be coupled across the conductors 18 and 20 near the second ends 26 and 28 to create a resonant condition in the fixture 16 as microwave power is first applied to the lamp. Given the impedance of the lamp at starting, one skilled in the art may determine the required length measured along the conductor 18 separating the lamp 14 and the capacitor 50 and the required reactive impedance of the capacitor to achieve a condition of resonance. According to the invention, the heat responsive device 46 includes the capability for decoupling the capacitor 50 after the lamp is started. The heat responsive device 46 includes a switch having a bimetallic element 52 electrically coupled at a first end 55 to a first side 56 of the UV source 44 and a first contact 58 electrically coupled to a second side 60 of the UV source 44. The second end 62 of the bimetallic element 52 moves into contact with the first contact 58 in response to heat to form the shunt path for the dc current through the bimetallic element 52 and around the UV source 44. The capacitive impedance is coupled at one side 64 to the outer conductor 20 and at the other side 66 to the side 55 of the bimetallic element 52. A second contact 68 is electrically coupled to the inner conductor 18. The bimetallic element 52 is positioned such that the second end 62 of the bimetallic element 52 is in contact with the second contact 68 prior to movement of the bimetallic element due to heat. This permits the capacitor 50 to be coupled across the conductors 18 and 20 for starting. In operation, the second end 62 of the element 52 moves away from the second contact 68 in response to heat to decouple the capacitor 50 after the lamp is started. In the embodiment, the bimetallic element 52 has a first strip of conductive material made out of a nickel alloy having a low temperature coefficient and a second strip of conductive material made out of a nickel-chrome steel alloy having a higher temperature coefficient. In operation, the UV source in series with the microwave power source 38 reduces the voltage on the source 38 so that its power output is less than the full voltage value. This reduced power is fed via the transmission line 42 to the fixture 16. With the combination of the UV and the resonant condition brought about by the starting capacitor, this low power level is sufficient to start the lamp. With the low applied dc voltage, the microwave power source can withstand the mismatches occurring during the lamp warm-up. Some predetermined length of time after the microwave lamp is started, the heat generated by the UV source together with the heat generated in the bimetallic element itself due to absorption of microwave power, cause the bimetallic element 52 to bend downwardly thereby closing the lower contacts. This shunts out the UV source and applies full dc voltage to the source, causing it to produce full power. It can safely do this at this point because the microwave lamp is fully warmed-up and presents a matched load to the source. With the lower contacts closed, the bimetallic element carries the dc current. This heats the bimetallic element, helping to keep the lower contacts closed. Heat from the microwave lamp also tends to heat the bimetallic element. When the on-off switch 40 is open, the bimetallic element relaxes as it cools so that the upper contacts are closed and the system is in the ready-to-start mode. Thus, the major advantages according to the present invention are that there is provided a UV source for the lamp, a build-up of the microwave fields in the termination fixture by way of resonance, impedance matching the fixture to the source in the lamp-off condition and switching of the microwave power source from low power at starting to higher power after breakdown occurs in the lamp. These functions are accomplished automatically since once the on-off switch 40 is turned on, the system operates entirely by itself. The embodiment of the present invention is intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications of it without departing from the spirit and scope of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined by the appended claims.

A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the dc supply for a microwave power source for the lamp so that a reduced dc voltage is supplied to the microwave power source at lamp starting. At staring, a capacitive impedance element is coupled across the inner and outer conductors of the fixture to provide an additional starting assist by creating a condition of resonance in the fixture. A heat responsive bimetallic switch element associated with both the capacitor and the UV source automatically shorts out the UV source and decouples the capacitor after the lamp has started thereby permitting full dc power to the microwave power source during the operating condition of the lamp.

This is a continuation of application Ser. No. 433,838 filed Jan. 15, 1974, now abandoned. BACKGROUND OF THE INVENTION The invention relates to cascade drive systems which are commonly used in processes that deal with continuous lengths of material such as film, wire, paper, fabric, etc. In particular, it relates to a method of creating a cascade drive system using hydraulic components which are arranged in a series flow circuit in such a way that adjustment of the speed of any output shaft proportionately and synchronously adjusts the speed of all subsequent output shafts in the system. Present methods of achieving such cascade drive systems are by use of electronic control of DC motors in what are called tach-follower systems, and by placing mechanical speed variators between adjacent stages of a drive system. However, these methods create certain distinct disadvantages. In this regard, an electronic drive system involves considerable cost, bulky size, and the necessity to incorporate regenerative drives on stages that handle over-hauling loads. That is, loads that actually add power back to the drive system because of energy received from the processed material. Although the cost of mechanical speed variator drive systems is comparatively low, speed regulation achieved is relatively poor. Also, mechanical speed variators place stringent requirements on relative location of the various stages of the drive system, since all power must be transferred by chains, belts, gears, or the like. Hence, for efficiency and adaptability, a cascade drive system is needed which is low in cost, reasonable in size, flexible in arrangement, and can transmit relatively large quantities of power with good speed and ratio regulation. It is an object of this invention to provide a cascade drive system for efficiently regulating speeds and speed ratios throughout the system. It is another object to provide a cascade drive system capable of regeneration of power from over-hauling loads. It is a further object to provide a cascade drive system with a flexible spatial relationship between the various stages of the drive system. It is yet another object to provide a cascade drive system at a fractional cost of an equivalent electronic system, while maintaining approximately equal control features. Still another object is to provide a cascade drive system with relatively small components that are capable of transmitting large quantities of power. SUMMARY OF THE INVENTION In accordance with principles of this invention, the objects as set forth are attained by providing a cascade drive system using hydraulic components arranged in a series flow circuit. The system includes an electric motor-powered hydraulic pump which in turn drives a plurality of fixed displacement hydraulic motors in series. Each of these fixed displacement motors drives one stage of a multi-stage process. Coupled directly to the fixed displacement motors are individual variable displacement motors. The speed ratio between adjacent stages is controllable by adjusting the setting of an associated variable displacement motor which diverts a certain percentage of incoming flow to the corresponding fixed displacement motor from the preceding stage. Such a diversion synchronously changes the line speed of all subsequent stages and alters the speed ratio between the adjusted stage and the preceding stage. Overall line speed is controlled by varying the displacement of the variable displacement pump. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is schematic drawing illustrating an arrangement of components whereby a forward cascade system is achieved. FIG. 2 is schematic drawing showing an arrangement of components, oppositely oriented from FIG. 1, whereby a backward cascade system is achieved. FIG. 3 is a schematic drawing in which the components are arranged to achieve a closed loop, combination, backward and forward cascade system. FIG. 4 is a schematic drawing representing a somewhat different arrangement of components in which a variable speed motor is not directly coupled to a fixed speed drive motor on each stage. FIGS. 5, 6, and 7 are schematic drawings illustrating additional arrangements of components. DESCRIPTION OF PREFERRED EMBODIMENTS The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings in which like series of reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed on illustrating principles of the invention. Referring to elements of the invention as embodied in the drawings, FIG. 1 schematically represents a hydraulic cascade drive system with the various hydraulic components arranged to achieve a forward cascade drive system. The system comprises an electric motor 10 which mechanically drives a variable displacement hydraulic pump 12, which in turn hydraulically drives hydraulic motors 13a, 13b, 13c, and 13d in series. These motors are fixed displacement motors; each of which mechanically drives an output shaft for one stage of a four stage process. Variable displacment motors, 14b, 14c and 14d are mechanically coupled directly to the fixed displacement motors 13b, 13c and 13d respectively. Following the flow pattern of the drawing, hydraulic fluid passing through the fixed displacement motor on one stage subsequently must pass through the motor-set of the next stage. This fluid is selectively apportioned, however, between the fixed and variable displacement motors 13 and 14. Hence, the speed ratio between the outputs of adjacent stages is selectively controllable by adjusting the setting of the adjacent downstream variable displacement motor which diverts a certain percentage of the incoming flow from the preceding stage. This diversion of fluid from the series flow circuit reduces the quantity of fluid flow through all subsequent stages. Accordingly, the line speed of all subsequent stages is synchronously changed, at the same time that the speed ratio between the two adjacent stages is changed. For example, increasing the output of variable displacement motor 14b decreases the output speed ratio between stage A and stage B (i.e. the speed of stage B divided by speed of stage A) and synchronously reduces the output shaft speed of stages B, C and D. The overall line speed also can be controlled by varying the displacement of the main variable displacement pump 12. By increasing the flow from this pump, all stages of the process are proportionally increased in speed. Conversely, decreasing the displacement of pump 12 reduces the fluid flowing through the total series circuit, thereby proportionally reducing the speed of all outputs of the total system. A great advantage of the component arrangement of the above system is that all fluid that is diverted through the variable displacement motors and the fluid pressure differential thereacross actually helps drive the load on the respective stage. Therefore, there is no loss in power or energy due to this diverted flow, as commonly occurs in other hydraulic systems that divert flow back to a reservoir and incur energy losses through the use of pressure relief valves or the like. In other words, the above described cascade drive system with variable displacement motors connected to fixed displacement motors obviates the loss of energy and power due to pressure drops across conventionally employed pressure control valves and flow control valves. The system of the invention is totally regenerative in the event of over-hauling loads on the respective stages. That is, an over-hauling load actually tends to be retarded by the related fixed displacement motor, thereby causing the motor to act as a pump to increase the system pressure whereby the energy from the over-hauling load is reclaimed. Thus, the power is taken out of the load, and overspeed of the related output shaft is prevented. The absence of energy and power losses as described above, and the ability of the system to be regenerative to reclaim energy from the load, minimizes heat build up in the system fluid and allows the use of much smaller prime movers. The above described forward cascade system is used in processing systems where it is desired to hold the input speed of the processed material essentially constant. Any variation from this desired input speed can be adjusted by changing the output of pump 12 without there being any undesired change in the speed ratios between successive stages. The overall objective of such systems, however, is to selectively vary the ratios within the system so that only output speed and not the input speed is changed. Other processes require changes of the input speed without changing the output speed. This type of system, designated a backward cascade drive system, is illustrated by the component arrangement of FIG. 2. The operational mode of this system is the reversal of the forward cascade system illustrated in FIG. 1. In this arrangement, speed ratio changes within the system cause preceding stages to change line speed, rather than permit line speed to be altered in subsequent stages as in the forward cascade drive system. In FIG. 2 the processed material still moves in the same direction as in FIG. 1 -- from Stage A through Stage D -- but motor 20 causes the main variable displacement pump 22 to maintain the shaft speed of output stage D substantially constant while the ratios and speeds of input stages A, B, and C can be selectively varied by adjusting the outputs of variable displacement hydraulic motors 24a, 24b, and 24c respectively. Utilizing the preceding principles, various other drive configurations also are possible. Such an alternate system is depicted in FIG. 3. In that embodiment, the processed material is still moved in the same direction (from Stage A toward Stage D), but it is desired that the interior stage be maintained at a substantially constant speed rather than either input stage A (as in FIG. 1) or output stage D (as in FIG. 2). In FIG. 3 it is stage C that is maintained substantially constant by controlling the output of variable displacement hydraulic pump 32, while the speeds and ratios of the other stages A, B, and D can be varied by adjusting the amount of fluid that bypasses motors 33 through the mechanically coupled variable displacement hydraulic motors 34A, 34B, and 34D. The FIG. 3 system is a backward-type cascade system up to stage C and a forward-type cascade system after stage C. Stage C is a master drive or master stage. FIG. 3 also illustrates a closed loop system that returns all fluid to the inlet of the main variable displacement pump 32 without a reservoir as is used in open loop systems. Any of the other systems described can also be arranged for a closed loop system, if desired. Another embodiment of the invention is illustrated in FIG. 4. In this system, rather than mechanically coupling the variable displacement hydraulic motors directly to the fixed displacement hydraulic motors 43 in respective stages, the variable displacement hydraulic motors 44 are mechanically coupled to corresponding supplemental fixed displacement hydraulic motors 45 which are hydraulically coupled in series flow to the main fixed displacement motors 43. In this manner ratio-flow control is obtained between the various stages. This two-motor combination for ratio flow control is free-wheeling, because the motors are not directly coupled to the load. The ratio flow control has the capability of splitting flow from a preceding stage into any desired ratio of fluid reverted back to the reservoir or on to the next stage. Inclusively, this system also has the ability to be regenerative. It can reclaim energy out of over-hauling loads and convert it to pressure back into the drive system. Also, pressure energy of the fluid that is being shunted back to the reservoir is recovered. Just as in the system described above and illustrated in FIG. 1, this alternate arrangement of FIG. 4 can also be rearranged to operate as a backward cascade system, or a combination backward-forward cascade system, or it can be made into a branched cascade system where the output of one of the main fixed displacement motors 43 is delivered to two of the two-motor sets 44-45. Another embodiment shown in FIG. 5, illustrates a "shunt-pump" arrangement wherein one or more of the variable displacement motors such as 14 in FIG. 1 is replaced by a variable displacement pump 56. This variable displacement pump 56 is mechanically coupled to the fixed displacement motor 53 and also adds fluid to the motor's input rather than subtracting the flow as in the "shunting-motor" arrangements of FIGS. 1, 2, 3, and 4. This particular method of speed-ratio control offers the advantage of maintaining high flow rates in later stages. The maintenance of these later-stage high flow rates is sometimes difficult to achieve in multi-stage cascade systems. This shunting-pump arrangement, therefore, has particular utility when used in combination with shunting-motor arrangements to maintain fluid flow at desirable high levels throughout complex systems. Illustrated in FIG. 6 is a further embodiment using a variable pump-motor 66 which can be adjusted from full pump displacement through zero to full motor displacement in a reverse fluid flow direction while unidirectionally rotating the shaft of its associated motor 63 for operation in either mode. FIG. 7 illustrates yet another embodiment which employs a transmission such as geared mechanical connections 77 between the fixed displacement hydraulic motors 73 and the variable displacement hydraulic motors 74. These transmission sections 77 provide additional flexibility of selection of speed ratios between adjacent stages. This arrangement has the effect of multiplying (or dividing) the relative displacement of the variable displacement motors 74 (or pumps in the case where such gear connections are employed in the FIG. 5 or FIG. 6 embodiments.) While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various alterations in form and detail may be made therein without departing from the spirit and scope of the invention. For example, other relatively noncompressible matter such as particulate solids can be used and additional arrangements or modifications of the forward, backward, or combined systems described can be made without departing from the overall concept. Further, many options can be added to the basic system using standard components such as direction control and relief valves. Options such as clutching, braking, reversing, closed loop operation, free-wheeling, torque limiting, power servoing, and others can be readily achieved in accordance with common practice to fit the many applications in which cascade drive systems are used.

A cascade drive system is disclosed for use in processes that deal with continuous lengths of material such as film, wire, paper, fabric, etc. The system includes a plurality of stages holding fixed speed ratios to each other; and uses hydraulic components arranged in a series flow circuit, in such a way that the line speed may be synchronously increased or decreased and individual ratios between adjacent stages may be changed.

[0001] This application has the benefit of Provisional Application No. 60/723,618 filed Oct. 22, 2005. FIELD OF THE INVENTION [0002] In the underwater diving sport/industry aka SCUBA Diving, there is a requirement for the use of a buoyancy compensating device, particularly when the diver is wearing an environmental or exposure suit, either a wetsuit or drysuit or the like and carrying one or more tanks of compressed air. Neutral buoyancy of the diver and its equipment is first obtained at sea level. After a diver descends a few feet below sea level, neutral buoyancy is lost and the diver becomes negatively buoyant due to the increase of atmospheric pressure causing compression of the diver's body, equipment and any suit or protection device he is carrying. A relatively recent development of the past few decades has been an inflatable device which serves the purpose of adjustably compensating for the weight of the diver and the diver'equipment. This equipment has as its principal purpose to permit the diver to achieve neutral buoyancy at any depth and to assist the diver to selectively achieve levels of either positive or negative buoyancy as desired. In this regard, a commonly used device has developed in the form of a vest known as a buoyancy compensation device aka a BCD which the diver wears and which is capable of inflation and deflation as desired. DESCRIPTION OF THE PRIOR ART [0003] At the present development of the art, a BCD is made of an elastomeric material configured in the form of a jacket or a vest which has a waist or arm portion designed to surround a diver'waist, a front portion carrying a variety of straps and attachments and a backpack portion which carries mounting equipment upon which an air tank and related equipment are affixed. The vest is composed of one or more air chambers or pockets which are inflatable compartments situated either in the front portion of the vest, the arms and/or as a bladder on the back of the vest surrounding the backpack and air tank. A typical BCD in addition to carrying the mounting plate on the backpack for the air tank, accommodates the carrying of numerous other equipment attachments, such as the first stage pressure compensator affixed to the outlet of the air tank, various air hoses and/or other communication devices to provide the diver with information concerning the conditions of his equipment, and of his dive. In addition, some BCD's carry or are provided with attachments to carry detachable lead weights to offset the positively buoyant effect of the air of the tank and the positively buoyant effect of a wetsuit. In other situations, instead of part of a BCD vest, a diver may wear a separate weight belt which consists of a belt to which are attached a number of lead weights. The BCD vest configuration also includes shoulder straps and typically a front closing waist or belt fastener for ease of securing the buoyancy compensation device and for carrying the various equipment mentioned herein. [0004] As may be anticipated, there is a need to match body shapes and sizes to a buoyancy compensation vest. A loose fitting vest reduces performance and control by the diver. A tight fitting vest could be considered a safety hazard due to the possibility of respiratory restrictions should the vest become over inflated. It has been the custom of the industry to provide, as in the garment industry a number of size or ranges of sizes from extra small, small, medium, large, and extra large, and occasionally sizes in XXS and XXXL as well. It has long been a desire in the industry to provide a universally adjustable buoyancy compensation vest. The reasons are financial and administrative. Given the need for a properly fitting buoyancy compensator vest, it has been typical to have the numerous sizes mentioned. For the manufacturer, this presents a financial dilemma and at the consumer level causes higher costs and lower usage rates. Equipment rental shops are required to carry a wide range of sizes in order to accommodate customers and dive boat operators and dive shop suppliers likewise must carry a wide inventory of sizes to accommodate their customers. A similar scenario presents itself where friends and families wish to share and/or pass along their equipment to other members or with dive teams such as the military and Coast Guard, fire departments and search and rescue teams. The same is true for young divers who have not yet achieved full adult growth size and must either rent or sell and resell equipment of different sizes over the period of time of their body growth. In view of this stated need, a number of solutions have been proposed. [0005] U.S. Pat. No. 5,346,419 issued to Karl Kaiser (Kaiser '419) for a buoyancy compensator device with backpack and adjustable harness. The Kaiser device is an example of many similar buoyancy compensators which have sought to solve the problem of different waist or body girth sizes by providing a form of cummerbund or waistband. Kaiser '419 discloses a torso band having two adjustable elastic connection bands which connect at their distal extremities by means of a hook and pile fastener arrangement and the posterior portions of these bands are securely fastened to the inside wall of the buoyancy compensator body by adjustable buckle devices. By adjusting the buckle connections, the length of one or both of the torso bands can be lengthened or shortened to thereby adjust the vest to accommodate the girth of the diver. [0006] U.S. Pat. No. 5,662,433 issued to Scott P. Seligman similarly discloses a waist or girth adjustable BCD. In this reference, the waist size is incrementally adjusted by means of pins affixed to the interior of the back panel of the vest. The pins are fitted into one of several slots formed on the sides of each of the two waistbands. The two waistbands join together in the front again in a cummerbund fashion by overlapping hook and pile fasteners. In this manner, this reference teaches a degree of waist size or girth adjustment. [0007] U.S. Pat. No. 6,881,011 issued to Robert Manuel Carmichael similarly seeks to provide for an adjustment of the waist size. This reference teaches that this adjustment can be accomplished by utilizing a three part construction consisting of two side belts that pass through a wire-loop fixture and return against the inside of the belt which is secured at its outer ends by hook and pile fastener. The back looped portion of the belt is secured and locked in place by the compression created by wearing the device. [0008] In U.S. Pat. Nos. 5,451,121 and 5,562,513 similarly teach the provision of buoyancy compensation device having adjustable or variable adjustments for waist size by varying the length of a waistband. [0009] Each of these designs suffer the deficiency that the methodology for providing an adjustable waist size can provide only a limited range of adjustment. This is due in significant part to the fact that these vests are made of heavy fabric and are thus somewhat bulky and inflexible. A vest well fitted to an adult male who wears, for example, a size 46 jacket, could not be made to properly fit an adult female who typically wears a size 8 dress size by employing the waistband adjustment schemes of the prior art. The range of adjustment is not sufficient. And while most of these references also teach the provision of an elastic section in the waist belt or waist band, an elastic section serves only to maintain a pre-adjusted securement to compensate for compression changes in body size as a result of the depth at which a diver is located at any one time. The elastic sections in these belts as taught by the prior art do not provide a means of adjusting the girth of the device. [0010] In spite of the development of the devices set forth in the prior art and other similar devices, it remains a requirement of equipment providers and manufacturers to provide buoyancy compensation vests in a wide range of sizes from extra small to extra large. This is so because of the requirement for a very good fit between the diver and his buoyancy compensation vest. [0011] It is an object of the present invention to provide a buoyancy compensation device in the form of a vest which is universally adjustable about of the waist of the diver's body and which can vary in girth or diameter from extra small to extra extra large. [0012] It is a further object of the present invention to provide a buoyancy compensation device which is continuously variable and adjustable to accommodate the different girth sizes of a diver. [0013] Yet a specific object of the present invention is to provide a buoyancy compensation device in which the waist can be adjusted by adjusting the size of the inflatable arms of the device. [0014] It is a further object of the present invention to provide a buoyancy compensation device which can accommodate different body sizes of divers independently of adjustment of the waist band or cummerbund attachments typical of prior art devices. SUMMARY OF THE INVENTION [0015] In summary, this invention is directed to a buoyancy compensation (sometimes also called “compensator”) device (BCD) having a typical shell consisting of a body portion having an inside wall and an outside wall forming an inflatable member with a typical backpack portion which includes a securing band adapted for securing an airtank to the backpack. The BCD is in the form of a vest consisting of a back portion and lateral arms which are intended to be secured at the waist of the wearer and affixed in the front in the typical manner such as by buckles, snap tabs or hook and pile fasteners. There are various ways set forth in the prior art for affixing the terminal ends of the arms together in the front of the wearer. There are two variations of the typical vest, one in which the shell of the vest is made of a heavy canvas-like material which has been impregnated with urethane so that it may be inflated and will hold air under pressure against leakage. In another basic embodiment, the shell is fitted to accommodate internal bladders formed of sealable urethane. These bladders are inserted inside the arms and/or the back portions of the vest and are communicated to a source of low pressure air for inflation. In that embodiment, it is the internal bladders which carry the air to inflate the vest rather than the shell of the vest as in the first embodiment. [0016] The invention involves a mechanism for varying the reach of the arms by selectively collapsing the material in the arms so that when the arms are joined together in the front of the wearer, they will fit a wide range of body sizes or waist sizes. This mechanism includes a strap affixed through a intermediate pouch to an additional strap or straps inside the enclosure of the arms so that they can be pulled inwardly or let outwardly to adjust to a desired waist size. The retraction of the strap pulls the shell of the arm by applying tension on the inner surface of the shell, collapsing the material of the shell. Appropriate supporting baffles situated in the enclosure of the arms or in the bladders inserted in the enclosure of the arms, avoid lateral enlargement of the arms upon inflation. Subsequent inflation of the adjusted arms smoothes out the collapsed material of the arms and achieves a smooth adjusted size for each of the arms so that precise adjustment to each individual wearer can be achieved. This adjustment system is designed to promote a secure attachment to the wearer of the BCD and a precise adjustment of size to the particular body configuration of almost any wearer. Thus at the water'surface or at significant depths, the vest will be form fitting and comfortable for the diver. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is a front plan view of the buoyancy compensator device of the present invention. [0018] FIG. 2 is a partial perspective view of one of the arms of the buoyancy compensator device showing a first embodiment of the present invention. [0019] FIGS. 3A and 3B are partial sectional views taken along line 3 - 3 of FIG. 2 . FIG. 3A demonstrates the intermediate pouch when the arm is in an extended position and FIG. 3B is a cross-sectional view showing the intermediate pouch when the adjustment mechanism is fully retracted. [0020] FIG. 4 is a partial perspective view of an arm of the BCD in a retracted configuration prior to inflation thereof. [0021] FIG. 5 is a perspective plan view of the buoyancy compensator device of the present invention after the arms have been retracted and the vest has been inflated. [0022] FIG. 6 is a partial perspective view of the buoyancy compensator device employing features of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0023] FIG. 1 discloses a dive vest laid out in a planar fashion showing the arms 10 and the back portion 10 a . This is a type of BCD which is termed “back inflatable”, which also has inflatable arms. Shown in dotted lines not relevant to the present invention, are the overpressure relief valve (OP) and the entry valve (RE), which is the connection to the low pressure portion of the dive system which provides low-pressure air to inflate the vest. Relief valve (RE) is usually also a selective dump valve. Shown in dotted lines is an illustration of the range of adjustment afforded the arms, as demonstrated by the lateral arrows, indicating the relocation of the ends and/or enlargement of the arms by adjustment. [0024] FIG. 2 is a partial sectional view of one of the arms 10 showing the adjustment mechanism of a first embodiment of the present invention. In this embodiment, the shell of vest arm 10 includes upper and lower panels 11 and 12 which are sealably attached around the periphery at 13 so as to provide an airtight enclosure. As indicated by the arrows in FIG. 1 , the adjustment mechanism of the present invention comprises a structure for pulling in the arms 10 in order to decrease the girth of the vest. In this regard, reference to FIG. 2 discloses in greater detail a first embodiment of a mechanism for pulling in or conversely letting out the length of the arms. This mechanism consists primarily of strap which extends from outside the shell into the enclosure of arm 10 through a first aperture 14 and through a second aperture 16 in first baffle 17 . Strap 15 a is then formed into a Y or yoke having arms 18 and 19 . The extremities of arms 18 and 19 are welded to the upper panel 11 and lower panel 12 of arm 10 as indicated by the circular embossments at 20 and 21 , respectively. Baffle 17 is welded in a manner well-known in the industry to the upper and lower portions of arm 10 at 17 a and 17 b as shown in FIG. 2 . A second baffle 23 is similarly welded at upper and lower portions 23 a and 23 b. [0025] Strap 15 must be accessible at the exterior of inflatable arm 10 to set the adjustment in buckle 30 ; however, in order to most effectively collapse the size of arm 10 , strap 15 should be able to communicate with the interior enclosure of arm 10 to withdraw the upper and lower panels 11 and 12 . The problem is how to do this without leaking air from the enclosure, or conversely leaking water into the enclosure. This is accomplished by the intermediate pouch 27 . While a preferred embodiment of the invention employs the feature of affixing the adjustment strap in the interior of the enclosure, it is within the scope of this invention to alternatively affix the strap simply to an outer surface of the arm. It is believed that the concept of the present invention broadly encompasses the shortening of the inflatable shell portion of a vest as the means of obtaining a broad range of adjustment of the girth, as distinguished from the waistband approach. While an exteriorly mounted strap can accomplish this goal, a strap located on the outside of the shell of the vest may become snagged or entangled with other parts of the divers gear. For this and for cosmetic reasons, it is preferred that the strap be affixed inside the enclosure. [0026] FIG. 3A shows a sectional representation of the adjustable BCD and, in particular, shows greater detail of the intermediate pouch 27 . Pouch 27 has an aperture 14 a , which is welded to aperture 14 of top panel 11 . Pouch 27 is thus totally situated within the enclosure of the shell and, while aperture 14 is open to the outside atmosphere, pouch 27 is entirely sealed and in communication with the interior enclosure of arm 10 . Adjustment strap 15 extends through apertures 14 and 14 a . Adjustment strap 15 extends to the distal end of pouch 27 and is weldably fixed thereto at point 29 . Point 29 is in turn weldably affixed to an extension of strap 15 , i.e., strap 15 a , which extends through aperture 16 and then is divided into upper and lower yoke members 18 and 19 , which are respectively affixed by appropriate weldments 20 and 21 to the upper and lower surfaces of the arm 10 , specifically, the under-surfaces of panels 11 and 12 , respectively. [0027] FIGS. 3A and 3B provide a graphic representation of further features of the pouch 27 shown in FIG. 2 . The intermediate pouch 27 is made of quite flexible material. It is shown in FIG. 3A with the arm 10 in its most extended position. Reduction of the length of arm 10 from its most extended position is accomplished by pulling strap 15 to the left and fixing it with the buckle 30 . As strap 15 is pulled inwardly, the intermediate pouch 27 is pulled inwardly as well and collapses without compromising the sealed integrity of the interior enclosure of arm 10 . As strap 15 is pulled more and more inwardly, the weldment section 29 on pouch 27 can be pulled through apertures 14 , 14 a so as to achieve the maximum withdrawal and therefore foreshortening of arm 10 . It is contemplated that the range of movement of strap 15 from its outermost extension to its innermost withdrawal can be on the order of about twice the dimension between aperture 14 and weldment 29 , indicated at “X ” in FIG. 3A . If, for example, the pouch were constructed such that dimension “X ” were six (6) inches, adjustment of arm 10 could achieve a range of about twelve (12) inches. [0028] Referring now to FIG. 4 , it will be seen that upon a substantial withdrawal of strap 15 , the material of arm 10 becomes folded or crumpled in a seemingly unsuitable fashion in that, in particular, the area between the points of affixation of strap 15 a at weldment 20 collapses as strap 15 is pulled to the left, and even more so if weldment 29 is pulled through aperture 14 . It would thereupon seem that the inflatability of the adjusted vest is compromised; inasmuch as there is now a bulk of material still a part of arm 10 that has been foreshortened, collapsed and, accordingly, of questionable inflatable utility. However, because the arm and back portion of the BCD are an integral inflatable structure, the collapse of the material in arm 10 permits that material upon inflation to move into the back portion of the vest. The width of the arms do not increase laterally because baffles 17 and 22 limit lateral expansion of arm 10 , and further assist in urging the collapsed materials of arm 10 to migrate to other areas of the shell. FIG. 5 shows a fully inflated vest with the adjustment straps of both arms fully withdrawn to shorten the arms to the minimum. The vest fully inflates and the arms and the collapsed material are fully extended without increasing the width or diameter of the arms. The material of the foreshortened portions of panels 11 and 12 has moved elsewhere into the back portion of the vest so that when the vest is fully inflated, the arms as shown in FIG. 5 fully and smoothly inflate to form a competent and comfortable buoyancy control device. [0029] It is in particularly preferred embodiment of this invention to employ the features of the intermediate pouch 27 which comprises the means of communication between the interior of the inflated enclosure of arm 10 and the exterior or atmospheric side of the device. This collapsible pouch of material allows strap 15 to be fully withdrawn inwardly towards the posterior of the BCD until the strap 15 may be pulled through to the full extent of the length of the pouch. By this means, it is possible to construct an adult size BCD having a continuously variable waist size from what is commonly called in the garment industry as extra, extra large (XXXL) to extra small (XS). This permits a change in girth from typically 48″ to approximately 26″ in circumference. This is facilitated by the extreme flexibility of intermediate pouch 27 which can extend all the way from the position shown in FIG. 3A until it is pulled through aperture 14 for maximum withdrawal as shown in FIG. 3B . Second Embodiment of the Present Invention [0030] The second embodiment of the present invention accommodates the type of BCD vest wherein the shell does not provide the inflatable air retention pockets of the device, but rather separate bladders made of air impervious urethane material is used as the air container of the first instance. In this configuration, the material of the shell can be a lighter weight material, but may also be impregnated with urethane material so as to provide a secondary protection against leakage, if desired. FIG. 6 shows the present invention adapted to a dual bladder, or inner bladder version of BCD. Here arm 100 has upper and lower panels 110 and 111 sealably attached at the edges 113 to form an enclosure. This arm 100 is provided with zipper 114 to provide access to the interior of arm 100 for the insertion of bladder 115 . Bladder 115 is provided with interior baffles 116 and 117 , which limit lateral expansion of the bladder upon inflation similar to the function of baffles 17 and 22 in the single bladder embodiment. In the double bladder configuration, the retraction system is similar, in that an intermediate pouch 120 is employed, substantially like pouch 27 of the first embodiment. The adjustment strap 118 is coupled at one end to buckle 121 and extends through aperture 122 into the interior enclosure of pouch 120 . At the distal end of pouch 120 , strap 118 is welded at 123 . Another portion 124 of the adjustment strap is fixed in similar manner to an outer portion of pouch 120 immediately adjacent weldment 123 at the distal end of pouch 120 . In this embodiment, strap 124 extends into the enclosure, over the bladder 115 to an intermediate portion of the upper panel 110 of arm 100 and is welded to the interior panel as shown at weldment 125 . While FIG. 6 shows strap 124 attached to the upper panel 110 , it is equally contemplated to attach it to the lower portion 111 of arm 100 . Similarly, as related in the description of the single bladder version, it is contemplated that the strap here could be simply attached to an outside surface of the arm and accomplish the purpose of shortening the arm; however, as stated, this may not work as efficiently as the interior attachment. Furthermore, the cosmetics are not as aesthetically pleasing, and an exterior strap could become snared or entangled by the divers other equipment, and thus is not such an efficacious design as the interior attachment regime. [0031] In this embodiment, strap 118 functions in a similar way to that of strap 15 in that retracting or moving strap 118 to the left (in FIG. 6 ) pulls strap 124 to the left, pulling weldment 125 towards aperture 122 . Similar to what is shown in FIG. 3B , full retraction of the adjusting strap contemplates pulling the distal end of pouch 120 through its own aperture 122 . Full retraction of the adjustment strap 118 in the dual bladder version can be accomplished in a manner similar to that shown in FIG. 3B . Hence, in use, obviously prior to the full inflation of bladder 115 , strap 118 may be adjusted and held in place by buckle 121 while the continuous retraction of strap 118 achieves the proper waist adjustment for the vest. [0032] It is contemplated that elastic portions in straps 118 or 15 may also be employed to permit slight size variations in the pre-adjusted sizing of the arms. Elastic portions accommodate changes in body size due to compression. The vest maintains the pre-adjusted sizing accomplished prior to immersion in the water, thereby accommodating changes in the body of the diver and of his equipment at greater depths below sea level, while maintaining the same pre-fit and adjusted sizing of the vest made prior to diving. This maintains a good fit of the vest on the diver throughout the dive. [0033] The second embodiment can thus provide in a manner similar to that of the first embodiment a means of adjusting the size of the arm 100 so as to accommodate a range of sizes continuously adjustable from a very small waist size typically of about 26 inches in diameter to approximately 48 inches in circumference or more. The range of adjustment provided strap 118 can provide a continuous and finely adjustable variation for the size of arm 10 to accommodate sizes anywhere from extra, extra large to extra small, speaking of garment sizes, so that the buoyancy compensator device may be worn by different people of substantially different size and shape and yet provide a proper and snug fit that is neither too loose nor too tight. [0034] While particular embodiments and preferred designs have been shown and described herein, it is contemplated that various modifications and/or variations of the invention are contemplated and can be resorted to by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.

A buoyancy compensator vest for providing adjustable buoyancy at various underwater depths by having a back portion for supporting an air tank and an air bladder for inflating and deflating, a portion of the air bladder of which is situated in the arms which surround the waist of the wearer. The improvement of an adjustment strap which can provide continuous variation within limits, of the reach of each of the inflatable arms of the vest whereby the girth of the vest can be continuously and uniformly adjusted to accommodate a wide range of body sizes, in particular waist sizes.

FIELD OF THE INVENTION This invention relates to a set of brackets for constructing a wooden gate. BACKGROUND OF THE INVENTION Corner gate brackets can be used to frame right angle joints between structural members of a gate at each of four corners. Such gate brackets are meant to provide a reliable guide for the positioning of the structural members to assist the do-it-yourself handy man. In addition, corner gate brackets are meant to minimize or eliminate the distortion of the gate structure over time. Gate brackets are typically made of metal so as to resist bending and to ensure a rigid structure. Typically, a gate bracket comprises elongate flat metal members arranged in perpendicular relationship so as to guide the formation of a right angle between the pieces of structural lumber which are made to abut the elongate members. An example of such a system is disclosed in Boroviak, U.S. Pat. No. 6,896,244. Parallel elongate flat metal members may be provided in a spaced relationship for bracketing structural lumber on two opposed sides and to provide a perpendicular arrangement of such elongate members. Such a system is disclosed in Cosgrove, U.S. Design Pat. No. D410,835. In Cosgrove, each pair of parallel elongate flat metal members form a U-shape and the two U-shaped pairs are welded together to form the overall bracket. To provide structural rigidity for gate brackets, typically either a brace member is provided, as in Boroviak, or relatively thick metal members are provided, as in Cosgrove. In Boroviak, the diagonal brace member is welded to each of the perpendicular elongate metal members, which are in turn welded together at the intersection. It is an object of the present invention to provide a structural gate bracket that serves to effectively frame a right angle between structural pieces, such as 2×4 pieces of lumber, while maintaining the structural relationship of the joint, over time, and at the same time not providing undue weight to the gate bracket, avoiding overly thick metal elements or excessive welding. This and other objects of the invention will be better understood with reference to the detailed description of the invention which follows. SUMMARY OF THE INVENTION According to the invention, there is provided a web extending in a plane. A first pair of perpendicular elongate portions are provided normal to the plane of the web, preferably along two edges of the web. A second pair of perpendicular elongate portions are provided normal to the plane of the web in spaced parallel relationship to the first pair. In another aspect of the invention, each pair of elongate portions comprises flanges of said web. In a further aspect, an opening is provided in said web member between the first and second pairs of elongate portions. In a further aspect, the opening extends between a first pair of parallel first and second members and between a second pair of parallel first and second members thereby defining a substantially L-shaped opening. In another aspect, the invention comprises a web extending in perpendicular directions in a plane, said web including a first flange extending normal to said plane parallel to a first one of said directions, a second flange extending normal to said plane parallel to a second one of said directions in an end-to-end perpendicular, abutting relationship to said first flange. The web has an outer perimeter, an opening extending in generally perpendicular directions within said perimeter, a third flange normal to said plane along an edge of said opening and in spaced relationship to said first flange and a fourth flange normal to said plane along an edge of said opening and in spaced relationship to said second flange. In another aspect, the invention comprises a method of forming a gate bracket comprising: providing a web extending generally in perpendicular directions within a plane and having an opening within the perimeter thereof, said opening extending generally in said perpendicular directions; bending one edge of said web to provide a first flange normal to said plane; bending a second edge of said web to provide a second flange normal to said plane and abutting said first flange in a perpendicular relationship; bending a portion of said web that is adjacent to an edge of said opening to form a third flange normal to said plane; bending a portion of said web that is adjacent to an edge of said opening to provide a fourth flange normal to said plane and in perpendicular abutting relationship to said third flange. The foregoing was intended as a broad summary only and of only some of the aspects of the invention. It was not intended to define the limits or requirements of the invention. Other aspects of the invention will be appreciated by reference to the detailed description of the invention and to the claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by reference to the detailed description of the invention and to the drawings thereof in which: FIG. 1 is a front perspective view of a first embodiment of the invention; FIG. 2 is a rear perspective view of the first embodiment of the invention; FIG. 3 is a plan view of the first embodiment; FIG. 4 is a plan view of a web member, prior to bending, according to the method of the first embodiment; FIG. 5 is a front perspective view of a web member of FIG. 4 after the bending of the first and second flanges according to the method of the first embodiment; FIG. 6 is a rear perspective view of a second embodiment of the invention; and FIG. 7 is a front perspective view of a third embodiment of the invention; FIG. 8 is a front perspective view of a fourth embodiment of the invention; and FIG. 9 is a plan view of the fourth embodiment of the invention, prior to bending. DETAILED DESCRIPTION OF THE INVENTION Throughout the following description specific details are set out to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the present invention. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. Referring to FIGS. 1 , 2 and 3 the gate bracket of the first embodiment 10 includes a web 12 extending within a plane generally along two perpendicular directions 14 and 16 in a generally L-shaped configuration. Web 12 has a generally L-shaped opening 18 that extends in perpendicular directions parallel to directions 14 and 16 . Opening 18 is spaced inwardly from the perimeter 20 of the web 12 . A first flange 22 extends normal to the plane of the web 12 along a perimetral edge 24 of web 12 , parallel to direction 14 . A second flange 26 extends normal to the plane of the web 12 along a perimetral edge 28 of web 12 , parallel to direction 16 . First 22 and second 26 flanges are in abutting perpendicular relationship to one another. A third flange 30 extends normal to the plane of the web 12 along an edge 32 of opening 18 . Third flange 30 extends parallel to first flange 22 and in spaced relationship therewith. A fourth flange 34 extends normal to the plane of the web 12 along an edge 36 of opening 18 . Third 30 and fourth 34 flanges are in abutting perpendicular relationship to one another. The spacing between first 22 and third 30 flanges is selected so as to correspond to the dimensions of structural pieces (such as lumber, plastic or metal), to be used in the gate system, as is the spacing between second 26 and fourth 34 flanges. One end of each of the third and fourth flanges may optionally be further bent away from opening 18 as at 38 , 40 in order to provide additional structure rigidity to the flanges. A hinge 42 may be provided on selected brackets according to whether the bracket will be used on the hinge side of the gate to be constructed. One advantage of the first embodiment of the invention is that the entire structure, save for the attachment of a hinge, may be formed from a single flat sheet of materials, as will be described by reference to FIGS. 4 and 5 . There is first provided a web 12 as shown in FIG. 4 that extends generally in two perpendicular directions 14 and 16 . Web 12 is cut at 17 , 19 , 21 and 23 , with cut 19 being parallel to direction 14 and cut 21 being parallel to direction 16 . Each cut 17 , 19 , 21 , 23 is spaced inwardly from the edges of web 12 . A gap 15 is provided at the juncture cut lines 19 and 21 . An elongated rectangular portion 30 is bent from the plane of the web so as to be normal to it and an elongated rectangular portion 34 is bent from the plane of the web so as to be normal to it to form flanges 30 and 34 . Short end portions 29 , 31 of flanges 30 , 34 may then be bent along lines 33 , 35 so as to be normal to flanges 30 , 34 to provide structural rigidity to flanges 30 , 34 . An elongated rectangular portion 22 along edge 25 of web 12 is bent so as to form a flange 22 that is normal to the plane of the web 12 . An elongated rectangular portion 26 along edge 27 of web 12 is bent so as to form a flange 26 that is normal to the plane of the web 12 . Once bent, flanges 22 and 26 are in abutting perpendicular relationship and flanges 30 , 34 are in abutting perpendicular relationship, as seen in FIGS. 1 and 2 . As shown in a second embodiment 60 illustrated in FIG. 6 , the shape of the web 12 may be altered in area 68 , for example to increase rigidity, and the hinge 42 may not be provided on selected brackets. As shown in the third embodiment 70 shown in FIG. 7 , alternate embodiments of the invention do not require web 12 to extend into area 68 beyond flanges 30 and 40 . Optional piece 76 could be welded between flanges 30 and 40 to assist with the structural integrity of the bracket. A fourth embodiment 80 is shown in FIG. 8 in which a straight edge 86 can brace the portion between perpendicular structural members on a corner. Flanges 82 and 84 can be attached to the outside edges of structural members while flanges 88 and 90 can be attached to the inside edges. Flange 82 together with flange 88 and flange 84 together with flange 90 can firmly hold the structural members (such as 2×4 lumber pieces) of the corner of a gate in place. When folded in position, flanges 88 and 90 leave openings 92 and 94 in embodiment 80 . The edge along 86 can be reinforced by folding the edge over itself, as shown in FIGS. 8 and 9 . Further, a hole 96 may be provided, for example to reduce the overall material used and the weight of the embodiment. For versions of embodiment 80 used on the side of the gate to which a hinge should be attached, a hinge may be attached to one of flanges 82 and 84 , and preferably to flange 84 . As shown in FIG. 9 with reference to planar layout 98 , embodiment 80 can be made from a flat piece of unitary material, such as sheet metal. In a method of assembly of a gate or door, four brackets as described above, may be used in the construction of a gate. Two brackets placed on adjacent corners may have hinges, whereas the two other brackets may not have hinges. Structural pieces, such as lumber, plastic or metal members may be used in the assembly of the gate. Typically four structural pieces of lumber (or equivalent) will be used to create a gate frame in a square or rectangular formation. Gate face structural members, such as 2×4 pieces of lumber, can then be secured to the gate frame to complete the gate. As understood in the art, the face structural members could be attached to one side of the gate frame, on both sides, or having face structural members in an alternating pattern with structural members secured to opposing sides of the gate frame. Many other variations or additional features can be practiced in accordance with this invention. For example, a structural brace 66 could be added between flanges 30 and 34 . The structural brace would help maintain the structural integrity of the corner of the gate. The structural brace could be placed at any suitable angle, such as 45 degrees from each of flanges 30 and 34 . Portions 64 of web 12 could be punched out, cut out, or otherwise removed from the structure without departing from the scope of the invention. Cutting out portions 64 of web 12 could be of any desired shape and location and would reduce the amount of material, such as metal, and reduce the weight of the gate bracket. In certain embodiments, reinforcing lines 62 could be used to add structural integrity to the metal. Reinforcing lines 62 could be depressions formed on one side of the metal, with a corresponding protrusion on the opposite side of the metal. To maximize effectiveness of the reinforcing lines 62 , the lines may be linear. Reinforcing lines 62 could be added to web 12 or flanges 30 and 31 . It will be appreciated by those skilled in the art that the first and second embodiments have been described above in some detail but that certain modifications may be practiced without departing from the principles of the invention.

A gate bracket is formed of a planar web in which two rectangular portions along two edges of the web are bent to define a first pair of perpendicular flanges, and two other rectangular portions are bent from an inner portion of the web to form a second pair of perpendicular flanges. The flanges of the first pair are spaced from the flanges of the second pair by a distance corresponding to the dimensions of the structural members used to construct the gate. The invention provides a rigid bracket of simpler and lighter construction than prior art brackets.

BACKGROUND 1. Field of the Invention Gutter covering systems are known to prevent debris from entering into the open top end of a rain gutter. When debris accumulates within the body of a rain gutter in an amount great enough to cover the opening of a downspout-draining hole the draining of water from the rain gutter is impeded or completely stopped. This occurrence will cause the water to rise within the rain gutter and spill over it's uppermost front and rear portions. The purpose of a rain gutter: to divert water away from the structure and foundation of a home is thereby circumvented. 2. Prior Art The invention relates to the field of Gutter Anti-clogging Devices and particularly relates to screens with affixed fine filter membranes, and to devices that employ recessed wells or channels in which filter material may be inserted, affixed to gutters to prevent debris from impeding the desired drainage of water. Various gutter anti-clogging devices are known in the art and some are described in issued patents. U.S. Pat. No. 5,557,891 to Albracht teaches a gutter protection system for preventing entrance of debris into a rain gutter. Albracht teaches a gutter protection system to include a single continuous two sided well with angled sides and perforated bottom shelf 9 into which rainwater will flow and empty into the rain gutter below. The well is of a depth, which is capable of receiving a filter mesh material. However, attempts to insert or cover such open channels of “reverse-curve” devices with filter meshes or cloths is known to prevent rainwater from entering the water receiving channels. This occurrence exists because of the tendency of such membranes, (unsupported by a proper skeletal structure), to channel water, by means of water adhesion along the interconnected paths existing in the filter membranes (and in the enclosures they may be contained by or in), past the intended water-receiving channel and to the ground. This occurrence also exists because of the tendency of filter mediums of any present known design or structure to quickly waterproof or clog when inserted into such channels creating even greater channeling of rainwater forward into a spill past an underlying rain gutter. Filtering of such open, recessed, channels existing in Albracht's invention as well as in U.S. Pat. No. 5,010,696, to Knittel, U.S. Pat. No. 2,672,832 to Goetz, U.S. Pat. Nos. 5,459,350, & 5,181,350 to Meckstroth, U.S. Pat. No. 5,491,998 to Hansen, U.S. Pat. No. 4,757,649 to Vahldieck and in similar “reverse-curved” inventions that rely on “reverse-curved” surfaces channeling water into an open channel have been known to disallow entrance of rainwater into the water-receiving channels. Albracht's as well as previous and succeeding similar inventions have therefore notably avoided the utilization of filter insertions. What may appear as a logical anticipation by such inventions at first glance, (inserting of a filter mesh or material into the channel), has been shown to be undesirable and ineffective across a broad spectrum of filtering materials: Employing insertable filters into such inventions has not been found to be a simple matter of anticipation, or design choice of filter medium by those skilled in the arts. Rather, it has proved to be an ineffective option, with any known filter medium, when attempted in the field. Such attempts, in the field, have demonstrated that the filter mediums will eventually require manual cleaning. German Patent 5,905,961 teaches a gutter protection system for preventing the entrance of debris into a rain gutter. The German patent teaches a gutter protection system to include a single continuous two sided well 7 with angled sides and perforated bottom shelf which rainwater will flow and empty into the rain gutter below. The well is recessed beneath and between two solid lateral same plane shelves close to the front of the system for water passage near and nearly level with the front top lip of the gutter. The well is of a depth, which is capable of receiving a filter mesh material. However, for the reasons described in the preceding paragraphs, an ability to attach a medium to an invention, not specifically designed to utilize such a medium, may not result in an effective anticipation by an invention. Rather, the result may be a diminishing of the invention and its improvements as is the case in Albracht's U.S. Pat. No. 5,557,891, the German Patent, and similar inventions employing recessed wells or channels between adjoining planes or curvatures. U.S. Pat. No. 5,595,027 to Vail teaches a continuous opening 24A between the two top shelves. Vail teaches a gutter protection system having a single continuous well 25, the well having a depth allowing insertion and retention of filter mesh material 26 (a top portion of the filler mesh material capable of being fully exposed at the holes). Vail does teach a gutter protection system designed to incorporate an insertable filter material into a recessed well. However, Vail notably names and intends the filter medium to be a tangled mesh fiberglass five times the thickness of the invention body. This type of filtration medium, also claimed in U.S. Pat. No. 4,841,686 to Rees, and in prior art currently marketed as FLOW-FREE. TM. is known to trap and hold debris within itself which, by design, most filter mediums are intended to do, i.e.: trap and hold debris. Vail's invention does initially prevent some debris from entering an underlying rain gutter but gradually becomes ineffective at channeling water into a rain gutter due to the propensity of their claimed filter mediums to clog with debris. Though Vail's invention embodies an insertable filter, such filter is not readily accessible for cleaning when such cleaning is necessitated. The gutter cover must be removed and uplifted for cleaning and, the filter medium is not easily and readily inserted replaced into its longitudinal containing channel extending three or more feet. It is often noted, in the field, that these and similar inventions hold fast pine needles in great numbers which presents an unsightly appearance as well as create debris dams behind the upwardly extended and trapped pine needles. Such filter meshes and non-woven lofty fiber mesh materials, even when composed of finer micro-porous materials, additionally tend to clog and fill with oak tassels and other smaller organic debris because they are not resting, by design, on a skeletal structure that encourages greater water flow through its overlying filter membrane than exists when such filter meshes or membranes contact planar continuously-connected surfaces. Known filter mediums of larger openings tend to trap and hold debris. Known filter mediums smaller openings clog or “heal over” with pollen and dirt that becomes embedded and remains in the finer micro-porous filter mediums. At present, there has not been found, as a matter of common knowledge or anticipation, an effective water-permeable, non-clogging “medium-of-choice” that can be chosen, in lieu of claimed or illustrated filter mediums in prior art, that is able to overcome the inherent tendencies of any known filter mediums to clog when applied to or inserted within the types of water receiving wells and channels noted in prior art. Vail also discloses that filter mesh material 26 is recessed beneath a planar surface that utilizes perforations in the plane to direct water to the filter medium beneath. Such perforated planar surfaces as utilized by Vail, by Sweers U.S. Pat. No. 5,555,680, by Morin U.S. Pat. No. 5,842,311 and by similar prior art are known to only be partially effective at channeling water downward through the open apertures rather than forward across the body of the invention and to the ground. This occurs because of the principal of water adhesion: rainwater tends to flow around perforations as much as downward through them, and miss the rain gutter entirely. Also, in observing perforated planes such as utilized by Vail and similar inventions (where rainwater experiences its first contact with a perforated plane) it is apparent that they present much surface area impervious to downward water flow disallowing such inventions from receiving much of the rainwater contacting them. A simple design choice or anticipation of multiplying the perforations can result in a weakened body subject to deformity when exposed to the weight of snow and/or debris or when, in the case of polymer bodies, exposed to summer temperatures and sunlight. U.S. Pat. No. 4,841,686 to Rees teaches an improvement for rain gutters comprising a filter attachment, which is constructed to fit over the open end of a gutter. The filter attachment comprised an elongated screen to the underside of which is clamped a fibrous material such as fiberglass. Rees teaches in the Background of The Invention that many devices, such as slotted or perforated metal sheets, or screens of wire or other material, or plastic foam, have been used in prior art to cover the open tops of gutters to filter out foreign material. He states that success with such devices has been limited because small debris and pine needles still may enter through them into a rain gutter and clog its downspout opening and or lodge in and clog the devices themselves. Rees teaches that his use of a finer opening tangled fiberglass filter sandwiched between two lateral screens will eliminate such clogging of the device by smaller debris. However, in practice it is known that such devices as is disclosed by Rees are only partially effective at shedding debris while channeling rainwater into an underlying gutter. Shingle oil leaching off of certain roof coverings, pollen, dust, dirt, and other fine debris are known to “heal over” such devices clogging and/or effectively “water-proofing” them and necessitate the manual cleaning they seek to eliminate. (If not because of the larger debris, because of the fine debris and pollutants). Additionally, again as with other prior art that seeks to employ filter medium screening of debris; the filter medium utilized by Rees rests on an inter-connected planar surface which provides non-broken continuous paths over and under which water will flow, by means of water adhesion, to the front of a gutter and spill to the ground rather than drop downward into an underlying rain gutter. Whether filter medium is “sandwiched” between perforated planes or screens as in Rees' invention, or such filter medium exists below perforated planes or screens and is contained in a well or channel, water will tend to flow forward along continuous paths through cur as well as downward into an underlying rain gutter achieving less than desirable water-channeling into a rain gutter. U.S. Pat. No. 5,956,904 to Gentry teaches a first fine screen having mesh openings affixed to an underlying screen of larger openings. Both screens are elastically deformable to permit a user to compress the invention for insertion into a rain gutter. Gentry, as Rees, recognizes the inability of prior art to prevent entrance of finer debris into a rain gutter, and Gentry, as Rees, relies on a much finer screen mesh than is employed by prior art to achieve prevention of finer debris entrance into a rain gutter. In both the Gentry and Rees prior art, and their improvements over less effective filter mediums of previous prior art, it becomes apparent that anticipation of improved filter medium or configurations is not viewed as a matter of simple anticipation of prior art which has, or could, employ filter medium. It becomes apparent that improved filtering methods may be viewed as patenable unique inventions in and of themselves and not necessarily an anticipation or matter of design choice of a better filter medium or method being applied to or substituted within prior art that does or could employ filter medium. However, though Rees and Gentry did achieve finer filtration over filter medium utilized in prior art, their inventions also exhibit a tendency to channel water past an underlying gutter and/or to heal over with finer dirt, pollen, and other pollutants and clog thereby requiring manual cleaning. Additionally, when filter medium is applied to or rested upon planar perforated or screen meshed surfaces, there is a notable tendency for the underlying perforated plane or screen to channel water past the gutter where it will then spill to the ground. It has also been noted that prior art listed herein exhibits a tendency to allow filter cloth mediums to sag into the opening of their underlying supporting structures. To compensate for forward channeling of water, prior art embodies open aperatures spaced too distantly, or allows the aperatures themselvs to encompass too large an area, thereby allowing the sagging of overlying filter membranes and cloths. Such sagging creates pockets wherein debris tends to settle and enmesh. U.S. Pat. No. 3,855,132 to Dugan teaches a porous solid material which is installed in the gutter to form an upper barrier surface (against debris entrance into a rain gutter). Though Dugan anticipates that any debris gathered on the upper barrier surface will dry and blow away, that is not always the case with this or similar devices. In practice, such devices are known to “heal over” with pollen, oil, and other pollutants and effectively waterproof or clog the device rendering it ineffective in that they prevent both debris and water from entering a rain gutter. Pollen may actually cement debris to the top surface of such devices and fail to allow wash-off even after repeated rains. U.S. Pat. No. 4,949,514 to Weller sought to present more water receiving top surface of a similar solid porous device by undulating the top surface but, in fact, effectively created debris “traps” with the peak and valley undulation. As with other prior art, such devices may work effectively for a period of time but tend to eventually channel water past a rain gutter, due to eventual clogging of the device itself. There are several commercial filtering products designed to prevent foreign matter buildup in gutters. For example the FLOW-FREE .TM gutter protection system sold by DCI of Clifton Heights, Pa. Comprises a 0.75-inch thick nylon mesh material designed to fit within 5-inch K type gutters to seal the gutters and downspout systems from debris and snow buildup. The FLOW-FREE. TM device fits over the hanging brackets of the gutters and one side extends to the bottom of the gutter to prevent the collapse into the gutter. However, as in other filtering attempts, shingle material and pine needles can become trapped in the coarse nylon mesh and must be periodically cleaned. U.S. Pat. No. 6,134,843 to Tregear teaches a gutter device that has an elongated matting having a plurality of open cones arranged in transverse and longitudinal rows, the base of the cones defining a lower first plane and the apexes of the cones defining an upper second plane. Although the Tregear device overcomes the eventual trapping of larger debris within a filtering mesh composed of fabric sufficiently smooth to prevent the trapping of debris he notes in prior art, the Tregear device tends to eventually allow pollen, oil which may leach from asphalt shingles, oak tassels, and finer seeds and debris to coat and heal over a top-most matting screen it employs to disallow larger debris from becoming entangled in the larger aperatured filtering medium it covers. Tregear indicates that filtered configurations such as a commercially available attic ventilation system known as Roll Vent.RTM. manufactured by Benjamin Obdyke, Inc. Warminster, Pa. Is suitable, with modifications that accomadate its fitting into a raingutter. However, such a device has been noted, even in its original intended application, to require cleaning (as do most attic screens and filters) to remove dust, dirt, and pollen that combine with moisture to form adhesive coatings that can scum or heal over such attic filters. Filtering mediums (exhibiting tightly woven, knitted, or tangled mesh threads to achieve density or “smoothness”) employed by Tregear and other prior art have been unable to achieve imperviousness to waterproofing and clogging effects caused by a healing or pasting over of such surfaces by pollen, fine dirt, scum, oils, and air and water pollutants. Additionally, referring again to Tregear's device, a lower first plane tends to channel water toward the front lip of a rain gutter, rather than allowing it's free passage downward, and allow the feeding and spilling of water up and over the front lip of a rain gutter by means of water-adhesion channels created in the lower first plane. Prior art has employed filter cloths over underlying mesh, screens, cones, longitudinal rods, however such prior art has eventually been realized as unable to prevent an eventual clogging of their finer filtering membranes by pollen, dirt, oak tassels, and finer debris. Such prior art has been noted to succumb to eventual clogging by the healing over of debris which adheres itself to surfaces when intermingled with organic oils, oily pollen, and shingle oil that act as an adhesive. The hoped for cleaning of leaves, pine needles, seed pods and other debris by water flow or wind, envisioned by Tregear and other prior art, is often not realized due to their adherence to surfaces by pollen, oils, pollutants, and silica dusts and water mists. The cleaning of adhesive oils, fine dirt, and particularly of the scum and paste formed by pollen and silica dust (common in many soil types) by flowing water or wind is almost never realized in prior art. Prior art that has relied on reverse curved surfaces channeling water inside a rain gutter due to surface tension, of varied configurations and pluralities, arranged longitudinally, have been noted to lose their surface tension feature as pollen, oil, scum, Eventually adhere to them. Additionally, multi-channeled embodiments of longitudinal reverse curve prior art have been noted to allow their water receiving channels to become packed with pine needles, oak tassels, other debris, and eventually clog disallowing the free passage of water into a rain gutter. Examples of such prior art are seen in the commercial product GUTTER HELMET.RTM. manufactured by American metal products and sold by Mr. Fix It of Richmond, Va. In this and similar Commercial products, dirt and mildew build up on the bull-nose of the curve preventing water from entering the gutter. Also ENGLERT'S LEAFGUARD. RTM. Manufactured and distributed by Englert Inc. of Perthamboy N.J. and K-GUARD. RTM. Manufactured and distributed by KNUDSON INC. of Colorado are similarly noted to lose their water-channeling properties due to dirt buildup. These commercial products state such, in literature to homeowners that advises them on the proper method of cleaning and maintaining their products. None of theses above-described systems keep all debris out of a gutter system allowing water alone to enter, for an extended length of time. Some allow lodging and embedding of pine needles and other debris is able to occur within their open water receiving areas causing them to channel water past a rain gutter. Others allow such debris to enter and clog a rain gutter's downspout opening. Still others, particularly those employing filter membranes, succumb to a paste and or scum-like healing over and clogging of their filtration membranes over time rendering them unable to channel water into a rain gutter. Pollen and silica dirt, particularly, are noted to cement even larger debris to the filter, screen, mesh, perforated opening, and/or reverse curved surfaces of prior art, adhering debris to prior art in a manner that was not envisioned. Accordingly, it is an object of the present invention to provide a gutter shield that permits drainage of water runoff into the gutter trench without debris becoming entrenched or embedded within the surface of the device itself and that employs a filtration membrane configuration that possesses sufficient self-cleaning properties that prevent the buildup of scum, oil, dirt, pollen, and pollutants that necessitate eventual manual cleaning as is almost always the case with prior art. Another object of the present invention is to provide a gutter shield that employs a filtration membrane that is readily accessible and easily replaceable if such membrane is damaged by nature or accident. Another object of the present invention is to provide a gutter shield that better enhances the cosmetic appearance and blending of and with a building's rain gutter system than is offered by prior art. Another object of the present invention is to provide a gutter shield that will accept more water run-off into a five inch K-style rain gutter than such a gutter's downspout opening is able to drain before allowing the rain gutter to overflow (in instances where a single three-inch by five-inch downspout is installed to service 600 square feet of roofing surface). Other objects will appear hereinafter. SUMMARY It has now been discovered that the above and other objects of the present inventioin may be accomplished in the following manner. Specifically, the present invention provides a gutter shield for use with gutters having an elongated opening. Normally the gutters are attached to or suspended from a building. The gutter shield device comprises an extruded polymer uni-body of an angled first plane that rests on the front lip of a rain gutter and that adjoins a second downwardly angled perforated plane by means of a u-shaped channel that exists on the underside of the rear edge of said first plane. A second plane then joins to an upward vertical support leg that joins to a third perforated plane that angles downward (referenced to the rear wall of an underlying rain gutter) and inward toward the vertical leg. Second and third perforated planes thereby exibit an extended v-shaped configuration that directs water to the inward center of a rain gutter where it is then dammed by a vertical support leg that forces the water to pool upward and drop through perforations rather than channel past them. A fourth upwardly angled plane positioned above an behind the v-shaped configuration of planes two and three, joins to plane three by means of a u-shaped channel and vertical leg, joined to and beneath the forward edge of the u-shaped channel, that exists underside the forward (referenced to the front lip of a rain gutter) edge of plane four. The fourth plane has embedded in the center of its upper surface, a recessed channel to facilitate scoring and braking of the fourth plane. The fourth plane then joins to a rear vertical leg by means of a rear u-shaped channel. A filtration configuration is inserted in the extruded body of the gutter sheild device. The upper membrane of the filter configuration is comprised of smaller threads intersecting or adjoing larger ones at centermost points on the sides of the larger threads. The upper membrane thereby avoids presenting overlapping or underlapping thread joints that tend to trap and hold debris, while presenting a very water permeable surface that more readily lends itself to self-cleaning by way of flowing water. The upper membrane is sewn to the edges of an underlying skeletal structure that exhibits a strong siphoning action. The lower supporting skeletal structure beneath the upper membrane is comprised of ellipses spaced approximately 0.19 inch from end to end that have underlying vertical legs that join, at their lowest point, to a horizontal perforated surface that has underlying vertical extending legs. This combination of multiple elliptical surfaces so spaced, and of vertical planes above and beneath a perforated horizontal plane, exhibits strong tendencies to break forward water channeling, that often causes water to spill past a rain gutter, and redirect water downward and inward into an underlying rain gutter. The gutter sheild body may be inserted into and secured in a rain gutter by common methods now recognized as public domain. The filtration configuration is pinched on each lateral edge and then the edges are realeased into u-shaped edge receiving channels. The filtration configuration is supported in its center by an upward extending vertical leg that adjoins perforated planes two and three at their lowest edges. OBJECTS AND ADVANTAGES An object of the present invention is to provide a gutter shield device that employs a fine filtration combination that is not subject to gumming or healing over by pollen, silica dust, oils, and other very fine debris. Another object of the present invention is to provide a gutter shield body that can quickly and easily, in the field at the time of installation, be retrofitted with the current gutter coil employed in extruding the raingutters the present invention would be installed in. Another object of the present invention is to provide a filtration membrane that is not affixed to an underlying surface by adhesive means that tend to gum and trap debris in hot weather. Another object of the present invention is to provide a filtration configuration that does not allow its filter cloth or membrane to sag and develop debris catching pockets. Another object of the present invention is to provide a gutter shield device that disallows the entrance of debris into a raingutter in the event its removable filter requires replacement due to storm damage. Another object of the present invention is to provide a filtration configuration and encompassing body that eliminates any forward channeling of rain water. Another object of the present invention is to provide a filtration configuration that may more readily be inseted into or removed, if required, than has been realized in prior art. THE DRAWING FIG. 1 . is a partial or fragmentary sectional edge view of the present invention displaying the profile of the main body of the gutter cover as it would appear extruding from a die. FIG. 2 . is a partial or fragmentary top perspective view of the main body of the present invention. FIG. 3 . is a partial or fragmentary sectional edge view of a component of the present invention displaying the profile of a supporting skeletal filtration structure that is an insertable component employed by the present invention. FIG. 4 . is a partial or fragmentary top perspective view of the supporting skeletal filtration component employed by the present invention. FIG. 5 . is an enlarged isolated view of a filter medium which affixes to the supporting filtration skeleton component employed by the present invention. FIG. 6 . is a partial or fragmentary top perspective view of the completed filtering component of the present invention as it appears prior to insertion into a receiving channel of the main body of the present invention. FIG. 7 . is a partial or fragmentary sectional edge view of the present invention displaying the profiles of it's main body with filtration skeleton inserted. FIG. 8 . is a partial or fragmentary top perspective view of the preferred embodiment of the present invention displaying the main body of the gutter cover with inserted filtration skeleton and affixed (to the skeleton) filter medium. FIG. 9 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, and shows an end view of a sectioned K-style gutter and a side or end view of an overlying and attached gutter cover section. FIG. 9 a . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional rear insertable filter medium. FIG. 10 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional securing ledge. FIG. 11 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional rear extension component. FIG. 11 a . is a partial or fragmentary top perspective view of an optional rear extension component of the present invention. FIG. 12 . is a partial or fragmentary top perspective view of the main body of the present invention and of an optional covering sleeve component. FIG. 12 a . is a partial or fragmentary top perspective view of the main body of the present invention and of an optional covering sleeve component slid onto the top shelf of the main body of the present invention. FIG. 13 . displays top perspective views of the main body of the present invention illustrating an optional width-adjustable element or feature of the gutter cover. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now specifically to the drawings, a gutter cover (protector) body 1 with an insertable “multi-level filter” 32 according to the present invention is illustrated in FIG. 8 . The gutter protector material is to be a polymer that is reduced to liquid form through screw compression of plastic “tags” or reduced to liquid form through other means. This liquid plastic mixture will then be extruded through a single block die embodying a profile of the body of the invention. The extruded material is rigid or semi-flexible PVC or Polypropylene or other heat, chemical, and UV resistant polymer. The preferred thickness of the extruded polymer material forming the gutter protector cover will range from 0.05 to 0.07 inches. The extruded material is suitably thick to maintain its shape and not deform or dip under load bearing weight of snow and ice or deform when exposed to high ambient temperatures which have caused prior art of lesser polymer thickness to deform vertically upwards and downwards allowing open-air gaps to form from one piece of prior art to the next when they rest abutted side by side. These gaps may allow debris entrance into a rain gutter. The PVC, Polypropylene, or other polymer will contain sufficient titanium oxide, carbon black, or other UV inhibitors to resist breakdown of structural integrity for a period of at least 10 years when exposed to normal cycles of “Florida Sun” (sunlight equivalent to that experienced over a 10 year period of outdoor exposure to weathering conditions in the state of Florida). The gutter protector body may be extruded in any length but it is preferred that the extruded body be cut into 4 to five foot lengths, at the point of manufacture, while exiting a plastics extrusion cooling tray. Such lengths may be installed by one individual while allowing for as few joints or seams as possible to exist when the present invention is installed over the length of a gutter. The extruded body is 5.4 inches wide. Referring to FIG. 10 it is illustrated that the extruded body will rest inside the topmost opening of a conventional K-style 5 or 6 inch rain gutter 33 supported by spikes or “hidden hangars” 28 upon which the rear horizontal leg of the body 20 rests and supported by the front lip of the K-style rain gutter upon which the front “lip” 9 of the extruded body rests, such front lip 9 having an approximate length of 0.757 in. FIG. 10 further illustrates the body may also be supported in the rear by affixing a flexible semi-concaved metal or plastic extrusion 27 (0.07 inches thickness or less) into the fascia board of a building structure and allowing it to extend outward away from the fascia board sufficient length to enable semi-concaved extrusion 27 to insert into the rear Channel 22 of the body to support the body at the rear. This may be desirable to ensure high winds may not uplift the extruded gutter cover out of the rain gutter as does occur with prior art. This may also ensure a level plane is created from one five length of the extruded body to the next at the rear in instances where reliance on gutter spikes for support of the rear portion of the extruded body may be inadvisable in instances where the gutter spikes may be driven at uneven heights through the rear of a rain gutter into a fascia board disallowing the extruded gutter cover 1 from maintaining a level horizontal plane between adjoining (abutted) pieces. A level plane from one gutter cover 1 to the next when installed inside a rain gutter is important to disallow vertical gaps from occurring between pieces as they may in prior art which may provide an entrance for debris into a rain gutter. The profile of the body of the gutter protector illustrated in FIG. 1 shows the extruded body includes a rear horizontal leg 20 approximately 0.4 inches in length which may serve to rest on a gutter spike or hidden gutter hangar for a length of at least 0.4 inches at point of contact which serves to distribute any weight upon the gutter cover body over a greater surface area of a supporting spike or hanger than a simple extension of rear leg 19 , whose approximate length is 0.6 in., would provide in the absence of rear horizontal leg 20 . FIG. 2 reference numeral 20 illustrates that a rear horizontal leg of the extruded body 1 is integral to the body and extends the entire length of the body and is perforated to allow rear drainage surface area in the event wind blown rain or melting ice flows rearward rather than forward into filtration membrane 32 . FIG. 9 illustrates that rear horizontal leg 20 also may serve as a locking mechanism due to its positioning beneath hex-head or other screw fasteners 30 used to secure a hidden hangar and rear of a rain gutter to a fascia board in such instances when hidden hangars are the chosen method of fastening. It can be seen in FIG. 9 a that rear horizontal leg 20 may also serve as a platform on which a mesh or other type filter 31 approximately ¾ inch to 1½ inch wide and one inch tall may rest to provide a rear barrier to debris that may possible be wind blown to the rear of the gutter protector body. Referring, again, to FIG. 1 it can be seen that the extruded gutter cover body includes a rear support leg 19 that serves to provide rear vertical support for the gutter cover body and which includes “score lines” 21 which an installer may score with a utility knife or other scoring device if necessary. Such scoring will prevent running cracks up the rear support leg 19 from occurring if the rear support leg should ever need to be notched out to fit over a gutter spike that may be positioned too high through or above the rear of a rain gutter. In practice, in the field, improper positioning of the gutter spike occurs infrequently and may cause the gutter cover body to rest unevenly at varying heights inside the rain gutter necessitating that the rear support leg 19 and rear horizontal leg 20 be notched out to allow the rear of the gutter cover body to rest in a lower position inside the rain gutter to maintain an attractive low profile and smooth even-plane transition from section to section of the body of the present invention. Referring again to FIG. 1, rear support leg 19 of the extruded body extends vertically upwards at an approximate 85-degree angle and an approximate 0.6-inch length. Support leg 19 then bends forward at approximately a 75 degree to 95-degree angle to form a shelf 23 approximately 0.2 inches in length. Shelf 23 extends upward approximately 90 degrees forming vertical leg 18 with an approximate length of 0.21 inches. Vertical leg 18 then angles forward approximately 90 degrees into a higher shelf 17 whose approximate length is 0.3 inches. Referring now to FIG. 10 it is seen that bottom shelf 23 , vertical leg 18 , and higher shelf 17 of the extruded body form a recessed “receiving” channel 22 approximately 0.2 inches in depth and 0.07 inches wide which may serve to receive plastic or metal inserts or fasteners 27 that may be used to create a rear to forward tension mount of the extruded body. Referring now to FIGS. 12 and 12 a , it is illustrated that channel 22 may additionally may serve to act as a the first of two receiving channels of the extruded body, the second receiving channel being channel 23 that may receive and hold fast and permanently an aluminum, zinc, or copper metal cover 35 that may be clipped onto the extruded body. This clipped on cover 35 may serve to join two extruded body pieces together by spanning and covering the joint formed at their side-by-side abutment when such pieces are installed in a rain gutter. This clipped on cover 35 may further serve to provide fungicidal properties when made of zinc that would discourage moss mold or mildew growth on the invention, which is an improvement, not found in prior art. The clipped on cover 35 may further serve to allow color and material matching of the plastic extruded body to aluminum, copper, and other metal rain gutters which is an advantage and property not found or suggested in prior art. The co-use of two such materials, polymer and metal, in a leaf guard on copper or other expensive metal rain gutters would provide a great economical alternative to the use of solid copper leaf guards which naturally employ thicker and thereby more expensive copper in their design. The dimensions of such an extruded 0.019 or thinner metal cover would be such that it's underside 36 would be approximately 5 percent to 15 percent greater than the exterior portion of the extruded plastic body of the invention it covers. Such extruded metal cover may also serve to act as an extension for the plastic extruded body it covers to allow for a fit rain gutters larger than standard 5″ K style gutters by widening the clip on metal shelf 35 to accommodate 6 inch or wider rain gutters. Referring again to FIG. 1, shelf 17 extends horizontally 0.3 in. and then upward into a curve 2 a such curve having an exterior radius of approximately 0.137 and an interior radius of approximately 0.073 inch. The reverse of curve 2 a of the extruded body extends forward in a somewhat horizontal plane 2 angled downward approximately 5 degrees for a distance of approximately 1.5 to 1.75 inches. Horizontal plane 2 embodies a small recessed channel 59 across its entire length of sufficient depth to allow for scoring and breaking of the horizontal plane. FIG. 13 illustrates such scoring and breaking of recessed channel 59 may be optionally employed by the installer in instances where a horizontally compressed rain gutter does not allow for easy installation of the invention: the severed rear portion of the extruded body 36 may then be placed over the front severed portion of the extruded body 37 as illustrated in FIG. 13 and affixed by polymer cement or fasteners such as plastic bolt 38 and plastic nut 39 creating such overlap distance of the rear severed portion of the extruded body over the front severed extrusion of the severed body as the installer deems necessary to create an ideal adjusted extruded body width for placement in a horizontally compressed portion of a rain gutter. Referring again to FIG. 1, Horizontal plane 2 , after extending a distance of approximately 1.5 inches, will then “fork” into two extensions: one extension; 3 , continues to extend outward angled downward from the 1.5 inch point an additional 5 to 10 degrees to form a top shelf approximately 0.28 inch in length. The other extension 4 of Horizontal plane 2 extends downward at an approximate 85 degree angle for a distance of 0.125 inches and then angles forward 90 degrees into a plane 16 approximately 0.28 inches in length. Extension 3 extension 4 and plane 16 form a recessed “receiving” channel 24 with a depth of approximately 0.28 inch and a width 55 of approximately 0.125 inch which serves to secure the edge of the multi level filter portion of the invention and to receive, if opted for, the curved edge of a metal cover which may be clipped onto Curve 2 a , Horizontal plane 2 , and extension 3 as illustrated in FIG. 12 a. Referring again to FIG. 1; Plane 16 of the extruded body continues and then angles sharply downward at an approximate 80 to 85 degree angle for a distance of approximately 0.4 inches to form plane 5 . Plane 5 extends downward and then angles forward at an approximate 22-degree angle-forming plane 15 . Plane 15 has an approximate length of 0.94 inch and is perforated as illustrated in FIG. 2 with perforations 0 approximately 0.065 inch wide, 0.125 long. Perforations 0 are aligned end-to-end and spaced approximately ¼ inch apart in rows, which extend the length of the extruded body, such rows being spaced approximately 0.145 inch apart. Referring again to FIG. 1, Plane 15 forks into an extension and a continuance: the extension of plane 15 is plane 6 which extends upwards as an extension of plane 15 at an approximate 90 degree angle. Plane 6 will act as a support for the insertable filter portion of the invention and presents an improvement not found in prior art in that it will act as a dam that forces water to back up and drip through the rear most rows of perforations of plane 15 rather than continue forward with enough speed and depth of water flow to spill over the front lip of the rain gutter. Such occurrence of water spill is common in prior art, which relies solely on water adhesion principals. Planes 5 , 15 , and 6 of the extruded body form a water receiving well with a perforated bottom shelf 15 that will direct water into a rain gutter when acting in conjunction with the water dam formed by plane 6 as described in the preceding sentence. Referring again to FIG. 1, Plane 15 , in addition to forking upwards into plane 6 also continues on at an approximate 22 degree upward angle beginning at the base of Plane 6 and extends into a perforated plane 13 approximately 0.95 inch long. This angling upward of plane 13 toward the front lip of the gutter presents an improvement not found in prior art in that water which contacts plane 13 will not continue on a forward flow toward the top front lip of a rain gutter due to water adhesion principals where it may then spill outside the rain gutter. Instead, the water that contacts plane 13 will follow the downward angling plane 13 and be more surely and intentionally directed into a rain gutter. The perforations of plane 13 are identical to those of plane 15 : 0.065 inch wide, 0.125 long, each perforation spaced end to end approximately 0.25 inches aligned in rows the length of the extruded body such rows being spaced approximately 0.145 inch apart. Plane 13 extends forward approximate 0.95 in and then angles downward approximately 16 degrees into plane 12 . Plane 12 extends forward approximately 0.33 inch at which point it forks into an extension and a continuance: the extension, plane 7 forks upward at an approximate 80 degree angle for a distance of approximately 0.14 inch at which point plane 7 terminates in a “T” configuration. The “T” configuration has a rearward (toward the rear of the extruded body) horizontally extending section, plane 8 , having a length of approximately 0.25 inch. Receiving channel 24 a is formed by planes 12 , 7 , and 8 and such channel has an approximate width 56 of 0.125 inch. This channel acts to receive and secure the forward edge 54 of supporting skeletal filter component 57 as illustrated in FIG. 8 . The forward extension of the “T” is an extending plane, 9 , that angles approximately 7 degrees downward for a distance of approximately 0.757 inch where it then angles downward 45 degrees into plane 10 , which measures approximately 0.45 inch in length. The continuance of plane 12 is for a distance of approximately 0.24 inches after its vertical fork; plane 7 giving plane 12 a total length of 0.57 inch. Referring again to FIG. 1 it may be seen that planes 6 , 13 , 12 , 7 , and 8 form a receiving well of the extruded body which will direct rain water through its perforations into a rain gutter. FIG. 1, planes 12 , 7 , and 8 further illustrate a recessed receiving channel 24 that may receive and secure both an inserted edge of the multi filter employed by the invention as is illustrated in FIG. 7 and FIG. 8 . FIG. 12 a illustrates that a “clip on” metal cover 40 may be inserted over planes 8 , 9 , and 10 to achieve an optional aesthetic matching of colored aluminum or copper between the present invention and the underlying gutter it protects and/or to achieve the improvements previously described in the last sentence of page 4 and the fist sentence of page 5 of this disclosure. FIG. 11 illustrates Channel 22 may serve as a receiving channel for polymer, metal, or other semi-flexible formed or extruded inserts with profiles similar to extension 41 which may be placed or affixed with adhesives into Channel 22 and may then serve as an extension of the extruded body 1 which extends rearward and compresses against the rear wall of a rain gutter, hidden hangar, or fascia board to create a rear to forward tension mount of the extruded body into the rain gutter at the discretion of the installer. The amount of mounting tension created may be varied by the length of the top shelf 42 of the extruded or formed extension 41 . Referring now to FIG. 3 there is illustrated the profile of a perforated filter skeleton 43 . The width of filter skeleton 43 is approximately 2.5 inches and is an extruded polymer of approximately 0.04 to 0.06 inches. Plane 44 is approximately 0.58 inch and contains perforations 0 , such perforations being of elliptical shape approximately 0.45 inches long and 0.22 inch wide. The perforations 0 are positioned as close to vertical leg 45 as possible and have a wider top opening than bottom creating a taper which more readily captures and directs rain water than a simple straight through punch. Horizontal plane 44 t-junctions into vertical leg 45 whose approximate length is 0.35 inch. Leg 45 has a curved bottom 46 , such curved surface facilitating the dropping of water off of leg 45 downward into the rain gutter. Leg 45 is capped by ellipse 47 . Ellipse 47 has dimensions of approximately 0.13 inch width and 0.08 inch height. The elliptical curved surfaces 47 resting on vertical legs 45 , create water-channeling paths that exhibit siphoning effects stronger than has been realized in prior art. These “t” configurations, as well as their approximate spacing of 0.19 inch from subsequent ellipses and legs, create act as an ideal support for warp-knitted filter membrane 50 (shown in FIG. 5 in an exploded view): Such “t” configurations, and their spacing, enhance the self-cleaning properties inherent in filter membrane 50 . Additionally, they present a breaking of any water channeling paths to the front of a rain gutter lip noted in prior art. FIG. 6 illustrates that filter membrane 50 will be affixed to filter skeleton 43 . The downward curves and spacing of the ellipses 47 offer an improvement over prior art in creating multiple curved surface water channels that direct toward a vertical leg resting on a horizontal perforated plane that employs downward extending legs to continue the flow of water downward rather than forward. This configuration creates stronger siphoning action than is created in prior art relying on elliptical ocean-wave shapes to channel water or downward extrusions positioned beneath perforations or screens. The channeling of water almost fully around an ellipse that is broken by a vertical downward extending leg better captures water and directs it downward preventing back-flow of received water against incoming water noted in prior art. Vertical legs 45 downward extensions beneath planes 44 and 48 ensure the water adhesion of flowing rain water is broken at the most opportune moment to ensure the directed flow of water into a rain gutter. Perforated planes 48 are approximately 0.25 inches in width. Viewing from right to left, the extruded filter skeleton continues from the first vertical leg 45 whose length is approximately 0.35 inch into an upward extension where it terminates into an ellipse 47 . Vertical leg 45 is intersected approximately 0.2 inch down by forward extending perforated horizontal plane 48 . Planes 48 are approximately 0.25 inches in length. Perforated plane 48 continues forward until it intersects the second vertical leg 45 approximately 0.2 inch below ellipse 47 . Vertical leg 45 extends approximately 0.22 inch downward from perforated plane 48 in order to break any surface tension of water adhering to perforated plane 48 and redirect it downward into a rain gutter. A second perforated plane 48 extends forward horizontally from a second vertical leg 45 until it intersects a third vertical leg 45 . Third vertical leg 45 is capped by an ellipse 47 as are all vertical legs of filter skeleton 43 . A third perforated plane 48 extends forward horizontally from third vertical leg 45 until it intersects a vertical leg 51 whose length from ellipse 47 to it's lower most surface 46 is approximately 0.45 inch. A fourth perforated plane 48 extends forward horizontally from vertical leg 51 for a distance of approximately 0.25 inch where it then right angles upward into a vertical leg 54 whose approximate length is 0.2 inch. Vertical leg 54 extends upward into an ellipse 47 . Directly beneath the ellipse which caps vertical leg 54 , a horizontal perforated plane 55 extends forward for a distance of approximately 0.45 inch. Planes 44 and 52 each have the endmost section of their length non-perforated to allow space for a sewing seam. filter membrane 50 will be sewn onto filter skeleton 43 at these endmost sections of planes 44 and 52 . Referring to FIG. 3 and viewing supporting skeletal component 57 left to right: each combination left to right of ellipse 47 , vertical leg 54 , perforated plane 48 , vertical leg 51 , ellipse 47 and of ellipse 47 , vertical leg 51 , perforated plane 48 , vertical leg 45 , ellipse 47 and of ellipse 47 , vertical leg 45 , perforated plane 48 , vertical leg 45 , ellipse 47 creates water receiving wells whose components (by means of their structural configuration and spacing) act to slow the flow of rainwater as well as capture and direct rain water downward into a rain gutter in an improved manner over prior art. It can be seen in FIGS. 3 and 4, that planes 44 and 52 are positioned on higher planes than planes 48 . This is done to allow the top of the elliptical planes 47 to remain on a level or slightly recessed plane with planes 3 and 8 of the extruded body as illustrated in FIG. 11 . This will disallow a damming effect that could lead to debris build up behind the insertable filter and encourage debris to fall or be wind blown off of the invention. It can also be seen in FIG. 11 that, viewing from right to left, the third vertical leg 45 abuts the upward extending leg 6 of the extruded body. This feature discourages the product from shifting. Referring again to FIG. 3 it can be seen that, viewing from right to left, the forth leg 51 is of greater length than the preceding downward extending legs 45 . The length of leg 51 is approximately 0.48 inch. This illustrates that the length of legs may vary to prevent forward flow of water to the front of the gutter by decreasing water tension paths along the bottom of the filter membrane. The ellipses, too, may exist at different planes which would further facilitate the capturing of rainwater and the direction of it downward into the rain gutter. Referring again to FIG. 3 it is seen that vertical leg 54 does not extend beneath perforated plane 48 . The reason for this is illustrated in FIG. 7 where it is seen that extending vertical leg 54 beneath the plane 48 would cause the filter skeleton to rise above a level or slightly recessed plane than exists between 3 and 8 of the extruded body. An extension of vertical leg 54 beneath perforated plane 48 would cause it to contact plane 13 and push the filter skeleton upwards. The vertical height of vertical leg 54 is approximately 0.17 inches from its bottom most surface up to the point it contacts ellipse 47 . FIG. 5 is an exploded view of filter membrane 50 , the type of filtration fabric illustrated affixed to filter skeleton 43 as illustrated in FIG. 6 . It can be seen in FIG. 5 that small cylindrical threads of polymer extrusion 55 are made to pass through larger threads 56 . This unique method of fabric formation offers an improvement over prior art in that this configuration of smaller curved surfaces passing through, rather than woven or knitted above and beneath larger threads, increases the fabric's ability to capture and direct water. This method of fabric formation offers another improvement over prior art in that it encourages dirt and debris to be less likely to be retained by the fabric and therefore less likely to clog the filtration cloth than other filters employed in prior art: woven, weaved, knitted, non-woven lofty, are able to accomplish. The largest distance between any two larger threads is to be less than {fraction (8/100)} of an inch, which prevents the smallest of debris from lodging within an open (space between threads. The preferred embodiment of this invention is illustrated in FIG. 9 and FIG. 12 a .: An extruded polymer body with extruded multi level filter that employs water receiving channels framed by curved ellipses resting on vertical supporting, lower extending legs covered by a filtration cloth as illustrated in FIG. 5 and FIG. 6 with a slide on or clip on metal covers as illustrated in FIG. 12 a. Operation of the Main Embodiment Referring to FIG. 9, there is illustrated the present invention: a gutter protection system that consists of a main body 1 and an insertable filter skeleton 43 covered with a filter membrane 50 . Filter Membrane 50 is composed of intersecting threads. (An exploded view of the interconnecting structure of the threads is illustrated in FIG. 5 ). Referring to FIG. 10 The present invention is illustrated as inserted into the top water receiving opening of a k-style rain gutter 33 and resting on a gutter hangar 28 . It is illustrated that the present invention rests wholly beneath the sub roof 60 and roofing membrane 61 of a building structure. Referring to FIG. 12, it is illustrated that the present invention will be affixed to an existing rain gutter in two stages. First, a main body 1 will be placed inside the open top of a rain gutter and then may be secured in place by several means: Rear horizontal leg 20 will rest upon a hidden hangar 28 and prevent body 1 from displacing by locking beneath the head of fastening screw 30 . The front of the present invention is snapped into place and secured to the front lip of the k-style gutter by planes 9 , 7 , & 11 of the body. Sub-heading 1 Covering of Joints, Aligning of Adjoining Sections, and Color Matching Once this is accomplished, main body 1 offers improvement over prior art in offering a method of aligning adjoining sections of the invention in a manner that allows joints between adjoining body members to be covered. This covering of joints and joining of abutted sections of the invention is accomplished by means of a roll-formed or “braked” sleeve (see FIG. 12 and 12 a , sleeve 35 ). The resulting absence of debris-allowing joints is not realized in prior art intended to retrofit existing rain gutters. Referring FIG. 1, there is illustrated a recessed channel 22 . Recessed channel 22 acts as the first of two receiving wells 22 & 24 for a roll-formed or job-site “braked” metallic cover 35 which may be clipped onto the top shelf 2 of the present invention (see FIGS. 12 & 12 a ). This feature offers improvement over prior art in that no prior art offers the ability to specifically color match to it's underlying rain gutter at the time of installation. The present invention allows the installer to quickly break matching gutter coil to clip into and cover top shelf 2 and top shelf 9 as is illustrated in FIG. 12 a . Metallic sleeves 35 & 40 may also serve to further align each sectioned body of the present invention and maintain consistent edges and heights between adjoining bodies. This is an optimal method of ensuring consistency of height and edge alignment between adjacent sections not known in prior art. Sub-heading 2 Vertical Height and Horizontal Width Adjustments Another improvement achieved by the present invention, not known in prior art, is its ability to provide a means of extending body width to accommodate standard sized commercial sized gutters with 4, 5, 6, and 7 inch widths. Widening may be accomplished by breaking or rollforming the metal cover 35 (FIG. 12 a ) to a width wide enough to effectively extend the present invention's body rearward. Sub-heading 2a Vertical Adjustments In the event body 1 is installed in a rain gutter affixed to a fascia board by gutter spikes, the present invention offers an improvement not found in prior art by offering a quick, at-the-point-of-installation, method of adjusting the height of the body to ensure it remains consistent. The body 1 of the present invention offers improvement over prior art by allowing for adjustment of it's rear vertical leg 19 by scoring and breaking of the rear leg at points 21 . It is known gutter spikes, often employed to secure a rain gutter to a fascia board, are driven in and remain at uneven heights at the rear of the rain gutter. Prior art, which requires a supporting of a rear leg or rearward part of invention body, has not foreseen or allowed for simple height adjustments to be made, which would accommodate prior art bodies to supporting, gutter spikes. Such adjustments may be necessary to maintain a consistent level height of gutter protection units for cosmetic as well as functional reasons. The improvement accomplished by the present invention is that such height adjustment may be accomplished quickly at the point of installation with a simple blade (to score point 21 ) and pair of scissor snips to clip the rear leg structure from rear horizontal leg 20 up through rear vertical leg 19 to the scored recess 21 . The scored mark ensures that the portion of rear vertical leg 19 so scored and cut will break off easily. Prior art does not allow for such simple controlled height adjustment at the point of installation (possibly while the installer is on an extension ladder). Sub-heading 2b Width Adjustments The body 1 of the present invention offers another improvement over prior art designed to be inserted into the top of a rain gutter, rather than rest upon the top surface of a subroof or roofing membrane, such as U.S. Pat. No. 6,134,843 to Tregear, U.S. Pat. No. 5,619,825 to Leroney, etc,. by allowing for adjustment of the main body by means of a pre-scored recessed channel 59 (FIGS. 2 & 13 ). Scoring of channel 59 allows the clean breaking and refastening of the body 1 to achieve a means of adjusting the present invention to accommodate both 4 inch and 5 inch gutters. FIG. 13 illustrates that the body 1 of the present invention may broken, then rejoined in a fashion that creates shorter body widths to accommodate the varying widths of a single run of gutter length. It is known that lengths of installed gutter seldom maintain a consistent width due to irregularities in fascia boards they are attached to. Prior art such as is illustrated in U.S. Pat. No. 5,495,694 to Kuhns, U.S. Pat. No. 5,459,965 to Meckstroth, etc., that require a resting of their body on top of or directly beneath shingles or other roofing materials do not have an intrinsic ability to accommodate varying gutter widths. This leads to such prior art presenting an uneven appearance along their rear edges which varies with the uneven width of a gutter they are attached to. This unevenness of edges at the rear of such products, as well as the dipping of subroof structures that often occur beneath the shingles such prior art may rest upon or be affixed to, allows open air spaces to exist at the rear of such products or from side-edge to side-edge of adjoining pieces. Debris may then enter through into a rain gutter or become trapped in the open air spaces. Because this problem is known, installers of prior art are known to screw the rear of such products into their underlying supporting roof structure, which can present the potential for roof leaks and the voiding of roofing manufacture warranties. Prior art has offered limited adjustment of width, usually by relying on body tension to extend width, as illustrated in such prior art as U.S. Pat. No. 5,619,825 to Leroney, but such extension of body width found in prior art is meant only accommodate one gutter width i.e.: 5 inch or 6 inch and does not allow for utilization of prior art over a span of varying standard gutter widths. Added width of span accomplished by tension weakens the strength of such invention's affixture to the raingutter since the pressure of tension is weakened. Prior art does not allow for the shrinking or widening of body width offered by the present invention in such fashion as to allow installations on narrower gutter widths than 5 inch or as to allow consistently secure installations on wider gutter widths than 5 inch. Prior art that does allow for installation on varying standard gutter widths such as is found in U.S. Pat. No. 5,660,001 to Albracht and U.S. Pat. No. 5,640,8090 etc, is undesirable because of the required securing of such prior to or beneath roofing membranes, which has been found to cause failures of roofing membrane integrity. Sub-heading 3 Water Receiving Wells Referring again to FIG. 2 it is illustrated that the body 1 incorporates two recessed perforated planes 13 & 15 , separated by a vertical leg 6 . Both planes angle downward and inward into the body of an underlying raingutter. This allows the present invention to offer improvement over prior art as follows: Referring to FIG. 1 : there is illustrated two recessed water-receiving perforated wells 15 and 13 , which direct water, flow downward to a vertical leg 6 . The downward angle of perforated well 13 , away from the front lip 9 and front lip of a rain gutter offers improvement over prior art U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, and other prior art in that it forces water to cease any forward flow to the front of a rain gutter where it may spill past the raingutter as has been noted in prior art. Prior art has not effectively dealt with this noted problem. Reverse curved and hooded gutter protection methods such as U.S. Pat. No. 5,491,998 to Hansen do redirect water flow rearward into the raingutter but have not recognized the noted tendency of debris to follow the water around the curved surfaces they employ into the rain gutter as well. Additionally, such prior art is known to lose most of it's water adhesive properties over time as pollen, oil leaching from asphalt shingles, and other pollutants, coat and remain on the curved surfaces such prior art employs. Downward sloping plane 15 , also, prevents forward flow and resulting spilling of water to the ground, by acting in conjunction with vertical leg 6 . Vertical leg 6 , serves the dual purpose of acting as a center and downward water channeling support for the filtration membrane 50 and Skeleton 43 (See FIG. 9 ), and as serving as a dam that slows forward rushing water in recessed well 5 , 15 , 6 to slow and drain through the perforated plane 15 . Sub-heading 4 Filter Membrane and Skeleton Once installation and, if necessary, adjustment of the body and/or covering of the body 1 of the present invention is achieved, a filter membrane and skeleton will then be inserted into the recessed channel of the present invention. (See FIG. 2, then FIG. 8 and FIG. 9 ). Several improvements over prior art are offered by the filter membrane and skeleton employed by the present invention: Sub-heading 4a Filter Skeleton Referring now to FIG. 3 there is illustrated a filter member: a multi-level supporting structure upon which a wire or cloth membrane composed of intersecting threads shall rest. Prior art employing filtration cloth or membrane, which rests over open apertures e.g.: U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, etc. exhibits a property of preventing rainwater from entering the open apertures beneath the filtration cloth. In practice, in the field, it is often observed that volumes of water will travel around the underlying perforations, beneath the filter cloth or membrane covering them, due to water adhesion principals. The water will then feed toward the front of prior art, rather down beneath it and into a rain gutter, and will flow past the top front lip of a rain gutter. This common occurrence in prior art occurs for several reasons. Perforated surfaces existing in a single plane, such as is employed in U.S. Pat. No 5,595,027 to Vail, or as exists in the Commercial Product SHEERFLOW. RTM. Manufactured by L. B. Plastics of N.C., and similar prior art tend to channel water inventions sought to correct this undesirable property by either tapering the rim of the open perforation and/or creating downward extensions of the perforation (creating a water channeling path down through open air space) as exhibited in prior art U.S. Pat. No. 6,151,837 to Ealer, or by creating dams on the plane the perforations exist on, as exhibited in prior art U.S. Pat. No. 4,727,689 to Bosler. Such prior art has been unable to ensure all water would channel into the underlying rain gutter because the water, that did, indeed, travel through the open apertures on the top side of these types of perforated planes or screens, would also travel along the underside of the screen wires or perforated planes, as it had on top of these surfaces, and still continue it's undesirable flow to the front of the invention and front lip of the underlying rain gutter, due to water adhesion. Additionally, this “underflow” of water on the underside of the perforated planes and screens illustrated in prior art exhibits a tendency to “back flow” or attempt to flow upwards through the perforations inhibiting downward flow of water. This phenomenon has been noted in practice, in the field when it has been observed that open air apertures appear filled with water while accomplishing no downward flow of water into the underlying rain gutter. Other inventors sought to eliminate this undesirable property by employing linear rods with complete open air space existing between each rod, This method of channeling more of the water into the rain gutter exhibits more success on the top surface of such inventions, but it fails to eliminate the “under channeling” of rainwater toward the front of the invention due to the propensity of water to follow the unbroken interconnected supporting rods or structure beneath the top layer of rods. Referring again to FIG. 3, the structure of the present invention improves the flow of water into the rain gutter over prior art, significantly, as has been observed in practice, in the field. This improvement is accomplished by allowing cylindrical rods 47 , with unbroken air space existing between them, to rest upon vertical leg supporting structures, which disallow any connecting path for forward water channeling due to water adhesion. Supporting structures 45 , 46 , 51 , & 54 are, indeed, each connected to the other by perforated planes 48 . However, this connection is broken by several factors, which disallow a forward flow of water. Water, instead, is forced downward into the rain gutter with no water adhesive path toward the front of the invention existing. This is accomplished by resting the rods 47 on slim vertical supports 45 , 46 , 51 ,& 54 . Doing so creates a “t” configuration unlike the simple rod structures of prior art. The present invention is an improvement in two instances: First, water that channels around simple rods, rather than “t” structures exhibits less siphoning action due to the water colliding on the underside of the rod after traveling down the opposing curved sides of the rod. This collision of water slows downward water flow by creating a back flow or upward flow of water against the rainwater attempting to channel downward along the curved surfaces of the rod. The “T” configuration of the present invention prevents such reverse flow or back flow of water against the incoming water flow by creating a continuing path of water flow away from water traveling down the opposite side of the “t”. This allows the filter skeleton 43 to create a stronger channeling or siphoning action on the incoming rainwater than prior art is able to exhibit. The “t” configuration also offers improvement over prior art because it creates an absolute break in the water adhesion flow on the bottoms of vertical legs 45 , 46 , 51 , & 54 . Water which will travel down rods 47 , then though the open air apertures 0 which exist in planes 48 , will next adhere to and travel down the lower (beneath planes 48 ) portions of the vertical legs of the “t”. Water traveling down the vertical legs, at this point, is an improvement over prior art such as U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, because it has discontinued it's forward flowing path on the underside of the perforated plane, as is common in the prior art, and is now being channeled, again, downward toward the inside of the rain gutter. Prior art, U.S. Pat. No. 4,745,710 also temporarily accomplishes this downward flow utilizing it's rod-supporting structure, but not nearly as effectively due to the interconnection of the underlying support structure, which provides a forward flowing water path by means of water adhesion along an unbroken surface. The improvement of the “t” configuration over prior art is again accomplished by a third, completely disconnected path of water flow, achieved at the lower termination of the vertical legs 45 , 46 , 51 , & 54 . Water, at these points, may only flow downward into the rain gutter. This is due to the length of the downward extensions of the vertical legs, which, by design, disallow backflow of water on the underside of the perforated planes 48 , or forward flow of water along a water adhesion path to the front lip of the rain-gutter. Filter Skeletal structure 43 of the present invention creates a siphoning action and ensures a downward, rather than forward flow of water not exhibited by prior art. Referring to FIG. 5 there is illustrated a cloth or wire filter membrane 50 , which employs intersecting threads. This membrane exhibits an improvement over other filtering and screening methods illustrated, representatively, in prior art U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, etching that it exhibits no tendency to trap and hold debris. The above mentioned prior art, even when employing micro-aperatured cloth, (due to adhesive actions of pollen, oil, pollutants, and silica dust which tend to heal over such products and remain impervious to cleaning by wind or water) has been observed, in the field, to clog due to tendencies to trap and hold debris, thereby channeling water past, rather than into the under lying rain gutter. Sub Heading 4b Filter Membrane Prior art, though naming filtering medium as cloth or screen or tangled mesh, has not recognized or utilized the improvements offered by a filtering membrane accomplished by the intersection of material of equal or larger and smaller wire, or cloth, or plastic thread configurations as is illustrated in FIG. 5 . Filtering and screening methods illustrated in prior art attempted to improve the propensity of reverse-curved or hooded gutter protection systems illustrated in prior art U.S. Pat. No. 5,557,891 to Albracht, and similar inventions, to trap and hold debris within their open channels. When this has occurred, water has flowed past the clogged open channels and to the ground due to waters tendency to bridge over debris trapped in a concave aperture. When debris rests on planar surfaces, water will travel beneath, rather than bridge over them, and attempt to travel through any open-air openings or apertures that exist beneath the debris. Filter and screening methods of gutter protection, however, illustrated in prior art have employed woven or knitted or mesh fibers or wires which intrinsically contain numerous joints, which tend to trap and hold debris. Filtering cloths, screens, and meshes are known to trap and hold debris to protect a medium on the other side of the filter. Screens, too, are known to trap and hold debris. When any of these methods of gutter protection have been employed in prior art, such inventions have been known to trap and hold debris reducing the amount of water that is able to enter an underlying rain gutter regardless of the porosity and/or density of the filter medium. The present invention exhibits no tendency to trap and hold debris, or dirt, or pollen and thereby offers a significant improvement over prior art. The present invention offers an improvement over prior art in that it's filtering membrane 50 , offers far fewer under and over knitted or woven or meshed joints for debris to become lodged within. The present invention also offers improvement over prior art in the existence of a strong water channeling action taking place beneath filtering membrane 50 throughout the structure of filter skeleton 43 . The water adhesive effects, strong siphoning action, and ultimate breaking of the water adhesion and resulting continued downward flow of water into an underlying rain gutter accomplished by the filter configuration illustrated in FIG. 6 offers improvements not found in prior art. Referring again to FIGS. 5 & 6, the present invention also exhibits an ability to clean or wash smaller particles out of the 100 micron openings existing between the interconnected threads or wires it employs. This ability has not been noted in prior art but, rather, prior art is known to clog with debris or cake over with pollen, leached shingle oil, dirt, and other pollutants and has not exhibited an ability to self-clean, found in the present invention. The present invention is an improvement over prior art that employs insertable, or under-affixed, or recessed filters such as is employed and illustrated in U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear and similar prior art because these previous filtration attempts are known to either clog, heal over and become water-proof, and/or channel water forward. Recessed filters beneath a perforated plane such as employed in U.S. Pat. No. 5,595,027 to Vail receive far less water than the present invention due to water adhesion principals that direct water around, rather than through simple perforations. Filtration cloths or membranes resting on top of or sandwiched between screens, perforated planes, or denser filter mediums such as is illustrated in prior art U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 6,134,843 to Tregear and similar devices are also known to allow water channeling to the front lip of a rain gutter due to the unbroken inter-connected supporting or securing structures beneath or surrounding the filtering membrane and also due to the linear, rather than downward, channeling of water such filtering membranes themselves are known to exhibit in the field. REFERENCE NUMERALS IN DRAWINGS 0 perforations 1 extruded body 2 “scorable” top shelf 3 - 4 - 16 top, side, and bottom planes of 2 nd u-channel 5 vertical leg 13 - 16 v-shaped perforated well 6 vertical leg/“water dam” 12 - 7 - 8 bottom-side and top planes of 1 st u-channel 9 - 10 front “lip” of body 17 - 18 - 26 top, side, and bottom planes of 3 rd u-channel 20 reverse curved plane 22 open channel 19 - 20 rear supporting leg 21 pre-scored indentations 23 pre-scored indentation 24 open channel 25 open channel 28 rain gutter 29 rear u-shaped wall of gutter hangar 27 tensioning/securing flange 30 fastening screw 31 filter material 32 filtration membrane 35 “braked” or formed clip on cover 43 filtration skeletal structure 44 rear ledge of skeletal structure 45 “water drops” of equal length 46 termination of “water drops” 47 ellipses 48 width of perforated plane section 50 filter membrane 51 “water drop” of greater length 52 front ledge of skeletal structure 54 vertical leg 57 forward ledge of skeletal structure

An elongated strip of extruded plastics material includes a vertical rear plane adapted to seat on the rear portion of a gutter-hanging bracket. The rear vertical plane integrally connects to a second forward extending plane that joins, by means of an underlying u-shaped channel, a v-shaped perforated third plane that forces water to pool and drop through the perforations. The third plane joins, by means of an underlying u-shaped channel, a flange that projects outwardly for retaining the strip to a gutter. A filter configuration comprised of a debris repelling membrane, overlying a skeletal structure of ellipsoid rods spaced and resting on vertical planes, serves to break the forward flow of water and to channel water onto and through its integral perforated horizontal plane. The filter configuration is readily inserted into the u-shaped channels existing on the forward and rear edges of the v-shaped perforated third plane.

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application claims priority to Korean Patent Application No. 10-2013-0021301 filed on Feb. 27, 2013, the entire contents of which is incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a vacuum pressure forming device of a vehicle and, more particularly, to a vacuum pressure forming device of a vehicle capable of forming a brake vacuum pressure by using an electric supercharger when necessary. [0004] 2. Description of Related Art [0005] In a vehicle, generally, ambient air is introduced into the vehicle, mixed with fuel, and supplied to an engine, and the engine burns the mixture of air and fuel to obtain power required for driving the vehicle. [0006] For combustion in the course of generating power by driving an engine, ambient air must be sufficiently supplied to obtain a desired output and combustion efficiency of the engine. Thus, in order to increase combustion efficiency and enhance an output of an engine, a supercharger or a turbo charger that pressurizes air for combustion and supplies the pressurized air is applied to a vehicle. [0007] The supercharger has a structure compressing air to be supplied to an engine by using pressure of an exhaust gas discharged from the engine. [0008] However, there is a limitation in compressing intake air with only pressure of exhaust gas and supplying the same to an engine according to a running situation of a vehicle, so recently, an electric supercharger that drives a compressor by using an electric motor to compress intake air and supplies the same is applied to a vehicle. [0009] In a vehicle employing the foregoing turbo charger or supercharger, when a driver manipulates a brake pedal in a state in which he or she steps on an accelerator pedal to its maximum level to make an engine enter a wide open throttle (WTO) region, static pressure formed in an intake manifold is not smoothly discharged, failing to form sufficient vacuum pressure for boosting a brake, so the brake is pushed out. [0010] Also, for example, even when a vehicle is run on a high ground, vacuum pressure formed by an intake manifold may not be sufficient for boosting a brake. [0011] The failure of smoothly performing a brake boosting operation due to insufficient vacuum pressure therefore formed by the intake manifold and supplied to a brake device may be vital for a safe operation of a vehicle, and thus, a vacuum pump for sufficiently supplying brake vacuum pressure is installed in a vehicle. [0012] However, an installation of a vacuum pump to form vacuum pressure for brake boosting operation may increase a weight and cost of a vehicle, for which, thus, an improvement method therefore is required. [0013] The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. BRIEF SUMMARY [0014] Various aspects of the present invention are directed to providing a vacuum pressure forming device for a brake of a vehicle having advantages of smoothly forming sufficient brake vacuum pressure by operating an electric supercharger when sufficient brake vacuum pressure for brake boosting operation is not formed in a vehicle employing the electric supercharger. [0015] In an aspect of the present invention, a brake vacuum pressure forming device for a motor vehicle, may include a vacuum chamber supplying a vacuum pressure boosting a break operating force, an electric supercharger connected to the vacuum chamber to supply vacuum pressure thereto, a first vacuum pressure supply path connecting the electric supercharger and the vacuum chamber, and a vacuum pressure control valve mounted on the first vacuum pressure supply path and opening and closing the first vacuum pressure supply path. [0016] The brake vacuum pressure forming device may include a cylinder block forming a combustion chamber, an intake manifold connected to the cylinder block to supply ambient air thereto, a turbo charger compressing ambient air by using pressure of exhaust gas discharged from the combustion chamber and supplying the ambient air to the combustion chamber, an intercooler cooling a compressed air supplied from the turbo charger to the combustion chamber, a first supercharge path connecting the turbo charger and the intercooler, a second supercharge path connecting the intercooler and the intake manifold, an intake path connecting the electric supercharger and the second supercharge path, and an opening and closing valve mounted on the intake path and opening and closing the intake path. [0017] A boost pressure control valve is installed in the second supercharge path and controls the compressed air introduced to the intake manifold through the intercooler. [0018] The intake path is connected to the second supercharge path between the boost pressure control valve and the intercooler. [0019] A recirculation valve is installed in the second supercharge path between the boost pressure control valve and the intake manifold in order to selectively allow the second supercharge path to communicate with the outside. [0020] The vacuum chamber is connected to the intake manifold through a second vacuum pressure supply path. [0021] The opening and closing valve and the vacuum pressure control valve form an integrated valve unit. [0022] The brake vacuum pressure forming device may further include a pressure sensor sensing pressure of the vacuum chamber, and an engine control unit controlling the electric supercharger, the recirculation valve, the vacuum pressure control valve, the opening and closing valve, and the boost pressure control valve according to pressure sensed by the pressure sensor. [0023] The engine control unit controls the vacuum pressure control valve to open the first vacuum pressure supply path when the vacuum pressure sensed by the pressure sensor is equal to or lower than a pre-set value, controls the opening and closing valve to close the intake path, controls the boost pressure control valve to close the second supercharge path, controls the recirculation valve to shut the second supercharge path against the outside, and controls the electric supercharger to be operated. [0024] A pressure sensor sensing boost pressure of the second supercharge path is installed, and when the boost pressure sensed by the pressure sensor is equal to or higher than a target boost pressure, the engine control unit controls the boost pressure control valve and the recirculation valve to be opened. [0025] In the case of the brake vacuum pressure forming device for a motor vehicle according to an embodiment of the present invention, brake vacuum pressure formed by the intake manifold while a vehicle is running is sensed, and when it is determined that the brake vacuum pressure formed by the intake manifold is not sufficient, the electric supercharger is operated to supply brake vacuum pressure to the vacuum chamber configured for supplying brake vacuum pressure. Thus, appropriate brake vacuum pressure is constantly formed while a vehicle is running, thus ensuring safe vehicle operation. [0026] Also, when boost pressure of compressed air supplied to the intake manifold through the turbo charger is increased to be equal to or higher than target boost pressure, the compressed air is appropriately discharged to the outside, effectively preventing surge of the engine. [0027] In addition, there is no need to use a vacuum pump to form brake vacuum pressure, and also, there is no need to install a valve for discharge compressed air to the outside when boost pressure is formed. Also, the configuration of the device is simple, reducing a weight of the vehicle and cost. [0028] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0029] FIG. 1 is a view illustrating a configuration of a vacuum pressure forming device for a brake of a vehicle according to an embodiment of the present invention. [0030] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. [0031] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DETAILED DESCRIPTION [0032] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. [0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. [0034] Referring to FIG. 1 , an intake manifold 20 allowing air or a mixture of air and fuel to be introduced therein is connected to a cylinder block 10 forming a combustion chamber of an engine, and an exhaust manifold 30 for discharging exhaust gas generated after combustion in the combustion chamber from the cylinder block 10 is connected to the cylinder block 10 . [0035] A turbo charger TC is connected to the exhaust manifold 30 and the intake manifold charger 20 , respectively, in order to compress air by using pressure of exhaust gas discharged through the exhaust manifold 30 and supply the compressed air to the intake manifold 20 . [0036] Namely, a turbine constituting the turbo charger TC is connected to the exhaust manifold 30 and an impeller constituting the turbo charger TC is connected to the intake manifold 20 . [0037] Also, an exhaust path 40 is connected to the exhaust manifold 30 in order to induce exhaust gas introduced to the exhaust manifold 30 to the outside. [0038] A catalytic converter is installed in the exhaust path 40 in order to reduce harmful components included in exhaust gas discharged through the exhaust path 40 . The catalytic converter may include a warm-up catalytic converter (WCC) and an under floor catalytic converter (UCC). [0039] A recirculation path 42 is connected to the exhaust path 40 between the two catalytic converters WCC and UCC in order to recirculate a portion of exhaust gas to the cylinder block 10 , and an exhaust gas recirculation cooler 50 is installed in the recirculation path 42 in order to reduce temperature of exhaust gas. [0040] An intake path 52 allowing ambient air to flow thereto is connected to the turbo charger TC, and the recirculation path 42 is connected to the intake path 52 , so the turbo charger TC compresses a portion of exhaust gas and ambient gas and supplies the same to the cylinder block 10 . [0041] In order to control exhaust gas introduced to the intake path 52 through the recirculation path 42 , a control valve 60 is installed in the recirculation path 42 . [0042] An air cleaner 70 filtering foreign materials included in ambient air and a bypass valve 80 are installed in the intake path 52 . [0043] An outlet of the turbo charger TC is connected to the intake manifold 20 through a supercharge path. [0044] An intercooler 90 is installed midway in the supercharge path in order to cool supercharged air discharged after being compressed by the turbo charger TC and supply the same to the intake manifold 20 . [0045] Namely, an outlet of the turbo charger TC and an inlet of the intercooler 90 are connected through a first supercharge path 92 a, and an outlet of the intercooler 90 and the intake manifold 20 are connected through a second supercharge path 92 b. [0046] A boost pressure control valve 100 is installed in the second supercharge path 92 b in order to control supercharged air introduced to the intake manifold 20 through the intercooler 90 . [0047] An electric supercharger 110 is provided to additionally compress compressed air to be supplied to the intake manifold 20 . [0048] An inlet of the electric supercharger 110 is connected to the second supercharge path 92 b between the intercooler 90 and the boost pressure control valve 100 through the intake path 112 , and an outlet of the electric supercharger 110 is connected to the second supercharge path 92 b between the boost pressure control valve 100 and the intake manifold 20 through a discharge path 114 . [0049] A vacuum chamber 120 is connected to the intake path 112 through a first vacuum pressure supply path 122 , and the vacuum chamber 120 is connected to the intake manifold 20 through a second vacuum pressure supply path 124 . [0050] Also, the vacuum chamber 120 is connected to a brake booster 130 boosting upon receiving operating force from a brake pedal. Thus, when the brake booster 130 performs a boosting operation, pressure of the vacuum chamber 120 acts as vacuum pressure. [0051] In order to control vacuum pressure supplied to the vacuum chamber 120 through the first vacuum pressure supply path 122 , a vacuum pressure control valve 140 is installed in the first vacuum pressure supply path 122 . An opening and closing valve 150 is installed in the intake path 112 to open and close the intake path 112 . The vacuum pressure control valve 140 and the opening and closing valve 150 may be integrated to be configured as a valve unit. [0052] A recirculation valve RCV is installed as an air vent valve in the second supercharge path 92 b between the boost pressure control valve 100 and the intake manifold 20 in order to selectively discharge compressed air from the second supercharge path 92 b to the outside. [0053] The recirculation valve RCV also serves to prevent surge of the engine. [0054] A pressure sensor 160 is installed in the intake manifold 20 , the second vacuum pressure supply path 124 , or the vacuum chamber 120 in order to sense vacuum pressure of the vacuum chamber 120 . The pressure sensor 160 is also installed in the second supercharge path 92 b in order to sense boost pressure formed in the second supercharge path 92 b. [0055] Also, the pressure sensor 160 is connected to an input terminal of an engine control unit (ECU) so that a pressure signal sensed by the pressure sensor 160 is input to an electronic control unit or the engine control unit (ECU). [0056] The electric supercharger 110 , the recirculation valve RCV, the boost pressure control valve 100 , the opening and closing valve 120 , and the vacuum pressure control valve 140 are connected to an output terminal of the ECU, and operations thereof are controlled according to a control signal from the ECU. [0057] Vacuum pressure generated by the intake manifold 20 while a vehicle is running acts on the vacuum chamber 120 through the second vacuum pressure supply path 124 to form vacuum pressure in the vacuum chamber 120 , and power assistance is formed by using the vacuum pressure formed in the vacuum chamber 120 when the brake booster 130 performs a braking operation, thus allowing for a smooth braking operation. [0058] While a vehicle is running, the ECU senses vacuum pressure generated in intake manifold 20 or the second vacuum pressure supply path 124 by the medium of the pressure sensor 160 . When the ECU determines that the sensed vacuum pressure is not sufficient for a brake boosting operation, the ECU operates the electric supercharger 110 (M:ON) to supply vacuum pressure to the vacuum chamber 120 . [0059] Namely, the ECU compares the sensed vacuum pressure with a pre-set value, and when the sensed vacuum pressure is equal to or lower than the pre-set value, the ECU applies an operation signal to the electric supercharger 110 to operate the electric supercharger 110 . [0060] The ECU applies a control signal to the vacuum pressure control valve 140 to open the first vacuum pressure supply path 122 , the opening and closing valve 150 is turned off to shut the intake path 112 , the boost pressure control valve 100 is turned off to shut the second supercharge path 92 b, and the recirculation valve RCV is turned off to shut the second supercharge path 92 b against the outside. [0061] According to an operation of the electric supercharger 110 , vacuum pressure is formed in an inlet of the electric supercharger 110 , and the generated vacuum pressure acts on the vacuum chamber 120 through the vacuum pressure control valve 140 an the first vacuum pressure supply path 122 to form appropriate vacuum pressure in the vacuum chamber 120 . [0062] Accordingly, the brake booster 130 performs a boosting operation by using the appropriate vacuum pressure formed in the vacuum chamber 120 , performing a normal braking operation. [0063] Meanwhile, positive pressure is formed in a discharge opening of the electric supercharger 110 , which should be appropriately discharged to the outside. To this end, the ECU applies a control signal to the recirculation valve RCV to open it, whereby compressed air present in the second supercharge path 92 b is released to the outside through the recirculation valve RCV, appropriately resolving the positive pressure. [0064] Also, the ECU senses boost pressure in the second boost pressure supply path 92 b by the medium of the pressure sensor 160 , and determines whether the boost pressure in the second boost pressure supply path 92 b has been excessively increased due to the operation of the turbo charger TC and the OFF operation of the boost pressure control valve 100 . [0065] When the boost pressure is higher than a target boost pressure, the ECU applies a control signal to the boost pressure control valve 100 to control the boost pressure control valve 100 to open the second supercharge path 92 b, and also applies a control signal to the recirculation valve (RCV) to open it, whereby the compressed air in the second supercharge path 92 b is released to the outside through the recirculation valve (RCV), resolving excessive boost pressure. [0066] As described above, when it is determined that intake vacuum pressure generated by the intake manifold 20 is not sufficient, the electric supercharger 110 is operated to supplement brake vacuum pressure, and when intake vacuum pressure is sufficient, intake vacuum pressure of the intake manifold 20 is appropriately used. Thus, there is no need to install a vacuum pump to supplement brake vacuum pressure. [0067] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.

A brake vacuum pressure forming device for a motor vehicle may include a vacuum chamber supplying a vacuum pressure boosting a break operating force, an electric supercharger connected to the vacuum chamber to supply vacuum pressure thereto, a first vacuum pressure supply path connecting the electric supercharger and the vacuum chamber, and a vacuum pressure control valve mounted on the first vacuum pressure supply path and opening and closing the first vacuum pressure supply path.

CROSS-REFERENCE TO PRIOR APPLICATION [0001] Priority is claimed to Russian Patent Application No. RU 2011127161, filed on Jul. 1, 2011, the entire disclosure of which is hereby incorporated by reference herein. FIELD [0002] The present invention relates to a stator for a turbine, in particular for a gas turbine. The invention further relates to a turbine comprising such a stator as well as a vane of such a stator. BACKGROUND [0003] A stator is an essential component of a turbine, wherein the stator comprises vanes guiding a driving fluid of the turbine onto blades of a rotor of the turbine thereby leading to a rotation of the blades and thus the rotor. The rotation axis of the rotor defines an axial direction. A radial direction and a circumferential direction are each defined in relation to the axial direction. The vanes of the stator are arranged in rows, wherein each row usually comprises circumferentially neighbouring vanes. Said vanes usually comprise an airfoil being arranged on an inner diameter platform of the vane and at the inner end of the airfoil, wherein the term inner is defined with respect to the radial direction. [0004] In the case of a gas turbine the driving fluid is an expanding gas, wherein the expansion is achieved by the combustion of said gas. Therefore the vanes of the stator are exposed to high temperatures, which results in a high thermodynamic stress of the vanes. In order to reduce said stress vanes usually comprise a channel system for cooling the vane with cooling gas thereby using said cooling gas to also cool the inner diameter platform, that is, the channel system is connected to a cavity of the inner diameter platform, wherein said inner diameter platform cavity is, in particular, delimited by side walls of the corresponding inner diameter platform. The term, ‘side wall’, is thereby defined with respect to the circumferential direction, wherein the side walls of the inner diameter platform each face a side wall of the inner diameter platform of a circumferentially neighbouring vane. Considering the arrangement of the vanes of the stator, this leads to a gap between the facing side walls. SUMMARY [0005] In an embodiment, the present invention provides a stator for a turbine having an arrangement of vanes including at least a first vane and a second vane circumferentially neighbouring the first vane. Each of the first vane and the second vane include: an airfoil; a channel system configured to cool the respective vane with cooling gas; and an inner diameter platform disposed at an inner end of the airfoil, the inner diameter platform including an inner diameter platform cavity and at least one circumferentially arranged side wall which delimits the inner diameter platform cavity, the inner diameter platform cavity being connected with the channel system so as to feed the cooling gas to the inner diameter platform. At least one sealing plate is disposed between the at least one circumferentially arranged side wall of the first vane and the at least one circumferentially arranged side wall of the second vane, the at least one circumferentially arranged side walls of the first vane and the second vane facing one another, so as to form an intermediate cavity that is fluidically separated from the inner diameter platform cavities. BRIEF DESCRIPTION OF THE DRAWINGS [0006] The present invention will be described in even greater detail below based on the exemplary figures, which are schematic. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following: [0007] FIG. 1 shows a perspective view of a vane inner platform; [0008] FIG. 2 shows a longitudinal section view of a turbine; and [0009] FIG. 3 shows a cross section of a vane inner platform. DETAILED DESCRIPTION [0010] In an embodiment, the present invention solves the problem of delivering an improved or at least alternative embodiment for a stator of the above kind, which has improved sealing. [0011] In an embodiment, the present invention forms an intermediate cavity between side walls of inner diameter platforms of circumferentially neighbouring vanes of a stator by making use of a gap between said side walls, wherein the inner diameter platform of a vane is arranged at the inner end of an airfoil of the corresponding vane and the side wall of the inner diameter platform is facing the side wall of the inner diameter platform of a circumferentially neighbouring vane with the side walls delimiting an inner diameter platform cavity of the corresponding inner diameter platform. The vanes moreover each comprise a channel system for cooling the respective vane with cooling gas, wherein the inner diameter platform cavity is connected to the channel system and thus cooled with said cooling gas and the intermediate cavity is fluidically separated from the respective inner diameter platform cavities, in particular by means of the side walls. The intermediate cavity between the circumferentially neighbouring inner diameter platforms thereby in particular interrupts or at least reduces a leakage of a driving fluid of the turbine into the gap between the side walls. The circumferential direction being in relation to a rotational axis of a rotor of a corresponding turbine the stator is assembled in. A radial direction can be respectively defined in relation to the rotational axis. [0012] According to the invention, an embodiment comprises a gap between the facing side walls of two circumferentially neighbouring vanes. This gap is now enclosed by at least one sealing plate to form the intermediate cavity. Said intermediate cavity is thus delimited by the side wall in the circumferential direction and enclosed by the sealing plate/plates. The intermediate cavity is therefore separated and thus fluidically isolated form the inner diameter platform cavity of the corresponding inner diameter platforms. This arrangement of the sealing plates in particular leads to an improved sealing of the intermediate cavity. [0013] According to a preferred embodiment at least one of the inner diameter platforms comprising the side wall forming the intermediate cavity, comprises at least one groove in the region of the intermediate cavity. The groove is thereby constructed around the intermediate cavity, i.e. the groove encloses the intermediate cavity. In the case where several grooves are provided, these grooves are preferably arranged around the intermediate cavity and in particular distributed in a homogeneous or continuous manner. The grooves are thus constructed as groove sections running around the intermediate cavity. Said groove/grooves are further adapted for receiving at least one sealing plate enclosing the intermediate cavity. The sealing plate is hence arranged within said groove, wherein the groove and thus the sealing plate extend around the intermediate cavity. Therefore the groove/grooves can be constructed within the side walls of the respective inner diameter platforms. In a preferred embodiment two platforms each comprise one side wall forming the intermediate cavity, wherein said side walls each comprise grooves for receiving at least one sealing plate. The grooves of said inner diameter platforms thereby comprise a complementary arrangement and/or shape. That is, in particular, the grooves of the respective inner diameter platforms can be shaped and constructed similarly and arranged directly opposite each other. They can also be constructed differently and an enclosed sealing can be ensured by the arrangement of the sealing plates. In the case where several grooves are provided in each inner diameter platform, i.e. where there are groove sections, the sections in neighbouring platforms can be arranged to face each other, that is, the groove sections of the inner diameter platforms are in particular arranged in the same manner. The groove sections can also be displaced with respect to each other, that is, they may be arranged in different ways. In the latter case a preferred embodiment is one, which provides at least one groove section around any part of an intermediate cavity region. It shall be mentioned that it is also possible to arrange the sealing plates such that they overlap. This overlap can be realised both by means of facing sealing plates and/or be means of neighbouring sealing plates arranged within the groove/grooves of one of the inner diameter platforms. [0014] It is understood, that the sealing plates comprise a complementary shape and arrangement to the respective grooves. That is, the sealing plates are in particular constructed to fit and fill the corresponding groove/grooves. The respective conditions within the turbine thereby require respective properties of the sealing plates, for instance, heat resistance. Therefore metals and alloys are preferred materials of the sealing plates. [0015] According to a further preferred embodiment the sealing plate/plates form a peripheral seal of the intermediate cavity. That is in particular, the sealing plate/plates encircle the intermediate cavity thereby completely or at least substantially sealing the intermediate cavity along the respective direction. A complete or at least substantial sealing of the intermediate cavity is thus given by the side walls and the sealing plate/plates, wherein the sealing plate/plates contact the corresponding inner diameter platforms, in particular in the region of the groove/grooves. [0016] According to a particularly preferred embodiment the two facing side walls each comprise a groove, wherein said grooves are similarly shaped and arranged within the respective side walls in a symmetric manner. In this embodiment two sealing plates are arranged within these grooves. One of the sealing plates is arranged at the bottom side of the respective inner diameter platform with the bottom side opposing the airfoil. Said sealing plates contact each other at the ends of the respective sealing plates. The latter sealing plate is arranged within the remaining groove area, i.e. in particular, said sealing plate runs from a back side of the intermediated cavity to its top side adjacent to the airfoil and continues to a front side of the intermediate cavity to contact the first sealing plate by means of the ends of the respective sealing plates. The front side and the back side are thereby defined with respect to a flow direction of the driving fluid of the turbine. In that sense, the front side is the upstream side and the back side is the downstream side. [0017] The peripheral sealing of the intermediate cavity comprises at least one opening according to a further embodiment. Said opening can thereby be realised by means of a cut-out within the respective sealing plate/plates and/or an interruption within the respective sealing plate/plates. The opening is thereby preferably arranged on the bottom side of the intermediate cavity, i.e. the opening is constructed within the side of the sealing opposing the airfoil. Said opening is moreover preferably arranged on the front side of the intermediate cavity, i.e. on the upstream side of the intermediate cavity. The opening now serves in particular as an inlet for a pressurized gas. That is, the intermediate cavity is pressurized by means of the pressurized gas pumped into the intermediate cavity via said opening. The pressurisation of the intermediate cavity in particular aims to improve the sealing of the intermediate cavity by preventing the driving fluid of the turbine from entering the intermediate cavity. [0018] According to a preferred embodiment, said opening is fluidically separated from the channel system of the respective vane. In other words, the opening of the intermediate cavity is fluidically isolated form the channel system used for cooling the vane and in particular the inner diameter platform by means of the inner diameter platform cavity. That is, the opening of the intermediate cavity is fluidically disconnected from the inner diameter platform cavity preserving the separation between both said cavities. Thus the charge gas and the cooling gas can run through different gas supply devices of the turbine and can moreover be different. [0019] In a further embodiment, the vane comprises an outer diameter platform, wherein the outer diameter platform is arranged at the outer end of the airfoil of the vane with the outer end referring to the radial direction. That is the outer diameter platform is arranged at the end of the airfoil opposing the end connected to the inner diameter platform. The outer diameter platform further comprises an outer diameter platform cavity, which is connected to the channel system. The outer diameter platform moreover preferably comprises a cooling gas inlet to introduce the cooling gas into the outer diameter platform cavity. Hence, said cooling gas is used to cool the outer diameter platform and the inner diameter platform. Therefore the channel system runs through the airfoil, in particular by means of at least one channel, wherein said channel preferably runs from the outer diameter platform to the inner diameter platform and/or vice versa. Thus said cooling gas also cools the airfoil. Therefore the construction is simplified in order to provide pressurised gas for pressurising the intermediate cavity on the one hand an to provide cooling gas for cooling the outer diameter platform, the airfoil and the inner diameter platform on the other hand. [0020] It shall be mentioned, that the opening of the intermediate cavity can have an arbitrary size and shape. However, a symmetric shape, such as a circular shape is favoured, wherein said circular opening is preferably arranged on the front side of the intermediate cavity and thus on the upstream side of the vane and opposes the airfoil, i.e. the opening is arranged within the bottom side of the intermediate cavity. The size of the opening thereby does not exceed the width of the intermediate cavity in the respective region in order to maintain the fluidic separation between the intermediate cavity and the neighbouring inner diameter platform cavities. [0021] According to a further embodiment the groove of the inner diameter platform comprises at least one interruption, wherein the interruption is arranged at the opening of the intermediate cavity. Said interruption is thus aligned with or aligned facing said opening and preferably arranged on the bottom side of the corresponding inner diameter platform. In the case of several grooves, these grooves are preferably arranged in a symmetrical manner to be facing and/or enclosing said opening. In the case of grooves within both inner diameter platforms forming the intermediate cavity, said grooves also comprise symmetrically arranged interruptions aligned with or facing the opening. [0022] In order to ensure a reasonable sealing between the vane and a vane carrier, the vane comprises a sealing at the bottom plate of the inner diameter platform. Said sealing is thus arranged on the side of the inner diameter platform opposing the airfoil and projects radially inwards. An example for such a sealing is a ring shaped seal, in particular a Del Matto seal, as disclosed for example in U.S. Pat. No. 4,050,702, the disclosure to which is herewith incorporated to the present disclosure by reference. [0023] According to a further embodiment the inner diameter platform comprises at least one gas outlet, wherein said gas outlet is in particular arranged within the top plate of the inner diameter platform. The gas outlets are thus in particular arranged on the side of the inner diameter platform facing the airfoil. Said gas outlets thereby penetrate through the respective wall of the inner diameter platform to provide outlets for the cooling gas from the inner diameter platform cavity. The gas outlets are therefore preferably arranged on the downstream side of the inner diameter platform and can thus also be arranged within/at the front side of the inner diameter platform. [0024] As the vanes and the inner diameter platforms are an important part of an embodiment of the invention, it is understood, that a single vane used in a stator according to an embodiment of the invention also falls under the scope of the invention. [0025] It is understood, that the idea of the intermediate cavity can also be realised between a vane comprising an inner diameter platform and an inner diameter platform cavity and a vane without an inner diameter platform cavity as well as between a vane comprising an inner diameter platform and an inner diameter platform cavity and a vane without an inner diameter platform. Combinations thereof are also adapted for the implementation of the intermediate cavity. These variations thus also belong to the scope of the invention. [0026] According to a further aspect of the invention a turbine, in particular a gas turbine comprises a stator according to an embodiment of the invention. Said turbine is in particular characterised by an improved efficiency in particular by means of the improved sealing of the stator. [0027] It is understood that the aforementioned features and the features to be mentioned hereafter are applicable not only in the given combination, but also in other combinations as well as separated without departing from the scope of the invention. [0028] The above and other features and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings. [0029] Referring to FIG. 1 to FIG. 3 a vane 1 comprises an airfoil 2 and a platform 3 , wherein the platform 3 carries the airfoil 2 on its top plate 4 and at the inner end of the airfoil 2 . The term, ‘top’, thereby is in relation to a radial direction depicted by the arrow 5 which in turn is in relation to an axial direction of the rotation of a rotor 6 of a turbine 7 illustrated by the arrow 8 , wherein the turbine 7 comprises a stator 9 comprising the shown vane 1 . [0030] As shown in FIG. 1 the top plate 4 has a flat portion and then bends towards a bottom plate 10 of the inner diameter platform 3 and contacts the bottom plate 10 with an acute angle at an upstream side of the inner diameter platform 3 , wherein the upstream side or the front side is defined with respect to a flow direction of a driving fluid flowing through the turbine 7 and depicted by the arrow 11 . The airfoil 2 comprises holes 12 arranged in radially running rows along the airfoil 2 . These holes serve as outlets for a cooling gas flowing through the airfoil 2 by means of channels of a channel system. The channel system is connected to an inner diameter platform cavity 13 of the inner diameter platform 3 , wherein said inner diameter platform cavity 13 is formed by the top plate 4 , the bottom plate 10 , a back wall 14 and side walls 15 of the inner diameter platform 3 . The back wall 14 is thereby the wall on the downstream side of the inner diameter platform 3 . The side walls 15 extend in the axial and radial directions and delimit the inner diameter platform cavity 13 in a circumferential direction given by the arrow 16 and defined in relation to the rotational axis of the turbine 7 given by the arrow 8 . The top plate 4 of the inner diameter platform 3 comprises gas outlets 17 distributed along rows over the top plate 4 and connected to the inner diameter platform cavity 13 . There are further holes 12 within the front area of the inner diameter platform 3 connected to the inner diameter platform cavity 13 and also serving as outlets for the cooling gas. The further holes 12 within the front area of the inner diameter platform 3 face in the axial or flow direction. [0031] The side wall 15 of the vane 1 comprises a groove 18 . Said groove 18 starts at the front side of the inner diameter platform 3 and runs along and, in particular, follows the contour of the top plate 4 . The groove 18 continues to run along the back wall 14 and follows the contour of the curved transition between the top plate 4 and the back wall 14 of the inner diameter platform 3 . The groove 18 continues along the bottom plate 10 of the inner diameter platform 3 with a right-angled transition and stops at position spaced from the front side of the inner diameter platform 3 . That is, the groove 18 comprises an interruption 19 within the bottom plate 10 region and on the front side, and thus the upstream side, of the inner diameter platform 3 . A first sealing plate 20 is arranged within the groove 18 running in the region along the top plate 4 and the back wall 14 . Said sealing plate 20 thus comprises shape which is complementary to this region of the groove 18 . The sealing plate 20 is therefore shaped with a curved transition in the transition region between the top plate 4 and the back wall 14 . A second sealing plate 21 is arranged within the region of the groove 18 running along the bottom plate 10 , wherein said sealing plate 21 contacts the first sealing plate 20 in the right angled transition region of the groove 18 and thus on the downstream side of the inner diameter platform 3 . The second sealing plate 21 comprises a flat shape and fills the whole remaining groove 18 region, i.e. in particular it extends to the edge of the interruption 19 . Both sealing plates 20 , 21 thereby project away from the side wall 18 and thus towards the side wall 18 of the inner diameter platform 3 of a circumferentially neighbouring vane 1 . These plates 20 , 21 are therefore adapted to be arranged within the grooves of the facing side walls 15 of adjacent inner diameter platforms 3 . The groove 18 of the facing inner diameter platform 3 has a complementary form, i.e. in particular a complementary interruption, to the opposing groove 18 , leading to the formation of an intermediate cavity 22 between the facing side walls 15 . Said intermediate cavity 22 is thereby delimited by the facing side walls 15 of the circumferentially neighbouring vanes 1 and by the sealing plates 20 , 21 , as shown in FIG. 3 . The sealing plates 20 , 21 thus form a peripheral sealing of the intermediate cavity 22 . The respective interruptions 19 of the corresponding grooves 18 further provide an opening 23 within the peripheral sealing with the said opening being arranged on the bottom side of the cavity, i.e. the side opposing the airfoil 3 , and on the upstream side of the vanes 1 . The alignment and symmetric arrangement of the interruptions 19 thereby leads to a symmetric and, in particular, a rectangular or circular shape of the opening 23 . [0032] The shown vane 1 further comprises a Del Matto sealing 24 connected to the bottom plate 10 of the inner diameter platform 3 within the centre region of the bottom plate and projecting radially inwards, i.e. in the opposite direction to the arrow 5 . The vane further comprises a sealing part 25 also connected to the bottom plate 10 and projecting radially inwards, but arranged on the downstream side of the inner diameter platform 3 . Said sealing part 25 comprises a stepped shape and is adapted to form a labyrinth sealing 26 with fins 27 of a downstream neighbouring blade 28 of the rotor 6 of the turbine 7 , as shown in FIG. 2 . FIG. 2 also shows an outer diameter platform 29 of the vane 1 arranged at the outer end of the airfoil 2 with respect to the radial direction given by the arrow 5 . Thus, the inner diameter platform 3 is arranged at the inner end of the airfoil 2 while the outer diameter platform 29 is arranged at the outer end of the airfoil 2 . The outer diameter platform 29 moreover comprises an outer diameter platform cavity 30 connected to a cooling gas supply device 31 by means of a gas inlet 32 of the outer diameter platform 29 . [0033] FIG. 3 shows a cross section through the stator 9 of the turbine 7 , with the cross section taken through the line E in FIG. 2 . An inner diameter platform cavity 13 of a vane 1 is seen in the lower centre region. The side walls 15 of said inner diameter platform cavity 13 are facing the side walls 15 of circumferentially neighbouring inner diameter platform cavities 13 . Intermediate cavities 22 are arranged on both sides of the centre inner diameter platform cavity 13 , wherein said intermediate cavities 22 are delimited by side walls 15 of the respective adjacent inner diameter platforms 3 and by sealing plates 20 , 21 arranged within symmetrically constructed grooves 18 of the respective adjacent inner diameter platforms 3 . [0034] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. LIST OF REFERENCE NUMERALS [0000] 1 Vane 2 Airfoil 3 Inner diameter platform 4 Top plate 5 Arrow depicting the radial direction 6 Rotor 7 Turbine 8 Arrow depicting the axial direction 9 Stator 10 Bottom plate 11 Arrow depicting the driving fluid direction 12 Hole 13 Inner diameter platform cavity 14 Back wall 15 Side wall 16 Arrow depicting the circumferential direction 17 Gas outlet 18 Groove 19 Interruption 20 Sealing plate 21 Sealing plate 22 Intermediate cavity 23 Opening 24 Del Matto sealing 25 Sealing part 26 Labyrinth sealing 27 Fin 28 Blade 29 Outer diameter platform 30 Outer diameter cavity 31 Cooling gas supply device 32 Gas inlet

A stator for a turbine includes an arrangement of vanes including at least a first vane and a second vane circumferentially neighbouring the first vane. Each of the first vane and the second vane include: an airfoil; a channel system configured to cool the respective vane with cooling gas; and an inner diameter platform disposed at an inner end of the airfoil, the inner diameter platform including an inner diameter platform cavity and a circumferentially arranged side wall which delimits the inner diameter platform cavity, the inner diameter platform cavity being connected with the channel system so as to feed the cooling gas to the inner diameter platform. At least one sealing plate is disposed between the circumferentially arranged side walls of the first vane and the second vane so as to form an intermediate cavity that is fluidically separated from the inner diameter platform cavities.

BACKGROUND OF THE INVENTION The present invention relates to a refrigeration suction mechanism for a piston type compressor. The refrigeration suction mechanism according to the present invention comprises a rotary valve which has a refrigerant introducing passage communicating with a passage extending through a rotary shaft to introduce refrigerant into a compression chamber within a cylinder bore. A piston type compressor has a plurality of pistons each disposed in a cylinder bore in the circumference of a rotary shaft, so as to convert a rotation of the rotary shaft into reciprocating linear motion of the pistons through a cam. Piston type compressors disclosed in Japanese Laid-Open Patent Publication 5-113174 and Japanese Laid-Open Patent Publication 7-63165 comprise a rotary valve for introducing refrigerant into the cylinder bores. A variable discharge swash plate type compressor disclosed in Japanese Laid-Open Patent Publication 5-113174 comprises a rotary valve which is separately formed from and connected to a rotary shaft. The rotary valve is rotatably contained in a valve chamber so as to allow rotational motion of the rotary shaft. Japanese Laid-Open Patent Publication 7-63165 discloses a swash plate type compressor using double-headed pistons. The compressor has a suction passage radially extending in a journal portion of a rotary shaft and communicating with a refrigerant passage extending through the rotary shaft. The suction passage communicates with a suction port of one of cylinders that is in suction stroke as the suction passage rotates. In other words, the rotary shaft acts as a rotary valve. The suction port disclosed in the above publications is selectively opened by the rotary valve to introduce refrigerant into the cylinder bore. This improves volume efficiency compared to the compressor with a suction port selectively opened by a suction valve that can be distorted. However in any of the compressors disclosed in the above publications, refrigerant contained in a cylinder bore which is in suction stroke is inclined to leak from the suction passage along the outer surface of the rotary valve. More specifically, while the compressor disclosed in Japanese Laid-Open Patent Publication 5-113174 preferred to have a least possible gap between the inner surface of the valve chamber and the outer surface of the rotary valve in order to minimize refrigerant leakage, manufacture of such is very difficult. The compressor disclosed in Japanese Laid-Open Patent Publication 7-63165 has a similar problem with respect to a gap between the through hole provided in a cylinder block and the outer surface of the rotary valve. Such leakage of the refrigerant lowered the volume efficiency of the compressor. BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to improve volume efficiency in a piston type compressor using a rotary valve. In order to achieve the above objectives, the present invention provides a refrigeration suction mechanism used in a piston type compressor, wherein a cam member mounted on a rotary shaft for the integral rotation with the rotary shaft converts a rotation of the rotary shaft to a linear reciprocating movement of pistons in cylinder bores arranged around the rotary shaft, wherein a compression chamber is defined in each of the cylinder bores by the associated piston, and wherein refrigerant is introduced to, compressed in and discharged from the compression chamber when the piston is in a suction stroke, a compressing stroke and a discharge stroke respectively, said compressor having a refrigerant passage for allowing the refrigerant to flow toward the compression chamber, said mechanism comprising: a rotary valve integrally formed with the rotary shaft, said rotary valve including an introducing passage that is in communication with the refrigerant passage; a suction passage having a first end and a second end , said first end being connected to each cylinder bore, and said second end being selectively connected to and disconnected from the introducing passage in accordance with the rotation of the rotary valve; a means for transmitting a reaction force acting on the piston to the rotary valve, wherein said reaction force is generated in the compression chamber when the piston is in the discharge stroke, whereby the rotary valve is urged against the second end of the suction passage connected to the cylinder bore. Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: FIG. 1 is a cross sectional side view showing a compressor according to the first embodiment of the present invention. FIG. 2A is a cross sectional view taken along a line 2 A— 2 A in FIG. 1 . FIG. 2B is an enlarged cross sectional side view of a part of a refrigerant passage shown in FIG. 2 A. FIG. 3A is a cross sectional view taken along a line 3 A— 3 Ain FIG. 1 . FIG. 3B is an enlarged cross sectional view of a part of a refrigerant passage shown in FIG. 3 A. FIG. 4 is an enlarged cross sectional view showing a front end portion of the rotary shaft. FIG. 5 is an enlarged cross sectional view showing a rear end portion of the rotary shaft. FIG. 6A is a cross sectional side view showing a compressor according to a second embodiment of the present invention. FIG. 6B is an enlarged cross sectional side view showing a rotary valve partially taken from FIG. 6 B. FIG. 7 is a cross sectional view taken along a line 7 — 7 in FIG. 6 A. FIG. 8 shows a cross sectional view taken along a line 8 — 8 in FIG. 6 A. FIG. 9 is a cross sectional side view showing a compressor according to the third embodiment of the present invention. FIG. 10 is a cross sectional view taken along a line 10 — 10 in FIG. 9 . FIG. 11 is a cross sectional view taken along a line 11 — 11 in FIG. 9 . FIG. 12A is a cross sectional view showing a double-headed piston according to another embodiment. FIG. 12B is a cross sectional view showing a single-headed piston according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention is described by referring to FIGS. 1 through 5 . The first embodiment relates to a fixed-discharge compressor comprising a double headed piston. As shown in FIG. 1 , a front housing 13 and a rear housing 14 are respectively connected to cylinder blocks 11 and 12 , which are connected to each other. A discharge chamber 131 is defined within a front housing 13 . A discharge chamber 141 and a suction chamber 142 are defined in a rear housing 14 . In the front portion of the compressor, a valve plate 15 , a valve forming plate 16 and a retainer forming plate 17 are interposed between the cylinder block 11 and the front housing 13 . A valve plate 18 , a valve forming plate 19 and a retainer forming plate 20 are interposed between the cylinder block 12 and the rear housing 14 . Discharge ports 151 and 181 are respectively formed in the valve plates 15 and 18 . Discharge valves 161 and 191 are respectively formed in the valve forming plates 16 and 19 . The discharge valve 161 selectively opens the discharge port 151 . A retainer 171 regulates an opening size of the discharge valve 161 . Likewise, in the rear portion of the compressor, a valve plate assembly having a discharge port 181 and a discharge valve 191 is disposed between the cylinder block 12 and a rear housing 14 . The discharge valve 191 selectively opens the discharge port 181 . A retainer 201 regulates an opening size of the discharge valve 191 . A rotary shaft 21 is rotatably supported in cylinder blocks 11 and 12 . The rotary shaft 21 is passed through holes 112 and 122 that are formed through cylinder blocks 11 and 12 . The rotary shaft 21 is directly supported by the cylinder blocks 11 and 12 at the positions of the through holes 112 and 122 . A shaft seal 22 is interposed between front housing 13 and rotary shaft 21 . A swash plate 23 , which acts as a cam member comprising aluminum (including aluminum alloy), is mounted on the rotary shaft 21 in a swash plate chamber 24 that is defined between the cylinder blocks 11 and 12 . The swash plate 23 has a plate-shaped portion 235 for slidably contacting shoes 301 and 302 . An angle (swash plate tilt angle) between the plate-shaped portion 235 and a plane orthogonal to an axle 211 of the rotary shaft is fixed. A pair of thrust bearings 25 , 26 are respectively interposed between edges of the cylinder blocks 11 , 12 and both sides of a circular base portion 231 of the swash plate 23 . The swash plate 23 is interposed between a pair of the thrust bearings 25 and 26 so that the swash plate 23 and the rotary shaft 21 which is fixed to the swash plate 23 are adjusted with respect to a relative movement in the direction of the axis 211 of the rotary shaft 21 . As shown in FIG. 4 , the thrust bearing 25 includes a pair of races 251 and 252 and a plurality of rollers 253 disposed therebetween. A projection 111 is formed in an edge surface of the cylinder block 11 . The race 251 abuts the projection 111 . The race 252 of the thrust bearing 25 contacts an end surface 232 of a base portion 231 of the swash plate 23 . When a thrust bearing 25 is observed from one end to the other end with respect to the rotary shaft 21 , an area in which the projection 111 and the race 251 contact and an area in which the end surface 232 and the race 252 contact substantially overlap. Accordingly, the races 251 and 252 are not distorted by a thrust loading. Therefore, the thrust bearing 25 is not provided with a function to absorb the thrust loading. A thrust bearing 26 includes a pair of races 261 and 262 and a plurality of rollers 263 disposed therebetween as shown in FIG. 5. A projection 121 is formed on an end surface of cylinder block 12 . The race 261 abuts the projection 121 . A projection 234 is formed in an edge surface 233 of the base portion 231 of a swash plate 23 . The race 262 abuts the projection 234 . The distance between the rotary shaft 21 and a point at which the projection 234 and the race 262 abuts is longer than the distance between the rotary shaft 21 and the point at which the projection 121 and the race 261 abuts. When the thrust bearing 26 is observed from one end to the other end with respect to the rotary shaft 21 , an area in which the projection 121 and the race 261 contacts and an area at which the projection 234 and the race 262 contacts do not overlap. Accordingly, the races 261 and 262 are distorted by a thrust loading. Therefore, thrust bearing 26 is provided with a function to absorb thrust loading. A plurality of cylinder bores 27 and 27 A are formed in cylinder block 11 to be angularly spaced from one another in a circumference of the rotary shaft 21 as shown in FIG. 2 A. Likewise, a plurality of cylinder bore 28 , 28 A and 28 B are formed in cylinder block 12 to be angularly spaced from one another in a circumference of the rotary shaft 21 as shown in FIG. 3 A. The cylinder bores 27 and 27 A are opposed to the cylinder bores 28 , 28 B and 28 A respectively to accommodate double-headed pistons 29 and 29 A. The rotation of the swash plate 23 , which rotates integrally with the rotary shaft 21 , is transmitted to each of the double-headed pistons 29 and 29 A through shoes 301 and 302 so as to linearly reciprocate the double-headed piston 29 and 29 A within the associated cylinder bore 27 , 27 A, 28 , 28 B and 28 A. Compression chambers 271 and 281 are defined in the cylinder bores 27 , 27 A, 28 , 28 B and 28 A. Through holes 112 and 122 are formed respectively in the cylinder blocks 11 and 12 for allowing the rotary shaft 21 extending therethrough. Each of the through holes 112 and 122 extend with the different radii along the longitudinal direction of the rotary shaft 21 . Sealing surfaces 113 and 123 are formed in contact with the rotary shaft 21 in a portion in which the through hole has the smallest radius. The rotary shaft 21 is directly supported by cylinder blocks 11 and 12 on the sealing surfaces 113 and 123 . A passage 212 is formed through the rotary shaft 21 . An end of the passage 212 is in inside edge of the rotary shaft 21 and opens into the suction chamber 142 defined within the rear housing 14 . Introducing passages 31 and 32 are respectively formed within the rotary shaft 21 in fluid communication with the passage 212 . Suction passages 33 and 33 A are formed in the cylinder block 11 to allow cylinder bores 27 and 27 A to be in communication with the through hole 112 as shown in FIGS. 2A , 2 B and 4 . A mouth 331 of suction passages 33 and 33 A opens on a sealing surface 113 . Suction passages 34 and 34 A are formed in the cylinder block 12 to communicate cylinder bores 28 , 28 B and 28 A with hole 122 as shown in FIGS. 3A , 3 B and 5 . A mouth 341 of suction passages 34 and 34 A opens in a sealing surface 123 . Ends 311 and 321 of the introducing passage 31 and 32 intermittently communicate with the mouths 331 and 231 of suction passages 33 , 33 A, 34 and 34 A in conjunction with the rotation of the rotary shaft 21 . An end 311 of an introducing passage 31 and a mouth 331 of the suction passages 33 and 33 A communicate while refrigerant is introduced into the cylinder bores 27 and 27 A (namely the double-headed piston 29 and 29 A moves from the left hand side of FIG. 1 toward the right). The refrigerant in the passage 212 of the rotary shaft 21 is introduced into the compression chamber 271 of the cylinder bores 27 and 27 A, by way of the introducing passage 31 and the suction passages 33 and 33 A. The fluid communication between the end 311 and the mouth 331 of suction passages 33 and 33 A are prohibited while the refrigerant in the cylinder bores 27 and 27 A is compressed (namely the double-headed piston 29 and 29 A move from the right hand side of FIG. 1 toward the left). The refrigerant compressed in the compression chamber 271 is discharged into the discharge chamber 131 from the discharge port 151 by pushing the discharge valve 161 . The refrigerant discharged into the discharge chamber 131 is expelled into an external refrigerant circuit not shown in the figures. An end 321 of an introducing passage 32 and a mouth 341 of the suction passage 34 and 34 A are kept in communication with each other while refrigerant is introduced into the cylinder bores 28 , 28 B and 28 A (namely the double-headed piston 29 and 29 A moves from the right hand side of FIG. 1 toward the left). The refrigerant in the passage 212 of the rotary shaft 21 is thus introduced into the compression chamber 281 of the cylinder bores 28 , 28 B and 28 A by way of the introducing passage 32 and the suction passages 34 and 34 A. The fluid communication between an end 321 and a mouth 341 of suction passage 34 and 34 A is prohibited while the refrigerant in the cylinder bores 28 , 28 B and 28 A is compressed (namely the double-headed piston 29 and 29 A moves from the left hand side of FIG. 1 toward the right). The refrigerant compressed in the compression chamber 281 is discharged into the discharge chamber 141 from the discharge port 181 by pushing the discharge valve 191 while the cylinder bores 28 , 28 A and 28 B are in discharging stroke. The refrigerant discharged into the discharge chamber 141 is expelled into an external refrigerant circuit. The refrigerant that is expelled to the external refrigerant circuit is circulated into the suction chamber 142 . Portions of the rotary shaft 21 which contact the sealing surfaces 113 and 123 act as the rotary valves 35 and 36 that are integrally formed with the rotary shaft 21 as shown in FIGS. 4 and 5 . Instead of contacting the rotary shaft 21 with the sealing surfaces, these can be positioned to minimize the gap between them in order to prevent leakage of the refrigerant. The rotary valves 35 and 36 contact the sealing surfaces 113 and 123 in their outer surfaces 351 and 361 . The sealing surface 113 is in an inner surface of valve accommodating portion 37 (shown in FIG. 4 ) which covers the rotary valve 35 . The sealing surface 123 is in an inner surface of valve accommodating portion 38 (shown in FIG. 5 ) which covers rotary valve 36 . When the cylinder bore 27 A shown in FIG. 1 is in discharging stroke, the lower cylinder bore 28 B shown in FIG. 3 is also in discharging stroke. A double-headed piston 29 A within the cylinder bore 27 A that is in discharging stroke receives reactive force while compressing the refrigerant in the cylinder bore 27 A and discharging the refrigerant to the discharge chamber 131 . This reactive force is transmitted to the rotary shaft 21 by way of the double-headed piston 29 A, the shoe 301 and the swash plate 23 . The reactive force transmitted to the swash plate 23 through the double-headed piston 29 A is applied to the swash plate 23 as a force shown by an arrow F 1 in FIG. 1 . The reactive force transmitted to the swash plate 23 through the double-headed piston 29 in the cylinder bore 28 B also is applied to the swash plate 23 as a similar force F 2 shown by an arrow F 2 in FIG. 1 . These forces F 1 and F 2 force the rotary shaft 21 , which integrally supports the swash plate 23 , to tilt centered at the center of the swash plate of 23 . The rotary shaft 21 is supported by a bearing so as to be releasable from the inner surface of through holes 112 and 122 . A displacement relative to the inner surface of the through holes 112 and 122 of the rotary shaft 21 is transmitted to the rotary valves 35 and 36 . In other words, the reactive force against compression is transmitted to the rotary shaft 21 through the double-headed pistons 29 A and 29 in the cylinder bores 27 A and 28 B in discharging stroke biases the rotary valve 35 in the direction of the cylinder bore 27 A that is in discharging stroke. Similarly, the rotary valve 36 is also biased by the reactive force in the direction of cylinder bore 28 B. The shoes 301 and 302 , the swash plate 23 and the rotary shaft 21 bias the rotary valves 35 and 36 by the reactive force toward the mouths 331 and 341 of the suction passage that communicate with the cylinder bores that are in discharging stroke. An outer surface 351 of the rotary valve 35 is biased toward the cylinder bore 27 A that is in discharging stroke. The outer surface 351 is urged toward the sealing surface 113 in proximity of the mouth 331 of the suction passage 33 A. The suction passage 33 A is in communication with the cylinder bore 27 A which is in discharging stroke. An outer surface 361 of the rotary valve 36 that is biased toward the cylinder bore 28 B of discharging stroke is pushed toward the sealing surface 123 in the proximity of the mouth 341 of the suction passage 34 . The suction passage 34 is in communication with the cylinder bore 28 B in discharging stroke. As a result, the refrigerant within compression chamber 271 and 281 of the cylinder bores 27 A and 28 B in discharging stroke is prevented from leaking from the suction passages 33 A and 34 . Accordingly, the volume efficiency in the compressor is improved. While the thrust bearing 25 is not provided with a function to absorb a thrust loading, the bearing 26 is provided with a function to absorb a thrust loading. The function of the bearing 26 to absorb the thrust loading modifies election tolerance due to dimensional error of the parts. Accordingly, the bearing 26 permits the swash plate 23 to rotate in the direction of F 1 and F 2 shown in FIG. 1 centered at the center of the swash plate 23 . In other words, the bearing 26 permits biasing the rotary valves 35 and 36 by reactive force in the direction of the mouth of the suction passage which communicates with the cylinder bore in discharging stroke. The configuration with the thrust bearing 26 acting to transmit the reactive force is a simple so that the refrigerant in the compression chambers 271 and 281 does not leak through the suction passage. A portion of the rotary shaft 21 that extends away from the swash plate 23 toward the rotary valve 35 is supported only by the radial bearing including the sealing surface 113 (that is an inner surface of the valve accommodating portion 37 ) and an outer surface 351 of the rotary valve 35 . The sealing surface 113 of the valve accommodating portion 37 acts as a radial bearing to support the rotary shaft 21 through the rotary valve 35 . The sealing surface 113 biases the rotary valve 35 by transmitting a reactive force toward the mouth 331 of the suction passage 33 A that communicate with the cylinder bore 27 A in discharging stroke. A portion of the rotary shaft 21 which extends away from the swash plate 23 toward the rotary valve 36 is supported only by the radial bearing including the sealing surface 123 (that is an inner surface of the valve accommodating portion 38 ) and an outer surface 351 of the rotary valve 35 . The sealing surface 123 of the valve accommodating portion 38 acts as a radial bearing to support the rotary shaft 21 through the rotary valve 36 . The sealing surface 123 biases the rotary valve 36 by transmitting the reactive force toward the mouth 341 of the suction passage 34 that communicate with the cylinder bore 28 B in discharging stroke. The configuration with the rotary shaft 21 supported by a radial bearing disposed in a portion of the outer surface of the rotary shaft 21 which extend away from the swash plate 23 toward the rotary valve improves an effect to block the mouth 331 and 341 of the suction passage 33 A and 34 A by a rotary valve 35 and 36 . The mouths 331 and 341 of the suction passages 33 A and 34 respectively communicating with the cylinder bores 27 A and 28 B in discharging stroke are closed by the urging force applied to the rotary valves 35 and 36 and reactive force. This closed state is not effected by a size of the gap between the outer surface 351 and 361 of the rotary valve 35 and 36 and the sealing surface 113 and 123 . Accordingly, because the strict control with respect to the tolerance of the gap is not required, the leakage of the refrigerant from the compression chamber 271 and 281 through the suction passages 33 A and 34 is prevented even in the cases where the precision of the gap is low. Namely, the volume efficiency of the compressor is improved even when the gap is not precisely in tolerance. The rotary shaft 21 is pressed against the sealing surface 113 of the cylinder block 11 in a position of rotary valve 35 . The shaft 21 is pressed against sealing surface 123 of cylinder block 12 in the position of rotary valve 36 . More concretely, the shaft 21 are pressed in an opposite directions. Therefore, it is necessary that the rotary shaft 21 be inclined to tilt with its center in the cross section, i.e. the center of the swash plate 23 . The surface of the rotary shaft 21 and the inner surface of the holes 112 and 122 contact in a small area in the longitudinal direction. This makes the rotary shaft 21 easy to tilt. The configuration with the sealing surfaces 113 and 123 having a radius smaller than that of the holes. 112 and 122 makes the rotary shaft 21 easy to tilt. The configuration with the rotary valve 35 and 36 fixingly supported on the rotary shaft 21 reduces the number of parts, resulting in the simple assembly process of the compressor. A second embodiment will described hereinafter by referring to FIGS. 6A through 8 . A front housing 40 and a rear housing 41 are connected to a cylinder block 39 as shown in FIG. 6A. A valve plate assembly is disposed between the cylinder block 39 and the rear housing 41 . A rotary shaft 46 is rotatably supported in the cylinder block 39 and the front housing 40 which defines a chamber 401 for which the pressure is controlled. The front housing 40 supports the rotary shaft 46 through a radial bearing 47 . The rotary shaft 46 extends through a through hole 391 formed within the cylinder block 39 , and the cylinder block 39 directly supports the rotary shaft 46 . A lag plate 48 is fixed to the rotary shaft 46 . A pair of guide holes 481 and 482 (shown in FIG. 7 ) are formed in the lag plate 48 . A swash plate 49 , which acts as a cam member, is supported on the rotary shaft 46 to be slidable and tiltable in the longitudinal direction. A hole 493 is formed in the swash plate 49 to pass through the rotary shaft 46 . A pair of guide pins 491 and 492 (shown in FIG. 7 ) are fixed to the swash plate 49 . The swash plate 49 is tiltable in the axial direction (with respect to an axis 461 ) and is integrally rotatable with the rotary shaft 46 by the association of the guide holes 481 and 482 and the guide pins 491 and 492 . While the swash plate 49 is illustrated by a solid line and a dotted line in FIG. 6A , the solid line shows the swash plate at its maximum tilt angle and the dotted line shows the swash plate at its minimum tilt angle. A plurality of single-headed pistons 51 and 51 A respectively are accommodated in a plurality of cylinder bores 50 and 50 A formed in the cylinder block 39 as shown in FIGS. 6A and 8 . A compression chamber 501 is defined within each of the cylinder bores 50 and 50 A. Rotational motion of the swash plate 49 is transmitted to the single-headed pistons 51 and 51 A through shoes 521 and 522 and converted into linear reciprocating motion of the single-headed pistons 51 and 51 A within the cylinder bores 50 and 50 A. A discharge chamber 411 and a suction chamber 412 are formed within the rear housing 41 as shown in FIG. 6A. A discharge port 421 and a discharge valve 431 are included in the valve plate assembly. The discharge valve 431 selectively opens the discharge port 421 . A retainer 441 is formed to regulate the opening size of the discharge valve 431 . A thrust bearing 53 is disposed in between the lag plate 48 and the front housing 40 . A shaft seal 45 is interposed between the front housing 40 and the rotary shaft 46 . A passage 462 is formed through the rotary shaft 46 . An end of the passage 462 is in the inside edge of the rotary shaft 46 to open into the suction chamber 412 within the rear housing 41 . A discharge chamber 411 and a chamber 401 are in communication through a refrigerant passage 54 . A displacement control valve 55 is disposed on the refrigerant passage 54 . The displacement control valve 55 controls the amount of the refrigerant which flows out from the discharge chamber 411 into the chamber 401 , pressure of which is controlled. The chamber 401 and the suction chamber 412 are in communication through the passage 462 and the refrigerant passage 56 . The refrigerant in the chamber 401 flows out to the suction chamber 412 through the refrigerant passage 56 . The tilt angle of the swash plate 49 is decreased as the pressure in the chamber 401 increase, and the tilt angle increases as the pressure in the chamber 401 is reduced. The displacement control valve 55 controls the tilt angle of the swash plate by adjusting the pressure within the chamber 401 . The radius of the through hole 391 allowing the rotary shaft 46 to extend therethrough varies in the longitudinal direction and a portion of the inner surface of the hole acts as a sealing surface 392 . The radius at the sealing surface 392 is smaller than that at other portions of the inner surface of the through hole 391 . The rotary shaft 46 is directly supported by the cylinder block 39 through the sealing surface 392 . A plurality of suction passages 58 and 58 A are formed in the cylinder block 39 to allow the cylinder bores 50 and 50 A to communicate with the through hole 391 as shown in FIG. 8 . Mouths 581 of the suction passages 58 and 58 A open in the sealing surface 392 . An introducing passage 57 is formed in the rotary shaft 46 to be in communication with the passage 462 . An end 571 of the introducing passage 57 intermittently communicate with the mouths 581 of the suction passages 58 , and 58 A in accordance with the rotation of the rotary shaft 46 . An end 571 and the mouths 581 of the suction passages 58 and 58 A communicate while the refrigerant is introduced into the cylinder bores 50 and 50 A (namely the single-headed pistons 51 and 51 A move from the right hand side of FIG. 6A toward the left). The refrigerant in the passage 462 of the rotary shaft 46 is introduced into the compression chamber 501 of the cylinder bores 50 and 50 A through the introducing passage 57 and the suction passages 58 and 58 A while the cylinder bores 50 and 50 A are in suction stroke. The fluid communication of the end 571 and the mouths 581 of the suction passages 58 and 58 A are prohibited while the refrigerant in the cylinder bores 50 and 50 A is compressed (namely the single-headed pistons 51 and 51 A move from the left hand side of FIG. 6A toward the right). The refrigerant is compressed in the compression chamber 501 in a compression stroke, and is discharged into a discharge chamber 411 from a discharge port 421 by pushing the discharge valve 431 . The refrigerant discharged into the discharge chamber 411 is expelled out into an external refrigerant circuit not shown in the figures. The refrigerant expelled into the external refrigerant circuit is circulated into the suction chamber 412 . A portion of the rotary shaft 46 which contacts the sealing surface 392 acts as a rotary valve 59 integrally formed with the rotary shaft 46 as shown in FIG. 6 B. Instead of contacting the rotary shaft with the sealing surfaces, these can be positioned to minimize the gap between them in order to prevent leakage. A sealing surface 392 , to which the outer surface 591 of the rotary valve 59 contacts, is an inner surface of the valve accommodating portion 60 in which the rotary valve 59 is contained. A single-headed piston 51 A within the cylinder bore 50 A receives a reactive force from the refrigerant while compressing and discharging the refrigerant of the cylinder bore 50 A into the discharge chamber 411 , during discharging stroke of the cylinder bore 50 A shown in FIG. 6A. A portion of the reactive force is transmitted to the front housing 40 by way of a single-headed piston 51 A, a shoe 521 , a swash plate 49 , guide pins 491 and 492 , a lag plate 48 and a thrust bearing 53 . The reactive force transmitted to the swash plate 49 through a single-headed piston 51 A is applied to the swash plate 49 as a force shown by an arrow F 3 in FIG. 6 A. The force F 3 biases the swash plate 49 toward upper direction of FIG. 6 A. The guide holes 481 and 482 are in the form of a hole directing substantially radial direction of the rotary shaft 46 . Accordingly, the engagement of the guide pins 491 and 492 to the guide holes 481 and 482 will not disturb a motion of the swash plate 49 toward upper direction shown in FIG. 6 A. The motion of the swash plate 49 toward the upper direction of FIG. 6A biases the rotary shaft 46 in the upper direction of FIG. 6 A through engagement of the hole 493 and the surface of rotary shaft 46 . The biasing force acts as a moment loading having a center in the position of engagement between the rotary shaft 46 and the radial bearing 47 , so that the rotary valve 59 is biased in the direction of the cylinder bore 50 A in discharging stroke. Namely, a reactive force transmitted to the rotary shaft 46 through a single-headed piston 51 A in the cylinder bore 50 A in discharging stroke biases the rotary valve 59 in the direction of the cylinder bore 50 A. A shoe 521 , a swash plate 49 , a hole 493 and a rotary shaft 46 bias the rotary valve 59 by the reactive force in the direction of the mouth 581 of the suction passage which is in communication with a cylinder bore that is in discharging stroke. An outer surface 591 of the rotary valve 59 which is biased in the direction of a cylinder bore 50 A in a discharging stroke is pushed against the sealing surface 392 so as to block the mouth 581 of the suction passage 58 A. As a result, the refrigerant within the compression chamber 501 in the cylinder bore 50 A in discharging stroke is prevented from leaking so as to improve the volume efficiency in the compressor. A portion of the rotary shaft 46 which extends from the swash plate 49 toward the rotary valve 59 is supported only by a radial bearing including a sealing surface 392 (that is inner surface of a valve accommodating portion 60 ) and the outer surface 591 of the rotary valve 59 . The sealing surface 392 , which is the inner surface of the valve accommodating portion 60 , acts as a part of radial bearing which supports the rotary shaft 46 through rotary valve 59 . Further, the sealing surface 392 transmits the reactive force from the compressed refrigerant. The structure in which the rotary shaft 46 is supported solely by a radial bearing at a portion of the rotary shaft 46 which extends away from the swash plate 49 toward the rotary valve 59 improves the effect of blocking the mouth of the suction passage by a rotary valve. A mouth 581 of the suction passage 58 A which communicates with a cylinder bore 50 A in discharging stroke is closed by pushing the rotary valve 59 by the reactive force. This closed state is not effected by the clearance size between the outer surface 591 of the rotary valve and the sealing surface 392 . Accordingly, strict control is not necessary with respect to the tolerance of this clearance and the refrigerant which pass through from a compression chamber 501 within a cylinder bore 50 A in discharging stroke to the suction passage 58 A is prevented from leaking even in the cases where the manufacturing precision of the clearance is low. Namely, the volume efficiency in a compressor is improved in the cases where the manufacturing precision of the clearance is low. In order that the rotary shaft 46 is pushed against a sealing surface 392 of the cylinder block 39 in a position of a rotary valve 59 , the rotary shaft 46 is required to be easily tilted in the direction toward the cylinder bore 50 A which is in discharging stroke. The rotary shaft 46 is more easily tilted as an area where an outer surface of the rotary shaft 46 and an inner surface of a hole 391 contact is smaller in the longitudinal direction of the rotary shaft 46 . The structure which provides a sealing surface 392 having a smaller radius compared to other portions within the through hole 391 makes the rotary shaft 46 easier to tilt. The structure in which a rotary valve 59 is integrally formed with a rotary shaft 46 reduces the number of parts and simplifies assembly process of the compressor. The third embodiment shown in FIGS. 9 through 11 are next described. Elements similar to those described in the first embodiment are numbered with like reference numerals. Rotary valves 62 and 63 are fixed to a rotary shaft 61 and are contained within valve accommodating portions 64 and 65 . Introducing passages 66 and 67 formed in rotary valves 62 and 63 are in communication with a swash plate chamber 24 . The swash plate chamber 24 is a suction chamber which communicates with an external refrigerant circuit (not shown in the figures). Ends 661 and 671 of the introducing passages 66 and 67 and mouths 331 and 341 of suction passages 33 , 33 A, 34 and 34 A intermittently communicate along with rotation of rotary valves 62 and 63 . Refrigerant within the swash plate chamber 24 is introduced into the compression chambers 271 and 281 of the cylinder bores 27 and 28 that are in suction stroke, by way of the introducing passages 66 and 67 and suction passages 33 , 33 A, 34 and 34 A. The displacement of a rotary shaft 61 in the direction of the axis 611 is regulated by a pair of thrust bearings 68 and 69 . Both of the thrust bearings 68 and 69 are provided with a function to absorb thrust loading. The thrust bearings 68 and 69 act to transmit a reactive force against compression similarly as a thrust bearing 26 described with respect to the first embodiment. While the number of parts is increased in the third embodiment since the rotary valves 62 and 63 are provided separately from the rotary shaft 61 , other advantages as described with respect to the first embodiment can be obtained similarly. It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms. The thrust bearing 25 of the first embodiment may be provided with a function to absorb thrust loading. By providing such function, the rotary valves 35 and 36 are more easily allowed to be pushed toward the mouth of the suction passage which communicate cylinder bores that are in discharging stroke, by the compression reactive force. As a result, the refrigerant in the compression chambers in the cylinder bores that are in discharging stroke are prevented from leaking, and the volume efficiency of the compressor is improved. In the case where the rotary valve is integrally formed with rotary shaft, the rotary shaft may be manufactured to have a maximum radius in the proximity at a position where the rotary valve is formed. In this way, a portion of the rotary shaft which extends from the swash plate toward the rotary valve is supported only by a radial bearing including a sealing surface (that is inner surface of valve accommodating portion) and an outer surface of the rotary valve so as to improve effect to block the mouth of the suction passage by the rotary valve. The pistons may have a hollow structure. Examples of such are shown in FIGS. 12A and 12B . Namely, a double-headed piston 29 A of FIG. 12A comprises a body portion 701 that is connected to shoes 301 and 302 , and cap portions 702 that are fixed at reciprocating ends of the body portion 701 . The double-headed piston 29 A has a hollow structure with a space 703 , which is enclosed by the body portion 701 and the cap portion 702 . Other double-headed pistons 29 have similar structures. A single-headed piston 51 A of FIG. 12B comprises a coupling portion 711 to be coupled with shoes 521 and 522 , and a head portion 712 that is fixed at a rear end of the coupling portion 711 . The single-headed piston 51 A has a hollow structure with a space 713 , which is enclosed by the coupling portion 711 and the head portion 712 . In this case, other single-head pistons 51 have similar structures. A piston receives an inertial force which is directed to a direction opposite to the compression reactive force. Accordingly, the forces F 1 , F 2 and F 3 , which work on the swash plate 23 due to the compression reactive force, are smaller as the inertial force increases. The biasing force, which pushes the outer surface of the rotary valve toward the sealing surface in the neighborhood of the suction passage when the piston receives the compression reactive force from the refrigerant, is weakened. Accordingly, the inertial force is lowered in the case where the weight of the pistons is reduced by adopting a hollow structure, compared to a case where the pistons are solid. In this way, decrease in the volume efficiency due to leakage of refrigerant within the compression chambers that are in discharging stroke through the suction passages, is suppressed. The swash plate 23 can be made of a material such as iron (including iron alloy) having a larger specific gravity than aluminum, in the first and the third embodiments. In this way, the centrifugal force, which acts on the swash plate 23 during rotation of the rotary shaft 12 , can be increased without manufacturing larger swash plate, compared to the case where the swash plate 23 is made of aluminum. The rotary shaft 21 receives a force which acts to rotate the fixed rotary shaft 21 and the swash plate 23 in a direction in which an angle between the longitudinal direction of the plate-shaped portion 235 and the central axis of the housing increases toward 90 degrees. This direction is clockwise in FIGS. 1 and 9 . In other words, such force acts upon the rotary valve 35 and 36 to be forced toward the mouth 331 and 341 of the suction passage in communication with the cylinder bore which is in discharging stroke. Since the swash plate 23 of the first and the third embodiments comprises aluminum, the swash plate has a relatively light weight. The above described effect of the centrifugal force to push the rotary valve 35 and 36 toward mouth 331 and 341 of suction passage is not fully exhibited in these embodiments. On the other hand, the force to push the rotary valve 35 and 36 toward mouth 331 and 341 of suction passage communicating the cylinder bore in the discharging stroke is increased when the swash plate 23 is formed from a material which has a relatively large specific gravity such as materials comprising iron. The refrigerant in the compression chambers that are in discharging stroke is prevented from leaking through suction chamber in this way, so that the volume efficiency of the compressor is increased. While the rotary valve of the first and second embodiments are described to be pushed against the inner surface of the valve accommodating portion, the rotary valves can be formed to decrease clearance in between to prevent leakage, instead of contacting the inner surface of the valve accommodating portion. It is also possible to apply present invention to a wobble type variable displacement compressor disclosed in Japanese Laid-Open Patent Publication 5-113174, constant displacement piston type compressor having a single-headed piston and a piston type compressor having a cam member having a shape other than swash plate, a wave cam for example. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.

A refrigeration suction mechanism used in a piston type compressor. The compressor comprises a rotary shaft, a plurality of pistons, a compression chamber and a rotary valve. The pistons are arranged in a circumference of the rotary shaft to reciprocate in conjunction with a rotating motion of the rotary shaft through a cam member. An end surface of one of said pistons reciprocates in the compression chamber. The rotary valve includes an introducing passage which allows refrigerant to flow into the compression mechanism through an end opened on an outer surface of the rotary valve. The refrigeration suction mechanism comprises a suction passage and a reactive force transmitting mechanism. The suction passage communicates with the cylinder bore and intermittently communicates with the end of the introducing passage in conjunction with a rotating motion of the rotary valve. The reactive force transmitting mechanism transmits a reactive force applied on one of the pistons that is in a discharging stroke so as to press the rotary valve against a mouth of the suction passage which communicates with a cylinder bore that contains the piston in the discharging stroke.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a divisional application of and claims priority to pending U.S. application Ser. No. 11/812,300 filed on Jun. 18, 2007, and entitled RADIO FREQUENCY SHIELDING APPARATUS SYSTEM AND METHOD, the entire contents of which is expressly incorporated by reference herein. BACKGROUND [0002] The present disclosure generally relates to radio frequency shielding for a commercial aircraft. More particularly, the disclosure pertains to a method and system that assists in attenuating electromagnetic propagation through commercial aircraft passenger windows, aircraft doors or the like. BACKGROUND [0003] Generally, the fuselage of commercial aircraft are extremely efficient at attenuating electromagnetic radiation or energy such as radio frequency (RF) energy. Conventional aircraft typically include an outer skin of aluminum or include a conductive mesh or coating to dissipate lightning strikes. This conductive skin reflects and attenuates RF energy to a high degree. However, commercial aircraft generally also include a number of electromagnetic apertures. Aircraft windows and doors are two of the most common electromagnetic apertures inherent to most commercial aircraft designs. During operation of commercial aircraft, these apertures allow RF energy to enter and exit the aircraft. [0004] This property of aircraft windows and doors is undesirable for several reasons. For example, externally generated RF transmissions may interfere with on-board systems. In another example, internally generated RF transmissions may interfere with on-board systems and/or may violate the rules of the United States Federal Communications Commission (FCC) and other such regulatory institutions. [0005] Accordingly, it is desirable to provide a cost effective method and apparatus for attenuating electromagnetic propagation through aircraft passenger windows or the like at least to some extent. SUMMARY [0006] The foregoing needs are met, at least to some extent, by the present disclosure, wherein in one respect a system, assembly, and method is provided that in some embodiments attenuates electromagnetic propagation through an aperture in an aircraft. [0007] An embodiment relates to a system for shielding an aircraft from electromagnetic energy. The system includes a fuselage, aperture, window mounting, and window plug. The fuselage provides an electrically conductive envelope. The aperture is disposed in the fuselage. The window mounting spans the aperture. The window plug spans the aperture. The window mounting and the window plug are electrically coupled to the fuselage and provide an electrical path spanning the aperture. [0008] Another embodiment pertains to an assembly for shielding an aperture in a fuselage of an aircraft from electromagnetic energy. The assembly includes a window mounting and a window plug. The window mounting spans the aperture. The window plug spans the aperture. The window mounting and the window plug are electrically coupled to the fuselage and provide an electrical path spanning the aperture. [0009] Yet another embodiment relates to a method of shielding an aperture in a fuselage of an aircraft from electromagnetic energy. In this method, a window mounting is conductively connected to the fuselage and a window plug is conductively connected to the window mounting. [0010] There has thus been outlined, rather broadly, certain embodiments that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments that will be described below and which will form the subject matter of the claims appended hereto. [0011] In this respect, before explaining at least one embodiment in detail, it is to be understood that embodiments are not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. In addition to the embodiments described, the various embodiments are capable of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. [0012] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the disclosure. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the various embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is an exploded view of a system for shielding an aperture according to an embodiment. [0014] FIG. 2 is a cross-sectional perspective view of a window mounting suitable for use with the system according to FIG. 1 . [0015] FIG. 3 is a cross-sectional view of a capacitive gasket suitable for use with the window mounting according to FIG. 2 . [0016] FIG. 4 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of coated windows suitable for use with the system according to FIG. 1 . [0017] FIG. 5 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of coated windows and electronically dimmable windows suitable for use with the system according to FIG. 1 . [0018] FIG. 6 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of coated windows and grounded electronically dimmable windows suitable for use with the system according to FIG. 1 . [0019] FIG. 7 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of coated windows and circumferentially bonded electronically dimmable windows suitable for use with the system according to FIG. 1 . [0020] FIG. 8 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of a coated bellows suitable for use with the system according to FIG. 1 . DETAILED DESCRIPTION [0021] Various embodiments will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present disclosure provides a method and system that assists in attenuating electromagnetic propagation, for example RF energy, through commercial aircraft apertures such as passenger windows, aircraft doors or the like. More particularly, an embodiment provides an aircraft aperture assembly or system having a plurality of components that, when assembled in an aircraft frame or fuselage, assists in the attenuation of the transmission of RF energy therethrough. [0022] Referring now to FIG. 1 , a window system 10 includes a window mounting 14 and window plug 16 . The window mounting 14 is configured to be mounted in or mated with a window opening 18 in an outer skin 20 of an aircraft (not shown). The window plug 16 is configured to be mounted in or mated with a plug opening 22 in an inner skin 24 of the aircraft. The window mounting 14 includes a capacitive gasket 28 , outer window 30 , inner window 32 , and window forging 34 . The window mounting 14 is further described in FIGS. 2 and 3 . The window plug 16 includes a bellows seal 40 , outer reveal 42 , electronically dimmable window (EDW) 44 , inner reveal 46 , dust cover 48 , and window plug molding 50 . [0023] In general, some or all of the various components of the window system 10 are configured to conduct electricity sufficiently well enough to reflect and/or attenuate electromagnetic energy such as RF energy. More particularly, when installed in an electrically conductive envelope such as a fuselage of an aircraft, the assembled components of the window system 10 provide a conductive path spanning the window opening 18 in the outer skin 20 of the fuselage. In this manner, electromagnetic energy such as RF energy generated within the fuselage may be attenuated or essentially prevented, to a large extent, from entering or exiting the fuselage. It is an advantage of various embodiments that RF energy may be attenuated to such an extent that signals emanating from within the fuselage can not reasonably be detected outside the fuselage. It is another advantage of various embodiments that, for the purposes of the United States Federal Communications Commission (FCC) and other such regulatory institutions, the interior of an aircraft outfitted with the window system 10 may be classified an indoor environment due to the attenuation of RF energy provided by the window system 10 . [0024] In FIG. 2 , a particular embodiment of the commercial aircraft window mounting, generally designated 14 , is illustrated. The commercial aircraft window mounting 14 includes the capacitive gasket 28 positioned between and/or partially surrounding the outer window 30 and the inner window 32 . The commercial aircraft mounting 14 additionally includes the window forging 34 that is configured to mate with the airframe or outer skin 20 of the aircraft. The window forging 34 includes a radial flange 56 and an axial flange 58 . The window forging 18 also includes a base portion 60 that extends in opposing relationship to the radial flange 56 . That is, the base portion 60 extends generally inwardly or opposite the radial flange 56 as previously discussed, and provides an inwardly and downwardly sloping surface 62 . [0025] As illustrated in FIG. 2 , the commercial aircraft window mounting 14 further includes a series of spring clips 64 positioned about the periphery of the window forging 34 . The commercial aircraft window mounting 14 also has a series of mounting flanges 66 and a series of bolts 68 , or other such mechanical attachments or fasteners, also positioned about the periphery of the forging 34 . The mounting flanges 66 are connected to, and extend from, the axial flange 58 of the window forging 34 . The mounting flanges 66 are positioned about the periphery of the window forging 34 as illustrated in FIG. 1 , and combine with the spring clips 64 and the bolts 34 to mount the gasket 28 and outer and inner windows 30 , 32 to the window forging 34 . [0026] Referring now to FIGS. 2 and 3 , a cross-sectional view of the gasket 28 is illustrated. As depicted in FIGS. 2 and 3 , the gasket 28 encircles the outer window 30 and inner window 32 and provides a circumferential bond between the outer and inner windows 30 , 32 and the window forging 34 . The gasket 28 is a capacitive gasket that provides a capacitive bond between the windows 30 , 32 and the window forging 34 . The gasket 28 includes a lower portion or section 70 , a mid-section or portion 72 and an upper portion or section 74 . [0027] As illustrated in FIGS. 2 and 3 , the lower section 70 of the gasket 28 extends from the mid-section 72 of the gasket 28 at an angle in a downwardly direction, away for the window forging 34 . The aforementioned geometry of the lower section 70 of the gasket 28 generally mirrors or compliments the downwardly sloping surface 62 of the base portion 60 . The lower section 70 includes a series of ridges, generally designated 78 , that extend outwardly from the lower section 70 . As depicted in FIGS. 2 and 3 , the mid-section 72 , as the name suggests, occupies the middle portion of the gasket 28 and functions as a spacer between the outer window 30 and inner window 32 . The upper portion 74 extends upwardly from the mid-section 72 , generally parallel to the axial flange 58 of the window forging 34 . [0028] In various embodiments, the gasket 28 includes a conductive media that is bound by an elastomeric matrix. The conductive media includes any suitable strongly, weakly, and/or semi-conductive materials. Specific examples of conductive materials include conductive carbon black, aluminum, silver, and the like. The elastomeric matrix includes ethylene propylene diene monomer (EPDM) and the like. In one embodiment, the capacitive gasket 28 includes a carbon black media in an EPDM or other such elastomeric matrix. Alternatively, the gasket 28 may include silver and/or aluminum flakes in an EPDM or other such elastomeric matrix. The carbon black media provides greater than 20 dB to about 45 dB of RF energy shielding in the range of from about 80 MHz to approximately 18 GHz of the electromagnetic spectrum. The silver and/or aluminum flake media provides approximately 10 dB to about 47 dB of RF energy shielding in the range of from about 80 MHz to approximately 18 GHz of the electromagnetic spectrum. [0029] As previously discussed, during operation of commercial aircraft for example, the aircraft encounters electromagnetic energy in the form of RF radiation from external sources. This RF radiation can interfere with the operation of the commercial aircraft systems such as the communication system and the navigation system. Accordingly, in order to attenuate the propagation of RF radiation through the commercial aircraft passenger windows, techniques such as shielding are implemented to reduce electromagnetic propagation. During the shielding process and, prior to assembly of the window system 10 the windows are treated with a film or material that reflects electromagnetic energy. As illustrated in FIG. 1 , the inner window 32 has been shielded or treated, as generally designated by reference numeral 76 , with a film or other material that reduces or attenuates the propagation of electromagnetic radiation. The shielding 76 includes any suitable film, layer, and/or treatment operable to reflect, attenuate, or otherwise reduce the propagation of electromagnetic energy. Suitable examples of the shielding 76 include conductive films, meshes, and the like. [0030] The shielded inner window 32 combines with the gasket 28 to reduce electromagnetic propagation through the passenger windows of a commercial aircraft. As previously discussed, the shielded window 32 reflects electromagnetic radiation, however as the frequency of electromagnetic energy increases, for example, to approximately 1 GHz to approximately 2 GHz, the window may begin to lose its attenuation characteristics and begin to resonate and retransmit the electromagnetic energy. To avoid such instances, the gasket 28 provides a capacitive coupling between the inner window 32 and the commercial aircraft frame, dissipating the electromagnetic energy onto the aircraft frame or outer skin 20 . In this regard, the gasket 28 includes a material having a dielectric constant, permittivity, and/or resistance such that the gasket 28 is configured to discharge electromagnetic energy from the window 32 to the window forging 34 prior to resonance of the window 32 . That is, the window 32 is configured to reflect electromagnetic energy until the energy exceeds a predetermined maximum amount of energy. If the window 32 were to remain electrically isolated past this predetermined maximum amount of energy, the window 32 may transmit RF energy. The gasket 28 is configured to conduct electromagnetic energy or electricity from the window 32 to the window forging 34 prior to the amount of energy in the window 32 exceeding the predetermined maximum. The gasket 28 further assists the attenuation electromagnetic radiation by absorbing some of the electromagnetic energy as heat. [0031] FIGS. 4-7 are examples of graphs showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of components suitable for use with the system according to FIG. 1 . As shown in FIG. 4 , the window 30 and/or 32 , when coated with a thin, essentially transparent, coating of gold, attenuates approximately 20 decibels (dB) of electromagnetic (EM) energy within a frequency range of about 300 megahertz (MHz) to about 11,000 MHz. As shown in FIG. 5 , when the coated window 30 and/or 32 is combined with the EDW 44 , approximately 25 dB of EM energy is attenuated within a frequency range of about 300 MHz to about 11,000 MHz. That is, assembling these two components increases the attenuation. Similarly, as shown in FIG. 6 , by grounding the EDW 44 , approximately 35 dB of EM energy is attenuated within a frequency range of about 300 MHz to about 11,000 MHz. The attenuation is further again increased by circumferentially bonding the EDW 44 within the window system 10 . In a particular embodiment, the EDW 44 is circumferentially bonded to the window system 10 via the bellows seal 40 . For example the bellows seal 40 is conductively coated or otherwise configured to conduct EM energy. In a particular example, the bellows seal 40 is coated with an electrically conductive silicone-based ink. This ink may include any suitable conductive material such as, for example, aluminum, silver, gold, carbon, and the like. While in general, any suitable coating material that exhibits good adhesion to the bellows seal 40 , flexibility, and conductivity may be utilized in various embodiments, specific examples of coating materials may be manufactured by Creative Materials, Inc. of Tyngsboro, Mass. 01879, U.S.A. In particular, product number 115-08, electrically conductive silicone ink with 87% silver (cured) is suitable for use with various embodiments. It is to be understood that the graphs illustrated in FIGS. 4-7 are for illustrative purposes only, and thus, the respective curvatures, slopes and y-intercepts may be the same or different depending on the response of the various EM energy attenuators. [0032] FIG. 8 is an example of a graph showing frequency in MHz (abscissa) as it affects the shielding effectiveness in dB (ordinate) of a coated bellows suitable for use with the system according to FIG. 1 . As shown in FIG. 8 , when coated with electrically conductive silicone ink with 87% silver (cured), the bellows seal 40 attenuates approximately 20 dB. It is to be understood that the graph illustrated in FIG. 8 is for illustrative purposes only, and thus, the respective curvatures, slopes and y-intercepts may be the same or different depending on the response of the various EM energy attenuators. [0033] The many features and advantages of the various embodiments are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages that fall within the true spirit and scope of the embodiments. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the embodiments to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the various embodiments.

An assembly for shielding an aircraft from electromagnetic energy may include a window mounting configured to be conductively coupled to an aperture in a fuselage of an aircraft. The window mounting may include a window pane having an electromagnetically-reflective coating for reflecting electromagnetic energy. The window pane may remain electrically isolated from the fuselage prior to the electromagnetic energy exceeding a frequency of approximately 1 GHz. The window mounting may further include a capacitive gasket capcaitively coupling the window pane to the fuselage after the frequency of the electromagnetic energy reflected by the window pane exceeds approximately 1 GHz.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable REFERENCE TO A MICROFICHE APPENDIX [0003] Not Applicable BACKGROUND OF THE INVENTION [0004] The present invention relates to a novel dolly dropdown box drawer mounted on a tow truck for the storage and securing of a towing dolly within the drawer. Preferably, a pair of drawers are attached to an underside of a bed or frame of the tow truck. Preferably, each dolly dropdown box drawer includes a lockable latching mechanism that is keyed to permit the locking of the drawer to secure the towing dolly stored within. BRIEF SUMMARY OF THE INVENTION [0005] An objective of this invention, a dolly dropdown box drawer, is to provide a novel and improved storage apparatus on a tow truck and to facilitate the usage of a pair of towing dollies by storing them lower on the tow truck than is customary in the art. A further object of the invention is to enclose each towing dolly within a dolly dropdown box drawer and thereby protect each towing dolly when not in use from pilferage, weather, road hazards, road debris, and other undesired influences. [0006] Another objective of the invention is to utilize space below a bed or frame of a tow truck that is currently underutilized. Another further object is to present a towing dolly in an open dolly dropdown box drawer advantageously in an orientation ready for use by a tow truck driver. Ergonometric advantages for a tow truck driver are promoted because with the instant dolly dropdown box drawer invention, the driver retrieves a towing dolly from a drawer below waist level rather than at or above waist level. The dolly dropdown box drawer presents a towing dolly in an appropriate orientation for ready use by the driver with a vehicle to be recovered or towed. [0007] The invention helps a tow truck driver safeguard his back and body from injury that in the absence of the invention might be caused by lifting a heavy towing dolly from an inconvenient location on a tow truck. [0008] The dolly dropdown box drawer is preferably made from steel and aluminum plate, angle iron, and rod stock together with appropriate mechanical fittings such as bolts, nuts, washers, bearings, bushings, locks, and rods. Other suitable materials could be substituted in place of steel and aluminum plate, angle iron, and rod stock without departing from the intended scope of the invention. [0009] Additional and various other objects and advantages attained by the invention will become more apparent as the specification is read and the accompanying figures are reviewed. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0010] FIG. 1 is a perspective view of a pair of dolly dropdown box drawers disposed under a bed structure of a tow truck; [0011] FIG. 2 is a perspective view of a dolly dropdown box drawer in an open position with a towing dolly resting within a dolly dropdown box drawer assembly within a dolly dropdown box drawer support frame; [0012] FIG. 3 is an exploded view of a dolly dropdown box drawer; [0013] FIG. 4 is a partial perspective fragmentary view of a dolly dropdown box drawer in a closed position with a dolly dropdown box drawer assembly nesting within a dolly dropdown box drawer support frame; [0014] FIG. 5 is a perspective view of a dolly dropdown box drawer in a partially open condition with a dolly dropdown box drawer assembly translated laterally and outwardly from a closed position within a dolly dropdown box drawer support frame; [0015] FIG. 6 is a partial perspective fragmentary view of a drawer pull handle and a latching mechanism of a dolly dropdown box drawer assembly; [0016] FIG. 7 is a partial perspective view of a dolly dropdown box drawer assembly in an open position within a dolly dropdown box drawer support frame; [0017] FIG. 8 is an interior view of a dolly dropdown box drawer assembly from above when a dolly dropdown box drawer assembly is in an open position and showing a latching mechanism and two shaped sliding rods; [0018] FIG. 9 is an interior, partial perspective view of a right end of a dolly dropdown box drawer with a dolly dropdown box drawer assembly in an open position; [0019] FIG. 10 is a partial perspective view of a support end side wall of a dolly dropdown box drawer support frame with a dolly dropdown box drawer assembly within in an open position with a right front track follower assembly resting in a right front track detent depression and a right rear track follower assembly at the top front of a front portion of a right rear track; [0020] FIG. 11 is an interior, partial perspective view of a right end of a dolly dropdown box drawer with a dolly dropdown box drawer assembly tilting forward within a dolly dropdown box drawer support frame showing a right rear track follower assembly fully translated upwardly along a front portion of a right rear track; [0021] FIG. 12 is a right end side elevation of a dolly dropdown box drawer support frame with a dolly dropdown box drawer assembly within in a closed position; [0022] FIG. 13 is a right end side elevation of a dolly dropdown box drawer support frame with a dolly dropdown box drawer assembly within translated laterally and outwardly to an intermediate position from a closed position and towards an open position; [0023] FIG. 14 is a right end side elevation of the dolly dropdown box drawer support frame with a dolly dropdown box drawer assembly within translated laterally and outwardly to a lateral detent depression position from a closed position; [0024] FIG. 15 is a partial right end side elevation of a dolly dropdown box drawer frame with a dolly dropdown box drawer assembly within translated laterally and outwardly to a lateral detent depression position from a closed position and with the dolly dropdown box drawer assembly rotating about the axis of a right front track follower assembly resting in a right front track detent depression and a right rear track follower assembly located within a front portion of a right rear track; [0025] FIG. 16 is a right end side elevation of a dolly dropdown box drawer in an open position showing a dolly dropdown box drawer support frame with a dolly dropdown box drawer assembly within translated laterally and outwardly to a lateral detent depression position from a closed position and with the dolly dropdown box drawer assembly rotating about the axis of a right front track follower assembly resting in a right front track detent depression and a right rear track follower assembly arced fully upwardly and forwardly along a front portion of a right rear track; and [0026] FIG. 17 is front elevation of a dolly dropdown box drawer in a closed position. DETAILED DESCRIPTION OF THE INVENTION [0027] Referring to FIGS. 1 through 17 , a tow truck 8 often is equipped with a pair of towing dollies 10 and the tow truck typically includes a bed structure 12 having an underside 14 located behind a driver's cab 16 , the present invention is a novel dolly dropdown box drawer 20 that is fastened preferably with nuts and bolts to the underside of the bed structure in proximity to the driver's cab, along the driver's side of the truck, and extending towards the rear of the truck. Preferably a second dolly dropdown box drawer 20 is fastened to the underside 14 of the bed structure 12 in proximity to the driver's cab 16 , along the passenger's side of the truck, and extending towards the rear of the truck to comprise a pair of drawers to receive, hold, and store a pair of towing dollies. [0028] The dolly dropdown box drawer 20 comprises a dolly dropdown box drawer assembly 22 supported within a dolly dropdown box drawer support frame 24 . [0029] The dolly dropdown box drawer assembly 22 comprises a multiwalled drawer having spaced and opposed drawer side walls 26 and 28 , a drawer back wall 30 spaced from and partially opposed by a drawer front wall 32 , a drawer bottom wall 34 spaced from and partially opposed by a drawer top wall 36 depending from the drawer back wall. [0030] The dolly dropdown box drawer support frame 24 preferably is made from one piece of rectangular steel plate that is formed with a brake into a pair of spaced and opposed support end side walls 38 and 40 connected by an intermediate top wall portion 42 and with the end side walls depending downward from the intermediate top wall portion. [0031] The dolly dropdown box drawer assembly 22 preferably includes a pair of spaced and opposed front track follower assemblies 44 and 46 that project from the drawer side walls 26 and 28 and are received within and cooperate with a pair of spaced and opposed front tracks 48 and 50 on the support end side walls 38 and 40 , respectively, with each front track located towards a lower edge and a front edge of a respective support end side wall. [0032] The dolly dropdown box drawer assembly 22 preferably includes a pair of spaced and opposed rear track follower assemblies 52 and 54 that project from the drawer side walls 26 and 28 and are received within and cooperate with a pair of spaced and opposed rear tracks 56 and 58 on the support end side walls 38 and 40 , respectively, with each rear track located towards a lower edge and a back edge of a respective support end side wall. [0033] The front track follower assemblies 44 and 46 are preferably located approximately at a midportion of the dolly dropdown box drawer assembly 22 in proximity to the drawer back wall 30 . The front track follower assemblies 44 and 46 preferably are loosely received within the front tracks 48 and 50 , respectively, permitting the dolly dropdown box drawer assembly 22 to move relative to the dolly dropdown box drawer support frame 24 . The front tracks 48 and 50 are preferably rectangular in shape, thus permitting front track follower assemblies 44 and 46 to move (within front tracks 48 and 50 , respectively) forward from a closed position (see FIGS. 1, 4 , 12 , and 17 ) to an open position (see FIGS. 2, 7 , 9 , 10 , and 16 ). Preferably, the front tracks 48 and 50 each has a front track detent depression 60 and 62 with each front track detent depression located towards a front edge of a respective support end side wall. [0034] The rear track follower assemblies 52 and 54 are preferably located at an end portion of the dolly dropdown box drawer assembly 22 in proximity to the drawer back wall 30 and away from the midportion of the dolly dropdown box drawer assembly and the drawer bottom wall 34 . The rear track follower assemblies 52 and 54 preferably are loosely received within the rear tracks 56 and 58 , respectively, permitting the dolly dropdown box drawer assembly 22 to move relative to the dolly dropdown box drawer support frame 24 . The rear tracks 56 and 58 each has a rear portion 64 and 66 preferably each rectangular in shape that each transitions into a front portion 68 and 70 each arcuate in shape, thus permitting rear track follower assemblies 52 and 54 to move (within rear tracks 56 and 58 , respectively) forward from a closed position (see FIGS. 1, 4 , 12 , and 17 ) along rear portions 64 and 66 to an intermediate position (see FIGS. 5,13 , and 14 ) and then to arc along front portions 68 and 70 upwardly and forwardly from the intermediate position (see FIGS. 11 and 15 ) to an open position (see FIGS. 2, 7 , 9 , 10 , and 16 ). Each rear portion 64 and 66 is linearly aligned with a front track 48 and 50 on a support end side walls 38 and 40 , respectively. [0035] When the dolly dropdown box drawer 20 is in a closed position, the drawer bottom wall 34 is substantially in a vertical plane and when the dolly dropdown box drawer 20 is in an open position, the drawer bottom wall 34 is substantially in a horizontal plane (see FIG. 2,7 , 9 , and 16 ). When a towing dolly 10 is within an open dolly dropdown box drawer 20 , the dolly rests on the inner surface of the drawer bottom wall 34 . When a towing dolly 10 is within a closed dolly dropdown box drawer 20 , the dolly rests on the inner surface of the drawer back wall 30 . [0036] As shown in FIGS. 1, 3 to 10 , and 12 to 17 , the dolly dropdown box drawer 20 can optionally be equipped with a selectively operable conventional latching mechanism 72 , having a latching handle mechanism 74 with the latching mechanism fastened to and through the bottom wall 34 in order to secure the drawer in the closed position. Preferably, the latching mechanism 72 includes a pair of shaped sliding rods 76 and 77 that are selectively actuated by the latching mechanism to move horizontally through a pair of rod apertures 78 in the drawer side walls 26 and 28 , respectively and into a pair of rod receiving apertures 80 predrilled in the support end side walls 38 and 40 , and thereby securing the dolly dropdown box drawer assembly 22 within the dolly dropdown box drawer support frame 24 when in the closed position. The shaped sliding rods 76 and 77 are shaped to allow horizontal movement of the rods by the latching mechanism 72 without physical interference with the movement of the rods by a towing dolly 10 resting in the drawer 20 . [0037] The dolly dropdown box drawer 20 can optionally include a drawer pull handle 82 (see FIGS. 1 to 6 , and 17 ) formed into the outer surface of the drawer bottom wall 34 to assist a driver in opening and closing the drawer. [0038] The dolly dropdown box drawer 20 can additionally include a pair of spaced and opposed dolly dropdown box drawer support frame end covers 84 that can each be removably fastened by at least one bolt 86 through at least one corresponding end cover aperture 87 to at least one bolt receiving aperture 88 on the support end side walls 38 and 40 , respectively. [0039] Preferably each front track follower assembly 44 and 46 comprises a capscrew 90 that extends through and rotatably retains a ball bearing assembly 92 on the capscrew with the capscrew engaging a front threaded bore 94 in each of the drawer side walls 26 and 28 , respectively. [0040] Preferably each rear track follower assembly 52 and 54 comprises a capscrew 96 that extends through and rotatably retains a ball bearing assembly 98 on the capscrew with the capscrew engaging a rear threaded bore 100 in each of the drawer side walls 26 and 28 , respectively. [0041] The ball bearing assemblies 92 and 98 make movement of the drawer 20 from a closed position to an open position and the reverse easier. The ball bearing assemblies 92 and 98 roll along respective front tracks 48 and 50 and rear tracks 56 and 58 . [0042] The physical configurations of the front tracks 48 and 50 and the rear tracks 56 and 58 on a respective support end side wall 38 and 40 cooperate to preclude the entry of the rear track follower assemblies 52 and 54 into the front portions 68 and 70 until the front track follower assemblies 44 and 46 descend into the front track detent depressions 60 and 62 . [0043] A double headed arrow a 1 in FIG. 12 indicates the directions of lateral movement of the dolly dropdown box drawer assembly 22 from a closed position to an intermediate position. [0044] A double headed arrow a 2 in FIG. 15 indicates the directions of rotational movement of the dolly dropdown box drawer assembly 22 about the axis of the front track follower assemblies 42 and 44 from an intermediate position to an open position. [0045] The dolly dropdown box drawer support frame 24 may further comprise a support frame back wall 102 , the frame back wall depending down from a rear edge of the intermediate top wall portion 42 and bridging between a pair of rear edges of the end side walls 38 and 40 . [0046] The dolly dropdown box drawer support frame 24 may further comprise a support frame bottom wall 104 preferably rectangular in shape, the frame bottom wall bridging between a pair of lower edges of the end side walls 38 and 40 and extending forward from the support frame back wall 102 towards a point on each end side wall just before the beginning of the front track detent depressions 60 and 62 . [0047] Preferably, the front tracks 48 and 50 and the rear tracks 56 and 58 are cut into the support end side walls 38 and 40 using a computer controlled plasma cutting table. [0048] Alternatively, the front track follower assemblies 44 and 46 may comprise a pair of spaced and opposed pins that project from the drawer side walls 26 and 28 . [0049] Alternatively, the rear track follower assemblies 52 and 54 may comprise a pair of spaced and opposed pins that project from the drawer side walls 26 and 28 . [0050] The preceding description and exposition of the invention is presented for purposes of illustration and enabling disclosure. It is neither intended to be exhaustive nor to limit the invention to the precise forms disclosed. Modifications or variations in the invention in light of the above teachings that are obvious to one of ordinary skill in the art are considered within the scope of the invention as determined by the appended claims when interpreted to the breath to which they fairly, legitimately and equitably are entitled.

A dolly dropdown box drawer is disposed below a bed or a frame of a tow truck along each side of the truck near a driver's cab for the storage and safeguarding of a pair of towing dollies with one on each side of the truck. Each drawer pulls out laterally and then tilts and arcs downward at the front end of the drawer to provide ready and convenient access to a towing dolly at a level below waist level of a tow truck driver who desires to use the towing dolly during a recovery operation conducted regarding a motor vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a U.S. National Stage Application of International Application No. PCT/EP2015/078442 filed Dec. 3, 2015, which designates the United States of America, and claims priority to DE Application No. 10 2014 225 416.7 filed Dec. 10, 2014, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD [0002] The present disclosure relates to filters. Teachings thereof may be embodied in a filter assembly, e.g., a filter assembly for filtering output currents from a voltage converter. BACKGROUND [0003] Voltage converters are often used in power-electronics fields, e.g., in on-board electrical systems of motor vehicles having two or more on-board electrical system branches, in which different voltage levels prevail and in which a voltage at one voltage level is converted in a unidirectional or bidirectional manner into a voltage at another voltage level. For design reasons, output currents from these voltage converters contain AC voltage components which can lead to functional faults in the electrical or electronic components which are connected downstream. Therefore, radio interference-suppression limit values are provided, e.g., in the automotive sector, for the output currents from voltage converters. [0004] To avoid the functional faults due to fluctuating output currents from the voltage converters, the output currents from the voltage converters are filtered before they are passed on to the electrical or electronic components which are connected downstream. To this end, filter assemblies (e.g., EMC filters (electromagnetic compatibility)) are provided in the voltage converters, said filter assemblies weakening or filtering the AC voltage components in the output currents from the voltage converters. SUMMARY [0005] Some voltage converters are more compact and save more installation space while having the same or a better functionality. The teachings of the present disclosure may be embodied in a filter assembly that reduces the need for installation space while having the same or a better filter action. [0006] For example, a filter assembly (FA) may comprise: a current conductor (SL) with a curved profile for conducting a current; a first ferrite body (FK 1 ) and a second ferrite body (FK 2 ); a recess (AN 1 , AN 2 ) in the first ferrite body (FK 1 ) and/or the second ferrite body (FK 2 ) with a curved profile; wherein the first ferrite body (FK 1 ) and the second ferrite body (FK 2 ) jointly surround the current conductor (SL), and the current conductor (SL) extends along the recess (AN 1 , AN 2 ). [0007] In some embodiments, the recess (AN 1 , AN 2 ) and the current conductor (SL) are matched to one another in terms of their respective profiles and also in terms of their respective cross sections in such a way that the current conductor (SL) fits into a hollow space (HR), which is formed by the recess (AN 1 , AN 2 ) of the first ferrite body (FK 1 ) and/or of the second ferrite body (FK 2 ), between the first ferrite body (FK 1 ) and the second ferrite body (FK 2 ). [0008] In some embodiments, the first ferrite body (FK 1 ) and the second ferrite body (FK 2 ) together have a center line which corresponds substantially to a center line (ML) of the current conductor (SL) which extends in the direction of extent (ER) of the current conductor (SL). [0009] In some embodiments, there is an air gap (LS) between the first ferrite body (FK 1 ) and the second ferrite body (FK 2 ), which air gap extends substantially in the direction of extent (ER) of the current conductor (SL). In some embodiments, the one air gap (SL) extends substantially parallel to the center line (ML). [0010] In some embodiments, the first ferrite body (FK 1 ) and/or the second ferrite body (FK 2 ) are each integrally formed. [0011] In some embodiments, the current conductor (SL) has at least one integrally formed portion (AF) which extends away from the center line (ML) and has an exposed end (ED), and the first ferrite body (FK 1 ) and/or the second ferrite body (FK 2 ) have/has at least one further recess (AN 3 ) through which the at least one integrally formed portion (AF) extends, wherein the exposed end (ED) forms an electrical contact to the current conductor (SL). [0012] As another example, a voltage converter, in particular for an on-board electrical system of a vehicle, may comprise a voltage converter circuit for providing output currents and a filter assembly (FA) as described above for filtering the output currents which are provided by the voltage converter circuit, wherein the current conductor (SL) of the filter assembly (FA) is electrically conductively connected to an output of the voltage converter circuit. BRIEF DESCRIPTION OF THE DRAWINGS [0013] An exemplary embodiment of the invention is described in more detail below with reference to the appended drawing, in which: [0014] FIG. 1 is a schematic exploded illustration of a section of a filter assembly according to one embodiment of the invention; and [0015] FIG. 2 is a schematic illustration of a side view of a section of the filter assembly illustrated in FIG. 1 . DETAILED DESCRIPTION [0016] The teachings of the present disclosure may be embodied in a filter assembly. For example, a filter assembly may comprise a current conductor which has a curved (bent or kinked) profile and is designed for conducting a current (for example an output current from a voltage converter). In some embodiments, the filter assembly also comprises a first ferrite body and a second ferrite body which each have a curved profile and jointly (substantially) surround the current conductor. In this case, the first ferrite body and/or the second ferrite body have at least one recess which likewise has a curved profile and extends along the current conductor. The profile of the ferrite bodies, in particular the profile of the recess in said ferrite bodies, may correspond to the profile of the current conductor. A curved design of the current conductor allows a flexible design, which is matched to the available installation space, of the current conductor and also of the two ferrite bodies and therefore a construction of the filter assembly such that installation space is saved while having the same total inductance of the filter assembly and therefore the same filter action, or a higher total inductance and therefore a better filter action with the same installation space of the filter assembly. [0017] The first ferrite body and/or the second ferrite body each form one of two ferrite core halves which, owing to their curved profiles, can jointly surround the current conductor in spite of its curved profile. This allows, in particular, the current conductor to be continuously surrounded in a manner extending over the curved extent of the current conductor by a single ferrite core (which consists of two ferrite core halves), said surrounding allowing a higher total inductance overall for the filter assembly and therefore a better filter action in comparison to a current conductor being surrounded in sections by a plurality of ferrite cores which are physically separate from one another. In this case, the term “jointly surround” means that the two ferrite bodies jointly form the same ferrite core (which surrounds the current conductor) and jointly surround substantially the same section of the current conductor. The surrounding runs around the current conductor in the circumferential direction. [0018] The curved profiles of the two ferrite bodies additionally allow the entire, exposed installation space in the filter assembly around the current conductor to be filled with the ferrite material, as a result of which the cross-sectional area of the ferrite core through which the magnetic field flows is considerably increased. A relatively high total inductance for the filter assembly is achieved in the filter assembly with the same installation space as a result. In addition, the saturation behavior of the filter assembly can be managed substantially better. This allows the filter assembly to be shaped such that more installation space is saved while having the same or even a better filter action. [0019] Therefore, a high total inductance for high useful currents (which are to be filtered) can be realized with the above-described filter assembly. Filter assemblies of this kind can therefore be used, in particular, in electrical systems, such as in an on-board electrical system of a hybrid electric vehicle or electric vehicle, where high power densities prevail but only small installation spaces are available. [0020] The recess and the current conductor may be matched to one another in terms of their respective profiles and also in terms of their respective cross sections in such a way that the current conductor fits substantially into a hollow space, which is formed by the recess, between the first ferrite body and the second ferrite body. The recess and the current conductor may have substantially the same curved profile or the same curved shape, which curved profile or curved shape substantially allows the current conductor to be arranged in the recess with an accurate fit and allows the current conductor to be surrounded by the two ferrite bodies with an accurate fit. [0021] The recess may substantially form a groove-like design. The groove can have, for example, a rectangular, trapezoidal or semicircular cross section. [0022] The first ferrite body and the second ferrite body together (therefore the ferrite core) may have a center line which corresponds substantially to a center line of the current conductor which extends in the direction of extent of the current conductor. In this case, the center line of the first ferrite body and of the second ferrite body or of the ferrite core is a collection of all of the centroids of the cross sections of the two ferrite bodies or of the ferrite core which comprises these two ferrite bodies. [0023] In some embodiments, the first ferrite body and the second ferrite body may be of symmetrical design around their common center line which likewise extends in the direction of extent of the current conductor. The center line corresponds, in particular, to the area centroids of the ferrite bodies (jointly). [0024] The two ferrite bodies and the current conductor may have the same curved profile or the same curved shape, which curved profile or curved shape allows cross sections which are symmetrical along the elongate direction of extent of the current conductor. [0025] The filter assembly may comprise a first current connection and a second current connection, wherein the current conductor extends from the first current connection to the second current connection and electrically connects the first current connection and the second current connection to one another. The first ferrite body and the second ferrite body may likewise extend substantially from the first current connection to the second current connection. [0026] The filter assembly may have at least one air gap between the first ferrite body and the second ferrite body, which air gap extends substantially in the direction of extent of the current conductor. In some embodiments, the at least one air gap extends substantially parallel to the center line. [0027] Owing to the at least one air gap, an open magnetic circuit is formed around the current conductor, as a result of which, in turn, the saturation behavior of the two ferrite bodies (of the ferrite core) or of the filter assembly is weakened and therefore improved. The saturation behavior can be adjusted as desired by correspondingly changing the shape and the size of the at least one air gap, such as the gap width for example. [0028] In some embodiments, the first ferrite body and/or the second ferrite body are each integrally formed. In some embodiments, the current conductor has at least one integrally formed portion which extends away from the center line and, for its part, has an exposed end for establishing electrical contact to the current conductor. In some embodiments, the first ferrite body and/or the second ferrite body have/has at least one further recess through which the at least one integrally formed portion extends. [0029] The integrally formed portions can serve, in particular, as current taps for discharge capacitors. A filter assembly with adjustable partial inductances, which can be adjusted in accordance with the application by forming corresponding electrical contacts to the selected integrally formed portions, can be provided by varying the number of integrally formed portions and points on the two ferrite bodies where said integrally formed portions are integrally formed. [0030] Some embodiments may include a voltage converter. In some embodiments, the voltage converter comprises a voltage converter circuit for providing output currents and an above-described filter assembly for filtering the output currents from the voltage converter circuit, wherein the current conductor of the filter assembly is electrically conductively connected to a positive output connection of the voltage converter circuit. [0031] FIG. 1 shows a schematic exploded illustration of a section of a filter assembly FA for a DC/DC converter, not illustrated in the figure. The filter assembly FA is electrically connected between a positive output connection of a voltage converter circuit, not illustrated in the figure, of the DC/DC converter and an output connection of the DC/DC converter and is designed to filter AC voltage components in the output currents which are provided by the voltage converter circuit and to pass on the filtered output currents to the output connection of the DC/DC converter. [0032] The filter assembly FA comprises a current conductor SL (only a section of the current conductor SL is illustrated in the figure) to conduct output currents from the voltage converter circuit to the output connection of the DC/DC converter and, in the process, to filter the AC voltage components in the output currents. [0033] The current conductor SL comprises a main body GK which is substantially composed of a punched strip of a copper alloy and, to reduce the installation space of the filter assembly, is designed such that it is curved in an L shape or extends along an L-shaped center line ML. The current conductor SL further comprises three rod-like integrally formed portions AF which are composed of the same copper alloy and extend laterally from the main body GK of the current conductor SL and perpendicular to the center line ML. In some embodiments, the three integrally formed portions AF are punched at the same time as the current conductor SL is punched out and are therefore integrally formed with the main body GK. The integrally formed portions AF serve to establish electrical contacts from the current conductor SL to discharge capacitors KD, which will be described below, and each have an exposed end ED for forming said electrical contacts. [0034] The filter assembly FA further comprises a first ferrite body FK 1 and a second ferrite body FK 2 , wherein the two ferrite bodies FK 1 , FK 2 are of symmetrical design in relation to one another substantially around the center line ML of the current conductor SL. [0035] The two ferrite bodies FK 1 , FK 2 each have a groove-like recess AN 1 , AN 2 on respective surfaces which face the current conductor SL, said groove-like recesses being of symmetrical design in relation to one another around the center line ML of the current conductor SL. [0036] The shapes and cross sections of the current conductor SL and of the two recesses AN 1 , AN 2 are matched to one another in such a way that the two recesses AN 1 , AN 2 form a hollow space HR which can just accommodate the current conductor SL and which is also just filled by the current conductor SL. The two ferrite bodies FK 1 , FK 2 therefore jointly form a single ferrite core which virtually completely surrounds the current conductor SL in its direction of extent ER. [0037] In some embodiments, the filter assembly FA further comprises a circuit carrier ST for mechanically fastening the current conductor SL and the two ferrite bodies FK 1 , FK 2 . The filter assembly FA also comprises three above-mentioned discharge capacitors KD which are arranged and mechanically fastened on the circuit carrier ST. The three discharge capacitors KD are each electrically connected to one of the three integrally formed portions AF and form a low-pass filter with n topology with the current conductor SL and the two ferrite bodies FK 1 , FK 2 . [0038] FIG. 2 is a schematic illustration of the side of the filter assembly FA illustrated in FIG. 1 (or a section of the filter assembly FA) in an assembled state. [0039] In the assembled state, the two ferrite bodies FK 1 , FK 2 completely surround the current conductor SL, apart from an air gap LS, in its circumferential direction. The air gap LS extends substantially parallel to the center line ML of the current conductor SL. The air gap LS improves the saturation behavior of the filter assembly FA and therefore allows a relatively high useful current to be filtered. [0040] In this case, the integrally formed portions AF on the current conductor SL protrude through corresponding recesses AN 3 on the second ferrite body FK 2 out of the hollow space HR and are fastened to the circuit carrier ST by means of the exposed ends ED and are electrically conductively connected to conductor tracks on the circuit carrier ST, which conductor tracks lead to the respective corresponding discharge capacitors KD and are electrically connected to corresponding current connections of the discharge capacitors KD. [0041] The curved shapes of the current conductor SL and of the two ferrite bodies FK 1 , FK 2 allow a construction of the filter assembly FA such that installation space is saved. The designs, which are matched in terms of shape and cross section, of the current conductor SL and of the two recesses AN 1 , AN 2 on the two ferrite bodies FK 1 , FK 2 allow an integral ferrite core to be formed, which integral ferrite core can completely surround the current conductor SL over virtually the entire extent of the current conductor SL in spite of the curved shape of said current conductor. This allows a relatively high total inductance of the filter assembly FA.

The present disclosure relates to filters. Teachings thereof may be embodied in a filter assembly, e.g., a filter assembly for filtering output currents from a voltage converter. For example, a filter assembly may include: a current conductor with a curved profile; a first ferrite body; a second ferrite body; and a recess with a curved profile defined in at least one of the first ferrite body and the second ferrite body. The first ferrite body and the second ferrite body may combine to surround the current conductor and the current conductor may extend along the recess.

CROSS REFERENCE TO RELATED APPLICATION This application claims priority to German application number 101 213 22.0 filed May 2, 2001. FIELD OF THE INVENTION The invention relates to a data transmission system having distributed control functionality for machine tools and production machines, and robots, hereinafter referred to generally as machines, and further having a networked movement control system which controls complex processes. BACKGROUND OF THE INVENTION A data transmission system which can be used for machine tools, production machines, and robots, is disclosed in the document “Standardisierter Feldbus für die elektrische Antriebstechnik” [Standardized fieldbus for electrical drive technology], VDI Reports 844, “SERCOS Interface” report, page 69 et seq. The SERCOS interface allows time-controlled bus access to drives. The data messages which are intended for the individual drives are in this case sent in a fixed time frame. An open-loop or closed-loop control system carries out the master function (control functionality) and sends a synchronization signal in time with the cycle time, in response to which the individual drives, i.e., the slaves (secondary functionality), transmit their information to the master. A drive concept for a printing machine without a shaft is disclosed in WO 97/11848. There, information which ensures that the angles of the drives are synchronized during printing rotation is transmitted exclusively via a synchronization bus. Today, it is becoming increasingly important to provide machines, such as machine tools, production machines, and robots, with a network data communications structure, in order to allow production data to be gathered, evaluated and distributed. It is also frequently necessary to match machine units or subunits, and robots, to one another in a production process. SUMMARY OF THE INVENTION The object of the present invention is to provide information for movement control systems, which simultaneously control complex processes in networked machine tools, production machines, and robots, in addition to existing data links. This object is achieved through the discovery that information relating to movement control can be interchanged by means of real-time, cross-communication between the control functional units. All movement control systems which control complex processes can thus react simultaneously to relevant events in a matched manner. In a preferred embodiment of the present invention, real-time cross-communication is carried out using Ethernet links. Using Ethernet makes it is possible to use known bus protocols. Particularly when using fast Ethernet, the very short bus cycles used can result in a wider dynamic range due to the movement control system controlling the complex processes. The wider dynamic range advantageously makes it possible to stabilize process discrepancies more quickly. In a further preferred embodiment of the present invention, the control functional units are synchronized by means of Ethernet real-time cross-communication. This enables the stringent requirements for synchronized running to be satisfied, since the master drives can be matched in real time. In yet a further preferred embodiment of the present invention, data and synchronization signals from drive regulators are interchanged with an associated control functional unit using Ethernet real-time communication. Matching of all the drive regulators in a drive group using real-time Ethernet advantageously makes use of all the conventions defined in an Ethernet, and allows real-time matching of all the drives in a group. Thus, for example, high-precision and low-error position control actions can be carried out. One preferred use of the present invention is in printing machines. In modern printing machines there are a range of individually driven rotating machine elements which are dependent on one another and are matched to one another. A disturbance in a driven machine element in a printing machine can thus also be reported immediately, that is to say in real time, to other machine elements. All movement control systems controlling complex processes can react simultaneously to the disturbance in a matched manner and, for example, can avoid paper jams and torn paper webs. Printing machine downtimes can thus be minimized. DRAWINGS The invention is described in greater detail below and in the context of the drawing, in which: The single FIGURE is a schematic layout of a printing machine incorporating the invention. DETAILED DESCRIPTION OF THE INVENTION In the printing machine illustrated in the drawing, paper webs PB 1 to PB 3 run from paper rolls P 1 to P 3 through printing units D 1 to D 3 , and to a folding apparatus F. After passing through the printing unit D 1 , the paper web PB 1 also passes through further processing units; however, they are not shown in the drawing. Thus, in the drawing, the paper web PB 1 ends in a dashed line. Each printing unit D 1 to D 3 is represented in the illustration by an approximately H-shaped outer contour. The printing units D 1 to D 3 each contain ten cylinders, which are arranged in two groups of five cylinders each. The cylinders represent all the cylindrical or wheel-like machine elements in respective printing units D 1 to D 3 . The paper webs PB 1 to PB 3 run via these cylinder groups, which constitute printing points in the printing units D 1 to D 3 . A printing point essentially comprises a rubber cylinder, a plate cylinder and an inking and moistening mechanism. Each printing point can print ink on one side. All the printing points whose printed paper webs PB 1 to PB 3 are passed to folding apparatus F, are included in a rotation process. In this case, the printing units D 1 to D 3 are normally accommodated in printing towers. Each individually driven cylinder has an associated drive with a respective drive regulator A 1 to A 35 . Each group of drive regulators, A 1 to A 10 , A 11 to A 20 and A 26 to A 35 of respective printing units D 1 to D 3 and A 21 to A 25 for the rotating machine elements of the folding apparatus F has one drive regulator, A 1 , A 20 , A 21 and A 26 with a control functionality LF 1 to LF 4 , for each group. Each group of drive regulators are networked intrinsically in the form of a ring. However, an important feature is that an individual drive regulator A 1 , A 20 , A 21 and A 26 with control functionality LF 1 to LF 4 , is available for each group. Any other data networking which can be carried out within a group is thus also possible. This also includes, for example, serial or star linking. The drive regulators A 1 , A 20 , A 21 and A 26 which have the control functionality LF 1 to LF 4 , are represented by a rectangle drawn with a thicker line than the other regulators. Each of the control functional units LF 1 to LF 4 is coupled to a respective one of associated control computers L 1 to L 4 . The control computers L 1 to L 4 are networked in a control computer communication system by links LK 1 to LK 3 and illustrated in the drawing by dashed lines. Other embodiments of the data networking are also possible. A control computer L 1 to L 4 carries out higher-level process organization and, in the process, normally defines data or parameters that are not time-critical. Thus, for example, the control computers L 1 to L 4 can be used to define the printing units D 1 to D 3 via which a paper webs PB 1 to PB 3 will run, and which drives are intended to run synchronously to one another. In the event of a fault, an operator of a printing machine thus has flexibility to decide which of the printing units D 1 to D 3 will be used. However, this also requires the capability to pass information relating to movement control flexibly to individual printing units D 1 to D 3 . According to the present invention, this is achieved by cross-communication Q 1 , Q 2 and Q 3 . Cross-communication Q 1 to Q 3 is a data link with real-time capability and thus ensures that essential information is available at all movement control points simultaneously. This includes, for example, synchronization and error signals, and signals which necessitate immediate action. In what follows, it is assumed that a specific fault in the folding apparatus F can be rectified by reducing the speed of the paper through the system. Once this fault has been detected, the drive A 21 with the control functionality LF 3 of the folding apparatus F transmits a speed reduction signal to other control functional units LF 1 , LF 2 and LF 4 . The control functional units LF 1 , LF 2 and LF 4 know, via the control computers L 1 to L 4 , which of drive regulators A 1 to A 35 are controlling the movement of the paper webs PB 1 to PB 3 to the folding apparatus F. The respective control functional units LF 1 , LF 2 and LF 4 signal the above-mentioned speed reduction to the appropriate drive regulators. The cross-communication Q 1 to Q 3 in real-time means that all the control functional units LF 1 to LF 4 have this information at the same time. Once a fault has been identified and a counter measure has been initiated, this leads to an immediate reaction at the same time in the drive groups. This advantageously allows an improved printed product quality to be achieved. Since all the control functional units LF 1 to LF 4 are connected by means of real-time cross-communication Q 1 to Q 3 , this ensures that all the information relating to movement control is available all the time throughout the system. Even if the system operator has to reconfigure the system, in terms of the profile of the paper webs PB 1 to PB 3 , as a result of a fault, there is nevertheless no need for him to carry out any rewiring for information distribution. In particular, complex, freely configurable production lines which use machine tools, production machines, and robots in the end profit from the real-time capability of the cross-communication Q 1 to Q 3 . It is even conceivable for such flexibility to be made possible for the first time by the use of cross-communication Q 1 to Q 3 with a real-time capability.

A data transmission system with distributed control functionality for machine tools, production machines, and robots, having a plurality of control functional units, has a respectively networked movement control system which controls the operation of the control functional units in complex processes. Information relating to movement control can be interchanged by means of real-time cross-communication between the control functional units. An Ethernet link can be used for real-time cross-communication. The use of the data transmission system for printing machines also represents an advantageous application of the invention.

This is a continuation application of Ser. No. 08/147,872, filed Nov. 4, 1993 now abandoned, which is a divisional application of Ser. No. 07/776,199, filed Oct. 15. 1991, now U.S. Pat. No. 5,281,456. FIELD OF THE INVENTION This invention relates to insulating ductwork. More specifically, the invention relates to forming lineal corner edging on insulated ductwork and similar structures. BACKGROUND OF THE INVENTION It has been the practice in the insulation of heating and air conditioning ductwork to seal the corners of the ducts, whether straight or curved. Typically, ninety degree angle edging made of either sheet metal, plastic or even paper has been used. The insulation industry has traditionally used tin (plated) edges 2"×2" on corners of ductwork, scroll fans and other essentially square edges. These tin plated edges are held in place with tape or contact adhesive which can be brush applied. Thereafter canvas, plastic, or other suitable decorative fabric is stretched around the structure and glued in place. In the case of canvas, further coatings are painted on to shrink the canvas to a tight fit and seal it to provide an attractive finish. Tin edges or galvanized sheet metal are generally made of approximately twenty-four gauge (0.023") thick material. Murasho Co. Ltd. offers an edging material that is formed in a metal roll consisting of a flat surface with overlapping discrete segments depending from the flat surface at a ninety degree angle. The discrete segments facilitate application of the flat surface on contoured edges. The Murasho product is identified as Roll Kiku-za or squeezed sheet. Similarly, Zeston (Manville Corporation) has marketed a metal end capping product that is essentially the same. A need has arisen for an inexpensive, easy to apply corner edge, starting at 11/2"×11/2" and going up to 3"×3" to accommodate the normal insulation thicknesses used on ductwork and similar structures that are generally 1" to 2" thick (or more). SUMMARY OF THE INVENTION It is an objective of the invention to provide edging material for the corners of ductwork and other conduit structures formed with square or somewhat square corners. It is another object of the present invention to provide polyvinyl chloride edging for ducting. It is a further object of the invention to provide a process for manufacturing polyvinyl chloride edging material particularly well suited for sealing the corners of ducting and similar structures. Accordingly, a flat polyvinyl chloride strip is provided with adhesive on one side, release paper covering the adhesive, and an embossed score line linearly disposed over the length of the strip on the adhesive side. The release paper is severed at the score line to provide two discrete strips of release paper. Application of the strip to corner edges proceeds by cutting the strip to the length desired, bending the strip down its entire length, on the score line, to a 90° angle, removing one of the two release paper strips, adhering the exposed adhesive portion of the strip to the corner edge. The second strip of release paper is then removed and this portion of the strip is pushed down and adhered in place resulting in a 90° (or other angle desired) straight corner edge that covers and seals any raw edges. Where ducts or equipment that are to be edged, turn away from a straight direction, silts can be scissor cut perpendicular to the length of the strip, up to the score line to form segments that are folded along the score line and adhered to the adjacent surface, on the inside radius curves of the article being edged and to itself. DESCRIPTION OF THE DRAWINGS The subject invention will be better understood when viewed with the following drawings wherein: FIG. 1 is a plan view of the edge strip of the present invention; FIG. 2 is a sectional elevational view of the invention applied to one surface of ducting; FIG. 3 is the edging material of FIG. 2 shown fully applied to the ducting; FIG. 4 is a schematic of the process equipment shown forming the edging material of the subject invention; FIG. 5 is a sectional view of the embossing roll assembly taken through line 5--5 of FIG. 4; FIG. 6 is a variation of the process for forming the edging material of the subject invention; and FIG. 7 is the edging material of FIG. 1 applied to an insulated pipe. DESCRIPTION OF THE PREFERRED EMBODIMENT The invention has application in any environment in which angled corners are required to be sealed. However, the present invention will be described principally in the environment of heating, ventilation and air conditioning ducting. As best seen in FIG. 1, the present invention is comprised of a flat strip of polyvinyl chloride edging material 2 having a centrally disposed linear score line 4; a layer of adhesive formed on the adhesive side 8 of the strip on which the score line 4 is located and optional separate release paper strips 12 and 14 to maintain the adhesive layer in an unexposed condition until application of the edging material 2 to the edge to be sealed. The score line 4 facilitates the bending of the strip edging material into separate regions 5 and 7. As seen in FIG. 2, the strip is applied to one surface 16 adjacent to the edge 18 being sealed, in this case ducting 20, after removal of a strip of release paper 12. Thereafter, the strip of release paper 14 is removed and the section of the edging material extending beyond the adhered surface is then cut into discrete segments 22 separated by the cut slits 24. The discrete segments 22 are rotated around the score line 4 and the exposed adhesive surfaces of the discrete segments 22 are pressed against the opposite or complementary surface 26 of the ducting 20 to provide a seal at the duct edge 18, best seen in FIG. 3. The process of forming the edging strip 2 is best seen in FIG. 4 wherein a roll of polyvinyl chloride strip material 28 is formed on an idler mandrel 30, a contact adhesive with silicone paper release tape roll 32 is formed on a separate idler mandrel 34 and the formed edging strip 2 is taken up on a driven mandrel 36. Pressure application rolls 38 are provided to secure the paper release tape to the edging strip and a linear groove adjustable depth embossing roll assembly 40 is provided to form the score line 4. In operation, the driven mandrel 36 pulls the polyvinyl chloride strip and release paper through the pressure application rolls 38 and the embossing roll assembly 40. The pressure application rolls 38 secure the contact adhesive with silicone paper release strips 32 to the adhesive surface 8 of the polyvinyl chloride strip 2 and the embossing roll assembly 40 forms the score line 4 linearly in a centrally disposed location on the strip 2. As best seen in FIG. 5, the embossing roll assembly is comprised of an embossing roller 42 with a continuous embossing ridge 44 and a mating roll 46 with a groove 45 corresponding to the embossing ridge 44 against which the embossing ridge 44 reacts through the strip 2 to form the score line 4. In a variation or modification of the process for forming the corner edge strip 2 of the subject invention, slitting rolls 48 and 50 can be substituted for the embossing roll assembly 40. The slitting rolls 48 and 50, best seen in FIG. 6, are arranged to provide a depth of approximately 0.030 inches when applying the score line 4 to a polyvinyl chloride strip 2. The effect of the slitting roll is to provide both a score line 4 and also sever the release paper into two separate distinct strips 12 and 14, by stretching the polyvinyl chloride strip and tearing the release paper. The score line 4 on the strip 2, although linearly disposed, can be located off-center. Illustratively, in covering a two inch thick foil faced insulation board, with a four inch corner edge strip 2, a one inch coverage over the foil by the corner edge strip 2 is appropriate with the remaining three inches of the corner edge strip 2 covering the two inches of raw end insulation board and adjacent foil facing. Thus, the strip 2 for that particular application has the linear score line 4 located one inch in from an edge. Practice has shown that polyvinyl chloride identified as rigid, high impact strength PVC having a thickness of 0.005 inch to 0.0625 inch performs well as the edging strip 2. However, light gauge metal of 0.005 inch to 0.020 inch thickness or more can also serve as the edging material. Further, a composite of aluminum fused to rigid polyvinyl chloride known as VINALUM manufactured by Proto Corporation also performs well as the material of the edging strip 2. The depth of the score line 4 is 0.010 to 0.062 inch and preferably 0.030 inch. In another embodiment of the invention the corner edging strip may contain a plurality of score lines 4 linearly disposed over the length of the strip 2 which allows for selective forming of the strip to various edges. For example a four inch wide strip may have five score lines, each score line being disposed at least 1/2 inch from the adjacent score line. The score lines 4 on this embodiment would be located 1/2, 1, 11/2, 2 and 21/2 inches from an edge of the strip 2 with the remaining 11/2 inches of the strip 2 being unscored. The strip may then be bent at any of the score lines to form the desired amount of strip material on each side of the article being edged. The strip 2 with a plurality of score lines 4 is especially suited to edging the terminal ends of insulated pipes. The terminal end of an insulated pipe is edged by bending the strip 2 at one of the plurality of score lines 4 to create a section of the strip 2 corresponding to the thickness of the insulation on the pipe to be edged. For example, for a pipe 70 covered with 11/2 inch insulation, a four inch strip 2 with five score lines at 1/2 inch intervals would be bent at the score line that is 11/2 inches from the edge of the strip 2. The remaining 21/2 inch strip is then applied to the outer perimeter of the pipe insulation 72. The 11/2 inch portion of the strip 2 is then scissor cut into discrete segments 22 by cutting slits 24 into the strip 2. The discrete segments 22 are then adhered to the exposed terminal end of the pipe insulation with adjacent discrete segments overlapping as seen in FIG. 7. Once the pipe insulation is edged the edging may be painted with PVC-type adhesive caulkings such as Celulon®, or Clear as made by Red Devil, Inc. of Union, N.J., or All Purpose Adhesive Caulk as made by MacKlanburg Duncan of Oklahoma City, Okla. The width of strip 2 and number of score lines can be varied to accommodate any pipe insulation thickness or length of lineal pipe covering. According to this embodiment, one or two rolls of the edging material may be carried by a mechanic to cover the raw ends of pipe coverings rather than ordering specific sized end caps or different roll sizes of the Roll Kiku-za type material. Many variations of the present invention will suggest themselves to those skilled in the art in light of the above-detailed description. All such obvious modifications are within the full intended scope of the claims.

The invention relates to a method and an apparatus for forming and applying edging material to the corners of ductwork and other conduit structures.

FIELD OF THE INVENTION [0001] The present invention relates to a method of operating service provider management systems using a content-control and nudging based process to ensure quality and facilitate knowledge build-up. Further, the invention relates to a computer-based service provider management system configured to support such a method. BACKGROUND OF THE INVENTION [0002] Before the method and computer based system of the present invention there was no method or computer-based system using a content-controlled and nudging based process to ensure quality and knowledge build-up that is independent of subsequent quality control and knowledge collection within service provider management organizations. Conventionally such systems has been developed based on best practice frame processes to create an environment of processes and systems for carrying out case management in the best possible way. However, such systems lack the ability to effectively control the system of the case management based on effective processes based on competences and experience due to the complexity of such systems. Thus a need exists to provide a case management system with improved process control to ensure high quality management of service requests in service provider management organizations. DISCLOSURE OF THE INVENTION [0003] On this background, it is an object of the present application to provide a method of operating a service provider management system wherein the workflow when handling a service request is controlled through a set of operational standard processes prompted systematically in a specific order to ensure that users of the service provider management system provides the information intended in the design of the system to achieve the highest possible quality of the service requests handled by the service provider management system. [0004] This object is achieved by providing a method of operating a service provider management system having an operator interface and an input component, said method comprising the steps of: receiving a service request in the system from a requestor being serviced by a service provider; allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields; prompting an operator to input or select facts relating to the service request in the logging input fields; verifying that mandatory logging input fields has been completed before allowing the next step to be initiated; thereafter allocating said portion of the operator interface to a set of predefined initial diagnosis input fields, said set of predefined initial diagnosis input fields comprising mandatory initial diagnosis input fields; prompting an operator to input or select an initial diagnosis in the set of initial diagnosis input fields; verifying that the mandatory initial diagnosis input fields have been completed; thereafter allocating said portion of the operator interface to a set of predefined diagnosis output fields, said set of predefined diagnosis output fields comprising mandatory diagnosis output fields; prompting an operator to input or select a diagnosis output in the set of diagnosis output fields; verifying that the mandatory diagnosis output fields have been completed; issuing a service request reply comprising the diagnosis output; thereafter allocating the portion of the operator interface to a set of closure fields comprising mandatory closure fields; prompting an operator to input or select facts relating to closure in the set of closure fields; verifying that the mandatory closure fields have been completed; closing the service request; and outputting the facts from the mandatory closure fields to a database. [0021] In an embodiment of the method according to the invention, the step of allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields further comprises the steps of: prompting an operator to input or select a service request category; verifying that the service request category has been input or selected, and defining a sequence of the set of predefined logging input fields based on the service request category. [0025] By initially selecting a service request category the workflow may be tailored to the exact service request type, such that the user only has to acknowledge the relevant input fields or have access to additional tools such as category specific dropdown lists or search tools. [0026] In an embodiment the method according to the invention, the service request category is an incident management, a transition management, knowledge management, change management or a request management. [0027] In an embodiment the method according to the invention, the service request category is a change management, a request fulfillment management or an access management. [0028] In an embodiment of the method according to the invention, one or more of the steps of prompting an operator to input or select facts, an initial diagnosis, a diagnosis output or facts relating to closure further comprises the step of: nudging the operator to input or select one or more mandatory or optional fields. [0030] The mandatory input fields required by the system to be input may be further supported to achieve the highest possible quality of the service request management and therefore the method may also comprise a step of nudging the user to input optional fields to increase the quality. Even the step of inputting mandatory input fields may comprise a step of nudging the user e.g. to a specific type of input again to increase the quality of the handling of the service request or to improve the efficiency by which service requests are handled by the method according to the invention. [0031] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more optional fields comprises prompting the operator with information from earlier similar service requests to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input. [0032] An effective nudging step is the prompting of one or more earlier inputs in a specific input field to allow the user to get an idea of the type of input relevant in the input field e.g. length and content of the input. [0033] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more mandatory or optional fields comprises prompting the operator with a direct link to a knowledge database to allow the operator quickly to seek information to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input. [0034] Quick access to a knowledge database may nudge the user to seek information from earlier or similar service requests, which in effect again increases the quality in the handling of the service request. [0035] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more mandatory or optional fields comprises prompting the operator with information from earlier service requests to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input. [0036] In an embodiment of the method according to the invention, the step of allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields further comprises the step of: displaying in the central portion facts from one or more similar service requests in the same service request category. [0038] In an embodiment of the method according to the invention, the method further comprises the steps of: prioritizing the service request by a service request priority; forwarding the service request to a buffer list of service requests; displaying a service request having the highest priority in the central portion. [0042] In an embodiment of the method according to the invention, the step of allocating said portion of the operator interface to a set of predefined initial diagnosis input fields comprises the steps of: allocating a field for a symptom associated with a problem of the service request; allocating a field for a triggering factor of the symptom associated with the problem. [0045] In an embodiment of the method according to the invention, the method further comprises the step of prompting the operator to input or select which inputting fields associated with logging, initial diagnosis, diagnosis output or closure are relevant to future service requests such that the input or selected information from the operator may be made available in a knowledge database. [0046] In an embodiment of the method according to the invention, the operator is prompted to tick off fields of relevance in a tick box associated with each fields, thereby indicating fields which are relevant to future service requests such that the ticked input from the operator may be made available a knowledge database. [0047] In an embodiment of the method according to the invention, the step of allocating said portion of the operator interface to a set of predefined diagnosis output fields further comprises the step of: allocating a direct link to a knowledge database in the portion of the operator interface. [0049] In an embodiment of the method according to the invention, the step of allocating the portion of the operator interface to a set of closure fields comprising mandatory closure fields further comprises the step: allocating a field for a case summary. [0051] In an embodiment of the method according to the invention, the steps of verifying that the mandatory logging fields, mandatory initial diagnosis fields, diagnosis output fields has been completed comprises a step of prompting to the operator that the service request cannot be issued before the mandatory fields has been completed. [0052] In an embodiment of the method according to the invention, the step of allocating the portion of the operator interface to a set of closure fields comprises the step of: allocating a field for a list of open service request having matching or near matching symptoms or triggering factors of the symptoms of a problem of the service request for allowing the operator to solve similar service requests while having the service request and diagnosis steps fresh in mind. [0054] In an embodiment of the method according to the invention, the allocation of said portion of the operator interface is shown on a graphical user interface on a computer screen and said operator input component comprises a keyboard. [0055] In an embodiment of the method according to the invention, the input or selection values of a service request already known in the service management system are automatically discarded and thus not prompted to be input by the operator. [0056] The object above is also achieved by providing a computer-based service provider management system comprising: [0057] an operator interface and an input component; [0058] a processor being configured to control operation of said system including being configured to receive input from an operator through the input component, and to run an application on said system; [0059] said processor further being configured to receive a service request in the system from a requestor being serviced by a service provider; [0060] said processor further being configured to allocate a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields; [0061] said processor further being configured to prompt an operator to input or select facts relating to the service request in the logging input fields; [0062] said processor further being configured to verify that mandatory logging input fields has been completed before allowing the next step to be initiated; [0063] said processor further being configured to thereafter allocate said portion of the operator interface to a set of predefined initial diagnosis input fields, said set of predefined initial diagnosis input fields comprising mandatory initial diagnosis input fields; [0064] said processor further being configured to prompt an operator to input or select an initial diagnosis in the set of initial diagnosis input fields; [0065] said processor further being configured to verify that the mandatory initial diagnosis input fields have been completed; [0000] said processor further being configured to thereafter allocate said portion of the operator interface to a set of predefined diagnosis output fields, said set of predefined diagnosis output fields comprising mandatory diagnosis output fields; [0066] said processor further being configured to prompt an operator to input or select a diagnosis output in the set of diagnosis output fields; [0067] said processor further being configured to verify that the mandatory diagnosis output fields have been completed; [0068] said processor further being configured to issue a service request reply comprising the diagnosis output; [0069] said processor further being configured to thereafter allocate the portion of the operator interface to a set of closure fields comprising mandatory closure fields; [0070] said processor further being configured to prompt an operator to input or select facts relating to closure in the set of closure fields; [0071] said processor further being configured to verify that the mandatory closure fields has been completed; [0072] said processor further being configured to close the service request. [0073] The invention also relates to a computer-based service provider management system comprising a processor configured to control a set of service requests. [0074] Also, in an embodiment of the system according to the invention, the processor is furthermore configured to categorize the service request by a service request category and configured to define a sequence of the set of predefined logging input fields based on the service request category. [0075] Also, in an embodiment of the system according to the invention, the processor is furthermore configured to display in the central portion facts from one or more similar service requests in the same service request category during allocation of the central portion of the predefined area of the operator interface to the set of predefined logging input fields. [0076] Also, in an embodiment of the system according to the invention, the processor is configured to prioritize the service request by a service request priority, forward the service request to a buffer list of service requests and display a service request having the highest priority in the central portion. [0077] Also, in an embodiment of the system according to the invention, processor is configured to prioritize the service request by a service request priority, forward the service request to a buffer list of service requests and display a service request having the highest priority in the central portion. [0078] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a symptom of a problem of the service request and allocate a field for a triggering factor of the symptom of the problem during allocation of the central portion to the set of predefined initial diagnosis input fields. [0079] Also, in an embodiment of the system according to the invention, the processor furthermore is configured to receive inputs from of the operator, when the operator is inputting in fields associated with logging, initial diagnosis, diagnosis output or closure, the inputs indicating fields which are relevant to future service requests such that the indicated input from the operator may automatically enter a knowledge database. [0080] Also, in an embodiment of the system according to the invention, the processor furthermore is configured to receive inputs from of the operator, when the operator is inputting in fields associated with logging, initial diagnosis, diagnosis output or closure, said processor being configured to receive an operator ticking off fields indicating fields which are relevant to future service requests in a ticking box associated with each field such that the ticked input from the operator may automatically enter a knowledge database. [0081] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a direct link to a knowledge database in the central portion during allocation of the central portion to a set of diagnosis output fields. [0082] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a case summary during allocation of the central portion to a set of diagnosis output fields. [0083] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a list of open service request having matching or near matching symptoms or triggering factors of the symptoms of a problem of the service request during allocation of the central portion to a set of closure fields. [0084] Also, in an embodiment of the system according to the invention, the processor is configured to give access to input data from a set of fields having been recognized by a control procedure during subsequent steps. [0085] Further objects, features, advantages and properties of the engine and method of operating an engine according to the present disclosure will become apparent from the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0086] In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which: [0087] FIG. 1 depicts a flow-chart diagram of an embodiment of a process flow of processing a service request, [0088] FIG. 2 a is a flow-chart diagram of a subroutine of the method shown in FIG. 1 , [0089] FIG. 2 b is a flow-chart diagram of a subroutine of the method shown in FIG. 1 , [0090] FIG. 2 c is a flow-chart diagram of a subroutine of the method shown in FIG. 1 , [0091] FIG. 2 d is a flow-chart diagram of a subroutine of the method shown in FIG. 1 , [0092] FIG. 3 is a flow-chart diagram of a subroutine, [0093] FIG. 4 is a flow-chart diagram of a subroutine, [0094] FIG. 5 is a schematic overview of a service provider management system, [0095] FIG. 6 is a screen shot of an operator interface having a central portion display allocated to a set of predefined logging input fields of an electronic processing unit, [0096] FIG. 7 is a screen shot of an operator interface having a central portion display allocated to a set of predefined initial diagnosis input fields of a processing unit, [0097] FIG. 8 is a screen shot of an operator interface having a central portion display allocated to a set of predefined diagnosis output fields of a processing unit, and [0098] FIG. 9 is a screen shot of an operator interface having a central portion display allocated to a set of set of closure fields of a processing unit. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0099] FIG. 1 is a flow-chart diagram of an embodiment of the present invention. FIG. 1 shows a preferred embodiment of the invention wherein the sequence created is preferably created for processing a service request using a service provider management system. [0100] Initially a requestor transmits a service request to the service provider management system. The service request may be any type of service request managed by service provider management systems such as incident managements e.g. software failures, hardware failures, network problems etc. Incident refers to a problem in an existing IT solution. IT departments typically follow more or less the same procedures or lack of procedures when dealing with incidents irrespective of the type of incident, since the process is set out by the service provider management system of the IT or managing departments. Other types of service requests may relate to transition management i.e. the change of existing settings, hardware etc. and the deployment of such. Specific requests in transition management are requests related to release management e.g. related to release, deployment or roll-out of new software or hardware solutions. Other Specific requests in transition management are requests related to changes in standards e.g. related to release, deployment or roll-out of new software or hardware solutions according to new standards. The service request may also relate to knowledge management i.e. the request of a known knowledge item based on prior experience or the request of providing a new knowledge item to solve e.g. a recurring problem etc. The service request may also relate to request management i.e. procedures around the request of new items e.g. new hardware, new software etc. According to the method of the current invention all types of service requests are dealt with using the same generic approach, but the specific handling of different types of service requests may of course be made to depend on the specific type of service request using different subroutines or skipping steps of the method not appropriate to the specific service request. [0101] The service request is received at an operator interface, the service provider management system typically a service provider management system application running on a computer. When the service request is received at the operator interface a set of predefined logging input fields comprising a set of mandatory logging input fields are allocated on a portion of the operator interface. By allocating a portion of the operator interface, the attention of the operator is directed towards a specific set of fields requiring input. The operator is subsequently prompted to input or select facts relating to the service request in the logging input fields. It is an essential aspect of the method, that the operator is prompted to input the facts relating to the current step in the method, to ensure that the service provider management system supports the operator in achieving a specific focus on the current step rather than a later step e.g. showing fields for inputting the solution to the problem. By allocating a portion and preferably a large and central portion of the operator interface to fields of the current logging step i.e. the logging input fields and prompting the operator to input or select facts from the service request in the logging input fields, the quality of the logging of the service request may be controlled. By adding furthermore a step verifying that mandatory logging input fields has been completed before allowing the next step to be initiated, the service provider management system is setup to ensure that the quality of the logging of the facts of the service request is always performed to a required extent. This logging subroutine also shown in FIG. 2 a shows the generic approach of the method i.e. to encourage and nudge the operator to always fill out mandatory operator input, by sequencing the subroutines in an allocation step, a prompting step and a verification step. [0102] Following the logging subroutine (see FIG. 2 a ) are an Initial diagnosis subroutine (see FIG. 2 b ), a Diagnosis output subroutine (see FIG. 2 c ) and a Closure subroutine (see FIG. 2 d ) all having the same structure as the logging subroutine shown in FIG. 2 a of an allocation step, a prompting step and verification step. When the operator is prompted to input or select certain types of information into a set of fields allocated in a portion of the operator interface and the next set of input fields only may be allocated after the fulfillment of at least the mandatory fields, the working process of the operator may be controlled by the service provider management system and not the individual routines of the operator. This significantly enhances the quality of the handling of service requests. Furthermore, the operator may be prompted to use existing knowledge of earlier service requests based on prior input in the service provider management system. Also, the operator may be nudged to fill out non-mandatory fields to improve the quality of the handling of the service request e.g. if the service request regards a computer break down, it might be mandatory to the operator to provide the requestor with a recovery procedure to recover the computer, but the operator may be nudged to inform the requestor of improved back-up procedures to avoid data loss during future computer break downs. This type of nudge may be based on earlier and similar service requests being prompted to the operator, while being prompted to fill out any mandatory fields. [0103] Referring now to FIG. 1 again the portion of the operator interface is subsequent to the verification of the filling of mandatory logging fields allocated to a set of predefined initial diagnosis input fields. When handling service requests of different types in a service provider management system the step of performing an initial diagnosis is very important. The initial diagnosis ensures that the type of service request is determined. [0104] As a result of the input in the initial diagnosis fields the service request may be in some instances be treated as a quick case i.e. a service request which might be dealt with very quickly e.g. due to a prior solution to precisely the same type of service request or if the service request based on the input is found to be very minor. In such cases subsequent steps or input may be automatically input or automatically skipped to reduce time consumption of such cases. Also steps later in the method e.g. diagnosis output steps or closure steps may be automatically input or automatically skipped based on earlier input in order to handle such service requests as quick cases. [0105] Service request management may be improved by requiring prioritization input e.g. during the initial diagnosis or diagnosis output steps. Prioritization of the service requests may in some cases be handled well by an operator performing the initial diagnosis, however, in some cases the severity of the service request are not properly assessed before an expert handles the request later in the process. Therefore, prioritization of the service requests may be performed advantageously during one or more subroutines to ensure an optimal prioritization if initial prioritizations are inadequate. [0106] Prioritizations may be used to escalate processes or routines and operators inputting complementary information may also be viewed as a prioritizing step since the input may escalate the processes or routines based on the input. [0107] The operator is not necessarily a person but may be a group of persons. The work flow for the operators may be such that all operators participate in the initial logging steps i.e. inputting or selecting the facts related to the service request, whereas the initial diagnosis and subsequent steps may only be dealt with by operators handling a specific type of service requests. [0108] The operator may during the logging subroutine or the initial diagnosis subroutine accept the task of handling the service request if he feels competent. Also, the initial diagnosis may be performed by an operator executive of a group of operators and comprise a step of selecting a specific operator to handle the service request. [0109] The basic work of handling the service request to be able to provide the requestor with a service request reply is carried out during the Diagnosis output routine. The diagnosis output fields comprise the mandatory diagnosis output fields which are essential when making a reply to the service request e.g. in a request management examples of mandatory diagnosis output fields could be: is the request of the requested item granted, is the requested item ordered, when is the expected delivery of the requested item etc. When all mandatory diagnosis output fields have been input or selected by the operator, a service request reply may be issued to the requestor. [0110] When the service request reply has been issued to the user to the requestor the portion of the operator interface is allocated to a set of closure fields comprising mandatory closure fields. The operator is prompted to input or select facts relating to closure in the set of closure fields. This step of handling service requests is often neglected since the requestor has already received a response. In periods of high activity the operator therefore tends to neglect the closure of the handling of the service request. However, for the service provider the closure step is often essential to ensure a high level of quality in the handling of service requests and furthermore from a system point of view a time saver since future service requests are better and quicker handled if relevant details on solutions or problems are well handled in the closure steps. When the operator has input or selected at least the mandatory closure fields the mandatory closure fields are verified by the system and the service request is finally closed. [0111] As shown in FIG. 2 a - 2 d the method shown in FIG. 1 comprise four different generic subroutines: Logging FIG. 2 a , Initial diagnosis FIG. 2 b , Diagnosis Output FIG. 2 c and Closure FIG. 2 d . Each of these subroutines comprises at least the same generic steps of allocating a set of input fields in a portion of the operator interface, prompting the operator to input and select facts and subsequently verifying that the mandatory fields have been completed. This construction of the subroutines provides a method of operating a service provider management system, where the operator is continuously prompted to have the “right mindset” of his current task. Furthermore, is he not only prompted continuously to have the “right mindset”, but the subroutine also verifies if the operator made the required input in at least the mandatory fields to ensure a high quality in the handling of service requests. The steps of consecutively going through such subroutines as shown in FIGS. 2 a - d resemble a user interface of a GPS device used in cars for determining the route of travel. The user interface keeps changing view to be exactly the extract of the route directly in front of you. The mindset of the driver is controlled by only showing the upcoming part of the route and only indicating when and where the next turn is located. In this way the mindset of the driver is controlled to focus only on the upcoming navigation and not give the next navigation command until the driver carried out the former. [0112] Initially an operator inputs or selects a set of facts relating to the service request e.g. facts of an incident or transition. The input to the logging routine as shown in FIG. 1 is typically performed by the operator of the service provider management system, since the operator is the professional compared to the requestor. The requestor may however be forced to input the service request in a specific form to ease the work of the operator, where after the operator checks the input or selection of the requestor. [0113] FIG. 3 shows an embodiment according to the invention wherein the step of allocating logging input fields comprises three steps in order to specifically base the input fields and the sequence of the input fields using a specific subroutine. When allocating the logging input fields according to this embodiment the operator is initially prompted to select the service request category, the selection is subsequently verified and the sequence of the logging input fields is thereafter defined based on the service request category. To allow the method of operating the service provider management system to be able to operate various categories of service requests within the same system and still maintain tailored processes and subroutines for different categories of service requests, the service request category may be required as input during the initial logging of the service request. Same approach may be used to differentiate different subcategories of service requests in any other step of the method, e.g. when the service request regards an incident management, the service request category may be chosen during the step of allocating the logging input fields to be in an “incident management” category, and then subsequently the system may require the operator to input a subcategory during the initial diagnosis step e.g. handling of a “hardware failure” subcategory and maybe even further categorized e.g. during the diagnosis output step to a more narrow subcategory e.g. “switch failure”, “hard disc failure” etc. [0114] In some service request management systems operators inputting e.g. the initial diagnosis may not have sufficient knowledge to reach the conclusions or even the right field of the diagnosis output resolution, since these may require deeper insights into some details not available to all operators. However, to minimize non-productive time of the operators any early assessments or speculations of operators handling the initial diagnosis may be input as hypothesis input to improve the speed of the operator handling a subsequent step e.g. the diagnosis output. [0115] As described the steps of the method according to the invention may comprise further steps to increase the quality of the handling of service requests by certain subroutines. FIG. 4 shows an embodiment according to the invention wherein the step of allocating initial diagnosis input fields comprises two steps in order to force or nudge the operator to handle the initial diagnosis by indicating the symptom associated with a problem e.g. a user requesting help with his computer, since the computer keeps crashing. The problem of the service request is evidently a computer not working optimally, the symptom is that the computer keeps crashing. Since such problem and symptom may cover a wide variety of triggering factors, the operator may already in the initial diagnosis have information about a triggering factor of the symptom e.g. the user may have provided information on a specific software program associated with the crashes or loud sound indicating hardware failures etc. If the operator is able to indicate a triggering factor already in the initial diagnosis step, the handling of the service request may be sub-optimized since a given operator handling the diagnosis output may be handed only service requests requiring the specific expertise of this operator. Same approach may be used to optimize other steps or sub routines of the method. [0116] During an operators input of the initial diagnosis input fields a specific resolution of the output may be requested and a qualified resolution may be searched to accommodate the request. Iterations may be required to achieve the requested specific resolution if the accessible resolution is inadequate e.g. maybe the generic problem was solved earlier, but the specific problem is different and must be handled differently than the accessible resolution. In such cases the operator is then required to input a qualified resolution to the specific problem or in case the problem is not solvable inputs a “no-resolution”, which may be communicated back to the requestor of the service request. This approach may furthermore be used to set up a well-organized hierarchy of qualified resolutions, which may be used systematically in future handlings of service requests. [0117] FIG. 5 is a schematic overview of a service provider management system comprising four different service request categories i.e. incident, transition, knowledge and request managements. These are not to be considered limiting to the scope of the invention, but are examples of typical categories of service requests handled in service provider management systems. Even more categories may be handled using the same method and service provider management system. Since the operator interface is controlled to primarily comprise fields intended to be handled by the operator in that particular part of the process, the operator is not affected by the system handling a wide variety of service request categories. If the operator is not well suited to fill out the required input he may forward it to the relevant operators or send it back for re-categorization. In this way the daily work of the operator may also be more convenient since stressful tasks relating to the handling of service requests outside the competences of the operator may be more or less avoided. [0118] FIGS. 6-9 shows a series of screen shots of an operator interface having a central portion allocated to specific fields of interest during the process thereby controlling the operator to fill in the needed information to ensure a good, thorough and consistent processing of service requests by a service provider and a controlled collection of the knowledge build-up by earlier inquiries. [0119] In some methods of operating service request management systems specific steps of the method may involve the requestor to input additional information required to solve certain issues with respect to the service request. [0120] Reminders may be used in the method or systems according to the invention to remind operators or requestors to input a certain mandatory or non-mandatory input. Especially mandatory input may be ensured be specific subroutines reminding of missing input. [0121] In some embodiments of the invention the requestor may act as operator. [0122] The term “comprising” as used in the claims does not exclude other elements or steps. The term “a” or “an” as used in the claims does not exclude a plurality. The single processor, device or other unit may fulfill the functions of several means recited in the claims. [0123] The reference signs used in the claims shall not be construed as limiting the scope. [0124] Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention. [0125] While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species, and the various beneficial features may be employed in embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.

A method of operating service provider management systems using a content-control and nudging based process to ensure quality and facilitate knowledge build-up and a computer-based service provider management system configured to support the method.

STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon. FIELD OF THE INVENTION This invention relates to optical computing and optical signal processing realizations including the provision of a general purpose optical computer. BACKGROUND OF THE INVENTION In 1937, A. Turing proved that a "universal digital computer", having a finite number of components could be realized. This Universal Turing Machine (UTM) could be achieved by decoding information stored on it by an arbitrarily long input tape. Later, John von Neumann applied Turing's thesis to the design of what became the first modern SIMD (single instruction multiple data path) computer architecture. Von Neumann's computational engine was realized as combinations of three elements: memory, processor and switch (MPS structures) which included electronic transistor and diode logic based Boolean digital logic elements (radix=2). In such prior art electronics components, indicated in FIG. 1, the hardware elements are supported by an instruction set architecture. This instruction set and its associated encode/decode hardware architecture, provide the operational codes (OP Code) and data flow instructions necessary for general purpose arithmetical, logical, and data flow control programming. Later, researchers extended the von Neumann architecture to parallel, or multiple instruction, multiple data path (MIMD) architectures. The advent of photonics led to massively parallel optical computer concepts which carried the Turing thesis further, but lacked the general purpose programmability of the older digital hardware. Thus, the virtually infinite signal/data bandwidth of the photonic (or optical) computer remains to date an under utilized advantage of photonics. Because of the lack of a general purpose programmable instruction set architecture, optical computers have not emerged as viable contenders for SIMD or MIMD digital computers--these hardware realizations (e.g. optical neural networks are relegated to special purpose processing tasks such as optical signal processing. That is, optical computers have served only as add-ons to electronic computers. For examples of optical special purpose computers, see U.S. Pat. No. 4,910,699 to Capps et al (1990), U.S. Pat. No. 4,948,959 to Houk et al (1990) and U.S. Pat. No. 4,387,989 to Pirich (1983). Inherent in the above optical systems is a lack of dynamic programmability and general purpose computability. Thus the linking of electronic computers with special purpose optical signal processors is the current state of the prior art. Also electronic computer systems require considerable electric power, often have limited data capacity and can be relatively slow and there is a need and market for a general purpose computer that exhibits marked improvement in all three of these categories. There has now been discovered a general purpose quantum computer that provides for the creation of an instruction set architecture and thus a dynamically programmable photonic universal Turing machine (UTM). SUMMARY OF THE INVENTION Broadly the present invention provides a method for general purpose quantum computing that includes the steps of: a) inputting a data signal through an encoder to encode the data signal with an instruction of OP Code data source and destination, b) transmitting the encoded signal by means of a light beam L1 to an input buffer, c) directing a reference light beam L2 so it interferes with the L1 beam in the buffer to form an interference pattern therein as a hologram, IPH. Further of such steps include: d) directing a read light beam L3 through the IPH and through a decoder which reads the instruction, e) the decoder presenting the instruction to ALU spin media which responds to the instruction by flipping spins in one or more sequences to resulting data patterns and reading or measuring such patterns to derive results therefrom. The invention includes a method for flipping spins between two energy levels or two level spin states. The invention also provides an apparatus for carrying out the above method. DEFINITIONS By "encoding" as used herein, is meant adding instructions to a data signal such as shown in FIGS. 3 and 4 hereof. By "decoding" as used herein, is meant reading the data signal and its instructions for further processing. By "quantum computing" as used herein, is meant the employment of the spin of subatomic particles to process data. By "system Hamiltonian" as used herein, is mean a series of energy levels relative to spin states in spin media, as illustrated in FIGS. 7 and 8 hereof and further discussed below. By "2 level spin states" as used herein, is meant flipping either nuclear ("n") spins (ie proton spins) or electronic ("e") spins (per FIGS. 7, 8, 10 & 11) between 2 energy levels to obtain digital data; also known as radix=2 (R=2) data. BRIEF DESCRIPTION OF THE DRAWINGS The invention will become more apparent from the following detailed specification and drawings in which: FIG. 1 is a block diagram, partially schematic view of a prior art electronic computer; FIG. 2 is a schematic perspective, partial block diagram of a quantum computer embodying the present invention; FIG. 3 is a schematic diagram of an instruction employed in a computer embodiment of the present invention; FIG. 4 is a schematic diagram of an operational code (OP Code) employed in the instruction of FIG. 3; FIG. 5 is an elevation schematic block diagram, partially in perspective, of a component of a quantum computer embodiment of the invention; FIG. 6 is a schematic elevation block diagram, in partial perspective, of a component of another quantum computer embodying the present invention; FIG. 7 is a schematic diagram of spin media employed in a computer embodying the present invention, FIG. 8 is a graph showing 2 energy levels or states of spin media employed in a quantum computer embodying the present invention, FIG. 9 is a schematic elevation view of layered destinations in spin media per the invention and FIGS. 10A & B and 11A & B are schematic elevation views which illlustrate "n" & "e" 2 level spin states respectively. DESCRIPTION OF THE PREFERRED EMBODIMENTS The state of the prior art as shown in FIG. 1 wherein a representative electronic general purpose computer 6 is linked to a special purpose optical processor 8, as shown. FIG. 2 illustrates the present invention as a schematic block diagram. Data is input to a computer using a variety of input devices including keyboard, digital or analog cameras, digital computer, bar code scanner or other data input device. In the case of image data, the data to be input to the UTM may be entered using a spatial light modulator, SLM. The specific data format is made compatible with the SLM through a custom interface. The input device has encoded commands using OP Codes from the UTM instruction set. An example of a UTM instruction set is given in FIGS. 3 and 4. FIG. 4 is illustrative of a subset of the UTM instruction set, since new commands can be created by the user (i.e. the device may be programmed locally). FIG. 4 thus represents the instruction set architecture concept. Again referring to FIG. 2, the SLM image data or signal is presented to an input buffer (e.g. a photorefractive crystal) 20 in which is formed an input holographic instruction page 22, which includes the optical, data source and destination memory locations per FIG. 3. The hologram is essentially the physical realization of the instruction. The input instructions (and data) can now be manipulated heuristically as in a digital computer. The instruction contains the OP Code (as shown in FIG. 3) and the source and destination locations for the data and the operation result. For example, an addition operation contains source and destination locations of the operands (e.g. 5+2=). In a dynamically programmable UTM, the user (or the program) may choose these on the fly, suggesting the possibility of using the present invention in, e.g. artificial intelligence applications such as autonomous IMINT (image intelligence) agents. The buffered instructions are sequentially read from the input buffer 20 by laser read beam L3. The instruction passes through a decoder 24. The decoder can be an optical correlator, e.g. another photorefractive crystal. Referring in more detail to FIG. 2, it can be seen that there are two inputs to the input buffer 20, one being the keyboard input 12 and the other being the image input 14, either of which passes through a custom interface encoder (16 or 18) to the input buffer 20. For example from input 12 and the custom interface encoders 16, a laser beam L1 transmits encoded data through an SLM 19 to the input buffer 20, per FIG. 2. The beam L1 carries information in a crossword puzzle-like pattern and meets or interferes with a reference laser beam L2 in the input buffer 20, which records such interference as an interference pattern or holographic grating 22, as shown in FIG. 2. Then a read-beam laser L3 is directed through the holographic grating 22 and through a decoder 24. Note that the encoder 16 (or 18) gives instruction per FIG. 3, to the incoming signal or data and the decoder 24 reads such instruction in decoding the data and passes same to a designated destination in the spin media. The spin media is programmed in layers 37 to perform certain instruction commands or responses such as "add" and "correllate" per FIGS. 3 and 4. Accordingly, the decoder 24 reads the IPH on read beam L3 and directs the instruction to the appropriate layer 37 of the spin media 34 per FIGS. 5 and 9 hereof. As indicated in FIG. 3, the encoded and decoded instruction have three components, the OP Code, the data sources (eg. S 1 and S 2 ) and destination locations or layers per FIG. 9. The so decoded data, (e.g. 5+2=) is passed to the "add" layer 37 of the spin media per FIG. 9, to calculate the operational result of such instruction. Thus S 1 can be data from a keyboard and S 2 , data from a camera or memory unit. The instruction gives the OP Code as, eg. "add" or "Xor", designates the source as, eg. from memory and gives the destination as, eg. the "add" or "Xor" layer 37 in the spin media per FIG. 9. The decoded instruction passed through the decoder 24 on read beam L3, passes to the destination layer of the data processor of the invention. Such processor has paramagnetic spin media in each layer with nuclear and electronic spins and a spin sensing apparatus and is known herein as the ALU (Arithmetic Logical Unit) quantum processor of the invention. The spin sensing apparatus can include microwave (MW) and radio frequency (RF) source and sensor units, waveguide and transmission lines for coupling the MW and RF energy to the spin sample and a magnetic material providing an AC modulated DC magnetic field of intensity B. Photonic perturbation of spin states results in spin inversion of a plurality of the spins. The radio frequency and microwave source/sensor units are shown in the schematic block diagrams of FIGS. 2 and 5 and further discussed below. Also FIG. 7 illustrates a schematic of ALU spin media having both electronic and nuclear spins. A schematic energy state programmed for a two-level (nuclear 1+> and 1-> state) system is shown in FIG. 8. The data is decoded and processed in the ALU spin media as spin state information. Transitions in spin state represent digital bit flips. For a further discussion on spin Hamiltonians see an Article entitled "Photon-Spin Interactions In Condensed Matter Photonic Systems: A Potential Foundation for Photonic Quantum Computing", in Photonic Component Engineering and Applications, SPIE 1996 Conf. Proc., A. R. Pirich, editor, SPIE PRESS by S. P. Hotaling, which Article is incorporated herein by reference. As shown, the ALU quantum computer element 25 has magnets 26 and 36 which establish a magnetic field B having flux lines 30 across the spin media 32 housed in container 34 per FIGS. 5 and 7. Per FIG. 5, the spin media is cooled to a relatively stable temperature by cryocooler 28. In addition to magnetic field B which operates on a z-axis, the microwave generator 36 transmits an MW field 38 across the spin media 32 on the y-axis per FIGS. 5 and 7. Also the RF generator 40 transmits RF waves through the spin media 32 on the x-axis, as shown in FIGS. 5 and 7. The x, y and z directions of the RF field, MW field and B field are shown schematically in FIG. 7. In the spin media 32 per FIG. 7 are protons known as nuclear spins 48 which are excited by RF transmission as shown or indicated in FIGS. 5 and 7. Also in the spin media are unpaired electrons or electronic spins 50, which are excited by microwaves, as shown or indicated in FIGS. 5 and 7. Also there are atoms or molecules with no net spin, i.e. neutral atoms or molecules 52 as shown in FIG. 7. As noted above, for 2 level spin states, one flips either "n" spins or "e" spins. That is, one operates either the RF source/sensor to excite and read the "n" spin flips up or down per FIG. 10 hereof or one operates the MW source/sensor to excite and read the "e" spin flips up or down, per FIG. 11 hereof, to obtain 2 level, binary or digital data. Now the read beam L3, as it comes through the decoder 24 and into a layer 37 of the spin media 32, carries a decoded beam of photons in a data pattern. When the photons of such beam strike the nuclear spins or the electronic spins, they invert according to the data pattern (decoded hologram or instruction) of such entering beam and the pattern of such spin inversions are read respectively by the MW sensor for the inversion pattern of the electronic spins or by the RF sensor for the inversion pattern of the nuclear spins, as indicated in FIGS. 5 7, 10 and 11. The above MW or RF sensors can read the resulting pattern of one sequence of spin flips or the resulting pattern of several or many sequences of spin flips which propagate until measurement and which represent one or more computational steps. The spin media in each layer, can be programmed to respond in different ways or functions to the incoming data pattern in a logic gate type fashion, e.g. to perform Boolean logic functions according to a desired Hamiltonian. That is, there are two types of Hamiltonians--those which can be controlled by external field perturbations (e.g. through photon-spin interactions) and those which can be programmed to run independent of external field interactions. For the former case, a spin flip interaction (for example--the result of a quantum computation) can be "clocked" by external photonic perturbation, eg. by an L4 laser beam directed into the spin media 34 per FIG. 5, which instructs such media when to take a measurement and output a data signal and when not to. That is, the spin flips in the spin media are running per the received instructions of the decoded beam L3 but a data signal therefrom is output only when the L4 beam so directs the spin media. Such L4 beam can thus have, eg. on-off instructions incorporated therein. The result (e.g. 5+2=7) can be measured immediately upon completion of the computation (by, eg. RF, MW or optical sensor means) and then can be used as input ("prepared") to another quantum element or gate. One can envision a series of such quantum gates to form a quantum chain. For the latter case (purely time-dependent Hamiltonian interaction),which is more common and a preferred embodiment of the invention, a quantum chain is presented with data at the input and as time evolves, the results of quantum calculations propagate in the spin media until measurement occurs, i.e. the resulting pattern is read by one of the above sensors in the absence of such L4 beam. The decoded beam (of photons) L3 can come in at any angle relative to the above noted x, y and z directions into the spin media, eg. of FIG. 7, as desired within the scope of the invention. Sensing of the inversions of nuclear or electronic spins (by the MW or RF sensor) provides a relatively high speed stream of (2 level spin state) data that can be optically read as digital data for arthmetic and logical operations. When either of the MW and RF sources/sensors are operating, each can output a signal to the I/O device. For further information on RF and MW source/sensor units, see "Electrons Spin Resonance" by C. Poole and H. A. Farach, AIP Press 1994, which Article is incorporated herein by reference. In other embodiments of the invention the MW and RF source/sensor units can be omitted and the above spin inversions read optically, e.g. by passing laser beam L5 through the spin media 32 to beam detector 58, per FIG. 6, which optically detects the above spin inversions in a data pattern and transmits same to an optical multi-channel analyzer (OMA) 60, which detects such spin flips by an optical frequency shift using optically detected magnetic resonance (ODMR) and outputs optical digital data therefrom for arthmetic and logical operations. That is, the intensity of the B field is swept slowly and causes the spins to line up directionally, e.g. per FIG. 7. Then the photons arrive in a layer of the spin media as decoded data (in a pattern) on laser beam L3, which flip a plurality of the "n" or "e" spins, one or more times (in one or more sequences) from, e.g. upwardly to downwardly (per FIGS. 10 or 11), in a pattern according to the pattern of the decoded instructions on the L3 beam. These spin flips are sensed by the MW sensor or the RF sensor or by the OMA, as noted above and processed as digital data and output, e.g. for arthmetic and logical operations from I/O device 59, as indicated in FIGS. 5 and 6. Per the invention, the spin media can be a crystal eg. of, ferro electric or photo refractive material, a liquid crystal and other similar paramagnetic crystals or such spin media can be located in a concentrated gas of, eg. cesium or rare earth ions. Also, in another embodiment of the invention, laser and photorefractive units may be replaced by direct write non-coherent data inputs such as white light, IR or UV light. The computational machine of the present invention extends the Turing thesis to enable dynamic, general purpose quantum computing. In the present invention, this is taken to mean that the data are physically realized as quantum-mechanical spin states of nuclear and electronic species, rather than bunches of electrons (per the prior art) which employs voltages corresponding to Boolean 1 and 0 states. In moving from prior art electronic (digital) computers to spin-based quantum computers, one can considerably increase the speed and amount of information processed whether employing R=2 or R>2 spin state media per the present invention. Also the quantum-mechanical spin-based computers of the invention have the potential for multiple valued logic (radix, or bases higher than 2) per a companion patent application filed herewith. This results in superior information content and signal/data bandwidth for the quantum-mechanical UTM. The present quantum-mechanical (digital) embodiment of the invention also exceeds the state of the art which is achieved by creation of an instruction set architecture (essentially the dynamic hardware/software system intelligence) which is capable of operating as a multidimensional alternating UTM. The spin media of the invention for Radix=2, can be crystals such as NaCl, InP, Bi 12 SiO 20 , GaAs, LiNbO 3 and other electro-optic paramagnetic crystals (eg. GaInP) as well as other materials including polymers (eg. DCPVA) or spin glasses (eg. Fe doped silicate glasses) and other optically active, spin-rich materials. And to increase the strength of the spin state signal, one can add dopants, eg. Er, Mn, Cr and Fe to one or more of the above materials. Thus the invention provides a universal Turing machine based upon photonic perturbation of quantum-mechanical nuclear and electronic spin states in condensed matter systems. The general purpose quantum computer of the invention has applicability across the entire spectrum of information technology including information security cryptography, eg. for the protection of bank computer systems, cyrpto-analysis, probability calculations and many other uses including where ever conventional electronic computers are now used.

Method and apparatus are provided for a general purpose photonic computer. A data signal is input through an encoder to encode such signal with an instruction. The encoded signal is transmitted by means of a laser beam to an input buffer where it interferes with a reference beam so as to form an interference pattern therein as a hologram, IPH. A read beam is directed through the IPH and through a decoder which reads the instruction as having, e.g. an OP Code, data source and destination. The decoded instruction is forwarded on the read beam to ALU spin media which respond to the instruction by flipping spins between two energy levels, in one or more sequences of data patterns which are read or measured by one or more sensors. Such sensors can be RF, microwave or optical sensors, which sensors output Radix=2 or digital data signals for, e.g. storage, display or further processing as desired. Thus the present invention teaches a novel exploitation of photon-induced, quantum-mechanical spin transitions in spin media. The input signal can be from a keyboard, camera, bar code or other input source.

BACKGROUND OF THE INVENTION This application is the U.S. National Phase of PCT Application Number PCT/GB03/00373, filed on 29 Jan. 2003, which claims priority to Great Britain Application Number 0202142.6, filed 30 Jan. 2002. This invention relates to a watercraft which may be used for sailing using wind power, but which can maintain a level trim when mechanically propelled at high speeds. 1. Field of Invention Sailing craft can be provided with a displacement mono-hull with a transverse cross-section which tapers downwardly on each side to its keel line, and which increases in cross-section from the bow to a fullest transverse section, and decreases in cross section from the fullest transverse section to the after end. Such a mono-hull shape is suitable for sailing because of its streamlined longitudinal shape when upright and when heeled over. However, displacement mono-hulled sailing craft as described above are not suitable to be mechanically propelled at high speeds. When mechanical propulsion means, for example an outboard motor or a screw, provide high levels of forward thrust to the after end of the hull, the bow is forced out of the water and the aft sinks lower into the water. This slows the craft because its forward facing profile is increased, which results in a greater resistance against the water. The more power which is provided to the after end of the hull, the greater the bow lift and the water resistance. As a result the maximum speed which can be reached is fixed, regardless of the size of the engine. The object of the present invention is to overcome some of these problems and provide a watercraft with a displacement hull which may be used for sailing and be mechanically propelled at high speeds. 2. Description of the Related Art A previous attempt to provide a watercraft which may be used for sailing and be mechanically propelled at high speeds is shown in shown in GB2150890 in the name of LANCER YACHT CORPORATION. GB2150890 discloses a combination sailboat-powerboat hull in the form of a round-bottom, ballasted displacement hull, which is provided with generally horizontal foils which extend along the static water line on both sides of the hull, the forward ends of the foils being faired into the hillsides approximately amidships from where the foils extend rearwardly towards the quarters, and the foils extending out from the hullsides a distance less than the thickness of the boundary layer at sailing hull speed, the undersurface area of the foils being such as to enable the hull to plane when driven under auxiliary power. It has been found that the watercraft disclosed in GB2150890 does not work as claimed. The “foils” described therein are planing surfaces which project from the hull and disrupt its streamlined shape. As a result the “foils” create drag which is detrimental to the performance of the craft when sailed and in particular when heeled over. In order to minimise this drag, the “foils” are narrow in shape and do not extend through the boundary layer into the laminar zone. As a result the lifting force provided by the “foils” as they plane over the water when the craft is powered by a motor is very small and does not prevent the aft of the craft from sinking lower into the water. Therefore, in an attempt to minimise the disruptive effect of the “foils” when sailing, they are made so small as to render the invention redundant. The present invention is intended to provide a novel approach. BRIEF SUMMARY OF THE INVENTION Therefore, according to the present invention a wind driven sailing craft with a hull of the displacement type with a keel or keels, is provided with hydrofoil means adapted to lift the stern of the craft when the craft is propelled forwards in use by power propulsion means acting at the stern of the hull. The hydrofoil means can comprise a flat hydrofoil element, which is attached in a transverse arrangement by struts to the bottom of the after end of the hull of the sailing craft. When the sailing craft is propelled forwards in use by power propulsion means acting at the stern of the hull, the angle of the hydrofoil is set to provide the optimum level of lift to the aft to maintain the optimum trim level for the particular speed of the craft. As the speed of the craft changes the angle of the hydrofoil element can be adjusted, either manually or automatically, to provide the optimum level of lift to the aft to maintain an optimum trim level at any speed. Preferably the sailing craft is mono-hulled with a transverse cross-section which tapers downwardly to its keel line, and which increases in cross-section from the bow to a fullest transverse section, and decreases in cross section from the fullest transverse section to the after end. The keel line of the hull tapers downwardly from the bow and the stern to a base line at the fullest transverse section. The sailing craft can be provided with a drop, or a swing, keel, which is lowered into position to provide ballast when the craft is sailing, and is raised to reduce drag when the craft is propelled forwards by power propulsion means. Further, the craft can also be provided with internal water ballast tanks which can be filled with water to provide ballast when sailing, and emptied to reduce the displacement when the craft is propelled forwards by power propulsion means. When the craft is being powered by its sails the hydrofoil is set level to the water flow under the after end of the hull so zero lift and minimum drag are provided and the hull operates as a normal sailing hull. It has been found that the hydrofoil provides stability to the hull when the craft is being sailed and acts as a damper in rough conditions, which are additional benefits. In one construction the hydrofoil is disposed approximately level with the base line of the hull. However, in another construction the hydrofoil is disposed approximately level with the base line of the drop keel. It has been found that with either of these arrangements when the craft is grounded or removed from the water it can be supported in an upright position by the lowest point of the hull or the keel and the hydrofoil, like a tripod, which is an additional benefit. Preferably, the hydrofoil element is attached to the bottom of the hull by two struts. The hydrofoil element can be substantially rectangular in shape, with the shorter sides thereof disposed substantially parallel to the direction of the hull. Further, the hydrofoil element can have a streamlined cross-section with an elongated tear-drop shape, which passes through the water with the least drag. The hydrofoil element can be adapted to rotate on a transverse axis to provide variable lift to the stern of the sailing craft. In one construction the struts are provided with rudder elements adapted to steer the craft. The rudder elements can be fixed aft of the struts, can be provided as part of the struts, or the struts can be the rudder elements. With this arrangement a traditional rudder is not required for the craft, which further reduces drag. The power propulsion means can be an inboard engine, preferably provided with a screw acting at the stern of the hull. The screw can have a known type of blades which can be rotated to be parallel with the direction of the hull to reduce drag when sailing. In a preferred construction the hydrofoil element can be rotated from a zero lift angle level with the water flow under the aft end of the hull, to a lift angle of approximately −5 to −8 degrees. The upper hull of the sailing craft can be shaped with a spray rail feature to shield the operators from wash produced at high speeds. The system can be used on any sailing craft, but in a preferred construction the invention is applied to a 13 meter ocean-going yacht, with about 6 berths. The invention also includes a hydrofoil element for use with a wind driven sailing craft with a hull of the displacement type with a keel or keels, which is provided with hydrofoil means adapted to lift the stern of the craft when the craft is propelled forwards in use by power propulsion means acting at the stern of the hull. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be performed in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawings in which: FIG. 1 is a perspective view of a boat hull according to the present invention; FIG. 2 is a perspective view of another boat hull according to the present invention; FIG. 3 a is a diagrammatic front view of the cross sectional contours of the hull shown in both FIGS. 1 and 2 ; FIG. 3 b is a diagrammatic side view of the hull shown in FIG. 3 a with the cross-sectional lines; FIG. 4 is a side view of a yacht according to the present invention, arranged for sail operation; FIG. 5 is a side view of the yacht shown in FIG. 4 arranged for motorised operation; FIG. 6 a is a diagrammatic front view of the cross sectional contours of the hull shown in both FIGS. 4 and 5 ; and, FIG. 6 b is a diagrammatic side view of the hull shown in FIG. 6 a with the cross sectional lines. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 shows a displacement boat hull 1 which is shaped for sailing and is approximately 13 meters in length. FIGS. 3 a and 3 b show the cross-sectional contours of the hull 1 . The hull 1 has a broad beam to provide sufficient righting moment to support the sails and provide an adequate lever arm for internal water ballast. In other respects the hull 1 is a shaped for high-speed sailing (approximately 10 knots). As shown in FIG. 1 the hull 1 is provided with a drop keel 2 with a ballast bulb 3 , and a hydrofoil element 4 . The hydrofoil element 4 comprises two struts 5 and an interconnecting horizontal wing 6 . The wing 6 is substantially rectangular in shape with the shorter sides thereof disposed substantially parallel to the direction of the hull 1 . The hydrofoil element is mounted adjacent to the aft 7 of the hull 1 . In FIG. 2 displacement boat hull 8 is identical to the hull 1 shown in FIG. 1 , except for recess 9 provided on the lower surface. Recess 9 is dimensioned to receive the upper section of the ballast bulb 11 when the keel 10 is raised. Further, struts 12 have been provided with rudder elements 13 to steer the craft. FIGS. 4 and 5 show a displacement mono-hulled 13 meter sailing yacht 14 . FIGS. 6 a and 6 b show the cross-sectional contours of the hull 15 . This type of yacht is known so further details will not be described here. The yacht 14 has a hull 15 shaped for sailing, a sailing rig 16 and a motorised screw 17 . The hull 15 is also provided with a spray rail ledge 18 to protect the operators of the craft from wash at high speeds. (The shape of the spray rail 18 can be better seen in FIGS. 6 a and 6 b ). The yacht 14 is provided with a hydrofoil element 19 comprising two struts 20 (only one shown) and an interconnecting horizontal wing (not shown). The hydrofoil element is identical to that shown in FIG. 2 with rudder elements 21 provided on the struts 20 , and it is attached to the bottom of the hull 15 , adjacent to the aft 22 of the yacht 14 . The yacht 14 is also provided with a drop keel 23 with a ballast bulb 24 . The hull 15 also features a recess (not shown) into which the upper section of the ballast bulb 24 can fit when the drop keel 23 is raised. As shown in FIG. 4 the yacht 14 is set for sail operation with the sailing rig 16 arranged to provide propulsion. The wing (not shown) of the hydrofoil element 19 is set level to the water flow under the after end 22 of the hull so zero lift and minimum drag are provided and the hull 15 can operate as normal. As shown in FIG. 5 the yacht is set for powered operation with the sailing rig 16 lowered. The drop keel 23 has been raised and the upper section of the ballast bulb 24 has been received by the recess (not shown) in the bottom of the hull 15 . When the screw 17 pushes the yacht through the water at high speeds the wing (not shown) of the hydrofoil element 19 is set at a negative angle and the higher water pressure on the underside of the wing creates lift and holds the yacht 14 at a level trim. As the speed of the yacht changes the wing is adjusted automatically to provide the optimum level of lift to the aft to maintain an optimum trim level. It will be appreciated that the speed of the yacht can be changed by engine speed as well as sea and weather conditions and any angle of turn, so the wing can be set to respond to these changes to maintain a level trim. It will also be appreciated that the correct wing angles required at high speeds will depend on the size, displacement and engine capacity of the craft with which is it used. The yacht 14 can be provided with internal water ballast tanks on each side of the hull 15 approximately amidships, in order to provided extra righting moment during sailing. The tanks can be filled automatically when the yacht 14 is in sailing mode, as shown in FIG. 4 , and then emptied to reduce weight and displacement when the yacht 14 is in motor mode, as shown in FIG. 5 . The spray rail 18 protects the occupants of the yacht 14 from water spray created by the high speed of the yacht 14 . Although the above describes the invention as applied to a displacement mono-hulled sailing craft, it will be appreciated that the invention can also be applied to a multi-hulled sailing craft. Further, a hydrofoil wing can be attached to the underside of the aft of a sailing craft in any appropriate manner, for example by one or three struts. In addition, if desired the hydrofoiling effect can be achieved by a number of hydrofoil wings attached to the underside of the hull in any appropriate manner.

A wind driven sailing craft is disclosed with a hydrofoil element which provides variable lift to the stern of the craft to maintain a level trim when the craft is operated under power propulsion. The hydrofoil element includes a hydrofoil wing which rotates on a transverse axis to provide the desired lift.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application No. U.S. Ser. No. 14/946,203, filed Nov. 19, 2015, which is a continuation of U.S. patent application No. U.S. Ser. No. 14/635,573, filed Mar. 2, 2015, now U.S. Pat. No. 9,233,211, which is a continuation of U.S. patent application Ser. No. 13/919,251, filed Jun. 17, 2013, now U.S. Pat. No. 9,011,391, which is a divisional of U.S. patent application Ser. No. 13/040,198, filed Mar. 3, 2011, now U.S. Pat. No. 8,512,297, which is a continuation of U.S. patent application Ser. No. 11/483,546, filed Jul. 11, 2006, now U.S. Pat. No. 7,918,833, which is a continuation of U.S. patent application Ser. No. 10/790,225, filed Mar. 2, 2004, which claims priority to GB 0304822.0 filed Mar. 3, 2003, the entire contents of which are incorporated herein by reference. BACKGROUND [0002] The present invention relates to pen-type injectors, that is, to injectors of the kind that provide for administration by injection of medicinal products from a multidose cartridge. In particular, the present invention relates to such injectors where a user may set the dose. [0003] Such injectors have application where regular injection by persons without formal medical training occurs. This is increasingly common amongst those having diabetes where self-treatment enables such persons to conduct effective management of their diabetes. [0004] These circumstances set a number of requirements for pen-type injectors of this kind. The injector must be robust in construction, yet easy to use both in terms of the manipulation of the parts and understanding by a user of its operation. In the case of those with diabetes, many users will be physically infirm and may also have impaired vision. Where the injector is to be disposable rather than reusable, the injector should be cheap to manufacture and easy to dispose of (preferably being suitable for recycling). SUMMARY [0005] It is an advantage of the present invention that an improved pen-type injector is provided. [0006] According to a first aspect of the present invention, a pen-type injector comprises a housing; a piston rod adapted to operate through housing; a dose dial sleeve located between the housing and the piston rod, the dose dial sleeve having a helical thread of first lead; a drive sleeve located between the dose dial sleeve and the piston rod, the drive sleeve having a helical groove of second lead; characterized in that the first lead of the helical thread and the second lead of the helical groove are the same. [0012] Preferably, the piston rod has a first threaded portion at a first end and a second threaded portion at a second end; an insert or radially inwardly extending flange is located in the housing and through which the first threaded portion of the piston rod may rotate; the dose dial sleeve being rotatable with respect to the housing and the insert; the drive sleeve being releasably connected to the dose dial sleeve and connected to the piston rod for rotation with respect thereto along the second threaded portion of the piston rod; a button is located on the dose dial sleeve and rotatable with respect to the does dial sleeve; and clutch means are provided which upon depression of the button permit rotation between the dose dial sleeve and the drive sleeve. [0018] Preferably, the injector further comprises a nut which is rotatable with respect to the drive sleeve and axially displaceable but not rotatable with respect to the housing. [0019] More preferably, the drive sleeve is provided at a first end with first and second flanges with an intermediate thread between the first and second flanges, the nut being disposed between the first and second flanges and keyed to the housing by spline means. Additionally, a first radial stop may be provided on a second face of the nut and a second radial stop may be provided on a first face of the second flange. [0020] Preferably, the first thread of the piston rod is oppositely disposed to the second thread of the piston rod. [0021] Preferably, a second end of the clutch is provided with a plurality of dog teeth adapted to engage with a second end of the dose dial sleeve. [0022] Preferably, the pen-type injector further includes clicker means disposed between the clutch means and spline means provided on the housing. [0023] More preferably, the clicker means comprises a sleeve provided at a first end with a helically extending arm, a free end of the arm having a toothed member, and at a second end with a plurality of circumferentially directed saw teeth adapted to engage a corresponding plurality of circumferentially saw teeth provided on the clutch means. [0024] Alternatively, the clicker means comprises a sleeve provided at a first end with at least one helically extending arm and at least one spring member, a free end of the arm having a toothed member, and at a second end with a plurality of circumferentially directed saw teeth adapted to engage a corresponding plurality of circumferentially directed saw teeth provided on the clutch means. [0025] Preferably, the main housing is provided with a plurality of maximum dose stops adapted to be abutted by a radial stop provided on the dose dial sleeve. More preferably, at least one of the maximum dose stops comprises a radial stop located between a helical rib and spline means provided at a second end of the housing. Alternatively, at least one of the maximum dose stops comprises a part of a raised window portion provided at a second end of the housing. [0026] Preferably, the dose dial sleeve is provided with a plurality of radially extending members adapted to abut a corresponding plurality of radial stops provided at a second end of the housing. BRIEF DESCRIPTION OF THE FIGURES [0027] The invention will now be described with reference to the accompanying drawings in which: [0028] FIG. 1 shows a sectional view of a pen-type injector in accordance with the present invention in a first, cartridge full, position; [0029] FIG. 2 shows a sectional view of the pen-type injector of FIG. 1 in a second, maximum first dose dialed, position; [0030] FIG. 3 shows a sectional view of the pen-type injector of FIG. 1 in a third, first maximum first dose dispensed, position; [0031] FIG. 4 shows a sectional view of the pen-type injector of FIG. 1 in a fourth, final dose dialed, position; [0032] FIG. 5 shows a sectional view of the pen-type injector of FIG. 1 in a fifth, final dose dispensed, position; [0033] FIG. 6 shows a cut-away view of a first detail of the pen-type injector of FIG. 1 ; [0034] FIG. 7 shows a partially cut-away view of a second detail of the pen-type injector of FIG. 1 ; [0035] FIG. 8 shows a partially cut-away view of a third detail of the pen-type injector of FIG. 1 ; [0036] FIG. 9 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dialing up of a dose; [0037] FIG. 10 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dialing down of a dose; [0038] FIG. 11 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dispensing of a dose; [0039] FIG. 12 shows a partially cut-away view of the pen-type injector of FIG. 1 in the second, maximum first dose dialed, position; [0040] FIG. 13 shows a partially cut-away view of the pen-type injector of FIG. 1 in the fourth, final dose dialed, position; [0041] FIG. 14 shows a partially cut-away view of the pen-type injector of FIG. 1 in one of the first, third or fifth positions; [0042] FIG. 15 shows a cut-away view of a first part of a main housing of the pen-type injector of FIG. 1 ; and [0043] FIG. 16 shows a cut-away view of a second part of the main housing of the pen-type injector of FIG. 1 . DETAILED DESCRIPTION [0044] Referring first to FIGS. 1 to 5 , there may be seen a pen-type injector in accordance with the present invention in a number of positions. [0045] The pen-type injector comprises a housing having a first cartridge retaining part 2 , and second main housing part 4 . A first end of the cartridge retaining means 2 and a second end of the main housing 4 are secured together by retaining features 6 . In the illustrated embodiment, the cartridge retaining means 2 is secured within the second end of the main housing 4 . [0046] A cartridge 8 from which a number of doses of medicinal product may be dispensed is provided in the cartridge retaining part 2 . A piston 10 is retained in a first end of the cartridge 8 . [0047] A removable cap 12 is releasably retained over a second end of the cartridge retaining part 2 . In use the removable cap 12 can be replaced by a user with a suitable needle unit (not shown). A replaceable cap 14 is used to cover the cartridge retaining part 2 extending from the main housing 4 . Preferably, the outer dimensions of the replaceable cap 14 are similar or identical to the outer dimensions of the main housing 4 to provide the impression of a unitary whole when the replaceable cap 14 is in position covering the cartridge retaining part 2 . [0048] In the illustrated embodiment, an insert 16 is provided at a first end of the main housing 4 . The insert 16 is secured against rotational or longitudinal motion. The insert 16 is provided with a threaded circular opening 18 extending therethrough. Alternatively, the insert may be formed integrally with the main housing 4 the form of a radially inwardly directed flange having an internal thread. [0049] A first thread 19 extends from a first end of a piston rod 20 . The piston rod 20 is of generally circular section. The first end of the piston rod 20 extends through the threaded opening 18 in the insert 16 . A pressure foot 22 is located at the first end of the piston rod 20 . The pressure foot 22 is disposed to abut a second end of the cartridge piston 10 . A second thread 24 extends from a second end of the piston rod 20 . In the illustrated embodiment the second thread 24 comprises a series of part threads rather than a complete thread. The illustrated embodiment is easier to manufacture and helps reduce the overall force required for a user to cause medicinal product to be dispensed. [0050] The first thread 19 and the second thread 24 are oppositely disposed. The second end of the piston rod 20 is provided with a receiving recess 26 . [0051] A drive sleeve 30 extends about the piston rod 20 . The drive sleeve 30 is generally cylindrical. The drive sleeve 30 is provided at a first end with a first radially extending flange 32 . A second radially extending flange 34 is provided spaced a distance along the drive sleeve 30 from the first flange 32 . An intermediate thread 36 is provided on an outer part of the drive sleeve 30 extending between the first flange 32 and the second flange 34 . A helical groove 38 extends along the internal surface of the drive sleeve 30 . The second thread 24 of the piston rod 20 is adapted to work within the helical groove 38 . [0052] A first end of the first flange 32 is adapted to conform to a second side of the insert 16 . [0053] A nut 40 is located between the drive sleeve 30 and the main housing 2 , disposed between the first flange 32 and the second flange 34 . In the illustrated embodiment the nut 40 is a half-nut. This assists in the assembly of the injector. The nut 40 has an internal thread matching the intermediate thread 36 . The outer surface of the nut 40 and an internal surface of the main housing 4 are keyed together by splines 42 (see FIGS. 10, 11, 15 and 16 ) to prevent relative rotation between the nut 40 and the main housing 4 , while allowing relative longitudinal movement therebetween. [0054] A shoulder 37 is formed between a second end of the drive sleeve 30 and an extension 38 provided at the second end of the drive sleeve 30 . The extension 38 has reduced inner and outer diameters in comparison to the remainder of the drive sleeve 30 . A second end of the extension 38 is provided with a radially outwardly directed flange 39 . [0055] A clicker 50 and a clutch 60 are disposed about the drive sleeve 30 , between the drive sleeve 30 and a dose dial sleeve 70 (to be described below). [0056] The clicker 50 is located adjacent the second flange 34 of the drive sleeve 30 . The clicker 50 is generally cylindrical and is provided at a first end with a flexible helically extending arm 52 (shown most clearly in FIG. 6 ). A free end of the arm 52 is provided with a radially directed toothed member 54 . A second end of the clicker 50 is provided with a series of circumferentially directed saw teeth 56 (of FIG. 7 ). Each saw tooth comprises a longitudinally directed surface and an inclined surface. [0057] In an alternative embodiment (not shown) the clicker means further includes at least one spring member. The at least one spring member assists in the resetting of the clutch means 60 following dispense. [0058] The clutch means 60 is located adjacent the second end of the drive sleeve 30 . The clutch means 60 is generally cylindrical and is provided at a first end with a series of circumferentially directed saw teeth 66 (see FIG. 7 ). Each saw tooth comprises a longitudinally directed surface and an inclined surface. Towards the second end 64 of the clutch means 60 there is located a radially inwardly directed flange 62 . The flange 62 of the clutch means 60 is disposed between the shoulder 37 of the drive sleeve 30 and the radially outwardly directed flange 39 of the extension 38 . The second end of the clutch means 60 is provided with a plurality of dog teeth 65 ( FIG. 8 ). The clutch 60 is keyed to the drive sleeve 30 by way of splines (not shown) to prevent relative rotation between the clutch 60 and the drive sleeve 30 . [0059] In the illustrated embodiment, the clicker 50 and the clutch 60 each extend approximately half the length of the drive sleeve 30 . However, it will be understood that other arrangements regarding the relative lengths of these parts are possible. [0060] The clicker 50 and the clutch means 60 are normally engaged, that is as shown in FIG. 7 . [0061] A dose dial sleeve 70 is provided outside of the clicker 50 and clutch means 60 and radially inward of the main housing 4 . A helical groove 74 is provided about an outer surface of the dose dial sleeve 70 . [0062] The main housing 4 is provided with a window 44 through which a part of the outer surface of the dose dial sleeve may be seen. The main housing 4 is further provided with a helical rib 46 , adapted to be seated in the helical groove 74 on the outer surface of the dose dial sleeve 70 . The helical rib 46 extends for a single sweep of the inner surface of the main housing 4 . A first stop 100 is provided between the splines 42 and the helical rib 46 ( FIG. 15 ). A second stop 102 , disposed at an angle of 180° to the first stop 100 is formed by a frame surrounding the window 44 in the main housing 4 ( FIG. 16 ). [0063] Conveniently, a visual indication of the dose that may be dialed, for example reference numerals (not shown). is provided on the outer surface of the dose dial sleeve 70 . The Window 44 conveniently only allows to be viewed a visual indication of the dose currently dialed. [0064] A second end of the dose dial sleeve 70 is provided with an inwardly directed flange in the form of number of radially extending members 75 . A dose dial grip 76 is disposed about an outer surface of the second end of the dose dial sleeve 70 . An outer diameter of the dose dial grip 76 preferably corresponds to the outer diameter of the main housing 4 . The dose dial grip 76 is secured to the dose dial sleeve 70 to prevent relative movement therebetween. The dose dial grip 76 is provided with a central opening 78 . An annular recess 80 located in the second end of the dose dial grip 76 extends around the opening 78 . [0065] A button 82 of generally ‘T’ section is provided at a second end of the pen-type injector. A stem 84 of the button 82 may extend through the opening 78 in the dose dial grip 76 , through the inner diameter of the extension 38 of the drive sleeve 30 and into the receiving recess 26 of the piston rod 20 . The stem 84 is retained for limited axial movement in the drive sleeve 30 and against rotation with respect thereto. A head 85 of the button 82 is generally circular. A skirt 86 depends from a periphery of the head 85 . The skirt 86 is adapted to be seated in the annular recess 80 of the dose dial grip 76 . [0066] Operation of the pen-type injector in accordance with the present invention will now be described. In FIGS. 9, 10 and 11 arrows A, B. C, D, E, F and G represent the respective movements of the button 82 , the dose dial grip 76 , the dose dial sleeve 70 , the drive sleeve 30 , the clutch means 60 , the clicker 50 and the nut 40 . [0067] To dial a dose ( FIG. 9 ) a user rotates the dose dial grip 76 (arrow A). With the clicker 50 and clutch means 60 engaged, the drive sleeve 30 , the clicker 50 , the clutch means 60 and the dose dial sleeve 70 rotate with the dose dial grip 76 . [0068] Audible and tactile feedback of the dose being dialed is provided by the clicker 50 and the clutch means 60 . Torque is transmitted through the saw teeth 56 , 66 between the clicker 50 and the clutch means 60 . The flexible arm 52 deforms and drags the toothed member 54 over the splines 42 to produce a click. Preferably, the splines 42 are dispose such that each click corresponds to a unit dose. [0069] The helical groove 74 on the dose dial sleeve 70 and the helical groove 38 in the drive sleeve 30 have the same lead. This allows the dose dial sleeve 70 (arrow C) to extend from the main housing 4 and the drive sleeve 30 (arrow D) to climb the piston rod 20 at the same rate. At the limit of travel, a radial stop 104 on the dose dial sleeve 70 engages either the first stop 100 or the second stop 102 provided on the main housing 4 to prevent further movement. Rotation of the piston rod 20 is prevented due to the opposing directions of the overhauled and driven threads on the piston rod 20 . [0070] The nut 40 , keyed to the main housing 4 , is advanced along the intermediate thread 36 by the rotation of the drive sleeve 30 (arrow D). When the final dose dispensed position ( FIGS. 4, 5 and 13 ) is reached, a radial stop 106 formed on a second surface of the nut 40 abuts a radial stop 108 on a first surface of the second flange 34 of the drive sleeve 30 preventing both the nut 40 and the drive sleeve 30 from rotating further. [0071] In an alternative embodiment (not shown) a first surface of the nut 40 is provided with a radial stop for abutment with a radial stop provided on a second surface of the first flange 32 . This aids location of the nut 40 at the cartridge full position during assembly of the pen-type injector. [0072] Should a user inadvertently dial beyond the desired dosage, the pen-type injector allows the dosage to be dialed down without dispense of medicinal product from the cartridge ( FIG. 10 ). The dose dial grip 76 is counter rotated. This causes the system to act in reverse. The flexible arm 52 now acts as a ratchet preventing the clicker from rotating. The torque transmitted through the clutch means 60 causes the saw teeth 56 , 66 to ride over one another to create the clicks corresponding to dialed dose reduction. Preferably the saw teeth 56 , 66 are so disposed that the circumferential extent of each saw tooth corresponds to a unit dose. [0073] When the desired dose has been dialed, the user may then dispense this dose by depressing the button 82 ( FIG. 11 ). This displaces the clutch means 60 axially with respect to the dose dial sleeve 70 causing the dog teeth 65 to disengage. However the clutch means 60 remains keyed in rotation to the drive sleeve 30 . The dose dial sleeve 70 and associated dose dial grip 76 are now free to rotate (guided by the helical rib 46 located in helical groove 74 ). [0074] The axial movement deforms the flexible arm 52 of the clicker 50 to ensure the saw teeth 56 , 66 cannot be overhauled during dispense. This prevents the drive sleeve 30 from rotating with respect to the main housing 4 though it is still free to move axially with respect thereto. This deformation is subsequently used to urge the clicker 50 , and the clutch 60 , back along the drive sleeve 30 to restore the connection between the clutch 60 and the dose dial sleeve 70 when pressure is removed from the button 82 . [0075] The longitudinal axial movement of the drive sleeve 30 causes the piston rod 20 to rotate though the opening 18 in the insert 16 , thereby to advance the piston 10 in the cartridge 8 . Once the dialed dose has been dispensed, the dose dial sleeve 70 is prevented from further rotation by contact of a plurality of members 110 ( FIG. 14 ) extending from the dose dial grip 76 with a corresponding plurality of stops 112 formed in the main housing 4 ( FIGS. 15 and 16 ). In the illustrated embodiment, the members 110 extend axially from the dose dial grip 76 and have an inclined end surface. The zero dose position is determined by the abutment of one of the axially extending edges of the members 110 with a corresponding stop 112 .

The present invention relates to injectors, such as pen-type injectors, that provide for administration of medicinal products from a multidose-cartridge and permit a user to set the delivery dose. The injector may include a housing, a piston rod adapted to operate through the housing, a dose dial sleeve located between the housing and the piston rod, and a drive sleeve located between the dose dial sleeve and the piston rod. The dose dial sleeve may have a helical thread of first lead and the drive sleeve may have a helical groove of second lead. The first lead of the helical thread and the second lead of the helical groove may be the same.

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 2003-91016, filed on Dec. 13, 2003, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND 1. Field of the Invention The present invention relates to a driver agent device and a operation method thereof and, more specifically, to a driver agent device for supporting remote device driver development environment in an embedded system and an operation method thereof, in which a developer can process various services such as retrieving hardware information needed for device development, authenticating resources and applying a device driver to a target system, without expert knowledge on an embedded system in a Linux-operated embedded system. 2. Discussion of Related Art Recently, an embedded system that had been used in a restricted field such as industry and military has widely used in medicals and consumer electronics. Therefore, much attention is paid to the rapid development of the embedded system by embedded system development industries to acquire a more market share. A development process of the embedded system can be divided into a hardware development process and a software development process. The device driver development, which may be positioned between these two development processes, is widely known as a time-consuming process as a bottleneck point of the embedded system development process. In particular, the device driver development environment for the embedded system having inevitably complicated remote development causes much more difficulty in the device driver development. In addition, there are various and unique functions of the embedded systems for each individual embedded system compared with a general computer system so that the used devices are also diversified and unique. Therefore, the costs spent for developing device drivers for these devices are inevitably high. In addition, conventional technologies for supporting the device driver development have focused on the Window-based device driver development for a desktop system. In the conventional technologies, simple hardware authentication processing, device driver installation, and test processing are provided to support the development of the device driver operating in a given operating system in a negative development environment where a host system and a target system are not separated. FIG. 1 is a schematic block diagram illustrating a device driver development environment using a device driver development support program according to the prior art. As shown in FIG. 1 , in the prior art, a device driver development support program 3 supporting a device driver development environment or a development tool 1 is provided to develop a device driver that operates in an operating system of a non-embedded system, where a host system and a target system are not separated, i.e., a development system 4 . However, the prior art arranged as described above has problems in that it requires version-dependent processing that depends on various kernel versions, and it is impossible to be used in the development of the device driver for a Linux embedded system in which a remote development environment is inevitable. SUMMARY OF THE INVENTION The present invention is directed to a driver agent device for supporting a remote device driver development environment in an embedded system, in which a developer can process various services such as retrieving hardware information needed for the development of the device driver, authenticating resources and applying a device driver to a target system, without expert knowledge on the embedded system in a Linux-operated embedded system. The present invention is also directed to an operation method of a driver agent device for supporting a remote device driver development environment in an embedded system, which transmits various serves requested from a device driver development tool of a host system to a target system, determines types of the various services transmitted to the target system, processes the corresponding service depending on the type of the services, and then, transmits the processed service result to the host system. One aspect of the present invention is to a driver agent device for supporting a remote device driver development environment in an embedded system, in which a host system having a device driver development tool and a target system having a device driver are separated from each other and interconnected with a communication network, the driver agent device comprising: communication processing means interconnected with the target system to receive and process various service requests from the device driver development tool of the host system, and to transmit the processed services to the host system through the communication network; core means for determining types of the services requested from the device driver development tool of the host system; and service processing means for performing corresponding services based on the types of the services determined by the core means. In the above aspect, the service processing means includes: a device detection unit for detecting device catalog and information by scanning buses of the target system, in the case that the service determined by the core means is directed to detecting devices mounted on the target system; a device resource authentication unit for providing a read/write access function to the device resources, in the case that the service determined by the core means is directed to authenticating the device resources of the target system; a kernel device information extraction unit for extracting information retained in a device related data structure of the kernel, in the case that the service determined by the core means is directed to requesting kernel information on the devices of the target system, a kernel message detection unit for detecting and collecting the kernel message, in the case that the service determined by the core means is directed to requesting kernel message generated by the kernel of the target system; and a device driver module management unit for installing a device driver transmitted from the host system on a file system of the target system and inserting or deleting the device driver into and from the kernel through a kernel system command, in the case that the service determined by the core means is directed to installation in the target system, start, and end of the device driver module provided on the host system. Another aspect of the present invention is to a method of operating a driver agent device for supporting a remote device driver development environment in an embedded system, in which a host system having a device driver development tool and a target system having a device driver are separated from each other and interconnected with a communication network, the method including: (a) transferring various services requested from the device driver development tool of the host system to the target system; (b) determining types of the various services transferred to the target system; (c) processing corresponding services based on the types of the various services transferred to the target system; and (d) transmitting results of the services processed in the step (c) to the host system. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features of the present invention will be described in reference to certain exemplary embodiments thereof with reference to the attached drawings in which: FIG. 1 is a schematic block diagram showing a device driver development environment for a device driver development support program according to the prior art; FIG. 2 is a schematic block diagram showing a remote device driver development environment for an embedding system using a driver agent device according to an embodiment of the present invention; FIG. 3 is a detailed block digram showing the driver agent device of FIG. 2 ; FIG. 4 is a detailed block diagram showing the service processing module of FIG. 3 ; FIG. 5 is a flowchart illustrating an overall operation method for a service request from a host system by a driver agent device according to an embodiment of the present invention; and FIG. 6 is a detailed flowchart illustrating the service processing of FIG. 5 . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. FIG. 2 is a schematic block diagram showing a remote device driver development environment for an embedding system using a driver agent device according to an embodiment of the present invention; FIG. 3 is a detailed block digram showing the driver agent device of FIG. 2 ; and FIG. 4 is a detailed block diagram showing the service processing module of FIG. 3 . As shown in FIGS. 2 to 4 , in a remote device driver development environment for an embedded system using a driver agent device according to an embodiment of the present invention, a host system 100 having a device driver development tool 150 and a target system 200 having a device driver 250 are separated and interconnected with a communication network 400 . Here, the communication network 400 is preferably implemented with Ethernet, but the present invention is not limited thereto, and thus it can be implemented with typical various wired/wireless communication networks (e.g., PSTN, ADSL, wireless LAN, BLUETOOTH, CMDA, etc.) Further, a driver agent device 300 arranged to support the remote device driver development environment in the aforementioned embedded system is interconnected with the target system 200 . The driver agent device 300 includes a communication processing module 310 for receiving and processing various service requests from the device driver development tool 150 of the host system 100 and transmitting the processed services to the host system 100 ; a core module 320 for determining types of the services requested from the device driver development tool 150 of the host system 100 ; and a service processing module 330 for performing corresponding services based on the types of the services determined by the core module 320 . In the above configuration, the core module 320 serves to call the corresponding service by processing start and end of the driver agent and determining the type of the host request service transmitted from the communication processing module 310 . In addition, the service processing module 330 includes a device detection unit 331 , a device resource authentication unit 332 , a kernel device information extraction unit 333 , a kernel message detection unit 334 , and a device driver module management unit 335 . Here, in the case that the service determined by the core module 320 is directed to detecting the devices mounted on the target system 200 , the device detection unit 331 serves to detect device catalog and information by scanning buses of the target system 200 . In the case that the service determined by the core module 320 is directed to authenticating the device resources of the target system 200 , the device resource authentication unit 332 serves to provide a read/write access function for the device resources. In the case that the service determined by the core module 320 is directed to requesting kernel information for the devices of the target system 200 , the kernel device information extraction unit 333 serves to extract and collect information retained in a device-related data structure of the kernel. In the case that the service determined by the core module 320 is directed to requesting a kernel message generated by the kernel of the target system 200 , the kernel message detection unit 334 serves to extract and collect the kernel message. In the case that the service determined by the core module 320 is directed to installation of the device driver module 250 provided by the host system 100 onto the target system 200 , and start and end thereof, the device driver module management unit 335 serves to install the device driver 250 transmitted from the host system 100 on a file system (not shown) of the target system 200 , and insert or delete the device driver 250 into or from the kernel through a kernel system command. Next, a method of operating a driver agent device for supporting a remote device driver development environment in an embedded system of the present invention having the aforementioned configuration will be described in detail. FIG. 5 is a flowchart illustrating an overall operation method for a service request from a host system by a driver agent device according to an embodiment of the present invention; and FIG. 6 is a detailed flowchart illustrating the service processing of FIG. 5 . Here, note that the process is mainly operated in the driver agent device 300 , unless stated otherwise. As shown in FIGS. 5 and 6 , first, in step 100 , the core module 320 performs an initialization operation, and then waits for a service request from a host system 100 . Next, in step S 110 , the communication processing module 310 determines whether or not the service request is generated from the host system 100 . As a result of the determination in step S 100 , when the service request is not generated from the host system 100 , the process returns to step 100 , and continues to wait for the service request. Further, as a result of the determination in step S 110 , when the service request is generated from the host system 100 , in step S 120 , the communication processing module 310 transfers various services requested from the host system 100 to the core module 320 , and the core module 320 determines which service types various services belong to, i.e., the types of the requested various services, and then calls the corresponding service of the service processing module 330 . Next, in step S 130 , it is determined whether the requested service is an end service of the driver agent. If so, the driver agent is ended. Further, as a result of the determination in step S 130 , when the requested service is not the end service of the driver agent, in step S 140 , the service processing module 330 processes the corresponding service. Next, in step S 150 , the communication processing module 310 transfers the result of the corresponding service to the host system 100 , and the process returns to step S 100 . Here, the service processing in step S 140 includes: detecting device catalog and information by scanning buses of the target system 200 , in the case that the service determined by the core module 320 is directed to detecting the device (step S 141 ); providing a read/write access function for device resources, in the case that the service determined by the core module 320 is directed to authenticating the device resources (step S 142 ); extracting information retained in a related data structure from a kernel, in the case that the service determined by the core module 320 is directed to requesting kernel information on the devices (step S 143 ); detecting a kernel message, in the case that the service determined by the core module 320 is directed to requesting the kernel message (step S 144 ); and transmitting and storing a device driver 250 to the target system 200 , and then inserting or deleting the device driver into or from the kernel, in the case that the service determined by the core module 320 is directed to installing and managing the device driver module in the target system (step S 145 ). The driver agent device for supporting the remote device driver development environment in the embedded system and the operation method thereof as described above are preferably recorded into a recording medium readable with a computer, and processed by the computer. As described above, according to a driver agent device for supporting a remote device driver development environment in an embedded system of the present invention and an operation method thereof, a driver agents device supports the target system in the development process of a device driver, which is a control program of the device mounted on the embedded system, in the remote host system. Therefore, a device driver developer can effectively process various services such as detecting hardware information needed for the device driver development, resource authentication, and application of the device driver to the target system without expert knowledge on the embedded system. In addition, the device driver developer can also develop the device driver more rapidly and easily and test the device driver by applying it to the target system without a complex procedure. Accordingly, time and manpower required in the device driver development can be effectively reduced. Although a driver agent device for supporting a remote device driver development environment in an embedded system according to the present invention and an operation method thereof have been described in preferred embodiments of the present invention, the present invention is not limited thereto. However, a variety of modification can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, which are also included in the present invention.

A host system having a device driver development tool and a target system having a device driver agent, the tool and the target system separated from each other and interconnected with a communication network. The driver agent device communicates with the target system, receiving and processing various service requests from the device driver development tool, and transmits the processed services to the host system through the communication network. Thr driver agent determines types of the services requested from the device driver development tool and performs services based on the types of the services determined. Accordingly, the device driver can be adapted to the target system and tested without complex procedures to effectively reduce time and manpower needed for the device driver development.

This is a continuation-in-part of application Ser. No. 08/014,953, filed Feb. 8, 1994, now abandoned. BACKGROUND OF THE INVENTION This invention is directed to ostomy pouches and more particularly to a novel flushable ostomy pouch. One of the problems associated with ostomy care is the disposal of the ostomy collection pouch after it has been used. If the used pouch is disposed of by flushing down a toilet, there is a risk that the pouch may become trapped in a toilet passage or sewer line, thereby causing plumbing problems. Thus some users empty the contents of the pouch into the toilet and then discard the pouch in the garbage. Other users dispose of the used pouch and its contents in the garbage, which usually necessitates prewrapping of the pouch with paper and/or placement of the used pouch in a plastic bag prior to disposal. Regardless of which measures are taken to dispose of a used ostomy pouch, the process is generally unduly laborious and oftentimes discomforting. Thus there has been an ongoing effort to develop an ostomy pouch that provides relatively trouble-free flushability down a toilet. A major problem in flushing an ostomy pouch down a toilet is that the coupling or securing structure around the waste inlet opening of the ostomy pouch, such as shown in U.S. Pat. No. 4,372,308, can cause the pouch to become trapped in the flow passages of the toilet or in a connecting pipe or sewer line. Efforts have thus been made to form ostomy pouches of materials that soften and become slimy or slippery when contacted with water to promote flowage in pipelines and flow passages. While pouches that become slimy or slippery upon contact with water help minimize clogging and trapping problems associated with flush disposal of ostomy pouches, they can be discomforting if they become wet while being worn. Such pouches might discourage a user from engaging in swimming and other physical activity and would require protective covering while showering. Furthermore, such pouches may still cause clogging in toilets with relatively low volume flush capacity. Another structure that facilitates flush disposal of ostomy pouches is that of U.S. Pat. No. 4,830,187, which shows a carrier sleeve or bag into which a pouch can be placed before flush disposal. The sleeve or bag forms a slimy or slippery layer when exposed to water, thereby sliding on surfaces that might otherwise cause snagging of the pouch. However, since the carrier sleeve conforms to the pouch during flushing, a pouch with a coupling that is not flexible enough to negotiate the flow passages in a toilet may still become trapped even with a slippery carrier sleeve. It is thus desirable to provide an ostomy pouch that can be adapted to easily flush down a toilet, even a water-saver toilet, and which has an optimum height, width, and convergence angle to facilitate flush disposal. OBJECTS AND SUMMARY OF THE INVENTION Among the several objects of the invention may be noted the provision of a novel ostomy pouch, a novel ostomy pouch that can be disposed of by flushing down a water-saver toilet, a novel ostomy pouch with a detachable coupling member, a novel ostomy pouch with a detachable coupling member that can be separated from the pouch prior to disposal of the pouch, a novel ostomy pouch having a coupling member that can be separated from the pouch as a unit without damaging the pouch to facilitate flush disposal of the pouch, a novel ostomy pouch with a detachable coupling member that can be reused, a novel ostomy pouch which has a converging streamlined shape from top to bottom with an optimum angle of convergence, optimum width, and optimum height to facilitate flush disposal in a water-saver toilet, and a novel method for facilitating flush disposal of an ostomy pouch. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter. In accordance with the invention, the flushable ostomy pouch includes an envelope formed of flexible plastic sheet material that defines a waste collection chamber for body waste that passes through a stoma. A waste inlet opening is formed in the envelope for passage of waste material from the stoma into the collection chamber. Coupling means are provided on the envelope around the waste inlet opening for positioning the waste inlet opening around the stoma. The coupling means can be formed of molded annular plastic to mechanically interengage with a complementary shaped coupling portion provided around the stoma. The coupling member is detachably bonded to the envelope so as to permit removal from the envelope prior to flushing the pouch in a toilet. The bonding agent which joins the coupling member to the envelope has a predetermined bond strength that permits the coupling member to be peeled as a unit from the envelope. Thus the removal of the coupling means from the pouch facilitates flush disposal of the envelope even in a water-saver toilet which has less water volume flush capacity than a standard toilet, and minimizes the likelihood that the flushing of the pouch will result in trappage within the sewer line. The removed coupling member can be discarded or reused on a replacement pouch. In European wash down water closets, when the pouch is ready for disposal, the top portion of the pouch can be cut or otherwise ripped to permit evacuation of the contents of the collection chamber during the flush process. Preferably the envelope has opposite side edges that converge from the top portion of the envelope to the bottom portion such that the envelope in plan view is substantially V-shaped. The top width, pouch height and convergence angle are of a predetermined magnitude to assure optimum flushability of the pouch. The pouch is placed bottom end down and can be deposited in a toilet with a sleeve or bag that becomes slippery upon contact with water. The invention accordingly comprises the constructions and method hereinafter described, the scope of the invention being indicated in the claims. DESCRIPTION OF THE DRAWINGS In the accompanying drawings, FIG. 1 is a simplified perspective view of an ostomy pouch incorporating one embodiment of the invention, prior to being coupled to a support flange provided around the stoma; FIG. 2 is a simplified perspective view thereof after the pouch has been coupled to the support flange; FIG. 3 is a plan view thereof; FIG. 4 is a sectional view thereof, taken on the line 4--4 of FIG. 3; FIG. 5 is a sectional view thereof, taken on the line 5--5 of FIG. 2; FIG. 6 is a view similar to FIG. 5, showing the pouch, after use, uncoupled from the support flange; FIG. 7 is a simplified perspective view thereof, after the coupling member and the pouch envelope have been separated; and FIG. 8 is a plan view of a carrier sleeve which can be used to flush an ostomy pouch in accordance with the present invention; and FIG. 9 is a plan view of an ostomy pouch in accordance with the present invention having a cut in its top portion. Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE INVENTION An ostomy pouch incorporating one embodiment of the invention is generally indicated by the reference number 10 in FIG. 1. The pouch 10 is formed of a suitable known thermoplastic material that is gas and water impermeable, flexible and expandable. The pouch 10 includes a front wall 12 that faces away from the abdomen 13, and a rear wall 14 that confronts the abdomen 13, joined together by a peripheral thermoweld 16. The pouch 10 further includes a top portion 18 with rounded corners, and opposite side portions 20 and 22 that converge from the top portion 18 to a rounded bottom portion 26. In a preferred embodiment of the pouch 10, the height of the pouch is approximately 7.750 inches, the maximum width of the top portion 18 at the rounded corners is approximately 5.125 inches, the bottom portion 26 has a radius of approximately 1.750 inches and the angle of convergence of the side portions 20 and 22 is approximately 15°. The walls 12 and 14 are approximately 17 to 45 microns thick. A preferred size range for the pouch 10 is approximately 4.5 to 6 inches maximum width of the pouch, approximately 6 to 8 inches pouch height and a convergence angle of approximately 15° to 25°. A waste inlet opening 30 is formed in the rear wall 14 nearer the top portion 18 of the pouch 10 than the bottom portion 26. The waste inlet opening 30 is bordered by a plastic coupling ring 32 (FIG. 7) having a base portion 34 and a bottom surface 36. A contact adhesive 38 (FIG. 7) is provided on an outside surface 44 of the rear wall 14 in the form of a washer-shaped wafer approximately 0.010 to 0.015 inches thick, to bond the bottom surface 36 of the coupling ring 32 to the rear wall 14. Preferably the adhesive 38 is of a type that securely joins the coupling ring 32 to the rear wall 14 to prevent axial removal of the ring 32. However, the adhesive is selected to permit peeling of the coupling ring 32 from the rear wall 14 without damaging the rear wall. A suitable adhesive 38 is a hydrocolloid adhesive such as Stomahesive®, manufactured by Bristol-Myers Squibb Company. The adhesive wafer can be covered with a known silicone release paper (not shown) that is removed prior to installation of the coupling ring 32. Thus the coupling ring 32 can be easily positioned on the rear wall 14 by the user or the manufacturer. The base portion 34 of the coupling ring 32 has a peripheral edge 46 with a generally concave touch indicator notch or recess 48. Preferably the coupling ring 32 is positioned such that the recess 48 is at the 12 o'clock position as shown in FIG. 4. The indicator notch 48 permits touch detection of an initial peel section of the coupling ring 32 at the area of the notch 48. The coupling ring 32 further includes an annular rim 50 projecting away from the base portion 34. An annular engagement slot 52 formed in the rim 50 includes an undercut latch portion 54. An inner peripheral surface 56 of the rim 50 encircles the waste inlet opening 30 at the rear wall 14. Referring to FIGS. 1, 5 and 6, the coupling ring 32 is adapted to interlock with a complementary shaped coupling ring 60 on a mounting plate 62 which is adapted to adhere to the abdominal wall 13 in any suitable known manner. A central opening 68 in the mounting plate 62, which aligns with the stoma 70, is surrounded by an annular latch projection 66 that interlocks in the engagement slot 52 of the coupling ring 32. Preferably the coupling ring 60 and the mounting plate 62 are formed as a two-part structure wherein an annular base portion 72 of the coupling ring 60 is bonded to an annular channel 74 of the mounting plate 62. An S-shaped gas evacuation slit 78 or other suitable gas evacuation outlet is formed in the rear wall portion 14 of the pouch 10 near the top and side edges 18 and 20, offset from the coupling ring 32. A generally circular deodorizing filter 80 of the type shown in U.S. Pat. No. 5,074,851, is provided at an inside surface 82 of the rear wall 14 in substantial alignment with the gas evacuation slit 78. In using the ostomy pouch 10, the mounting plate 62 is first adhered to the abdominal wall 13 to align the central opening 68 with the stoma 70. The coupling ring 32 is installed on the rear wall 14 of the pouch 10 and engaged with the coupling ring 60 of the mounting plate 62 to interlock the latch projection 66 in the engagement slot 52 as shown in FIG. 5. A leak tight joint is thus established around the stoma 70 which also aligns with the waste inlet opening 30 of the ostomy pouch 10. Waste material 88 (FIG. 6) that issues from the stoma 70 passes into a waste collection chamber 90 of the pouch 10. When an adequate amount of the waste material 88 accumulates in the collection chamber 90, the pouch 10 is ready for disposal. To facilitate flush disposal of the used pouch, the welded wall portions 12 and 14 which constitute the envelope 12-14 of the pouch are separated from the coupling ring 32. Separation of the coupling ring 32 can be accomplished by peeling the rear wall 14 away from the base portion 36 of the coupling ring 32 while the coupling ring 32 is engaged with the coupling ring 60. The adhesive bond between the coupling ring 32 and the tape 38 is of a predetermined strength that can be overcome by peeling without causing separation of the coupling rings 32 and 60. The peeling operation is initiated at the touch indicator notch 48 which is sized to permit finger engagement with the coupling ring 32. Separation of the envelope 12-14 from the coupling ring 32 can also be accomplished by initially disengaging the coupling rings 32 and 60 and then peeling the ring 32 from the rear wall 14. Coupling disengagement is obtained by pressing a finger between the couplings 32 and 60 to release the pouch 10 from the mounting plate 62. The coupling ring 32 can then be peeled from the rear wall 14 while the ostomy pouch 10 is held at the top portion 18. Once the coupling ring 32 is separated from the rear wall 14, the envelope 12-14, minus the coupling ring 32, can be flushed down a water-saver toilet, preferably with a carrier sleeve 91 (FIG. 8) of the type shown in U.S. Pat. No. 4,830,187. In European wash down water closets, the carrier sleeve 91 can be omitted. However, the top portion 18 is preferably cut or ripped (FIG. 9) to permit evacuation of confined waste during the flushing process. The envelope 12-14 is deposited in a toilet, bottom portion first. The convergent shape of the pouch 10 and the non-obtrusive adhesive wafer 38 enable the envelope 12-14 to flow in streamlined fashion through the toilet passages and sewer pipes. It has been found that flushability of the pouch 10 is enhanced when the pouch has a 15° to 25° angle of convergence and the width and pouch height are in the size ranges previously specified. The removed coupling ring can be separately discarded in a garbage container or reused on a replacement envelope 12-14 that has an adhesive wafer 38 covered by silicone release paper. The release paper is thus removed and the coupling 32 installed. The replacement pouch 10 can then be interlocked with the coupling 60 on the abdominal wall 13. Some advantages of the present invention evident from the foregoing description include an ostomy pouch that has a molded plastic coupling ring that can be removed from the pouch envelope to facilitate flush disposal of the envelope in a water-saver toilet. Removal of the coupling ring is easily accomplished by peeling from the pouch wall. The removed coupling ring can either be reused or discarded. The pouch envelope can be supplied to the user without the coupling ring so as to permit reuse of a single coupling ring. The V-shaped profile of the pouch, the thin walled structure of the pouch envelope, and the thin gauge of the adhesive wafer on the pouch envelope and the predetermined size range of pouch height, top width and convergence angle ensure that the pouch structure itself will not constitute an obstacle to flushability of the pouch, even in low flush volume toilets. The pouch thus provides substantially risk-free flush disposal capability and eliminates the need to resort to garbage disposal of a used ostomy pouch. In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes can be made in the above constructions and method without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

The ostomy pouch has a coupling member that can be removed from the pouch envelope to permit flush disposal of the envelope without the coupling member. Flushability of the pouch is further enhanced by forming the pouch with converging side walls. Thus when the pouch is deposited in a toilet bottom end first in a carrier sleeve, the pouch can flow in streamlined fashion through the passages of a toilet and any sewer pipe or septic line connected to the toilet. Depending upon the flush capacity of the toilet and the flow rate of water through the toilet and sewer line, the ostomy pouch can be deposited in the toilet without a carrier sleeve.

FIELD OF THE INVENTION This invention relates to the field of portable paint spraying equipment, more particularly to equipment suitable for spraying lines on parking lots and the like. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a left-side elevation view of a portable paint spraying apparatus in a non-line-striping configuration. FIG. 2 is a left-side elevation view of the portable paint sprayer apparatus of FIG. 1 coupled to a line sprayer accessory and arranged in a line-striping configuration. FIG. 3 is a simplified top plan view of a portion of the cart of FIG. 1. FIG. 4 is a perspective view of the line striper accessory suitable for use with the paint sprayer of FIG. 1. FIG. 5 is a top plan view of the line striper accessory. FIG. 6 is a bottom plan view of the line striper accessory. FIG. 7 is a right-hand side elevation view of the line striper accessory. FIG. 8 is a rear elevation view of the line striper accessory with spray gun attached for line striping duty. FIG. 9 is a front elevation view of the line striper accessory of FIG. 8. FIG. 10 is a detailed view of a locking mechanism for the castor assembly of the present invention. FIG. 11 is a fragmentary section view taken along 11--11 of FIG. 10. FIG. 12 is a detailed view of the paint gun clamp and actuator seen from below. DETAILED DESCRIPTION Referring now to the figures, and most particularly to FIG. 1, a portable paint sprayer 10 may be seen. Sprayer 10 preferably includes a cart 12, having a pair of wheels 14 spaced apart (see FIG. 3). Wheels 14 are preferably carried by an axle 16. In a conventional painting configuration such as shown in FIG. 1, cart 12 also rests on a pair of legs 18. In this configuration, a spray gun 20 is supplied with paint via hose 22, but is otherwise unrestrained so as to permit operator to grasp gun 20 and move it to apply paint as desired. In the configuration shown in FIG. 1, paint is drawn from a bucket 24 via a paint pump intake 26. Referring now also to FIG. 3, cart 12 preferably also has a transverse support 28 extending parallel to axle 16. Referring now most particularly to FIGS. 2 and 4, a line striper accessory 30 may be seen. Line striper 30 preferably includes an elongated support frame 32 having a first end 34 and a second end 36. Accessory 30 also has a castor assembly 38 located at the first end 34 of frame 32. Castor assembly has a vertical castor axis 40 about which castor assembly 38 may swivel. Assembly 38 has at least one and preferably two wheels 42 mounted in a yoke 44. Wheels 42 preferably have a horizontal axle 46. The line striper 30 also preferably has a locking mechanism 48 (see FIGS. 10 and 11) which is operable to a first position (as shown in FIGS. 10 and 11) to prevent swiveling the castor assembly when the castor wheel axle 46 is transverse to frame 32. Locking mechanism 48 is movable to alternate locking positions to position the castor assembly 38 to provide a fixed turning radius for the line striper 30. In the first position, a spring biased releasable pin 50 located on frame 32 is engageable with one of a plurality of apertures 52 in yoke 44. In the second position of locking mechanism 48, pin 50 is retracted or disengaged from yoke 44. Pin 50 is actuated by a flexible cable 54 connected to a hand grip actuator for selectively activating the locking mechanism 48. Line or paint striper 30 also preferably has handlebars 58, 60 which include hand grips 62, 64. It is to be understood that handlebars 58, 60 extend from frame 32 to grips 62, 64 to permit an operator to grasp and propel the line striper 30. Line striper 30 also has cart securing means positioned along the frame 32 for securing the cart 12 to the frame such that the combined cart and frame (as shown in FIG. 2) is supported by wheels 14 of the cart 12 and the castor assembly 38. In particular, the cart securing means includes a first supporting means in the form of a V-shaped channel 66. Channel 66 supports transverse member 28 of cart 12 on frame 32 proximate the second end 36 of frame 32. The cart securing means also includes a second supporting means for supporting the frame 32 on the cart 12 (more particularly on axle 16) intermediate the first and second ends 34, 36 of frame 32. A pair of U-clamps 68 may be received around axle 16 and secured to slots 70 in frame 32. Line striper accessory 30 also preferably has a receptacle portion 72 adapted to hold paint bucket 24. Receptacle 72 is made up of a transverse base plate 74 and a surrounding frame 76. Line striper 30 also preferably includes a spray gun mounting apparatus 80 as is shown most clearly in FIGS. 4 and 12. Apparatus 80 includes a first tubular extension 82 which may be secured to frame 32 via a thumb screw 84. A right angle clamp 86 joins a second extension 88 to first extension 82. A gun mounting block 90 is preferably mounted to second extension 88 and secured thereto via a thumb screw 92. A further thumb screw 94 may be used to clamp gun 20 in block 90. A transverse projecting finger 96 engages a trigger 98 in gun 20 when gun 20 is mounted in block 90. Finger 96 is biased to the position shown in FIG. 12 via a pair of springs 100, 102 and is selectively capable of being retracted towards block 90 via flexible cable 104. As may be seen most clearly in FIG. 4, cable 104 is actuatable via a handlebar actuator 106 when it is desired to stripe paint by actuating gun 20. Referring now again to FIG. 2, it may be seen that an extended suction set 110 may be used to draw paint from bucket 24 when the combination of sprayer 10 and accessory 30 is configured for line striping. This permits a close approach to a curb 112 which would not be possible with the paint bucket 24 in the configuration shown in FIG. 1, even though such configuration would be possible for striping because bucket 24 is supported by bail 114 on hook 116 when the sprayer 10 is elevated as shown in FIG. 2. In other words, if it is not required to have a close approach to curb 112, direct suction of paint may be utilized, as indicated in FIG. 1, even while sprayer 10 is configured on striper 30 as shown in FIG. 2. It is also to be understood that additional spray guns may be mounted on apparatus 80 to spray parallel lines or, alternatively, one or more additional spray guns may be mounted on a second apparatus (not shown) which would extend from alternate extension 118 (see FIG. 4) which is secured by thumb screw 120. In FIG. 4, extension 118 is shown in a storage position or configuration. It is also to be understood that it is preferable, although not necessary, to rotate handle 122 of sprayer 10 from the position shown in FIG. 1 to that of FIG. 2 to permit ready access to the receptacle portion 72 when it is desired to insert a bucket, add paint or solvent, or remove bucket 24. The invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention.

A line striper accessory for combining with a conventional paint sprayer mounted on a wheeled cart utilizing the cart wheels and a castor assembly to support the combined cart and line striping accessory. The accessory includes handlebars having actuators to selectively actuate a locking mechanism and the spray gun mounted on the accessory for providing paint stripes on the surface over which the striper is rolled.

FIELD OF INVENTION This invention relates to a toy embroidery apparatus. In particular, this invention relates to an apparatus for undertaking an embroidery stitch with a minimal risk of injury to an operator. BACKGROUND OF INVENTION Toy sewing machines, intended for use by children, are readily available in the marketplace. However, such apparatus must operate in a failsafe manner in which a child could not inadvertently operate the apparatus in a manner which could cause injury to the child or others. SUMMARY OF THE INVENTION The disadvantages of the prior art may be overcome by providing a toy embroidery apparatus having a shroud for protecting the penetration of the needle during use and a switch which locks the shroud in place and which controls the energizing of the apparatus for use. According to one aspect of the invention, there is provided a toy embroidery apparatus having a needle mounted within the housing. An arm is pivotally mounted on the housing for movement between an operational position and a standby position. When the arm is in the operational position, a tubular shroud encloses a tip of the needle as it reciprocates and prevents the arm from pivoting until the tip of the needle is fully retracted within the housing. A drive effects reciprocating movement of a tip of the needle in and out of the housing. A switch selectively energizes the drive. The switch is rotatable between a locked condition wherein the arm is locked in the operational position and the drive is selectively energizable and an unlocked condition wherein the arm is pivotable. DESCRIPTION OF DRAWINGS In drawings which illustrate the embodiment of the invention, FIG. 1 is a perspective view of the present invention; FIG. 2 is a top plan view of the embodiment of FIG. 1; FIG. 3 is a side elevational view of the embodiment of FIG. 1; FIG. 4 is an end elevational view, partly in section, of the embodiment of FIG. 1; FIG. 5 is sectional view of the switch of the embodiment of FIG. 1; FIG. 6 is an end view of the motor and gear arrangement of the embodiment of FIG. 1; FIG. 7 is a top plan view of embodiment of FIG. 1 illustrating the operational and standby positions; FIG. 8 is a bottom sectional view of the embodiment of FIG. 1; FIG. 9 is a side sectional view of the embodiment of FIG. 1; FIG. 10 is a partial section view of an end elevational view of the embodiment of FIG. 1; and FIG. 11 is a side elevational view of an embroidery needle of the embodiment of FIG. 1. DESCRIPTION OF THE INVENTION Referring to FIGS. 1, 2 and 3, the toy embroidery apparatus 10 of the present invention generally comprises a hollow housing 12, an arm 14 and a cover plate 16. Housing 12 is generally hollow and defines an upper planar surface 18. Cover plate 16 is hingedly mounted at one end of housing 12. Cover plate 16 has an upper planar surface 20. When the cover plate 16 is in a closed condition, surfaces 18, 20 are substantially co-planar defining a sewing platform. Arm 14 is pivotally mounted to housing 12 at pivoting end 22. Shroud 24 is mounted at the end opposite pivoting end 22. Arm 14 is contoured to extend over planar surface 18 and to space shroud 24 slightly above the junction between co-planar surfaces 18, 20. Shroud 24 is substantially tubular. Preferably, shroud 24 is made of a transparent or clear plastic material to permit the operator to watch the embroidery needle in operation. Arm 14 is also provided with bubble 26 which is mounted on the upper surface of arm 14 but in vertical alignment with shroud 24. Bubble 26 is preferably made of a clear plastic providing visual access to the operation of the embroidery needle. At the pivoting end of arm 14, knob 28 operates the locking mechanism of the arm 14 and also energizes the operation of the embroidery needle. Referring to FIGS. 4 and 5, arm 14 may be pivotally mounted to housing 12 in any known manner. In the present embodiment, planar surface 18 has a circular aperture adapted to receive a circular flange 30 extending downwardly from the base of arm 14. A retainer plate 32 is fastened from within housing 12 to the base of arm 14. Extending between the center of rotation of the pivot of arm 14 and the centre of bubble 26 is an imaginary longitudinal axis. Extending substantially parallel to this imaginary axis is slot 34 in the base of arm 14. Planar surface 18 is also provided with a longitudinal slot 36 which will communicate with slot 34 when arm 14 is in an operational position. Knob 28 is rotatably mounted on the side of arm 14. Inside of arm 14, switch plate 38 is mounted to the stem 40 of knob 28. As is apparent, switch plate 38 will rotate as knob 28 rotates. Switch plate 38 is in substantial alignment with slot 34 such that when knob 28 rotates switch plate 38 will rotate to extend through slot 34 and slot 36 when arm 14 is in an operational condition. Mounted within housing 12 is switch 42. Switch 42 is positioned such that when switch plate 38 is rotated through slots 34 and 36, it will engage a contact lever of the switch for activating same. When arm 14 is rotated from the operational position, slots 34 and 36 will no longer align. Accordingly, switch plate 38 is unable to rotate and engage switch 42 for activation of the embroidery needle. Equally, when switch plate 38 is extending through slots 34 and 36, arm 14 is locked in the operational position and is unable to pivot and thereby preventing access to the embroidery needle. As illustrated in FIG. 6, motor 44 is mounted internally of housing 12 and has a drive shaft on which a driving gear is mounted. Driving gear engages and drives a driven worm gear 46. Worm gear 46 engages driven gear 48. Cam 50 is mounted on a common axle with driven gear 48. Upon rotation of driven gear 48, cam 50 urges cam plate 52 to move in a reciprocating manner. Such arrangement is well known in the art and described in detail in Canadian Patent No. 344,063. Referring to FIGS. 8, 9, 10 and 11, needle mount 54 is mounted on cam plate 52 within slide housing 56. Slide housing 56 is adapted to allow needle mount 54 to slide up and down in a reciprocating manner. Mounted within needle mount 54, is hollow embroidery needle 58. At the base of slide housing 56 is a thread entry slot 60. At the upper end of slide housing 56 is capsule 62 having an aperture through which embroidery needle 58 extends. Spool holder 64 is mounted within cover 16. A spool 66 having thread 68 wound thereabout, is mounted such that thread 68 may be threaded through thread entry slot 60 upwardly through the hollow needle 58 and exit out the point. A wire having a thread grasping end may be used to facilitate the threading of needle 58. Further, a thread guide 72 may also be used to direct the thread from the spool 66 to the thread entry slot 60. Housing 12 has a battery compartment 74 for housing batteries required for operation of the apparatus 10. Cover plate 76 closes battery compartment 74 in a manner well known in the art. Motor 44 is electrically connected with the electrical battery source via switch 42. Closing switch 42 will energize motor 44 driving the various gears. Needle 58 is mounted on needle mount 54 such that when needle mount 54 is at the lower end of slide housing 56, the tip of the needle is within capsule 62. Capsule 64 has a convex surface. The diameter of the convex surface is approximately the same as the inside diameter of the shroud 24. In the upper limit of stroke of needle mount 54, the tip of needle 58 will extend upwardly into shroud 24. In use, a piece of cloth 78 is placed about an embroidery hoop 80 as is well known in the art and described in more particular detail in Canadian Patent No. 1,010,077. A pattern 82 can be provided to the cloth 78 mounted on the embroidery hoop 80. Embroidery hoop comprises an outer hoop and an inner hoop. Knob 84 opens and closes the outer hoop about the inner hoop gripping the cloth 78 therebetween. Arm 14 is rotated from a standby position until shroud 24 covers capsule 62. In this operational position, slots 34 and 36, will be in substantial alignment allowing rotation of knob 28 and switch plate 38 to extend through slots 34, 36 for engagement and activation of contact switch 42. The switch is activated until needle mount 54 is in the bottom of slide housing 56 or at the bottom stroke of embroidery needle 58. In this position, the tip of the needle 58 is retracted from the shroud 24. Knob 28 is rotated, rotating switch plate 38 out of slots 34 and 36 to an unlocked condition. Arm 14 is free to pivot about its axis to a standby position. Since needle 58 is at the bottom of the stroke, the tip is below capsule 62 allowing free pivoting of arm 14. The embroidery cloth 78 and hoop 80 can be placed over the capsule 62 with the embroidery hoop resting upon surface 18, 20. Arm 14 is rotated back into the operation position. Shroud 24 is spaced from the outer perimeter of capsule 62 a distance which permits the cloth to extend over the convex surface thereof but will not permit an operator's fingers to be inserted into the path of the tip of the reciprocating embroidery needle 58. Knob 28 can be rotated, rotating switch plate 38 for activation of motor 44 which will cause reciprocal motion of embroidery needle 58. The operator uses one hand to manipulate knob 28 while manipulating the embroidery hoop to position the cloth at the desired location for penetration by embroidery needle 58. In this manner, an embroidery stitch is facilitated by the apparatus 10. To remove the cloth and embroidery hoop, the apparatus 10 is moved into its unlocked condition allowing arm 14 to be pivoted away from capsule 62 to its standby position, allowing removal of the cloth and the embroidery hoop. Since the embroidery stitch is a non-interlocking stitch, the loop portions of the stitch may glued to the cloth for permanent attachment thereto. The apparatus 10 of the present invention has two locking systems for preventing unsafe usage of the apparatus. First, the motor 44 cannot be energized unless the arm 14 is in the operational position with the shroud 24 substantially enclosing the tip of the embroidery needle 58 as it reciprocates. Second, the arm 14 cannot be pivoted from the operational position to the standby position unless the tip of the embroidery needle 58 is fully retracted within the housing 12. Both of these systems operate to substantially minimize the risk of accidental injury to the operator of the apparatus 10. Although the disclosure describes and illustates the preferred embodiment of the invention, it is understood that the invention is not limited to this particular embodiment. Many variations and modifications will now occur to those skilled in the art. For definition of the invention, reference is made to the appended claims. In particular, the knob 28 and switch plate 38 could be mounted within housing 12 and still achieve the dual function of locking the arm 14 in the operational position and energizing the motor 44.

A toy embroidery apparatus has a needle mounted movement reciprocally within the housing. An arm is pivotally mounted on the housing for movement between an operational position and a standby position. When the arm is in the operational position, a tubular shroud encloses a tip of the needle as it reciprocates and prevents the arm from pivoting until the tip of the needle is fully retracted within the housing. A drive effects reciprocating movement of a tip of the needle in and out of the housing. A switch selectively energizes the drive. The switch is rotatable between a locked condition wherein the arm is locked in the operational position and the drive is selectively energizable and an unlocked condition wherein the arm is pivotable.

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority of German Patent Application No: DE 10 2005 022 715.5, filed on May 18, 2005, the subject matter of which is incorporated herein by reference. BACKGROUND OF THE INVENTION The invention generally relates to a circuit arrangement that may be used to generate light pulses. Circuit arrangements of this type are used in particular as transmitting units for optical sensors. These optical sensors can be embodied as distance sensors, which typically operate based on the light transit time method. For the distance measuring, light pulses are generated with predetermined timing with the aid of the circuit arrangement of the transmitting unit. The transit time of a light pulse to the object and back to the optical sensor is evaluated as a measure of the distance between an object and the optical sensor. To achieve a highly precise distance measurement, it is necessary to generate sequences of very short light pulses, wherein the pulse duration of a light pulse typically is approximately one nanosecond. Accordingly, light pulses of this type are also required to have extremely short rise times below one nanosecond. Circuit arrangements of this type for generating the aforementioned short light pulses are provided with laser diodes functioning as electro-optical converters. A charge store, typically a charge capacitor, is connected to this laser diode by way of a switching element, for example, a transistor. The charge capacitor is discharged by closing the switching element and, in the process, a current pulse is generated, which is then converted in the laser diode to a light pulse. With ideal components for such a circuit arrangement, the resulting time history for the current pulse would correspond to a discharge of an ideal RC (resistance-capacitance) element. This would mean an infinitely rapid rise time for the current pulse and an exponential decay of the current pulse. However, during actual operations system-related deviations occur from the ideal time history of such current pulses, wherein these deviations in particular are caused by parasitic inductances in the components used. A first deviation is that a finite rise time is obtained for the current pulse in place of an infinitely rapid rise time. Furthermore, the time history of the current pulse takes the form known for the discharge of an RLC (resistance-inductance-capacitance) element. Accordingly, post-oscillations occur during the decay of the current pulse. These post-oscillations comprise negative undershoots which are followed by positive overshoots. The negative undershoots polarize the laser diode in non-conducting direction and result in a Zener breakdown of the pn junction for the laser diode, thereby drastically reducing its operating life. If the positive overshoots of the current pulse exceed a specific amplitude value, additional parasitic light pulses can thus be generated in the laser diode which follow the actual light pulse and result in distorting the distance measurements. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a circuit arrangement of the aforementioned type, which makes it possible to generate light pulses with the lowest possible rise times and without interfering post-oscillations. This object may be achieved using various embodiments of the invention, as claimed. In one embodiment, a circuit arrangement for generating light pulses, comprising: an electro-optical converter; a switching element; a charge store, wherein the electro-optical converter is connected to the charge store via the switching element, and wherein the closing of the switching element triggers a discharging process in the charge store and, in the process, generates an electrical pulse that is converted to a light pulse in the electro-optical converter; and first and second impedance matching circuits arranged, respectively, between the charge store and the switching element and between the switching element and the electro-optical converter. The basic idea behind the invention is that super-imposed current and/or voltage waves cannot form owing to the impedance matching according to the invention with the aid of the matching circuits arranged between the charge store and the switching element, as well as between the switching element and the electro-optical converter, which is preferably a laser diode. Current and voltage waves of this type, which travel between the components of the circuit arrangement and are reflected back by these, are the main reason for the appearance of post-oscillations in the current pulses generated in the circuit arrangement. Avoiding or at least significantly reducing the current and voltage waves systematically prevents post-oscillations in the current pulses, in particular negative undershoots that result in shortening the operating life of the laser diode functioning as electro-optical converter. Also avoided are positive overshoots, which would result in the emission of undesirable parasitic light pulses by the laser diode. Furthermore, the circuit arrangement according to the invention makes it possible to significantly shorten the rise times for the current and light pulses. The circuit arrangement according to the invention can therefore be used particularly advantageously as a transmitting unit in optical sensors, in particular in distance sensors operating based on the light-transit time method, wherein these sensors make it possible to realize highly precise and fast distance measurements. The matching circuits for eliminating current and voltage waves traveling between the components of the circuit arrangement have a simple layout and can be produced cost-effectively, wherein the circuit arrangement components in general can be active and/or passive components. The components of the matching circuits are generally dimensioned such that parasitic inductances of the charge store, the switching element, and the electro-optical converter are taken into account. The matching circuits consequently simulate circuit lines with defined wave resistances and limit frequencies, which eliminate or at least strongly reduce the reflections of current and voltage waves between the charge store and the switching element, as well as between the switching element and the electro-optical converter. According to one advantageous embodiment of the invention, a first matching circuit is provided as a separate unit for adapting the internal resistance of the charge store to the complex input resistance of the switching element. A second matching circuit is furthermore provided as separate unit for matching the impedance between switching element and electro-optical converter. With this type of embodiment, the charge store in particular can be a single charge capacitor. According to a different, advantageous embodiment of the invention, the first matching circuit can be integrated into the charge store. In that case, the charge store preferably comprises a multiple-unit arrangement of charge capacitors which form a circuit network together with the components of the first matching circuit. BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of the invention will be further understood from the following detailed description of the preferred embodiments and with reference to the accompanying schematic drawings, in which: FIG. 1 shows a schematic representation of a circuit arrangement for generating light pulses, as disclosed in prior art; FIG. 2 shows the time history for an ideal current pulse generated with the circuit arrangement according to FIG. 1 ; FIG. 3 shows the time history for an actual current pulse generated with the circuit arrangement according to FIG. 1 ; FIG. 4 shows a schematic representation of a first embodiment of the circuit arrangement according to the invention for generating light pulses; FIG. 5 shows a detailed representation of a circuit arrangement according to FIG. 4 ; FIGS. 6 a and 6 b illustrate the time histories for partial current flows in the circuit arrangement according to FIG. 5 ; FIG. 6 c shows the time history for a current pulse and a light pulse generated with the circuit arrangement according to FIG. 4 ; and FIG. 7 shows a detailed representation of a second embodiment of the circuit arrangement according to the invention for generating light pulses. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS FIG. 1 shows a circuit arrangement 1 according to prior art for generating short light pulses. The arrangement comprises an electro-optical converter in the form of a laser diode 2 that emits laser light. To enable the laser diode 2 to emit short light pulses, preferably in the nanosecond range, the laser diode is connected via an electronic switching element 3 to a charge store, which for the present case is a charge capacitor 4 . The switching element 3 is a transistor, typically an avalanche transistor. To generate a light pulse, an external trigger signal is used to close the switching element 3 . As a result, the charge capacitor 4 is discharged and, in the process, a current pulse i(t) is generated, which travels through the laser diode 2 and is converted in the laser diode 2 to a light pulse p(t). FIG. 2 shows the time history of the current pulse i(t), which essentially corresponds to the time history of the light pulse p(t) if the components of the circuit arrangement 1 are ideal components. In the ideal case, the current pulse has an infinitely short rise time and an exponential decay behavior, corresponding to the characteristic of a RC element. However, system-related inherent parasitic inductances for the components of the circuit arrangement 1 , as well as connection inductances of the transistor and the laser diode 2 , cause general deviations from this ideal time history for the current pulse i(t). FIG. 3 shows the actual time history for the current pulse i(t) of the circuit arrangement 1 according to FIG. 1 . Parasitic inductances in the circuit arrangement 1 will result in a finite rise time of the current pulse i(t). As a result of the existing parasitic inductances, the current pulse i(t) decay behavior corresponds to that of an RLC element, and no exponential decay of the current pulse occurs, as shown in FIG. 3 . Rather, the positive current pulse i(t) is followed by a negative undershoot I, which is followed by a positive overshoot II. Undershoots of this type polarize the laser diode 2 in the non-conducting direction and cause a Zener breakdown of the pn junction, thereby considerably reducing the operating life of the laser diode 2 . In the event that positive overshoots exceed specific amplitude values, these generate additional parasitic light pulses on the light pulse generated with the current pulse i(t). If the circuit arrangement 1 is used for realizing a distance measurement according to the light-transit time method, for example, these parasitic light pulses lead to distortions in the distance measurements. FIG. 4 illustrates the basic layout of an exemplary embodiment of the circuit arrangement 1 according to the invention, which is designed to eliminate for the most part the interfering influences caused by parasitic inductances within the circuit arrangement 1 . Corresponding to the circuit arrangement 1 shown in FIG. 1 , the circuit arrangement 1 according to FIG. 4 also comprises a laser diode 2 with a charge capacitor 4 and a switching element 3 connected thereto. The switching element 3 can again be a transistor, for example, an avalanche transistor, a MOSFET transistor, or an IGBT transistor. A first matching circuit 5 is provided between the charge capacitor 4 and the switching element 3 to eliminate the aforementioned interfering influences. A second matching circuit 6 is furthermore provided between the switching element 3 and the electro-optical converter. FIG. 5 shows the circuitry which can be realized for the circuit arrangement 1 according to FIG. 4 . The switching element 3 in this case is an avalanche transistor. The charge capacitor 4 is connected via a resistance 7 to a voltage supply U B . FIG. 5 furthermore shows the existing parasitic inductances 8 a - 8 d present in the circuit arrangement 1 , wherein these are attributed to the charge capacitor 4 , the switching element 3 , and the laser diode 2 as components of the circuit arrangement 1 . The two matching circuits 5 , 6 are provided to eliminate the influence of these parasitic inductances 8 a - 8 d. In the present case, the first matching circuit 5 comprises two RC elements R 1 C 1 and R 2 C 2 . The second matching circuit 6 also comprises two RC elements R 3 C 3 and R 4 C 4 . The parasitic inductances 8 a - 8 d are taken into account for the dimensioning of the RC elements in both matching circuits 5 , 6 . The first matching circuit 5 consequently functions to adapt or match the inherent complex resistance of the charge capacitor 4 to the inherent resistance of the switching element 3 . The second matching circuit 6 functions to adapt the impedance between the switching element 3 and the laser diode 2 . As a result of dimensioning the first matching circuit 5 in this way, only one current or voltage wave is generated and propagates from the charge capacitor 4 in the direction of the switching element 3 when the switching element 3 is operated, meaning it closes following the triggering by an external signal. The impedance matching achieved with the first matching circuit 5 thus prevents the current or voltage wave from being reflected back from the switching element 3 to the charge capacitor 4 . The second matching circuit 6 functions to allow the current and voltage wave, which leaves the circuit element 3 , to travel without reflection to the laser diode 2 . In general, the influences of parasitic inductances can be systematically compensated with the aid of the matching circuits 5 , 6 , thereby making it possible to eliminate or for the most part suppress current and voltage waves that travel back and forth between the components of the circuit arrangement 1 . Since the parasitic inductances are taken into consideration for dimensioning the matching circuits 5 , 6 , their influence can be compensated even if the components are encased transistors or if laser diodes 2 are used, for which the feed line inductances are extremely high. The matching circuit 5 , 6 according to the invention thus simulates a transmission line with defined wave resistance in the circuit arrangement 1 . This not only results in a considerable shortening of the rise times for the current pulses i(t) generated in the circuit arrangement 1 , but it also leads to avoiding undershoots and overshoots during the decay of the current pulse i(t). FIG. 6 c shows the typical time histories for the current pulses i(t), generated in the circuit arrangement 1 according to FIG. 4 and/or FIG. 5 , and thus also the light pulses p(t) generated in the laser diode 2 . The comparison to FIG. 3 shows that the matching circuits 5 , 6 according to the invention consequently exhibit a considerable improvement in the signal curves for the current pulses i(t) and therefore also the light pulses p(t). FIGS. 6 a, b show different current-path simulations for the circuit arrangement 1 according to FIG. 5 . FIG. 6 a illustrates a simulation of the circuit arrangement 1 as shown in FIG. 5 , wherein I and II represent the time histories of the partial current flows through the resistance R 3 and the capacitor C 3 of the RC element R 3 C 3 . The total current flow through the RC element R 3 C 3 is furthermore shown in FIG. 6 a with III, that is to say the total simulated current flow through the laser diode 2 . The measured current flow through the laser diode 2 is shown with IV. The simulation results illustrated in FIG. 6 a show that with a suitable dimensioning of the components R 3 and C 3 of the RC element R 3 C 3 , the time history for the total current flow can be specified precisely. The two partial current flows through R 3 and C 3 add up to a steep rising edge for the total current flow while undershoots in the current flowing through R 3 , which are caused by inductive components, are compensated by overshoots in the current flowing through C 3 . The amplitudes and zero passages of the partial current flows in this case can be adjusted optimally through a careful selection of R 3 and C 3 . FIG. 6 b shows an expanded simulation which, in addition to the current flows I, II through R 3 and C 3 , also takes into account the time constants R 2 C 2 and R 4 C 4 with V and VI as additional compensation elements in the circuit arrangement according to FIG. 5 , so as to generate the total current III which flows through the laser diode 2 . By adding these additional compensation elements, the rise time and pulse shape of the total current flow through the laser diode can be further improved as compared to the simulation in FIG. 6 a , without resulting in a worsening of the post-oscillation behavior. FIG. 7 contains an additional exemplary embodiment of the circuit arrangement 1 according to the invention. Coinciding with the exemplary embodiment according to FIG. 5 , the circuit arrangement 1 according to FIG. 7 again comprises a laser diode 2 functioning as electro-optical converter and an avalanche transistor functioning as switching element 3 . The supply voltage U B is again conducted via the resistance 7 to the charge store. However, the charge store for the present case comprises a multiple-unit arrangement of charge capacitors 4 , wherein these charge capacitors 4 are integrated into the first matching circuit 5 . Coinciding with the exemplary embodiment according to FIG. 5 , the second matching circuit 6 forms a separate circuit between the switching elements 3 and the laser diode 2 . The matching circuits 5 , 6 in turn function to compensate the interfering influences caused by parasitic inductances 8 b - 8 d , meaning the matching circuits 5 , 6 prevent the current and voltage waves from traveling back and forth between the charge store and the switching element 3 as well as the switching element 3 and the laser diode 2 . For the embodiment shown in FIG. 7 , a total of five charge capacitors 4 are provided for the first matching circuit 5 , wherein these are separated by inductances 9 a , 9 b , 9 c and 9 d . Additional charge capacitors that are separated by corresponding inductances may advantageously be provided as part of the arrangement of the first three charge capacitors 4 which are separated by the inductances 9 a , 9 b . The last two charge capacitors 4 are incorporated into a network which comprises the resistances 10 a , 10 b and 10 c as further components. The first three capacitors 4 and the last two capacitors 4 may be separated by a resistance 10 a′. The second matching circuit 6 comprises a capacitor 11 , an inductance 12 , as well as three resistances 13 , 14 , 15 . In addition, the matching circuit 6 in the circuit arrangement 1 functions to simulate a transmission line with defined wave resistance and defined limit frequency to prevent the reflection of current and voltage waves within the circuit arrangement 1 . This embodiment of the circuit arrangement 1 consequently also provides a characteristic for the current pulses i(t) and the light pulses p(t) which corresponds to FIG. 6 c . Whereas the embodiment of the matching circuit 5 , 6 as shown in FIG. 5 has a particularly simple layout with respect to the HF circuitry, owing to the use of RC elements, the matching circuits 5 , 6 shown in FIG. 7 permit a particularly broad adaptation to the parasitic inductances 8 b , 8 c and 8 d . A minimum rise time with simultaneous control of the pulse duration and the decay time can thus be achieved for specific embodiments of the laser diode 2 and/or the switching element 3 . The circuit arrangements 1 shown in FIGS. 4 , 5 and 7 can advantageously be used as transmitting units in optical sensors, wherein these are in particular distance sensors operating based on the light-transit time method. The sensors are furthermore provided with a receiver for receiving light pulses and an evaluation unit in which the distances to detected objects are determined in dependence on the signals received at the receiver. With a distance sensor of this type, the laser diode 2 of the transmitting unit emits sequences of light pulses with a predetermined pulse-pause ratio, wherein the light pulses p(t) have extremely short rise times, typically below one nanosecond, and pulse durations of approximately one nanosecond as a result of using the matching circuits 5 , 6 . For the distance determination, the transit time of a light pulse from the distance sensor to an object and back to the distance sensor is evaluated in each case. In the simplest case, the distance sensor emits light pulses in a fixedly predetermined direction. The distance sensor can furthermore also be embodied as a scanning sensor, for which the emitted light is periodically deflected within a flat or three-dimensional area to be monitored. It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

A circuit arrangement for generating light pulses includes an electro-optical converter; a switching element; and a charge store. The electro-optical converter is connected to the charge store via the switching element. The closing of the switching element triggers a discharging process in the charge store and, in the process, generates an electrical pulse that is converted to a light pulse in the electro-optical converter. First and second impedance matching circuits are arranged, respectively, between the charge store and the switching element and between the switching element and the electro-optical converter.

FIELD OF THE INVENTION The invention concerns a method and an apparatus for making a head on an elongate blank, wherein a blank is moved into a die having a bottom stop such that part of the blank extends outside the die end opposite the bottom stop. The protruding part of the blank is then formed by a pre-upsetter which has a pre-upsetting bushing positioned in extension of the die, and a punch capable of being displaced in the pre-upsetting bushing, said pre-upsetter and said die being moved away from each other during part of the forming procedure. BACKGROUND OF THE INVENTION For pre-upsetting of a head on an elongate blank it is known to place a wire blank in a die having a bottom stop, e.g. in the form of an ejector pin, following which the blank is formed by means of a punch in a pre-upsetter. To obtain optimum quality of the head and to avoid deflection of the blank during the upsetting process, it is of decisive importance that the free length of the wire blank between the die and the pre-upsetter is sufficiently small. Since, however, a large volume in the head is frequently desired, this distance is usually increased to the maximum length. It is frequently desired at the same time that pre-upsetting proceeds to a great diameter, which increases the load on the pre-upsetter pin. These circumstances limit the maximum upsetting ratio that can be achieved, said upsetting ratio being the length of the wire outside the retention of the die divided by the wire diameter. It is desirable to achieve an upsetting ratio as great as possible. It is known to improve the upsetting ratio by allowing the pre-upsetter to move away from the die during the process. This results in the short distance at the start of the process, while the length is increased with a simultaneous corresponding increase of the diameter during the process, whereby the blank remains stable. This takes place in the prior art by spring loading the pre-upsetter so that it is pressed away from the die as the head is formed. This prior art is mentioned e.g. by Billigmann/Feldmann: "Stauchen und Pressen", 1973. However, this process has the drawback that it is difficult to optimize the process, because the movement of the pre-upsetter away from the die is only controlled by a spring, and this restricts the size of upsetting ratios that can be achieved. In this prior art, the punch follows the forced movement of the forming mechanism from e.g. a crank mechanism. SUMMARY OF THE INVENTION The object of the invention is to provide a method and an apparatus making it possible to obtain considerably greater upsetting ratios than has been possible till now. Where the maximum upsetting ratio achievable in the past was about 5, it has been found possible to achieve a considerably higher upsetting ratio with the invention. This is achieved in that the movement of both the punch and the pre-upsetter with respect to the die is positively controlled so that the pre-upsetter and the die are moved away from each other at the end of the forming procedure, while the punch continues to press in a direction toward the die. When the movement of the individual parts with respect to each other is positively controlled in this manner, it is possible to optimize the upsetting process much better than has been possible till now. In one embodiment of the invention, the punch movement is controlled by a cam disc having pre-calculated curve paths. These curve paths are calculated precisely so that the upsetting process will be optimum, because the movement of the punch does not follow the movement of the forming mechanism. An apparatus for performing the method comprises means which can positively control the movement of the punch as well as the pre-upsetter with respect to the die, so that the pre-upsetter is moved away from the die at the end of the working procedure, while the punch continues to press in a direction toward the die. A particular embodiment of the apparatus comprises a cam disc having pre-calculated curve paths for controlling the movement of the punch. In a further the embodiment of the invention, the pre-upsetter is retained with respect to the base of the apparatus, and it is thus the punch and the die which are moved with respect to the pre-upsetter. This provides the advantage that the pre-upsetter may be a bushing which is also used as a cropping bushing in the production of the employed blanks from a wire, and the further advantage that also the other tools used in later process steps may be stationary with respect to the base of the apparatus. When the bottom stop of the die is also movable, the blank can be subjected to pressure from both ends at the same time, enabling better control of the forming of the material. The mentioned movements can be provided either by the provision of separate motors for each of the movements, or by a common motor which produces drives the various movements via various transmissions. BRIEF DESCRIPTION OF THE DRAWING FIGURES The invention will be described more fully below with reference to the drawing, in which FIG. 1 is a perspective view of a screw machine, FIG. 2 is a sectional view of a cropping mechanism, FIG. 3 is a perspective view of a cropping mechanism, FIG. 4 shows the pre-upsetting process, FIG. 5 shows an alternative pre-upsetting process, FIG. 6 shows curve control of a pre-upsetting pin, FIG. 7 shows an embodiment of the control from FIG. 6, FIG. 8 shows an alternative embodiment of the control in FIG. 6, FIG. 9 shows the second pre-forming of a screw head, FIG. 10 shows forming of a slot in a screw head, FIG. 11 shows the making of a screw point, FIG. 12 shows the ejection of a blank from a die with a short ejector pin, FIG. 13 shows the ejection of a blank from a die with a long ejector pin, FIG. 14 shows the use of a slot detector, FIG. 15 shows the making of a holding flange, FIG. 16 shows a mechanism which converts a rotary movement to a reciprocating movement, FIG. 17 shows an alternative embodiment of the mechanism from FIG. 16, FIG. 18 is a sketch of a crank and a connection rod, FIG. 19 are curves showing motion and speed of a crank mechanism, FIGS. 20A-20D shows how the die table can be controlled by a curve path, FIG. 21 shows motion and speed of the die table and bottom stop without transition periods, FIG. 22 corresponds to FIG. 21, but with inserted transition periods, FIG. 23 corresponds to FIG. 22, but without a dwell period, FIG. 24 shows the mounting of a die in a die table, FIG. 25 is a section through a die table with a die, and FIG. 26 shows how a die table can be constructed. DETAILED DESCRIPTION FIG. 1 shows an example of a screw machine in which the invention may be used. The machine is mounted on a base plate 1 and generally consists of three main parts, viz. a tool table 2, a forming mechanism 3 and a crank mechanism 4. The machine is driven by a motor 5 which is mounted on the base plate 1. The starting material for the making of screw blanks is a cold drawn wire 6, which is provided with a lubricating film on the surface originating from the drawing of the wire. The wire is drawn by means of two draw rollers 7, 8 having grooves corresponding to the employed wire diameter through a straightening device 9, which consists of a plurality of straightening units 10, 11, 12, each of which being in turn provided with a plurality of rollers 13. The draw rollers 7, 8 move a given length of wire forwardly through a stationary cropping bushing 14 and into a movable cropping bushing mounted in a rotatable cropping table 15. In a cropping process, which will be described more fully below, a wire blank is separated from the wire 6. As will likewise be described more fully below, the wire blank is then moved into a die 16 which is mounted in a rotatable die table 17. The die table here has five dies and can rotate between five positions. It is moreover axially movable. In a specific position of the die table 17, e.g. a movable cropping bushing in the cropping table 15 will be present opposite the die 16. Correspondingly, tools will be mounted on the tool table opposite others of the dies of the die table, said tools, in cooperation with the dies, being capable of forming the screw blanks arranged in the dies. Forming takes place in that the die table 17 is moved axially toward the tools in a working stroke. The die table 17 is then withdrawn again, and it can rotate to the next position, following which the process is repeated. The rotating movement of the die table 17 can be established by a motor 18 adapted for the purpose. Its axial movement is provided from the crank mechanism 4 and is driven by the previously mentioned motor 5. Power transmission from the motor 5 to the crank mechanism 4 takes place by means of a pulley 19 and a belt 20. By means of two pulleys 21, 22 which are connected to a motor (not shown), the entire tool table 2 can be moved in a direction away from or toward the die table 17, the tool table 2 being guided by a slide bar 23 on the under side of the tool table and a corresponding one (not visible in the figure) on the upper side. The tool table 2 can hereby be adjusted to its correct position, and it is also possible to draw the tool table away from the die table 17 in case of e.g. replacement of tools or die table. The individual parts or processes in the machine will be described more fully below. It is shown in FIGS. 2 and 3 how cropping and pre-upsetting take place. FIG. 2 is a cross-section of the constituent parts, while FIG. 3 is a perspective view. The wire 6 is moved forwardly through the stationary cropping bushing 14 and into a movable cropping bushing 24 which, as mentioned before, is mounted in a rotatable cropping table 15. The cropping table 15 has a plurality of movable cropping bushings 24, 25. When the wire 6 has been moved forwardly to the correct length, the rotatable cropping table 15 is rotated, causing a wire blank to be separated from the wire 6. Further rotation of the cropping table 15 moves the movable cropping bushing forwardly to a position opposite a die 16, here shown at the cropping bushing 25. The released wire blank is here designated 26. When the movable cropping bushing has been placed in this position, a punch 27 is moved forwardly toward the bushing and thereby pushes the blank 26 out of the movable cropping bushing 25 and into a die 16. This movement continues until the blank 26 hits a bottom stop 28, which is positioned at the opposite end of the die 16. However, the punch 27 continues its movement, whereby the blank 26 is pre-upset or pre-formed in the cavity between the die 16 and the movable cropping bushing 25. The punch 27 thus also serves as a pre-upsetting pin and the movable cropping bushing as a pre-upsetting bushing. As described, so-called closed cropping is thus used here, the stationary cropping bushing as well as the movable cropping bushing 24 having a hole corresponding to the diameter of the wire. In traditional presses or screw machines so-called open cropping is frequently used, comprising a stationary cropping bushing with a hole, whereas the movable bushing is open so that the wire blank is supported only in the direction of travel. The closed cropping used here results in optimum quality of the separated blank. Since the quality of the finished object depends upon the quality of all the constituent processes, a higher quality of the separated wire blanks thus also means a higher quality of the finished objects. The figures show two movable cropping bushings 24, 25 which are so arranged in the rotatable cropping table 15 that one is present opposite the die 16 when the other is present opposite the stationary cropping bushing 14. However, more cropping bushings may advantageously be mounted in the cropping table 15. This will give a smaller angle of rotation at each separation. Thus, if e.g. four movable cropping bushings are used, the cut wire blank will reach a position opposite the punch or the pre-upsetting pin 27 and die 16 after two angular rotations of the rotatable cropping table 15. It is shown more clearly in FIG. 4 how the pre-upsetting process proceeds. As described before, the die 16, which is mounted in the die table 17, is moved together with the associated bottom stop 28 in the axial direction of the die. On the other hand, the movable cropping bushing 25 cannot be moved in the axial direction. FIG. 4A shows the situation precisely at the time when pre-upsetting is initiated. The pre-upsetting pin 27 pushes the wire blank 26 out of the bushing 25 and into the die 16 such that the blank 26 reaches the bottom stop 28 immediately before the die 16 at its turning point is in contact with the pre-upsetting bushing 25. An expansion or countersink 29 of the hole in the pre-upsetting bushing is provided at the end of the bushing 25 facing the die 16. A corresponding expansion or countersink 30 is provided in the die 16. These countersinks define cavities which enable the pre-forming of a head on the wire blank 26. These cavities are shaped so that the free length 1 of the wire blank 26 will be as small as possible with respect to the diameter d of the blank. The pre-upsetting pin 27 is controlled so that pre-upsetting continues after the die 16 has again initiated its movement away from the bushing 25. This gives an increased height of the pre-upset while increasing the diameter of the pre-form, so that the volume of the pre-formed material can be increased without the pre-form becoming unstable, so that the upsetting ratio is not restricted by the process. The upsetting ratio is the head wire length divided by the wire diameter. FIG. 4B shows the situation at the termination of the pre-upsetting process. The pre-formed head now has the height L and the diameter D. In addition to a greater upsetting ratio, this method also results in reduced loads on the pre-upsetting pin. FIG. 5 shows an alternative embodiment, using instead of the bottom stop 28 a movable bottom stop, e.g. in the form of an ejector pin 31 which can be moved with respect to the die 16. It will hereby be possible to control the process even better. For the process shown in FIG. 4 to be optimized, the movement of the pre-upsetting pin 27 must be controlled very precisely with respect to the movement of the die 16. FIG. 6 shows an example of how this can be done. The previously described parts are shown to the right in the figure. It will be seen that the die 16 and the bottom stop 28 are being moved away from the bushing 25, so that a head 32 will be formed on the wire blank, the punch or pre-upsetting pin 27 still pressing in a direction toward the die 16. A roller 33 is provided at the end of the pre-upsetting pin 27 and is in contact with the surface of a cam disc 34. The cam disc 34 rotates about the axis of rotation 35, and the cam disc 34 is constructed such that the desired movement of the pre-upsetting pin 27 is achieved. FIG. 7 shows an example of how the mentioned movements can be provided. The reciprocating movement of the die 16 is here provided by a crank mechanism 36 which is driven by a motor 37 by means of a belt 38. The movement of the pre-upsetting pin 27 is provided by another motor 39 which drives the cam disc 34 via another belt 40, thereby transferring the desired movement via the roller 33 to the pre-upsetting pin 27. Alternatively, as shown in FIG. 8, the two movements can also be controlled by a common motor 41. This motor drives, via a belt 42, the crank mechanism 36 which transfers the movement to the die 16. By means of another belt 43 the same motor drives the cam disc 34 which transfers the movement to the pre-upsetting pin 27 via the roller 33. When the pre-upsetting process, which can also be called first pre-forming here, has been terminated and the die table 17 has been drawn back, the table can be rotated to a new position. In the embodiment of the rotatable die table 17 shown in FIG. 1, where said table comprises five dies 16, the die table will now be rotated 72°, so that a new die is moved forwardly to the position opposite a movable cropping bushing, while the die having Just been present here is moved forwardly to a new position. When the die table 17 is again moved forwardly toward the tool table 2, the process described above will be repeated at the cropping or pre-upsetting bushing, while further shaping of the blanks arranged in the dies will take place at the other die positions. FIG. 9 shows an example of a process which can follow the pre-upsetting process described above. The process shown here is called second pre-forming. FIG. 9A shows the situation at the beginning of this process, while FIG. 9B correspondingly shows the situation immediately after it has been completed. In FIG. 9A a blank is placed in a die 45 which, together with a bottom stop 46, is moved toward a tool 47. The tool 47 is positioned stationarily on the tool table 2, while, as described before, it is the die 45 arranged in the die table 17 which moves toward and then away from the tool 47. When the head on the blank 44 hits the tool 47, it will be formed to the desired shape by a depression 48 in this tool. It is shown in FIG. 9B how the blank 44 has now been formed to the blank 49 shown here. The blank 49 together with the die 45 and the bottom stop 46 are being moved away from the tool 47. FIG. 10 correspondingly shows a forming that may take place at a third die position. In this process a slot or the like is produced in the screw head just formed. The blank 49 is now present in a die 50 which, together with a bottom stop 51, is moved toward a tool 52. The tool 52 is provided with a slot projection 53 which forms a slot in the head of the blank 49. FIG. 10A shows the situation at the start of the process, while FIG. 10B shows the situation at the termination of the process, the numeral 54 designating the blank with the slot now produced. Many types of blanks are moreover to be provided with a so-called point, which may e.g. have the shape of a truncated cone at the end of the blank opposite the head. FIG. 11 shows an example of how such a point can be produced simultaneously with the provision of the slot in the head of the screw. FIG. 11 corresponds to FIG. 10A, there being just used a bottom stop 55 here which is provided with a frustoconical cavity 56 arranged in direct extension of the through hole in the die 50. The head on the blank 49 has been shaped in the previously pre-forming process such that there is an excess of material with respect to the size of the finished head on the screw. When the slot projection 53 hits the head on the blank 49, it presses the excessive material down through the shank of the blank. Thus, flow of material will take place in the entire length of the blank, and the material will be pressed out into the frustoconical depression 56 in the bottom stop 55. It will be appreciated that it is possible to produce many different types of points in this manner, since the depression 56 can be given a shape that corresponds to the desired point type. It may be mentioned in particular that it will be possible to produce a hemispherical point, which required a separate process in the past. This is a simple manner of producing a point, and the flow of material down through the shank of the blank moreover causes the load on the tool 52 to be minimized, while the tolerances of the slot will be smaller. The method can also be applied in the production of screws without points. In that case, the depression 56 is shaped as a cylindrical depression having the same diameter as the hole in the die 50, or a bottom stop with a projection extending into the die may be used, said bottom stop being then merely moved slightly backwards from the die when the slot projection 53 produces the slot in the head of the blank. An interesting aspect of the mentioned flow of material down through the shank of the blank is the part of the flow that takes place at the transition between the head and shank of the blank. The reason is that this flow has been found to strengthen the weak point which, otherwise, is traditionally found in screws at this transition. In case of certain types of points it may be necessary or advantageous to produce the point in two steps. If so, a first depression is shaped in the bottom stop 46 which is used in the second pre-forming of the head of the screw blank. It is described above how a blank can be formed in three die positions. This, however, is merely an example, since the three positions may be used flexibly depending upon the shape of the desired objects, or if necessary, more than three positions may be used for the forming. In the machine shown in FIG. 1 with five dies in the die table 17 and thus correspondingly five positions for each die, the last two positions may be used for ejection of the blank, and this ejection can then take place in two steps. FIG. 12 shows the first step of this ejection and thus corresponds to the fourth die position. A blank 57 placed in a die 58 is visible at the top of the figure, which shows the situation immediately before ejection. A bottom stop 59 with a short ejector pin 60 is being moved toward the die. At the bottom of the figure, the bottom stop 59 with the short ejector pin 60 has reached the die 58, and the ejector pin 60 has loosened the blank 57 and pushed it a short and well-defined distance out of the die 58. Because of the preceding processes the blank 57 will often be very firmly fixed in the hole of the die, and a very great force is therefore required to release the blank and push it out of the die. If the blank should have been pushed out of the die in one operation, this would have required an ejector pin which had the same length as the die, and this would therefore involve a very great risk of pin bending or breaking. Since the short ejector pin 60 can release the object with a great force without any risk of deflection, release of the blank from the die need not be facilitated by means of lubrication or the like. FIG. 13 shows how the blank 57 is then ejected completely from the die 58 at the fifth and last die position. This takes place in that a bottom stop 61 with a long ejector pin 62 pushes the blank out of the die. The ejector pin 62 has approximately the same length as the die 58 and thus as the blank 57. The top of the figure shows the bottom stop 61 and the long ejector pin 62 on their way toward the die 58, and at the bottom of the figure the bottom stop 61 and the ejector pin 62 have pushed the blank 57 completely out of the die 58. Since the blank 57 having been released in the preceding die position by means of the short ejector pin 60, is now positioned relatively loosely in the die, only a modest force is required to eject the blank completely, and the long ejector pin 62 will therefore not tend to break or bend. Both the short ejector pin 60 and the long ejector pin 62 may have the same diameter as the shank of the blank 57, since an optional point on the blank 57, as described before and shown in FIG. 11, will be produced by means of a depression in the corresponding bottom stop 55. In the past, it was necessary to produce such a point by making a constriction in the die itself, and an ejector pin could only have a diameter corresponding to the narrowest portion of the die. Since, as shown in FIG. 12, the short ejector pin 60 pushes the blank 57 a short and well-defined distance out of the die, this may be utilized for controlling the blank produced. FIG. 14 shows an example of how this may be done. The figure corresponds to FIG. 12, but includes a slot detector 63 comprising a control bit 64 which is arranged at a carefully determined distance from the die 58. The slot detector 63 is connected via a connection wire 65 to electronic equipment capable of processing the signals emitted from the slot detector 63. It is shown at the bottom of the figure how the short ejector pin 60 has pushed the blank 57 out of the die 58, and that the blank contacts the control bit 64. If the slot projection 53, by means of which the slot in the screw was made, has e.g. been damaged, the slot may be too small, and the blank 57 will then exert a pressure against the control bit 64. This is registered by the slot detector 63 which transmits signals about this to a control unit via the connecting wire 65. Thus, in this manner it is possible to control the geometry of the produced blanks. Since the blank has been pushed out of the die, it is also possible to control e.g. the height or diameter of the head in addition to a possible slot. Furthermore, the distance between the die and the tool table may be detected, and the signals from the detector 63 may be used for adjusting the tools. When the machine starts from a cold state, the machine parts will be heated owing to the processes in the machine and these parts will be thermally expanded at the same time. It may therefore be an advantage that these expansions can be allowed for by adjusting the position of the tools with respect to the dies in the die table 17. This can be done since, as mentioned before and shown in FIG. 1, it is possible to displace the entire tool table 2, and when such a displacement is effected in response to the control signals from the detector 63, a more uniform quality will be obtained which is not dependent on thermal heating in the machine. The shown slot detector is just one of the many available possibilities of making a control measurement of the blanks produced. Measurements of other geometrical properties of the produced objects can be made, and it is also conceivable to make the measurement in other ways. Thus, e.g. a measurement may be made by means of laser beams so that the detector need not be in contact with the produced objects. When e.g. a slot is made in a head on a blank, as described above and shown in FIG. 10, there is a certain risk that the slot tool unintentionally pulls the blank out of the die. This can be counteracted as shown in FIG. 15. Here, a blank 66 positioned in a die 67 and a bottom stop 68 are visible. The blank has a head 69 at one end, and it will be seen that a small holding flange 70 is provided at the opposite end of the blank. The flange is provided in that the die 67 at this end has a small expansion of the through hole. The pre-upsetting process, which has been described and is shown in FIG. 4, also causes material to be pressed out into this expansion, thereby making the flange 70. However, the flange does not necessarily extend all the way round the blank, since a smaller projection on the blank will be sufficient to perform the desired function, viz. to protect the blank against being pulled out of the die at an unappropriate time. The flange or the projections are just large enough to prevent this and also small enough for an ejector pin, in the subsequent ejection of the blank, to be able to deform the flange or the projections and eject the blank from the die. It is shown in FIG. 16 how the reciprocating movement of the die table 17 and the associated bottom stops can be established. As described before and shown in FIG. 1, this axial movement is provided by a motor 5, and the power transmission from the motor 5 takes place via belts 19, 20 and a crank mechanism 4. FIG. 16 shows in greater detail how this mechanism is constructed. A crank 71 rotates about its axis of rotation 72 and is driven by the belt 20, as mentioned. A connecting rod 73 is secured to the crank 71 at one end and to a holder 74 at the other. When the crank 71 rotates, the rotating movement is converted via the connecting rod 73 to a reciprocating movement of the holder 74. The holder 74 is connected with two wedges 77, 78 via two rods 75, 76 such that these wedges, too, can be reciprocated. For this reciprocating movement to take place with a very small friction, a plurality of rollers 81 and 82, respectively, are positioned between the wedges 77, 78 and guide rails 79, 80. A bearing block 83 is interposed between the two wedges 77, 78, which is capable of being moved in a direction transversely to the direction of travel of the wedges. This movement, too, can take place with a very small friction, because rollers 84 and 85, respectively, are arranged between the bearing block and the guide rails 86, 87. Finally, a plurality of rollers 88 are also provided between the bearing block and the wedge 77 as well as a plurality of rollers 89 between the bearing block 83 and the wedge 78. When the wedges 77, 78 are moved to the left in the figure, the bearing block 83 will be moved in a downward direction in the figure because it can only move in the transverse direction. When similarly the wedges are moved to the right, the bearing block 83 will be moved upwardly. The bearing block 83 thus moves to and fro in a direction transversely to the corresponding movement of the wedges. It will be seen that the wedge angle selected in the figure will cause the movement of the bearing block to be smaller than that of the wedges. The bearing block 83 is connected via connections (not shown) with the die table 17 and the associated bottom stops, respectively. In this manner the die table 17 can perform a relatively short reciprocating movement, it being simultaneously possible to exert great forces which are necessary in the forming of the blanks positioned in the dies. Because of the wedge angle shown in the figure the wedges and thereby the crank mechanism will perform a greater movement, but then a smaller force is required, and the crank mechanism can therefore be dimensioned smaller than would otherwise be necessary. The rollers 81, 82, 84, 85, 88 and 89 shown in FIG. 16, which serve to reduce the friction between the individual components, may also have other shapes. Thus, e.g. balls may be used instead. An alternative embodiment is shown in FIG. 17 in which slide guides are used instead. The slide guides 90, 91 reduce the friction between the wedges 77, 78 and the guide rails 79, 80, while the slide guides 92, 93 correspondingly reduce the friction between the bearing block 83 and the guide rails 86, 87. Finally, the slide guides 94, 95 serve to reduce the friction between the bearing block 83 and the wedges 77, 78. It is of great importance that the production rate of a machine of the type described here can be as high as possible. At the same time, the speed of the die at the beginning of the actual forming should be as low as possible. This is achieved i.a. by using a wedge mechanism, as described above, the wedge angle being selected such that the movement of the bearing block and thereby of the die table has a relatively small length of stroke. Furthermore, the velocity at which the die table approaches its extreme positions in such a movement differs. This is shown in FIGS. 18 and 19. FIG. 18 schematically shows a crank mechanism. The crank rotates about an axis of rotation C. At its one end a connecting rod of the length a is secured to the crank at a distance r from its center or axis of rotation. Rotation of the crank causes the point P, which designates the other end of the connecting rod, to perform a reciprocating movement on the horizontal line. 1 designates the distance from the axis of rotation C to the point P. The distance 1 is shown at the top of FIG. 19 as the function of time at a constant crank speed of rotation. If the length a is very great with respect to the distance r, the point P will perform a pure sine movement, which is shown with the first of the two curves. If, on the other hand, the length a is short with respect to the distance r, the sine curve will be distorted. The smaller a is with respect to r, the more pronounced the distortion is. In the extreme case where a is equal to r, the point P will lie still for half of a period of rotation. The other curve at the top of FIG. 19 shows the movement of the point P in the situation where a is equal to 1.2 times r. It will be seen that the point P relatively slowly approaches the extreme position which is passed at the time t1, while, on the other hand, it relatively quickly approaches the other extreme position, as shown at t0 or t2. The bottom of FIG. 19 correspondingly shows the speed of the point P as a function of time for the same two situations. It is even more clearly visible from this that the point P approaches one extreme position at a relatively low speed and the other extreme position at a relatively high speed. To achieve the lowest possible working rate for a given production rate, the die table is therefore connected with the bearing block 83 such that forming of the blanks mounted in the dies takes place at that one of the extreme positions of the die table where it approaches the position at the lowest speed. As described before, the die table 17 and the associated bottom stops are moved as a common unit towards the tools at the forming moment and then away from these again. However, at the opposite extreme position the die table must be separated from the bottom stops for the die table to rotate to a new position. This can be done by mounting a stop means which prevents the die table from following the bottom stops to their extreme position. This, however, will give rise to generation of much noise and great wear on the die table, partly when the die table hits the stop means, and partly when the bottom stops again hit the die table on their way back. This problem can be remedied by inserting transition periods where the die table is slowed down before hitting the stop means and is accelerated before being hit by the bottom stops. It is shown in FIGS. 20A-20D how this can be done through the aid of a cam means 96. In FIG. 20A the die table 17 is shown in the extreme position in which it is in contact with the tools, here e.g. the tool 98. As will be seen from the figure, a bottom stop 97 is in contact with the die table 17 at its opposite end. The cam means 96 is provided with a curve path 100, and it is moved in a direction transversely to the axial direction of travel of the die table. It is shown by arrows in the figure that the die table 17, after the contact with the tool 98, is moved away from it in the direction of the arrow while the cam means 96 is moved in an upward direction. As will be seen from the figure, the cam means 96 is provided with a curve path 100, while a roller 99 is mounted on the die table 17. FIG. 20B shows the situation where the die table 17 together with the bottom stop 97 has been moved away from the tool 98 and is about to hit the cam means 96, which continues its upwardly directed movement. In FIG. 20C, the roller 99 has contacted the curve path 100. The curve path 100 is shaped such that together with the speed of the cam means 96 it entails that the die 17, immediately after contact between the roller 99 and the curve path 100, will continue at an unchanged velocity and is then slowly braked. It will be seen from the figure that the bottom stop 97 continues its movement and is therefore no longer in contact with the die table 17. FIG. 20D shows the situation in the extreme position where both the die table 17 and the bottom stop 97 are removed from the tools. The die table 17 is now separated from the bottom stop 97 and can rotate to a new position. Then the process proceeds in the opposite direction. The bottom stop 97 is moved forwardly toward the die table 17, which is simultaneously accelerated because of the cooperation between the curve path 100 and the roller 99, the cam means 96 now moving in a downwardly extending direction. Owing to the shape of the curve path 100 the die table 17, when being hit by the bottom stop 97, will have attained precisely the speed which the bottom stop has at this moment. FIGS. 21, 22 and 23 show the movement and the speed of the die table 17 and the bottom stop 97, respectively, in three different situations. The tops of the figures show the movement expressed by the distance A from the tools. The movement of the bottom stop 97 is shown in thin line, while the movement of the die table 17 is shown in thick line. The bottoms of the figures correspondingly show the velocity (V) of the bottom stop in thin line and of the die table in thick line. FIG. 21 shows the situation where there is no transition period, so that the die table 17 merely hits a stop means on its way away from the tools and is then hit by the bottom stop on its way toward the tools. The movement of the bottom stop is here shown as a pure sine curve. As mentioned above, this will be the case only if a connecting rod having a very long length with respect to the size of the crank is used. The correct curve will be distorted as shown in FIG. 19. It will be seen that for half a period the die table will be present in a dwell position where it can be rotated, while the bottom stop continues with a harmonic movement to its extreme position and then returns. In FIG. 22, transition periods are inserted between the working period where the die table 17 moves together with the bottom stop 97 and the dwell period where the die table stands still. FIG. 23 shows a situation where the transition periods have been made very long so that the dwell period is short or zero. This has the advantage that also the die table 17 performs a harmonic movement and is therefore subjected to the lowest possible forces in the axial direction because of the movement. FIG. 24 shows a section of a die table 101 in which a die 102 is mounted. A band winding 103 is applied around the die 102. This band winding has been provided by winding a steel band around a cylindrical core, which may either be the die 102 itself, which is made of hard metal, or a cylindrical insert. The band winding 103 biasses the die 102 by absorbing the outwardly directed forces which occur when the die 102 is subjected to strong compressive stresses in the axial direction. FIG. 25 shows a section through part of the die table 101, and it is shown more clearly in this section how the die 102 may be mounted in the die table 101. The die 102 here has a conical shape and is mounted in a bushing 104, whose interior has a conical shape corresponding to that of the die. The bushing 104 is wound with the band winding 103, which is in turn placed in a suitable hole in the die table 101. This structure has the advantage that the die 102, because of the conical shape, can easily be replaced by pressing it out of the bushing 104. A new die can be pressed down into the conical bushing 104 and thus ensure that the die is biassed correctly. The advantage of biassing the hard metal die in this manner by means of a band winding is that the die unit, including bias, can be given a very small cross-sectional area. This means that the dies in a die table can be positioned more closely to the axis of rotation of the die table and thus contribute to reducing its moment of inertia. FIG. 26 shows an example of the shape of a die table 101. In this case the die table has five dies, all of which are biassed by means of band windings as described above. For a high production rate to be achieved, the die table must have as low a moment of inertia as possible. This is achieved partly in that the dies, including bias by means of band windings, have a modest extent, and partly because they can then be positioned more closely to the axis of rotation 105 of the die table. The moment of inertia of the die table is then additionally diminished by a recess 106 between each die, such that the die table has the shape of a clover leaf. This contributes to reducing the moment of inertia of the die table considerably, because precisely that portion of the material is removed which is most remote from the axis of rotation 105 and thereby contributes most to the moment of inertia. Further, it also contributes to reducing the moment of inertia that dies having the same length as the blanks are used here. The known machines usually employ longer and thus heavier dies. The small moment of inertia entails that the die table can be driven directly by a servomotor having a high production rate. The foregoing description gives examples of how a machine according to the invention can be constructed, and it will be appreciated that details in the described and shown matter can be modified in many ways within the scope of the invention.

In a method of making a head on an elongate blank (26), the blank (26) is moved into a die (16) having a bottom stop (28) such that part of the blank (26) extends outside the die (16) end opposite the bottom stop (28). The protruding part of the blank (26) is engaged by a pre-upsetting bushing (25) positioned in extension of the die (16) and a punch (27) is slidably movable in the pre-upsetting bushing. The bushing (25) and the die (16) are moved away from each other during the latter part of the deforming procedure. The movement of both the punch (27) and the bushing (25) with respect to the die (16) is positively controlled so that the bushing (25) and the die (16) are moved away from each other at the latter part of the deforming procedure, while the punch (27) continues to press against the blank in a direction toward the die (16).

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/081,967, filed on Jul. 18, 2008, which is incorporated herein by reference in its entirety. This application is related to U.S. patent application Ser. No. 12/505,195, filed on Jul. 17, 2009, entitled “METHODS AND SYSTEMS FOR DNA ISOLATION ON A MICROFLUIDIC DEVICE,” and naming Michele R. Stone as the inventor, which application is incorporated herein by reference in its entirety. BACKGROUND 1. Field of the Invention The present invention relates to methods and systems for microfluidic DNA sample preparation. More specifically, embodiments of the present invention relate to methods and systems for the isolation of DNA from patient samples on a microfluidic device and use of the DNA for downstream processing, such as performing amplification reactions and thermal melt analysis on the microfluidic device. 2. Description of Related Art The detection of nucleic acids is central to medicine, forensic science, industrial processing, crop and animal breeding, and many other fields. The ability to detect disease conditions (e.g., cancer), infectious organisms (e.g., HIV), genetic lineage, genetic markers, and the like, is ubiquitous technology for disease diagnosis and prognosis, marker assisted selection, correct identification of crime scene features, the ability to propagate industrial organisms and many other techniques. Determination of the integrity of a nucleic acid of interest can be relevant to the pathology of an infection or cancer. One of the most powerful and basic technologies to detect small quantities of nucleic acids is to replicate some or all of a nucleic acid sequence many times, and then analyze the amplification products. Polymerase chain reaction (PCR) is perhaps the most well-known of a number of different amplification techniques. PCR is one of the more sensitive methods for nucleic acid analysis. However, many substances in clinical samples, including blood, can affect PCR and can result in substantial error in the PCR results. Thus, DNA isolation and purification are critical to methods for DNA analysis. Conventional DNA preparation requires large volume samples and requires a long process time. Microfluidic technology makes it possible to use much less sample and less time for DNA sample preparation. Solid phase extraction methods have been applied in DNA sample preparation. DNA is selectively extracted on the solid phase while other substances in the sample are washed out of the extraction column. For instance, Breadmore et al. ( Anal Chem 75(8): 1880-1886, 2003) reported on a microchip-based DNA purification method using silica beads packed into glass microchips and immobilized within a sol-gel. Alternatively, DNA isolation can be achieved by nuclei size sieving. Since DNA only exists in the nuclei of cells, DNA samples can be prepared by selectively isolating nuclei from the sample. Traditional nuclei isolation is slow and has low efficiency. Generally, nuclei isolation is performed by selective lysis of cellular membranes while keeping the nuclei intact. Nuclei are then isolated by centrifuge, sediment or sieving. Dignani et al. ( Nucl Acids Res 11: 1475-1489, 1983) reported isolation of nuclei from samples by centrifugation. U.S. Pat. No. 5,447,864 discloses a method of isolating nuclei using a DNA mesh. U.S. Pat. No. 6,852,851 discloses a method of isolating nuclei in a microfabricated apparatus that contains a plurality of radially dispersed micro-channels. U.S. Pat. No. 6,992,181 describes the use of a CD device for the purification of DNA or cell nuclei. This method requires moving parts and centrifugal force to isolate DNA and or cell nuclei, using a barrier in the channel to impede flow of DNA and nuclei. Palaniappan et al. ( Anal Chem 76:6247-6253, 2004) reported a continuous flow microfluidic device for rapid erythrocyte lysis. VanDelinder et al. ( Anal Chem 78:3765-3771, 2006) reported a separation of plasma from whole human blood in a continuous cross-flow in a molded microfluidic device. To increase mixing of lysis buffer with blood sample in microfluidic channel, Palaniappan et al. ( Anal Chem 78:5453-5461, 2006) reported a microfluidic channel with the channel floors that are patterned with double herringbone microridges. VanDelinder et al. ( Anal Chem 79:2023-2030, 2007) describe a perfusion in microfluidic cross-flow for particles and cells. Particles flow in the main channel while a perfusion flows through the side channels to exchange the medium of suspension. There are several problems with current technology of purifying DNA by isolating nuclei from cells. First, the conventional approach is slow. Usually, the conventional approach takes hours to finish from cell lysis to the nuclei isolation. For example, the purification process described in U.S. Pat. No. 6,852,851 is carried out in a plurality of micro channels with a mesh built into the micro channel. However, because the size of micro channels is limited, the process can treat only limited sample sizes from 100 nl to 1 μl. Another problem is with the method of releasing DNA and/or nuclei from membrane. For example, DNAse is used in U.S. Pat. No. 5,447,864 to release nuclei from membrane. However, the addition of DNAse will fail the down stream process. In U.S. Pat. No. 5,447,864, sodium dodecyl sulfate solution or proteinase K is used to disrupt the nuclear envelope in order to release DNA. However, these lysis reagents will also seriously inhibit the downstream process. The conventional nuclear lysis method is to use high concentration sodium chloride (0.5 M) to disrupt the nuclear membrane. However, the high concentration sodium chloride will also inhibit the downstream process. In addition, the current technologies require specific buffers for DNA binding and washing, most of which are not compatible with down stream applications such as PCR. These technologies also have a wide range of efficiencies in the overall quantity of DNA that is purified. This can be a significant problem when samples are to be used in microfluidics. The multiple reagents that are typically required for DNA purification would demand that moving parts, such as valves, be constructed into a microfluidic device for the introduction of multiple reagents in a solid phase extraction. In a microfluidic system, solid phase extraction or the use of multiple reagents is complicated and can lead to system failures. Although the various methods exist to capture nuclei for use in down stream application or to separate specific cells from a sample population, none of these methods describes a single device that is capable of extracting cell nuclei and isolating the nucleic acid contained in the cell nucleic that is suitable for microfluidic processing and down stream processes such as amplification reactions and detection analysis. Thus, there is a need to develop microfluidic systems and methods for DNA isolation. SUMMARY OF THE INVENTION The present invention relates to methods and systems for microfluidic DNA sample preparation. More specifically, embodiments of the present invention relate to methods and systems for the isolation of DNA from patient samples on a microfluidic device and use of the DNA for downstream processing, such as performing amplification reactions and thermal melt analysis on the microfluidic device. In one aspect, the present invention provides a method of purifying DNA from a sample (e.g., a patient sample or other sample) in a microfluidic device. According to this aspect, the method comprises: (a) mixing the sample and a lysis buffer in a mixing region of a microfluidic device; (b) selectively lysing the cellular membranes of cells in the sample without lysing the nuclear membranes of cells in a cell lysing region of the microfluidic device to produce intact nuclei from the cells; (c) trapping the intact nuclei from the sample on a membrane in a cell trapping region of the microfluidic device while allowing other components of the sample to flow through the membrane and into a waste collection region of the microfluidic device; (d) lysing the intact nuclei trapped on the membrane; (e) releasing the DNA from the lysed nuclei; and (f) collecting the released DNA in a DNA collection region of the microfluidic device. In some embodiments, the sample is a patient sample which could be, for example, a blood sample, a urine sample, a saliva sample, a sputum sample, a cerebrospinal fluid sample, a body fluid sample or a tissue sample which contain white blood cells. In other embodiments, the patient sample comprises white blood cells. In additional embodiments, the patient sample is first enriched for white blood cells prior to the selective lysis of the cellular membrane. In some embodiments, the enrichment of white blood cells is performed by filtration. In additional embodiments, the enrichment of white blood cells is performed using antibodies. In some embodiments, the antibodies are coupled to a solid phase, such as beads, magnetic beads, particles, polymeric beads, chromatographic resin, filter paper, a membrane or a hydrogel. In some embodiments, the selective lysis is performed by contacting the patient sample, either whole or after white blood cell enrichment, with a buffer (referred to herein as a lysis buffer or nuclei isolation buffer) that selectively permeabilizes cellular membranes while leaving the nuclei of the cells intact. Nuclei isolation buffers that have these characteristics are well known to the skilled artisan. Products that include nuclei isolation buffers for selectively lysing cellular membranes are commercially available. Suitable commercial products that include such buffers, include, but are not limited to, Nuclei EZ Prep Nuclei Isolation Kit (NUC-101) (Sigma, St. Louis, Mo., USA), Nuclear/Cytosol Fractionation Kit (K266-100) (BioVision Research Products, Mountain View, Calif., USA), NE-PER Nuclear and Cytoplasmic Extraction Reagents (Pierce, Rockville, Ill., USA), Nuclear Extraction Kit (Imgenex, Corp., San Diego, Calif., USA), Nuclear Extract Kit (Active Motif, Carlsbad, Calif., USA), and Qproteome Nuclear Protein Kit (Qiagen, Valencia, Calif., USA). See also, U.S. Pat. Nos. 5,447,864, 6,852,851 and 7,262,283. It is known that the type of nuclei in question may determine which nuclei isolation buffer will be required. See, U.S. Pat. No. 5,447,864 for a discussion of factors that can be optimized for preparing a suitable selective lysis buffer for different cell types. In one embodiment, the lysis buffer is a hypotonic buffer. For example, a commercial hypotonic lysis buffer can be purchased from Sigma Aldrich, Nuclei EZ lysis buffer (N 3408). A kit is also available from Sigma Aldrich, Nuclei EZ Prep Nuclei Isolation Kit (Nuc-101). A common recipe for a 10× hypotonic solution is, 100 mM HEPES, pH 7.9, with 15 mM MgCl 2 and 100 mM KCl. In another embodiment, the lysis buffer is a hypotonic buffer that comprises a detergent. Suitable detergents include, but are not limited to ionic detergents, such as lithium lauryl sulfate, sodium deoxycholate, and Chaps, or non-ionic detergents, such as Triton X-100, Tween 20, Np-40, and IGEPAL CA-630. In another embodiment, the lysis buffer is an isotonic buffer. For example, Sigma Aldrich offers a kit, CelLytic Nuclear Extraction kit, which contains an isotonic lysis buffer. A common recipe for a 5× isotonic lysis buffer is, 50 mM Tris HCl, pH 7.5, with 10 mM MgCl 2 , 15 mM CaCl 2 , and 1.5M Sucrose. In an additional embodiment, the buffer is an isotonic buffer that comprises a detergent which may be an ionic detergent or a non-ionic detergent. In other embodiments, the selective lysis is performed using a hypotonic lysis buffer that contains a weak detergent. In further embodiments, the patient sample and the hypotonic lysis buffer are mixed in a 1:1 ratio. In additional embodiments, the selective lysis of the cellular membranes totally lyses red blood cells. In some embodiments, the steps of lysing the intact nuclei trapped on the membrane and releasing the DNA from the lysed nuclei comprise flowing an elution buffer over the intact nuclei trapped on the membrane. In some embodiments, the elution buffer is a buffer in which the DNA is compatible. In other embodiments, elution buffer comprises a Tris buffer, KCl and a zwitterion. In one embodiment, the zwitterion is betaine, trimethylamine-N-oxide, trimethylamine hydrochloride or trimethylamine bromide. In other embodiments, the elution buffer is an amplification reaction buffer that may contain the non-assay specific amplification reagents. In additional embodiments, the amplification reaction buffer is a PCR buffer that may contain the non-assay specific PCR reagents. In further embodiments, the elution buffer contains a dye that binds to DNA. In additional embodiments, the dye is useful for quantifying the amount of DNA in the channel. In additional embodiments, the nuclei are lysed by heat to release the DNA from the nuclei. In some embodiments, the nuclei are subjected to heat prior to an amplification reaction. In other embodiments, the nuclei are subjected to heat during the amplification reaction and the nuclei lysis region is the initial region of microfluidic device in which the amplification reaction is conducted. In some embodiments, the intact nuclei trapped on the membrane are lysed by applying heat to the trapped nuclei. In one embodiment, the trapped nuclei are heated for approximately 1 to 10 minutes at a temperature in the range of approximately 35° C. to 95° C. In another embodiment, the trapped nuclei are heated for approximately 7 minutes at a temperature of approximately 50° C. In a further embodiment, the DNA released from the lysed nuclei flows to the DNA collection region of the microfluidic device by flowing an elution buffer over the DNA. In some embodiments, the elution buffer is as described herein. In another aspect, the present invention provides a microfluidic device for purifying DNA from a patient sample. In accordance with this aspect, the microfluidic device comprises a sample port and lysis buffer port in fluid communication with a mixing region of the microfluidic device. The mixing region is configured to permit mixing of a patient sample from the sample port and lysis buffer from the lysis buffer port. The microfluidic device also comprises a cell lysis region in fluid communication with the mixing region. The cell lysis region is configured to permit the lysis buffer to selectively lyse cellular membranes of cells in the patient sample without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the patient sample. The microfluidic device further comprises a nuclei trapping region wherein intact nuclei from the patient sample are trapped on a membrane while other components of the patient sample flow through the membrane and into a waste collection region of the microfluidic device. The nuclei trapping region is in fluid communication with the cell lysis region. The microfluidic device also comprises a nuclei lysis region in which the nuclear membranes of the intact nuclei are lysed to release the DNA. The microfluidic device further comprises a DNA collection region in the microfluidic device wherein DNA released from the trapped intact nuclei is collected. In some embodiments, the microfluidic device further comprises an elution buffer port in fluid communication with the nuclei trapping region and the nuclei lysing region. The elution buffer from the elution buffer port can be controlled to flow through the nuclei trapping region and the nuclei lysing region to lyse the nuclear membranes of the trapped intact nuclei to release the DNA. In one embodiment, the elution buffer is one in which the DNA is compatible. In other embodiments, elution buffer comprises a Tris buffer, KCl and a zwitterion. In one embodiment, the zwitterion is betaine, trimethylamine-N-oxide, trimethylamine hydrochloride or trimethylamine bromide. In other embodiments, the elution buffer is an amplification reaction buffer that may contain the non-assay specific amplification reagents. In additional embodiments, the amplification reaction buffer is a PCR buffer that may contain the non-assay specific PCR reagents. In some embodiments, the microfluidic device further comprises a heat source which is configured to provide heat to the intact nuclei in the nuclei lysis region sufficient to lyse the nuclear membranes thereby releasing the DNA. In one embodiment, the heat source is controlled to heat the nuclei for approximately 1 to 10 minutes at a temperature in the range of approximately 35° C. to 95° C. In another embodiment, the heat source is controlled to heat the nuclei for approximately 7 minutes at a temperature of approximately 50° C. In some embodiments, the DNA released from the lysed nuclei flows to the DNA collection region of the microfluidic device by flowing an elution buffer over the DNA. In other embodiments, the membrane is made of silicon, glass, polymers, polyester, polycarbonate or nitrocellulose. In additional embodiments, the membrane has a round or rectangular shape. In one embodiment, the membrane has a pore size from approximately 500 nm to 10 μm. In another embodiment, the membrane has a pore size from approximately 0.5 μm to 10 μm. In some embodiments, the microfluidic device comprises multiple layers. In one embodiment, the microfluidic device further comprises: (1) a first layer comprising the lysis buffer port, the patient sample port, an elution buffer port, a purified DNA collection port and a waste port; (2) a second layer comprising a network of microchannels that transports the lysis buffer solution and the patient sample to the mixing region of the microfluidic device; (3) a third layer comprising a network of microchannels; (4) the membrane located between the second and third layers. In some embodiments, the patient sample and the lysis buffer solution mix in the mixing region and flow in the microchannels to the cell lysis region, and wherein the patient sample and the lysis buffer solution flow from the cell lysis region to the membrane in the nuclei trapping region, and wherein the other components of the patient sample flow through the membrane and into a microchannel in the third layer and to the waste collection region of the microfluidic device, and wherein the DNA released from the nuclei flows through the membrane and into a microchannel located in the third layer and to the DNA collection region. In other embodiments, the microfluidic device further comprises: (1) a first layer comprising the lysis buffer port, the patient sample port, an elution buffer port, a purified DNA collection port and a waste port; (2) a second layer comprising a network of microchannels that transports the lysis buffer solution and the patient sample to the mixing region of the microfluidic device; (3) a third layer comprising a hole through which fluid flows from the microchannels in the second layer and onto the membrane; (4) a fourth layer comprising a hole through which fluid flows from the membrane and into microchannels located in a fifth layer, therein the fifth layer further comprising the waste collection region and the DNA collection region. In another aspect, the present invention provides another microfluidic device for purifying DNA from a patient sample. In accordance with this aspect, the microfluidic device comprises a cell lysis region configured such that a lysis buffer is permitted to mix with the patient sample resulting in the selective lysing of cellular membranes of cells in the patient sample without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the patient sample. The microfluidic device also comprises a cross-flow filtration region in which intact nuclei are separated from other components of the patient sample by a filter. The filter has a pore size such that the intact nuclei do not pass through the filter and the other components of the patient sample pass through the filter and are carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region. The microfluidic device further comprises an interface channel in fluid communication with said cross-flow filtration region through which purified nuclei flow for downstream analysis. In some embodiments, the cross-flow filtration region comprises a microfluidic separation channel in fluid communication with the cell lysis region and configured to receive the intact nuclei and the other components of the patient sample from the cell lysis region. The filter is constructed in the microfluidic channel. The cross-flow filtration region also comprises a cross-flow buffer port configured to permit the cross-flow buffer to flow across the microfluidic separation channel and through the filter. The cross-flow buffer, as it flows across the separation channel, facilitates removal of the other contents of the patient sample from the separation channel through the filter. The intact nuclei flow through the separation channel. In some embodiments, the flow of one of the lysed patient sample and the cross-flow buffer is driven by a pressure differential and the flow of the other of the lysed patient sample and cross-flow buffer is driven by an electrophoretic voltage potential. In one embodiment, the pore size of the filter is between approximately 2 μm to 10 μm. In another embodiment, the pore size of the filter is approximately 5 μm. In one embodiment, the filter is a membrane. In another embodiment, the filter is an array of pillars that forms as size exclusion barrier. In some embodiments, the cross-flow filtration region is configured to separate the intact nuclei, bacteria and viruses from the lysed patient sample. In one embodiment, the cross-flow filtration region comprises a first filter to separate the intact nuclei, a second filter to separate bacteria and a third filter to separate viruses. In another embodiment, the first filter is located closest to a cross-flow buffer port, the second filter located next closest to the cross-flow buffer port, and the third filter located furthest from the cross-flow buffer port. In a one embodiment, the pore size of the first filter is between approximately 2 μm to 10 μm, the pore size of the second filter is between approximately 0.2 μm to 2 μm, and the pore size of the third filter is between approximately 10 nm to 400 nm. In another embodiment, wherein the pore size of the first filter is approximately 8 μm, the pore size of the second filter is approximately 0.4 μm, and the pore size of the third filter is approximately 100 nm. In some embodiments, the microfluidic device further comprises more than one cross-flow filtration region in which each cross-flow filtration region receives a portion of the lysed patient sample from the cell lysis region, and each cross-flow filtration region is in fluid communication with one or more interface channels. In one embodiment, the filter of one cross-flow filtration system has a pore size that is different from the pore size of one other cross-flow filtration system. In some embodiments the microfluidic device further comprises a nuclei concentration region in which the intact nuclei from the cross-flow filtration region are concentrated. In one embodiment, the nuclei concentration region comprises a concentration channel having a sample input section, a sample outlet section and a wall portion configured to prevent intact nuclei from flowing through said wall portion and to allow the other contents of the patient sample to flow through said wall portion. In one embodiment, the wall portion is a filter. In another embodiment, the filter comprises a set of pillars placed along the concentration channel. In some embodiments, the patient sample is as described herein. In other embodiments, the patient sample comprises white blood cells. In further embodiments, the downstream analysis comprises an amplification reaction in which nucleic acid is amplified and/or a detection procedure for determining the presence or absence of an amplified product. In another aspect, the present invention provides a microfluidic system for purifying DNA from a patient sample. In accordance with this aspect, the microfluidic system comprises a microfluidic device. The system also comprises a cell lysis region in the microfluidic device configured such that a lysis buffer is permitted to mix with the patient sample resulting in the selective lysing of cellular membranes of cells in the patient sample without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the patient sample. The system further comprises a cross-flow filtration region in the microfluidic device in which intact nuclei are separated from other components of the patient sample by a filter. The filter has a pore size such that the intact nuclei do not pass through the filter and the other components of the patient sample pass through the filter and are carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region. The system also comprises a nuclei lysis region in the microfluidic device in which the nuclear membranes of the intact nuclei are lysed to release the DNA. The nuclei lysis region is in fluid communication with the cross-flow filtration region. The system also comprises an amplification reaction region in the microfluidic device in which the nucleic acid is amplified and a detection region in the microfluidic device for determining the presence or absence of an amplified product. In some embodiments, the nuclei lysis region is part of the amplification reaction region. In other embodiments, the regions are in separate microfluidic devices. In one embodiment, the cell lysis region, the cross-flow filtration region, and the nucleic lysis region are in one microfluidic device and the amplification region and the detection region are in a second microfluidic device. In another aspect, the present invention provides a method for purifying DNA from a patient sample in a microfluidic device. In accordance with this aspect, the method comprises mixing a patient sample containing cells and a lysis buffer in a mixing region of said microfluidic device. The lysis buffer selectively lyses cellular membranes without lysing nuclear membranes. The method also comprises selectively lysing in a cell lysing region of the microfluidic device the cellular membranes of the cells in the patient sample without lysing the nuclear membranes of the cells to produce intact nuclei from the cells. The method further comprises separating the intact nuclei from the patient sample in a cross-flow filtration region of said microfluidic device. The cross-flow filtration region comprises a filter having a pore size such that the intact nuclei do not pass through the filter and the other components of the patient sample pass through the filter and are carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region. The method also comprises flowing purified nuclei through an interface channel in fluid communication with said cross-flow filtration region for downstream analysis. In some embodiments, the method further comprises driving the flow of one of the lysed patient sample and the cross-flow buffer by a pressure differential and driving the flow of the other of the lysed patient sample and the cross-flow buffer by an electrophoretic voltage potential. In other embodiments, the method further comprises separating the intact nuclei, bacteria and viruses from the lysed patient sample in said cross-flow filtration region in which each of the intact nuclei, bacteria and viruses are released into separate channels with the cross-flow buffer. In another embodiment, the method further comprises separating the intact nuclei, bacteria and viruses from the lysed patient sample in said cross-flow filtration region by a series of filters each having a different pore size. In another embodiment, the method further comprises concentrating the intact nuclei prior to sending the intact nuclei for downstream analysis. In some embodiments, the method further comprises separating the intact nuclei from the lysed patient sample utilizing more than one cross-flow filtration region, each receiving a portion of the lysed patient sample. In some embodiments the patient sample is as described herein. In other embodiments, purifying DNA from cells in a patient sample comprises purifying DNA from white blood cells in the patient sample. In another aspect, the present invention provides a method of determining the presence or absence of a nucleic acid in a patient sample. In accordance with this aspect, the method comprises mixing a patient sample containing cells and a lysis buffer in a mixing region of said microfluidic device. The lysis buffer selectively lyses cellular membranes without lysing nuclear membranes. The method also comprises selectively lysing in a cell lysing region of the microfluidic device the cellular membranes of the cells in the patient sample without lysing the nuclear membranes of the cells to produce intact nuclei from the cells. The method further comprises separating the intact nuclei from the patient sample in a cross-flow filtration region of the microfluidic device. The cross-flow filtration region comprises a filter having a pore size such that the intact nuclei do not pass through the filter and the other components of the patient sample pass through the filter and are carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region. The method also comprises lysing the nuclei to release the nucleic acid in the microfluidic device. The method further comprises amplifying the nucleic acid in the microfluidic device; and determining the presence or absence of an amplified product. The presence of the amplified product indicates the presence of the nucleic acid in the patient sample. In some embodiments, the patient sample is as described herein. In other embodiments the patient sample contains white blood cells. In additional embodiments, the method further comprises enriching the patient sample for white blood cells prior to the selective lysis of the cellular membranes. The enrichment for white blood cells can be performed as described herein. In further embodiments, the mixing of the patient sample and lysis buffer, selectively lysing, separating intact nuclei and lysing the nuclei are performed in one microfluidic device and the amplification and detection are performed in a second microfluidic device. In other embodiments, the mixing of the patient sample and lysis buffer, selectively lysing and separating intact nuclei are performed in one microfluidic device and the lysing the nuclei, amplification and detection are performed in a second microfluidic device. In another aspect, the present invention provides another microfluidic system for isolating DNA from cells in a patient sample. In accordance with this aspect, the microfluidic system comprises a lysis buffer storage device for storing a lysis buffer in which the lysis buffer selectively lyses cellular membranes without lysing nuclear membranes. The system also comprises an elution buffer storage device for storing an elution buffer. The system further comprises a sample card having multiple chambers for receiving the patient sample. Each chamber in the sample card comprises an inlet, a filter and an outlet. The system also comprises a flow control system for controlling flow of the lysis buffer and the elution buffer to each chamber of the sample card. The flow control system controls the flow of lysis buffer into each chamber of the sample card such that the lysis buffer selectively lyses cellular membranes to release nuclei and cell debris causing the cell debris to flow through the filter into a waste receptacle positionable beneath the sample card and without lysing nuclear membranes of nuclei in the patient sample which become trapped on the filter. The system further comprises a temperature control system for heating the filter in the sample card sufficient to lyse nuclei trapped on said filter and release DNA. The system also comprises an interface chip comprising multiple DNA sample wells and DNA sample outlets. The interface chip is positionable beneath the sample card and is configured to receive the DNA released from the lysed nuclei trapped on said filter. The system further comprises a main controller in communication with the temperature control system, and the flow control system. In some embodiments, the temperature control system comprises a heating source and a heat sensor. In other embodiments, the flow control system comprises a pump and a solution delivery chip, wherein the solution delivery chip comprises multiple channels for delivering lysis buffer and elution buffer to each chamber of the sample card. In further embodiments, the flow control system further comprises a pressure control system. The pressure control system comprises an air source, a pressure sensor for controlling the delivery of the elution buffer and the lysis buffer to each chamber of the sample card. In some embodiments, the multiple chambers of the sample card are in fluid communication with one another. In other embodiments, the sample card is disposable. In some embodiments, the sample card is configured to contain multiple different patient samples. In other embodiments, the sample card is configured to contain one patient sample in multiple chambers. In another aspect, the present invention provides a microfluidic system for determining the presence or absence of a nucleic acid in a patient sample. In accordance with this aspect, the microfluidic system comprises a microfluidic device comprising a sample preparation region, an amplification reaction region and a detection region. The sample preparation region comprises a lysis buffer storage device for storing a lysis buffer in which the lysis buffer selectively lyses cellular membranes without lysing nuclear membranes. The sample preparation region also comprises an elution buffer storage device for storing an elution buffer. The sample preparation region further comprises a sample card having multiple chambers for receiving the patient sample. Each chamber comprises an inlet, a filter and an outlet. The sample card is removably insertable into said sample preparation region of said microfluidic device. The sample preparation region also comprises a flow control system for controlling flow of the lysis buffer and the elution buffer to each chamber of said sample card. The flow control system controlling the flow of lysis buffer into each chamber of the sample card such that the lysis buffer selectively lyses cellular membranes to release nuclei and cell debris causing the cell debris to flow through the filter into a waste receptacle positionable beneath the sample card and without lysing nuclear membranes of nuclei in the patient sample which become trapped on the filter. The sample preparation region further comprises a temperature control system for heating the filter in the sample card sufficient to lyse nuclei trapped on said filter and release DNA. The sample preparation region also comprises an interface chip comprising multiple DNA sample wells and DNA sample outlets, wherein said interface chip is positionable beneath the sample card and is configured to receive the DNA released from the lysed nuclei trapped on said filter. The microfluidic system further comprises a main controller in communication with the temperature control system, the flow control system, and the microfluidic chip. In one embodiment, the main controller controls the flow of DNA from the interface chip to the amplification region and/or the detection region of the microfluidic chip. In some embodiments, the temperature control system comprises a heating source and a heat sensor. In other embodiments, the flow control system comprises a pump and a solution delivery chip in which the solution delivery chip comprises multiple channels for delivering lysis buffer and elution buffer to each chamber of the sample card. In some embodiments, the multiple chambers of the sample card are in fluid communication. In other embodiments, the flow control system further comprises a pressure control system, wherein the pressure control system comprises an air source, a pressure sensor for controlling the delivery of the elution buffer and the lysis buffer to each chamber of the sample card. In some embodiments, the multiple chambers of the sample card are in fluid communication in which a patient sample in one chamber can be driven into other chambers. In other embodiments, the sample card is disposable. In another aspect, the present invention provides a method for isolating DNA from cells in a patient sample. In accordance with this aspect, the method comprises providing a microfluidic system comprising (i) a sample card having multiple chambers for receiving the patient sample, wherein each chamber comprises an inlet, a filter and an outlet, said sample card being removably insertable into said microfluidic system, (ii) a flow control system for controlling flow of a lysis buffer and an elution buffer to each chamber of the sample card, (iii) a temperature control system for heating the filter in the sample card; (iv) a waste receptical positionable beneath the sample card, and (v) an interface chip comprising multiple DNA sample wells and DNA sample outlets, wherein said interface chip is positionable beneath the sample card. The method also comprises loading the patient sample into the chambers of the sample card. The method further comprises inserting the sample card into the microfluidic system. The method also comprises delivering lysis buffer to the chamber of the sample card and selectively lysing cellular membranes of the patient sample without lysing nuclear membranes of nuclei, producing a solution comprising lysis buffer, intact nuclei and cellular debris. The method further comprises controlling the flow control system to drive the lysis buffer and the cellular debris through the filter and into the waste receptacle, thereby trapping the intact nuclei on the filter. The method also comprises controlling the temperature control system to heat the filter causing the intact nuclei trapped on the filter to lyse, thereby releasing DNA. The method further comprises delivering an elution buffer to the chambers of the sample card. The method also comprises controlling the flow control system to drive the elution buffer and the DNA to the DNA sample wells in the interface chip. In some embodiments, the lysis buffer is repeatedly delivered to the chambers of the sample card to clean the filters. The above and other embodiments of the present invention are described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention. In the drawings, like reference numbers indicate identical or functionally similar elements. FIG. 1 is a functional block diagram of a DNA preparation and analysis system. FIG. 2 shows a schematic illustration of a microfluidic DNA sample preparation device in accordance with an embodiment of the invention. FIG. 3A illustrates a multi-layered microfluidic sample preparation device in accordance with an embodiment of the invention. FIG. 3B is a longitudinal cross-sectional view of a multi-layered microfluidic sample preparation device in accordance with an embodiment of the invention. FIG. 3C is a transverse cross-sectional view of a multi-layered microfluidic sample preparation device in accordance with an embodiment of the invention. FIG. 4 is an exploded view of a multi-layered microfluidic sample preparation device in accordance with an embodiment of the invention. FIG. 5 illustrates a top view of layer 1 of the microfluidic sample preparation device of FIG. 4 . FIG. 6 is a longitudinal cross-sectional view of layer 1 of the microfluidic sample preparation device of FIG. 4 . FIG. 7 illustrates a top view of layer 2 of the microfluidic sample preparation device of FIG. 4 . FIG. 8 illustrates a top view of layer 3 of the microfluidic sample preparation device of FIG. 4 . FIG. 9 is a longitudinal cross-sectional view of layer 3 of the microfluidic sample preparation device of FIG. 4 . FIG. 10 illustrates a top view of layer 4 of the microfluidic sample preparation device of FIG. 4 . FIG. 11 is a longitudinal cross-sectional view of layer 4 of the microfluidic sample preparation device of FIG. 4 . FIG. 12 illustrates a top view of layer 5 of the microfluidic sample preparation device of FIG. 4 . FIG. 13 is a longitudinal cross-sectional view of layer 5 of the microfluidic sample preparation device of FIG. 4 . FIG. 14 is a flow chart illustrating a process according to an embodiment of the invention. FIGS. 15A and 15B show trapping of nucleic by the membrane. FIG. 15A shows the membrane before trapping the nuclei. FIG. 15B shows the membrane after trapping the nuclei which are dyed with a fluorescence dye. FIG. 16 is a graph showing the results of an experiment. FIG. 17 shows a schematic illustration of a cross-flow microfluidic device for sample preparation in accordance with other embodiments of the present invention. FIG. 18 shows a schematic illustration of a cross-flow filter in accordance with an embodiment of the present invention. FIG. 19 shows a schematic illustration of a cross-flow filter in accordance with other embodiments of the present invention. FIG. 20 shows a schematic illustration of a cross-flow microfluidic device for sample preparation in accordance with further embodiments of the present invention. FIG. 21 is a transverse cross-sectional view of the cross-flow microfluidic device shown in FIG. 20 . FIG. 22 illustrates a sample concentrator in accordance with embodiments of the present invention. FIG. 23 illustrates a system for sample preparation in accordance with other embodiments of the present invention. FIG. 24 is a flow chart illustrating a process for sample preparation according to an embodiment of the invention. FIG. 25 is a flow chart illustrating a process for determining the presence or absence of a nucleic acid in a sample according to an embodiment of the invention. FIG. 26 shows a schematic illustration of a microfluidic device for sample preparation in accordance with other embodiments of the present invention. FIG. 27 illustrates a sample card in accordance with an embodiment of the invention. FIG. 28 illustrates a sample card in accordance with another embodiment of the invention. FIG. 29 illustrates a flow control system in accordance with an embodiment of the invention. FIG. 30 illustrates a solution delivery chip in accordance with an embodiment of the invention. FIG. 31 illustrates a pressure control chip in accordance with an embodiment of the invention. FIG. 32 is a flow chart illustrating a process for sample preparation according to an embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 illustrates a microfluidic DNA analysis system 100 according to some embodiments of the invention. As illustrated in FIG. 1 , system 100 includes a DNA sample preparation sub-system 102 (a.k.a., “the sample preparation unit”), a DNA amplification, analysis and detection subsystem 104 , and a main control system 101 . The present application is primarily directed to the sample preparation unit 102 and earlier filed applications describe various embodiments of subsystem 104 (see e.g., U.S. Pat. Pub. Nos. 2008/0003588, 2008/0130971, 2008/0176230, and 2009/0053726, all of which are incorporated herein in their entirety by this reference). FIG. 2 shows a schematic illustration of a component 200 of sample preparation unit 102 in accordance with an embodiment of the invention. More specifically, FIG. 2 shows a schematic illustration of a microfluidic DNA sample preparation device 200 . As illustrated in FIG. 2 , device 200 comprises a chip 201 , a well 202 formed in chip 201 for storing a lysis buffer, and one or more microfluidic channels 206 formed in chip 201 that fluidly connect well 202 to a mixing region 208 formed in chip 201 , thereby providing a path for the lysis buffer in well 202 to travel to the mixing region 208 . Device 200 also includes a sample well 204 formed in chip 201 for storing a sample to analyzed (e.g., a blood sample). Like well 202 , well 204 is connected in fluid communication with mixing region 208 via one or more channels 205 formed in chip 201 . Mixing region 208 is configured to permit a sample from well 204 and lysis buffer from well 202 to mix. Mixing region 208 , which my simply be a small channel, is connected in fluid communication with a filter 210 (e.g., a permeable membrane or other filter) disposed in chip 201 via a microfluidic channel 209 formed in chip 201 . In some embodiments, filter 210 is made of any combination of one or more of the following: silicon, glass, polymers, polyester, polycarbonate, and nitrocellulose. Filter 210 may have a round shape, rectangular shape, or other shape. In some embodiments, filter 210 comprises a number of pores and the pore sizes may range from 500 nanometers (nm) to 10 micrometers (um). For example, in some embodiments, the pore sizes range from approximately 0.5 um to 10 um. FIGS. 15 a and 15 b illustrate an exemplary embodiment of filter 210 . Channel 209 is configured to function as a cell lysis region. That is, channel 209 is configured to permit the lysis buffer from well 202 to selectively lyse cellular membranes of cells in the patient sample from well 204 without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the patient sample. For example, in the cell lysis region red blood cells may be disrupted before reaching the filter 210 while white blood cells are partially lysed such that nuclei are intact when the mixture reaches filter 210 . As further shown in FIG. 2 , a waste well 212 , a DNA collection well 214 , and an elution buffer well 216 are also formed in chip 201 . Additionally, each of the wells 212 , 214 and 216 are connected in fluid communication with filter 210 via microfluidic channels 213 , 215 and 217 , respectively. In some embodiments, during use, well 216 stores an elution buffer which can be, for example, a Tris buffer, KCl and/or a zwitterion. Main control system 101 , as illustrated in FIG. 1 , can cause the elution buffer to flow into filter 210 . During use of chip 200 , filter 210 forms a nuclei trapping region wherein the intact nuclei from the sample are trapped by filter 210 while other components of the patient sample flow through filter 210 and into waste collection region 212 . Filter 210 also functions as a nuclei lysis region in which the nuclear membranes of the intact nuclei are lysed to release the DNA. The released DNA is forced to flow to DNA collection region 214 . As further shown in FIG. 2 , device 200 may include a heat source 250 . Heat source 250 may be formed in or on chip 201 or may be structurally separate from chip 201 . Heat source 250 may be an electrical heater (i.e., a device that converts electrical energy into heat) or other type of heat producer. Heat source 250 may be controlled by a temperature controller 252 , which may be a module of main controller 101 or a separate component that is in communication with main controller 101 . Heat source 250 is controlled, configured and arranged to transfer heat to filter 210 at desired times. For example, when intact nuclei are trapped by filter 210 , heat source 250 may be controlled to cause the transfer of heat to filter 210 , which heat is preferably sufficient to lyse or facilitate the lysing of the nuclear membranes of the nuclei, thereby releasing the DNA contained by the nuclear membranes. In some embodiments, chip 201 is a multilayer chip. That is, chip 201 may comprise two or more boards. Referring now to FIGS. 3A-3C , a multilayered embodiment of device 200 is illustrated. In the non-limiting embodiment illustrated in FIG. 3A , device 200 includes six layers. However, fewer or more layers also could be used. FIG. 3B shows a longitudinal cross-sectional view of device 200 in accordance with the embodiment shown in FIG. 3A , and FIG. 3C shows a transverse cross-sectional view of device 200 in accordance with the embodiment shown in FIG. 3A . FIG. 4 illustrates an exploded view of the embodiment of device 200 shown in FIG. 3A . In the first layer (or top layer) 401 , a top view of which is shown in FIG. 5 , wells 202 , 204 and 216 are formed for containing the lysis buffer, sample and elution buffer, respectively. Also formed in layer 401 is a through hole 402 in fluid communication with DNA collector well 214 and a through hole 404 in fluid communication with waste well 212 . In one non-limiting embodiment, layer 401 is preferably approximately five (5) millimeters thick and is made from Poly(methyl methacrylate) (PMMA). Other thicknesses and materials also may be used for this layer in additional embodiments. As further shown in FIG. 5 and FIG. 6 , which is a longitudinal cross sectional view of layer 401 , well 202 has a port 405 in its bottom surface so that fluid can flow from well into channels 206 . Likewise, well 204 has a port 406 in its bottom surface so that fluid can flow from well 204 into channel 205 . Thus, ports 405 and 406 are in fluid communication with mixing region 208 . Similarly, well 216 has port 407 in its bottom surface so that fluid can flow from well 216 into channel 217 . As shown in FIG. 4 , channels 205 , 206 and 217 are formed in the second layer 411 of device 200 . FIG. 7 illustrates a top view of second layer 411 . As shown in FIG. 7 , formed in second layer 411 are a mixing region 208 , channel 209 , through holes 413 , 414 and 415 , and closed bottom wells 416 , 417 , and 418 . Channel 209 fluidly connects mixing region 208 with hole 413 so that a lysis buffer and sample mixture, which may be formed in mixing region 208 , can flow into hole 413 and down to the third layer 421 of device 200 . Likewise, channel 217 connects well 418 , which is positioned directly beneath hole 407 of elution buffer well 216 , with hole 413 so that elution buffer can flow from well 216 into hole 413 and down to the third layer of device 200 . Through hole 414 is positioned beneath through hole 404 so that fluid may flow through hole 414 into hole 404 , and through hole 415 is positioned beneath through hole 402 so that fluid may flow through hole 415 into hole 402 . In one non-limiting embodiment, the second layer 411 of device 200 may comprise a 150 micrometer thick cyclic olefin copolymer (COC) film. Other thicknesses and materials also may be used for this layer in additional embodiments. FIG. 8 illustrates a top view of third layer 421 which includes through holes 422 , 423 and 424 . Through hole 422 is positioned beneath through hole 414 so that fluid may flow through hole 422 into hole 414 , through hole 423 is positioned beneath through hole 413 , so that fluid may flow through hole 413 into hole 423 , and through hole 424 is positioned beneath through hole 415 so that fluid may flow through hole 423 into hole 415 . FIG. 9 shows a longitudinal cross-sectional view of layer 421 . In one non-limiting example, the third layer 421 of device 200 may comprise a 1 millimeter thick PMMA board. Other thicknesses and materials also may be used for this layer in additional embodiments. FIG. 10 illustrates a top view of fourth layer 431 which includes through holes 432 , 433 and 434 . Through hole 432 is positioned beneath through hole 422 so that fluid may flow through hole 432 into hole 422 , through hole 433 is positioned beneath through hole 423 , so that fluid may flow through hole 423 into hole 433 , and through hole 434 is positioned beneath through hole 424 so that fluid may flow through hole 434 into hole 424 . FIG. 11 shows a longitudinal cross-sectional view of layer 421 . In one non-limiting embodiment, the fourth layer 431 of device 200 may comprise a 1 millimeter thick PMMA board. Other thicknesses and materials also may be used for this layer in additional embodiments. As shown in FIG. 4 , filter 210 is sandwiched between the third and fourth layers of device 200 . In some embodiments, filter 210 may be made of any combination of one or more of silicon, glass, polymers, polyester, polycarbonate, and nitrocellulose, as described above. In one non-limiting embodiment, filter 210 is approximately 9 mm by 9 mm and has a thickness of approximately 10 μm. The filter may have other thicknesses and dimensions in additional embodiments. FIG. 12 illustrates a top view of fifth layer 441 . As shown in that figure, closed bottom wells 212 , 443 and 214 are formed on the top surface of layer 441 . Also, microfluidic channel 215 is formed on the top surface of layer 441 as well as channel 213 , which connects well 443 with waste collection well 212 . Closed bottom wells 212 , 443 , and 214 are positioned beneath through holes 432 , 433 , 434 , respectively. FIG. 13 shows a longitudinal cross-sectional view of layer 441 . On one non-limiting embodiment, the fifth layer 441 of device 200 may comprise a 150 micrometer thick COC film. Other thicknesses and materials also may be used for this layer in additional embodiments. As illustrated in FIG. 4 , the sixth layer of device 200 is a base layer 451 . In one non-limiting embodiment, layer 451 may comprise a 1 millimeter thick board made of PMMA. Other thicknesses and materials also may be used for this layer in additional embodiments. In some embodiments, the third, fourth and sixth layers are removed, thereby creating a three layer device. Referring now to FIG. 14 , a flow chart illustrating a process 1400 for preparing DNA for analysis using device 200 is shown. Process 1400 may begin in step 1402 , where a sample (e.g., a sample of blood containing white blood cells) is introduced into sample well 204 . In step 1404 , a lysis buffer is introduced into lysis buffer well 202 . In step 1405 , the lysis buffer is forced to flow out of well 202 through port 405 and channel 206 into mixing region 208 . At or about the same time, the sample is forced to flow out of sample well 204 through port 406 and channel 205 into mixing region 208 . In step 1406 , the lysis buffer and sample mix in the mixing region 208 and the mixture is forced to flow to filter 210 via channel 209 . In embodiments where the sample contains white blood cells, the sample may be enriched for white blood cells prior to introducing the sample into mixing region 208 . While the lysis buffer/patient sample mixture is in channel 209 and travelling towards filter 210 , the lysis buffer selectively lyses the cellular membranes of cells in the patient sample without lysing the nuclear membranes of cells to produce intact nuclei from the cells, as reflected in step 1407 . When the mixture reaches filter 210 , the mixture preferably contains released intact nuclei from the patient sample. In step 1408 , the intact nuclei are trapped by filter 210 while the waste (i.e., other components of the sample and lysis buffer) passes through filter 210 and is forced to travel via channel 213 to waste collection well 212 . In step 1410 , the intact nuclei trapped on filter 210 are lysed, thereby releasing DNA from the lysed nuclei. In some embodiments, the step of lysing the intact nuclei comprises causing an elution buffer in well 216 to flow to filter 210 via channel 217 and/or heating the trapped nuclei using heater 250 . In some embodiments, the elution buffer comprises a Tris buffer, KCl and/or a zwitterion. In some embodiments, the elution buffer is an amplification reaction buffer. In embodiments where heat is used to lyse the trapped nuclei, the trapped nuclei may be heated at a temperature in the range of approximately 35 degrees centigrade to 95 degrees centigrade for approximately 1 to 10 minutes. For example, in one embodiment, the trapped nuclei may be heated at a temperature in the range of approximately 50 degrees centigrade for approximately 7 minutes. In step 1412 , after lysing the intact, trapped nuclei, the DNA released from the nuclei is collected in the DNA collection well 214 . For example, the released DNA flows out of filter 210 and to well 214 via channel 215 . In some embodiments, the released DNA flows to well 214 by flowing an elution buffer from well 216 such that the elution buffer flows out of port 407 and into channel 217 , then through channel 217 to and through the filter 210 where the released DNA mixes with the elution buffer, and then flows through channel 215 into well 214 . Once in well 214 , the mixture containing the released DNA and elution buffer can be removed from chip 201 via through holes 402 , 415 , 424 , and 434 , all of which are in fluid communication with well 214 . While not shown, it is well known in the art that device 200 may be coupled to a flow control system (e.g., a system that comprises one or more pumps) for causing the various buffers, samples and mixtures to flow as described above. Additionally, device 200 may be coupled with a microfluidic platform. The DNA purified by device 200 may be directly delivered by a pump to a well in the microfluidic platform, and further mix with other PCR components. FIGS. 15A and 15B show trapping of nucleic acid by the membrane in accordance with an embodiment of the present invention. Specifically, FIG. 15A shows fluorescence emitted from membrane prior to the membrane trapping dye stained nuclei, and FIG. 15B fluorescence emitted from membrane after the membrane has trapped dye stained nuclei. Referring now to FIG. 16 , a graph is provided showing results achieved from using an above-described method. In particular, DNA purification was tested using 9 patient blood samples. After obtaining purified DNA using this method, one fraction of purified DNA sample was quantified by Pico green method (fluorescence based method for measuring total DNA concentration). Another fraction of purified DNA sample was quantified by real time-PCR. The results show that real time-PCR result is comparable to Pico green assay, indicating that no significant amount of inhibits exist in the purified DNA sample. The table below provides representative dimensions for many of the above described components of device 200 . These dimensions are illustrative and not intended to be limiting in any way. TABLE 1 Component Dimensions chip 201 length: 42 mm; width: 28 mm; height: 8.3 mm channel 206 length: 28 mm; width: 150 μm; depth: 150 μm channel 205 length: 5.4 mm; width: 100 μm; depth: 150 μm channel 209 length: 100 mm; width: 200 μm; depth: 150 μm channel 213 length: 7.75 mm; width: 400 μm; depth: 150 μm channel 215 length: 42 mm; width: 100 μm; depth: 150 μm channel 217 length: 36 mm; width: 100 μm; depth: 150 μm Referring now to FIG. 17 , a schematic illustration is provided of various components of sample a preparation sub-system 102 according to other embodiments of the present invention. As shown in FIG. 17 , system 102 may include a sample well 1702 for containing a sample (e.g., a sample of blood containing white and red blood cells), a lysis buffer well 1704 for containing a lysis buffer, and a channel 1706 in fluid communication with wells 1702 and 1704 via channels 1703 and 1705 , respectively. Channel 1706 may function as a cell lysis region. That is, channel 1706 may be configured such that the lysis buffer from well 1702 is permitted to mix with the sample from sample well 1704 resulting in the selective lysing of cellular membranes of cells in the sample without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the sample. As further shown in FIG. 17 , system 102 may include a cross-flow filtration region 1708 in fluid communication with channel 1706 . In some embodiments, in region 1708 intact nuclei (or white cells or other target components) are separated from other components of the sample (e.g., proteins and other PCR inhibitors) by one or more cross-flow filters 1710 , each having a pore size such that the target components (e.g., intact nuclei) are prevented from being carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region, but other components of the patient sample flow through filters and are carried away by the cross-flow buffer. In the non-limiting embodiment shown in FIG. 17 , cross-flow filtration region 1708 includes four cross flow filters 1710 that are connected in parallel. In other embodiments, region 1708 may have one, two, three or five or more filters 1710 . Additionally, in some embodiments, some filters 1710 may be arranged in series. Moreover, each filter 1710 may have a different average pore size. System 102 may also include a concentrator region 1712 , which is in fluid communication with cross flow filtration region 1708 , in which the intact nuclei from the cross-flow filtration region are concentrated. An interface region 1714 may be in fluid communication with concentrator 1712 . As will be explained herein, purified intact nuclei preferably exit concentrator 1712 and enter interface region 1714 , which includes one or more interface channels through which purified nuclei flow for downstream processing and analysis. FIG. 18 further illustrates an embodiment of cross-flow filter 1710 . As shown in FIG. 18 , cross-flow filter 1710 includes a microfluidic separation channel 1802 , which, as shown in FIG. 17 , is in fluid communication with the cell lysis region 1706 and concentrator 1712 . Channel 1802 is configured such that fluid entering channel 1802 from channel 1706 can flow through channel 1802 such that the fluid will reach and enter the concentration region 1712 . A filter 1810 and a filter 1812 are disposed in a middle portion of channel 1802 . Filters 1810 and 1812 are arranged to form a separation chamber 1814 . In operation, while the lysis buffer/sample mixture is flowing through channel 1802 (i.e., from the input end 1832 to the output end 1834 ), a cross-flow fluid is introduced into the portion of channel 1802 having the filters 1810 and 1812 via a cross-flow buffer input port 1804 . The cross-flow fluid exits this portion of the channel 1802 via a cross-flow buffer output port 1806 . Advantageously, there is a differential (e.g., a pressure differential or voltage differential, such as an electrophoretic voltage potential, or a gravitational field) between ports 1804 and 1806 that causes the cross-flow fluid that enters channel 1802 via port 1804 to flow first through filter 1810 , then through separation chamber 1814 , then through filter 1812 , and finally out of channel 1802 via exit port 1806 . There is also a force (e.g., pressure, electric, gravity) that causes fluid entering channel 1802 to flow from end 1832 to end 1834 . As the cross-flow buffer flows across separation chamber 1814 (as illustrated by the dashed lines), the cross-flow buffer together with filters 1810 and 1812 facilitate the separation of the intact nuclei from the other components of the mixture that flows into channel 1802 from cell lysis region 1706 . More specifically, the pore size of the filters 1812 and 1810 are such that the intact nuclei do not pass through filter 1812 , but are driven toward the concentrator region 1712 by the flow of fluid from end 1832 to end 1834 , whereas other, smaller components of the sample are driven through filter 1812 and driven towards exit port 1806 via the cross-flow of the cross-flow buffer. In this manner, intact nuclei (or other target material) can be efficiently separated from the other components of the sample. Preferably, one type of force (e.g., air pressure) is used to cause fluid entering channel 1802 to flow from end 1832 to end 1834 , while a different type of force (e.g. an electrical field, gravity) is used to cause the cross-flow fluid to flow from 1804 to 1806 . In some embodiments, the size of the pores of filters 1810 and 1812 is between approximately 1 um and 15 um. For example, the size of the pores of filter 1812 may be about 5 um. In some embodiments, filters 1810 and 1812 may consists of or include a membrane and/or an array of pillars. Referring now to FIG. 19 , a cross-flow filter 1710 according to another embodiment is illustrated. As shown in FIG. 19 , cross-flow filter 1710 may include a microfluidic separation channel 1902 . In an exemplary embodiment, filters 1910 , 1912 , 1916 , and 1918 are disposed in a middle portion of channel 1902 . Filters 1910 , 1912 , 1916 , and 1918 are arranged to form separation chambers 1914 a , 1914 b , and 1914 c. In operation, while the lysis buffer/sample mixture is flowing through channel 1902 (e.g., from the input end 1932 towards an output end 1934 a ), a cross-flow fluid is introduced into the portion of channel 1902 having the filters via a cross-flow buffer input port 1904 . The cross-flow fluid exits the portion of channel 1902 having the filters via a cross-flow buffer output port 1906 . Advantageously, there is a differential (e.g., a pressure differential or voltage differential, such as an electrophoretic voltage potential) between ports 1904 and 1906 that causes the cross-flow fluid that enters channel 1902 via port 1904 to flow first through filter 1910 , then through separation chamber 1914 a , then through filter 1912 , then through separation chamber 1914 b , then through filter 1916 , then through separation chamber 1914 c , then through filter 1918 , and finally out of channel 1902 via exit port 1906 . There is also a differential (e.g., pressure or electric) that causes fluid entering separation chambers 1914 a , 1914 b , and 1914 c to flow towards ends 1934 a , 1934 b , and 1934 c , respectively. As the cross-flow buffer flows across a separation chamber 1914 a , the cross-flow buffer together with the filters that form the separation chamber 1914 a facilitate the separation of desired components (e.g., intact nuclei, bacteria, viruses) from the other components of the mixture that flows into the separation chamber. More specifically, for example, the pore size of the filters 1912 and 1910 are such that the intact nuclei do not pass through filter 1912 , but are driven toward end 1934 by a differential, whereas other, smaller components of the sample (e.g., bacteria, viruses or waste material) are driven through filter 1912 and into separation chamber 1914 b by the flow of the cross-flow buffer. For example, the average pore size of filter 1912 may be between approximately 1 um and 15 um. In one embodiment, the average pore size is about 8 um. The pore size of the filter 1916 may be such that bacteria does not pass through filter 1916 , but are driven toward end 1934 b by a differential, whereas other, smaller components of the sample (e.g., viruses) are driven through filter 1916 into separation chamber 1914 c by the flow of the cross-flow fluid. For example, the average pore size of filter 1916 may be between approximately 0.2 um and 2 um. In one embodiment, the average pore size is about 0.4 um. The pore size of the filter 1918 may be such that viruses do not pass through filter 1918 , but are driven toward end 1934 c by a differential, whereas other, smaller components of the sample are driven through filter 1918 and driven towards exit port 1906 via the cross-flow of the cross-flow buffer. For example, the average pore size of filter 1918 may be between approximately 10 nm 400 nm. In one embodiment, the average pore size is about 100 nm. Port 1961 may be used to create a pressure differential between port 1961 and end 1934 b so that a fluid in chamber 1914 b will flow towards end 1934 b . Likewise, Port 1962 may be used to create a pressure differential between port 1962 and end 1934 c so that a fluid in chamber 1914 c will flow towards end 1934 c. In the above manner, intact nuclei, bacteria and viruses may be separated from the sample collected in separate target collection ports using the cross flow filter 1710 as illustrated in FIG. 19 , in accordance with one embodiment. Referring now to FIG. 20 , a layered embodiment of filter 1710 in illustrated. As shown in FIG. 20 , a filter 1710 may include three layers: a top layer 2002 , a middle layer 2004 , and a bottom layer 2006 . A filter 2008 may be formed in top layer 2002 , one or more separation channels 2010 may be formed in middle layer 2004 , and a filter 2012 may be formed in bottom layer 2006 . At least a portion of the separation channel 2010 extends from the top surface of layer 2004 to the bottom surface of layer 2004 , as shown in FIG. 21 , which shows a cross sectional view of this embodiment of filter 1710 . As shown in FIG. 21 , layer 2002 is positioned on top of layer 2004 such that filter 2008 is on top of channel 2010 , thereby forming a top, porous wall of channel 2010 . Likewise, as shown in FIG. 21 , layer 2006 is positioned beneath layer 2004 such that filter 2012 is underneath channel 2010 , thereby forming a bottom, porous wall of channel 2010 . In operation, while the lysis buffer/sample mixture is flowing through channels 2010 (i.e., from the input end 2006 to the output end 2014 ), a cross-flow fluid is introduced into the portion of channel 2010 having the filters 2008 and 2012 via a cross-flow buffer input port (not shown). The cross-flow fluid exits this portion of the channel 2010 via a cross-flow buffer output port (also not shown). As with previous embodiments, there is a differential (e.g., a pressure differential or voltage differential, such as an electrophoretic voltage potential, or a gravitational field) between the cross-flow buffer input and output ports that causes the cross-flow fluid that enters channel 2010 to flow first through filter 2008 , then through the separation chamber, then through filter 2012 , and finally out of channel via the exit port. There is also a force (e.g., pressure, electric, gravity) that causes fluid entering channel 2010 to flow from end 2006 to end 2014 . As with previous embodiments, as the cross-flow buffer flows across separation chamber, the cross-flow buffer together with filters 2008 and 2012 facilitate the separation of the intact nuclei from the other components of the mixture that flows into channel 2010 from, for example, the cell lysis region 1706 . Referring back to FIG. 17 , as described above, system 102 may include a concentrator 1712 , as further illustrated in FIG. 22 . As shown in FIG. 22 , a concentrator 1712 , in accordance with one exemplary embodiment, includes a generally triangular shaped channel 2208 (i.e., a channel wherein the width of the channel increases as one moves from an input end to an output end). At the input end of channel 2208 there is an inlet 2202 providing a means for a fluid (e.g., the purified sample collected in cross flow filtration region 1708 , which also contain some waste components from the blood sample and lysis buffer) to enter into channel 2208 . At the opposite end of channel 2208 (i.e., at the output end) there are two waste outlets ( 2204 a and 2204 b ), each of which provides a means for additional waste to exit channel 2208 , and a sample outlet 2206 that provides a means for the desired concentrated fluid to exit channel 2208 . As further shown in FIG. 22 , two filters ( 2210 a and 2210 b ) are disposed in channel 2208 and together form a separation chamber 2212 in channel 2208 . Separation chamber 2212 includes an fluid entry point 2214 that is positioned downstream from inlet 2202 and a fluid exit point 2216 that is adjacent the output end of channel 2208 and that is in fluid communication with outlet 2206 , but not in fluid communication with any of the waste outlets 2204 . Referring back to FIG. 17 , it can be seen that after the intact nuclei exit filtration region 1708 , the intact nuclei, as well as any waste matter not removed by filtration region 1708 , will flow into the channel 2208 of concentrator 1712 . Referring back now to FIG. 22 , when the intact nuclei and any waste material enter channel 2208 , the mixture will be forced to flow into separation chamber 2212 by, for example, a pressure differential (or other force) between the input end and the output end of channel 2208 . When the mixture is in chamber 2212 , some of the mixture will flow through filter 2210 a towards waste outlet 2204 a , some will flow through filter 2210 b towards waste outlet 2204 b , and the rest will flow the entire length of chamber 2212 and into channel 2223 and eventually to outlet 2206 . For example, the pressure in chamber 2212 may be higher than the pressure at outlets 2204 a , 2204 b and 2206 , thereby forcing some of the mixture to flow to the outlets. Advantageously, the filters 2210 are configured such that the intact nuclei in the mixture are not able to pass through or enter the filter, but any waste material is able to flow through the filter. Accordingly, the mixture that leaves chamber 2212 will have a higher concentration of intact nuclei than the mixture that entered chamber 2212 . As illustrated in FIG. 17 , outlet 2206 of concentrator 1712 is in fluid communication with an inlet of an interface channel of interface region 1714 . Accordingly, in some embodiments, as described above, a mixture containing a concentrated amount of intact nuclei may flow into the interface channels of interface region 1714 for further testing and analysis. The interface region 1714 in accordance with one embodiment is further illustrated in FIG. 23 . As shown in FIG. 23 , interface region 1714 may contain a number of microfluidic channels 2304 , such as, for example, 8 microfluidic channels. In some embodiments, the intact nuclei that exit concentrator 1712 are forced to flow through channels 2304 as is know in the art. As is also known in the art, as the intact nuclei flow, DNA from the intact nuclei may be released by lysing the nuclei. The DNA released from the intact nuclei may be amplified as they traverse channels 2304 using, for example, a PCR technique. In such an embodiment, a temperature control system 2306 controls the temperature of the DNA flowing though channels 2304 to create the PCR reaction. Thus, a portion of channels 2304 may be considered an amplification region. A camera 2302 may be positioned relative to channels 2304 to record fluorescent emissions from channels 2304 and thereby detect amplification of the DNA. Systems and methods for amplifying DNA and detecting the amplification of the DNA are described in the above-referenced patents. In some embodiments, a concentrator is not used and the purified intact nuclei from the cross flow filtration region 1708 are caused to flow directly into the interface region 1714 . Referring now to FIG. 24 , a flow chart is provided which illustrates a process 2400 according to an embodiment of the invention for using the system shown in FIG. 17 . Process 2400 may begin in step 2402 , wherein fluid from well 1702 (e.g., a blood sample) and a lysis buffer from well 1704 are mixed. That is, the blood sample and lysis buff are forced to flow out of wells 1702 and 1704 , respectively, and into channel 1706 , where the sample and lysis buffer mix. In some embodiments the fluids may be forced out of wells 1702 and 1704 by creating a pressure differential or an electrophoretic voltage. In step 2404 , while the mixture is flowing along channel 1706 , the lysis buffer selectively lyses, in cell lysing region 1706 , the cellular membranes of the cells in the sample without lysing the nuclear membranes of the cells to produce intact nuclei from the cells. In step 2406 , the intact nuclei is separated from the sample in a cross-flow filtration region 1708 , which includes one or more cross-flow filters 1710 that has a pore size such that the intact nuclei are not permitted do not pass through the filter and the other components of the patient sample pass through the filter and are carried away by a cross-flow buffer that is controlled to flow through the cross-flow filtration region. In some embodiments, the cross-flow buffer is driven through the cross-flow filtration region by a pressure differential or by an electrophoretic voltage. In step 2408 , which is optional, the intact nuclei are concentrated by concentrator 1712 . In step 2410 , the concentrated nuclei are forced to flow through an interface channel 1714 for downstream analysis. In some embodiments, the cross-flow region may have multiple filters to filter out not only intact nuclei from the sample, but also bacteria and viruses. For example, the cross-flow filtration region may have three filters, one for separating nuclei from the sample, one for separation bacteria from the sample, and one for separating viruses from the sample, as described above in connection with FIG. 19 . In other embodiments, the cross-flow filter 1710 is configured such that the purified sample from output end 1834 is recirculated back into the input end 1832 for additional passes through separation chamber 1814 for further purification. In one embodiment, this recirculation is accomplished by providing a channel connecting output end 1834 with input end 1832 to permit fluid flow there between, and controllably driving fluid from the output end into the input end by, for example, pressure differential. Referring now to FIG. 25 , a flow chart is provided illustrating a process 2500 of determining the presence or absence of a nucleic acid in a patient sample according to an embodiment of the invention. Process 2500 may begin in step 2502 , where a patient sample containing cells is mixed with a lysis buffer in a mixing region of a microfluidic device (e.g., region 1706 ), wherein the lysis buffer selectively lyses cellular membranes without lysing nuclear membranes. Next, in step 2504 , the lysis buffer selectively lysis in the mixing region 1706 (a.k.a., “cell lysing region”) the cellular membranes of the cells in the patient sample without lysing the nuclear membranes of the cells to produce intact nuclei from the cells. In step 2506 , the intact nuclei are separated from the patient sample in cross-flow filtration region 1708 as described above. In step 2508 , the nuclei are lysed to release nucleic acid. In step 2510 , the nucleic acid is amplified (e.g., amplified using PCR). In step 2512 , the presence or absence of an amplified product is determined, wherein the presence of the amplified product indicates the presence of the nucleic acid in the patient sample. In some embodiments, the patient sample is first enriched for white blood cells prior to the selective lysis of the cellular membranes. In some embodiments, steps 2502 - 2508 are performed one microfluidic device and steps 2510 - 2512 are performed in a different microfluidic device. In other embodiments, steps 2502 - 2506 are performed one microfluidic device and steps 2508 - 2512 are performed in a different microfluidic device. Referring now to FIG. 26 , subsystem 102 is illustrated in according with another embodiment. As shown in FIG. 26 , the sample preparation subsystem 102 includes a sample card 2600 that has one or more chambers 2601 that are configured to hold one or more patient samples. Each of the one or more chambers 2601 comprises an inlet 2602 , a filter 2603 , and an outlet 2604 . The sample card 2600 is removably insertable into the sample preparation subsystem 102 , which allows the sample card 2600 to be loaded with the one or more patient samples, and then inserted into the sample preparation subsystem 102 . Each inlet 2602 further comprises one or more channels which may or may not be in fluid communication with each other. FIG. 27 further illustrates one embodiment of the sample card 2600 containing one or more chambers 2601 . As shown in FIG. 27 , each chamber 2601 comprises an inlet 2602 , a filter 2603 , and an outlet 2604 . The filter pore size may be between 1 to 15 um, and preferably is approximately 5 um. As shown in FIG. 26 , the sample preparation subsystem 102 includes a flow control system 2605 that controls the flow of a lysis buffer from a lysis buffer storage device 2606 into each chamber 2601 of the sample card 2600 through inlets 2602 . The lysis buffer contained in the lysis buffer storage device 2606 selectively lyses cellular membranes to release nuclei and cell debris. The flow control system 2605 then causes the cell debris and lysis buffer to flow through the filter 2603 , through outlets 2604 , and into a removably insertable waste receptacle 2607 , while leaving the nuclei trapped on the filter 2603 . The waste receptacle 2607 is positionable beneath the outlets 2604 to receive the cell debris and lysis buffer from the chambers 2601 . The lysis buffer does not lyse the nuclei from the patient sample. The flow control system 2605 also controls the flow of an elution buffer from an elution buffer storage device 2608 into each chamber 2601 of the sample card 2600 through the inlet 2602 . As shown in FIG. 26 , the sample preparation subsystem 102 includes a temperature control system 2609 that controls the temperature of the sample card 2600 . The temperature control system 2609 heats the sample card 2600 , which causes the nuclei trapped on the filter 2603 to lyse, thereby releasing the DNA of the nuclei. In this embodiment, the temperature control system uses a sensor 2610 and a heat source 2611 to controllably and effectively heat the sample card to lyse the intact nuclei. FIG. 26 further illustrates an interface chip 2612 which is removably insertable into the sample preparation subsystem 102 . The interface chip 2612 is positionable beneath the sample card 2600 and is configured to receive the DNA released from the lysed nuclei trapped on the filter 2603 . As shown in FIG. 26 , the interface chip 2612 comprises one or more DNA sample wells 2613 which are in fluid communication with one or more DNA sample outlets 2614 . When inserted into the subsystem 102 , the DNA sample wells 2613 are each aligned with an outlet 2604 from the sample card 2600 , which enables each DNA sample well 2613 to collect the DNA released by the lysed nuclei as the DNA exit the sample card 2600 through the outlet 2604 . In this embodiment, the main controller 101 communicates with the temperature control system 2609 and the flow control system 2605 . As those skilled in the art will recognize, many options exist for a main controller 101 , such as, for example, a general purpose computer or a special purpose computer. Other specialized control equipment known in the art could also serve the purpose of the main controller 101 . Referring to FIG. 28 , a sample card 2600 is illustrated with multiple chambers 2601 connected by fluidic channels 2800 . In this embodiment, connecting chambers 2601 using a fluidic channel 2800 allows different numbers of samples to be tested in varying volumes. For example, in the embodiment shown where all chambers 2601 are in fluidic communication via fluidic channels 2800 , the sample card 2600 would allow one patient sample to be tested in a larger volume because every chamber 2601 , being in fluidic communication, would contain the same sample. Alternatively, if none of the chambers 2601 were in fluidic communication, as shown in FIG. 27 , the sample card 2600 would allow testing of multiple patient samples simultaneously, in which each sample could be from the same patient or different patients. When none of the chambers 2601 are in fluidic communication, the number of patient samples to be tested would be limited by the number of chambers 2601 on the sample card 2600 . While FIG. 28 shows all chambers 2601 being connected, other arrangements are contemplated. The number of chambers 2601 connected together on a sample card 2600 could be many different combinations, which would allow for testing of a desired number of patient samples and a desired volume of each patient sample. For example, a sample card A 200 could be configured to connect the chambers 2601 in pairs via fluidic channels 2800 , which would reduce the number of different patient samples by half, while doubling the volume of each patient sample to be tested. The sample card 2600 can be made from various materials which might depend on the testing requirements of each application; the sample card 2600 can be reusable or disposable to reflect the requirements of each testing application. FIG. 29 further illustrates the flow control system 2605 according to one embodiment. As shown in FIG. 29 , the flow control system 2605 is controlled by the main controller 101 and comprises a pump 2900 , a pressure control system 2901 , a solution delivery chip 2902 , and a pressure control chip 2903 . The pressure control system 2901 comprises an air source and a pressure sensor which allows the flow control system 2605 to control the delivery of the elution buffer and the lysis buffer to the sample card 2600 using pressure to move the solutions. The solution delivery chip 2902 comprises multiple channels for delivering lysis buffer and elution buffer to each chamber 2601 of the sample card 2600 . The pressure control chip 2903 comprises multiple channels for providing pressure to each chamber 2601 of the sample card 2600 . While this embodiment illustrates the use of a solution delivery chip 2902 , a pump 2900 , and a pressure control system 2901 in the flow control system 2605 , the different components can be used in different combinations. For example, the pump 2900 and the solution delivery chip 2902 can be used without the pressure control system 2901 . In another embodiment, the pressure control system 2901 can comprise multiple channels for controlling air pressure in each chamber 2601 of the sample card 2600 . Referring to FIG. 30 , the solution delivery chip 2902 is illustrated according to one embodiment. As shown in FIG. 30 , the solution delivery chip comprises multiple channels 3000 in fluidic communication the chambers 2601 of the sample card. The channels 3000 comprise one or more solution inlets 3001 which receive the buffers from the pump 2900 . The channels 3000 further comprise one or more solution outlets 3002 that are in fluid communication with the inlets 2602 of the sample card 2600 which allows the lysis buffer and the elution buffer to be delivered to the chambers 2601 of the sample card 2600 via the solution outlets 3002 of the solution delivery chip 2902 . Referring to FIG. 31 , the pressure control chip 2903 is illustrated according to one embodiment. As shown in FIG. 31 , the pressure control chip 2903 comprises multiple pressure channels 3100 , and each pressure channel 3100 is in fluid communication with a pressure inlet 3101 and a pressure outlet 3102 . In this embodiment, each pressure channel is in fluid communication with the same pressure inlet 3101 ; however, other embodiments are contemplated where there may be more than one pressure inlet 3101 . The pressure inlet 3101 is in fluid communication with the pressure control system 2901 in order to deliver pressure to the pressure control chip 2903 . The pressure outlets 3102 are in fluid communication with the inlets 2602 of the sample card 2600 , which allows the pressure control chip 293 to deliver pressure to the chambers 2601 of the sample card 2600 . FIG. 32 is a flowchart illustrating a method 3200 for isolating DNA cells in a patient sample. While the method 3200 is not limited to the system provided in FIG. 26 , one preferred embodiment of the method can utilize a system similar to that shown in FIG. 26 , and FIG. 26 is used for reference purposes to assist in describing the method. As shown in FIG. 32 , in step 3202 a sample preparation system 102 is provided, wherein the system comprises: (i) a sample card 2600 having multiple chambers 2601 , wherein each chamber 2601 comprises an inlet 2602 , a filter 2603 , and an outlet 2604 , where the sample card 2600 is removably insertable into the sample preparation subsystem 102 ; (ii) a flow control system 2605 for controlling flow of a lysis buffer and an elution buffer to each chamber 2601 of the sample card 2600 ; (iii) a temperature control system 2609 for heating the filter 2603 in the sample card 2600 ; (iv) a removably insertable waste receptacle 2607 which is positionable beneath the sample card 2600 ; and (v) an interface chip 2612 comprising multiple DNA sample wells 2613 and DNA sample outlets 2614 , where the interface chip 2612 is positionable beneath the sample card 2600 . In step 3204 , the patient sample is loaded into the chambers 2601 of the sample card 2600 . In step 3206 , the sample card 2600 containing the patient sample is inserted into the sample preparation system 102 . In step 3208 , the flow control system 2605 delivers a lysis buffer from the lysis buffer storage device 2606 to the chamber 2601 of the sample card 2600 through the inlet 2602 . The lysis buffer selectively lyses the cellular membranes of the patient sample without lysing the nuclear membranes of the nuclei. The reaction produces a solution comprising a lysis buffer, intact nuclei and cellular debris, in the chamber 2601 of the sample card 2600 . In step 3210 , the removably insertable waste receptacle 2607 is positioned below the sample card 2600 and the flow control system 2605 operates to drive the solution through the filter 2603 of the chamber 2601 . The filter 2603 traps the intact nuclei from the solution while the lysis buffer and the cellular debris are driven out of the chamber 2601 through the outlet 2604 by the flow control system 2605 . The lysis buffer and cellular debris are collected when exiting the chamber 2601 through the outlet 2604 in the waste receptacle 2607 . In step 3212 , the temperature control system 2609 operates to heat the filter 2603 , which heats the intact nuclei trapped in the filter 2603 . The heating of the intact nuclei causes the nuclei to lyse, which releases DNA from the nuclei. In step 3214 , the flow control system 2605 operates to deliver the elution buffer from the elution buffer storage device 2608 to the chamber 2601 of the sample card 2600 through the inlet 2602 . In step 3216 , the interface card 2612 is positioned beneath the sample card 2600 , and the flow control system 2605 operates to drive the elution buffer and the DNA through the outlet 2604 of the chamber 2601 while leaving the lysed nuclei on the filter 2603 . The elution buffer and DNA are deposited in the DNA sample well 2613 of the interface chip 2612 after exiting the chamber 2601 though the outlet 2604 . This method thus allows the DNA to be isolated from the patient sample. An optional step following the DNA isolation described above can be to deliver the lysis buffer from the lysis buffer containment device 2606 into the chambers 2601 of the sample card 2600 using the flow control device 2605 , then drive the solution out of the chamber 2601 through the outlet 2604 by operation of the flow control system 2605 in order to clean the filter 2603 . This optional step can be repeated multiple times to provide the desired level of cleanliness of the filter 2603 . While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments. Variations of the embodiments described above may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.

The present invention relates to methods and systems for microfluidic DNA sample preparation. More specifically, embodiments of the present invention relate to methods and systems for the isolation of DNA from patient samples on a microfluidic device and use of the DNA for downstream processing, such as performing amplification reactions and thermal melt analysis on the microfluidic device.

FIELD OF THE INVENTION The present invention relates generally to improvements in semiconductor processing equipment. More particularly, the invention relates to methods and apparatus for clamping and shielding the edge of a substrate with minimal edge exclusion. BACKGROUND OF THE RELATED ART The fabrication of semiconductor devices on substrates typically requires the deposition of multiple metal, dielectric and semiconductive layers on the surface of substrates. These layers are typically deposited onto substrates in vacuum processing chambers. Some processing operations may require the deposition of additional layers while others may require the etching, or partial removal, of a previously deposited film layer. One commonly used vacuum deposition process is physical vapor deposition (PVD), also referred to as sputtering. In a typical PVD process, a target comprised of the desired deposition material is exposed to a plasma and bombarded by ions from the plasma. This bombardment causes atoms or larger particles to be sputtered from the target and deposited on the substrate being processed. Typically in PVD processes, the geometry of the chamber and the spacing of the target from the substrate being processed is important in order to control the even distribution of the target material onto the substrate. During processing, a substrate support member, often referred to as a pedestal, susceptor, or heater, is disposed in the processing chamber to support the substrate. A clamp ring is typically supported in the chamber above the support member on a shield. When a substrate is introduced into the chamber and supported on the support member, the support member and substrate are moved in the chamber relative to the clamp ring to pick up the clamp ring so that the clamp ring contacts the edge of the substrate and holds the substrate on the support member. As a result of the contact of the clamp ring with the edge of the substrate, the clamp ring shields the edge of the substrate from deposition material, thereby minimizing the usable area on the surface of the substrate. Clamp rings have been provided having a seat portion which engages the top surface of the substrate and an overhanging roof portion which does not contact the top portion of the substrate. The purpose of the roof portion in some applications is to shield the edge of the substrate from deposition. The roof is typically spaced from the upper surface of the substrate to prevent deposition material from being deposited at points where the clamp ring contacts the substrate. If deposition material deposits at these contact points, the substrate can adhere to the clamp ring following deposition which can lead to other difficulties including particle generation or even system shut down to remove the substrate. Clamp rings are generally formed as a continuous annular shaped member or an interrupted metal ring. As shown in FIG. 2, part of the ring 56 engages the substrate surface and exerts a downward force on the top, outer edge of the substrate 12 which is positioned on the support member. The weight of the clamp ring 30 holds the substrate in position for processing and assists in preventing substrate warpage. The fact that the clamp ring contacts the top surface of the substrate presents several problems. First, as previously mentioned, the clamp ring is likely to receive material deposits thereon as deposition processes are performed. This can cause adherence of the substrate to the clamp ring. Such adherence can hinder the removal of the substrate from the chamber following processing. Secondly, the clamp ring seat or contacting portion 56 shields a portion of the outer perimeter of the substrate surface. This reduces the useable surface area of the substrate on which electronic devices may be formed. This problem is generally referred to as edge exclusion. Much effort has been directed at developing clamp rings that shield the edge of the substrate and control or prevent sticking of substrates to the clamp ring without the loss of excess usable surface area on the substrate. Typically, clamp rings adequately secure the substrate to the support member, but achieve this holding force at the expense of the outer perimeter of the substrate. The trend in metallization is to provide as much coverage on the substrate surface as possible. This can be seen in full coverage deposition systems which do not utilize clamp rings or shadow rings during deposition. Further, the trend is to utilize copper as the material of choice in metallization and electroplating as the process of choice to deposit copper. However, copper deposited on the beveled edge of a substrate tends to flake or peel off during chemical mechanical polishing. As a result, edge exclusion has continued to be a requirement of some deposition schemes. As shown in FIG. 2, one common approach to edge exclusion has involved extending the clamp ring across the gap between the edge of the substrate and the edge of the support member and forming a lip or seat extending over the edge of the substrate. Attempts to minimize loss of usable surface area have also required moving the inner terminus of the clamp ring lip which overhangs the edge of the substrate outwardly to more closely approach the edge of the substrate. To maintain a good aspect ratio (ratio of lip overhang width to height above the substrate) to minimize loss of usable surface area on the substrate has proven difficult. One successful approach in this regard is disclosed in U.S. Pat. No. 5,810,931 which is assigned to the assignee of the present invention and incorporated herein by reference. Therefore, it would be desirable to provide a clamp ring which minimizes edge exclusion (maximizes die area) and also prevents copper (or other) metal deposition on the substrate backside and on the substrate bevel. SUMMARY OF THE INVENTION The present invention generally provides a clamp ring having a tapered seat design to secure the substrate to a supporting surface. The tapered surface of the clamp ring preferably aligns the clamp ring and the substrate to each other as well as to the supporting surface. In one aspect of the invention, the clamp ring includes a lower tapered surface which rests on an edge of a substrate, such as a beveled edge of a substrate, during processing. The upper surface of the clamp ring forms an inner lip of the clamp ring which overhangs a portion of the substrate surface above the plane of contact between the clamp ring and the substrate edge. In another aspect of the invention, the lower tapered surface of the clamp ring aligns the substrate on the support member as the clamp ring is lifted to engage the clamp ring. Any misalignment of the substrate on the support member can be corrected by lateral movement of the substrate as the substrate comes into contact with the lower tapered surface of the clamp ring. The lower tapered surface of the clamp ring is adapted to rest on the edge of the substrate and acts as a hard stop for any material deposition beyond the diameter of this plane of contact, thereby preventing edge and backside deposition of material on the substrate. BRIEF DESCRIPTION OF THE DRAWINGS The above recited features and advantages of the present invention are understood with better clarity and are best understood by reference to the following detailed description when taken in conjunction with the appended drawings. It is to be noted, however, that the appended drawings illustrate only one typical embodiment of the invention and are therefore not considered limiting of its scope, for the invention may admit to other equally affective embodiments. FIG. 1 is a side view, partially in section of a PVD substrate processing chamber system employing concepts of the present invention. FIG. 2 is a partial cross sectional view showing a typical prior art clamp ring. FIG. 3 is a partial cross sectional view showing one embodiment of a clamp ring of the invention. FIG. 4 is a partial sectional view of an another embodiment of the invention. FIG. 5 is a substantially bottom perspective view of a clamp ring of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A clamp ring according to the present invention generally provides a tapered lower surface at its inner terminus which is adapted to contact the outer edge of a substrate to prevent deposition material from being deposited on the edge and backside of a substrate and on the adjacent surfaces of a substrate support member. The clamp ring of the invention also provides improved edge exclusion and prevents the formation of a bridging layer between the clamp ring and the substrate. The invention is useful in deposition chambers for semiconductor device manufacture, such as PVD or chemical vapor deposition (CVD) chambers. The system will be described in more detail below in a typical PVD chamber for depositing a metal film, such as copper (Cu), on a substrate. While this preferred embodiment is described as an annular member, the shape is not limiting of the scope of the invention. FIG. 1 is a simplified sectional view of a conventional PVD chamber 20 having one embodiment of a clamp ring 30 of the invention supported in the upper portion of the chamber 20 . The chamber 20 generally includes a chamber enclosure wall 24 having at least one gas inlet 27 and an exhaust outlet 28 connected to a vacuum pumping system (not shown). A substrate support member 26 is disposed at the lower end of chamber and a target 22 is received at the upper end of the chamber. Target 22 is electrically isolated from the enclosure wall 24 and the enclosure wall is preferably grounded. A negative voltage is applied to the target 22 with respect to the enclosure wall 24 to generate a plasma in the chamber. A shield 40 is disposed within the chamber 20 and includes an annular upturned wall 41 on which the clamp ring 30 may be suspended over a substrate support member 26 when the support member 26 is retracted downwardly in the chamber as shown in FIG. 1 . In preparation for receiving a substrate into the chamber, the substrate support member 26 is lowered by a drive mechanism 42 to a position well below the clamp ring 30 . The bottom of support member 26 approaches a pin positioning platform 36 when in its lowered position. Support member 26 includes three or more vertical bores (not shown) each of which contains a vertically slidable pin 34 . When the support member 26 is in the lowered position, the bottom tip of each pin 34 rests on the platform 36 , and the upper tip of each pin protrudes above the upper surface of the support member 26 . The upper tips of the pins define a plane generally parallel to the upper surface of the support member 26 for receipt of a substrate to be processed. A conventional robot arm (not shown) carries a substrate 12 into the chamber 20 and places the substrate above the upper tips of pins 34 . A lift mechanism 43 moves the pin platform upwardly to place the pins against the under side of the substrate and to lift the substrate off the robot arm. The robot blade (not shown) retracts from the chamber 20 and the lift mechanism raises the support member and the pins slide downward through the support member 26 to position the substrate thereon. The lift mechanism continues to raise the support member 26 so that the periphery of the substrate contacts the inner portion of the annular clamp ring 30 which is resting on the upturned wall portion 41 . FIG. 3 is a partial cross sectional view of one embodiment of a clamp ring 30 and the edge of a substrate 12 . The clamp ring generally includes an upper roof portion 54 which extends partially over and above the upper surface of the substrate 12 to provide shielding of the contact point between the clamp ring and the edge of the substrate and an outer flange portion 50 . In one embodiment, at least a portion of the lower surface of the clamp ring 30 has a generally flat tapered surface 58 to contact a substrate. Alternatively, the surface 58 may be concave or convex. The tapered surface 58 engages the beveled edge 57 or other outer edge of substrate 12 as the clamp ring 30 engages the substrate on relative movement between the substrate and the clamp ring in the chamber. The tapered surface is preferably disposed at an angle comparable to the angled edge of a substrate, generally between about 5 and 85 degrees from the longitudinal axis of the clamp ring. The tapered surface 58 is preferably disposed at an angle which would allow the clamp ring to rest at least partially on the edge of the substrate to hold the substrate in position for processing. The substrate 12 supports the clamp ring 30 as the substrate support member is moved through the clamp ring on its travel in the chamber. Preferably, the clamp ring is supported by the beveled edge of substrate 12 uniformly about its circumference and stabilizes the substrate position relative to the support member and the clamp ring. The clamp ring 30 is heavy enough to prevent the clamp ring and/or the substrate from sliding across the surface of the support member 26 once the clamp ring engages the substrate and is supported by its own weight on the substrate. As the substrate moves through the clamp ring, any lateral offset of the substrate is eliminated because the angled surface of the clamp ring urges the substrate into alignment on the support member and within the inner diameter of the clamp ring. The tapered surface of the clamp ring thereby reduces the mechanical tolerances, i.e., variations in substrate size, which must be taken into account when defining the inner diameter of the clamp ring. While the tapered surface is shown as a generally flat surface, it is contemplated by the present invention that the surface could be concave or convex. Once clamp ring 30 is positioned on the substrate, the PVD process is started. The tapered surface 58 provides minimal surface area exclusion on the substrate during the deposition process. The tapered surface 58 also forms a solid barrier or stop to prevent vapor or particle escape from the support member 26 area during deposition. When the process is complete, the processed substrate 12 is removed from chamber 20 by a reversal of the process steps previously described. As described previously, any premature contact between the edge 57 of a substrate 12 and the tapered edge surface 58 of clamp ring 30 of the invention as the substrate 12 is raised into processing position by the support member, results in lateral movement of the substrate 12 along the top surface of the support member into an aligned position. This aligning movement can continue until the opposite side of the tapered edge 58 also contacts the opposite side bevel edge 57 of the substrate 12 . Thus, the clamp ring 30 of the invention is self aligning with the substrate 12 . FIG. 4 shows an alternative embodiment of a clamp ring of the invention. The lower surface of the clamp ring may include an angled recess 55 which defines a generally flat tapered surface 58 and a generally flat lower roof surface 59 disposed over the substrate in a manner generally parallel to the upper surface of a substrate disposed on the support member 26 which provides a roof aspect ratio which can be proportioned to provide good edge exclusion while also preventing sticking of the clamp ring to the substrate. A tapered seating surface 58 is provided to contact the edge of the substrate similar to the embodiment shown in FIG. 3 . However; the plane of the roof portion disposed inwardly of the seating portion is generally disposed parallel with the substrate surface. A roof aspect ratio (height:width) can be selected to minimize edge exclusion and/or deposition at the contact area between the clamp ring and the substrate. In addition, the generally parallel lower surface could be stepped to provide an effective roof aspect ratio which is greater than a generally planar lower surface. FIG. 5 is a substantially bottom perspective view of the clamp ring showing the tapered surface 58 and the lower roof surface 59 which define the angled recess 55 . The clamp ring is preferably made of a compatible material such as aluminum, ceramics such as aluminum oxide or alumina, quartz, and the like. Other materials may be known or become known in the art and may be used as well. The clamp ring of the present invention may be used in PVD, CVD, etch or any other processing system to improve edge exclusion. Such systems typically include a chamber and a substrate support pedestal which lifts a substrate vertically to engage a clamp ring in accordance with the concepts of the invention. Once engaged, the clamp ring seals the bevel edge surface of the substrate and maintains the position of the substrate during processing. While the forgoing is directed to the preferred embodiment of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims which follow.

A method and apparatus is provided for clamping and shielding the edge of a substrate useful in electronic device fabrication. A shadow ring is formed by an inward radial extension of the top surface of a generally annular shaped clamp ring. The shadow ring portion overhangs but does not contact the top surface of a substrate being processed. A smoothly tapered substrate contact surface extending from the outer diametrical extent of the shadow ring bottom surface to the bottom surface of the clamp ring is sized and adapted to engage the outer edge of a substrate. The substrate contact surface aligns the clamp ring to a substrate support member and a substrate to the substrate support member and the clamp ring as the substrate is lifted vertically.

FIELD OF THE INVENTION [0001] The present invention is directed at a toughening mechanism for improving the properties and performance of weld-type overlays. The toughness of the weld-type overlay is improved by controlling the thermal contraction of the weld overlay during cooling. The increased toughness weld-type overlays of the present invention may be utilized in many application including hardfacing, wear/overlay plate, as well as the rebuild and repair of metal parts. BACKGROUND OF THE INVENTION [0002] Often with conventional materials, there is an inverse relationship between hardness and toughness. Generally, as the hardness of the material increases there will be a corresponding, though not necessarily proportional, decrease in the toughness of the material. On reason for this inverse relationship is because the mechanism of dislocation movement has a significant effect on both the hardness and the toughness of a conventional material. When defects are introduced into a material, the defects may tie-up dislocations, thereby preventing the material from yielding. This mechanism makes the material both harder and stronger. Conversely, removing defects from a material allows dislocations to move freely on their slip plane and slip direction producing a greater degree of ductility. From a general standpoint, resistance to cracking (i.e. toughness) will be determined by the material's ductility because stress concentrations in front of a crack tip will create a plastic zone which blunts the crack tip, reducing the stress concentration factor, thus preventing growth of the crack. [0003] While the thermal spray coatings industry is a mature industry and the application of a high performance coatings have long been used to dramatically improve the lifetime of a part, there are many military and industrial applications for which a thermal spray coatings approach is not sufficient to solve wear problems. Problematic applications often involve heavy loads, high stress point loads, heavy impact, and gouging abrasion of the coated part. Additionally, while thermal spray may be used for limited cases in the rebuild and repair of parts, weld on techniques will generally be necessary. [0004] Accordingly, it is an object of the present invention to provide the most efficient balance of hardness and toughness in a metallic coating, so that, in a given application, both parameters may be uniquely optimized to improve the lifetime of a part to both wear and impact type phenomena. SUMMARY OF THE INVENTION [0005] In a first embodiment the present invention is directed at a method for forming a metallic overlay comprising supplying a metal substrate with a thermal expansion coefficient “X”, supplying a metal alloy which has a thermal expansion coefficient “Y”, wherein Y>X, melting said metal alloy and applying said metallic alloy to said metal substrate to form an alloy/substrate interface, forming metallurgical bonds between said metallic alloy and said substrate at said alloy/substrate interface, and causing said alloy to shrink while said alloy is constrained at said alloy/substrate interface thereby developing a residual compressive stress in said metallic alloy. [0006] In a second embodiment the present invention is directed at a method for forming a metallic overlay comprising supplying a metal substrate with a thermal expansion coefficient “X”, supplying a metal alloy which has a thermal expansion coefficient “Y”, wherein Y>X and wherein said metal alloy has a yield strength “Z”, melting said metal alloy and applying said metallic alloy to said metal substrate to form an alloy/substrate interface, forming metallurgical bonds between said metallic alloy and said substrate at said alloy/substrate interface, and causing said alloy to shrink while said alloy is constrained at said alloy/substrate interface thereby developing a residual compressive stress in said metallic alloy, wherein said compressive stress does not exceed the yield strength “Z”. [0007] In a third embodiment the present invention is directed at a method for forming a metallic overlay comprising supplying a metal substrate with a thermal expansion coefficient “X”, supplying a metal alloy which has a thermal expansion coefficient “Y”, wherein Y>X and wherein said metal alloy has a yield strength “Z”, melting said metal alloy and applying said metallic alloy to said metal substrate to form an alloy/substrate interface, forming metallurgical bonds between said metallic alloy and said substrate at said alloy/substrate interface, and causing said alloy to shrink while said alloy is constrained at said alloy/substrate interface thereby developing a residual compressive stress in said metallic alloy, wherein said compressive stress does not exceed the yield strength “Z” and wherein said metal alloy has a hardness of greater than about 850 kg/mm 2 . [0008] In yet another embodiment the present invention is directed at a method for forming a metallic overlay comprising supplying a metal substrate, supplying a metal alloy, melting said metal alloy and applying said metallic alloy to said metal substrate to form an alloy/substrate interface, forming metallurgical bonds between said metallic alloy and said substrate at said alloy/substrate interface, causing said alloy to cool to provide said alloy with a fracture toughness greater than 200 MPa m 1/2 and a hardness greater than 5 GPa. BRIEF DESCRIPTION OF THE DRAWINGS [0009] An understanding of the invention herein, including objects, features, and advantages is provided by a description of specific exemplary embodiments thereof, which description should be read and understood in conjunction with the accompanying figures, wherein [0010] FIG. 1 shows photographs of an arc melted ingot of Alloy A before (on the left) and after (on the right) being hit with a moderate blow from a ball peen hammer; [0011] FIG. 2 is a plot of thermal expansion for high velocity oxy-fuel coupons of Alloy A, Alloy B, Alloy C, and Alloy D; [0012] FIG. 3 is a plot of thermal expansion of a coupon of Alloy A up to a temperature of 1000° C., both of an as-sprayed sample and of a fully crystallized sample; and [0013] FIG. 4 is a plot of toughness versus hardness showing the hardness/toughness of Alloy C compared to published results for exemplary iron alloys, aluminum alloys, nickel alloys, carbides, nitrides, and oxides. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0014] The present invention is a method of providing a metallic overlay to a substrate that has improved toughness. The method involves a mechanism of developing compressive stresses in the metal material after cooling (residual compressive stress). The induced residual compressive stress due to shrinkage both prevents cracks from forming and acts to close the tip of any cracks that form. By preventing or mitigating cracks in the metallic overlay it is possible to significantly reduce the stress concentration factor experienced at the crack tips. [0015] As used herein, the tem “weld overlay” refers to a metallic material that has been applied to a substrate in an at least partially molten state. Furthermore, the term weld overlay contemplates a fused interface between the metallic material and the substrate, such that there is at least partial metallurgical bonding between the metallic material and the substrate. Metallurgical bonding includes a chemical bonding interaction forming metallic-type chemical bonds between the metallic material and the substrate. [0016] Accordingly, a weld overlay may include, but is not limited to metallic material applied in a welding process, a thermal spray metal coating, in which a molten or semi-molten metal is sprayed onto a substrate, or a fused coating in which a metallic coating is heated and caused to fuse to the substrate. Various other coating types and methods will be understood in which a metallic material is at least partially fused to a substrate from a molten or semi-molten state thereby forming metallurgical bonds with the substrate. [0017] Similarly, it should be understood that weld material refers to any metallic material that is applied in a manner contemplated hereinabove and/or applied forming metallurgical bonds with a substrate or base consistent with the present invention. Generally these metallic materials may be classified as glass forming metallic alloys. Most especially, suitable metallic glasses may be iron based glass forming alloys. These suitable alloys exhibit high hardness and yield strength and will have the ability to form glasses at high cooling rates. However, actual glass formation is not a priori since there are cases where the glass forming region is just missed during solidification but a high level of undercooling is achieved. This undercooling can provide a large driving force to aid in the rapid transformation to a nanoscale structure. Exemplary compositions could include any base metal with sufficiently high glass forming ability and sufficiently high thermal expansion. [0018] The present invention recognizes that when, e.g., glass forming alloys are welded they can be made to experience greater contraction on cooling as compared to a conventional steel substrate. During welding, intricate mixing occurs between the weld material and the base metal, and a full, or at least partial, metallurgical bond may be formed from the liquid melt and may be subsequently maintained during cooling. As the weld material cools it shrinks in all directions but it is constrained in at least one direction by the intimate contact/metallurgical bonding with the base metal. Therefore, as the weld deposit is cooled it contracts to a higher degree than the base metal/substrate and, therefore, solidifies into a state having high compressive residual stress. This favorable residual stress prevents cracks from forming and/or propagating in the weld material. In addition, these built up and retained compressive stresses inhibit the formation of cracks in the weld material, and thereby increase the toughness of the weld material. [0019] The development of residual stress as disclosed herein has not been observed to occur in conventional metals to the same degree. When conventional weld material solidifies, if there are large differences in coefficient of thermal expansion between the weld material and the substrate large localized stresses may arise. If these localized stresses exceed the yield strength of the weld material plastic flow of the material may occur which acts to release or relieve the residual stress. If the plasticity or total elongation of the weld material is exceeded in a localized area, crack formation may be initiated. [0020] In addition to being able to form high residual compressive stress, the present invention utilizes the unique ability of glass forming alloys to retain such residual stress upon solidification. One aspect of this is the high yield strengths found in this class of materials. For example, measured yield strengths for iron based glass forming alloys can be as high as 3000 MPa at room temperature and as high as 1800 MPa at 700° C. By comparison, it should be noted that “Ultra High Strength Steels” may generally have room temperature yield strengths in the 1380-1520 MPa range. At 700° C. the above alloy exhibits a higher yield strength than so called ultra high strength steels present at room temperature. The higher yield strengths of iron based glasses support the understanding that high residual compressive stress is maintained in the weld deposits, but the stress does not exceed the yield strength of the weld material, i.e. the stress interacts in the elastic range of the material. Utilizing these findings, coatings, welds, etc. can be provided in which both plastic deformation and cracking phenomena may be avoided and high residual compressive stress is maintained. [0021] According to the present invention a metallic glass may be deposited on a substrate, for example as a weld or thermal spray coating. Using such techniques, the metallic glass is deposited in a molten or semi-molten state. The heat of the metallic glass being deposited and/or additional processing conditions may cause at least a portion of the surface of the substrate to achieve a molten or semi-molten state as well. Desirably the metallic glass being deposited will at least partially fuse to the substrate, forming metallurgical bonds between the metallic glass and the substrate. As the metallic glass cools from the as-applied molten or semi-molten state it experiences thermal shrinkage that is relatively high. The key is that the thermal expansion of the referenced metallic glass has a higher thermal expansion coefficient than the base substrate material, preferably at least about 15.0% higher. The metallurgical bonding between the substrate and the metallic glass restricts the shrinkage of the metallic glass along the interface thereof. As a result, high compressive stresses are induced in the metallic glass. The overall effect may be somewhat analogous to shot peening or hammer forging, although the mechanism are distinguishable. [0022] As alluded to above, the present invention is susceptible to use in a variety of approaches involving weld processing, or similar processing involving the formation of metallurgical bonds between, preferably, a glass forming alloy and a substrate. Suitable processes may include Plasma Transferred Arc (PTA) welding, Metal Inert Gas (MIG) welding, Laser Engineered Net Shape (LENS), Shielded Metal Arc Welding (SMAW), Powder Welding, and Gas Tungsten Arc Welding (GTAW). These exemplary processes may utilize a powder feedstock, a flexible wire feedstock, or a solid wire feedstock. However, the form of the feedstock or the exact process used is not a limiting aspect for this invention. [0023] The invention herein accordingly pertains to improved toughness of a weld overlay. In that regard, it is worth noting that the hardness of the weld overlay will be dependant on a variety of factors including the microstructure scale, the level of supersaturation of alloying elements, and resistance of specific grain boundary pairs to resist grain boundary sliding and grain boundary rotation. EXPERIMENTAL EXAMPLES [0024] Four experimental alloys were produced having the compositions detailed in Table 1 using generally conventional alloying techniques. The metallic alloys were provided as cored wire having a diameter of {fraction (1/16)}″. The cored wire of the various alloys were processed using a MIG (metal inert gas) welding apparatus operating at 32V and 250A with a welding gas shield consisting of 98% Ar-2% O 2 to produce sample hardfacing deposits which were deposited onto various plain carbon and alloy steel substrates. TABLE 1 Alloy Designations and Compositions. Alloys Compositions (Wt %) Alloy A 78.1 Fe, 9.2 Cr, 4.3 Mo, 4.1 B, 1.3 C, 0.6 Si, and 2.4 Al Alloy B 65.9 Fe, 25.3 Cr, 1.0 Mo, 1.8 W, 3.5 B, 1.2 C, 0.5 Si, 0.8 Mn Alloy C 64.9 Fe, 26.0 Cr, 1.0 Mo, 1.4 W, 3.6 B, 1.2 C, 1.0 Si, 0.8 Mn Alloy D 68.0 Fe, 23.2 Cr, 1.2 Mo, 1.5 W, 3.6 B, 0.9 C, 0.7 Si, 0.8 Mn [0025] As a first experimental test, the hardness of welds produced using Alloy B and Alloy C were determined using Rockwell C hardness testing. Welds produced using wire stock from Alloy B and Alloy C were found to have unexpectedly high hardnesses of R c =62 and R c =65, respectively. Additionally, Alloy C and Alloy D were tested to determine the Vickers hardness. As with the Rockwell C hardness of Alloy B and Alloy C, the Vickers hardness of weld deposits formed from Alloy C and Alloy D proved unexpectedly high, exhibiting values of 950 kg/mm 2 and of 1100 kg/mm 2 respectively. [0026] The toughness of the alloys was experimentally evaluated using a hammer or hammer and chisel to apply direct blows to the substrate that had been hardfaced with weld deposits of the experimental alloys. Generally, it had previously been observed that alloys having the compositions detailed in Table 1 have very low toughness in ingot form. For example, one moderate blow from a ball peen hammer may often cause the ingots to crack apart. Such a typical result is shown in FIG. 1 , in which an ingot of Alloy A, formed by arc-melting, is shown before (on the left) and after (on the right) being stricken with a moderate blow from a ball peen hammer. In contrast to the expected result, weld deposits of the experimental alloys exhibit much higher toughness. In experimental evaluation, repeated hammer strikes to a weld-deposit hardface coating of the experimental alloys failed to produce any observable cracking of the weld deposits. Furthermore, repeated (>50) blows with a hammer and chisel resulted in only very small amounts of material being removed from the weld, at most much less than one gram. During testing, 4 different tool steel chisels were flattened and repeatedly sharpened and then reflattened as a result of striking the weld material. [0027] In addition to the hammer and chisel tests, which were remarkable, a sample cross section of an Alloy C weld deposit was tested for toughness using the Palmqvist Technique. During the Palmqvist testing, the indentation load was initially set to be 2 Kg, and was subsequently increased up to a 90 Kg load. No cracking was observed in the weld deposit even up to the maximum testing load of 90 Kg. Since no cracking was observed in the Alloy weld, it was not possible to obtain a numerical measure of toughness using the Palmqvist technique. However, it may still be possible to use the Palmqvist technique to estimate a lower limit to the fracture toughness by assuming a mean radial crack length on the general order of 10 −7 m to 10 −8 m, which is below the resolution of an optical microscope (10 −6 m). Using this assumption, the estimated lower limit of fracture toughness of the Alloy C weld deposit would be in the range of 22 to 70 MPam 1/2 . [0028] By way of comparison, relevant literature, for example D. K. Shetty, I. G. Wright, P. N. Mincer and A. H. Clauer, J. Mater. Sci. 20, 1873, (1985), has revealed that cemented tungsten carbide begins cracking during Palmqvist testing at much smaller indentations loads, approximately on the order of 2.5 Kg. Also, the literature indicates that the expected mean radial crack length for cemented tungsten carbides at an applied 90 Kg load could be estimated to be approximately 1000 microns. It should be noted that the Palmqvist method of measuring Fracture Toughness is well established in the weld on hardfacing and sintered carbide industries and is the industry standard to measure toughness. Based on previous studies, the Palmqvist toughness can be correlated fairly accurately to the plain strain fracture toughness (K 1c ). See, for example, D. K. Shetty, I. G. Wright, P. N. Mincer and A. H. Clauer, J. Mater. Sci. 20, 1873, (1985); and G. R. Anstis, P. Chantikui, B. R. Lawn and D. B. Marshall, J. Am Ceram. Soc. 64, 533, (1981). [0029] Referring to FIG. 4 the toughness versus hardness for a variety of materials including iron alloys, aluminum alloys, nickel alloys, carbides, nitrides, and oxides is shown. As shown, the general inverse relationship between hardness and toughness is observed. On the plot, it can be seen that the Alloy C weld (indicated as DAR), occupies a new material regime, with novel combinations of toughness and hardness. As can be seen in FIG. 4 , Alloy C not only exhibits uniquely high fracture toughness, but the high fracture toughness is achieved without an attendant decrease in hardness. Table 2 through Table 10 below present the data of FIG. 4 in tabular format. TABLE 2 Hardness and Fracture Toughness for Selected Oxides. Hardness Fracture Oxide Compound (GPa) (MPa(m)1/2) Al2O3 26 2 Al2O3 19 6 Al2O3 23 4 MgO 8 2.5 MgAlO4 18 1.9 MgAlO4 14 2.4 Mullite 15 3 ThO2 10 1.6 Y2O3 8 1.5 ZrO2 15 3 ZrO2 12 3.6 ZrO2 7.4 9 TiO2 7.4 1.4 TiO2 10.5 1.9 [0030] TABLE 3 Hardness and Fracture Toughness for Selected Carbides. Hardness Fracture Carbides (GPa) (MPa(m)1/2) SiC 26 6 SiC 36 3 SiC 27 4 SiC 19.3 4 SiC 21.1 3.1 TiC 28 3 TiC 16 5 BC 72.2 6 [0031] TABLE 4 Hardness and Fracture Toughness for Selected Nitrides. Hardness Fracture Nitrides (GPa) (MPa(m)1/2) Si3N4 30 3 Si3N4 17 10 Si3N4 14.1 4.9 [0032] TABLE 5 Hardness and Fracture Toughness for Selected Tungsten Carbides. Hardness Fracture WC—Co (GPa) (MPa(m)1/2) WC—Co 16.72 9.4 WC—Co 16.33 9.3 WC—Co 14.93 9.9 WC—Co 11.77 13.1 WC—Co 16.87 7.7 WC—Co 15.06 8.1 WC—Co 16.75 9.6 WC—Co 19.61 8.9 WC—Co 14.09 9.5 WC—Co 14.27 9.3 WC—Co 15.3 8.2 WC—Co 13.3 10 WC—Co 15.7 7.6 WC—Co 17.46 6.4 WC—Co 19.84 5.1 WC—Co 13.29 9.9 WC—Co 16.84 6.9 WC—Co 15.58 7.8 WC—Co 12.74 11.6 WC—Co 12.33 12.2 WC—Co 11.37 14.5 WC—Co 11.46 14.1 WC—Co 10.84 15.5 WC—Co 10.92 15.2 WC—Co 11.86 13.3 WC—Co 11.96 12.9 WC—Co 11.045 14.5 WC—Co 10.09 17.1 WC—Co 13.2 16 [0033] TABLE 6 Hardness and Fracture Toughness for Selected Titanium Alloys. Hardness Fracture Ti Alloy (GPa) (MPa(m)1/2) Ti—5Al—2.5Sn 3.136 76.93 Ti—6Al—2Cb—1Ta—1Mo 2.94 98.91 Ti—8Al—1Mo—1V 3.43 65.94 Ti—6Al—4V 3.626 65.94 Ti—6Al—6V—2Sn 3.332 60.445 Ti—6Al—6V—2Sn 4.312 24.178 Ti—6Al2Sn4Zr—6Mo 3.43 36.267 Ti—6Al2Sn4Zr—6Mo 3.92 24.178 Ti—13V—11Cr—3Al 3.332 87.92 Ti—13V—11Cr—3Al 4.214 38.465 [0034] TABLE 7 Hardness and Fracture Toughness for Selected Aluminum Alloys. Hardness Fracture Al Alloys (GPa) (MPa(m)1/2) 1.323 23.2 0.931 29.1 1.2054 32.3 1.47 22.5 2014 1.323 18.683 2024 1.176 28.574 2219 1.274 36.267 5086 0.7056 49.455 6061 0.931 28.574 7075 1.47 20.881 [0035] TABLE 8 Hardness and Fracture Toughness for Selected Steel Alloys. Hardness Fracture Steel Alloy (GPa) (MPa(m)1/2) 3.724 109.9 4.214 74.732 5.39 52.752 4.9 48.356 4.606 71.435 2.2442 64.841 4.802 71.435 [0036] TABLE 9 Hardness and Fracture Toughness for Selected Nickel Alloys. Hardness Fracture Ni Alloy (GPa) (MPa(m)1/2) 5.096 38.465 5.488 29.673 5.194 76.93 5.488 60.445 5.096 46.158 4.508 65.94 5.292 32.97 4.606 65.94 4.214 82.425 3.528 131.88 4.704 49.455 5.39 74.732 5.39 79.128 5.8016 49.455 0.441 155 0.4704 120 0.4998 80 0.4214 125 [0037] TABLE 10 Hardness and Fracture Toughness for Selected DAR Alloys. Hardness Fracture DAR Alloy (GPa) (MPa(m)1/2) DAR 8.3 22.28413 8.3 70.46859 8.3 222.8413 8.3 704.6859 [0038] Additional testing of the experimental alloys included differential scanning calorimetry (DSC) of Alloy B. The DSC analysis indicated that the alloy contained at least a small fraction of glass. The presence of the glass fraction was indicated by a peak at approximately 615° C., which is the temperature of the metallic glass transition for an alloy of the tested composition. Both Alloy C and Alloy D were also designed to have an increased glass forming ability compared to Alloy B. [0039] The experimental examples discussed above indicate that the MIG weld-deposited alloys consistent with the present invention have a high degree of toughness and a high level of hardness. At the time of filing, it is believed that this toughness is related to the differential thermal expansion of the weld-deposited material as compared to the substrate on which the material is deposited. This theory was based on testing of the thermal expansion of selected iron based glass forming alloys which were measured over the temperature range of 20-1000° C. The tests of thermal expansion were conducted using a Theta Industries Dilamatic II dilatometer on coupons of the alloys produced by high velocity oxy-fuel spraying. The experimentally determined thermal expansion of the alloys versus temperature is shown in FIG. 2 . In this plot, it is noted that the reduction in slope found in each alloy was verified to be the result of the volume reduction which occurs when the glass crystallizes as shown in FIG. 3 . It was noted that the beginning of the reduction in slope for each alloy corresponds to the glass crystallization temperatures for each respective alloy. [0040] Referring to FIG. 3 , a plot of the thermal expansion of the Alloy A versus temperature is shown, both for an as-sprayed test specimen and for a specimen that had been completely crystallized prior to testing. It can be seen from this plot that the completely crystallized specimen did not experience a reduction in expansion with increasing temperature because the specimen was free of glass. [0041] Based on the above experiments, it was found that the glass forming steel alloys exhibit relatively high thermal expansions. The test results of thermal expansion coefficients for the experimental alloys compared to several commercial steel alloys are listed in Table 11. It can be seen that these specialized iron based glass forming alloys have much higher thermal expansion coefficients than many conventional iron based alloys, as reported in William D. Callister, Jr., Materials Science and Engineering , John Wiley & Sons, New York, 1994. TABLE 11 Coefficient of Thermal Expansion for Various Alloys (100 to 500° C.). Alloy CTE (ppm/° C.) Alloy A 14.34 Alloy B 14.84 Alloy C 14.73 Alloy D 14.75 Iron 11.8 1020 steel 11.7 1080 steel 11.0 410 stainless steel 9.9

A method is provided for forming a metallic overlay having enhanced toughness. The metallic overlay may be a weld, a metallic coating, or similar application. The method includes applying a glass forming metallic alloy to a substrate while the alloy is in a molten or semi-molten state. At the interface of the metallic alloy overlay and the substrate the substrate metal becomes at least partially molten and combines with the alloy to form metallurgical bonds. When the metallic alloy cools it experiences a high relative degree of thermal contraction. The metallurgical bonds between the substrate and the alloy constrain the contraction of the alloy at the interface with the substrate. This results in the inducement of compressive stresses in the metallic alloy overlay. The induced compressive stresses inhibit the formation of cracks in the overlay and/or mitigation of the effects of any cracks in the overlay.

CROSS-REFERENCE TO RELATED APPLICATION This application is related to and claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application 60/088,754, filed Jun. 10, 1998. BACKGROUND OF INVENTION This invention pertains to hermetically sealed, positive displacement compressors for compressing refrigerant in refrigeration systems such as air conditioners, refrigerators and the like. In particular, the invention describes a rotary compressor mechanism of the type which includes a cylinder block having a cylindrical cavity, a bearing assembly and a motor assembly driving a roller piston disposed in the cylindrical cavity. More particularly, the cylinder block includes a vane slot extending completely axially through the cylinder block to accommodate a reciprocating vane therein and the vane being urged against the roller piston. Rotary compressors are well known in the art, as exemplified by U.S. Pat. No. 4,889,475 which is assigned to assignee of the present application. Generally, the tolerances between the reciprocating vane and the slot sidewalls defining the vane slot of the cylinder block must be tightly controlled in order to optimize compressor efficiency. Proper vane clearances are necessary to allow free reciprocation of the vane in its slot and to allow sealing against discharge pressure gas blow-by therebetween. Maintaining these clearances in previous compressors often requires precision vane and/or slot machining, or select fitting of the individual vanes and cylinder blocks. A disadvantage arising from precision machining of the slot and/or vane is the associated cost of precision machining a pair of sidewalls defining the vane slot and vane. Always existent with precision machining is the immense cost associated with the act of “scrapping a part” when one of the final operations is spoiled due to a myriad of possible and easily made mistakes. A structure and method for easily providing uniform clearances between the vanes and their slots without resorting to costly and time consuming machining operations or select fitting is needed. Generally, rotary compressor assembly entails first, laboriously preparing the vane and vane slot for an introduction of the vane into the vane slot, and second, the vane is introduced into the vane slot. A disadvantage, already mentioned hereinabove, is that laboriously preparing components, through precision machining and the like, has an increased cost associated therewith. Therefore, if components, such as the vane and vane slot, required less labor and the precise relationship required between the vane and vane slot were sustained through an inventive method of assembly, this inventive method would be highly desirous. SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the prior art described above by providing a rotary compressor assembly as herein described. The present invention rotary compressor assembly is hermetically sealed and comprises a housing, a cylinder block and a bearing assembly disposed within the housing. The cylinder block and the bearing assembly define a cylindrical cavity which has a roller piston disposed therein. The rotary compressor assembly includes a motor drivingly coupled to the roller piston. The present invention rotary compressor assembly also includes the cylinder block having a vane slot extending completely axially through the cylinder block and extending radially from an outside perimeter surface of the cylinder block to the cylindrical cavity. At least a portion of the vane slot is defined by a pair of substantially parallel sidewalls and a vane is disposed in and guided by the vane slot and is urged against said roller piston. The cylinder block, of the present invention rotary compressor assembly, is in a state of circumferentially oriented stress and is fixed in that state of stress. The present invention also includes a method to assemble a rotary compressor assembly which include steps, one step being, spreading apart the sidewalls of the vane slot in the cylinder block. Another step includes inserting into the spread apart slot a gauge vane of thickness greater than the thickness of a reciprocating vane. Yet another step includes releasing the block to cause the slot sidewalls to engage the gauge vane. Remaining steps include fixing the cylinder block to hold the sidewalls substantially parallel, removing the gauge vane from the slot, and inserting the reciprocating vane in the slot, whereby a clearance is maintained between the reciprocating vane and slot sidewalls. The present invention also provides yet another method to assemble a rotary compressor assembly which includes steps, one being, inserting into the vane slot in the cylinder block the gauge vane of thickness greater than a thickness of the reciprocating vane. Another step includes closing together sidewalls of the vane slot in the cylinder block to cause the slot sidewalls to engage the gauge vane with the cylinder block. Also included are the steps of fixing the cylinder block to hold the sidewalls substantially parallel, removing the gauge vane from the slot, and inserting the reciprocating vane in the slot, whereby a clearance is maintained between the reciprocating vane and slot sidewalls. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a sectional side view of one embodiment of a compressor assembly according to the present invention, also showing the cross-over tube fluidly connecting the two discharge chambers and the compressor assembly discharge tube; FIG. 2 is an enlarged fragmentary sectional side view of the rear portion of the compressor assembly shown in FIG. 1; FIG. 3 is a sectional rear view of the compressor assembly shown in FIG. 2, taken along line 3 — 3 thereof; FIG. 4 is a sectional front view of the compressor assembly shown in FIG. 2, taken along line 4 — 4 thereof; FIG. 5 is a front view of the front main bearing of the compressor assembly shown in FIG. 1, including the outline of the cylinder block location on the axial main bearing surface; FIG. 6 is a rear view of the main bearing shown in FIG. 5; FIG. 7 is a rear view of the rear main bearing of the compressor assembly shown in FIG. 1, including the outline of the cylinder block location on the axial main bearing surface; FIG. 8 is a front view of the main bearing shown in FIG. 7; FIG. 9 is sectional side view of each of the main bearings shown in FIGS. 5 and 7, along lines 9 — 9 thereof; FIG. 10 is a fragmentary sectional side view of each of the main bearings shown in FIGS. 6 and 8, along lines 10 — 10 thereof; FIG. 11 is a front view of the common front and rear cylinder block of the compressor assembly shown in FIG. 1; FIG. 12 is a front view of the front outboard bearing of the compressor assembly shown in FIG. 1; FIG. 13 is a sectional side view of the outboard bearing of FIG. 12, along line 13 — 13 thereof; FIG. 14 is a rear view of the rear outboard bearing of the compressor assembly shown in FIG. 1; FIG. 15 is a sectional side view of the outboard bearing of FIG. 14, along line 15 — 15 thereof; FIG. 16A is a partial sectional side view of the shaft of the compressor assembly shown in FIG. 1; FIG. 16B is an enlarged sectional rear view of the shaft shown in FIG. 16A, along line 16 B— 16 B thereof; FIG. 16C is an enlarged sectional front view of the shaft shown in FIG. 16A, along line 16 C— 16 C thereof; FIG. 17A is an enlarged sectional side view of an eccentric of the compressor assembly shown in FIG. 1; FIG. 17B is a sectional end view of the eccentric shown in FIG. 17A, along line 17 B— 17 B thereof; FIG. 18 is a sectional side view of a second embodiment of a compressor assembly according to the present invention, also showing the cross-over tube fluidly connecting the two discharge chambers and the compressor assembly discharge tube; FIG. 19 is an enlarged fragmentary sectional side view of the bottom portion of the compressor assembly shown in FIG. 18; FIG. 20 is a sectional plan view of the compressor assembly shown in FIG. 19, taken along line 20 — 20 thereof; FIG. 21 is a top view of the common upper and lower cylinder block of the compressor assembly shown in FIG. 18; FIG. 22 a bottom view of the lower outboard bearing of the compressor assembly shown in FIG. 18; FIG. 23 is a sectional side view of the outboard bearing of FIG. 22, along line 23 — 23 thereof; FIG. 24 is a sectional side view of the third embodiment of a compressor assembly according to the present invention, also showing the cross-over tube fluidly connecting the two discharge chambers and the compressor assembly discharge tube; FIG. 25 is an enlarged fragmentary sectional side view of the front portion of the compressor assembly shown in FIG. 24; FIG. 26 is a sectional rear view of the compressor assembly shown in FIG. 25, taken along line 26 — 26 thereof; FIG. 27 is a sectional front view of the compressor assembly shown in FIG. 25, taken along line 27 — 27 thereof; FIG. 28 is a fragmentary perspective of a common cylinder block of the compressor assembly shown in FIG. 24, including the reed valve assembly and extended vane; FIG. 29 is a front view of the front main bearing of the compressor assembly shown in FIG. 24, including the outline of the cylinder block location on the axial main bearing surface; FIG. 30 is a rear view of the main bearing shown in FIG. 29; FIG. 31 is a rear view of the rear main bearing of the compressor assembly shown in FIG. 24, including the outline of the cylinder block location on the axial main bearing surface; FIG. 32 is a front view of the main bearing shown in FIG. 31; FIG. 33 is sectional side view of each of the main bearings shown in FIGS. 30 and 32, along lines 33 — 33 thereof; FIG. 34 is a front view of the common front and rear cylinder block of the compressor assembly shown in FIG. 24; FIG. 35 is a sectional bottom view of the cylinder block of FIG. 34, along line 35 — 35 thereof; FIG. 36 is a front view of the front outboard bearing of the compressor assembly shown in FIG. 24; FIG. 37 is a sectional side view of the outboard bearing of FIG. 36, along line 37 — 37 thereof; FIG. 38 is a sectional side view of the outboard bearing of FIG. 36, along line 38 — 38 thereof; FIG. 39 is an exploded view of the pump assembly and rear outboard bearing of the present invention shown in FIG. 24; FIG. 40 is a partial sectional side view of the shaft of the compressor assembly shown in FIG. 1; FIG. 41 is an enlarged sectional rear view of the shaft shown in FIG. 40, along line 41 — 41 thereof; FIG. 42 is an enlarged sectional front view of the shaft shown in FIG. 40, along line 42 — 42 thereof; FIG. 43 is a front perspective view of an eccentric of the compressor assembly as shown in FIG. 24; FIG. 44 is a sectional side view of the eccentric shown in FIG. 43, along line 44 — 44 thereof; FIG. 45 is a sectional end view of the eccentric shown in FIG. 44, along line 45 — 45 thereof; FIG. 46 is a sectional side view of a fourth embodiment of a compressor assembly according to the present invention, also showing the cross-over tube fluidly connecting the two discharge chambers and the compressor assembly discharge tube; FIG. 47 is a sectional side view of a fifth embodiment of a compressor assembly according to the present invention, showing the suction tube fluidly connecting a discharge of one of the compressor mechanisms to a suction port of the remaining compressor mechanism and the compressor assembly discharge tube; FIG. 48 is a sectional rear view of the compressor assembly shown in FIG. 47, taken along line 48 — 48 thereof; FIG. 49 is a sectional rear view of the compressor assembly shown in FIG. 47, taken along line 49 — 49 thereof; FIG. 50 is a simplified model of the common cylinder blocks of the compressor assemblies shown in FIGS. 1, 18 , 24 and 46 - 47 , showing an inwardly tapered vane slot; FIG. 51 is the model cylinder block of FIG. 51, showing a gauge vane therein, outward forces applied thereto and a state of circumferentially oriented tensile stress; FIG. 52 is the model cylinder block of FIG. 51, showing an operable vane slot of width “S” and the state of circumferentially oriented tensile stress preserved therein; FIG. 53 is a simplified model of the common cylinder blocks of the compressor assemblies shown in FIG. 1, 18 , 24 and 46 - 47 , and an alternative to the model cylinder block of FIG. 51, showing an outwardly tapered vane slot; FIG. 54 is the model cylinder block of FIG. 53, showing a gauge vane therein, inward forces applied thereto and a state of circumferentially oriented compressive stress; and FIG. 55 is the model cylinder block of FIG. 53, showing an operable vane slot of width “S” and the state of circumferentially oriented compressive stress preserved therein. Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention in alternative forms, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION OF THE INVENTION The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Referring to FIG. 1, there is shown twin rotary compressor assembly 10 , a first embodiment according to the present invention. Compressor assembly 10 comprises housing 12 which is itself comprised of first housing portion 14 , second, cylindrical housing portion 16 and third housing portion 18 , first and third housing portions 14 and 18 being somewhat cup shaped, second housing portion 16 interposed between housing portions 14 and 18 . Compressor assembly 10 further comprises front and rear main bearings 20 , 22 , respectively, which comprise, within housing portions 14 and 18 , respective front and rear compressor mechanisms 24 and 26 . As will be discussed further below, front main bearing 20 and rear main bearing 22 are mirror images of each other. Each of main bearings 20 , 22 may be machined from a common casting or, alternatively, from a common sintered powder metal form. Main bearings 20 and 22 are respectively provided, at their peripheries, with annular, oppositely facing control surfaces 28 and 29 . Control surfaces 28 and 29 lie in parallel planes which are perpendicular to the central axis of each main bearing. The forwardly and rearwardly facing axial surfaces of cylindrical second housing portion 16 are each provided with axial counterbore 30 concentric about the central axis of housing portion 16 and which provides annular shoulders 31 against which axial surfaces 28 , 29 abut. Shoulders 31 lie in parallel planes which are perpendicular to the central axis of cylindrical housing portion 16 and provide control surfaces for proper axial spacing and radial alignment of main bearings 20 , 22 , and ensure they fit squarely within housing portion 16 . Proper placement of main bearings 20 , 22 allows the shaft supported thereby to be properly journaled and assures proper clearances are provided between the moving components which comprise front and rear compressor mechanisms 24 , 26 . The mating axial ends of housing portions 14 , 16 and 18 are joined at the outer radial periphery of respective main bearings 20 , 22 , to which they are sealably attached, as by welding. Welding each of housing portions 14 , 16 and 18 to the main bearings separates housing 12 into three distinct internal chambers separated by the main bearings. Front chamber 32 is generally defined by inside surface 33 of housing portion 14 and forward facing axial surface 34 of main bearing 20 . Similarly, rear chamber 36 is defined by inside surface 37 of third housing portion 18 and rearward facing axial surface 38 of rear main bearing 22 . As will be discussed further below, chambers 32 and 36 contain refrigerant gas at discharge pressure, and are also referred to hereinafter as front and rear discharge chambers, respectively. Intermediate main bearings 20 and 22 and generally defined by inside cylindrical surface 39 of center housing portion 16 and surfaces 40 and 42 of front and rear main bearings 20 and 22 , respectively, is chamber 44 . Chamber 44 , as will be discussed further below, contains refrigerant gas at suction pressure, and is hereinafter referred to as suction chamber 44 . Within suction chamber 44 is disposed motor assembly 46 comprising stator 48 in surrounding relationship with rotor 50 . Shaft 52 extends through the center of rotor 50 , and is attached thereto to be driven by rotor 50 when motor assembly 46 is energized through terminals 54 , which electrically communicate the motor with an external source of power. Providing the motor in the suction chamber provides a cooler operating environment for it, promoting its efficient operation and prevents its overheating. Further, placement of the motor assembly in the relatively cool environment of the suction chamber provides for easier identification of an internal motor over-temperature condition vis-a-vis compressors having motors exposed to discharge pressure, for the temperature protection device (not shown) attached to the stator windings, which interrupts electrical current to the motor when it becomes overheated, need not be calibrated to operate in relatively narrow temperature difference ranges between discharge gas temperatures to which the motor is ordinarily exposed and the motor over-temperature point. Shaft 52 comprises large diameter central portion 56 , which extends through rotor 50 , and forwardly and rearwardly extending small diameter portions 58 and 60 , respectively, adjacent portion 56 . At the juncture of shaft portion 56 with shaft portions 58 and 60 , shaft 52 is provided with annular groove 57 in which may be disposed oil seal 59 which may be made of a material such as Teflon® or Ryton® and past which some leakage is permissible. Annular shoulder 62 is formed on the axial surface of shaft large diameter portion 56 , at its juncture with groove 57 . Thrust washer 64 is disposed about small diameter shaft portion 60 , with its forwardly and rearwardly facing axial surfaces abutting shaft shoulder 62 and forward facing axial surface 66 of hub portion 68 of rear main bearing 22 . Motor assembly 46 is arranged such that the windings of stator 48 and rotor 50 are axially offset by distance δ. Upon energization of stator 48 , rotor 50 not only rotates but is also urged rearward as it attempts to axially align its windings with those of the stator. Rotor 50 thus exerts a rearward axial force on shaft 52 which is transferred through shoulder 62 to thrust bearing 64 and opposed by main bearing 22 . In this way, axial surfaces of the eccentrics and adjacent bearings are not brought into abutment and caused to carry an axial load. Small diameter shaft portions 58 and 60 are respectively journaled in main bearing journals 70 and 72 , which extend through main bearing hub portions 74 and 68 . Front compressor mechanism 24 and rear compressor 26 are each provided with cylinder block 76 . Cylinder block 76 comprises outer peripheral surface 78 and inner cylindrical cavity 80 . Cylindrical cavity 80 extends through the width of cylinder block 76 between its forward and rearwardly facing parallel axial surfaces 82 and 84 , respectively. In front compressor mechanism 24 , cylinder block rearward surface 84 abuts forwardly facing axial surface 34 of main bearing 20 . Similarly, in rear compressor mechanism 26 , cylinder block forward surface 82 abuts rearwardly facing main bearing axial surface 38 . Thus it can be seen that cylinder blocks 76 are similarly oriented about shaft 52 in front and rear compressor mechanisms 24 , 26 . In front compressor mechanism 24 , forward cylinder block surface 82 abuts rearwardly facing axial surface 86 of front outboard bearing 88 . Outboard bearing 88 , frontmost cylinder block 76 and front main bearing 20 are attached by a plurality of bolts 90 extending through bolt holes 92 , 94 and 96 , with bolts 90 threadedly engaging main bearing bolt holes 96 . In rear compressor mechanism 26 , rearward cylinder block surface 84 abuts forwardly facing axial surface 98 of rear outboard bearing 100 . As described above, a plurality of bolts 90 attaches outboard bearing 100 , rearmost cylinder block 76 and rear main bearing 22 , extending through bolt holes 102 , 94 and 104 provided therein, threadedly engaging main bearing bolt holes 104 . Small diameter shaft portions 58 and 60 extend through outboard bearings 88 and 100 , and are supported in respective journals 106 and 108 provided therein. As will be discussed further below, front outboard bearing 88 and rear outboard bearing 100 are mirror images of one another, and may be machined together or on common tooling from identical castings or sintered powder metal forms. Shaft 52 is provided with axial bore 110 which extends completely through its length. At its rearmost end, bore 110 is provided with impeller-type pump assembly 112 of a type commonly used in the art. Pump assembly 112 draws liquid lubricant from the lowermost portion of rear discharge chamber 36 , which serves as a sump, through vertical lubricant draw conduit or tube 114 , which extends downwardly from pump assembly 112 . The lowermost portion of front discharge chamber 32 also contains a quantity of liquid lubricant, also referred to as oil, as may that of suction chamber 44 . Pump assembly 112 provides oil through bore 110 to rear compressor mechanism 26 and to front compressor mechanism 24 for lubrication thereof, as will be discussed further below. Discharge chambers 32 and 36 are in fluid communication with one another by means of external cross-over discharge conduit in the form of a tube 115 which extends axially along the outside of compressor housing 12 and, referring to FIGS. 3 and 4, extends into discharge chambers 32 and 36 to the extent that its open ends 116 are disposed above the normal height of a pool of liquid lubricant having surface level 118 . Cross-over tube 115 , as initially shown in FIG. 1 and various Figures thereafter, is an uninterrupted conduit, however, a sweat fitting or other like sealing fitting may disrupt the continuity to ease in the assembly process of the compressor assembly. Discharge pressure gas from front discharge chamber 32 is provided through cross-over tube 115 to discharge chamber 36 , wherein it joins the discharge pressure gas exhausted from rear compressor assembly 26 and is discharged from compressor assembly 10 through discharge conduit or tube 120 , which extends into the upper portion of rear discharge chamber 36 . Each pool of liquid lubricant having level 118 is maintained at approximately equal heights in both discharge chambers 32 and 36 by excess lubricant being redistributed between the two discharge chamber sumps via cross-over tube 115 as level 118 rises above the height of tube end opening 116 (FIG. 3 ). Referring again to FIG. 1, it can be seen that each compressor mechanism 24 and 26 is provided with eccentric 122 mounted on respective small diameter shaft portion 58 , 60 and disposed in cavity 80 of each cylinder block 76 . Each eccentric 122 is mounted about the axis of shaft 52 180° apart from the other to ensure proper balance. Further, counterweight 123 may be provided at opposite axial ends of rotor 50 , 180° apart, to aid in balancing compressor assembly 10 . Referring now to FIG. 4, which illustrates rear compressor mechanism 26 but which may be analogously applied to understand the structure of front compressor mechanism 24 , it can be seen that eccentric 122 is disposed about shaft portion 60 and is fixed for rotation therewith by means of set screw 124 threadedly engaged in hole 126 provided in the eccentric. Terminal point 128 of set screw 124 is received in countersink 130 provided in the surface of shaft portion 60 . With reference to FIGS. 2 and 4, it is shown that cylindrical roller piston 132 is provided about eccentric 122 , inside surface 133 of roller piston 132 in sliding contact with outer peripheral surface 134 of eccentric 122 . Further, it can be seen from FIGS. 1 and 2 that the forwardly and rearwardly facing axial surfaces of roller piston 132 are closely adjacent to the axial surfaces of the main and outboard bearings, with a maximum axial clearance preferably of about 0.0007 inch between the piston/bearing interfaces. In the known manner of operation of rotary compressors, roller piston 132 rotates on the cylindrical surface of cavity 80 in an epicyclic manner. Outer cylindrical surface 135 of roller piston 132 is in sliding contact with tip 136 of vane 138 . Vane 138 is provided in each compressor mechanism 24 , 26 , and is urged into sliding engagement with roller piston surfaces 135 by means of springs 142 which encircle depending vane posts 144 and abuts vane surfaces 146 adjacent thereto. The opposite ends of springs 142 are retained by brackets 148 which are attached to surfaces 34 and 38 of main bearings 20 and 22 by means of rivets 150 provided in holes 152 and 154 . Referring to FIGS. 2 and 4, it can be seen that vane 138 has opposite, parallel planar sides 156 and 158 , and opposite, parallel edges 160 and 162 . Edges 160 , 162 are in sliding engagement with the respective adjacent axial main and outboard bearing surfaces. Suction gases enter compressor assembly 10 through suction conduit or tube 164 (FIGS. 1, 3 ), which extends into suction chamber 44 . The outlet of suction tube 164 is covered by filter 165 in which debris carried by refrigerant returning to the compressor assembly may be captured. Filter 165 may be a wire cloth or finely meshed screen which may be spot welded over or press-fitted into the end of tube 164 . Filter 165 may be 100 mesh wire screen, comprising 100 interwoven wires of 0.007 inch diameter per inch, which would only allow particles smaller than approximately 0.003 inch to pass through to chamber 44 . Because the suction gases returning the compressor assembly are directed through suction tube 164 into chamber 44 , which provides a relatively large expansion volume, a refrigerant system incorporating the inventive compressor would not ordinarily require an in-line suction muffler external to the compressor assembly. Suction chamber 44 will contain a quantity of lubricant carried with refrigerant returning to compressor 10 , and as shown in FIG. 1 and 2, lubricant level 166 is substantially lower than lubricant levels 118 in discharge chambers 32 and 36 . Referring to FIGS. 5-8, and 10 , it can be seen that front and rear main bearings 20 , 22 are provided with suction ports 168 , 170 , respectively, which extend axially therethrough (FIG. 10 ). Normally, suction chamber lubricant level 166 is below suction ports 168 , 170 but may be above lubricant inlet bores 172 , 174 , provided in respective main bearing surfaces 40 , 42 . Bores 172 , 174 extend axially from respective surfaces 40 , 42 into web portion 175 of the main bearings, in which they terminate without projecting through to axial surfaces 34 , 38 thereof. Referring to FIG. 10, radial conduits 176 , 178 are provided in the peripheral edges of main bearings 20 , 22 to fluidly connect lubricant intake bores 172 , 174 with suction ports 168 , 170 . The peripheral openings of conduits 176 , 178 are sealed upon assembly and welding of housing portions 14 , 18 to main bearings 20 , 22 . Suction ports 168 , 170 communicate with suction port 180 in cylinder block 76 which can be seen in FIGS. 4 and 11. Like cylindrical cavity 80 , suction port 180 extends axially between the surfaces 82 and 84 of cylinder block 76 , and communicates directly with cavity 80 through suction inlet 182 . As suction gas flows from suction chamber 44 into suction port 180 through ports 168 , 170 , it may aspirate oil from chamber 44 through lubricant intake apertures 172 , 174 and bores 176 , 178 into suction port 180 , if level 166 is above the height of apertures 172 , 174 , thus scavenging oil from the suction chamber. This scavenged oil is carried by the refrigerant into cavity 80 , which comprises the compression chamber of compressor mechanisms 24 , 26 , and delivered therethrough to discharge chambers 32 , 36 . In cylinder block 76 , adjacent suction inlet 182 is a vertically oriented channel or vane slot 184 which extends the width of the cylinder block between surface 82 and surface 84 and has generally parallel side walls 186 , 188 (FIG. 11 ). Vane 138 is disposed in vane slot 184 and vertically reciprocates therein as its tip 136 follows outside surface 135 of roller piston 132 , with one of vane surfaces 156 , 158 adjacent vane slot sidewall 186 , the opposite vane surface adjacent vane slot sidewall 188 . Vane 138 may be a sintered powder metal part, the tolerances between its opposite planar surfaces 156 , 158 and its opposite edges 160 , 162 closely controlled. Cylinder block 76 may be manufactured from individually cast blanks which have been machined or they may be sintered powder metal parts. Alternatively, an axially elongate “loaf” of uniform cross section may be produced by casting, powder metal techniques or extrusion, which is then sawed into individual cylinder blocks of appropriate thickness and machined. An “off the shelf” cylinder block, including an inwardly tapered vane slot (FIG. 50 ), has a vane slot width less than the vane and requires a force being exerted, proximate to the vane slot walls, to force them apart to receive the vane. In order to provide proper clearances between vane slot sidewalls 186 a and 188 a and the adjacent vane surfaces 156 , 158 , a process of assembling a rotary compressor according to the present invention includes the steps of: forcing apart vane slot walls 186 a and 188 a slightly; providing a dummy vane or gauge vane (FIGS. 51 and 54) having generally the same shape as vane 138 except being about 0.0020 inch thicker between its opposite planar surfaces in vane slot 184 a ; allowing vane slot walls 186 a , 188 a to resiliently come into contact with the planar sides of the gauge vane; assembling the main bearing, cylinder block and outboard bearing together about the shaft/eccentric/piston assembly; placing and torquing bolts 90 to appropriate levels to compress cylinder block 76 a between the bearings, thereby establishing sufficient frictional contact between the abutting axial surfaces of the bearings and the cylinder block to hold vane slot walls 186 a , 188 a at their current spacing; and removing the gauge vane and substituting therefor vane 138 , which will have approximately 0.0020 inch clearance between one of its planar sides 156 , 158 and its adjacent vane slot sidewall. An alternative to the inwardly tapered vane slotted cylinder block, as hereinabove described, is an “off the shelf” cylinder block including an outwardly tapered vane slot (FIG. 53 ), having a vane slot width greater than the vane and requiring a force being exerted, proximate to the vane slot walls, to force them together to support the vane. A method of decreasing the width of vane slot 184 b to provide a suitable clearance between the vane 138 and vane slot 184 b may be employed. In order to provide proper clearances between vane slot sidewalls 186 b and 188 b and the adjacent vane surfaces 156 , 158 , a process of assembling a rotary compressor according to the present invention includes the steps of: providing the gauge vane having generally the same shape as vane 138 except being about 0.0020 inch thicker between its opposite planar surfaces in vane slot 184 b ; decreasing the width of the vane slot 184 b by forcing the vane slot walls 186 b and 188 b slightly together to frictionally hold the gauge vane therebetween; applying an inward force to the vane slot walls 186 b , 188 b to come into contact with the planar sides of the gauge vane; assembling the main bearing, cylinder block and outboard bearing together about the shaft/eccentric/piston assembly; placing and torquing bolts 90 to appropriate levels to compress cylinder block 76 b between the bearings, thereby establishing sufficient frictional contact between the abutting axial surfaces of the bearings and the cylinder block to hold vane slot walls 186 b , 188 b at their current spacing; and removing the gauge vane and substituting therefor vane 138 , which will have approximately 0.0020 inch clearance between one of its planar sides 156 , 158 and its adjacent vane slot sidewall. Referring now to FIGS. 50-55, model cylinder blocks are disclosed, functionally appertaining to all the cylinder blocks disclosed herein, however, simplified to aid in the explanation of the relationship between the vane slot and the cylinder block of the present invention compressor assembly. Referring now to FIG. 50, shown is a model cylinder block 76 a having a cylindrical cavity 80 a defined by a cylinder wall 81 a . Also shown is tapered vane slot 184 a cut all the way through the cylinder wall 81 a and extending to an outer periphery 78 a of the model cylinder block 76 a . The taper in tapered slot 184 a has been exaggerated for clarity. Vane slot 184 a is defined by a pair of vane slot sidewalls 186 a and 188 a , respectively, and further includes a first vane slot opening 189 a , proximate to the outer periphery 78 a of the model cylinder block 76 a , and a second vane slot opening 191 a , which is proximate to the cylinder wall 81 a within the cylindrical cavity 80 a . FIG. 50 shows tapered vane slot 184 a having the first vane slot opening 189 a , which is relatively narrower than the second vane slot opening 191 a , for reasons further described below. FIG. 51 discloses the insertion of a gauge vane showing the model cylinder block 76 a of FIG. 50, having a pair of equal and opposing forces 193 imparted on extended portions 185 a of the cylinder block to elastically spread apart the vane slot sidewalls 186 a and 188 a , respectively. A gauge vane 138 g has been inserted between the vane slot sidewalls 186 a , 188 a and is shown holding the vane slot sidewalls 186 a , 188 a apart, and substantially parallel. The gauge vane 138 g has first and second ends 139 and 140 , respectively, wherein the first end 139 of gauge vane 138 g has a tapered contour so that the gauge vane may be forcefully wedged into the first vane slot opening 189 , which acts similar to forces 193 spreading apart the vane slot sidewalls 186 a , 188 a , to fit the vane therebetween. With the gauge vane 138 g in place and having vane slot sidewalls 186 a and 188 a , respectively, in contact with the gauge vane 138 g , a state of stress develops in cylinder block portions 197 a and is represented by arrows 195 . The state of stress 195 is circumferentially oriented about the cylinder block 76 a and is disposed within cylinder block portions 197 a , which are located immediately adjacent cylinder wall 81 a , and continue circumferentially about the cylinder block 76 a . The state of stress 195 is tensile in nature and circumferentially orients therealong a substantial portion of cylinder block portions 197 a . State of stress 195 is caused by the spreading apart of vane slot sidewalls 186 a and 188 a , respectively, and once created, the cylinder block 76 a is secured by bolting or the like to an adjoining bearing or bearings, to preserve the stresses within cylinder block portions 197 a . Thus, once the gauge vane 138 g is removed the state of stress 195 remains preserved therein, as hereinafter described. Referring to FIG. 52, the model cylinder block 76 a is shown having preserved the circumferentially oriented stress, as shown by arrows 195 , however, the gauge vane 138 g has been removed and replaced by vane 138 . FIG. 52 shows, albeit exaggeratedly, a vane slot width “S” being preserved, with gauge vane 138 g removed, and the state of circumferentially oriented stress 195 remaining preserved therein. The vane 138 , having a width or thickness “T”, is freely reciprocatable within vane slot width “S”, the width between “S” and “T” defines a clearance. In order for vane 138 to reciprocate within vane slot width “S” the clearance must be suitable, however, an excessive clearance leads to premature vane wear, and additionally, inefficient compressor mechanism operation due to refrigerant gas blow-by through the clearance. Referring now to FIGS. 53-55, similar to FIGS. 50-52, a simplified cylinder block is shown, however the cylinder block has a closeable vane slot. Referring now to FIG. 53, shown is a model cylinder block 76 b having a cylindrical cavity 80 b defined by a cylinder wall 81 b . Tapered vane slot 184 b is cut all the way through the cylinder wall 81 b and extends to an outer periphery 78 b of the model cylinder block 76 b . The taper in tapered slot 184 b has been exaggerated for clarity. Vane slot 184 b is defined by a pair of vane slot sidewalls 186 b and 188 b , respectively and further includes a first vane slot opening 189 b , proximate to the outer periphery 78 b of the model cylinder block 76 b , and a second vane slot opening 191 b , which is proximate to the cylinder wall 81 b within the cylindrical cavity 80 b . FIG. 53 shows tapered vane slot 184 b , having the first vane slot opening 189 b , which is relatively broader than the second vane slot opening 191 b , for reasons further described below. FIG. 54 represents the gauge vane insertion or vane slot setting step of the inventive method, showing the model cylinder block 76 b of FIG. 53, having a pair of equal and opposing forces 199 imparted on extended portions 185 b of the cylinder block 76 b elastically closing together the vane slot sidewalls 186 b and 188 b , respectively. A gauge vane 138 g has been inserted between the vane slot sidewalls 186 b , 188 b and is shown contacting vane slot sidewalls 186 b , 188 b to provide a substantially parallel slot. Gauge vane 138 g used on cylinder block 76 a , may also be utilized on cylinder block 76 b in providing a standard in which to set the vane slot. With the gauge vane 138 g in place and having vane slot sidewalls 186 b and 188 b , respectively, in contact with the gauge vane 138 g , a circumferentially oriented state of stress 201 develops in cylinder block portions 197 b , which are located immediately adjacent cylinder wall 81 b . The cylinder block portions 197 b are circumferentially continuous about the cylinder wall 81 b . The circumferentially oriented state of stress 201 is compressive in nature, for a substantial portion of cylinder block portions 197 b about the cylinder wall 81 b . State of stress 201 is caused by the closing together of vane slot sidewalls 186 b and 188 b , respectively, and once the stress 201 is created, the cylinder block 76 is thereafter secured by bolting or the like to an adjoining bearing or bearings, to preserve the stresses within the cylinder block portions 197 b . Thus, subsequent to the gauge vane 138 g being removed the state of stress 201 is preserved therein, as hereinafter described. Referring to FIG. 55, the model cylinder block 76 b is shown having the gauge vane 138 removed and the gauge vane width “S” preserved. Also preserved is the circumferentially oriented compression stress 201 . FIG. 55 shows the vane 138 g in the vane slot 184 . The vane 138 b having a width or thickness “T” is freely reciprocatable within vane slot width “S” and the width between “S” and “T” defines a clearance. In order for vane 138 to reciprocate within vane slot width “S” the clearance must be suitable, however, an excessive clearance leads to excessive vane wear and malfunction. Also an excessive clearance coincides with inefficient compressor operation due to refrigerant gas blow-by through the clearance. As mentioned above, during the step of increasing the width “S” of the vane slot 184 a , cylinder block portions 197 a develop a state of circumferentially oriented tensile stress 195 , which is preserved once the cylinder block 76 a is clamped between outboard bearings 88 , 100 and main bearings 20 , 22 . In contrast, during the step of decreasing the width “S” of the vane slot 184 b , cylinder block portions 197 b develop a state of circumferentially oriented compressive stress 201 , which is preserved once the cylinder block is clamped between outboard bearings 88 , 100 and main bearings 20 , 22 . Generally, pre-stressing portions of the cylinder block 76 , as hereinabove explained, results in offsetting dynamic forces imparted on the cylinder block 76 by the rotating roller piston 132 , to enhance wear resistence and longevity of the cylinder block 76 . Furthermore, the tapered vane slotted cylinder block requires fewer machining operations and costly machining operations may be avoided. Referring now to FIGS. 1, 2 and 4 , and more specifically the liquid lubrication of the vane and vane slot, each liquid lubricant pool having surface level 118 in discharge chambers 32 , 36 is of sufficient height to immerse vane 138 in the pool of lubricant. Immersion of vane 138 in the lubricant seals the clearance between vane 138 , the sidewalls of vane slot 184 and the adjacent axial bearing surfaces against refrigerant blow-by from the compression chamber, as well as lubricates the vane surfaces. Referring again to FIG. 4, it can be seen that cylindrical discharge opening 190 is provided in the cylindrical wall of cavity 80 adjacent vane slot 184 , on the opposite side thereof from inlet opening 182 . By providing cylindrical discharge opening 190 in the wall of cavity 80 adjacent vane slot 184 , rather than in the axial surface of the outboard bearing, an outlet port of unchanging area is provided for discharge gases to be exhausted from the compression chamber throughout the compression cycle, regardless of the roller piston position. Adjacent and downstream of cylindrical discharge opening 190 is frustoconical valve seat 192 on which the mating frustoconical surface of head 194 of poppet 196 seals. Poppet head 194 is urged into sealing contact with surface 192 by compression spring 198 disposed about poppet shaft 200 . One end of spring 198 abuts the underside of poppet head 194 ; its opposite end abuts disc 202 , which is cushioned by neoprene cushion 204 and disposed in pocket 206 of poppet retainer 208 . Retainer 208 limits the radial travel of poppet 196 away from seat 192 to about ⅛ inch, the terminal end of poppet shaft 200 opposite head 194 abutting disc 202 at the furthest extent of poppet travel. Neoprene cushion 204 softens the impact of the poppet shaft end against disc 202 , thereby quieting the operation of the compressor. Poppet 196 prevents previously exhausted discharge pressure gases from reentering the compression chamber, where they would otherwise be recompressed, undermining the efficiency of the compressor. Poppet 196 is preferably made of a durable yet lightweight material, for example a plastic such as Vespel™, as may retainer 208 . Disc 202 may be plastic or metal. Retainer 208 is provided in radially extending cylinder block bore 210 and maintained in position therein by means of pin 212 extending through a pair of holes 214 provided on opposite axial sides of bore 210 . Pin 212 is prevented from moving axially within holes 214 by its ends abutting the adjacent axial surfaces of the main and outboard bearings. Discharge gases compressed in the compression chamber urge poppet 196 off its seat 192 against the force of spring 198 and flow past poppet head 194 into discharge cavity 216 provided in cylinder block 76 . Poppet 196 is urged by spring 198 back into sealing engagement with seat 192 once the discharge pressure gas has exited the compression chamber through opening 190 , preventing the expelled gas from flowing back into the compression chamber. Discharge cavity 216 extends axially between cylinder block surfaces 82 , 84 , and is defined by cavity surface 217 and the adjacent axial surfaces of the main and outboard bearings. Cavity 216 serves to attenuate gas-borne noises and pressure pulses arising from operation of the compressor. As shown in FIG. 4, discharge gases exit cavity 216 by means of discharge port 218 provided in outboard bearing 100 (and through corresponding port 220 in front outboard bearing 88 , FIG. 12 ). Discharge gases expelled from cylinder block discharge cavity 216 through discharge ports 218 , 220 enter respective discharge chambers 32 and 36 . Those of ordinary skill in the art will appreciate that discharge chambers 32 and 36 serve as mufflers as well, attenuating gas-borne noises and pressure pulses before discharge pressure refrigerant exits compressor assembly 10 through discharge conduit or tube 120 . Furthermore, each compressor mechanism 24 , 26 , respectively, draws refrigerant gases from the suction chamber 44 and discharges the compressed gases into the discharge chambers 32 , 36 respectively, to further attenuate sources of fluid borne noise and vibration which would be otherwise carried by suction conduits, discharge conduits and the like, rigidly connecting the housing to the compressor mechanisms. As shown in FIGS. 13 and 15, outboard bearings 88 and 100 are provided with conduits 222 and 224 which respectively extend from inlets 226 , 228 to outlets 230 , 232 . Inlets 226 and 228 are provided proximate the terminal ends of shaft 52 in respective bearing hub portions 234 , 236 ; outlets 230 , 232 open onto respective axial surfaces 86 , 98 into regions of the compression chambers which are at a pressure intermediate suction and discharge pressure (FIG. 4 ). The outboard axial surfaces of roller pistons 132 cover and block outlets 230 , 232 as the roller pistons reach orientations about the cylindrical surfaces of cavities 80 normally corresponding to pressures at and above which oil, which is approximately at discharge pressure, may be forced to reversibly flow backwards through conduits 222 , 224 . Referring to FIG. 1, it can be seen that front outboard bearing hub portion 234 is provided with oil diverter cap 238 , which may be made of sheet metal. Cap 238 directs oil received from shaft bore 110 and directs it towards inlet 226 of conduit 222 . Through conduit 222 oil is provided to the compression chamber of the front compressor mechanism, lubricating exposed surfaces therein. Similarly, hub 236 of rear outboard bearing 100 is provided with cap 240 enclosing a portion of pump 112 and which may also be made of sheet metal. Cap 240 is provided with an central aperture through which lubricant draw conduit or tube 114 is fitted. Cap 240 directs lubricant received from lubricant tube 114 upstream of pump 112 through inlet 228 of conduit 224 . FIGS. 16A through 16C detail the shaft 52 . As seen in FIG. 16B and 16C, at the point of respective small diameter shaft portions 60 and 58 about which eccentrics 122 are attached thereto. FIG. 16B shows that shaft portion 60 is provided with crossbore 242 which extends through the diameter of shaft portion 60 intersecting axial bore 110 . FIG. 16C shows that shaft portion 58 is provided with similar crossbore 244 . Referring now to FIGS. 17A and 17B, there is shown cross-sectional views of eccentric 122 , which as discussed above is attached to the shaft 52 at countersinks 130 provided in shaft portions 58 and 60 . Eccentric 122 is provided with axial bore 246 having centerline 248 offset and parallel to axis 250 of shaft 52 (FIG. 16 A). Eccentric 122 is provided with crossbore 252 which extends through eccentric bore 246 to a second axial bore 254 extending between the axial surfaces of the eccentric. With eccentric 122 assembled to shaft portions 58 , 60 , eccentric crossbore 252 is brought into alignment with shaft crossbores 244 and 242 . Because one end of crossbore 252 opens to outside surface 134 of the eccentric, oil provided through bore 110 to aligned bores 242 , 252 and 244 , 252 lubricates the interfacing cylindrical surfaces 133 and 134 between roller piston 132 and eccentric 122 . The opposite end of crossbore 252 extends into axial eccentric bore 254 , providing oil received from shaft bore 110 axially into the forward and rear spaces provided between the eccentric axial surfaces and the adjacent axial surfaces of the main and outboard bearings, these spaces inside surface 133 of roller piston 132 ; during normal compressor operation, these spaces are filled with oil. Referring now to FIG. 18, there is shown compressor assembly 10 ′, a second embodiment according to the present invention. Compressor 10 ′ is for the most part identical with compressor assembly 10 , except is adapted to be vertically oriented. Thus with respect to the preceding discussion, the forward compressor mechanism 24 is, in this second embodiment, referred to as upper compressor mechanism 24 ′. Similarly, with respect to the preceding discussion, rear compressor mechanism 26 is now lower compressor mechanism 26 ′. All previously discussed components of compressor assembly 10 are configured and carried over into compressor assembly 10 ′ in the same way except as distinguished hereinbelow. Compressor assembly 10 ′, being vertically oriented, has a pair of pools of liquid lubricant having levels 118 ′ in each of its discharge chambers 32 , 36 . The level of lubricant or oil 118 ′ in upper discharge chamber 32 is, in normal operation of compressor assembly 10 ′, above axial surface 86 of upper outboard bearing 88 ′. Thus vane 138 of upper compressor mechanism 24 ′ is, as described with respect to front and rear compressor mechanisms 24 , 26 of compressor assembly 10 , immersed in oil. Oil may initially collect in the lower portion of suction chamber 44 , as shown in FIG. 18 having level 166 ′, however, the oil eventually aspirates through the suction port 170 (FIGS. 7 and 8 ), and commonly exhibits a negligible level therein. As described above, oil will be scavenged from chamber 44 through aperture 174 in lower main bearing 22 . Aperture 172 of upper main bearing 20 will draw suction pressure gas into port 168 instead of oil. As best seen in FIG. 19, oil draw tube 114 ′ extends downwardly from cap 240 to provide access to the oil in the lower portion of chamber 36 . Compressor assembly 10 ′ employs the same lubrication methods as described above, with the exception that, because vane 138 of lower compressor mechanism 26 ′ cannot be immersed in oil, additional lubrication providing means is provided. Referring to FIG. 21, there is shown cylinder block 76 ′ which is identical to cylinder block 76 with the exception that sidewalls 186 , 188 of vane slot 184 are provided with scallops 256 , 258 , respectively. These scallops have the shape of a circle segment and, as will be described further below, allow oil to be provided adjacent the planar sides of vane 138 in lower compressor mechanism 26 . Referring to FIG. 22, it is seen that lower outboard bearing 100 ′ is provided with an axially directed through bore 260 of size matching the circle which would be defined by scallops 256 and 258 in cylinder block 76 ′. Into bore 260 is press fitted second oil draw conduit or tube 262 which extends from the location approximate surface 98 of outboard bearing 100 ′ downwardly into the oil contained in the lower portion of chamber 36 . During operation of compressor assembly 10 ′, as vane 138 reciprocates in compressor mechanism 26 ′, the oil in chamber 36 , which is under discharge pressure, is drawn through oil draw tube 262 into scallops 256 , 258 , sealing the gap between vane slot sidewalls 186 , 188 and planar sides 156 , 158 of the vane. Thus, it can be seen that oil forced or drawn upward through tube 262 lubricates and seals vane 138 in vane slot 184 . Upper compressor mechanism 24 ′ may utilize a common cylinder block 76 ′. Upper outboard bearing 88 ′, may be provided with bore 264 corresponding to bore 262 in lower outboard bearing 100 ′ to, perhaps, better facilitate machining operations. If upper outboard bearing 88 ′ is provided in compressor assembly 10 ′ instead of outboard bearing 88 , bore 264 would be plugged to prevent the ingress of discharge pressure gasses from chamber 32 into scallops 256 , 258 . Bore 264 would be plugged with plug 266 (FIG. 18 ). Referring to FIG. 24, a third embodiment of the twin rotary compressor assembly 10 ″ is shown and is similar to the first embodiment compressor assembly 10 except as identified hereinbelow. Refrigerant gases, at suction pressure, flow into tube 164 ″ through filter 165 ″ and into suction chamber 44 . Chamber 44 , as in the first embodiment, is the suction chamber wherein the motor assembly 46 is immersed in relatively cool refrigerant gases. Following introduction into suction chamber 44 , refrigerant then flows through identical suction mufflers 268 , fastened to front and rear main bearings 20 ″, 22 ″ respectively, as shown. Suction mufflers 268 are thin metallic or plastic discs, overlaying axial surface 40 ″ of the front bearing 20 ″ and surface 42 ″ of the rear bearing 22 .″ Suction mufflers 268 have collar portions 270 , which are slightly larger in diameter than hubs 68 ″ and 74 ″ to allow refrigerant gases to pass therebetween. Each suction muffler 268 , acts to slow down the refrigerant gases entering each compressor mechanism to alleviate and attenuate noise otherwise manifested by free flowing refrigerant gases. Similar to the operations of the first embodiment compressor assembly 10 , as previously described above, compressor assembly 10 ″ compresses refrigerant in compressor assemblies 24 ″ and 26 ″ and discharges the compressed gases into front discharge chamber 32 and rear discharge chamber 36 through front and rear outboard bearings 88 ″ and 100 ″, respectively. The discharge gases carrying fluid-borne noise are muffled by first housing portion 14 ″ and second housing portion 18 ″. Discharge gases within chamber 32 , as well as discharge gases from chamber 36 , communicate via external cross-over tube 115 ″. The merged discharge gases are then dispersed through the discharge tube 120 ″ exiting the housing 12 ″ of the compressor assembly 10 ″. The compressor assembly 10 ″ supports shaft 52 ″ at two locations, namely, a front portion 282 and a rear portion 280 . At the front portion 282 of the shaft 52 ″, the supporting structure includes the front main bearing 20 ″ wherein the front main bearing 20 ″ includes a bushing 272 which contacts the large diameter portion 56 ″ of the front portion 282 of the shaft 52 ″. Likewise, at the rear portion 280 of the shaft 52 ″, the rear main bearing 22 ″ supports the shaft 52 ″ through rear bushing 274 . The shaft 52 ″ freely rotates within the front and rear bearings, however, endwise movement of the shaft 52 ″ is restrained by common cover plate 288 . Cover plates 288 mount to the front outboard bearing 88 ″ and the rear outboard bearing 100 ″, each secured by a pair of screws 292 , to restrain endwise movement of the shaft 52 ″. Referring now to FIG. 25, orientation of shaft 52 ″, eccentric 122 ″ and roller piston 132 , and additionally, lubrication thereof, will now be discussed. The crossbore 252 ″ in eccentric 122 ″ aligns with the crossbore 244 ″ in the front portion 282 of the shaft 52 ″ to allow oil to flow to the roller piston 132 . Oil travels through bore 286 , down the centerline of the shaft 52 ″, entering crossbore 244 ″ and crossbore 252 ″ of eccentric 122 ″ to coat the inner surface 133 of the roller piston 132 . Eccentric 122 ″ includes a pair of reliefs 294 along the outer surface 134 ″ of the eccentric 122 ″ in order to increase oil flow to the inner surface 133 of the roller piston 132 as well as a pair of axial faces 295 of the eccentric 122 ″. Also shown is outboard bearing 88 ″ having an oil passageway 298 , well below oil level 118 so that vane 138 ″ reciprocating between vane slot surfaces 296 are well saturated in oil to prevent refrigerant gas blow-by. Referring to FIG. 26, the outboard bearing 88 ″ includes a raised portion 234 ″, the discharge port 220 ″, and the oil passageway 298 . The raised portion 234 ″ of the outboard bearing 88 ″ also includes threaded holes 300 to fasten cover plates 288 thereto. Oil passage 298 in outboard bearing 88 ″ is shown well below oil level 118 allowing oil to enter passageway 298 and generally saturate vane 138 ″ and vane slot 184 ″ in oil. Discharge port 220 ″ is shown well above oil level 118 so that under normal operation of the front compressor mechanism 24 ″ oil does not create a back pressure and refrigerant gases may freely exit discharge port 220 ″. Referring to FIG. 27, within the front compressor mechanism 24 ″ is shown the roller piston 132 , the eccentric 122 ″ and the shaft 52 ″ wherein the eccentric 122 ″ is pinned to the shaft 52 ″. The rear compressor mechanism 26 ″ involves an identical configuration in that the eccentric 122 ″ is thereby pinned to the shaft 52 ″. Momentarily referring to FIG. 42, there is seen a groove 306 in the shaft 52 ″ receiving a pin 302 (FIG. 27) and further, as shown in FIGS. 43-45 there is a groove 34 in the eccentric 122 ″ that receives the pin 302 , thereby securing the eccentric 122 ″ to the shaft 52 ″. Referring again to FIG. 27, and more specifically the area about vane 138 ″, vane 138 ″ is shown in vane slot 184 ″ and held in contact with the roller piston 132 by biasing member or spring 142 ″. Spring 142 ″ is restrained within a spring cavity 308 by a cover 310 and cover 310 is secured by screw 312 . Screw 312 is threaded into hole 314 which is within cylinder block 76 ″. Scallops 256 ″ and 258 ″ can be seen disrupting spring cavity 308 as scallops 256 ″ and 258 ″ are continuous along the width of cylinder block 76 ″. Cylinder block 76 ″ includes an inner wall 313 defining a portion of the discharge cavity 216 ″ wherein a reed valve 318 and retainer 320 are secured. Reed valve 318 and retainer 320 operate by allowing compressed discharge gases to escape the cylindrical cavity 80 , and in addition, to keep discharge gas from flowing back into the cylindrical cavity 80 . The reed valve 318 and the retainer 320 are secured to the cylinder block 76 ″ by way of a pair of threaded fasteners 322 . Referring to FIG. 28, the retainer 320 and the corresponding reed valve 318 include three individual fingers which correspond with three discharge openings 316 (FIG. 35 ). The retainer 320 has a first end 323 which is secured by fasteners 322 and a second end 325 including the three fingers extending therefrom. The three fingers of the retainer 320 overlay the three discharge openings 316 . Corresponding reed valve is sandwiched between the retainer 320 and inner wall 323 . Each finger of the retainer is held away from the inner wall 313 and acts as a stop for each corresponding finger of the reed valve 318 . Pressure within the cylindrical cavity 80 increases until the fingers of the reed valve are displaced and cylinder pressure is alleviated. The fingers of the reed valve 318 return to their original position overlaying the inner wall 313 when cylinder chamber pressure is sufficiently decreased. The retainer 320 may be made of a metallic material or a suitable rigid, high temperature plastic. The reed valve 318 may be made of a metallic material or a suitable high temperature polymer. Also shown in FIG. 28 are a pair of bolt holes 324 which receive bolts 336 to fasten cylinder block 76 ″ to the front main bearing 20 ″ and the rear main bearing 22 ″. Referring now to FIG. 29, outboard bearing 20 ″ includes control surface 28 ″ which serves as a partition to separate discharge chamber 32 from suction chamber 44 . Main bearing 20 ″ includes the pair of holes 326 that receive the bolts 336 (not shown) to fasten the cylinder block 76 ″ to control surface 28 ″ of the main bearing 20 ″. The main bearing 20 ″ also includes three threaded holes 331 which receive three threaded fasteners or bolts 90 (not shown) to secure not only the cylinder block 76 ″ but the outboard bearing as well. Suction port 168 ″ is a continuous hole through bearing 20 ″ and aligns with the suction portion of cylinder block 76 ″. Referring now to FIG. 30, the side opposing control surface 28 ″ of main bearing 20 ″ is shown including a well portion 328 and several raised portions thereon. Three distinct and equally radially displaced raised portions 330 include threaded holes 331 which receive bolts 90 (not shown) to clamp the cylinder block 76 ″ between the front main bearing 20 ″ and the front outboard bearing 88 ″ (not shown). A pair of raised portions 332 include a first set of threaded holes 324 to receive bolts 326 in mounting the cylinder block 76 ″ to the front main bearing 20 ″. A second set of threaded holes 335 are included in raised portions 332 and receive screws 334 (not shown) to hold the suction muffler 268 thereagainst. The final raised portion 338 also includes threaded hole 335 to secure the suction muffler 268 in a third location to the front main bearing 20 ″. The front main bearing 20 ″ also includes suction port 168 ″ aligning with the suction port 180 ″ of the cylinder block 76 ″ and bushing 272 , within the center portion of front main bearing 20 ″ and supporting shaft 52 ″. Referring to FIG. 31 and front main bearing 20 ″ in FIG. 29, rear main bearing 22 ″ is a mirror image of 20 ″. Rear main bearing 22 ″ includes a control surface 29 ″ which encloses discharge chamber 36 and separates discharge chamber 36 from suction chamber 44 . Rear main bearing 22 ″ includes a pair of threaded holes 326 to secure cylinder block 76 ″, and in addition, three threaded holes 331 which fasten the rear outboard bearing 100 ″ to the rear main bearing 22 ″ sandwiching the cylinder block 76 ″ therebetween. The rear main bearing 22 ″ also includes a hole therethrough 170 ″ aligned within suction port 180 ″ of cylinder block 76 ″ to allow suction gases within chamber 44 to enter cylinder block 76 ″ in the rear compressor mechanism 26 ″. Referring now to FIG. 32, the rear main bearing 22 ″ is a mirror image of front main bearing 20 ″, as shown in FIG. 30, and its ‘structure’ and operation is similar thereto. Referring now to FIG. 33, rear main bearing 22 ″ includes through holes 331 to receive bolts 90 (not shown) fastening rear outboard bearing 100 ″ to rear main bearing 22 ″. A second hole 335 is shown, which does not continue through the width of the rear main bearing 22 ″. A portion of hole 335 is threaded to receive a fastener 334 to secure the suction muffler 268 to the axial surface 42 ″ of rear main bearing 22 ″. Referring now to FIG. 34, a common cylinder block 76 ″ of the third embodiment is shown. The vane slot 184 ″ includes an upper portion 340 and a lower portion 342 . The upper portion 340 of the vane slot 184 ″ includes the surfaces 186 ″ and 188 ″ contacting the vane 138 ″, whereas during compressor assembly 10 ″ operation, the lower portion 342 of the vane slot 184 ″ does not contact vane 138 ″. The upper portion 340 of the vane slot 184 ″ is separated from the lower portion 342 by scallops 256 ″ and 258 ″, respectively. Cylinder block 76 ″ includes holes 94 which facilitate outboard bearing bolts 90 (not shown) and additionally, holes 324 to facilitate cylinder block screws 334 (not shown). Referring to FIG. 35, cylinder block 76 ″ includes the inner wall 313 partially defining the discharge cavity 216 ″ which accommodates the retainer 320 and reed valve 318 . More specifically, a pair of holes 344 include threads which receive a pair of screws 322 (FIG. 28) to secure the retainer 320 and reed valve 318 . Also, within inner wall 313 are three discharge openings 316 which fluidly connect discharge cavity 216 ″ to cylindrical cavity 80 . Discharge openings 316 in inner wall 313 are overlayed by the three fingers of the reed valve 318 (FIG. 28 ). Cylinder block 76 ″ also includes a spring cavity having a suitable depth to receive an adequate sized spring, such as spring 142 ″ (FIG. 27 ), however leaving enough cylinder block material to form an adequately supportive vane slot for the vane 138 ″. Referring to FIGS. 36-38, there is shown the front outboard bearing 88 ″ and more specifically the oil conduit 224 ″ contained therein. FIG. 37 displays oil conduit 224 ″ having a conduit inlet 226 ″ at chamfer 346 extending diagonally through the width of the outboard bearing 88 ″, and exiting at conduit outlet 230 ″ of the axial surface 86 ″. Conduit outlet 230 ″ is positioned within an interior portion of the cylindrical cavity 80 to expose front portion 282 of shaft 52 ″ to a lower pressure than rear portion 280 of shaft 52 ″. This pressure difference acts to draw oil from rear portion 280 of shaft 52 ″ to front portion of shaft 52 ″ through bores 284 and 286 , respectively (FIG. 24 ). This “rear to front” migration of oil through shaft 52 ″ ensures oil is introduced into cylindrical cavities 80 for proper lubrication of the roller piston 132 ″ and surfaces defining the cylindrical cavity 80 . FIG. 38 displays the pair of holes 300 which threadably receive screws 292 to secure cover plate 282 in restraining endwise movement of shaft 52 ″. Referring to FIG. 39, rear outboard bearing 100 ″ is shown with the oil pump assembly 112 ″. Rear outboard bearing 100 ″ includes two through holes: the oil passageway 298 and discharge port 218 ″. Referring now to FIGS. 40-42, shaft 52 ″ includes the front portion 282 and the rear portion 280 coinciding with the front and rear ends of the compressor assembly 10 ″. A center portion of the shaft includes a surface 56 ″ which is in rotational contact with the front bushing 276 and the rear bushing 278 . On shaft 52 ″ are a pair of O-ring grooves 276 and 278 , respectively, which receive O-rings (not shown). O-ring grooves 276 and 278 , respectively, serve to separate the suction chamber pressure within suction chamber 44 from the discharge chamber pressure in front chamber 32 and rear discharge chamber pressure in rear chamber 36 . Shaft 52 ″ includes a large diameter inner bore 286 and a somewhat smaller bore 284 extending through the rear portion 280 of the shaft 52 ″. Cross bore 242 ″ allows oil, being drawn from the rear portion 280 of the shaft, into eccentric 122 ″, similarly, cross bore 244 ″ allows oil being drawn from the rear portion 280 of the shaft 52 ″ and into eccentric 122 ″ positioned at the front portion 282 of the shaft 52 ″. Referring to FIG. 41, crossbore 242 ″ is shown intersecting through bore 284 to facilitate the migration of oil into eccentric 122 ″. Also shown is surface 60 ″ including a disruption thereon in the form of a pin groove 350 . Referring to FIG. 42, the front portion 282 of the shaft 52 ″ includes outer surface 56 ″, front small diameter portion 58 ″ and pin groove 306 thereon. Crossbore 244 ″ intersects inner bore 286 to welcome oil migration into the eccentric 122 ″ attached thereto (not shown). Referring now to FIGS. 43-45, eccentric 122 ″ includes a pair of reliefs 294 and inner bore 246 ″ formed continuously through and a pin groove 304 therealong. During operation of the compressor 10 ″, oil moves through passageway 252 ″ towards the outer surface 134 ″ of eccentric 122 ″ coating the outer surface 134 ″ as well as the inner surface 133 of the roller piston 132 . The pair of reliefs 294 facilitate optimum lubrication of axial faces 295 of the eccentric 122 ″. Referring now to FIG. 46, a fourth embodiment of the compressor assembly 10 ′″ of the present invention is shown and is similar in many aspects to the third embodiment 10 ″, however, vertically oriented. The compressor assembly 10 ′″ includes a lower compressor mechanism 26 ′″ having an oil suction tube 262 ″ sealably fitting into an oil passageway 353 in lower outboard bearing 100 ″ to draw from oil level 118 ″ and lubricate the vane 138 ′″. Also included in this particular embodiment is an elbowed pump intake conduit in the form of a tube 354 within the oil pump assembly 112 ′″ to draw oil vertically and into the lower portion 280 of the shaft 52 ′″. The oil level in the upper discharge chamber, nearing the discharge port, becomes an undesirous source of backpressure if such level exceeds the discharge port, however, nonetheless depicted to set forth that the reed valve 318 (FIG. 28 ), within the cylinder block, may suffice as an oil barrier to block excessive amounts of oil attempting to enter the cylindrical cavity via the discharge port. Referring to FIG. 47, yet another embodiment, the fifth embodiment of the present invention compressor assembly 10 ″″, discloses a cascaded compressor assembly, or series configuration, such that general operation can be described as follows: a first compressor mechanism 24 ″″ compresses refrigerant gas to an intermediate pressure stage and discharges such pressurized gas to a second compressor 26 ″″, via an suction tube 356 , wherein the final discharge pressure is obtained. More specifically, refrigerant gas is introduced at a suction pressure within suction chamber 44 and thereafter is suctioned into front compressor 24 ″″, exclusively. The gas at suction pressure is then compressed to an intermediate pressure and dispersed within discharge chamber 32 . Thereafter, the refrigerant gas at intermediate suction pressure and within discharge chamber 32 is extended through suction tube 356 . Suction tube 356 is in exclusive communication with an suction port 358 located on an axial surface 359 of the outboard bearing 100 ″″ of the rear compressor mechanism 26 ″″. The intermediate stage refrigerant gas, supplied to compressor 26 ″″ by suction tube 356 , is further compressed and discharged into discharge chamber 36 . The discharged refrigerant, at the secondary or maximum pressure, within chamber 36 exits the compressor housing 12 ″″ through discharge tube 120 ″″. Referring to FIG. 48, the rear outboard bearing 100 ″″ has an suction port 358 , sealably receiving the suction tube 356 , the oil passageway 298 ″″ and the discharge port 218 ″″. Once again, oil level 118 ″″ substantially covers the vane 138 ″″ and vane slot 134 ″″ (see also FIG. 47 ). However, it can be seen care is taken to avoid oil level to reach discharge port 218 ″″. Suction port 358 seals around suction tube 356 therefore an oil level 118 ″″ substantially thereover the suction port 358 will not hinder operation of the compressor assembly 10 ″″ whatsoever. Referring to FIG. 49, main bearing 22 ″″ has control surface 29 ″″ with cylinder block 76 ″″ attached thereto. However, in contrast to the previously hereinabove described compressor assembly embodiments, compressor assembly 10 ″″ includes the main bearing 22 ″″ which does not fluidly communicate with the suction chamber 44 . While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of this disclosure. Therefore, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. For example, aspects of the present invention may be applied to single cylinder rotary compressors. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

A hermetic rotary compressor assembly having a housing, a cylinder block and a bearing assembly within the housing. The cylinder block and the bearing assembly define a cylindrical cavity which has a roller piston disposed therein. The rotary compressor assembly includes a motor drivingly coupled to the roller piston and the cylinder block has a vane slot extending completely axially through and extending radially from an outside perimeter surface of the cylinder block to the cylindrical cavity. At least a portion of the vane slot is defined by a pair of substantially parallel sidewalls and a vane is disposed in and guided by the vane slot and is urged against said roller piston. The cylinder block is fixed in a state of circumferentially oriented stress. A method to assemble the rotary compressor includes spreading apart the sidewalls of the vane slot in the cylinder block, inserting into the spread apart slot a gauge vane of thickness greater than the thickness of a reciprocating vane, releasing the block to cause the slot sidewalls to engage the gauge vane, fixing the cylinder block to hold the engaged sidewalls, removing the gauge vane from the slot, and inserting the reciprocating vane in the slot, whereby a clearance is maintained between the reciprocating vane and slot sidewalls. Another method includes closing together sidewalls of the vane slot to engage the gauge vane, fixing the cylinder block to hold the engaged sidewalls, removing the gauge vane from the slot, and inserting the reciprocating vane in the slot.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a filter device for separating gaseous organic impurities from waste gases. 2. Background of the Prior Art As used herein, the term gaseous organic impurities means all waste gases which originate from organic degradation processes, for example, from animal farms, from processing operations in animal carcass utilization plants, from fermentation and rotting or digestion processes, as well as from industrial plants. It is well known that gaseous impurities may be separated from waste gases by using filters which consist of a drum-shaped, rotating separating unit which rotates about an axis and contains filter material, e.g., low-temperature coke from peat, brown coal, bituminous coal or wood charcoal, such as those described in the German Offenlegungsschrift 1,619,861. Of course, whenever the adsorption capacity is exhausted, a new charge has to be introduced into the separating unit. By these processes, gaseous impurities, especially in the form of sulfur dioxide, can be removed by adsorption from waste gases since sulfuric acid is formed in the presence of oxygen and water vapor, and the sulfuric acid must be released in a processing step that follows the absorption. Experience has shown that the organic impurities mentioned hereinabove can only be incompletely separated and converted with such devices. The impurities and extraneous materials that occur, cannot all be adsorbed and the porous surface of such absorbents, and of filters that may be positioned before the absorbents are quickly blocked by suspended matter in the waste gases. BRIEF DESCRIPTION OF THE DRAWING The drawing is a cross-sectional view of an apparatus in accordance with the present invention. SUMMARY OF THE INVENTION It has been discovered that the filtration of organic compounds from waste gases can be significantly improved, if they are passed through an absorbent that moves, in the manner of a migrating layer, from top to bottom through a vessel, through which the waste gases flow. The absorbent for the process is an incompletely decomposed compost of organic waste, obtained by an aerobic digestion process and/or settled sludge. The spent filter material is continuously removed from the vessel and continuously replaced by fresh filter material. Such a filter device therefore requires a digestion reactor and organic waste in sufficient amounts. However, these requirements cannot be fulfilled everywhere. The object of the present invention is to create, using the exchange of filters, a filter device that is easy to operate, that produces, without a digestion reactor, a significantly improved filtration result in comparison with known filters and that is constructed in such a way, that the filter material can be exchanged readily. The objects of the invention have been accomplished by a vessel which has a coupling flange, is connected to a stationary rack by means of quick-release couplings and which contains as an absorbent, a biologically highly active compost of a medium degree of maturity. This absorbent is obtained by an aerobic digestion process from organic waste and/or settled sludge and that contains about 30% to 35% water and about 55% to 70% organic material and is treated with microorganisms of the species. Actinomyces globisborus, flavus and farinus, and fungi of the Coprinus variety, the Aspergillus and Mucor species. DESCRIPTION OF THE PREFERRED EMBODIMENT According to a preferred embodiment of the invention, the vessel is in the form of a portable container and has an inlet in its base and an outlet in its lid. The inlet is connected to an inlet connecting piece attached to a supporting frame for the container. The inlet connecting piece fits into registration with the inlet of the container to form a gas-tight connection. This is further connected to a jet system within the vessel at its base and has an indicator for showing the biological effectiveness of the absorbent. In the filter device of the invention, the actual filter accordingly is a container, which holds a biologically active humus as a filter material and which is connected, in such a way that it can readily be connected to and removed from a stationary device that has all the connections and and auxiliary units. As a result, the container having the fresh humus therein may be easily connected to the stationary device, utilized to process the gas, and when the activity of the humus has deteriorated to an insufficient level, the entire container can be easily disconnected and another container with fresh humus be substituted in its place. The filter material is highly populated with microorganisms. As the organic, gaseous impurities, which are to be purified, are passed into the vessel, the microorganisms in the filter material receive nourishment once again and therefore become active once more. In this biologically active filter material, a vigorous reaction takes place, that is to say, further decomposition as well as biological degradation reactions proceed. Sulfur dioxide compounds are filtered out by the filter, as generally is the case with the known filters. Also all of the remaining organic compounds, that occur in the waste gases, are converted or degraded and even heavy metal ions are immobilized, if suitable additives, such as, bentonite, are used. The exhaust air leaving the filter device is absolutely free of any odors and has been purified to remove all injurious materials. This is due to the use of a filter material which is highly active biologically. Thus, in contrast to the known filter materials, continuous reactions take place in this material which contribute biologically to the rotting or digestion of the material and in which the odoriferous and injurious materials of the waste air or gas are included and thereby converted or degraded. It has therefore turned out that this filter material can also be used to advantage in those situations where a filter material, consisting of dried humus -- a so-called earth filter -- has hitherto been used. It ought to be mentioned that, while the filter of the invention is being used, the filter material contained therein digests further and, after biological reactions can no longer be detected and the filter therefore has only limited usefulness, the filter material can also be used as a humus material, possibly after a post-composting. After the filter material is spent, as shown bby suitable indicators, for example, by conductivity measurement, by biological activity measurements, by measurement of a certain gas in the waste air, etc., the container is lifted from the rack and a second container, which is already filled with fresh filter material is put in its place. The container, that has been lifted off, is emptied at a suitable site and filled with fresh filter material. In order to maintain the effectiveness of the filter at a high level, it may be advantageous that a blower, that can also draw in fresh air be connected to a waste-air connecting piece on the rack in order to regulate the waste air flowing through the container and that this blower be connected by means of quick-release couplings with the corresponding connecting piece of the container. This measure depends essentially on the amount and the rate of flow of the waste air. The correct rate of flow can be determined by simple experiments. The capacity of such a container is selected to be between two and ten cubic meters, in order to hold the amount of filter material necessary for maintaining biological activity, while keeping the size of the container such that it can still be transported. Containers of this size can easily be brought to the site of the filter and lifted, by means of a crane mounted on a truck, onto or off the rack and transported from there to the place where they are to be filled. Referring now to the drawing, a device for filtering waste gases is shown consisting of a stationary rack 1, on which is placed a vessel 2 in the form of a container or chamber, which is adapted to be lifted from the rack 1. The vessel 2 consists of a middle piece 3 in the form of a cylindrical jacket, which is connected with upper and lower lids 4 and 5, respectively, by means of tightening screws 6 and locks 7 so as to be gas-tight and detachable. The upper lid 4 has an outlet 8 and the lower lid 5 an an inlet 8, as well as a system of jets 10 as means for distributing the gas. Also attached to lower lid 5 are supporting legs 11. By means of rings 12, the vessel can be lifted from the rack 1. The rack has a seating means 13 for centering the vessel thereon. An inlet connecting piece is arranged centrally in this seating and is connected with a quick-release coupling, which is not shown, to pipe 15, which leads to the waste air which is to be purified. When placed on the rack, inlet 9 of the vessel matches or is in registration with the inlet connecting piece 14 of the rack 1, so as to be form-fitting and gas-tight. The inlet 9 is in turn connected with the system of jets 10, which has already been mentioned and which is arranged in the base of the vessel. As indicated, a suction blower 17 can, if necessary, be connected via a waste-gas connecting piece 16 with the outlet 8. The vessel 2 is filled with aggregate 18, which is used as filter material and which consists of a biologically highly active compost of a medium degree of maturity, which may be obtained by a process according to German Auslegeschrift 2,253,009. The degree of maturity and thereby the biological activity of the filter material is measured by a suitable probe. Typically, the means for measuring the biological activity may include a conductivity measurement, a biological activity measurement, measurement of a certain gas in the waste air, etc. The activity is shown on an indicating instrument 20. This instrument determines and can be adapted to continually check whether the filtering material still has the desired filtering properties. The probe may be mounted in the waste-air connecting piece 16 at 19a. The compost, used as filter material, contains about 30-35% water and about 55-70% organic material, as well as microorganisms of the Actinomuces globisborus, flavus and farinus species and fungi of the Coprinus variety, the Aspergillus and Mucor species. When the waste gas containing the organic impurities flows by way of the jet distribution system 10 through the filter material and is distributed over the area of the vessel, the organic compounds become involved in the biological reactions which cause the compost to rot, and thus they are completely converted or degraded. Even heavy-metal ions in the waste air are immobilized in the filter material, if bentonite is introduced as additive into the aggregate. As soon as the filter material no longer has the desired properties, the pipe connections are loosened and the vessel is lifted off the rack, transported away and emptied at a central site and filled up again. Since the rotting has continued while the filter was in use, the spent filter material is a hygienically unobjectional humus material. When the first vessel is taken off the rack, it is replaced by a second one, which is already filled with fresh filter material. This second vessel is then connected to the feed pipes. Using the device, described in the invention, for filtering organic impurities from waste gases, it is possible, by a simple and economic procedure, to filter and completely free such waste gases which may originate, for example, from animal farms, from fermentation or rotting processes, from industrial plants and from odoriferous materials.

A method for removing gaseous organic impurities from waste gases comprising contacting the waste gas with an absorbent composed of a biologically active compost having a medium degree of maturity obtained by the aerobic digestion of settled sludge or organic waste which has been treated with Actinomyces globisborus or Coprinus fungi. An apparatus for carrying out the process is also disclosed.

BACKGROUND The present invention generally relates to the area of luggage options for motorcycles. Specifically, this invention relates to luggage which may readily be fastened to a motorcycle, the luggage having internal shelves, thus providing ease, convenience, and organization for the rider and/or passenger in transporting their belongings by motorcycle. Limited space is available on motorcycles for a rider and the rider's passenger to carry their belongings. Some motorcycles may come equipped with large capacity saddlebags or panniers hanging down on either side of the rear wheel, as shown in U.S. Pat. No. 4,442,960 (Vetter). However, such luggage can be expensive, difficult to remove from the motorcycle, and too bulky to easily hand carry when the rider wishes to carry his or her belongings into a motel, campsite or other lodging. Moreover, some motorcycle riders feel such luggage is unsightly on their motorcycles and creates additional surface area for wind resistance. Because of the disadvantages of mounting motorcycle luggage on either side of the wheel, U.S. Pat. No. 5,405,068 (Lovett) proposes a bag supported by either the motorcycle seat member or by a rack structure. An object of the bag in the '068 patent is to overcome the disadvantages of the saddlebags or panniers by providing a travel bag which can be easily attached and removed from the motorcycle. This bag is secured to the motorcycle through the use of a pocket on the front of the bag, where the pocket is sized to fit snugly over the rear passenger seat back or sissy bar. The pocket is located on the bag so that the bottom of the bag will just rest on the luggage rack when the seat back is completely inserted into the pocket. However, careful construction of the pocket is central to the successful operation of this bag. The pocket must be so constructed that the internal volume of the pocket is less than this bag. The pocket must be so constructed that the internal volume of the pocket is less than the volume of the padded seat back, because the pocket must partially compress the resilient material of the seat back for the bag to be securely attached to the motorcycle. Because the rear seat back varies in dimensions from model to model of motorcycle, it is necessary to specifically size the pocket and the rest of the bag for each particular model of motorcycle. Another disadvantage of fabric bags, which have no internal reinforcement members, is that the bag must be completely filled, because a loosely filled bag will vibrate and flap when the motorcycle is in motion. The bag disclosed in the '0068 patent partially solves this problem through the use of a zippered gusset that allows the travel bag to expand as extra space is required. However, depending upon the volume of items to be stored in the bag, if the bag disclosed in the '0068 patent is only partially filled, with the zippered gusset closed, excess fabric may still vibrate and flap. A feature common to most previous motorcycle luggage, including saddlebags, panniers, and the bag disclosed by the '0068 patent, is that the main storage space defined by each of these devices is merely a large enclosure with minimal internal structure for organizing the user's belongings. The user fills the enclosure with his or her belongings from the bottom of the luggage device until the luggage is fully loaded. However, because there is no internal structure, items packed within the enclosure may shift during travel, with smaller or heavier items working to the bottom of the enclosure. Although the user, desiring to have ready access to certain items, may pack these items at the top of the enclosure, it may be necessary to completely empty the bag in order to locate the items because they may have shifted to the bottom of the enclosure during travel. The lack of internal storage structure in existing motorcycle luggage also results in clothing items becoming crumpled and wrinkled from shifting of the packed items. Clothing items which were neatly pressed when placed within the luggage become wrinkled because there is no internal structure for supporting and protecting clothing from being crumpled inside the luggage. SUMMARY OF THE INVENTION The present invention is a travel bag adaptable for motorcycle transportation. The invention is comprised of a shell, a shelving insert contained within the shell, and securing members for securing the travel bag to a motorcycle. The shell is opened by operating fasteners allowing access to the shelving insert and the inside of the shell. The shelving insert has a top shelf, bottom shelf, two side pieces and a plurality of intermediate shelves, and may have a back piece. The travel bag provides a convenient and secure apparatus for organizing, storing and transporting clothing, helmets, gloves, toiletries, shoes, camping equipment, tools and other items on the back of a motorcycle. Items may be stored on the shelves of the shelving insert or in various pockets which may be attached to the exterior of the shell. The travel bag maintains the organization of the goods packed by the user, allowing the user ready access to specific desired items without the user having to unpack all of the contents of the bag. This invention allows the user to pack and transport neatly pressed clothing items, without the clothing items becoming excessively wrinkled or disorganized. This invention provides internal reinforcement to a fabric travel bag so that a partially-filled travel bag will not vibrate or flap excessively when the motorcycle is in motion. This bag may be secured to the motorcycle without the need to size the mechanism for the particular model of motorcycle. Rollers or wheels may be mounted on the bottom of the travel bag allowing for easy transportation of the device after it has been removed from the motorcycle. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an isometric view of the subject invention. FIG. 2 shows a side elevational view of the subject invention mounted on the luggage rack of a motorcycle. FIG. 3 shows a side elevational view of the subject invention mounted on the passenger seat-of a motorcycle. FIG. 4 shows an elevational view of the left side of the subject invention. FIG. 5 shows a rear elevational view of the subject invention. FIG. 6 shows a front elevational view of the subject invention, with the flap unfastened, showing how a helmet or other bulky items may be stored. FIG. 7 shows a front elevational view of the subject invention, showing how the shell may be opened from either the top or the bottom. FIG. 8 shows a top view of the subject invention. FIG. 9 shows a bottom view of the subject invention. FIG. 10 shows an isometric view of an alternative embodiment of the subject invention. FIG. 11 shows a left side elevational view of an alternative embodiment of the subject invention. FIG. 12 shows a front elevational view of an alternative embodiment with the flap unfastened. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention comprises a travel bag with shelving insert adaptable for motorcycle transportation. The invention is comprised of two major components, the first component being a heavyweight fabric shell 10 , which may be constructed of a durable, water-resistant, and flexible material, such as CORDURA. The shell 10 provides an enclosure for the second major component, a shelving insert 38 . The shelving insert 38 may be constructed of lightweight rigid materials, such as plastic, aluminum, fiberglass, wood and/or composite materials. Although other shapes are possible, in one embodiment the fabric shell 10 is comprised of a top surface 12 , a bottom surface 14 , a rear surface 16 , a front surface 18 , and two side surfaces 20 , which are joined together in approximately a rectangular prism. Access to the inside of the fabric shell is allowed by activating shell fasteners 36 which may be installed at the seam 32 joining the front surface 18 to the side surfaces 20 . When the shell fasteners 36 are opened, a flap 34 is formed, such as shown in FIG. 6 . As shown in FIG. 7, access to particular portions of the shelving insert 38 is allowed while leaving the flap 34 closed over other portions of the shelving insert to protect items from rain or moisture. Additional components of the fabric shell 10 of the travel bag are security flaps 24 , attached to the rear surface 16 , mounting straps 52 , and corresponding quick clip connectors 54 . A handle strap 56 , mounted rollers 58 and side pockets 62 may also be attached to the fabric shell 10 . The shelving insert 38 is comprised of a top shelf 42 , bottom shelf 44 , side pieces 48 , and intermediate shelves 50 . A back piece 46 may be connected to the back edges of the top shelf 42 , bottom shelf 44 , side pieces 48 and intermediate shelves 50 . The shelving insert 38 may be held within the fabric shell 10 by various insert fasteners 40 such as screws, adhesives, tacks, or hook and loop fasteners, sold under the registered trademark, “Velcro.” If used, hook and loop fasteners may be attached to the inside surfaces of the shell 10 by various means, such as sewing or adhesives. A corresponding hook and loop fastener is attached to the outside surfaces of the shelving insert 38 . Different means may be used for securing the travel bag to the motorcycle. The travel bag may be attached to the motorcycle with security flaps 24 attached to the rear surface 16 of the bag, which wrap around the rear passenger seat back 28 of the motorcycle. Hook and loop fasteners 26 are attached to the security flaps 24 in such a manner as to allow the security flap on one side of the rear surface 16 to fasten to the corresponding security flap of the opposite side of the rear surface. With the bottom surface 14 of the travel bag resting on the motorcycle luggage rack 22 , as depicted in FIG. 2, the security flaps 24 from each side of the rear surface 16 are wrapped tightly around the rear passenger seat back 28 . Unlike pocket devices which must be specifically sized for the dimensions of the specific rear seat back, the security flaps 24 of the present invention are readily adaptable to rear seat backs and sissy bars of different dimensions, by simply adjusting the relative positions of each flap by adjusting the hook and loop fasteners 26 on each security flap. Another means of securing the travel bag to the motorcycle is with mounting straps 52 and respective quick clip connectors 54 attached to the bottom surface 14 and/or lower sections of the rear surface 16 or front surface 18 of the travel bag. The mounting straps 52 , preferably nylon, are wrapped tightly around members of the motorcycle luggage rack 22 , with the ends of the mounting straps being secured into the receiving ends of the quick clip connectors 54 . Both the security flaps 24 and the mounting straps 52 should be used to secure the travel bag to retain the bag firmly in place during travel. When the travel bag is attached to the motorcycle as depicted in FIG. 2, it has the added benefit of providing additional back support for the rear passenger on the motorcycle. An alternative method of attaching the travel bag is available where only one person is on the motorcycle. The bottom surface 14 of the travel bag may be rested upon the rear passenger seat 30 , so that the security flaps 24 are facing toward the rear of the motorcycle as depicted in FIG. 3 . Mounting the travel bag in the manner depicted in FIG. 3 provides additional back support for a single person riding the motorcycle. To mount the travel bag to the motorcycle in this manner, the bag is simply turned around so that the rear surface 16 and the security flaps 24 are oriented to face the rear of the motorcycle, toward the rear passenger seat back 28 . The mounting straps 52 may then be looped around portions of the motorcycle, such as passenger handrail, with the ends of the mounting straps being secured into the receiving ends of the quick clip connectors 54 . In one embodiment, the travel bag has rollers 58 mounted to either the bottom surface 14 , or mounted to the edge of the rear surface 16 adjacent to the bottom surface. The rollers 58 allow the user to roll the bag on the ground after the bag has been dismounted from the motorcycle. The back piece of the shelving insert 46 or and/or the bottom shelf of the shelving insert 44 provide hard surfaces to which the rollers 58 might be attached through the fabric shell 10 by fasteners, such as screws, nails, rivets, or bolts. As an alternative, the rollers 58 may be attached directly to the fabric shell 10 . A handle strap 56 for either lifting the travel bag or pulling the bag along on the rollers 58 is attached to either the top surface 12 or the rear surface 16 of the fabric shell 10 . Side pockets 62 may be attached to the side surfaces 20 to provide additional storage capacity for the user, which may be sized and located for convenience and the configuration of the particular motorcycle. In one embodiment of the travel bag, additional storage volume is provided by increasing the height dimension of the fabric shell 10 so that the volume between the top surface of the fabric shell 10 and the top shelf 42 of the shelving insert 38 is sufficiently enlarged to allow for the storage of larger items inside the travel bag, resting on the top shelf. For example, as depicted in FIG. 6, this space may be used for storage of motorcycle helmets 60 . When this storage volume is not required, the excess fabric may be folded over against the top self of the shelving insert 42 and secured by the top straps 64 to prevent the extra fabric from vibrating or flapping during operation of the motorcycle. In another embodiment of the travel bag, shown in FIGS. 10 through 12, the top surface 12 ′ fits tightly over the top shelf 42 ′ of the shelving insert 38 ′, so there is no available storage volume above the top shelf. Although this embodiment has less storage capacity, the travel bag has a streamlined appearance which may be preferred by some users. This embodiment shares the same features as the first embodiment, such as security flaps 24 ′ attached to the rear surface 16 ′, a front surface 18 ′, and two side surfaces 20 ′, which are joined together in approximately a rectangular prism. Access to the inside of the shell is allowed by opening shell fastener 36 ′ which may be located at the seam 32 ′. Flap 34 ′ is formed when shell fastener 36 ′ is opened. The shelving insert 38 ′ of this embodiment is comprised of a top shelf 42 ′, bottom shelf 44 ′, side pieces 48 ′, and intermediate shelves 50 ′. A back piece 46 ′ may be connected to the back edges of the top shelf 42 ′, bottom shelf 44 ′, side pieces 48 ′ and intermediate shelves 50 ′. The shelving insert 38 ′ may be held within the fabric shell 10 ′ by various insert fasteners 40 ′ such as screws, adhesives, tacks, or hook and loop fasteners. If used, hook and loop fasteners may be attached to the inside surfaces of the shell 10 ′ by various means, such as sewing or adhesives. A corresponding hook and loop fastener is attached to the outside surfaces of the shelving insert 38 ′. Other features of this embodiment are similar to those of the embodiment disclosed in FIGS. 1 through 9. Use of all of the embodiments of the travel bag is simple. With reference to the embodiment disclosed in FIGS. 1 through 9, the user opens the fabric shell 10 by activating shell fasteners 36 , and place his or her clothing and belongings on the intermediate shelves 50 and the bottom shelf 44 of the shelving insert 38 . For this embodiment, items may also be placed on the top shelf 42 . The shell fasteners 36 are activated to close the fabric shell 10 . Additional items may be stored inside the side pockets 62 . Using the handle strap 56 , the user may pull the bag on its rollers 58 to the motorcycle. Lifting the travel bag by the handle strap 56 , the user places the bottom surface 14 on the motorcycle luggage rack 22 or the rear passenger seat 30 . The mounting straps 52 are run beneath the members of the luggage rack 22 and latched into the quick clip connectors 54 , and the ends of the mounting straps pulled to tighten any slack. The security flaps 24 are wrapped around the rear passenger seat back 28 and connected to their opposite member by hook and loop fasteners 26 . Any loose straps should be secured to prevent flapping. The user may then proceed with his or her motorcycle travel, and, upon arriving at the user's destination, perform the above steps in opposite order to remove the travel bag and unload the user's belongings. Although the subject invention has been described and illustrated in detail, those skilled in the art appreciate that various adaptions and modifications of the preferred embodiments can be configured without departing from the spirit and scope of thee invention. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims.

A motorcycle travel bag comprising a shell and a shelving insert, wherein the shelving insert provides a convenient and secure apparatus for organizing, storing and transporting various items on a motorcycle. Items may be stored on the shelves of the shelving insert or in various pockets which may be attached to the exterior of the shell.

This is a continuation, of application Ser. No. 134,009 filed Mar. 26, 1980, now abandoned. BACKGROUND OF THE INVENTION This invention relates to a composition for use in the production of foamable sheet material, which sheet material may be fabricated into carriers, for attachment to cylindrical containers. More specifically, the invention relates to a composition which provides a reduction in weight to the sheet material without a corresponding reduction in specific properties of the fabricated carrier. Carriers used heretofore for attachment below the chimes of cylindrical containers have seen wide spread use by industry and have gained wide acceptance by the consuming public. The light weight character and durability of plastic carriers have provided numerous advantages over paper carriers. However, minimum thickness levels for unfoamed sheet material for fabrication into carriers and handability by machines is required, and the properties of the sheet material were more than necessary. To overcome the problem of "wasting" properties and/or having to alter machinery to handle thinner sheet material, attempts have been made to moderately or heavily foam the sheet material. As anticipated, another problem arose regarding degradation of properties, such that the carriers produced were not suitable for use, especially with regard to tear propagation properties. The lightly foamed sheet material of this invention has properties within the specifications required of unfoamed sheet material as a carrier for cylindrical containers. It is lighter in weight, it reduces raw material requirements and provides enhanced tear properties over unfoamed or moderate/heavily foamed sheet material. One advantage then of the present invention is that a lighter weight sheet material is formed which is usable in the fabrication of carriers for cylindrical containers on existing equipment, without a corresponding loss in properties. Another advantage of the present invention is the reduction in the amount of raw materials per sheet material or carrier produced. Yet another advantage of the present invention is improved tear resistance and resistance to propagation of tears once commenced for the sheet material or carrier produced. One feature of the present invention is the use of a blowing agent mixture to obtain the foamed, lighter weight sheet material when the composition is extruded on existing equipment. Still another feature of the present invention is that scrap sheet material, obtained during fabrication of the carriers can be chopped and reused in the composition without adversely affecting the properties or performance of the carrier. SUMMARY OF THE INVENTION The present invention comprises a composition which provides a lightly foamed sheet material which yields approximately 10 to 20 percent reduction in density over unfoamed sheet material, without a corresponding percentage reduction in properties. DESCRIPTION OF THE PREFERRED EMBODIMENT The composition of this invention finds particular utility in the manufacture of sheet material, which is primarily used in the fabrication of carriers for cylindrical containers, of the type shown in U.S. Pat. Nos. 3,773,100 and 3,874,502. Such carriers are made from resilient, deformable, unsupported plastic sheet material, wherein a high percentage of the sheet material remains as scrap, during fabrication of the carriers and wherein the carriers are generally machine applied to containers thus requiring a fast response time between the stretching and the gripping of the carriers about the containers during production applications. Further, the carriers must possess requisite strength to prevent the containers from slipping or dropping from the carrier during handling by the manufacturer, distributors, retailers, and consumers. These requirements indicate the necessity for any substitute composition to be usable on existing equipment, to keep the properties within specifications required for carriers and to allow scrap material to be reworked within the composition. Therefore with a foamed structure, it becomes crucial that for a specific density reduction, of about 10-20 percent by weight, over an unfoamed structure, the properties are not proportionately reduced, but remain within established specifications, despite the fact that the foamed structure has cells distributed therein. Carriers of the type described in the above-mentioned U.S. Patents must possess certain characteristics to be functional during processing, such as during machine application of carriers to containers, and during handling and shipping, when in combination with containers. Some of these characteristics include the properties of impact resistance, coefficient of friction, ductility, tear resistance, environmental stress cracking resistance, elastic modulus, yield stress, yield strain, ultimate strength and ultimate elongation. The composition of ingredients used in the manufacture of sheet material employed for the fabrication of carriers, in the main, controls and/or establishes the desired balance of the above properties. The processing equipment used in the manufacture of the sheet material, primarily the extrusion head and advancing rolls, presently have parameters which limit the thinness of the sheet material being produced. It has been known for some time that the present equipment parameters and present composition parameters produce sheet material on carriers exhibiting properties in excess of actual requirements. This excess of properties per sheet material or carrier represents waste, which heretofore has been reluctantly accepted. Attempts to alter equipment parameters, eg. to reduce the thickness of the sheet material has been met with problems. Likewise, attempts to alter the composition have heretofore not been successful, as all of the properties would not be within specifications. The present invention takes into account the parameters of the equipment and the difficulties in altering the ingredients of the composition, by introducing a blowing agent and mineral oil into the composition. A slightly foamed sheet material is produced at a thickness within equipment parameters and having properties within established specifications. By slightly foaming the sheet material, not only is the structure lighter in weight, and a reduction in raw material requirements noted, but the properties of the foamed sheet material do not correspond on a percentage basis to the density reduction. In fact, it has been found, quite unexpectedly, that resistance to tears and to propagation of tears once commenced is markedly improved in the slightly foamed structure. The slightly foamed structure provides a reduction in density of approximately 10-20 percent over an unfoamed structure of the same thermoplastic polymer. Preferably the density reduction in the slightly foamed structure is approximately 13-17 percent over an unfoamed structure. The density of the foamed structure of the present invention ranges from about 45 lb/ft 3 to about 55 lb/ft 3 , and preferably ranges from about 48 lb/ft 3 to about 52 lb/ft 3 . The thickness of the structures, foamed and unfoamed are from about 0.014 to about 0.018 inches, the present day parameters of the equipment used to extrude and process the structures. The slightly foamed structure of the present invention exhibits uniformly distributed or disbursed closed gas filled cells entrained within the structure. The gas filled cells are extremely small (of the order of magnitude of about 200 microns) diameter and they are barely visible with the naked eye. The surfaces of the foamed structure appear to be as smooth and uninterrupted as the unfoamed structure, thereby exhibiting similar aesthetic qualities of the latter, including resistance to soiling. The tiny cells within the structure apparently disrupt the normal planes of tear in an unfoamed structure. Unfoamed structures, eg. of extruded polyethylene, exhibit oriented molecules and tearing normally occurs alongside these molecules. By slightly foaming a structure, the bubbles apparently cause disruptions along the planes of tear and thus alters the orientation of the molecules. This alteration apparently causes applied stress to the foamed structure to dissipate within the structure, thus enhancing resistance to tear. The condition that the cells be closed and entrained within the structure is in addition to other conditions--the bubble size and the density of the bubbles. If the cell size or bubble size is allowed to grow and expand to the point of bursting, properties, especially resistance to tear are adversely affected. Likewise, if the density of the cells increases beyond about 100-500 cells/cm 3 , the resistance to tear is adversely affected. Generally, the cell size and density of the cells are a function of the amount and of the nature of the blowing agent or mixture of blowing agents employed within the composition. The temperature at which the blowing agents release an inert gas, such as nitrogen, is a controlling factor, thus the temperatures generated during extrusion must be tightly controlled. For a composition employing a blowing agent which releases an inert gas at about 325° F., the temperature range during extrusion must be controlled to about ±5° F. The composition of the present invention which enables the production of slightly foamed sheet material for use in fabrication of carriers is represented as shown below. EXAMPLE I ______________________________________Ingredients Amount (pounds)______________________________________Low density thermoplastic polymer 90-110Blowing agent mixture 0.05-0.4Mineral oil 0.05-0.2______________________________________ EXAMPLE II ______________________________________Ingredients Amount (pounds)______________________________________Low density thermoplastic polymer 95-105Blowing agent mixture 0.15-0.25Mineral Oil 0.07-0.13______________________________________ The low density thermoplastic polymer may be polyethylene and copolymers thereof or polypropylene and copolymers thereof. Generally, a low density polyethylene polymer having a number average molecular weight (Mn) of from about 22,000 to about 30,000 is preferred. Such polymers are commercially available from Union Carbide Corp. and U.S. Industrial Chemicals Corp. The blowing agent mixture comprises blowing agents which release an inert gas at about 300° F.-400° F., such as azodicarb-onamides commercially available as "Kempore", and additives such as Metal Oxide as contained in commercially available in Kempore Mc. The mineral oil may be any laboratory light grade oil commercially available from Standard Oil Co. EXAMPLES III-V ______________________________________ Amounts (pounds)Ingredients III IV V______________________________________Low density polyethylene polymer 100. 100 100Blowing agent mixture 0.2 .25 .15Mineral Oil 0.1 .13 .07______________________________________ The mixing procedure for the above examples comprises combining the polyethylene polymer, generally used in pellet form, and the mineral oil so that the latter coats the former. Thereafter the blowing agent mixture, generally used in powder form, is combined with the coated pellets to evenly distribute the ingredients of the mixture. The mixtures of the above examples were fed to an extrusion machine previously used to produce unfoamed sheet, wherein the temperature range during extrusion was maintained within ±5° F. of the gasifying temperature of the blowing agent mixture. Foamed sheets were formed and carriers for containers were obtained therefrom, which were machine applied to cylindrical containers with favorable results. The densities of the resulting foamed sheets for Examples III, IV, V, were 50 lb/ft 3 , 45 lb/ft 3 , and 52 lb/ft 3 respectively. During the fabrication of carriers from the sheet material much scrap is generated, i.e. about 75-80% scrap is generated. Because of this feature, the scrap must be reworked into the basic composition for the material to be feasible in industrial applications. Generally, the scrap is chopped, and is called "fluff" in the industry. This fluff is then added to the basic composition mixture and the mixture and the fluff are combined in a blender prior to being fed to an extrusion machine as described above. It has been found that the chopped scrap sheet material can be present in the composition in an amount of from about 10.0 to about 90.0 percent by weight of the total weight of the thermoplastic polymer and the chopped scrap sheet material. Preferably, the chopped scrap sheet material is present in an amount of from about 60.0 to about 80.0 percent by weight of the total weight of the thermoplastic polymer and the chopped scrap sheet material. There appears to be no limitation on the number of times the scrap may be reworked into the composition. The following examples represent compositions of this invention, employing chopped scrap sheet material, used in the production of slightly foamed structures. EXAMPLE VI ______________________________________Ingredients Amount (pounds)______________________________________Low Density Thermoplastic Polymer 10-90Chopped Scrap Sheet Material 10-90Blowing Agent Mixture 0.02-0.4Mineral Oil 0.01-0.2______________________________________ EXAMPLE VII ______________________________________Ingredients Amount (pounds)______________________________________Low Density Thermoplastic Polymer 20-40Chopped Scrap Sheet Material 60-80Blowing Agent Mixture 0.05-0.15Mineral Oil 0.02-0.07______________________________________ EXAMPLES VIII-X ______________________________________ Amount (pounds)Ingredients VIII IX X______________________________________Low Density Thermoplastic Polymer 30. 40. 20.Chopped Scrap Sheet Material 70. 60. 80.Blowing Agent Mixture 0.07 .15 .05Mineral Oil 0.03 .07 .02______________________________________ The mixing procedure for the above examples comprises combining the polyethylene polymer and the mineral oil, so that the mineral oil coats the polymer, usually in the form of pellets to assure that the subsequently combined blowing agent mixture is substantially uniformily applied to the oil coated pellets. The blowing agent mixture is generally employed in a powder or granular form, thereby requiring substantial mixing with the oil coated pellets. Subsequently, the mixture of polymer, oil, and blowing agent is combined with chopped scrap sheet material (fluff) for blending or mixing. Thereafter, the blended ingredients are fed to an extruder to produce a foamed structure. Carriers of the type hereinabove described and referred to were fabricated from the foamed structures, and the carriers were machine applied to cylindrical containers in a satisfactory manner. The properties of the foamed carriers were within the prescribed specifications of unfoamed carriers, and they matched the performance of unfoamed carriers produced from low density polyethylene polymer. However, the foamed carriers were found to have better resistance to tear and better resistance to propagation of tear once commenced. The densities of the resulting foamed structures for Examples VIII, IX, X were 50 lb/ft.sup. 3, 48 lb/ft 3 , and 52 lb/ft 3 respectively. The scrap sheet material thus formed during fabrication of the foamed sheet of the above examples into carriers can again be chopped and reused. Modifications of the disclosed compositions and sheet material produced therefrom may be resorted to without departing from the spirit and scope of the appended claims.

A foamed low density polyethylyne sheet material is provided which finds utility in the fabrication of carriers for attachment to cylindrical containers. The sheet material is formed from a composition comprising low density polyethelyne polymer, a blowing agent mixture, and mineral oil, on commercially available extrusion equipment, and in proportions sufficient to obtain a 10-20 percent reduction in weight without a corresponding reduction of specific properties.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to co-pending and commonly-assigned patent application Ser. No. 09/494,325, filed on Jan. 28, 2000, by Cynthia M. Saracco, entitled “TECHNIQUE FOR DETECTING A SHARED TEMPORAL RELATIONSHIP OF VALID TIME DATA IN A RELATIONAL DATABASE MANAGEMENT SYSTEM,” which application is incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to relational database management systems, and, in particular, to a technique for detecting a subsuming temporal relationship of valid time data in a relational database management system. 2. Description of Related Art Databases are computerized information storage and retrieval systems. A Relational Database Management System (RDBMS) is a database management system (DBMS) which uses relational techniques for storing and retrieving data. Relational databases are organized into tables which consist of rows and columns of data. The rows are formally called tuples. A database will typically have many tables and each table will typically have multiple tuples and multiple columns. The tables are typically stored on random access storage devices (RASD) such as magnetic or optical disk drives for semi-permanent storage. RDBMS software using a Structured Query Language (SQL) interface is well known in the art. The SQL interface has evolved into a standard language for RDBMS software and has been adopted as such by both the American National Standards Institute (ANSI) and the International Standards Organization (ISO). The SQL interface allows users to formulate relational operations on the tables either interactively, in batch files, or embedded in host languages, such as C and COBOL. SQL allows the user to manipulate the data. A data warehouse is a combination of many different databases across an entire enterprise. Data warehouses contain a wide variety of data that presents a coherent picture of business conditions at a single point in time. As a result, many companies use data warehouses to support management decision making. A data mart is similar to a data warehouse. The only difference between the data mart and the data warehouse is that data marts are usually smaller than data warehouses, and data marts focus on a particular subject or departments. Both the data warehouse and the data mart use the RDBMS for storing and retrieving information. Companies frequently use data warehouses and data marts to create billions of bytes of data about all aspects of a company, including facts about their customers, products, operations, and personal. Many companies use this data to evaluate their past performance and to plan for the future. To assist the companies in analyzing this data, some data warehousing and decision support professionals write applications and generate reports that seek to shed light on a company's recent business history. Several common forms of data analysis involve evaluating time-related data, such as examining customer buying behaviors, assessing the effectiveness of marketing campaigns or determining the impact of organizational changes on sales during a selected time period. The relevance of time-related data to a variety of business applications has caused some DBMS professionals to reexamine the need for temporal data analysis. Temporal data is often used to track the period of time at which certain business conditions are valid. To illustrate, a company may sell product X for: $50 during a first period of time; $45 during a second period of time; and $52 during a third period of time. The company may even know that this same product will sell for $54 during some future period of time. When the company's database contains information about the valid times for each of these price points, the pricing points are referred to as temporal data. Common techniques for recording valid time information in a RDBMS involve including a DATE column in a table that tracks business conditions, such as a START_DATE and an END_DATE column in a table that tracks pricing information for products. Analyzing temporal data involves understanding the manner in which different business conditions relate to one another over time. Returning to the previous example, each product has a retail price for a given period of time, and each product also has a wholesale cost. Retail prices can fluctuate independently of the product's wholesale cost, and vice versa. To determine efficiencies (or inefficiencies) in a product's pricing scheme, a retailer may wish to understand the relationship between a product's retail price and a product's wholesale cost over time. More specifically, a retailer may wish to evaluate: whether products are being placed on sale at inopportune times (e.g., before the retailer is eligible to receive a reduction in wholesale price) or whether the retailer has failed to pass on cost savings to customers (e.g., failing to place products on sale during the period in which their wholesale cost is reduced). These questions involve temporal analysis because the questions involve tracking the period of time at which certain business conditions were in effect. These questions can be challenging to express in SQL, and many users are incapable of correctly formatting such SQL queries. Further, mistakes in the SQL query are common and difficult to detect. Thus, there is a need in the art for a technique of creating a simplified SQL query to analyze the temporal relationships of various business conditions. SUMMARY OF THE INVENTION To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a method, apparatus, and article of manufacture for detecting subsuming temporal relationships in a relational database. In accordance with the present invention, an invocation of a within operation that specifies a first event and a second event is received. In response to the invocation, a combination of temporal relationships between the first event and the second event is evaluated to determine (1) whether the second event starts at the same time as the first event or whether the second event starts before the first event and (2) whether the second event ends at the same time as the first event or whether the second event ends after the first event. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings in which like reference numbers represent corresponding parts throughout: FIG. 1 schematically illustrates a hardware environment of a preferred embodiment of the present invention; FIG. 2 illustrates seven temporal relationship operators; and FIGS. 3A-3B are flow charts that illustrate the steps performed by the single function operator system in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized as structural changes may be made without departing from the scope of the present invention. Hardware Environment FIG. 1 illustrates a computer hardware environment that could be used in accordance with the present invention. In the exemplary environment, a computer system 102 is comprised of one or more processors connected to one or more data storage devices 104 and 106 that store one or more relational databases, such as a fixed or hard disk drive, a floppy disk drive, a CDROM drive, a tape drive, or other device. Operators of the computer system 102 use a standard operator interface 108 , such as IMS/DB/DC®, CICS®, TSO®, OS/390®, ODBC® or other similar interface, to transmit electrical signals to and from the computer system 102 that represent commands for performing various search and retrieval functions, termed queries, against the databases. In the present invention, these queries conform to the Structured Query Language (SQL) standard, and invoke functions performed by Relational DataBase Management System (RDBMS) software. The SQL interface has evolved into a standard language for RDBMS software and has been adopted as such by both the American National Standards Institute (ANSI) and the International Standards Organization (ISO). The SQL interface allows users to formulate relational operations on the tables either interactively, in batch files, or embedded in host languages, such as C and COBOL. SQL allows the user to manipulate the data. In the preferred embodiment of the present invention, the RDBMS software comprises the DB2® UDB V5.2 product offered by IBM for the Windows NT 4.0 operating systems. Those skilled in the art will recognize, however, that the present invention has application program to any RDBMS software, whether or not the RDBMS software uses SQL. As illustrated in FIG. 1, the DB2® UDB V5.2 system for the Windows NT 4.0 operating system includes three major components: the Internal Resource Lock Manager (IRLM) 110 , the Systems Services module 112 , and the Database Services module 114 . The IRLM 110 handles locking services for the DB2® UDB V5.2 system, which treats data as a shared resource, thereby allowing any number of users to access the same data simultaneously. Thus concurrency control is required to isolate users and to maintain data integrity. The Systems Services module 112 controls the overall DB2® UDB V5.2 execution environment, including managing log data sets 106 , gathering statistics, handling startup and shutdown, and providing management support. At the center of the DB2® UDB V5.2 system is the Database Services module 114 . The Database Services module 114 contains several submodules, including the Relational Database System (RDS) 116 , the Data Manager 118 , the Buffer Manager 120 , the Rebalancing System 124 , and other components 122 such as an SQL compiler/interpreter. These submodules support the functions of the SQL language, i.e. definition, access control, interpretation, compilation, database retrieval, and update of user and system data. The Single Function Operator System 124 works in conjunction with the other submodules to provide a single function operator that simplifies the process of detecting and tracking subsuming temporal relationships. The present invention is generally implemented using SQL statements executed under the control of the Database Services module 114 . The Database Services module 114 retrieves or receives the SQL statements, wherein the SQL statements are generally stored in a text file on the data storage devices 104 and 106 or are interactively entered into the computer system 102 by an operator sitting at a monitor 126 via operator interface 108 . The Database Services module 114 then derives or synthesizes instructions from the SQL statements for execution by the computer system 102 . Generally, the RDBMS software, the SQL statements, and the instructions derived therefrom, are all tangibly embodied in a computer-readable medium, e.g. one or more of the data storage devices 104 and 106 . Moreover, the RDBMS software, the SQL statements, and the instructions derived therefrom, are all comprised of instructions which, when read and executed by the computer system 102 , causes the computer system 102 to perform the steps necessary to implement and/or use the present invention. Under control of an operating system, the RDBMS software, the SQL statements, and the instructions derived therefrom, may be loaded from the data storage devices 104 and 106 into a memory of the computer system 102 for use during actual operations. Thus, the present invention may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” (or alternatively, “computer program product”) as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. Of course, those skilled in the art will recognize many modifications may be made to this configuration without departing from the scope of the present invention. Those skilled in the art will recognize that the exemplary environment illustrated in FIG. 1 is not intended to limit the present invention. Indeed, those skilled in the art will recognize that other alternative hardware environments may be used without departing from the scope of the present invention. Single Function Operator System The growing interest in advanced data analysis techniques—prompted, in part, by increased use of data warehouses, data marts, and other decision support environments—has led some DBMS professionals to revisit the need for temporal data analysis. Such analysis attempts to discern the manner in which the states of things (e.g., product content, product pricing, product promotions, product management, etc.) vary over time and the manner in which these different states may be inter-related. For example, a product may sell at its standard retail price for certain periods of time, while at other times it may sell at various discounted rates. Furthermore, this same product may cost the retailer different prices at different periods of time (perhaps due to a manufacturer's rebate offer). Understanding the relationship between the product's various states of pricing can be important when determining the effectiveness of the product's pricing strategy and assessing profits on the product's sales. The examples discussed herein involve retail-oriented databases with a star schema architecture. The retail industry is used because of its commercial significance in the data warehousing and decision support fields and because members of the retail industry tend to be interested in temporal analysis. However, the single function operator system 124 is applicable to other industries. Some forms of temporal analysis are challenging to express using current commercial technology. Researchers have argued that these commercial limitations may place an undue burden on DBMS users in the future, as data warehouses are likely to store greater quantities of historical data. Temporal data tracks state-related information. This often translates into recording the time period for which a given condition was (or is or will be) valid. An example of temporal data is shown below in Table 1 and Table 2. Specifically, Table 1 and Table 2 contain information about Grace Theophila's salary and job titles over time. Grace Theophila is a fictional employee. Date information is shown in the MM/DD/YYYY format. TABLE 1 ID NAME SALARY START_DATE END_DATE 123 Grace Theophila 45,000 Feb. 01, 1997 Apr. 20, 1998 123 Grace Theophila 48,000 Apr. 20, 1998 Oct. 30, 1998 123 Grace Theophila 49,500 Oct. 30, 1998 Apr. 04, 1999 ... ... ... ... ... TABLE 2 START — ID NAME TITLE DATE END_DATE 123 Grace Theophila Asst Feb. 01, 1997 Dec. 01, 1997 Manager 123 Grace Theophila Manager Feb. 01, 1997 Apr. 04, 1999 ... ... ... ... ... Both Table 1 and Table 2 track valid time information about different business conditions. Table 1 records salary information for employees throughout various periods of time, and Table 2 records employees'job titles throughout various periods of time. The “period” nature is a characteristic of temporal data and temporal analysis. Traditional databases (i.e., databases which focus on currently valid data) rarely model employee salary and job title information in two separate tables, as shown in Table 1 and Table 2. However, for simplicity, a “temporal” database (i.e., one which attempts to track historical information and, possibly, current and future information as well) may model data in separate tables. An employee's salaries and job titles can vary over time, independently of one another. Storing both pieces of information in a single temporal table forces the DBMS professional to design the database in the following manner either: (1) retain only one start/end date pair to record the valid time for all the row's content; or (2) include multiple start/end date pairs, each recording the valid time for a single part of the row's content. Each of these design options increases the complexity of the temporal analysis. Therefore, in the interest of simplicity and clarity, the single function operator system 124 will be described herein with respect to separate tables for each type of data. However, if desired, the single function operator system 124 can be used with other database designs, e.g., single table designs. Both Table 1 and Table 2 use dates as their level of temporal granularity, because presumably, an employee's salary or job title remains constant for a single day. However, temporal data can be recorded at coarser or finer levels of granularity. The START_DATE represents the first day on which the condition became true, and the END_DATE represents the first day thereafter in which the condition failed to remain true. For example, beginning Feb. 1, 1997, Grace had a salary of $45,000 per year. Grace continued to earn this salary until—but not including—Apr. 20, 1998. This technique of modeling temporal data is sometimes referred to as a “closed-open” representation in research literature. Of course, other representations of the data are possible without exceeding the scope of the single function operator system 124 . Many of the underlying principles for a preferred embodiment of the single function operator system 124 are based on the theoretical work of J. F. Allen, who identified a set of operators (commonly referred to as Allen's operators) that can be used to assess temporal relationships. Allen's operators can be expressed in a variety of languages, including SQL. Allen's operators are shown in FIG. 2 . FIG. 2 has an OPERATOR column 200 , a RELATIONSHIP column 202 , and a GRAPHIC EXAMPLE column 204 . The OPERATOR column 200 contains seven of Allen's operators, including BEFORE 206 , MEETS 208 , OVERLAPS 210 , DURING 212 , STARTS 214 , FINISHES 216 , and EQUAL 218 . These operators 206 , 208 , 210 , 212 , 214 , 216 , and 218 perform a comparison operation. The result of each comparison operation yields a TRUE or FALSE value. The RELATIONSHIP column 202 shows the relationship between a time period X 220 and a time period Y 222 . The GRAPHIC EXAMPLE column 204 displays a graphical representation of the relationship between the time period X 220 and the time period Y 222 . Other of Allen's operators include MET BY, OVERLAPPED BY, STARTED BY, and FINISHED BY. The results of these operators also produce a TRUE or FALSE value. The preferred embodiment of the single function operator system 124 combines some of the operators 206 , 208 , 210 , 212 , 214 , 216 , and 218 into a single function. Combining some of the operators 206 , 208 , 210 , 212 , 214 , 216 , and 218 simplifies certain queries and helps reduce the number of lines of SQL code. More specifically, an embodiment of the single function operator system 124 provides a WITHIN operator that combines the EQUAL 218 , DURING 212 , STARTS 214 , and FINISHES 216 operators into a single function operator. The WITHIN operator returns a TRUE value when the time period X 220 is wholly or partly contained (or subsumed) within the time period Y 222 . Another embodiment of the present invention provides a SHARES operator. The SHARES operator is similar to the WITHIN operator. Like the WITHIN operator, the SHARES operator combines the EQUAL 218 , DURING 212 , STARTS 214 , and FINISHES 216 operators into a single function operator. The difference between the WITHIN operator and the SHARES operator is that the SHARES operator adds the following operators to the combination: OVERLAPS 210 , OVERLAPPED BY, CONTAINS, STARTED BY, and FINISHED BY. The SHARES operator returns a TRUE value when time period X 220 shares any time in common with time period Y 222 . To illustrate the benefits of the SHARES operator, the SHARES operator is used to extract data from Table 3 and Table 4 . Table 3 represents a Store database. The Store database records data about stores and the districts to which each store reports. Table 3 contains five columns, a SID column, a STORE_NAME column, a DID column, a ORG_START column, and ORG_END column. The SID column contains a store identifier. The STORE_NAME column contains the name of store. The DID column contains the district identifier of the district that the store reports to. The ORG_START column contains the start date of the store-to-district reporting structure, and the ORG_END column contains the end date of the store-to-district reporting structure. TABLE 3 SID STORE_NAME DID ORG_START ORG_END 0 Acme 0 7 May 06, 1998 July 20, 1998 0 Acme 0 6 Jan. 01, 1998 May 06, 1998 1 Acme 1 7 Apr. 20, 1998 May 05, 1998 2 Acme 2 6 Jan. 01, 1998 Sep. 30, 1998 2 Acme 2 7 Sep. 30, 1998 Dec. 30, 1998 3 Acme 3 5 Jan. 10, 1998 Dec. 30, 1998 4 Acme 4 5 Sep. 01, 1998 Dec. 30, 1998 ... ... ... ... ... Table 4 represents a District database. The District database records data about the districts and about the districts associated trading area. Table 4 contains five columns: a DID column that contains a district identifier; a D_NAME column that contains a district name; a TID column that contains an identifier of the trading area that the districts reports to; an ORG_START column that contains a start date of the reporting structure, and an ORG_END column that contains an end date of the reporting structure. TABLE 4 DID D_NAME TID ORG_START ORG_END 5 Valley District 11 Jan. 01, 1998 July 30, 1998 6 Springs District 11 May 30, 1998 Dec. 30, 1998 6 Lakes District 12 Jan. 01, 1998 May 30, 1998 7 Mountain District 12 Feb. 04, 1998 Nov. 30, 1998 5 Willows District 12 July 30, 1998 Aug. 30, 1998 6 Waterfront District 9 Jan. 01, 1997 Dec. 30, 1997 ... ... ... ... ... As an example, assume that a query seeks to report the names of stores and the districts which the stores are associated with over time. This type of query is sometimes referred to as a “temporal sequenced join”. Such a query might produce a report that cites the name of each store, the name of the district into which the store reported, and the dates for which this store-to-district reporting information is valid. Table 5 represents a sample result. TABLE 5 STORE_NAME D_NAME ORG_START ORG_END Acme 0 Lakes District Jan. 01, 1998 May 06, 1998 Acme 0 Mountain District May 06, 1998 July 20, 1998 Acme 1 Mountain District Apr. 20, 1998 May 05, 1998 Acme 2 Lakes District Jan. 01, 1998 Sep. 30, 1998 Acme 2 Springs District Jan. 01, 1998 Sep. 30, 1998 Acme 2 Mountain District Sep. 30, 1998 Dec. 30, 1998 Acme 3 Valley District Jan. 10, 1998 Dec. 30, 1998 Acme 3 Willows District Jan. 10, 1998 Dec. 30, 1998 Some conventional techniques for drafting a query that produces the results contained in Table 5 require four SELECT statements, three UNION statements, and a total of eleven data comparison operations. Each SELECT statement tests for some relationship between the time period of validity for the store-to-district reporting structure. The data comparison operators, which implement Allen's operators, test for various temporal relationships. After testing for the temporal relationships, the query then unions the results together. A sample conventional query is shown below: SELECT store_name, d_name, store.org_start, store.org_end FROM store, district WHERE store.did=district.did and district.org_start<=store.org_start and store.org_end<=district.org_end UNION SELECT store_name, d_name, store.org_start, store.org_end FROM store, district WHERE store.did=district.did and store.org_start>district.org_start and district.org_end<store.org_end and store.org_start<district.org_end UNION SELECT store_name, d_name, store.org_start, store.org_end FROM store, district WHERE store.did=district.did and district.org_start>store.org_start and store.org_end<district.org_end and district.org_tart<store.org_end UNION SELECT store_name, d_name, store.org_start, store.org_end FROM store, district WHERE store.did=district.did and district.org_start>=store.org_start and district.org_end<=store.org_end ORDER BY store_name The above query contains four query blocks. Each section of the query that begins with a SELECT statement is a query block. Each query block contains a standard join clause based on the district identification number (i.e., the DID column of the STORE and DISTRICT tables). Each query block also includes a temporal join clause. To simplify the discussion of the temporal join clauses, assume “P 1 ” denotes the time period specified by the ORG_START and ORG_END dates of the STORE table shown in Table 3, and assume “P 2 ” denotes the time period specified by the ORG_START and ORG_END dates of the DISTRICT table shown in Table 4. Thus, the four query blocks test for the following temporal conditions: Query Block 1 : P 1 DURING P 2 or P 1 EQUAL P 2 or P 1 STARTS P 2 Query Block 2 : P 2 OVERLAPS P 1 Query Block 3 : P 1 OVERLAPS P 2 Query Block 4 : P 2 DURING P 1 or P 2 EQUAL P 1 or P 2 FINISHES P 1 While this query produces the intended result set shown in Table 5, many users would experience difficulty formulating this query. In particular, few users are capable of developing the logic and correctly coding the syntax (particularly all the date comparison operators) in a timely manner. Assuming that users store their temporal data in a relational or object/relational DBMS, a user must perform the following steps to formulate the above query: (1) understand the logic of each of the relevant temporal conditions; (2) correctly translate the logic into SQL date comparison operators; (3) formulate appropriate query blocks; and (4) UNION these query blocks together. Such query logic can be difficult to debug, as an error in one date comparison operator will yield incorrect results. However, that same error will fail to produce an error warning message from the database. In addition to the difficulty in formulating and debugging the SQL query, the execution of the SQL query can cause a database management system to scan the table(s) referenced in the query multiple time (one time for each query block). Such scanning may result in considerable input and output processing and poor performance (e.g., delays in receiving query results). Fortunately, the single function operator system 124 provides the SHARES operator. The SHARES operator simplifies the above query. More specifically, the SHARES operator eliminates three of the four SELECT statements, all of the UNION statements, and ten of the eleven date comparisons. Using the SHARES operator, the above query can be revised as follows: SELECT store_name, store.did, d_name, store.org_start, store.org_end FROM store, district WHERE store.did=district.did and shares(store.org_start, store.org_end, district.org_start, district.org_end)=1 ORDER BY store_name, store.did In addition to greatly simplifying the traditional query, the revised query adds a the district identifier (the DID column of Table 4) to the result shown in Table 6. TABLE 6 STORE — NAME DID D_NAME ORG_START ORG_END Acme 0 6 Lakes District Jan. 01, 1998 May 05, 1998 Acme 0 7 Mountain District May 06, 1998 July 20, 1998 Acme 1 7 Mountain District Apr. 20, 1998 May 05, 1998 Acme 2 6 Springs District Jan. 01, 1998 Sep. 30, 1998 Acme 2 6 Lakes District Jan. 01, 1998 Sep. 30, 1998 Acme 2 7 Mountain District Sep. 30, 1998 Dec. 30, 1998 Acme 3 5 Valley District Jan. 10, 1998 Dec. 30, 1998 Acme 3 5 Willows District Jan. 10, 1998 Dec. 30, 1998 In the revised query, the operator that eliminates the most code is the SHARES OPERATOR: shares(store.org_start, store.org_end, district.org_start, district.org_end)=1 The SHARES function combines several temporal tests into one. A temporal relationship exists when either time period is equal to the other time period, or overlaps with the other time period, or occurred during the other time period, or starts during the other time period, or finishes during the other time period. That is, the two periods share some time in common. The SHARES operator expects to receive four DATE values as input (each pair containing the start/end points of each time period). The SHARES operator returns a “1” if the test evaluates as TRUE or a “0” if the test evaluates as FALSE. The WITHIN operator also eliminates the amount of code used in a traditional query. To illustrate the benefit of using the WITHIN operator, the WITHIN operator is used to extract data from Table 7 and Table 8 below. Table 7 represents a Discount database. The discount database records the retail price discount offered by store for products. Table 7 contains five columns: a PID column, a SID column, a PERCENT_OFF column, a D_START column, and a D_END column. The PID column contains a product identifier. The SID column contains a store identifier. The PERCENT_OFF column contains a discount rate. The D_START column contains a start time for a discount on product. The D_END columns contains the end time for a discount on product. TABLE 7 PID SID PERCENT_OFF D_START D_END 100 3 5 May 01, 1998 May 30, 1998 200 1 7 Apr. 30, 1998 May 10, 1998 200 2 7 Apr. 30, 1998 May 10, 1998 600 2 5 Nov. 30, 1998 Dec. 05, 1998 500 0 10 Feb. 01, 1998 Feb. 10, 1998 ... ... ... ... ... Table 8 represents a Manu_Special database. The Manu_Special database records a manufacturer's discount offered to retailers. Table 8 contains four columns, a PID column, a PERCENT_OFF column, a S_START column, and a S_END column. The PID column contains the product identifier. The PERCENT_OFF column contains manufacturer's discount rate. The S_START column contains the start date of manufacturer's special pricing. The S_END column contains the end date of manufacturer's special pricing. TABLE 8 PID PERCENT_OFF S_START S_END 100 2 Apr. 30, 1998 May 15, 1998 100 5 July 30, 1998 Aug. 15, 1998 400 10 July 30, 1998 Aug. 30, 1998 600 5 Dec. 10, 1998 Dec. 30, 1998 500 15 Jan. 01, 1998 Feb. 15, 1998 ... ... ... ... A sample query is shown below. The query seeks to determine which products were put on sale during a time period X 220 , wherein the time period X 220 occurs outside of the time period Y 222 . The time period Y 222 represents the time period in which the store was eligible to receive a manufacturer's rebate. In other words, the query seeks to determine if any portion of a product's retail discount period fell outside the manufacturer's rebate period. SELECT discount.pid, sid, d_start as disc_start, d_end as disc_end, s_start as rebate_start, s_end as rebate_end FROM discount, manu_special WHERE discount.pid=manu_special.pid and ((d_start<s_start) or (d_end>s_end)) The query contains one query block. The query block contains a standard join clause based on the product identification number (i.e., the PID column of the Discount and Manu_Special tables). The query block also includes a temporal join clause. Formulating this temporal join clause is difficult because correct date comparison operations must be specified. In this example, the goal is to produce a result that contains discounted products that fell outside the manufacturer's rebate period—that is, any discounts occurring before or after the rebate period. To simplify the discussion of the temporal join clauses, assume “P 1 ” denotes the time period specified by the D_START and D_END dates of the Discount table shown in Table 7, and assume “P 2 ” denotes the time period specified by the S_START and S_END dates of the Manu Special table shown in Table 8. While this query produces the intended result set, many people would experience difficulty formulating this query. In particular, few people are capable of developing the logic and correctly coding the syntax (particularly the date comparison operators) in a timely manner. The WITHIN operator simplifies the above query. Using the WITHIN operator, the above query can be revised as follows: SELECT discount.pid, sid, d_start as disc_start, d_end as disc_end, s_start as rebate_start, s_end as rebate_end FROM discount, manu_special WHERE discount.pid=manu_ 1 special.pid and within(d_start, d_end, s_start, s_end)=0 In the revised query, formulating the temporal portion of the query is simple. Namely, the revised query returns those rows that lack the WITHIN condition. Specifying that the query return a “0” or FALSE value produces rows that lack the WITHIN condition. FIGS. 3A and 3B are flow charts illustrating the steps performed by the present invention 124 in accordance with an embodiment of the single function operator system 124 . In particular FIG. 3A illustrates the steps performed by the present invention to create a WITHIN operator and FIG. 3B illustrates the steps performed by the present invention to create a SHARES operator. In FIG. 3A, block 300 represents the single function operator system 124 receiving a WITHIN operator. Block 302 represents the single function operator system 124 logically combining the EQUAL, DURING, STARTS, and FINISHES operators into a single function operation represented by the WITHIN operator. In FIG. 3B, block 304 represents the single function operator system receiving a SHARES operator. Block 306 represents the single function operator system 124 logically combining the OVERLAP, OVERLAPPED BY, DURING, CONTAINS, STARTS, STARTED BY, FINISHES, FINISHED BY, and EQUALS operators into a single operation represented by the SHARES operator. CONCLUSION This concludes the description of the preferred embodiment of the invention. The following describes some alternative embodiments for accomplishing the present invention. For example, any type of computer, such as a mainframe, minicomputer, or personal computer, or computer configuration, such as a timesharing mainframe, local area network, or standalone personal computer, could be used with the present invention. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.

A method, apparatus, and article of manufacture for detecting subsuming temporal relationships in a relational database. In accordance with the present invention, an invocation of a within operation that specifies a first event and a second event is received. In response to the invocation, a combination of temporal relationships between the first event and the second event is evaluated to determine (1) whether the second event starts at the same time as the first event or whether the second event starts before the first event and (2) whether the second event ends at the same time as the first event or whether the second event ends after the first event.

FIELD OF THE INVENTION This invention relates generally to the field of tying knots and more particularly securing, shortening and drawing objects together in the performance of a multitude of tasks using knots in the binding material. BACKGROUND OF THE INVENTION Using the prior art techniques, binding material in the form of lace, line, string, rope, cable, ribbon or any other kind of material in the furtherance of utility of drawing and binding items together such as clothing, etc. use binders having two free ends. This is true of the draw strings in sweatcloths, and all sorts of other clothes, as well as the laces of shoes. The field in which binders are used is manifold. However, the common problems of using binders with two free ends to draw the binding laces and draw points together and securing the laces together in the form of a knot are that the more secure the knot, the tighter the knot must be and the harder it is to untie when the need arises and conversely, if tied too loosely, the free ends allow the possibility of the knot being inadvertently loosened or untied. Articles of clothes use lace binders in all forms and the lace has two free ends. When a knot is tied in the two free ends the tighter you draw the free ends against the two draw points and add a very tight knot the harder it is to untie the same or alternatively, the looser the knot is tied, the easier it is for the knot to come undone. Moreover, since there are two free ends there is a greater likelihood that one or more of the free ends will recede through an eyelet at the draw point or draw points when the knot is untied causing further problems. If the binder material were not composed of two free ends, these problems would not occur. However, most of the knots used in the prior art would not be usable to serve as a method of first drawing the draw points together and then securely knotting the binder together for the purpose of securing, shortening, and drawing objects together, using a knot that will not be inadvertently untied, but that will be untied easily when so desired. SUMMARY OF THE INVENTION This invention has the advantage of using these principles in combination with a newly discovered knot creating technique which allows the user to form a secure knot while offering the option of undoing the knot swiftly and with minimal resistance and at the same time have the binder material between the two draw points be a continuous lace of material. Accordingly, it is a primary objective of the present invention to teach a new and improved method of securing, shortening, and drawing objects together using a knot. Another object of the present invention is to teach a new and improved method of securing, shortening, and drawing objects together with continuous lace of binding material using a new and improved knot. Another object of the present invention is to teach a new and improved method of securing, shortening, and drawing objects together with continuous lace of binding material using a new and improved knot containing one bow of two loops and an identifiable point at which the knot can be untied by the withdrawal of one or both loops of a bow through the center of the knot. Another object of this invention is to introduce a bow-knot in a continuous lace of binding material which will not be untied by pulling either or both of the two resultant bow loops. Another object of this invention is to introduce a bow-knot in a continuous lace of binding material whose loops, either together or separately, can be used as handles to carry the object secured. It might be noted here that the continuous lace of material used as the starting point to tying said knot can likewise be used for carrying objects in the starting continuous condition of being unknotted. Another object of this invention is to introduce a method of creating two apertures in a bow-knot by tying a new and improved knot in a continuous line of binding material by which objects could be suspended without the possibility of having those objects released by way of movement or weight releasing the knot. Another object of the present invention is to teach a new and improved method of tying a knot without utilizing loose ends of a strand of binding material so that the knot would avoid the hazards of the dangling "free" ends of material, with the resultant insecurity of the knot and eventual degradation of the ends of the binding material. Another objective of the teachings of the present invention is to offer an alternative knot wherever a conventional bow-knot would have been appropriate, such as tying shoestrings or securing the waist of a garment which is secured by tying an appropriate lace of material. Another objective of the teachings of the present invention is to allow manufacturers and eventual users of various items which could have been secured by using conventional knots from the possibility of inadvertently separating the lace material used to bind the draw part of the article of clothes from the article of clothes when manipulating the article of clothes. For example, the draw string will not disappear into the sweatpants waist. This is accomplished because the knot outlined herein allows for the manufacture of garments or footwear, etc., with a fastening binding material which is continuous and without loose ends, thereby eliminating the possibility that the fastening agent can be separated from the draw part of the article, such as the piece of clothing. BRIEF DESCRIPTION OF THE FIGURES These and other objectives, features and advantages of the present invention should become apparent from the following description when taken in conjunction with the accompanying drawings in which; FIG. 1 shows the continuous lace between two draw points which is the starting point for creating the new and improved knot of the present invention. FIG. 2 shows the continuous lace of FIG. 1, being rotated in its entirety for 180 degrees. Continue to move one portion of the oval formed by the portion of the material above the point at which the material crosses in the same direction until such portion can be folded down and through that space. FIGS. 3a & 3b show the effect of pulling the material as described above after releasing the cross point and holding the material so that two interim loops would be formed. After successfully beginning to pull the material through the space described above let the cross point loose and hold an opposite end of the material flowing through that space. The result is the creation of a half-knot close to the origin of the material and a free flowing lace of material which allows for the manipulation of the size of the two interim loops. FIG. 4 shows both interim loops extended with a sub-loop formed in one interim loop and with a section of the opposite interim loop encircling this sub-loop. The sub-loop must be created by using material closest to the draw point. FIG. 5 shows a section of the interim loop opposite the half-knot being pulled through that space created where the sub-loop is crossed by a section of the interim loop. FIG. 6 shows the resultant two sub-loops being pulled through the spaces created to form the two final loops of the bow-knot. FIGS. 7, 8 and 9 show the final knot at various stages of being tightened, with FIG. 9 indicating the section to pull to release the knot. DETAILED DESCRIPTION OF THE INVENTION The final product of this invention is a bow-knot following a half-knot. The qualities of this knot which are unique are the ability to release the knot in a quick and easy fashion and the ability to tie this knot in a closed loop lace of material such that said knot will not be untied by pulling either or both loops of the resultant bow-knot. To tie this knot the individual need only have a closed loop of material which could take the form of a continuous circle of material or a loop of material originating from two separate draw points. Continuous material as used herein means a lace, a line, a string, a rope, a cord, a cable, and all the alternatives forms of binding means which may be used to bring draw points together. The draw points may be the eyelets of shoes, corsets, or the draw string access holes for sweatpants, sweatshirts, dresses, trousers, sweaters, hoods of coats, hats, etc.. In some instances the lace, line, rope, cable, passes through the draw points into the sweatpants, dresses, trousers, hoods of coats, etc., in the form of a continuous line, binder, lace, string inside the article with respect to which the draw points are connected and sometimes the lace line rope string, etc., is attached to the article in the vicinity of the draw points. The important feature is that the draw points are connected by a continuous lace of material for securing, shortening and drawing objects and articles of clothing together. The teachings of the present invention relate to the new and improved knot and method for making the same described herein. Specifically, the teachings of the present invention relate to a lace of continuous material running between two draw points by drawing the continuous material tight between the two draw points. Reference is made to FIG. 1 where the draw points are shown as two eyelets such as would be found in a shoe, sweatpants, sweatshirt, etc. The teachings of the invention relate to drawing the two draw points together by creating a half-knot by the manipulation of the continuous lace as shown if FIGS. 2, 3a and 3b. The acme of the lace is shown by the darkened point which appears in each of the figures, but is defined by FIG. 1, as the mid point of the original loop. In one mode for tying the knot the left side of the loop is crossed over in front of (front being the side facing the tyer) the right side of the loop near the draw points and holding the laces together with the left hand where they cross over the upper part of the loop just above where it crosses the right side of the loop is (as shown if FIG. 2) taken over, behind, and brought forward under the right side of the loop between the cross over and the right draw point, forming (as shown in FIG. 3a) a half-knot between the two sides of the loop near the draw points and (as shown in FIG. 3b) with the remainder of the material in the continuous loop running out from each side of the half-knot and joined under the half-knot that has been drawn tight against the continuous material to form two loops one on each side of the halfknot, that are adjustable in length, slack in one loop being taken up by increasing the length of the other loop by sliding the continuous material under the half-knot, and drawing up said two loops in said half-knot tight so as to bring the two draw points together to the desired location and tension. Thereafter, to utilize the two loops to form a bow-knot (as shown in FIGS. 4,5,6,7,8,9), holding the part of each loop that comes off the half-knot, a bow-knot is tied between the two sides by using the part that comes off the half-knot as a standing end (as in the prior art of tying a bow-knot with two free ends of a lace of material) and then pulling each loop of the resultant bow until all the slack in the continuous material of the knot is taken up by the two loops. The loops of the bow-knot made in accordance of the teachings of the present invention are connected in such a way that if the proper part of the knot is pulled, i.e. that part of the bow-knot where the loops are joined by continuous material, the bow-knot and the half-knot are untied and the continuous lace of material returns to its original condition of being unknotted. The method identified in the proceeding paragraph could be labeled a right hand method of tying the new and improved knot according to the teachings of the present invention. However, if the word left is inserted for the word right in the paragraph above the method identified could be described as a left hand method of tying the new and improved knot according to the teachings of the present invention. The final product of this invention is a bow-knot following in a half-knot. The qualities of this knot which are unique are the ability to release the knot in a quick and easy fashion and the ability to tie this knot in a closed loop of material such that said knot will not be untied by pulling either or both loops of the resultant bow-knot. To tie this knot the individual need only have a closed loop of material which could take the form of a continuous circle of material or a loop of material originating from two separate draw points, as shown in FIG. 1. This loop is extended so that the material in which the knot will be created is taught, as shown in FIG. 1. Then rotate the original form of loop 180 degrees, as shown in FIG. 2. This motion forms a point at which the material crosses, preferably closer to the point of origin of the draw points. Then, if one visualizes this interim form of a loop as a four part figure, with the cross, referred to above, indicating the midpoint of the four sections, and they further being delineated by the two draw points and the acme of the figure, hold this form at the point at which these sections cross, grasp an upper portion of the form, and maneuver one portion of the upper section, as shown in FIG. 2, down and through the space formed between the draw points and the cross now being held by the person manipulating the material. Continue to pull the form in the way described herein until a half-knot with two loops is formed, as shown in FIG. 3a and 3b which loops are interim in form, said half-knot being stationary and temporarily securing the draw points. An identifying feature of this half-knot in continuous material is that the points of intersection between the interim loops which is furthest from the half-knot is free moving, and when each interim loop is manipulated in size so that they are equal or nearly so, on the face of the knot, the acme of the original loop is centered, said point eventually being the point at which the resultant bowknot will be untied. Then split one interim loop into two loops by pinching a section of material to form same, then fold the section of the unaltered interim loop nearest the half-knot around this pinched section of material. This will create a triangle of material consisting of those portions immediately originating from the half-knot. Reach through this section and pull that portion of the interim loop through this triangle that has a common connection to that portion of the continuous loop which is free-moving. Then continue to pull each of these "newly" formed loops until the material supporting them is exhausted. Pull until tight and the knot is complete. What is created is a half-knot held secure by a bow-knot. The knot can be released by pulling the section of the continuous material connecting the loops of the resultant bow, which will dominate the face of the knot. This section can be accentuated by coloring or the installation of a device attached to or encircling the continuous material, as a bead, which can act as an aid to untying the knot. Another method describing the teachings of the present invention includes describing as an improved method of securing, shortening, or drawing objects together with a continuous lace of material running between first and second draw points and tying a bow-knot with a knot tied using the following method: (a) using an unbroken lace of material from the first draw point to the second draw point to form a loop, as shown in FIG. 1; (b) rotating said loop for 180 degrees, as shown in FIG. 2, so that the two sides of the loop cross forming a smaller upper loop; (c) holding the point at which the cross is formed and continuing by drawing a point on a half-section of the upper loop down and through that portion of the original loop below the cross until two interim loops are formed by then holding the remaining half-section, as shown in FIG. 3a; (d) pulling the two interim loops to tighten the draw points until the acme of the original loop is brought up to but not under the half-knot and the resulting two interim loops are of equal size, and the desired level of tension applying force to the draw points is exerted by the half-knot, as shown in FIG. 3b; (e) the half-knot being formed by those two portions of the continuous lace of material which have their origin in closest proximity to the original draw points; (f) pinching the portion of one of the interim loops to form a sub-loop that is on the half-section thereof closest to the half-knot, as shown in FIG. 4; (g) holding said sub-loop and pulling the other interim loop so that a portion which is closest to the half-knot encircles the said sub-loop, as shown in FIG. 5; (h) pulling the portion of the opposite interim loop furthest from the half-knot through the hole formed by the two draw points and the point at which the material crosses; (i) pulling both sub-loops to tighten the knot forming a complete double-loop bow-knot, as shown in FIGS. 7 & 8. The improved method as described, teaches that the knot formed thereby is released and untied by pulling said continuous lace of material at approximately its original acme or the corresponding point on the adjacent directly connected portion of the continuous lace. The teachings of the present invention include many facets, including: (A) A method of tying a knot in lace of material that was originally a continuous strand of material with two draw points, so that a knot as described herein can be tied without having to make use of a loose end of material, said knot having the quality of being able to be tightened and held securely by action of a half-knot prior to being secured by creating a bow-knot. (B) A method of tying a knot with a string or other piece of material after having secured the two loose ends of a length of material, either by securing the material to a surface by mechanical or chemical means, so that the material is anchored to the surface, or by creating a physical impediment to the free movement of the material in the material itself so that a portion of the material is anchored to the surface, and tying said knot without the use of the original free ends of the material. (C) A method of tying a knot comprising a half-knot formed at the draw points in a given piece of material acting as the foundation for a bow-knot which said bow-knot acts both as the mechanism by which the original half knot is held taught and as the mechanism by which the knot can be untied. (D) A method of shortening, or removing the excess or slack from a continuous rope or other material by tying a knot consisting of a half-knot secured by a bow-knot. (E) A method of tying a secure knot in a closed loop of material, said knot being adjustable and able to be untied in a fashion that does not require a release of pressure upon that portion of the knot drawing portions of a body together or binding portions of a body together. (F) A method of tying a secure knot in a closed loop of material in which said knot will not be untied by pulling apart the draw points of the object. (G) A method of securing, shortening or drawing objects together with a draw string or lace which can not be lost in object such as clothing beyond the draw points because the draw string is continuous and unbroken. (H) The method of tying a knot as taught herein is particularly enhanced by the fact that one can put a marker such as coloring or tag of any color or form at the mid point of the original loop of continuous material or a device of any form that encircles the lace of continuous material between the two draw points, as a marker to help adjust the size of the loops in the course of tying the knot as taught herein and at the same time to identify the point on the continuous material where the knot can be pulled so as to release and untie the knot with ease. (I) The method of tying a knot as taught herein is enhanced by the fact that the final bow loops can be pulled out either singly or at the same time and may in fact be used as apertures for holding items associated with the task of securing, shortening and drawing objects together. (J) The method of tying a knot as taught herein is enhanced by the fact that there are no loose ends of a strand of material that can become frayed or provide the hazards and insecurity of dangling free. (K) The method of tying a knot as taught herein is enhanced by the fact that the continuous lace or draw string of material can never be lost by being pulled through an aperture or draw point. The foregoing description has been directed to particular embodiments of the invention in accordance with the requirements of the Patent Statutes for the purposes of illustration and explanation. It will be apparent, however, to those skilled in this art that many modifications and changes will be possible without departure from the scope and spirit of the invention. It is intended that the following claims be interpreted to embrace all such modifications.

A method of binding material with a knot including: drawing a continuous lace of binding material around the material to be bound so that two separate draw points are formed, tying the continuous lace of material initially in a half-knot with two equal subloops for bringing the two draw points together, additionally tying a double-loop bow-knot in the continuous lace of material wherein the midpoint of the continuous lace of material is located substantially in the center portion of the knot and the acme of each box loop is comprised substantially of the first and third quarter points of the original continuous loop.

This application is a continuation of U.S. patent application Ser. No. 10/281,787, filed Oct. 28, 2002, which issued as U.S. Pat. No. 6,616,142 which is a continuation of application Ser. No. 09/994,245 filed on Nov. 26, 2001, which issued as U.S. Pat. No. 6,494,454 which is a continuation of U.S. patent application Ser. No. 09/664,257, filed on Sep. 18, 2000, which issued as U.S. Pat. No. 6,322,078, which is a continuation of U.S. patent application Ser. No. 08/838,178, filed on Apr. 16, 1997, which issued as U.S. Pat. No. 6,120,031, which is a continuation of U.S. patent application Ser. No. 08/500,532, filed on Jul. 11, 1995, which was abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 08/311,781, filed on Sep. 23, 1994, which issued as U.S. Pat. No. 5,431,408. The present invention is directed to games and, more particularly, to novel games which provide a player with the opportunity to reserve a “wild” indicia from one play for use in a subsequent play. BACKGROUND OF THE INVENTION Games utilizing playing cards are popular throughout the world. Many people get hours of enjoyment and relaxation from playing cards. In certain parts of the world, wagering adds an additional dimension of excitement to the game. Whether in “card room” games where the players play against each other or in a traditional “casino” game environment where an employee of the house acts as a banker, wagering adds excitement to many forms of card games. Players involved in card games with wagering often enjoy new games with relatively simple rules that can readily be learned by a beginner or casual player. Typical card games involve a dealer providing a plurality of cards to each player. Each player then gathers the cards and tries to form the best possible hand according to some predetermined hierarchy of hand values. For example, a standard poker hierarchy is, in descending order, Royal Flush, Straight Flush, Four of a Kind, Full House, Flush, Straight, Three of a Kind, Two Pair, One Pair, and High Card. In some games, players are permitted to discard certain cards and receive new cards in an effort to form a better hand. It is also common to designate one or more cards as “wild” cards which can have any one of a predetermined number of values at the option of the player(s) receiving such wild cards. In this manner, the designation of wild cards within a deck can significantly increase the chances of a player attaining a particular hand. In known games which utilize wild cards, players must use the wild card in the hand in which the wild card is received. Therefore, if a player has a card hand of low or no value, the wild card may not be sufficient to allow that player to form a winning hand. For example, if the payout schedule for a given game starts at a pair of jacks, and the player has the following hand: 2, 4, 5, 10 of different suits and a wild card, the best poker hand that the player could form with one wild card would be a pair of 10's. This hand would not qualify for a winning payout. It is, therefore, desirable to provide a card game which increases the player's excitement and enjoyment, as well as the level of player participation by providing a player with an opportunity to maximize the impact of receiving a wild card. It is also desirable to provide wagering games other than cards with an exciting, new feature which comprises a wild indicia and novel methods of using that wild indicia. It is also desirable to provide novel games readily adaptable to wagering which are relatively simple to learn for new players. It is also desirable to provide games which provide one or more players with opportunities to modify the player's winning payout by using such a wild indicia, received during one play, with a subsequent play. SUMMARY OF THE INVENTION The various embodiments of the present invention are directed to games which provide a player who has received at least one wild indicia during one play with the opportunity to reserve that wild indicia for use in a subsequent play. The advantages of the present invention are applicable to a wide variety of games including “card” games and other conventional games of chance or skill including keno, bingo, gaming devices, such as reel slots, dice games and lotto. As used herein, the term “card game” is intended to include conventional table/board type games wherein one or more persons deal actual playing cards to one or more players, as well as any type of mechanical or electronic devices which display indicia of playing cards. According to an aspect of the invention, a gaming device is provided that includes a display screen that is capable of generating video images, and the gaming device is programmed to select a first group of indicia from a plurality of indicia in a first game, wherein the plurality of indicia include a plurality of playing indicia and at least one wild indicia. The gaming device is also programmed to cause a video image representing the first game to be displayed on the display screen, to provide a player with a winning advantage if the player receives the at least one wild indicia, and to limit the use of the at least one wild indicia. According to another aspect of the invention, a gaming device is provided that includes a display screen that is capable of generating video images, a plurality of selection devices, and a value input device. The gaming device is programmed to determine that a player has used the value input device to make a wager, provide a first group of playing indicia to define a first game, the first group of playing indicia being selected from a plurality of playing indicia, and provide at least one wild indicia for use in other than the first game. The gaming device is also programmed to cause a video image representing the first game to be displayed on the display screen, determine that the player has used one of the plurality of selection devices to reserve the at least one wild indicia for use in a subsequent game, determine a first game outcome associated with the first group of playing indicia, and determine a first payout according to a payout schedule, the first payout being associated with the first game outcome. The gaming device is further programmed to provide a subsequent group of playing indicia to define the subsequent game, the subsequent group of playing indicia being selected from the plurality of playing indicia, determine that the player has used at least one of the plurality of selection devices to combine the at least one wild indicia with the subsequent group of playing indicia to define a modified group of playing indicia, determine a game outcome associated with the modified group of playing indicia, and determine a subsequent payout associated with the game outcome associated with the modified group of playing indicia by modifying the payout for the game outcome associated with the modified group of playing indicia. According to a third aspect of the invention, a gaming device is provided that includes a display screen that is capable of generating video images, a value input device, and a plurality of selection devices. The gaming device is programmed to select a first group of indicia from a plurality of indicia in a first game, the plurality of indicia including a plurality of playing indicia and a wild indicia, wherein the wild indicia is not one of the plurality of playing indicia, and provide a player with the option of reserving the wild indicia in the first game for use in a subsequent game. The wild indicia of the present invention may take any form desired by the players or the establishment conducting the game. For example, when playing a card game, the wild indicia will typically comprise a wild card. While jokers maybe utilized to indicate a wild card, it is also within the scope of the present invention to use one or more other indicia such as one of the other cards of a deck or non-conventional indicia to indicate a wild card. Similarly, in games other than card games, any form of wild indicia may be utilized. In all forms of the present invention, a player is provided with the possibility of utilizing a wild indicia when it is most advantageous for the player to do so, i.e., when the player will maximize a winning payout. When a player receives a wild indicia, the player can use that wild indicia immediately or may reserve the wild indicia for use in a subsequent play. For example, a player may use a wild card in a subsequent hand or may use a wild indicia received during the play of one game of bingo in a subsequent game. One preferred embodiment of the present invention comprises a gaming device having an electronic touch-sensitive screen which is controlled, at least in part, by a player touching images on the screen. Another embodiment of the present invention comprises a gaming device wherein input from a player is supplied to a device through actuation buttons. A still further embodiment of the present invention comprises a game table designed for use by a dealer and a plurality of players. Along with conventional indicia on the game table including betting areas for each player, each player area is also provided with a reserve area wherein a player may place a wild card if that player decides not to use the wild card in the hand in which he receives the wild card and prefers to use the wild card in a later hand. Each of the embodiments of the present invention provides one or more players with opportunities to maximize the beneficial effect of a wild indicia. These and other embodiments are described in greater detail with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a gaming device embodiment of the present invention comprising a touch screen. FIG. 2 illustrates a touch screen used with the embodiment of FIG. 1 . FIG. 3 illustrates a gaming device of another embodiment of the present invention. FIG. 4 illustrates a board game embodiment of the present invention. DETAILED DESCRIPTION The various embodiments of the present invention increase the level of player input, increase the likelihood of a winning payout, provide at least one player with the possibility to maximize the amount of a winning payout, and increase the overall level of enjoyment to a game which utilizes at least one wild indicia. The present invention achieves these desirable results by providing a player who receives a wild indicia during the play of one game with the option of reserving that wild indicia for use in a subsequent game. While the various embodiments of the present invention are illustrated in conjunction with a game of five-card draw poker, the advantages of the present invention are equally applicable to a wide variety of other games of skill or chance. According to the illustrated embodiments, five indicia of playing cards are displayed to a player. The player is provided with the opportunity to discard one or more of the cards and, if the player has received a wild card, to place that wild card in a reserve area for use with a later hand. To the extent that the player has discarded any cards or moved a wild card from his hand to a reserve area, the player is provided with replacement cards. Furthermore, a player may be provided with the option of reserving a wild card even if that player received the wild card as a draw card, i,e., as a replacement to one of the first indicia of playing cards displayed to that player. A winning payout is then provided to either the player with the highest hand or to any players which have attained a winning hand as determined by a predetermined payout schedule. According to one preferred embodiment of the present invention, a first plurality of playing card indicia which is displayed to a player is selected from a collection which does not include a wild card. In this manner, the game can be controlled so that the first plurality of card indicia displayed to a player never contains a wild card. The cards remaining after making the first display can then be reshuffled along with one or more wild cards to form a second collection of cards from which additional cards are selected. The first plurality of playing card indicia may comprise a number of cards sufficient to form a complete hand or some lower number of cards. For example, the first three cards displayed to a player in a five-card poker hand may be selected from the first collection, which does not include any wild cards, while all remaining cards may be selected from collections to which at least one wild card indicia has been added. Similarly, wild card indicia may be placed in a first collection of cards from which the player's first card indicia are selected and then wild card indicia not displayed to one or more players as of a certain point in a hand may be removed so that no further wild cards are displayed. For example, in a five-card draw poker game, each player's first five cards may be selected from a first collection comprising one or more wild cards while draw cards may be selected from a second collection from which wild cards have been removed. From the present description, those skilled in the art will appreciate that the odds of a player attaining a successful hand may be modified by modifying certain parameters of a game including the number of wild cards used, the number of indicia displayed from collections comprising one or more wild indicia, and the timing of when indicia are selected from collections comprising wild indicia. These and other parameters may be modified without departing from the scope of the present invention. Further limitations can be placed upon one or more of the games of the present invention by limiting the number of plays for which a player may reserve a wild indicia. For example, in a game of bingo, a player may be provided with the opportunity of reserving a wild indicia for ten bingo games. In such instances, if the player does not use the reserved wild indicia within ten games after the wild indicia was displayed, the wild indicia would be forfeited. Similarly, in a card game, a player may be limited to utilizing a wild indicia in a certain number of hands following receipt of that wild indicia. By so limiting the use of a wild indicia, a player's chances of achieving a very high payout can be controlled. Those skilled in the art will also appreciate that the chances of displaying a wild indicia to a player can be controlled by controlling the total number of playing indicia in the collection from which cards are selected, by controlling the number of wild indicia added to the collection, as well as by keeping the wild indicia out of the collection until a predetermined number of indicia have been displayed. FIG. 1 illustrates one embodiment of the present invention in the form of a gaming device 10 having a pressure-sensitive touch screen 20 , a coin slot 60 , a bill validator 70 , a credit card receiver/terminal 75 , flashing light 80 , payout schedule 85 , coin chute 90 and coin trough 95 . This embodiment of the present invention can be activated by a player inserting an item of monetary value including coins, paper currency, tokens, or some form of credit indicator, such as a credit card. Suitable instructions are provided in instruction window 22 to guide a player through the initial steps necessary to start the game, as well as through subsequent steps. If a player has inserted more than the amount of the minimum wager, the player will be required to designate the amount of his wager by touching the corresponding wager area 24 under the designation “SELECT WAGER.” The amount wagered will then be displayed in wager window 26 . If the player has inserted an amount greater than the amount wagered, the player's remaining credits will appear in the credits window 28 . Wagers for subsequent hands can then be automatically drawn from the player's credits in a manner which is now well known in the art. After a player has selected an amount for an initial wager, a plurality of indicia of playing cards 30 is displayed on the screen. Following instructions and prompts provided in instruction window 22 , the player may opt to hold one or more of the cards by simply touching the image of the card on screen 20 . An actuator may also be provided for this and other player input on a button panel. If the player receives a wild card, the player may also opt to reserve the wild card for use in a subsequent hand by touching the “RESERVE WILD CARD” area 32 . When a player reserves a wild card, the player is preferably provided with an image of the wild card in reserved area 34 . In this and other embodiments of the present invention, a player may or may not be permitted to utilize a wild indicia in the same hand or game in which the player designated that the wild indicia be reserved. Such rules are preferably set by the house or other rulemaker prior to play. Furthermore, as stated above, a player may receive a wild indicia either in an initial display or in a subsequent display, such as cards drawn after a discard. If the player has discarded any cards and/or reserved a wild card, replacement cards are provided to the player's hand and displayed in card display area 30 . If the resulting display comprises one of a predetermined plurality of winning card hands, the player is provided with a winning payout. Particularly high winning payouts may be accompanied by discernable signals such as a flashing light 80 and audible sirens from a speaker (not shown). The amount that the player has won is then preferably added to the amount shown in the “CREDITS” window 28 . As an example, the hand shown in card display area 30 of FIG. 2 indicates a hand in which a player would want to utilize a wild card previously held in RESERVED area 34 . Those familiar with poker will appreciate that by replacing the 3 of diamonds with the wild card, the player will have attained a Royal Flush and, typically, a large payout. Since the present invention can be played with a wide variety of games, the winning payouts for a winning hand can vary widely. As an example, with the five-card draw poker game described above, the payout schedule could be as follows: SAMPLE TABLE PAYOUT SCHEDULE Royal Flush 800 for 1 Straight Flush  50 for 1 Four Of A Kind  25 for 1 Full House  8 for 1 Flush  5 for 1 Straight  4 for 1 Three Of A Kind  3 for 1 Two Pair  2 for 1 Pair of Jacks or better  1 for 1 An alternative embodiment of the present invention is illustrated in FIG. 3 in the form of a gaming device. This embodiment of the present invention differs from the embodiment illustrated in FIGS. 1 and 2 in that decisions are input to the machine by the player depressing one or more buttons on a button panel 125 . Button panel 125 comprises a “DEAL/DRAW” button 126 , “BET ONE” button 128 , a “BET MAX” button 127 , a plurality of “HOLD” buttons 132 , a “RESERVE WILD CARD” button 133 , a “CASH/CREDIT” button 136 , a change button 137 and a “COLLECT WINNINGS” button 138 . According to this embodiment of the present invention, after a player has input monetary value into coin slot 160 or bill validator 170 , he can select the amount that he wants to wager on the present hand by depressing “BET ONE” button 128 the number of times needed to properly show his wager in the wager window on screen 120 or BET MAX button 127 . The remaining portion of the player's credits will be indicated in credit window 129 . The player then depresses “DEAL/DRAW” button 126 in order to receive a first plurality of cards. The player may then select which cards to hold by depressing corresponding “HOLD” buttons 132 , which are most preferably aligned with the indicia of playing cards 130 appearing on screen 120 . If the player has received a wild card that he wishes to reserve for use in a subsequent hand, the player then depresses “RESERVE” button 133 , which will move the wild card up into wild card reserve area 134 on screen 120 . When the player has made his selection regarding which cards to hold and/or reserve, he must then again press “DEAL/DRAW” button 126 in order to receive replacement cards. According to this illustrated embodiment, after the player has received any necessary replacement cards, the gaming device 100 automatically evaluates whether the player has received a winning hand and, if he has, provides a winning payout according to payout schedule 185 , signals the winning payout with flashing light 180 and increases the player's credits shown in credit window 129 accordingly. When a player has finished playing and wishes to withdraw any credits shown in credit window 129 , the player can simply depress “COLLECT WINNINGS” button 138 in order to receive his money from coin chute 190 and coin trough 195 and/or credits. As illustrated, button panel 125 is also provided with “CHANGE” button 137 which will alert a casino attendant that a player requires change. Another embodiment of the present invention is illustrated in FIG. 4 wherein a gaming table 200 is provided with a playing surface 210 , chip rack 220 , card shoe 230 and discard tray 240 . A plurality of player stations is located around the playing surface. According to this embodiment of the present invention, each playing area comprises a wager area 250 , a card area 260 and a wild card reserve area 270 . According to this embodiment of the present invention, when a player wishes to reserve a wild card for subsequent use, the reserved wild card is placed in a “wild card reserve area” 270 . While the present embodiments have been described as providing a player with an option of reserving a wild card when that player receives such a wild card during the initial deal, the various embodiments of the present invention can also provide a player with the option of reserving a wild card for use in a subsequent hand even if that player receives one or more wild cards as replacement cards for those which he had originally discarded or reserved. Furthermore, a player may be provided with the option of retrieving a wild indicia from a wild indicia reserve area for use in the same game that the wild indicia was received, either between or after the player has received or seen additional playing indicia. As a further enhancement to the excitement provided by the games of the present invention, it is also within the scope of the present invention to provide a higher or lower payout when the player uses a wild indicia. The present invention is readily adapted for use with a wide variety of wagering games of chance or skill including blackjack, other forms of poker, keno, bingo, lotto, as well as with video slots and/or a reel slot. For example, other card games such as blackjack may be similarly played wherein one or more wild card indicia are displayed to players either in a physical form, such as in a table version, or as an image on a screen in a video version. Those skilled in the art will appreciate that the present invention can be modified for use in other games with or without additional restrictions. For example, in a bingo game, a wild indicia received during one game may be utilized in subsequent games to cover whatever spot that a player chooses. In a lotto game, a player might utilize a wild indicia for use as any number in a subsequent play. Still further embodiments may comprise placing a wild indicia on one or more faces of a die for use in a dice game. Therefore, it is within the scope of the present invention to utilize the traveling wild indicia of the present invention in games of craps. In a keno game, the keno game could be limited to permit a player to use a reserved wild indicia in subsequent plays only if the player was using an identical wager in an identically played game. The use of the wild indicia may be restricted to a predetermined number of hands following the receipt of the wild indicia by the player. These and other restrictions may or may not be imposed on other wagering games of chance or skill. According to further embodiments of the present invention, a wild indicia may have limitations. For example, the wild indicia may be completely wild in that it can be used as a substitute to any indicia in the game. Alternatively, the wild indicia may be restricted so that it can only be played as certain other symbols. Furthermore, according to a further embodiment of the present invention, the mere reciept of a wild indicia can provide a player with one or more winning advantages. For example, a wild indicia may act as a multiplier in order to modify the payout schedule. Alternatively, the receipt of a wild indicia may provide or qualify the player for a super-jackpot. Still futhermore, a player may be provided with an opportunity to increase the amount of a payout by some percentage, e.g., 25% or even by a multiplier of two or three. Still furthermore, the wild indicia could also provide opportunities for a player to qualify for other opportunities. For example, in a card game if a wild card was utilized to form a royal flush, that winning player could be entered into a super-jackpot prize drawing. Those skilled in the art will appreciate that these embodiments may be achieved without departing from the scope of the present invention.

A gaming device is provided that includes a display screen that is capable of generating video images, the gaming device being programmed to select a first group of indicia from a plurality of indicia in a first game, wherein the plurality of indicia include a plurality of playing indicia and at least one wild indicia. The gaming device also being programmed to cause a video image representing the first game to be displayed on the display screen, to provide a player with a winning advantage if the player receives the at least one wild indicia, and to limit the use of the at least one wild indicia.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to information processing technologies. In particular, the invention relates to a method of processing information in which a plurality of pieces of input data are processed individually and output in parallel, a method of displaying moving image thumbnails, and a decoding apparatus and an information processing apparatus to which the methods are applied. [0003] 2. Description of the Related Art [0004] With the remarkable progress of information processing technologies in recent years, information processing apparatuses that perform high-speed operations have become readily available. Likewise, technologies for processing various types of data, including images and sound, has been developed. As a result, it has been possible for users to easily acquire various types of data for reproduction and processing as desired. [0005] Given these circumstances, technologies for processing a plurality of pieces of data of a sort in parallel and outputting the same in parallel have come into common use for the purpose of grasping the contents of vast amounts of data, comparing the results of processing, and the like. The wide spectrum of applications of such technologies includes, for example, displaying thumbnails of compression-coded moving image files in a moving image reproducing apparatus, and comparing images for the sake of image analysis on a plurality of pieces of data, such as images, sound, or temperatures, all pieces of data being acquired from multiple channels in real time. [0006] In order for such data processing systems to achieve parallel processing, it is necessary to create threads in accordance with the number of pieces of data to process, and divide limited resources such as CPUs and memories temporally and spatially to allocate them to the individual threads. Consequently, a greater number of threads can increase the system load when an attempt is made to increase the number of thumbnails able to be displayed at a time or when an attempt is made to increase the number of input channels allowing for the comparison of more results. It has thus been difficult to increase the number of pieces of data to be output in parallel if predetermined output rates must be ensured when performing a high level of real-time processing in parallel, such as when displaying moving image thumbnails by simply reproducing a plurality of moving images as thumbnails, and when comparing time variations of a plurality of channels of data. SUMMARY OF THE INVENTION [0007] The present invention has been developed in view of the foregoing problem, and a general purpose thereof is to provide a technology for outputting a large number of pieces of data smoothly in parallel. [0008] One embodiment of the present invention relates to a method of processing information. This method of processing information includes: creating threads for respective input data streams, and switching the same for processing, the threads each being for applying predetermined processing to an input data stream and storing the resulting intermediate data in a corresponding buffer; and reading a plurality of pieces of the intermediate data from the respective corresponding buffers to output a plurality of pieces of output data in parallel. The switching for processing includes: detecting the amount of the intermediate data that is stored and yet to be read in the buffers when starting to process the threads; and stopping processing of a thread when the amount of the intermediate data thereof exceeds a predetermined value, and switching processing to other threads. [0009] Here, the “input data streams” may be data to be output continuously for certain periods of time, or streams of time-series data which are determined to be processed and output within certain allowable ranges of time. They may be any of data of compression-coded moving image files, audio files, and the like, and combinations of these, as well as various types of uncompressed data and the like. The “predetermined processing” may therefore be determined by the types of the input data streams and desired output data, and may include a plurality of processing units regardless of whether they are the same or of different types. For example, the “predetermined processing” may be decoding in the case of compression-coded data, or in the cases of other data, image analysis, audio analysis, two-dimensional profile creation, and the like. The output data may be obtained by applying necessary processing to the intermediate data. The intermediate data may simply be output. [0010] The “threads” typically refer to processing units which exercise certain subdivided functions of processes corresponding to applications. As employed herein, however, they shall also refer to processes themselves or processing units that correspond to components to be called to exercise certain functions, as long as they correspond to some units of processing or functions. [0011] Another embodiment of the present invention relates to a method of displaying moving image thumbnails. This method of displaying moving image thumbnails includes: creating decoding threads and drawing threads for respective compression-coded moving image files, and switching the same for processing, the decoding threads each being for decoding a moving image file and storing generated texture data in a corresponding texture buffer, the drawing threads each being for reading the texture data from the corresponding texture buffer and generating and storing image frame data in a corresponding frame buffer; and reading the image frame data on the plurality of moving image files from the respective corresponding frame buffers, and outputting the same to a display device in parallel. The switching for processing includes: detecting the amount of the texture data that is stored and yet to be read in the texture buffers when starting to process the decoding threads; and stopping decoding-related processing of the decoding thread when the amount of the texture data thereof exceeds a predetermined value, and switching processing to other threads. [0012] Yet another embodiment of the present invention relates to a decoding apparatus. This decoding apparatus includes: an input unit which inputs coded data streams; a decoding unit which switches the plurality of data streams input to the input unit and decodes the same in succession; a plurality of buffers which are provided corresponding to the respective data streams, and temporarily store intermediate data decoded by the decoding unit; and an output unit which reads the plurality of pieces of intermediate data stored in the plurality of buffers to output a plurality of output data in parallel. Before decoding a data stream, the decoding unit detects the amount of the intermediate data that is stored and yet to be read in the corresponding buffer, and stops decoding of the data stream and starts other processing if the amount of the intermediate data exceeds a predetermined value. [0013] Yet another aspect of the present invention relates to an information processing apparatus. This information processing apparatus includes: a plurality of buffers corresponding to a plurality of compression-coded moving image files, respectively; a processor unit which creates decoding threads and drawing threads for the respective moving image files, and switches the same for processing, the decoding threads each being for decoding a moving image file and storing generated texture data in a corresponding buffer, the drawing threads each being for reading the texture data from the buffer and generating image frame data corresponding to the moving image file; and an image display unit which displays the image frame data on the plurality of moving image files, generated by the processor unit, in parallel. When starting to process a decoding thread, the processor unit determines whether or not to continue decoding-related processing of the decoding thread depending on the amount of the texture data that is stored and yet to be read in the buffer. [0014] It should be appreciated that any combinations of the aforementioned components, and any conversions of expressions of the present invention from/into methods, apparatuses, systems, computer programs, and the like may also be intended to constitute applicable embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0015] Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which: [0016] FIG. 1 is a diagram showing the configuration of an information processing apparatus according to an embodiment; [0017] FIG. 2 is a diagram showing the configuration of the processing unit when displaying a moving image thumbnail according to the present embodiment; [0018] FIG. 3 is a diagram schematically showing how threads are switched in the processing unit according to the present embodiment; [0019] FIG. 4 is a diagram for explaining the states of texture data stored in two texture buffers according to the present embodiment; and [0020] FIG. 5 is a flowchart showing a procedure in a processing time allocated for a decoding thread according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION [0021] FIG. 1 shows the configuration of an information processing apparatus according to the present embodiment. The information processing apparatus 100 includes a processor unit 20 , a memory 70 , an input device 75 , a storage device 80 , and a display device 90 . The processor unit 20 exercises centralized control over the entire apparatus; and performs such processing as decoding of compression-coded moving image files. The memory 70 stores running programs and data necessary for execution. The input device 75 accepts input instructions from a user. The storage device 80 stores moving image files. The display device 90 displays the frames of decoded moving image files. The processor unit 20 , the memory 70 , the input device 75 , the storage device 80 , and the display device 90 perform mutual data transmission via a bus 95 . [0022] The input device 75 may be any one of various input devices that are commonly used, such as a keyboard, a mouse, or a trackball. The storage device 80 may be a hard disk or a reader of a DVD (Digital Versatile Disk), a CD (Compact Disk) or other recording media which contain coded moving image files. [0023] The processor unit 20 includes a management unit 30 which controls processing of the information processing apparatus 100 , and a processing unit 40 which performs processing under the management of the management unit 30 . The management unit 30 controls the data input/output of the processor unit 20 from/into the memory 70 , the input device 75 , the storage device 80 , and the display device 90 . It also schedules processing in the processing unit 40 , and exercises control so that a plurality of processes or threads is switched for processing. [0024] The storage device 80 contains a plurality of compression-coded moving image files, which is stored in the memory 70 under the control of the management unit 30 when the input device 75 receives a user instruction to display moving image thumbnails. The processing unit 40 decodes the plurality of moving image files stored in the memory 70 in parallel, and generates image frame data to be output finally with respect to each of the moving image files. The management unit 30 then exercises control so that the generated image frame data is successively output to areas provided for the respective moving image files on the screen of the display device 90 . As a result, a plurality of moving image thumbnails appears on the display device 90 . [0025] The compression coding may be based on any one of the typical compression coding methods such as MPEG4, H.264/AVC, and SVC (Scalable Video Coding). [0026] In the present embodiment, the decoding processing for displaying the moving image thumbnail of one moving image file is performed by one thread. [0027] To display the moving image thumbnails of a plurality of moving image files, the processing unit 40 therefore runs a plurality of threads for decoding the plurality of moving image files in parallel. Moreover, the processing unit 40 also runs threads for generating image frame data based on the decoded data in parallel with running processes or threads other than those used for displaying moving image thumbnails. The processing unit 40 may be composed of a plurality of sub processors. Even in this instance, the management unit 30 allocates time-sharing threads to respective sub processors, thereby controlling the plurality of threads for parallel processing. [0028] This information processing apparatus 100 runs an operating system (hereinafter, abbreviated as OS) which provides functions and environment for making effective use of the information processing apparatus 100 , and exercises centralized control over the entire apparatus. A plurality of pieces of application software (hereinafter, referred to simply as applications) is run on the OS. For example, the management unit 30 can perform thread scheduling by simply utilizing the OS which is implemented in typical multithread-capable apparatuses. [0029] FIG. 2 shows components intended for displaying a moving image thumbnail in the processing unit 40 and the memory 70 . In FIG. 2 and in the processor unit 20 and the like shown in FIG. 1 , the individual elements shown as functional blocks for performing various types of processing can be constituted by a CPU, a memory, and other LSIs in terms of hardware. In terms of software, they can be achieved by programs and the like that have image processing functions. It will thus be understood by those skilled in the art that these functional blocks may be made up of various forms, including hardware alone, software alone, or any combinations of these, but not limited to any one of them. [0030] Among the blocks of the processing unit 40 shown in FIG. 2 , those enclosed by the broken line represent functional blocks for processing a decoding thread 43 , which is a thread for decoding one moving image file. As described above, according to the present embodiment, the thread for performing decoding processing is created for each moving image file. In fact, there is a plurality of decoding threads that have the same configuration as that of the decoding thread 43 , and the individual threads exercise their functions in respective time slices allocated by the OS. A drawing unit 50 also creates a drawing thread 51 for each moving image file, so that image frame data is generated on different moving image files in respective time slices. [0031] The processing unit 40 , as mentioned previously, can also process threads other than the threads shown in FIG. 2 , i.e., those threads used for displaying moving image thumbnails. In this case, the processing unit 40 exercises other functions in some time slices. Such functional blocks will be omitted from the diagram, however, since their functions are not particularly limited in the present embodiment. [0032] The memory 70 includes a file storing unit 47 , a texture buffer 48 , and a frame buffer 52 . The file storing unit 47 contains compression-coded moving image files. The texture buffer 48 stores texture data on each frame. The frame buffer 52 stores image frame data to be displayed on the display device 90 . The texture buffer 48 and the frame buffer 52 may be formed in reserved areas of an additional graphic memory (not shown). The texture buffer 48 and the frame buffer 52 are allocated to individual moving image files. The decoding threads 43 and the drawing threads 51 use the individual areas in the texture buffer 48 and the frame buffer 52 , which are allocated to the respective corresponding moving image files. In the following description, the individual areas in the texture buffer 48 and the frame buffer 52 will also be referred to as the texture buffer 48 and the frame buffer 52 . [0033] The processing unit 40 includes an initial processing unit 42 , a decoding unit 44 , and a buffer write unit 46 which serve as a decoding thread 43 for a moving image file. The initial processing unit 42 acquires a compression-coded moving image file from the file storing unit 47 of the memory 70 . The decoding unit 44 decodes the coded moving image file. The buffer write unit 46 stores the decoded data in the texture buffer 48 as texture data. The processing unit 40 also includes a drawing unit 50 which serves as a drawing thread 51 . The drawing unit 50 reads texture data from the texture buffer 48 , generates image frame data, and writes it to the frame buffer 52 . [0034] As will be described later, the initial processing unit 42 also makes a determination on whether or not to continue subsequent processing, based on the number of frames of texture data stored in the texture buffer 48 . The buffer write unit 46 may apply necessary processing such as RGB conversion to the data decoded by the decoding unit 44 when rendering it into texture data. The drawing unit 50 performs necessary processing such as texture mapping to polygons depending on the type of the moving image file, thereby generating image frame data. The drawing unit 50 may read data necessary for generating the image frame data, excluding the texture data, from the memory 70 when needed. [0035] A description will now be given of operations for achieving the present embodiment using the aforementioned configurations. In the present embodiment, the decoding threads 43 in the processing unit 40 modify their own processing times to increase the efficiency of processing for displaying a plurality of moving image thumbnails. For the sake of demonstrating the effect of the present embodiment, a description will first be given of the case where time slices allocated by a typical OS are used without modification. [0036] FIG. 3 schematically shows an example of thread switching in the processing unit 40 . [0037] The horizontal direction of the diagram corresponds to the time axis. A first decoding thread 43 a , a first drawing thread 51 a , a second decoding thread 43 b , a second drawing thread 51 b , and another thread 55 , or a thread other than for displaying a moving image thumbnail, are processed in respective time slices in succession. In reality, the order of processing may vary with priority-based scheduling by the OS. For example, the first decoding thread 43 a may be followed by the thread 55 . [0038] When the allocated processing times end, the threads free their CPU allocations and enter an execution queue to stand by until the next processing time arrives. The decoding threads 43 and the drawing threads 51 are not limited to two, or to the first and second threads each, but are created for as many as the number of moving image files to be thumbnailed. It should be appreciated that all the threads repeat processing even after the times shown in the figure. [0039] The buffer write unit 46 of the first decoding thread 43 a stores texture data on a moving image in a first texture buffer 48 a , or in an area allocated in the texture buffer 48 , frame by frame. While the first decoding thread 43 enters the queue, the first drawing thread 51 a starts processing. The drawing unit 50 consumes the texture data in the first texture buffer 48 a frame by frame to generate image frame data on that moving image, and stores it in a first frame buffer 52 a , or in an area allocated in the frame buffer 52 . These processes are repeated to display the moving image thumbnail of one moving image file on the display device 90 . [0040] Similarly, the second decoding thread 43 b stores texture data in a second texture buffer 48 b , and the second drawing thread 51 b consumes it to store image frame data in a second frame buffer 52 b . The moving image thumbnail of another moving image file is thus displayed on the display device 90 . [0041] If not all the texture data stored in the texture buffers 48 can be consumed by the respective drawing threads 51 in a single processing time, the remaining texture data is simply left in the texture buffers 48 . Then, the buffer write units 46 of the respective decoding threads 43 store the newly-generated texture data in the texture buffers 48 as well. [0042] When storing texture data in the texture buffers 48 , the buffer write units 46 activate counters (not shown) for counting the numbers of frames of the texture data stored in the texture buffers 48 . If the processing unit 40 is processing a decoding thread 43 in one time slice and the buffer write unit 46 detects from the corresponding counter that the texture buffer 48 is full or is becoming full, then the decoding thread 43 frees its CPU allocation and enters the execution queue, even during the time slice. As will be described later, in the present embodiment, the counters are also consulted by the initial processing units 42 . [0043] The rates at which the decoding units 44 decode moving image files vary depending on the original images. Take, for example, moving image files that are predictive-coded using differential images between actual images and images predicted from reference frames. Then, the amount of operations varies between scenes that are almost motionless and scenes that contain quick motions or significant color changes. The decoding rates are higher in the former cases. The decoding rate can also vary from one scene to another even in a single moving image file. Moreover, if a plurality of moving image files is reproduced simultaneously like when displaying moving image thumbnails, the moving image files have different decoding rates at the same point in time. [0044] FIG. 4 schematically shows the states of texture data stored in two texture buffers, or the first texture buffer 48 a and the second texture buffer 48 b , to be used by the decoding threads for two moving image files of different decoding rates, or the first decoding thread 43 a and the second decoding thread 43 b , at one point in time. In this instance, the first decoding thread 43 a shall decode a moving image file that has a higher decoding rate, and the second decoding thread 43 b shall decode a moving image file that has a lower decoding rate. [0045] In the shown example, the first texture buffer 48 a and the second texture buffer 48 b allocated for the respective threads are capable of storing eight frames of texture data each. Here, the rectangles represent a single frame each. The symbol “o” shown in the single-frame rectangles indicates the number of frames of texture data that are stored and yet to be consumed in the texture buffers 48 . In the shown example, the first texture buffer 48 a contains seven frames of texture data, and the second texture buffer 48 b contains one frame of texture data. [0046] In general, the OS allocates processing times to respective threads uniformly. Therefore, the first decoding thread 43 a having a higher decoding rate can process more frames than the second decoding thread 43 b does in one processing time. Furthermore, it is more likely for the first decoding thread 43 a to fill up the allocated first texture buffer 48 a and free its CPU allocation before the completion of the time slice. In the environment where a plurality of sub processors processes a plurality of threads in parallel, the first decoding thread 43 a therefore enters the queue more frequently than the second decoding thread 43 b does. Even in this case, the OS gives the same priority to the first decoding thread 43 a and the second decoding thread 43 b since the two are the same threads for “decoding a moving image file.” As a result, the number of times the first decoding thread 43 a is processed becomes greater than the number of times the second decoding thread 43 b is processed. [0047] For the foregoing reasons, as shown in FIG. 4 , the first texture buffer 48 a allocated for the first decoding thread 43 a consistently comes to store a larger amount of texture data than the second texture buffer 48 b allocated for the second decoding thread 43 b does. Furthermore, under such circumstances, only a small amount of texture data on the moving image file corresponding to the second decoding thread 43 b can be accumulated. It may thus sometimes be impossible to generate a sufficient number of pieces of image frame data even when the corresponding second drawing thread 51 b starts processing. This increases the possibility that the image frame data fails to meet the output timing of the display device 90 and the moving image thumbnail drops frames. [0048] To prevent moving image thumbnails from dropping frames, the OS may be operated to assign priorities dynamically upon scheduling, such as by giving higher priorities to decoding threads of moving image files that have low decoding rates. Nevertheless, this can sometimes lower the priorities of other processes that do not pertain to displaying moving image thumbnails relatively. Since it is undesirable that other essential processes be unstable in priority, the present embodiment incorporates the priorities and schedules provided by typical OSes without change while achieving a reduction in the number of moving image thumbnail frames dropped. [0049] As mentioned above, the decoding thread having a higher decoding rate and the decoding thread having a lower decoding rate cause a difference in the amount of texture data accumulated in the texture buffers 48 . The present embodiment utilizes this difference to give priority to the decoding thread of a lower decoding rate among the group of “decoding threads” for processing. Furthermore, the priorities are adjusted in real time since the decoding rates vary from one scene to another. [0050] Specifically, a first threshold F 1 and a second threshold F 2 (where F 1 <F 2 ) are provided for the amount of texture data to be stored in each texture buffer 48 . In this instance, the second threshold F 2 has the same capacity, or comparable capacity, as that allocated for the texture buffer 48 . Then, if once the amount of texture data stored exceeds the second threshold F 2 , yield processing is performed until the amount of texture data stored falls to or below the first threshold F 1 . In the yield processing, decoding is skipped to free CPU allocation and processing is passed (hereinafter, referred to as yielded) to the next thread. When the texture data is consumed by a drawing unit 50 and the amount of texture data stored falls to or below the first threshold F 1 , the decoding processing is resumed and continued until the stored amount exceeds the second threshold F 2 again. [0051] FIG. 5 shows the procedure in the processing time allocated for a decoding thread 43 according to the present embodiment. Initially, the time allocated by the OS for the decoding thread 43 starts (S 10 ). The initial processing unit 42 checks a flag value which is stored in a register or the like (not shown) (S 12 ). The flag value is “0” when the decoding thread 43 is in its initial state, such as immediately after the function for displaying a moving image thumbnail is activated by a user. If the flag value is “0” (Y at S 12 ), the initial processing unit 42 acquires a moving image file to be decoded from the memory 70 (S 20 ). Then, the decoding unit 44 and the buffer write unit 46 perform decoding and writing to the texture buffer 48 as normal (S 22 ). [0052] When writing texture data, the buffer write unit 46 consults the counter to check if the number of frames of texture data stored in the texture buffer 48 reaches the second threshold F 2 (S 24 ). If the stored amount is smaller than the second threshold F 2 (Y at S 24 ), the decoding processing is continued until the time allocated for this thread is completed (N at S 28 , S 22 ). If the amount of texture data stored reaches the second threshold F 2 (N at S 24 ), the flag value is set to “1” (S 26 ). Under the control of the OS, processing such as saving register values to the memory 70 is performed to end the thread processing (S 30 ). Step S 30 is also performed when the allocated time is completed before the amount of texture data stored reaches the second threshold F 2 (Y at S 28 ). [0053] If the flag value is “1” at the beginning of processing of the decoding thread 43 (N at S 12 ), the initial processing unit 42 detects the number of frames of texture data stored in the texture buffer 48 by using the counter which is managed by the buffer write unit 46 . Then, the initial processing unit 42 checks if the number of frames stored is greater than the first threshold F 1 (S 14 ). [0054] The first threshold F 1 is determined as appropriate by calculation or by experiment based on such factors as the coding method of the moving image file to be decoded and the required frame rate. For example, in the texture buffers 48 shown in FIG. 4 , a first threshold F 1 is set to two frames with respect to a memory capacity of eight frames. In the example of FIG. 4 , assuming the first threshold F 1 is two frames, the first texture buffer 48 a contains texture data having a greater number of frames than the threshold, and the second texture buffer 48 b contains texture data having a smaller number of frames than the threshold. [0055] If the amount of texture data stored is greater than the first threshold F 1 (Y at S 14 ), yielding is performed since the amount of texture data accumulated is sufficient to generate image frame data. In this instance, ordinary OS-based thread switching is performed, accompanied by such processing as saving the register values to the memory 70 (S 18 ). This processing may actually be performed by the OS calling its own functions. [0056] If the amount of texture data stored is smaller than or equal to the first threshold F 1 (N at S 14 ), the initial processing unit 42 sets the flag value to “0” (S 16 ). Then, the foregoing steps S 20 to S 30 are performed to accumulate texture data. [0057] Using the foregoing procedure, the decoding threads 43 in turn can yield by themselves to reduce consumption of the processing times when processing moving image files or certain scenes of higher decoding rates. The suppression increases the numbers of times other threads are processed, and by extension the number of times other decoding threads of lower decoding rates are processed per unit time which translates into higher priorities of the other decoding threads. In this instance, the priorities determined by the OS are still unchanged. The priorities of the threads for decoding the moving image files are therefore unaffected relative to the other threads, and unstable factors such as delayed operation of other processes will not occur. [0058] Consider that in some instances some moving image files or scenes require a long time to decode, that is, only a small number of frames of texture data can be generated therefrom in one processing time. Since the number of times the threads for decoding such files or scenes are processed per unit time is increased, it is possible to increase the amount of texture data to be stored in the texture buffers 48 . Meanwhile, decoding threads with higher decoding rates perform yielding so that only their texture data is consumed, and the amount of data stored in the texture buffers 48 decreases once. The threads resume storing texture data when the amount of data stored is reached the first threshold F 1 , or the minimum limit of not running short. [0059] Then, the decoding threads with higher decoding rates continue their decoding processing until the stored amount of data reaches the second threshold F 2 . Since decoding threads that come to yield once have a sufficient amount of texture data accumulated, they can perform yielding continuously to yield a large block of time to other threads even when their allocated time arrives. The decoding threads with lower decoding rates can thus utilize the yielded time for efficient decoding processing. [0060] In consequence, a sufficient amount of texture data for the drawing units 50 to generate image frame data is stored in any of the texture buffers 48 that are allocated for the decoding threads 43 . It is therefore possible to reduce the number of moving image thumbnails frames dropped. [0061] The present embodiment was applied to an actual case of displaying 25 moving image thumbnails. When OS-based processing time control was exercised alone without the application of the present embodiment, a total of 20 to 30 dropped frames per second was observed from the 25 moving images. In contrast, the application of the present embodiment could suppress dropped frames to a level of several frames per second in total. At such a level, it is extremely unlikely that users would notice the dropped frames visually. [0062] According to the present embodiment described above, when displaying a plurality of moving image thumbnails, threads for displaying moving images with higher decoding rates and threads for displaying moving images with lower decoding rates are determined by detecting the amount of texture data stored in the texture buffers in real time. Then, the decoding threads with higher decoding rates quit their decoding processing and yield even when their OS-based processing times are started. The yielding is performed without running short of texture data. Consequently, it is possible to make effective use of the processing time to increase the number of times the threads for decoding moving images with lower decoding rates are processed per unit time, and therefore reduce the number of dropped frames ascribable to insufficient accumulation of texture data. [0063] The present embodiment can provide an increase in the processing speed for displaying moving image thumbnails substantially through software improvements. This improvement can thus be implemented at a lower cost when compared to cases where the processing speed is improved through improvements to hardware such as a CPU or a bus. Moreover, since the OS has to only undertake ordinary operations, the present embodiment can be applied to various types of apparatuses used for general purposes, ranging from mobile terminals to large-scale systems. [0064] Up to this point, the present invention has been described in conjunction with the aforementioned embodiment thereof. The foregoing embodiment has been given solely by way of illustration. It will be understood by those skilled in the art that various modifications may be made to combinations of the foregoing components and processes, and all such modifications are also intended to fall within the scope of the present invention. [0065] For example, the present embodiment has dealt with the case where the threshold for the amount of buffering for the decoding threads to yield is determined in advance. Alternatively, the threshold may be determined automatically in an adaptive fashion while displaying moving image thumbnails, depending on such factors as the coding methods of the moving image files and the display device. [0066] The present embodiment has also dealt with the case where the processing times are transferred between a plurality of decoding threads which is created to display a plurality of moving image thumbnails. The same processing can also be applied to any processes as long as they create a plurality of threads each of which generates output to respective buffers allocated thereto and threads which consume data stored in the respective buffers. Examples of the possible applications include: multiple input and output devices which perform rendering, sound processing, and the like and output each of a plurality of pieces of real-time data that are input from an external device such as a camera, a microphone, or a temperature sensor; and processing for making a plurality of outputs based on a plurality of pieces of data that are acquired from a plurality of network computers. [0067] For apparatuses that perform such processing, the present embodiment is particularly effective in instances where it is difficult to change the priorities of respective threads determined by the OS, such as when additional processes are in operation. [0068] The present embodiment has dealt with the procedure intended for multithreads of the preemptive type in which the OS allocates the same processing times to the respective threads. Alternatively, the present embodiment may also be applied to multithreads of the non-preemptive type in which the threads free their CPU allocations to switch thread processing at predetermined processing timing. Even in this case, different decoding rates result in different numbers of times for threads to enter the execution queue. Therefore, the numbers of times decoding threads with lower decoding rates perform processing can be increased by yielding of decoding threads with higher decoding rates. As a result, it is possible to provide the same effects as those of the present embodiment. In this instance, the processing for checking the completion of allocated time at S 28 of FIG. 5 may be replaced with processing for checking if some process is performed at the switching timing. Alternatively, the timing when the amount of texture data stored reaches F 2 , or N at S 24 , may be used as the switching timing.

A method of processing information, includes: creating threads for respective input data streams, and switching them for processing, the threads each being for applying predetermined processing to an input data stream and storing the resulting intermediate data into a buffer; and reading multiple pieces of the intermediate data from the respective corresponding buffers to output multiple pieces of output data in parallel. The switching for processing includes: detecting the amount of intermediate data that is stored and yet to be read in the buffers when starting processing the threads; and stopping processing of the thread when the amount of the intermediate data thereof exceeds a set value, and switching processing to other threads.

PRIORITY CLAIM This application is a divisional of and is based on non-provisional application Ser. No. 09/397,566 which was filed in the U.S. Patent and Trademark Office Sep. 16, 1999 now U.S. Pat. No. 6,306,839 and provisional application No. 60/100,601 which was filed in the U.S. Patent and Trademark Office on Sep. 16, 1998. BACKGROUND OF THE INVENTION The present invention provides novel 2-methoxyimino-2-(pyridinyloxymethyl)phenyl acetamide compounds with (derivatised) hydroxyalkyl substituents on the pyridine ring, their use as fungicidal compounds, and their use in fungicidal compositions comprising at least one of the 2-methoxyimino-2-(pyridinyloxymethyl)phenyl acetamide compounds as the active ingredient. SUMMARY OF THE INVENTION This invention provides novel 2-methoxyimino-2-(pyridinyloxymethyl)phenyl acetamide compounds of Formula (1), below wherein m is an integer 0-3; L is —O—, —CH 2 —, —SO n —, —CH 2 O—, —OCH 2 —, —CH 2 S—, —SCH 2 —, —CH═CH—, —C≡C—, or  wherein n is an integer 0-2; X, Y, and Z are each independently H, C 1-6 alkyl, C 1-6 alkoxy, halo-C 1-6 alkyl, halo-C 1-6 alkoxy, halo, nitro, carbo-C 1-6 alkoxy, cyano, C 1-6 alkylthio, or halo-C 1-6 alkylthio; W is H, halogen, C 1-4 alkyl, C 1-4 alkoxy, halo-C 1-4 alkyl, or C 1-4 alkylthio; R 1 is H, C 1-6 alkyl, cycloalkyl, haloalkyl, alkoxyalkyl, alkenyl, alkynyl, haloalkenyl, haloalkynyl, trialkylsilyl, phenyl (optionally substituted by C 1-4 alkyl, halo, alkoxy, haloalkyl, or haloalkoxy), benzyl (optionally substituted by C 1-4 alkyl, halo, methoxy, haloalkyl, or haloalkoxy), alkylsulphonyl, optionally substituted benzenesulphonyl, trialkylphosphonyl, optionally substituted saturated or unsaturated 5 or 6 membered heterocycle, or —CO—R 4 ; R 2 is H, alkyl (optionally, a C 1-6 alkyl), cycloalkyl, phenyl (optionally substituted by C 1-4 alkyl, halo, alkoxy, haloalkyl, haloalkoxy, alkoxycarbonyl, alkylcarbonyl, arylcarbonyl, or aryloxy), hydroxyalkyl, optionally substituted heterocycle, haloalkyl, optionally substituted naphthyl, or —CH 2 OR 5 ; R 3 is H, alkyl (optionally, a C 1-6 alkyl), cycloalkyl, phenyl (optionally substituted by C 1-4 alkyl, halo, alkoxy, haloalkyl, haloalkoxy, alkoxycarbonyl, alkylcarbonyl, arylcarbonyl, or aryloxy), hydroxyalkyl, optionally substituted heterocycle, haloalkyl, optionally substituted naphthyl or —CH 2 OR 5 ; or R 1 and R 2 together form a link of 1-3 atoms which form an optionally substituted heterocyclic ring containing one or more oxygen atoms; or R 2 and R 3 together form an optionally substituted carbocyclic or heterocyclic ring; R 4 is H, C 1-6 alkyl, cycloalkyl, haloalkyl, alkoxyalkyl, alkenyl, alkynyl, haloalkenyl, haloalkynyl, phenyl (optionally substituted by C 1-4 alkyl, halo, methoxy, haloalkyl, haloalkoxy), benzyl (optionally substituted by C 1-4 alkyl, halo, methoxy, haloalkyl, or haloalkoxy), alkoxy, or dialkylamino; and R 5 is alkyl (optionally, a C 1 -C 6 alkyl), alkanoyl, optionally substituted benzoyl, alkylsulphonyl, or optionally substituted benzenesulphonyl. The present invention also provides compositions comprising one or more compounds of Formula (1) in combination with phytologically-acceptable carriers and/or diluents. Methods for the use of compounds of Formula (1) and compositions comprising one or more compounds of Formula (1) are also provided. DETAILED DESCRIPTION OF THE INVENTION Throughout this document, all temperatures are given in degrees Celsius and all percentages are weight percentages, unless otherwise stated. The term “halogen” or “halo” refers to F, Cl, I, or Br. The term “alkyl”, “alkenyl”, or “alkynyl” refers to a straight chain or branched chain carbon radical containing the designated number of carbon atoms. The term “alkoxy” refers to a straight or branched, chain alkoxy group. The term “halo alkyl” refers to a straight or branched alkyl group substituted with one or more halo atoms. The term “halo alkoxy” refers to an alkoxy group substituted with one or more halo atoms. The term “aryl” or “Ph” refers to a phenyl group. The term “substituted aryl” refers to a phenyl group substituted with C 1 -C 6 alkyl, C 1 -C 6 alkoxy, halo-C 1 -C 6 alkyl, halo-C 1 -C 6 alkoxy, halo, nitro, carbo-C 1 -C 6 alkoxy, or cyano. The term “heteroaryl” refers to pyridyl, pyridinyl, pyrazinyl or pyridazinyl. The term “Me” refers to a methyl group. The term “Et” refers to an ethyl group. The term “Pr” refers to a propyl group. The term “Bu” refers to a butyl group. The term “EtOAc” refers to ethyl acetate. The term “ppm” refers to parts per million. The term, “psi” refers to pounds per square inch. The term “M.P.” refers to melting point. The term “bp” refers to boiling point. While all the compounds of this invention have fungicidal activity, certain classes of compounds may be preferred for reasons such as, for example, greater efficacy or ease of synthesis. A preferred class includes those compounds of Formula (2), below wherein the substituents are as defined in Formula (1), above. A more preferred class includes those compounds of Formula (3), below wherein the substituents are as defined in Formula (1), above. A next more preferred class includes those compounds of Formula (4), below wherein the substituents are as defined in Formula (1), above. A next more preferred class includes those compounds of Formula (5), below wherein the substituents are as defined in Formula (1), above. A next more preferred class includes those compounds of Formula (6), below wherein X is methyl, halo, or haloalkyl and the additional substituents are as defined in Formula (1), above. Currently, it is sometimes preferred when R 1 is hydrogen, C 1-4 alkyl, formyl, alkanoyl, alkoxycarbonyl, dialkylaminocarbonyl, or dialkylphosphonyl and R 5 is H, C 1-4 alkyl. Compounds of the present invention may be prepared by routes commonly known in the art using commercially available or readily synthesized starting materials. Such general procedures are described in Scheme 1 and Scheme 2, below, wherein the substituents are as described in Formula (1), above, and V is a leaving group, such as, for example, F, Cl, or So 2 CH 3 . An compound of Formula (8) is reacted with an appropriately substituted pyridine derivative of Formula (7) in the presence of a base in an aprotic solvent. Examples of an appropriate solvent for this reaction would include, but are not restricted to, tetrahydrofuran, dimethyl sulphoxide, acetone, acetonitrile, dimethyl formamide, or N-methylpyrrolidinone. Examples of an appropriate base for this reaction would include, but are not restricted to, sodium hydride, potassium hydride, potassium carbonate, potassium t-butoxide, or a tertiary amine derivative such as triethylamine. A ketone derivative of Formula (9) is reacted with an organometallic reagent of the form R 3 -M in a compatible solvent to give an alcohol of the Formula (10). Examples of a group R 3 -M would include, but are not restricted to,a Grignard reagent such as methyl magnesium bromide, an organolithium reagent such as phenyl lithium or a hydride transfer reagent such as sodium borohydride. Examples of a suitable solvent would be tetrahydrofuran, diethyl ether, or an appropriate alcohol, selected by compatibility with the reagent and the transformation being carried out. The compound of Formula (10) may be further derivatised by reaction with an appropriate alkylating or acylating reagent R 1 -Q, optionally in the presence of an appropriate base. Compounds of the Formula R 1 -Q would include, but are not restricted to acetic anhydride, benzyl bromide, dimethyl carbamoyl chloride, ethyl chloroformate, diethyl phosphoryl chloride, 5-chloro-3-methyl-2-methylsulphonylpyridine. Examples of a suitable base would include, but are not restricted to a tertiary amine such as triethylamine or pyridine, sodium carbonate, sodium hydride, potassium hydride, or potassium t-butoxide. A compound of Formula (10) may also be reacted with a sulphonyl chloride of the formula RSO 2 Cl) in the presence of a suitable base in a compatible solvent to give the corresponding chloride of Formula (11). Examples of a suitable sulphonyl chloride would be methanesulphonyl chloride, p-toluenesulphonyl chloride, and examples of a suitable base would be pyridine, triethylamine, or Hünig's base. The compound of formula (11) may be reacted further with a metal alkoxide salt in a compatible solvent to give a compound of Formula (1). Examples of a suitable metal alkoxide would include sodium methoxide, potassium ethoxide, or magnesium methoxide produced in situ by the addition of magnesium metal to methanol. The following examples further illustrate this invention. The examples should not be construed as limiting the invention in any manner. EXAMPLE 1 5-Acetyl-3-chloro-2-methylthiopyridine 5-Acetyl-2,3-dichloropyridine (24.5 g, 0.129 mol) was slurried in t-butanol (200 mL) and sodium methanethiolate (10 g, 0.143 mol) was added. The mixture was heated under reflux conditions for two hours, cooled to room temperature, and diluted with water (200 mL) and ether (150 mL). This was separated and the aqueous phase extracted with ether (50 mL). The combined organic extracts were washed with water (100 mL) and saturated sodium chloride solution (100 mL), dried over anhydrous sodium sulphate, and evaporated to dryness to give the desired product (24.1 g, 94%) as a pale, low melting solid. EXAMPLE 2 3-Chloro-5-(1-hydroxyethyl)-2-methylthiopyridine 5-Acetyl-3-chloro-2-methylthiopyridine (24.1 g, 0.12 mol) was slurried in absolute ethanol (200 mL) and sodium borohydride (4.5 g, 0.118 mol) added in portions. The reaction mixture was stirred at room temperature for 48 hours and acidified to pH 2 with 2N hydrochloric acid. This was then diluted with water (200 mL) and the bulk of the ethanol evaporated under reduced pressure, the temperature of the mixture being maintained below 50° C. The reaction mixture was diluted with water (200 mL) and extracted twice with dichloromethane (15 mL). The combined organic extracts were washed with water (200 mL) and saturated sodium chloride solution (100 mL), dried over anhydrous sodium sulphate, and evaporated to dryness to give the desired product (21.9 g, 90%) as an orange oil. EXAMPLE 3 5-(1-Benzyloxyethyl)-3-chloro-2-methylthiopyridine 3-Chloro-5-(1-hydroxyethyl)-2-methylthiopyridine (21.9 g, 0.108 mol) was dissolved with stirring in anhydrous DMF (250 mL) and 60% sodium hydride (5 g, 0.125 mol) added in portions. The mixture was stirred at room temperature for 30 minutes and benzyl bromide (17.6 g, 0.103 mol) added dropwise. The mixture was then stirred at room temperature for four hours, diluted with water (400 mL) and extracted three times with ethyl acetate (100 mL). The combined organic extracts were washed twice with water (200 mL) and saturated sodium chloride solution (100 mL), dried over anhydrous sodium sulphate, and evaporated to dryness. Purification of the residue by chromatography over silica (0-5% ethyl acetate:hexane) gave the desired product (25.0 g, 79%) as a pale yellow oil. EXAMPLE 4 5-(1-Benzyloxyethyl)-3-chloro-2-methylsulphonylpyridine 5-(1-Benzyloxyethyl)-3-chloro-2-methylthiopyridine (25 g, 0.085 mol) was dissolved with stirring in dichloromethane (600 mL) and 60% m-chloroperoxybenzoic acid (53.8 g, 0.19 mol) added in portions. The reaction mixture was stirred at room temperature overnight and 10% sodium carbonate solution (300 mL) added. The reaction mixture was stirred at room temperature for one hour, separated, and the organic phase washed four times with 2N sodium hydroxide solution (150 mL). It was then washed with saturated sodium chloride solution (150 mL), dried over anhydrous sodium sulphate, and evaporated under reduced pressure to give the product (26.5 g, 96%) as a clear viscous oil. EXAMPLE 5 Benzeneacetamide, 2-[[[5-(1-benzyloxyethyl)-3-chloro-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 60% Sodium hydride (0.8 g, 0.2 mol) was washed twice with 50 mL portions of hexane and slurried in anhydrous THF (40 mL). 2-(Hydroxymethyl)-α-(methoxyimino)-N-methyl-benzeneacetamide (2.0 g, 0.009 mol) was then added in one portion and the mixture stirred at room temperature for 30 minutes. A solution of 5-(1-benzyloxyethyl)-3-chloro-2-methylsulphonylpyridine (3.0 g, 0.009 mol) in anhydrous THF (5 mL) was added and the mixture stirred at room temperature overnight. Water (100 mL) was added and the mixture extracted three times with ethyl acetate (50 mL). The combined organic extracts were washed twice with water (100 mL) and then with saturated sodium chloride solution (50 mL). The solvent was evaporated under reduced pressure and the residue purified by chromatography over silica (30% ethyl acetate:hexane) to give the desired product (2.8 g, 66%) as a clear viscous gum. EXAMPLE 6 Benzeneacetamide, 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- Sodium borohydride (129 mg; 3.4 mmol) was added in one portion to a solution of 2-[[[5-benzoyl-3-chloro-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (1.0 g; 2.3 mmol) in ethanol (23 mL) and dichloromethane (3 mL). The reaction was stirred for 10 minutes and quenched with 1N hydrochloric acid (2 mL). The reaction mixture was extracted twice with dichloromethane (20 mL), and the combined organic layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated to give the desired product (993 mg; 99%) as a white foam. EXAMPLE 7 Benzeneacetamide, 2-[[[5-[(acetyloxy)phenylmethyl]-3-chloro-2-pryridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- Acetic anhydride (0.17 mL; 1.8 mmol; 2 eq) was added dropwise at 0° C. to a solution of 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (400 mg; 0.91 mmol) and 4-dimethylaminopyridine (167 mg; 1.4 mmol; 1.5. eq) in dichloromethane (5 mL). The reaction mixture was warmed slowly to room temperature, and stirring continued for 10 minutes. The reaction mixture was quenched with water, partitioned, and the aqueous phase was extracted twice with dichloromethane. The combined organic layers were washed with 1N hydrochloric acid followed by saturated sodium chloride solution, then dried over anhydrous sodium sulphate, filtered and concentrated. Purification of the crude residue by flash chromatography using 50% EtOAc in hexanes provided the acetate as a sticky white foam (395 mg; 0.84 mmol; 93%). EXAMPLE 8 Benzeneacetamide, 2-[[[3-chloro-5-[[(trifluoroacetyl)oxy]phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- A solution of 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (515 mg; 1.2 mmol) and pyridine (0.38 mL; 4.7 mmol; 4 eq) in dichloromethane (5 mL) was cooled to 0° C. for the dropwise addition of trifluoroacetic anhydride (0.33 mL; 2.3 mmol.; 2 eq). The reaction was warmed slowly to room temperature and was quenched with water. Upon partitioning, the aqueous layer was extracted twice with dichloromethane (5 mL), and the combined aqueous layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. The crude product was placed under vacuum to remove the last traces of pyridine. The desired product (68 mg; 0.13 mmol; 11%) was isolated by chromatography over neutral alumina (50% ethyl acetate:hexane). EXAMPLE 9 Benzeneacetamide, 2-[[[3-chloro-5-[[[(dimethylamino)carbonyl]oxy]phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (500 mg; 1.1 mmol) and 4-dimethylaminopyridine (836 mg; 6.8 mmol; 6 eq) were dissolved in dichloromethane (5 mL), and dimethylcarbamoyl chloride (0.31 mL; 3.4 mmol; 3 eq) was added at room temperature. The reaction mixture was heated to reflux for three hours, cooled back down to room temperature and quenched with water. The aqueous layer was extracted twice with dichloromethane (5 mL), and the combined organic layers were washed with 1N hydrochloric acid and saturated sodium chloride solution. They were then dried over anhydrous sodium sulphate, filtered and concentrated. The crude residue was purified by chromatography using 20% CH 3 CN and dichloromethane to yield the desired product (192 mg 34%). EXAMPLE 10 Benzeneacetamide, 2-[[[3-chloro-5-[(formyloxy)phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (200 mg; 0.45 mmol), triethylamine (0.31 mL; 2.3 mmol; 5 eq) and 4-dimethylaminopyridine (44 mg; 0.36 mmol; 0.8 eq) were dissolved in dichloromethane (3.6 mL), and the resulting solution was cooled to −40° C. Acetyl formyl anhydride (0.19 mL; 1.2 mmol; 2.5 eq) was added dropwise to the reaction mixture, and stirring was continued at low temperature until the reaction was complete after 10 minutes. The cooling bath was removed, and saturated sodium bicarbonate was added to quench any excess reagent still present. The aqueous phase was extracted with dichloromethane (2×3 mL), and the combined organic layers were washed with 1N hydrochloric acid followed by saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. The crude product was purified by chromatography using 50% EtOAc in hexanes to give the product (541 mg, 100%) as a white foam. EXAMPLE 11 Benzeneacetamide, 2-[[[3-chloro-5-[(diethylphosphonyl))phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- A solution of triethylphosphite (94 μL; 0.55 mmol; 1.2 eq) in dichloromethane (0.5 mL) was cooled to 0° C. for the addition of iodine (126 mg; 0.50 mmol; 1.1 eq). Stirring continued until the purple color dissipated, indicating complete formation of the phosphoryl iodide. This cold solution was transferred dropwise via cannula to a solution of 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (200 mg; 0.45 mmol) in pyridine (0.15 mL; 1.8 eq; 4 eq) and dichloromethane (4 mL). The alcohol solution turned yellow as the phosphoryl iodide reagent was added, but the color quickly dissipated as stirring continued. Upon completion of the addition, the reaction stirred at room temperature for another 30 minutes, turning brown in the process. It was quenched with saturated sodium bicarbonate solution and shaken with a crystal of sodium hydrogen sulphate. The aqueous phase was extracted with dichloromethane (2×3 mL), and the combined organic layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. The crude product was purified by chromatography using 70-80% EtOAc in hexanes to yield the desired product (130 mg, 50%) as a yellow-tinged foam. EXAMPLE 12 Benzeneacetamide, 2-[[[3-chloro-5-[[(tetrahydro-2H-pyran-2-yl)oxy]phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- Dihydropyran (0.16 mL; 1.7 mmol; 1.5 eq) and a catalytic amount of pyridinium p-toluenesulphonate (28 mg; 0.11 mmol; 0.1 eq) were added to a solution of 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (500 mg; 1.1 mmol) in dichloromethane (8 mL). The reaction was stirred at room temperature overnight and was quenched with half-saturated sodium chloride solution (5 mL). The aqueous layer was extracted twice with diethyl ether (5 mL), and the combined organic layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. Purification of the crude product by chromatography using 50% EtOAc in hexanes gave the desired product (521 mg, 87%) as a white foam. EXAMPLE 13 Benzeneacetamide, 2-[[[3-chloro-5-[[(triethylsilyl)oxy]phenylmethyl]-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-hydroxyphenylmethyl-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (500 mg; 1.1 mmol) and pyridine (0.18 mL; 2.3 mmol; 2 eq) were dissolved in dichloromethane (5.7 mL) at room temperature. The resulting solution was cooled to −20° C. for the dropwise addition of triethylsilyl triflate (0.39 mL; 1.7 mmol; 1.5 eq). The bath was removed, and the reaction mixture was warmed slowly to room temperature where it stirred for 30 minutes. It was quenched with water (10 mL) and diluted with diethyl ether (10 mL). The aqueous phase was extracted with diethyl ether (5 mL), and the combined organic layers were washed with 1N hydrochloric acid followed by saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. The crude product was filtered through a plug of silica gel using diethyl ether to afford the desired product (511 mg, 81%) as a sticky, colorless oil. EXAMPLE 14 Benzeneacetamide, 2-[[[3-chloro-5-(1-hydroxy-1-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- To a solution of 2-[[[5-benzoyl-3-chloro-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (1.0 g; 2.3 mmol) in THF (30 mL) was added a 3.0 M solution of methylmagnesium bromide in diethyl ether (4.6 mL; 13.7 mmol; 6 eq) at 0° C. The solution yellowed, and a precipitate appeared after a few minutes. The solution was warmed to room temperature where it was stirred for two hours. It was then cooled back down to 0° C. and quenched with aqueous ammonium chloride (20 mL). The aqueous layer was extracted twice with diethyl ether (10 mL), and the combined organic layers were washed with brine, dried over sodium sulfate and concentrated. The crude residue was passed through a plug of silica gel with the aid of diethyl ether to give the desired product (933 mg, 90%). EXAMPLE 15 Benzeneacetamide, 2-[[[3-chloro-5-(1-phenylethenyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-(1-hydroxy-1-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (933 mg; 2.1 mmol) was dissolved in CH 2 Cl 2 (10 mL), and triethylamine (0.87 mL; 6.2 mmol; 3 eq) was added at room temperature followed by methanesulfonyl chloride (0.40 mL; 5.2 mmol; 2.5 eq). The reaction mixture stirred for 30 minutes and was quenched with water. The aqueous layer was extracted twice with diethyl ether (20 mL), and the combined organic layers were washed with 1N HCl followed by brine and then dried over sodium sulfate and concentrated. The crude product was purified by flash column chromatography using 80% diethyl ether in hexanes to give the desired product (778 mg, 87%). EXAMPLE 16 Benzeneacetamide, 2-[[[3-chloro-5-(1,2-dihydroxy-1-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- A 60% solution of N-methylmorpholine N-oxide in water (1.9 mL; 11.0 mmol; 1.5 eq) was added to a solution of 2-[[[3-chloro-5-(1-phenylethenyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (3.2 g; 7.3 mmol) in aqueous acetone (30 mL acetone; 6 mL water) at room temperature. This was followed by the dropwise addition of a 4% solution of osmium tetroxide in water (1.43 mL; 0.18 mmol; 0.025 eq). The resulting reaction mixture stirred overnight, at which point sodium sulfite (250 mg) was added to quench any remaining oxidants. Stirring was continued until a black precipitate appeared, and the solution was diluted with water (15 mL) and extracted twice with EtOAc (30 mL). The combined organic layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. Purification by chromatography using a step gradient of 50-80% EtOAc in hexanes yielded the desired product as a brownish foam (3.5 g, 100%). EXAMPLE 17 Benzeneacetamide, 2-[[[3-chloro-5-(2-hydroxy-1-[[(4-methylphenyl)sulfonyl]oxy]-2-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-(1,2-dihydroxy-1-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (1.22 g; 2.6 mmol) was dissolved in pyridine (6 mL) and the solution was cooled to 0° C. for the addition of p-toluenesulphonyl chloride (743 mg; 3.9 mmol; 1.5 eq). The bath was removed, and the reaction mixture stirred at room temperature overnight. It was then quenched with water (6 mL) and diluted with EtOAc (10 mL). The aqueous layer was extracted with EtOAc (6 mL), and the combined organic layers were washed with 1N hydrochloric acid followed by saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. The crude tosylate was purified by chromatography using 50% EtOAc in hexanes to afford 1.3 g (2.0 mmol; 80%) of the pure product as a white solid (M.P. 55-60° C.). EXAMPLE 18 Benzeneacetamide, 2-[[[3-chloro-5-(2-phenyloxiranyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl- 2-[[[3-chloro-5-(2-hydroxy-1-[[(4-methylphenyl)sulfonyl]oxy]-2-phenylethyl)-2-pyridinyl]oxy]methyl]-α-(methoxyimino)-N-methyl-benzeneacetamide (570 mg; 0.91 mmol) was dissolved in methanol (9 mL), and potassium carbonate (250 mg; 1.8 mmol; 2 eq) was added in one portion. Stirring continued at room temperature for about an hour, at which point the reaction mixture was diluted with water and the extracted with diethyl ether (10 mL). The combined organic layers were washed with saturated sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated to give the desired product (336 mg, 82%) as a white solid (M.P. 48-53° C.). The following table identifies several compounds of Formula (1) of the formula below prepared analogous to the various procedures illustrated in the preceding examples: Example X W R 1 R 2 R 3 1 3-chloro H H H phenyl 2 3-chloro H t-butyldimethylsilyl H H 3 3-chloro H Phenyl H H 4 3-chloro H Benzoyl H H 5 3-chloro H 2-pyridyl H H 6 3-chloro H H H 2,4-dimethyl phenyl 7 3-chloro H H H 4-fluoro phenyl 8 3-chloro H Trimethylacetyl H H 9 3-chloro H H H 4-chloro phenyl 10 3-chloro H H H 4-t-butyl phenyl 11 3-chloro H H H 4-methoxy phenyl 12 3-chloro H H H 3-trifluoro methylphenyl 13 3-methyl H H H phenyl 14 3-methyl H H H 4-fluoro phenyl 15 3-methyl H H H 4-chloro phenyl 16 3-chloro H H H 4-trifluoro methoxyphenyl 17 3-chloro H 4-methoxybenzyl H methyl 18 3-methyl fluoro H H phenyl 19 3-methyl fluoro H H 4-fluoro phenyl 20 3-methyl fluoro H H 4-chloro phenyl 21 3-methyl chloro H H phenyl 22 3-methyl chloro H H 4-fluoro phenyl 23 3-methyl chloro H H 4-chloro phenyl 24 3-chloro H Trimethylacetyl H methyl 25 3-chloro H 4-methoxybenzyl H H 26 3-chloro H H methyl phenyl 27 3-chloro H 4-chlorobenzyl H methyl 28 3-chloro H Acetyl H phenyl 29 3-chloro H Benzoyl H phenyl 30 3-chloro H Trimethylacetyl H phenyl 31 3-chloro fluoro H H phenyl 32 3-chloro H Isobutyryl H phenyl 33 3-chloro H Ethoxycarbonyl H phenyl 34 3-chloro H H methyl methyl 35 3-chloro H Methyl methyl phenyl 36 3-chloro H Propionyl H phenyl 37 3-chloro H Trifluoroacetyl H phenyl 38 3-chloro H Methyl H phenyl 39 3-chloro fluoro Methyl H phenyl 40 3-chloro H H H methyl 41 3-chloro H n-pentyl H methyl 42 3-chloro H H ethyl phenyl 43 3-chloro H H H isopropyl 44 3-chloro H 4-methylbenzyl H methyl 45 3-chloro H Dimethylcarbamoyl H phenyl 46 3-chloro H Acetyl H 4-fluoro phenyl 47 3-chloro H Butyryl H phenyl 48 3-chloro H Propionyl H 4-fluoro phenyl 49 3-chloro H H H 2-naphthyl 50 3-chloro H Butyryl H 4-fluoro phenyl 51 3-chloro H H H 2-thienyl 52 3-chloro H Benzyl H methyl 53 3-chloro H Acetyl methyl phenyl 54 3-chloro H Formyl H phenyl 55 3-chloro H Diethylphosphoryl H phenyl 56 3-chloro H Isopropoxycarbonyl H phenyl 57 3-chloro H Tetrahydropyranyl H phenyl 58 3-chloro H H H 3,4-methylene dioxyphenyl 59 3-chloro H H H o-tolyl 60 3-chloro H Acetyl H 3,4-methylene dioxyphenyl 61 3-chloro H Acetyl H o-tolyl 62 3-chloro H 3-methoxybenzyl H methyl 63 3-chloro H Ethoxyacetyl H phenyl 64 3-chloro H Methoxyacetyl H phenyl 65 3-chloro H H H 2-fluoro phenyl 66 3-chloro H H H 2-3-chloro phenyl 67 3-chloro H Triethylsilyl H phenyl 68 3-chloro H Methoxycarbonyl H phenyl 69 3-chloro H Ethyl H phenyl 70 3-chloro H H H p-tolyl 71 3-chloro H Acetyl H p-tolyl 72 3-chloro H H H phenyl 73 3-chloro H H H 3-3-chloro phenyl 74 3-chloro H Acetyl H 2-3-chloro phenyl 75 3-chloro H Acetyl H 3-3-chloro phenyl 76 3-chloro H Acetyl H phenyl 77 3-chloro H Acetyl H 2-thienyl 78 3-chloro H Acetyl H 4-trifluoro methoxyphenyl 79 3-chloro H Methyl H 4-trifluoro methoxyphenyl 80 3-chloro H n-butyl H methyl 81 3-chloro H H H 2-trifluoro methylphenyl 82 3-chloro H Acetyl H 2-fluoro phenyl 83 3-chloro H Acetyl H 2-naphthyl 84 3-chloro H H H m-tolyl 85 3-chloro H H H m-tolyl 86 3-chloro H H hydroxy phenyl methyl 87 3-chloro H H H cyclohexyl 88 3-chloro H Acetyl H 2-trifluoro methylphenyl 89 3-chloro H 4-methoxyphenyl H methyl 90 3-chloro H H H ethyl 91 3-chloro H Acetyl H ethyl 92 3-chloro H Acetyl H 2,4-dimethyl phenyl 93 3-chloro H H H 3-fluoro phenyl 94 3-chloro H H 4-toluene phenyl sulphonyl oxymethyl 95 3-chloro H Acetyl H 4-methoxy phenyl 96 3-chloro H Acetyl H 3-fluoro phenyl 97 3-chloro H 2-methoxybenzyl H methyl 98 3-methyl H Acetyl H phenyl 99 3-chloro H Methyl H 2-fluoro phenyl 100 3-chloro H H H 4-phenoxy phenyl 101 3-chloro H 4-methoxybenzyl H phenyl 102 3-chloro H H H 4-trifluoro methylphenyl 103 3-chloro H H H 1-naphthyl 104 3-chloro H 5-3-chloro-3-methyl- H methyl 2-pyridyl 105 3-chloro H H H 2-pyridyl 106 3-chloro H Acetyl H m-tolyl 107 3-chloro H Acetyl acetoxy phenyl methyl 108 3-chloro H Acetyl H 2-pyridyl 109 3-chloro H H H 3-thienyl 110 3-chloro H H H 3,4-dimethoxy phenyl 111 3-chloro H 2-fluoroethyl H methyl 112 3-chloro H Acetyl H m-tolyl 113 3-chloro H Ethyl H methyl 114 3-chloro H Methyl H m-tolyl 115 4-methoxy H Methyl H m-tolyl 116 3-chloro H Acetyl H 3,4-dimethoxy phenyl 117 3-chloro H Isopropyl H phenyl 118 3-chloro H 2-ethoxyethyl H phenyl 119 3-chloro H t-butyl H phenyl 120 3-chloro H n-propyl H phenyl 121 3-chloro H Acetyl H 3-thienyl 122 3-chloro H Ethyl methyl phenyl 123 3-chloro H —C(CH 3 ) 2 OCH 2 — phenyl 124 3-chloro H —CH 2 — phenyl 125 3-chloro H —C(═S)—OCH 2 — phenyl The compounds of Formula (1) thus produced are usually obtained as a mixture of the E and Z forms, which can then be separated, via standard means known in the art, into each of those forms, if desired. The compounds of Formula (1) show strong fungicidal activity against a wide variety of fungi. The following tests illustrate the fungicidal efficacy of the compounds of this invention. Fungicide Utility The compounds of the present invention have been found to control fungi, particularly plant pathogens. When employed in the treatment of plant fungal diseases, the compounds are applied to the plants in a disease inhibiting and phytologically acceptable amount. Application may be performed before and/or after the infection with fungi on plants. Application may also be made through treatment of seeds of plants, soil where plants grow, paddy fields for seedlings, or water for perfusion. The compounds may also be employed effectively for the control of fungi on wood, leather, carpet backings, or in paint. As used herein, the term “disease inhibiting and phytologically acceptable amount” refers to an amount of a compound of the present invention which kills or inhibits the plant disease for which control is desired but is not significantly toxic to the plant. This amount will generally be from about 1 to 1000 ppm, with 10 to 500 ppm being preferred. The exact concentration of compound required varies with the fungal disease to be controlled, the type of formulation employed, the method. of application, the particular plant species, climate conditions, and the like. A suitable application rate is typically in the range from about 0.10 to about 4 lb/A. The compounds of the invention may also be used to protect stored grain and other non-plant loci from fungal infestation. The following experiments were performed in the laboratory to determine the fungicidal efficacy of the compounds of the invention. Compound Formulation Compound formulation was accomplished by dissolving technical materials in acetone, with serial dilutions then made in acetone to obtain desired rates. Final treatment volumes were obtained by adding nine volumes 0.05% aqueous Tween-20 or Triton X-100, depending upon the pathogen. Late Blight of Tomatoes ( Phytophthora infestans —PHYTIN) Tomatoes (cultivar Rutgers) were grown from seed in a soilless peat-based potting mixture (Metromix) until the seedlings were 1-2 leaf (BBCH 12). These plants were then sprayed to run off with the test compound at a rate of 100 ppm. After 24 hours the test plants were inoculated with an aqueous spore suspension of Phytophthora infestans . The plants were then transferred to the greenhouse until disease developed on the untreated control plants. Powdery Mildew of Wheat ( Erysiphe graminis —ERYSGT) Wheat (cultivar Monon) was grown in a soilless peat-based potting mixture (Metromix) until the seedlings were 1-2 leaf (BBCH 12). These plants were then sprayed to run off with the test compound at a rate of 100 ppm. After 24 hours the test plants were inoculated with Erysiphe graminis by dusting spores from stock plants onto the test plants. The plants were then transferred to the greenhouse until disease developed on the untreated control plants. Glume Blotch of Wheat ( Leptosphaeria nodorum —LEPTNO) Wheat (cultivar Monon) was grown from seed in a soilless peat-based potting mixture (Metromix) until the seedlings were 1-2 leaf (BBCH 12). These plants were then sprayed to run off with the test compound at a rate of 100 ppm. After 24 hours the test plants were inoculated with an aqueous spore suspension of Leptosphaeria nodorum . The plants were then transferred to the greenhouse until disease developed on the untreated control plants. Brown Rust ( Puccinia recondita —PUCCRT) Wheat (cultivar Monon) was grown from seed in a soilless peat-based potting mixture (Metromix) until the seedlings were 1-2 leaf (BBCH 12). These plants were then sprayed to run off with the test compound at a rate of 100 ppm. After 24 hours the test plants were inoculated with an aqueous spore suspension of Puccinia recondita . The plants were then transferred to the greenhouse until disease developed on the untreated control plants. Septoria Leaf Spot ( Septoria tritici —SEPTTR) Wheat (cultivar Monon) was grown from seed in a soilless peat-based potting mixture (Metromix) until the seedlings were 1-2 leaf (BBCH 12). These plants were then sprayed to run off with the test compound at a rate of 100 ppm. After 24 hours the test plants were inoculated with an aqueous spore suspension of Septoria tritici . The plants were then transferred to the greenhouse until disease developed on the untreated control plants. The following table presents the activity of typical compounds of the present invention when evaluated in these experiments. The effectiveness of the test compounds in controlling disease was rated using the following scale: blank space=not tested −=0-24% control of plant disease +=25-74% control of plant disease ++=75-100% control of plant disease Example ERYSGT PUCCRT LEPTNO SEPTTR PHYTIN 1 ++ ++ ++ ++ 6 ++ ++ − ++ 7 ++ ++ ++ ++ 9 ++ ++ ++ ++ 10 ++ ++ ++ ++ 12 ++ ++ ++ ++ 13 ++ ++ ++ ++ 14 ++ ++ ++ ++ 15 ++ ++ ++ ++ 16 ++ ++ ++ − 17 ++ ++ ++ − 18 ++ ++ ++ ++ 19 ++ ++ ++ + 20 ++ ++ ++ ++ 21 ++ ++ ++ ++ 22 ++ ++ ++ ++ 23 ++ ++ ++ ++ 24 ++ ++ ++ − 25 ++ ++ ++ + 26 ++ ++ ++ ++ 27 ++ ++ ++ − 28 − ++ ++ − 29 + ++ ++ + 30 + ++ ++ ++ 31 + ++ − ++ 32 − ++ − − 33 + ++ ++ ++ 34 − ++ + + 35 ++ ++ ++ − 36 + ++ ++ ++ 37 + ++ ++ ++ 38 + ++ ++ − 39 + ++ ++ − 40 + ++ ++ + 41 ++ ++ ++ − 42 ++ ++ ++ ++ 43 ++ ++ + ++ 44 ++ ++ ++ ++ 45 ++ ++ ++ ++ 46 ++ − ++ − 47 ++ ++ ++ ++ 48 ++ ++ ++ ++ 49 ++ ++ ++ ++ 50 ++ ++ ++ ++ 51 ++ ++ ++ ++ 52 ++ ++ ++ − 53 ++ ++ ++ ++ 54 ++ ++ ++ ++ 55 ++ ++ ++ ++ 56 ++ ++ ++ ++ 57 ++ ++ ++ ++ 58 ++ ++ ++ ++ 59 ++ ++ ++ ++ 60 ++ ++ ++ ++ 61 ++ ++ ++ ++ 62 ++ ++ ++ − 63 ++ ++ ++ ++ 64 ++ ++ + ++ 65 ++ ++ ++ ++ 66 ++ ++ ++ ++ 67 ++ ++ ++ = = 68 ++ ++ − ++ 69 ++ ++ ++ − 70 ++ ++ ++ ++ 71 ++ ++ ++ ++ 72 ++ ++ ++ ++ 73 ++ ++ ++ ++ 74 ++ ++ ++ ++ 75 ++ ++ ++ ++ 76 ++ ++ ++ ++ 77 ++ ++ ++ ++ 78 ++ ++ ++ ++ 79 ++ ++ ++ − 80 ++ ++ ++ − 81 ++ ++ + ++ 82 ++ ++ ++ ++ 83 ++ ++ ++ ++ 84 ++ ++ − ++ 85 ++ ++ ++ − 86 − ++ − ++ 87 ++ ++ ++ ++ 88 ++ ++ ++ ++ 89 ++ ++ ++ ++ 90 ++ ++ + ++ 91 ++ ++ ++ ++ 92 ++ ++ ++ ++ 93 ++ ++ ++ ++ 94 ++ ++ ++ ++ 95 ++ ++ ++ ++ 96 ++ ++ ++ ++ 97 ++ ++ ++ − 98 ++ ++ ++ ++ 99 ++ ++ ++ − 100 ++ ++ ++ ++ 101 ++ ++ + ++ 102 ++ ++ ++ ++ 103 + ++ ++ ++ 105 ++ ++ ++ ++ 106 ++ ++ ++ ++ 107 ++ ++ ++ ++ 108 ++ ++ ++ ++ 109 ++ ++ ++ ++ 110 ++ ++ ++ ++ 112 ++ ++ ++ ++ 114 ++ ++ ++ − 115 + ++ ++ − 116 ++ ++ ++ + 117 ++ ++ ++ − 118 ++ ++ ++ − 119 ++ ++ ++ ++ 120 ++ − + + 121 ++ ++ 122 ++ − 123 ++ ++ ++ ++ 124 ++ ++ ++ ++ 125 ++ ++ ++ ++ blank space = not tested − = 0-24% control of plant disease + = 25-74% control of plant disease ++ = 75-100% control of plant disease The compounds of this invention are preferably applied in the form of a composition comprising one or more of the compounds of Formula (1) with a phytologically-acceptable carrier. The compositions are either concentrated formulations which are dispersed in water or another liquid for application, or are dust or granular formulations which are applied without further treatment. The compositions are prepared according to procedures which are conventional in the agricultural chemical art, but which are novel and important because of the presence therein of the compounds of this invention. Some description of the formulation of the compositions is given to assure that agricultural chemists can readily prepare desired compositions. The dispersions in which the compounds are applied are most often aqueous suspensions or emulsions prepared from concentrated formulations of the compounds. Such water-soluble, water suspendable, or emulsifiable formulations are either solids, usually known as wettable powders, or liquids, usually known as emulsifiable concentrates or aqueous suspensions. The present invention contemplates all vehicles by which the compounds of this invention can be formulated for delivery for use as a fungicide. As will be readily appreciated, any material to which these compounds can be added may be used, provided they yield the desired utility without significant interference with activity of the compounds of this invention as antifungal agents. Wettable powders, which may be compacted to form water dispersible granules, comprise an intimate mixture of the active compound, an inert carrier and surfactants. The concentration of the active compound is usually from about 10% to about 90% w/w, more preferably about 25% to about 75% w/w. In the preparation of wettable powder compositions, the toxicant products can be compounded with any of the finely divided solids, such as prophyllite, talc, chalk, gypsum, Fuller's earth, bentonite, attapulgite, starch, casein, gluten, montmorillonite clays, diatomaceous earths, purified silicates or the like. In such operations, the finely divided carrier is ground or mixed with the toxicant in a volatile organic solvent. Effective surfactants, comprising from about 0.5% to about 10% of the wettable powder, include sulfonated lignins, naphthalenesulfonates, alkylbenzenesulfonates, alkyl sulfates, and non-ionic surfactants, such as ethylene oxide adducts of alkyl phenols. Emulsifiable concentrates of the compounds of this invention comprise a convenient concentration, such as from about 10% to about 50% w/w, in a suitable liquid. The compounds are dissolved in an inert carrier, which is either a water miscible solvent or a mixture of water-immiscible organic solvents, and emulsifiers. The concentrates may be diluted with water and oil to form spray mixtures in the form of oil-in-water emulsions. Useful organic solvents include aromatics, especially the high-boiling naphthalenic and olefinic portions of petroleum such as heavy aromatic naphtha. Other organic solvents may also be used, such as, for example, terpenic solvents, including rosin derivatives, aliphatic ketones, such as cyclohexanone, and complex alcohols, such as 2-ethoxyethanol. Emulsifiers which can be advantageously employed herein can be readily determined by those skilled in the art and include various nonionic, anionic, cationic and amphoteric emulsifiers, or a blend of two or more emulsifiers. Examples of nonionic emulsifiers useful in preparing the emulsifiable concentrates include the polyalkylene glycol ethers and condensation products of alkyl and aryl phenols, aliphatic alcohols, aliphatic amines or fatty acids with ethylene oxide, propylene oxides such as the ethoxylated alkyl phenols and carboxylic esters solubilised with the polyol or polyoxyalkylene. Cationic emulsifiers include quaternary ammonium compounds and fatty amine salts. Anionic emulsifiers include the oil-soluble salts (e.g., calcium) of alkylaryl sulphonic acids, oil soluble salts or sulphated polyglycol ethers and appropriate salts of phosphated polyglycol ether. Representative organic liquids which can be employed in preparing the emulsifiable concentrates of the present invention are the aromatic liquids such as xylene, propyl benzene fractions; or mixed naphthalene fractions, mineral oils, substituted aromatic organic liquids such as dioctyl phthalate; kerosene; dialkyl amides of various fatty acids, particularly the dimethyl amides of fatty glycols and glycol derivatives such as the n-butyl ether, ethyl ether or methyl ether of diethylene glycol, and the methyl ether of triethylene glycol. Mixtures of two or more organic liquids are also often suitably employed in the preparation of the emulsifiable concentrate. The preferred organic liquids are xylene, and propyl benzene fractions, with xylene being most preferred. The surface active dispersing agents are usually employed in liquid compositions and in the amount of from 0.1 to 20 percent by weight of the combined weight of the dispersing agent and active compound. The active compositions can also contain other compatible additives, for example, plant growth regulators and other biologically active compounds used in agriculture. Aqueous suspensions comprise suspensions of water-insoluble compounds of this invention, dispersed in an aqueous vehicle at a concentration in the range from about 5% to about 50% w/w. Suspensions are prepared by finely grinding the compound, and vigorously mixing it into a vehicle comprised of water and surfactants chosen from the same types above discussed. Inert ingredients, such as inorganic salts and synthetic or natural gums, may also be added to increase the density and viscosity of the aqueous vehicle. It is often most effective to grind and mix the compound at the same time by preparing the aqueous mixture and homogenizing it in an implement such as a sand mill, ball mill, or piston-type homogenizer. The compounds may also be applied as granular compositions, which are particularly useful for applications to the soil. Granular compositions usually contain from about 0.5% to about 10% w/w of the compound, dispersed in an inert carrier which consists entirely or in large part of coarsely divided attapulgite, bentonite, diatomite, clay or a similar inexpensive substance. Such compositions are usually prepared by dissolving the compound in a suitable solvent and applying it to a granular carrier which has been preformed to the appropriate particle size, in the range of from about 0.5 to about 3 mm. Such compositions may also be formulated w by making a dough or paste of the carrier and compound, and crushing and drying to obtain the desired granular particle. Dusts containing the compounds are prepared simply by intimately mixing the compound in powdered form with a suitable dusty agricultural carrier, such as, for example, kaolin clay, ground volcanic rock, and the like. Dusts can suitably contain from about 1% to about 10% w/w of the compound. The active compositions may contain adjuvant surfactants to enhance deposition, wetting and penetration of the compositions onto the target crop and organism. These adjuvant surfactants may optionally be employed as a component of the formulation or as a tank mix. The amount of adjuvant surfactant will vary from 0.01 percent to 1.0 percent v/v based on a spray-volume of water, preferably 0.05 to 0.5 percent. Suitable adjuvant surfactants include ethoxylated nonyl phenols, ethoxylated synthetic or natural alcohols, salts of the esters or sulphosuccinic acids, ethoxylated organosilicones, ethoxylated fatty amines and blends of surfactants with mineral or vegetable oils. The composition may optionally include fungicidal combinations which comprise at least 1% of one or more of the compounds of this invention with another pesticidal compound. Such additional pesticidal compounds may be fungicides, insecticides, nematocides, miticides, arthropodicides, bactericides or combinations thereof that are compatible with the compounds of the present invention in the medium selected for application, and not antagonistic to the activity of the present compounds. Accordingly, in such embodiments the other pesticidal compound is employed as a supplemental toxicant for the same or for a different pesticidal use. The compounds in combination can generally be present in a ratio of from 1:100 to 100:1. The present invention includes within its scope methods for the control or prevention of fungal attack. These methods comprise applying to the locus of the fungus, or to a locus in which the infestation is to be prevented (for example applying to cereal or grape plants), a fungicidal amount of one or more of the compounds of this invention or compositions. The compounds are suitable for treatment of various plants at fungicidal levels, while exhibiting low phytotoxicity. The compounds are useful in a protectant or eradicant fashion. The compounds of this invention are applied by any of a variety of known techniques, either as the compounds or as compositions including the compounds. For example, the compounds may be applied to the roots, seeds or foliage of plants for the control of various fungi, without damaging the commercial value of the plants. The materials are applied in the form of any of the generally used formulation types, for example, as solutions, dusts, wettable powders, flowable concentrates, or emulsifiable concentrates. These materials are conveniently applied in various known fashions. The compounds of this invention have been found to have significant fungicidal effect particularly for agricultural use. Many of the compounds are particularly effective for use with agricultural crops and horticultural plants, or with wood, paint, leather or carpet backing. In particular, the compounds effectively control a variety of undesirable fungi which infect useful plant crops. Activity has been demonstrated for a variety of fungi. It will be understood by those in the art that the efficacy of the compounds of this invention for the foregoing fungi establishes the general utility of the compounds as fungicides. The compounds of this invention have broad ranges of efficacy as fungicides. The exact amount of the active material to be applied is dependent not only on the specific active material being applied, but also on the particular action desired, the fungal species to be controlled, and the stage of growth thereof, as well as the part of the plant or other product to be contacted with the toxic active ingredient. Thus, all the active ingredients of the compounds of this invention, and compositions containing the same, may not be equally effective at similar concentrations or against the same fungal species. The compounds of this invention and compositions are effective in use with plants in a disease inhibiting and phytologically acceptable amount. The term “disease inhibiting and phytologically acceptable amount” refers to an amount of a compound which kills or inhibits the plant disease for which control is desired, but is not significantly toxic to the plant. This amount will generally be from about 1 to about 1000 ppm, with 10 to 500 ppm being preferred. The exact concentration of compound required varies with the fungal disease to be controlled, the type of formulation employed, the method of application, the particular plant species, climate conditions, and the like. A suitable application rate is typically in the range from about 0.10 to about 4 pounds/acre.

The present invention provides novel 2-methoxyimino-2-(pyridinyloxymethyl)phenyl acetamide compounds with (derivatised) hydroxyalkyl substituents on the pyridine ring, their use as fungicidal compounds, and their use in fungicidal compositions comprising at least one of the 2-methoxyimino-2-(pyridinyloxymethyl)phenyl acetamide compounds as the active ingredient.

BACKGROUND OF THE INVENTION The laws of conservation of kinetic energy and momentum explain why a hard bouncing ball hitting a line of similar balls stops completely along with the other balls except the one at the far end, which moves away after the collision with substantially all the kinetic energy. Similarly, the laws of conservation of kinetic energy and angular momentum explain the following: Suppose there is a bar of length 2R, with its center rotatably secured to a shaft of fixed position. Immediately in front of one end of the bar lies a ball of mass M. Now someone throws another ball of the same kind at the other end of the bar. If at the instant of collision, the inertia of the bar and each ball are the same relative to the shaft, i.e., if MR 2 equals the inertia of the bar, then the incoming ball stops completely with the bar, and only the other ball is returned. If the bar is of a certain shape so that the other ball bounces back at a 45° C. elevation, then it can travel high and far despite energy losses during the collision. SUMMARY OF THE INVENTION Following the theory explained above, the ball exchanger of the present invention comprises a ball receiver connected to a bat, which is pivotably secured to a shaft. The ball receiver has to be large; otherwise one may miss it every time. The apparent inertia of the ball relative to the receiver tends to vary over a large range depending upon the precise point of impact of the ball. Therefore, the inertia of the ball and receiver cannot be properly matched. The incoming ball might bounce back or move forward with the receiver, either movement resulting in wasted energy. This problem is solved, however, by supporting the receiver in such a way that it maintains a predetermined position with respect to the ball. In one form of the invention, there is accomplished by an arrangement of parallel bars and parallel shafts connected so as to transfer the energy in substantially the same manner regardless of the point of impact on the receiver. Other features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof and the attached drawings which illustrates, by way of example, the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the ball exchanger with the collector removed; FIG. 2 is a plane view of the bars of the ball exchanger reinforced by a cross frame; FIG. 3 is a fragmentary, perspective view showing the collector of the ball exchanger; and FIG. 4 is a plane view, on a reduced scale, of the ball exchanger including the collector. DESCRIPTION OF THE PREFERRED EMBODIMENT An exemplary ball exchanger embodying many novel features of the present invention is shown in FIGS. 1-4. It includes a ball receiver 1 that is rigidly connected to two frame pieces 2 and 3 to first and second shafts 4 and 5. The shafts 4 and 5 are therefore movable back and forth with the receiver 1. Two parallel bars 6 and 7 each have one end rotatably secured to the first movable shaft 4 and the other end rotatably secured to a first fixed shaft 8. Both fixed shafts 8 and 9 are attached to a base 11 which may be either heavy or light, but is equipped with means (not shown) to facilitate its attachment to external supports such as tables, walls, or trees. A shock absorber 12 is mounted on the base 11. A cross framework 13 strengthens the parallel bars 6 and 7 (as shown in FIG. 2) and a similar cross framework (not shown) is used between the frames 2 and 3. The movable shafts 4 and 5, the first fixed shaft 8 and a second fixed shaft 9 are parallel to each other and always form the four corners of a parallelogram as the ball receiver 1 recoils, thereby mounting the ball receiver in a fixed vertical orientation. A bat 10 is pivotably secured to the second fixed shaft 9 and has one end rotatably secured to the second movable shaft 5 nearest the receiver 1 (see FIG. 4). A ball collector 14, having a hole 15 at the bottom, is secured by support 16 to the body 11 and stored ball 17 sits in the hole 15 ready to be struck by the bat 10. One must consider the inertial forces relative to the second fixed shaft 9 at the instant of collision. The inertia of the parts that are movable with respect to the base 11 may be termed "machine inertia". Whatever point on the ball receiver 1 is struck by an incoming ball or other object, the ball receiver 1 together with the frames 2 and 3 may be considered as centered at the level of the movable shafts 4 and 5 insofar as the inertia is concerned. The incoming ball may, therefore, be considered as if it has hit those shafts. Since inertia is quadratically proportional to the distance of the impact from the fixed shaft 9, the ball receiver 1, together with the frames 2 and 3, contributes the major part of said machine inertia. For the inertia of the incoming ball to be equal to the machine inertia, the total weight of the ball receiver 1 together with frames 2 and 3 is designed to be slightly less than the weight of the incoming ball. The inertia of the stored ball 17 relative to the shaft 9 is easily adjusted by properly locating the hole 15 to give the maximum efficiency. With no ball stored in the collector 14, the incoming ball hits the ball receiver 1, stops because its inertia is equal to the machine inertia, then drops into the collector 14 toward the hole 15, and finally becomes the stored ball for use later. The ball receiver 1 recoils and causes the parallel bars 6 and 7 as well as the bat 10 to move, but their motion is soon arrested by the shock absorber 12. Since there is no perfect shock absorber, the ball receiver 1 bounces back a little bit, and is then restored to its normal position by gravity or the force of a light spring (not shown). If a stored ball 17 is sitting in the hole 15 when the incoming ball hits the ball receiver 1, the receiver recoils and causes the bat 10 to move. The bat 10 then hits the stored ball 17 at the designed elevation. Due to proper inertia design as discussed above, tha bat 10, the ball receiver 1, and the incoming ball combined have very little kinetic energy after the collision, and the stored ball 17 alone bounces back with almost all of the kinetic energy. The incoming ball again becomes the stored ball for the next operation of the device. Since the ball receiver 1 and the bat 10 move very little, frictional losses at the shafts 4, 5, 8 and 9 are negligible. It can be seen from FIG. 1 that the vibration loss is also minimized due to the support of the frame pieces 2 and 3 and the special shape of the bat 10. Furthermore, the bottom ends of the parallel bars 6 and 7, although rotatably secured to the fixed shafts 8, have relatively fixed positions, as does the bat 10, with respect to the shaft 9. Therefore, if the incoming ball hits the left or right side of the ball receiver 1, the torque which tends to rotate the ball receiver 1 is opposed by the parallel relationship between the movable shafts 4 and 5 on the one hand and the fixed shafts 7 and 6 on the other, this relationship being maintained by the bars 6 and 7 and the bat 10. The result is only a slight increase in friction losses when the impact is off-center laterally, and this increase is still negligible as all parts move very little during collision. Therefore, the energy loss is minimized, and, by using balls that bounce well, the stored ball 17 can indeed be sent back a great distance. The particular design described above is the preferred arrangement to keep the ball receiver 1 in a predetermined orientation as it recoils, so that the inertia of the incoming ball relative to the machine remains the same for different impact points. One may, however, use a bar fixedly attached behind the ball receiver 1 and extending in the direction of movement of the incoming ball. The bar which is used in place of the movable supporting structure described above slides smoothly in a tube-like structure and is supported by small wheel-like bearings to decrease friction. The upper end of the bat 10 is in the recoiling direction of the bar. This modified machine will function much the same as that shown in FIG. 1. Alternatively, the ball receiver 1 may be fixed directly to the bat 10, without the frames 2 and 3 or parallel bars 6 and 7. But then the area of the ball receiver 1 has to be small for the reasons previously discussed. To shoot accurately, it is then better that the incoming ball be fired from a mechanical ejector rather than thrown with the hands. The ball receiver 1 and bat 10 can also be built in duplicate, so that each will function in the same manner as the other. Two collectors may then be used. In another variation of the invention, the collector 14 may be fixedly attached to the bat 10, instead of the body 11, but the efficiency is not as high. While particular forms of the invention have been described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.

A ball game machine, which after being hit by an incoming ball, will return another ball with a minimum loss of energy. The incoming ball stops at the ball receiver and transmits almost all of its kinetic energy to the machine through proper inertia design. Instantaneously, the recoiling ball receiver mechanically causes a bat to strike a second ball which has been stored in a collector. The incoming ball then drops into the collector and becomes a stored ball so that the operation can be repeated.

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This is a continuation of application Ser. No. 10/760,069 entitled “Barrier Movement Operator Having Obstruction Detection” filed Jan. 16, 2004 having inventors Robert Keller and Colin Willmott and which is incorporated herein by reference in its entirety. BACKGROUND [0002] The present invention relates to barrier movement operators and particularly to barrier movement operators having improved characteristics for detecting obstructions to the movement of the barrier. [0003] Barrier movement operators generally comprise an electric motor coupled to a barrier and a controller which responds to user input signals to selectively energize the motor to move the barrier. The controller may also respond to additional input signals, such as those from photo-optic sensors sensing an opening over which the barrier moves, to control motor energization. For example, should a photo optic sensor detect an obstruction present in the barrier opening, the controller may respond by stopping and/or reversing motor energization to stop and/or reverse barrier movement. The controller may also respond to motor speed representing signals by controlling motor energization. Such may be used to stop and/or reverse the movement of a barrier when the motor speed, which represents the speed of movement of the barrier, falls below a predetermined amount as might occur if the barrier has contacted an obstruction to its movement. [0004] Detecting contact by the barrier with an obstacle by sensing the driving speed of the motor has certain inherent difficulties. The barrier, barrier guide system and the connection between the barrier and the motor all have momentum and all exhibit some amount of flexibility. When the leading edge of a barrier is slowed, it takes time for the inertia of the various parts to be overcome and for the slowing of the barrier to be reflected back to the motor via the flexible (springy) interconnection. Through proper design and construction techniques, such systems have been successfully achieved for response times and contact pressure thresholds to achieve safe operation. However, to achieve ever safer operation involving lower barrier contact forces and more rapid response times, new designs are needed. [0005] Motors for use with barrier movement operators are generally constructed or selected to operate efficiently and exhibit a motor rotation rate (motor speed) to torque characteristic represented in FIG. 4 . The normal forces on the barrier generally allow the operating motor speed between the marks labeled A and B on FIG. 4 resulting in a relatively flat slope of the speed versus torque characteristic. The “normal” motor having a characteristic as shown in FIG. 4 exhibits a change of motor RPM of approximately 20 RPM per inch-pound of required motor torque. Improvements in obstruction contact times and reduction of obstruction contact forces is difficult with a motor having the characteristics of FIG. 4 because the change of motor RPM is small for the normal range of obstruction forces. A need exists for a motor which operates with a torque to speed characteristic which is enhanced for rapid obstacle detection. [0006] Improvements in barrier contact obstacle detection may also be achieved by improvements in how sensed motor speed changes are interpreted. Existing barrier movement systems include obstacle detection functions which compare currently measured motor speed with an obstacle indicating threshold. The obstacle indicating threshold generally consists of an expected motor speed minus a constant which defines how much additional speed reduction represents an obstacle rather than a normal variation in operating speed. In some systems an average speed is assumed for the entire movement between open and closed positions and when motor speed falls below the normal speed minus a fixed threshold an obstacle is assumed. In other systems a speed history is determined for door movement by recording measured speeds at several (many) points along barrier travel. When the measured speed falls below the speed history for the same point in barrier travel minus a fixed threshold, an obstacle is assumed. Improvements are needed in obstacle detection to permit fine control of speed changes which indicate an obstruction. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 shows a barrier movement system connected to a vertically moving garage door; [0008] FIG. 2 is a block diagram of the control apparatus for a barrier movement operator; [0009] FIG. 3 illustrates circuitry for detecting motor rotation speed; [0010] FIG. 4 is a graph of motor rotation speed versus required motor torque for existing induction A.C. motors; [0011] FIG. 5 is a graph of motor rotation speed versus required motor torque for enhanced A.C. induction motor operation; [0012] FIG. 6 is a diagram of a modified A.C. voltage which may be used to power A.C. motors; [0013] FIG. 7 is a graph representing motor speed and obstacle detection thresholds; [0014] FIGS. 8A and B represent the stator and field windings of an A.C. induction motor; [0015] FIGS. 9A and B represent the rotor of an A.C. induction motor; and [0016] FIG. 10 is a graph of motor torque versus motor current for normal and one enhanced induction A.C. motor. DESCRIPTION [0017] FIG. 1 illustrates the use of a barrier movement operator 10 for vertically moving a garage door. It should be understood that a barrier movement operator as described and claimed herein may be used to move other types of barrier such as gates, window shutters and the like. Barrier movement operator 10 includes a head unit 12 mounted within a garage 14 . The head unit 12 is mounted to the ceiling of the garage 14 and includes a rail 18 extending therefrom with a releasable trolley 20 attached having an arm 22 extending to a multiple paneled garage door 24 positioned for movement along a pair of door rails 26 and 28 . The system includes a hand-held transmitter unit 30 adapted to send signals to an antenna 32 positioned on the head unit 12 and coupled to a receiver as will appear hereinafter. A switch module 39 is mounted on a wall of the garage. The switch module 39 is connected to the head unit by a pair os wires 39 a and includes a command switch 39 b . An optical emitter 42 is connected via a power and signal line 44 to the head unit. An optical detector 46 is connected via a wire 48 to the head unit 12 . [0018] As shown in FIG. 2 , the garage door operator 10 , which includes the head unit 12 has a controller 70 which includes the antenna 32 . The controller 70 includes a power supply 72 which receives alternating current from an alternating current source, such as 110 volt AC, at a pair of conductors 132 and 134 , and converts the alternating current into DC which is fed along a line 74 to a number of other elements in the controller 70 . The controller 70 includes and rf receiver 80 coupled via a line 82 to supply demodulated digital signals to a microcontroller 84 . The microcontroller 84 includes a non-volatile memory, which non-volatile memory stores set points and other customized digital data related to the operation of the control unit. An obstacle detector 90 , which comprises the infrared emitter 42 and detector 46 is coupled via a bus 92 (which comprises lines 44 and 48 ) to the microcontroller. The obstacle detector bus 92 includes lines 44 and 48 . The wall switch 39 is connected to supply signals to and is controlled by the microcontroller. The microcontroller, in response to switch closures, will send signals over a relay logic line 102 to a relay logic module 104 which connects power to an alternating current motor 106 having a power take-off shaft 108 . A tachometer 110 is connected to shaft 108 and provides a tachometer signal on a tachometer line 112 to the microcontroller 84 . The tachometer signal being indicative of the speed of rotation of the motor. The tachometer 110 may comprise an interrupter wheel represented at 115 ( FIG. 3 ) connected to rotate with the motor shaft 108 . A light source 128 and light receiver 127 detect rotation of the shaft by detecting successive passings of a plurality of light blocking apparatuses 117 and reporting to controller 84 via communication path 112 . Microcontroller 84 can then determine current motor speed by calculating the period between successive light blockages. It should be mentioned that other means for detecting rotation rate may also be employed such as a cup shaped interrupter with equally spaced apertures therethrough to successively block and pass light between source 128 and detector 127 . The signals on conductor 112 from tachometer 110 may also be used to identify the position of the barrier when used with a pass point arrangement or position detector shown at 120 , which operation is known in the art. [0019] The barrier movement operator of FIG. 1 begins to move the barrier in response to a user pressing button 39 B of wall control 39 or pressing a transmit button of transmitter 30 . Generally, when movement begins the barrier is in the open or closed positions. When a command to move the barrier is received, the barrier driven toward the other limit. In the present embodiment the controller 10 tracks the position of the barrier in response to signals from tachometer 110 and formulates operations based on that sensed position. The controller also may respond to signals from optical detector 90 representing a possible obstruction by reversing the direction of a downwardly traveling barrier. [0020] The barrier movement operator of FIG. 1 also responds to sensed information about the forces required to move the barrier to control further barrier movement. For example, as the barrier is moved, motor speed is continuously checked as an indication of the forces being required to move the barrier. FIG. 4 is a graph of a normal motor showing motor rotation speed versus motor output torque. As the forces required to move the door increase the motor slows. The converse is also true. The predictable nature of speed change versus applied forces allows the motor speed to be used as an indication of such things as the barrier contacting an obstruction. [0021] Barrier movement operators have been constructed which respond to the motor speed falling below a fixed value by assuming that the barrier has contacted an obstruction and, accordingly, stop or reverse the travel of the barrier. More sophisticated systems have been designed which record measured motor speed at a number of barrier positions establish obstruction threshold histories for different barrier positions. FIG. 7 illustrates one such thresholding system in which 6 thresholds labeled 50 , 52 , 54 , 56 , 58 and 60 are shown. It should be mentioned that in FIG. 7 motor speed is represented by the period between successive light blockages from an interrupter wheel and as such higher on the graph of FIG. 7 represents lower motor speed. During movement of the barrier, a number of different motor speeds are sensed as represented by the measured speed line. Zones of interest are then selected and a value representing the minimum speed in each zone is recorded. In FIG. 7 , the minimum speed in a first zone is represented at 51 , a second at 53 and others at 55 , 57 , 59 and 61 . A predetermined speed difference value may then be subtracted from each minimum speed to establish the overall threshold for the zone. The references 50 , 52 , 54 , 56 , 58 and 60 represent the per zone thresholds. After the zone thresholds have been learned (or updated) whenever measured speed falls below the zone threshold an obstruction is assumed and the barrier is stopped or reversed. [0022] As shown in FIG. 7 each minimum threshold is a fixed amount different from the minimum speed in the zone as represented by the couplets 50 - 51 , 52 - 53 , 54 - 55 and 56 - 57 . In the present embodiment, particular zones can be configured to be more sensitive than other zones. For example, the period (speed) difference between 57 and 56 is the same as the period (speed) difference between all other couplets toward the open representing left of the graph. Thus, all zones from 56 - 57 to the left are of substantially equal sensitivity. The zone represented by the couplet 58 - 59 is more sensitive because less speed difference between the measured minimum 59 and the threshold 58 exists than between the other couplet to the left. As can be seen in FIG. 7 the most sensitive zone is near the closed position and advantageously is placed within 18 inches of the closed position. [0023] Other improvements to obstruction detection are made by the presently disclosed barrier movement system. FIG. 4 represents the speed versus torque characteristic for a normal motor. As can be seen the slope of the line from A to B which represents a normal operating range, an increase of required torque of one ft. lb. results in a motor speed change of only about 12-13 RPM. This is a relatively small change to be rapidly detected, particularly in the real environment as represented by the measured speed line of FIG. 7 . FIG. 5 represents in the speed versus torque characteristic of a motor and its driving apparatus which is enhanced to improve motor speed change. The slope of the line between points A 1 and B 1 on FIG. 5 results in a change of speed of approximately 47 to 48 RPM per inch-pound of torque thus making speed changes more easily detected. [0024] A characteristic as shown in FIG. 5 can be achieved by producing a motor with the appropriate parameters. FIGS. 8A and 8B are views of a field winding/stator of an induction motor. FIGS. 9A and 9B represent the induction rotor of such a motor. The rotor of an AC induction motor includes a plurality of ferris metal rotor lamination formed together into a cylinder as represented at 62 . The rotor laminations have a plurality of regularly spaced apertures which are arranged to extend from one end of the rotor cylinder at an angle as represented by 64 . The apertures are filled with an electrically conductive non-ferris metal such as aluminum. Finally end rings 64 are formed at the ends of the diagonal conductive lines 64 from non-ferris electrical conductors to provide conductive paths between the diagonals 64 . Due to current induced by AC applied to the field coils, magnetic fields are produced in the rotor which cause rotation. [0025] Normally motors are designed to provide very low resistance in the cross paths 64 and the end rings 66 resulting in a characteristic as shown in FIG. 4 . In the present embodiment, however, the resistances have been increased which results in an enhanced characteristic as shown in FIG. 5 . In a preferred embodiment the resistance increase was produced by using smaller than normal amounts of non-ferris metal for conductors 64 and 66 . The results could also be achieved by fabricating the conductors 64 and 66 from non-ferris material having greater internal resistance. [0026] In the above discussion the enhanced characteristic ( FIG. 5 ) was achieved during motor fabrication or selection. Such can also be achieved by selective coupling of incoming AC power to the motor 106 . In FIG. 2 incoming AC power is connected to conductor 132 and 134 which are in turn connected to a power control circuit 114 . An output of power control circuit 114 is used to power the motor. Power control circuit 114 selectively blocks portions of each cycle of the incoming sinusoidal AC wave form shown in FIG. 6 to the motor 106 via relay logic 104 . The wave form of FIG. 6 is achieved by a “light dimmer” circuit in power control which is preset to pass a predetermined percentage e.g., 60 percent of each sine wave cycle. Energization of an AC induction motor with a wave form shown in FIG. 6 results in a characteristic as shown in FIG. 5 . Greater control over the A.C. wave form applied to the motor 106 by using a power control circuit of the type described in U.S. patent application Ser. No. 10/622,214 filed 18 Jul. 2003 which is connected to microcontroller 84 via a control line 118 . Such greater control might include skipping entire cycles of applied A.C. Also the wave form of FIG. 6 may be reproduced using high frequency e.g., 1 KHZ duty cycle control. [0027] The preceding embodiment measured rotation speed of the motor to detect possible obstructions because motor speed represents present torque requirements of the motor. (See FIGS. 4 and 5 ) The current drawn by an induction A.C. motor also represents the present torque requirements of the motor. As the force requirements increase so does the current applied to the motor. The motor current may be sensed by an optional current sensor 130 connected to the A.C. inputs of the relay logic 104 . ( FIG. 2 ) This relationship is shown in FIG. 10 as 203 for a “normal” motor and 201 for a motor enhanced by the above described motor modifications and driving techniques. When motor current is sensed to detect possible obstructions, the enhanced characteristic 201 provides more rapid and certain obstruction detection. [0028] While there has been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

A barrier movement operator includes an A.C. motor having a rotatable rotor connected to a barrier for movement thereof. A sensing apparatus generates motor signals representing an operational variable of the motor. The movement of the barrier is controlled by a controller, which responds to the motor signals by selectively stopping rotation of the rotor or reversing the rotation of the rotor. A power control arrangement provides energizing power to the motor by receiving AC power input substantially in the form of a sine wave and conducts portions of successive cycles of the sine wave of the received AC power to the motor to enhance the sensed operational variable to torque characteristic of the motor.

[0001] This application claims priority under 35 U.S.C. § 120 as a continuation of co-pending U.S. application Ser. No. 10/961,592, filed Oct. 8, 2004, entitled “ULTRA-WIDEBAND COMMUNICATION SYSTEMS AND METHODS,” which is a continuation-in-part of U.S. application Ser. No. 09/670,054 filed Sep. 25, 2000 entitled “METHOD AND APPARATUS FOR WIRELESS COMMUNICATIONS,” now U.S. Pat. No. 7,031,371. TECHNICAL FIELD OF THE INVENTION [0002] The invention relates generally to ultra-wideband communications, and more particularly to systems and methods for communication using ultra-wideband technology. BACKGROUND OF THE INVENTION [0003] The electromagnetic spectrum used to convey radio communications is a precious commodity. Communication systems seek to use this spectrum as efficiently as possible to maximize the capacity or quantity of information, which can be conveyed using the spectrum. [0004] Various multiple access techniques have been developed to transfer information among a number of users, all while efficiently using spectrum. Time division multiple access (TDMA) techniques assign different users to different time slots. Capacity is hard limited by the number of time slots available. To prevent intolerable interference, the portion of the spectrum used in one radio coverage area or cell has conventionally been unusable in adjacent cells. Thus, only a fraction, typically less than one-third, of the entire spectrum available for conveying communications has been conventionally usable in any one location. In other words, conventional TDMA systems employ a frequency reuse pattern of at least three, indicating an inefficient use of spectrum. [0005] Conventional direct sequence spread spectrum (DSSS) code division multiple access (CDMA) techniques theoretically use the spectrum more efficiently than TDMA techniques. However, in practice conventional DSSS-CDMA techniques typically fail to provide results significantly better than TDMA. DSSS-CDMA techniques assign different users to different codes. The different codes have conventionally been selected because of orthogonality or low cross correlation properties with the codes of other users. These properties minimize interference. All communications are broadcast using the same spectrum, so the frequency reuse pattern equals one. While the commonly used spectrum conveys a composite of communications for all users, each individual user's communications are extracted from the composite by correlating a received signal against the individual user's assigned code. [0006] Capacity in conventional DSSS-CDMA systems is interference limited. In other words, more and more codes can be assigned so that the given amount of spectrum can service more and more users until interference reaches a level where only a minimally acceptable quality of service results. In practice, most conventional DSSS-CDMA systems can assign far fewer codes than appear theoretically possible due to a near-far effect and multipath. The near-far effect results when signals from different users are received with greatly differing field strengths, but this detrimental effect may be ameliorated somewhat by power control. [0007] Multipath results when the transmitted signal takes multiple paths to the receiver due to being reflected from and deflected around obstacles in the environment. As the signal propagates over the multiple paths, different propagation delays are experienced. Thus, a signal transmitted at a precise instant in time is received spread over an interval, causing the signal to interfere with itself. In conventional DSSS-CDMA communication systems, multipath tends to destroy the orthogonality of spreading codes, resulting in dramatically increased interference. SUMMARY OF THE INVENTION [0008] In order to combat the above problems, systems and methods described herein provide a novel ultra-wideband communication system. In one embodiment, an ultra-wideband communication system divides a stream of data conveying symbols into a plurality of unspread substreams. A common spreading code is generated at the ultra-wideband transmitter, and each of the unspread substreams are spread using the common spreading code to form a plurality of spread substreams. The spread substreams are combined to form a composite signal that is transmitted. [0009] In another embodiment, an ultra-wideband communication system comprises a demultiplexer for dividing a stream of data conveying symbols into a plurality of unspread substreams. A spreading section is coupled to the demultiplexer and configured to generate a plurality of spread substreams from the plurality of unspread substreams. A combining section is coupled to the spreading section and configured to form a composite signal from the plurality of spread substreams, and a transmission section is coupled to the combining section and configured to transmit the composite signal over an ultra-wideband communication channel. [0010] These and other features and advantages of the present invention will be appreciated from review of the following Detailed Description of the Preferred Embodiments, along with the accompanying figures in which like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the Figures, wherein like reference numbers refer to similar items throughout the Figures, and: [0012] FIG. 1 shows a layout diagram of an exemplary environment in which the present invention may be practiced; [0013] FIG. 2 shows a timing diagram, which depicts a temporal format of a TDMA communication signal; [0014] FIG. 3 shows a block diagram of a transmitter and a receiver configured in accordance with the teaching of the present invention; [0015] FIG. 4 shows a timing diagram depicting how a cyclic spreading code is applied to blocks of unspread data streams in accordance with first, second and third embodiments of a DSSS modulation section in the transmitter of the present invention; [0016] FIG. 5 shows a block diagram of the first embodiment of the DSSS modulation section; [0017] FIG. 6 shows a block diagram of the second embodiment of the DSSS modulation section; [0018] FIG. 7 shows a block diagram of the third embodiment of the DSSS modulation section; [0019] FIG. 8 shows a first embodiment of a CDM to TDM converter section in the receiver of the present invention; [0020] FIG. 9 shows an exemplary spectral analysis of a suitable spreading code usable in connection with the present invention, the spectral analysis showing a substantially flat response; [0021] FIG. 10 shows an exemplary timing diagram of various individual signal components present in a composite signal output from a matched filter portion of a mismatched filter in the CDM to TDM converter; [0022] FIG. 11 shows a timing diagram depicting how a cyclic spreading code is applied to blocks of unspread data streams in fourth and fifth embodiments of the DSSS modulation section; [0023] FIG. 12 shows a block diagram of the fourth and fifth embodiments of the DSSS modulation section; [0024] FIG. 13 shows a second embodiment of the CDM to TDM converter for use with the fourth embodiment of the DSSS modulation section; [0025] FIG. 14 shows a third embodiment of the CDM to TDM converter for use with the fifth embodiment of the DSSS modulation section; [0026] FIG. 15 is an illustration of different communication methods; and [0027] FIG. 16 is an illustration of two ultra-wideband pulses. [0028] It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The Figures are provided for the purpose of illustrating one or more embodiments of the invention with the explicit understanding that they will not be used to limit the scope or the meaning of the claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0029] In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. While this invention is capable of embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. That is, throughout this description, the embodiments and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s). [0030] The present invention provides several advantages and features, for example, the present invention combines TDMA and spread spectrum techniques so that wireless communications capacity is increased over the capacities achievable through conventional TDMA and/or CDMA systems using an equivalent amount of spectrum. [0031] Another advantage of the present invention is that robust, simple, and inexpensive processing techniques are usable, making the present invention suitable for hubs, subscriber units, mobile stations/fixed stations, portable stations, and the like. [0032] Another advantage is that the present invention may be adapted to and used in conjunction with a variety of modulation and multiple access techniques, such as frequency division multiple access (FDMA) and orthogonal frequency division multiplexing (OFDM). [0033] Another advantage of the present invention is that a composite RF communication signal includes signal components obtained by modulating diverse branches of a single user's data stream using cyclic variants of a common spreading code. [0034] Another advantage is that the present invention is configured to tolerate self-interference and is better able to tolerate multipath than conventional DSSS-CDMA communication systems. [0035] These and other features and advantages of the present invention will be appreciated from review of the following discussion: [0036] FIG. 1 shows a layout diagram of an exemplary environment in which a communication system 20 configured in accordance with the teaching of the present invention may be practiced. Communication system 20 includes any number of transmitters (TX's) 22 (three shown) and any number of receivers (RX's) 24 (five shown). Transmitters 22 wirelessly broadcast messages through RF time domain multiple access (TDMA) communication signals 26 which are receivable by receivers 24 located within radio coverage areas 28 for the transmitters 22 . Radio coverage areas 28 may also be called cells or sectors. As illustrated in FIG. 1 , various ones of radio coverage areas 2 8 may be adjacent to one another and even overlap to some extent. In the preferred embodiment, a common spectrum is used in all radio coverage areas 28 so that communication system 20 has a frequency reuse pattern substantially equal to one. [0037] For the sake of clarity, FIG. 1 depicts only a forward link in which radio equipment is viewed as being only a transmitter 22 or a receiver 24 . However, those skilled in the art will appreciate that a reverse link may also be implemented and that each item of equipment may have both a transmitter and receiver. The reverse link may use the same or a different spectrum from the forward link. If a forward link conforms to the teaching of the present invention, then the reverse link may or may not conform, and vice versa. [0038] FIG. 2 shows a timing diagram, which depicts an exemplary temporal format for TDMA communication signal 26 . FIG. 2 specifically depicts two frames 30 , each of which is temporally subdivided into any number of timeslots 32 . Different timeslots 32 are preferably assigned to different receivers 24 ( FIG. 1 ) in a manner well understood in the art so that different recipients are distinguished from one another by being assigned to the different time slots 32 . In the preferred embodiments, TDMA communication signal 26 consumes the entire common spectrum for each time slot 32 . Nothing requires a time slot 32 to be assigned to receivers 24 for an indefinite period or to be of the same duration as other time slots 32 . [0039] Each time slot 32 of TDMA communication signal 26 is subdivided into successive blocks 34 of symbols 36 . FIG. 2 labels blocks 34 with the identifiers B k , for k=0 to K−1, where K is an integer number. Any number of blocks 34 may be included in each timeslot 32 . Each block B k includes M symbols 36 , labeled as a k,m for m=0 to M−1, where M is an integer number. FIG. 2 illustrates each of symbols 36 within a block 34 as being concurrently present throughout the entire duration of a block period because certain preferred embodiments discussed below configure symbols 36 to remain present for block periods. [0040] FIG. 2 further illustrates that the M symbols 36 of each block 34 are spread using an N-chip spreading code 38 , labeled as C n , for n=0 to N−1, where N is an integer number. As discussed in more detail below, each symbol 36 is independently spread using cyclic variations of the same common code 38 . The number M of symbols 36 in a block may equal the number N of chips in a spreading code, in which case the spreading factor equals one. However, performance improvements result when N is greater than M. [0041] FIG. 3 shows a block diagram of a single transmitter 22 and a single receiver 24 configured in accordance with the teaching of the present invention. Those skilled in the art will appreciate that all transmitters 22 and receivers 24 may be configured similarly. In addition, any number of receivers 24 may, at any given instant, receive TDMA communication signal 26 from a given transmitter 22 and, in fact, may receive TDMA communication signals 26 from more than one transmitter 22 . [0042] Transmitter 22 includes a TDMA modulation section 40 , which generates a TDMA-configured stream 42 of data conveying symbols 36 . Stream 42 feeds a direct sequence spread spectrum (DSSS) modulation section 44 , which generates a composite signal 46 . Composite signal 46 feeds a transmission section 48 , which forms TDMA communication signal 26 from composite signal 46 and wirelessly broadcasts TDMA communication signal 2 6 for reception by receivers 24 located within radio coverage area 28 ( FIG. 1 ) of transmitter 22 [0043] Within TDMA modulation section 40 any number of data sources 50 supply digital data to a multiplexer (MUX) 52 . The digital data from data sources 50 may be intended for any number of receivers 24 . Multiplexer 52 groups the digital data so that data intended for different receivers 24 are serially fed to a cyclic redundancy check (CRC) section 54 in accordance with the assignment of timeslots 32 ( FIG. 2 ) to receivers 24 . CRC section 54 provides forward error correction in a manner well understood by those skilled in the art. [0044] From CRC section 54 , the input data stream may be fed through a scrambler 56 which randomizes the data to an encode and interleave section 58 . Section 58 may apply another type of error correction, such as convolutional or turbo encoding, to the input stream, and interleave the data. CRC section 54 and section 58 may utilize a form of block encoding. The block size or boundaries of such encoding need have no relationship to blocks 34 ( FIG. 1 ), discussed above. [0045] However, the output of section 58 feeds an optional peak-to-average (P/A) block encoding section 60 . P/A block encoding section 60 applies a type of encoding which primarily reduces the peak-to-average power ratio in composite signal 46 and thereby lessens the demands placed on a power amplifier included in transmission section 48 to faithfully reproduce communication signal 26 with a minimum amount of distortion. This type of encoding may, but is not required to, provide additional coding gain. In the preferred embodiments, when P/A block encoding section 60 is included, it applies block encoding so that encoded blocks coincide with successive blocks of symbols 36 ( FIG. 2 ), discussed above. In other words, the data are encoded so that P/A encoded blocks begin with symbol 36 a k,0 ( FIG. 2 ) and end with symbol 36 a k,m ( FIG. 2 ). [0046] P/A block encoding section 60 feeds a constellation encoding section 62 which converts the data into complex symbols in accordance with a predetermined phase constellation. As an example, each four-bit group of data output from P/A block encoding section 60 may be mapped by section 62 into a single complex symbol having in-phase and quadrature components in accordance with a 16-QAM phase constellation. However, those skilled in the art will appreciate that the present invention may be used with any type or size of phase constellation. [0047] The stream of complex symbols output from constellation encode section 62 passes through a synchronization multiplexer (SYNC MUX) 64 , where a preamble 66 is inserted into the stream at appropriate intervals. Preamble 66 is a known code which helps receivers 24 obtain synchronization and determine the timing of frames 30 and time slots 32 ( FIG. 2 ). The resulting TDMA-configured complex stream 42 serves as the output from TDMA modulation section 4 0 and feeds DSSS modulation section 44 . [0048] Within DSSS modulation section 44 , a demultiplexer (DEMUX) 68 divides TDMA-configured stream 42 of complex symbols 36 into blocks 34 ( FIG. 2 ) of symbols 36 . As a result, M unspread complex symbol substreams 70 are provided by demultiplexer 68 so that each unspread substream 70 contributes a single complex symbol 3 6 during each block 34 , and each block 34 has a block period T*M, where T is the symbol period of TDMA-configured stream 42 . [0049] Unspread substreams 70 feed a spreading section 72 . Within spreading section 72 , cyclic variations of common spreading code 38 ( FIG. 2 ) are applied to the M unspread substreams 7 0 to form M spread substreams 74 of “chips.” The chip period in each spread substream 74 is T*M/N. The M spread substreams 74 may be passed through an optional peak-to-average (P/A) reduction section 76 which adjusts phase angles of the complex chips conveyed in the spread substreams 74 in a manner understood by those skilled in the art to reduce peak-to-average power ratio and lessen demands placed on a power amplifier. Following P/A reduction section 76 , a combining section 78 combines spread substreams 74 to form composite signal 46 . Various embodiments of DSSS modulation section 44 are discussed in more detail below. [0050] Transmission section 48 includes any number of components and functions well known to those skilled in the art. For example, scrambling section 56 and/or synchronization multiplexer 64 , discussed above, may be included in transmission section 48 rather than in TDMA modulation section 40 . A pulse shaping section (not shown) is desirably included in transmission section 48 to spread the energy from each chip over a number of chip intervals using a suitable filter which minimizes inter-symbol or inter-chip interference so that spectral constraints may be observed. Transmission section 48 may also include digital-to-analog conversion, quadrature modulation, up-conversion, and power amplification functions, all implemented in conventional fashion. Power control may be implemented in transmission section 48 at the power amplifier to ameliorate a potential near-far problem, which should be much less pronounced in communication system 2 0 ( FIG. 1 ) than in traditional CDMA communication systems. After pulse shaping, analog conversion, up-conversion, and amplification, TDMA communication signal 2 6 is formed from composite signal 4 6 and wirelessly broadcast from transmission section 48 . Receiver 24 receives TDMA communication signal 26 . [0051] Within receiver 24 , communication signal 26 is processed through a receiving section 80 and passed to a code division multiplex (CDM) to time division multiplex (TDM) converter 82 . CDM to TDM converter 82 produces a baseband signal 84 , which is further demodulated in a TDM demodulation section 86 , with individual users receiving their respective data streams 88 . Of course, nothing requires a receiver 24 to serve multiple users and TDM demodulation section 86 may simply provide a data stream intended for a single user. [0052] Receiving section 80 includes any number of components and functions well known to those skilled in the art. For example, amplifying, filtering, and down-conversion may be performed to form an intermediate frequency (IF) signal. The IF signal may be converted from an analog form into a digital form, and automatic gain control (AGC) may be provided. In the preferred embodiments, the digitized form of the down-converted communication signal 2 6 passes to CDM to TDM converter 82 . [0053] Generally, CDM to TDM converter 82 performs despreading and optionally performs equalization on the communication signal. Various embodiments of CDM to TDM converter 82 are discussed in more detail below. [0054] TDM demodulation section 86 includes any number of components and functions well known to those skilled in the art. For example, channel estimation and synchronization may be performed in TDM demodulation section 82 . A rake receiver and/or equalizer may be included. De-interleaving, error correction decoding, and descrambling are desirably performed, and preambles and other control data are evaluated to detect time slots assigned to the receiver 24 . These and other components and functions conventionally used in digital demodulators may be included in TDM demodulation section 86 . [0055] FIG. 4 shows a timing diagram depicting how common spreading code 38 ( FIG. 2 ) is applied to blocks 34 ( FIG. 2 ) of unspread data substreams 70 ( FIG. 3 ) in accordance with first, second and third embodiments of DSSS modulation section 44 ( FIG. 3 ) in transmitter 22 ( FIG. 3 ). FIG. 4 is presented in tabular form, with rows representing the application of the chips of common spreading code 38 to symbols 36 ( FIG. 2 ). Columns in FIG. 4 depict successive blocks 34 . As indicated by a shaded region in FIG. 4 , spreading code 38 is applied to unspread substreams 70 so that composite signal 46 is influenced, at least for a portion of the time, by symbols 36 from two different blocks 34 . In particular, in the specific embodiment depicted by FIG. 4 , for only a single chip of each block period is composite signal 4 6 influenced by symbols 3 6 from a common block 34 of symbols. The manner of application of common spreading code 38 ( FIG. 2 ) to blocks 34 ( FIG. 2 ) of unspread data substreams 70 depicted in FIG. 4 may be contrasted with an alternate embodiment, discussed below in connection with FIG. 11 . [0056] FIG. 5 shows a block diagram of the first embodiment of DSSS modulation section 44 . Demultiplexer 68 is omitted from FIG. 5 for convenience. The unspread substream 70 conveying symbols a k,0 experiences no delay before being fed to a first input of a multiplier 90 . However, the unspread substreams 70 conveying symbols a k,1 through a k,M-1 are respectively delayed in delay elements 92 by 1 through M−1 symbol periods (T) before being fed to respective first inputs of other multipliers 90 . [0057] A spreading code generation section 94 generates cyclic variations of common spreading code 38 . FIG. 5 illustrates code generation section 94 in matrix form, which matrix takes on a cyclic Toeplitz form because the matrix elements hold cyclic variations of the same spreading code 38 . As depicted in FIG. 5 , different columns of the matrix supply code chips CO through CN−1 to second inputs of respective multipliers 90 . Different rows of the matrix indicate different code chips to apply during different chip intervals. So long as the number (N) of chips in spreading code 38 is greater than or equal to the number (M) of symbols 36 per block 34 , different code chips of the same code are applied to different symbols during any and all chip intervals. [0058] Outputs of multipliers 90 provide respective spread substreams 74 . FIG. 5 omits depiction of optional P/A reduction section 76 ( FIG. 3 ) for convenience. Combining section 78 takes the form of an adder, so that composite signal 4 6 during each chip interval equals the sum of M symbols 36 , with each of the M symbols being premultiplied by designated chips of common spreading code 38 . Accordingly, DSSS modulating section 44 temporally offsets application of common spreading code 38 to unspread substreams 70 so that the resulting spread substreams 74 correspond to unspread substreams 70 modulated by cyclic variations of common spreading code 38 . [0059] FIG. 6 shows a block diagram of the second embodiment of DSSS modulation section 44 . This second embodiment is equivalent to the first embodiment of FIG. 5 , but it is implemented differently. Demultiplexer 68 ( FIG. 3 ) is omitted from FIG. 6 for convenience. In this embodiment, spreading code generation section 94 need not be implemented as a two-dimensional matrix having a different row to define the different chips to be applied during different chip intervals, as discussed above in connection with FIG. 5 . Rather, spreading code generation section 94 may be implemented as a one-dimensional matrix having different columns, and only one of those columns is simultaneously applied to different unspread substreams 70 . Spreading code generation section 94 may be implemented as a shift register configured to shift cyclically at the chip rate. In order to achieve the appropriate temporal offsetting, delay elements 92 are now positioned between multipliers 90 and the adder of combining section 78 . Accordingly, in this second embodiment of DSSS modulating section 44 , DSSS modulating section 44 temporally offsets the application of common spreading code 38 to unspread substreams 70 so that the resulting spread substreams 74 correspond to unspread substreams 70 modulated by cyclic variations of common spreading code 38 . [0060] FIG. 7 shows a block diagram of the third embodiment of DSSS modulating section 44 . This third embodiment is also equivalent to the first embodiment of FIG. 5 , but is implemented differently. This third embodiment is a finite impulse response (FIR) implementation. In this third embodiment, symbol stream 42 ( FIG. 3 ) is fed to a series of delay elements 96 , each of which imparts a one-chip interval delay. The series of delay elements 96 serves the role of demultiplexer 68 ( FIG. 3 ) in this third embodiment, with the input to the first delay element 96 and the outputs of all delay elements 96 providing unspread substreams 70 . Delay elements 92 ( FIGS. 5-6 ) from the first and second embodiments of spreading section 72 are omitted. [0061] Spreading code generation section 94 simply provides common spreading code 38 , and need not be cycled because unspread substreams 70 to which spreading code 38 is applied are configured to perform the temporal offsetting requirements. Accordingly, symbol delay elements 92 are omitted and spreading code generating section 94 need not cycle the common spreading code or explicitly provide separate versions of spreading code 3 8 to separate unspread substreams 70 . Nevertheless, in this third embodiment of DSSS modulation section 44 , spreading section 72 temporally offsets application of common spreading code 3 8 by sequentially delaying symbols 36 to form unspread substreams 70 and applying spreading code 38 to the delayed symbols in unspread substreams 70 so that the resulting spread substreams 74 correspond to unspread substreams 70 modulated by cyclic variations of common spreading code 38 . [0062] FIG. 8 shows a first embodiment of CDM to TDM converter 82 included in receiver 24 ( FIGS. 1 and 3 ). Desirably, CDM to TDM converter 82 is configured to complement DSSS modulation section 44 of transmitter 22 ( FIGS. 1 and 3 ). In particular, this first embodiment of CDM to TDM converter 82 is configured to complement any of the first through third embodiments of DSSS modulation section 44 discussed above in connection with FIGS. 4-7 . [0063] CDM to TDM converter 82 includes a pulse shaping matched filter 98 , the output of which feeds a mismatched filter 100 . Pulse shaping matched filter 98 complements a pulse shaping filter (not shown) desirably implemented in transmission section 48 of transmitter 22 ( FIG. 3 ) to optimize signal-to-noise ratio and band-limit the signal. Pulse shaping matched filter 98 is desirably implemented using conventional techniques known to those skilled in the art. [0064] Mismatched filter 100 accomplishes two functions. One function is despreading and the other function is sidelobe suppression. In fact, mismatched filter 100 is desirably implemented to correspond to a spreader matched filter 102 upstream of a sidelobe suppression filter 104 . One technique for implementing mismatched filter 100 is simply to implement two filters coupled in series for the despreading and sidelobe suppression functions. In another technique (not shown) the two functions may be combined in a common filter. [0065] Mismatched filter 100 experiences a signal-to-noise ratio typically worse than that of a matched filter. However, in the preferred embodiments, mismatched filter 100 is desirably configured to achieve a relative efficiency of greater than 60%, and more preferably greater than 90%, compared to a matched filter. [0066] Those skilled in the art will appreciate that the configuration of common spreading code 3 8 is a strong determinant of the relative efficiency of mismatched filter 100 . For example, conventional orthogonal pseudonoise (PN) codes commonly used in conventional CDMA applications are unacceptable because their mismatched filters achieve relative efficiencies roughly around only 50%. [0067] While a wide variety of different codes may be used with the present invention, codes which have low aperiodic autocorrelation sidelobes and a substantially flat spectral analysis are preferred in this embodiment. Barker codes make suitable codes because of aperiodic autocorrelation sidelobes having magnitudes less than or equal to one. However, for many applications the limited length (i.e., N≦13) and/or prime numbered length of many Barker codes proves a detriment. In such cases, other codes having a greater length and slightly greater aperiodic autocorrelation sidelobes, such as magnitudes less than or equal to two or three are acceptable and may be easily derived by those skilled in the art. [0068] FIG. 9 shows an exemplary spectral analysis of a suitable spreading code usable in connection with the present invention. In particular, FIG. 9 represents an arbitrary code for which a spectral analysis can be performed using a time-frequency domain transformation, such as a Fourier transform. While a code having a precisely flat spectral analysis result is not a requirement, better results are achieved when no frequency bin shows substantially more or less signal level than other bins, as depicted in FIG. 9 . As an example, the signal level in each bin is desirably within ±25% of the average signal level taken over all bins. In particular, for best results no bins should exhibit a nearly zero signal level. [0069] The implementation of mismatched filter 100 illustrated in FIG. 8 will be readily understood by those skilled in the art. Spreader matched filter 102 may be implemented using the complex conjugate of spreading code 38 ( FIG. 2 ) presented in a reverse order. Sidelobe suppression filter 104 may be implemented using well-known FFT or linear programming techniques. [0070] The output of spreader matched filter 102 in mismatched filter 100 is a composite signal 106 equivalent to the autocorrelation function applied to each of the M unspread and spread substreams 70 and 74 (FIGS. 3 and 5 - 7 ) discussed above. [0071] FIG. 10 shows an exemplary timing diagram of the various individual signal components present in composite signal 106 output from the matched filter 102 portion of mismatched filter 100 . For convenience, FIG. 10 depicts an exemplary situation where the number of substreams 70 and 74 (i.e., M) equals seven and the number (i.e., N) of chips in spreading code 38 equals seven. Thus, each row in FIG. 10 represents one of the seven substreams, and each row depicts autocorrelation with an assumed rectangular pulse. Of course, composite signal 106 is the sum of all rows in FIG. 10 rather than seven distinct signals. [0072] Assuming ideal synchronization where samples are taken at the integral chip intervals of 0, 1, 2 . . . , then in this example, seven successive samples yield the signal levels of the seven substreams. However, each sample in composite signal 106 is corrupted by self-interference 108 , caused by sidelobes of the autocorrelation function. Accordingly, sidelobe suppression filter 104 ( FIG. 8 ) substantially attenuates the self-interference 108 of the sidelobes while not severely attenuating the autocorrelation peak. [0073] Referring back to FIGS. 3 and 8 , the output sidelobe suppression filter 104 provides baseband signal 84 , which also serves as the output of CDM to TDM converter 82 . Baseband signal 84 is routed to TDM demodulation section 86 . Depending upon the severity of multipath remaining in baseband signal 84 after processing through sidelobe suppression filter 104 , a rake receiver (not shown) or equalizer (not shown) may be used in TDM demodulation section 86 to compensate for the multipath. While some inefficiency may result from using a mismatched filter to despread communication signal 26 , any such inefficiency is more than compensated for by a marked improvement in multipath tolerance. [0074] While receiver 24 receives a communication signal 26 from one transmitter 22 , it may simultaneously receive other communication signals 26 from other transmitters 22 in adjacent radio coverage areas 2 8 ( FIG. 1 ). Conventional CDMA techniques may be used to prevent interference between such diverse communication signals 26 . For example, different spreading codes 38 may be selected for use at different transmitters 22 . Such different spreading codes 38 are desirably configured to have low cross-correlation sidelobes among all spreading codes 38 . If this option is selected, only a few (e.g., 3 - 7 ) of such codes need be used to prevent interference because interference should not be a problem between communication signals 26 from non-adjacent radio coverage areas 28 ( FIG. 1 ). Alternatively, transmitter 22 and receiver 24 may include other stages to further scramble/descramble spread spectrum signals using other spreading codes. [0075] The embodiments of the present invention discussed above and characterized by the timing depicted in FIG. 4 , wherein composite signal 46 is influenced, at least for a portion of the time, by symbols 3 6 from two different blocks 34 , show advantageous resilience in the presence of multipath. However, alternate embodiments, discussed below, may provide even better performance in the presence of multipath for some applications. [0076] FIG. 11 shows a timing diagram depicting how common spreading code 38 ( FIG. 2 ) is applied to blocks 34 ( FIG. 2 ) of unspread data substreams 70 ( FIG. 3 ) in accordance with fourth and fifth embodiments of DSSS modulation section 44 ( FIG. 3 ) in transmitter 22 ( FIG. 3 ). Like FIG. 4 discussed above, FIG. 11 is presented in tabular form, with rows representing the application of the chips of common spreading code 38 to symbols 36 ( FIG. 2 ). Columns in FIG. 11 depict successive blocks 34 . As indicated by a shaded region in FIG. 11 , spreading code 38 in the fourth and fifth embodiments is applied to unspread substreams 70 so that composite signal 46 is influenced, at all times, by symbols 36 from only common blocks 34 . [0077] FIG. 12 shows a block diagram of the fourth and fifth embodiments of DSSS modulation section 44 . Demultiplexer 68 ( FIG. 3 ) is omitted from FIG. 12 for convenience. In addition, in order to enable matrix multiplication operations discussed below, FIG. 12 represents that N symbols 36 (i.e. a k,0 through a k,N-1 ) are provided from demultiplexer 68 during each block 34 ( FIG. 2 ). In other words, FIG. 12 represents that the number (M) of symbols 36 per block 34 equals the number (N) of chips in spreading code 38 . Those skilled in the art will appreciate that when M<N, the number M of symbols 3 6 per block 34 may be made equal to N by padding with zeros so that the zeros are evenly distributed among the symbols 36 . As an example, if M equals 4 and N equals 12, then 12 symbols 36 may be provided by following each symbol 36 in each block 34 with two zeros. [0078] Unspread substreams 70 , which provide N symbols 3 6 per block 34 , pass to an optional time-frequency domain transformation section 110 . Time-frequency domain transformation section 110 may be implemented as an inverse fast Fourier transform (IFFT). For purposes of the present discussion, the fourth embodiment of DSSS modulation section 44 shall be deemed to omit section 110 , while the fifth embodiment shall be deemed to include section 110 . Thus, unspread substreams 70 convey time domain data to spreading section 72 in the fourth embodiment and frequency domain data to spreading section 72 in the fifth embodiment. [0079] While section 110 is not a requirement of the present invention, certain benefits may be achieved by the addition of section 110 as will be discussed below. Moreover, section 110 , or the equivalent, is conventionally included in digital communication transmitters which implement an orthogonal frequency division multiplexed (OFDM) modulation format. In such situations, section 110 may be present for use in connection with the present invention at little additional complexity or expense. [0080] Delay elements 92 ( FIGS. 5-6 ) are omitted in the fourth and fifth embodiments of DSSS modulation section 44 to permit only symbols 36 concurrently present during a common block 34 to influence composite signal 46 . However, spreading section 72 and spreading code generating section 94 are implemented in a manner similar to that discussed above in connection with the first and second embodiments of DSSS modulation section 44 ( FIGS. 5-6 ). In particular, cyclic variations of a single common spreading code 38 are applied in the form of a cyclic Toeplitz matrix (see FIG. 5 ). While spreading code generating section 94 acts to multiply the 1×N matrix of symbols 36 in each block 34 by spreading code 38 effectively in the form of an N×N cyclic Toeplitz matrix, it may do so simply through a one-dimensional matrix having different columns applied to different unspread substreams 70 at different multipliers 90 . Instead of selecting a spreading code 38 with low aperiodic autocorrelation sidelobes as discussed above in connection with the first, second and third embodiments of DSSS modulation section 44 , the fourth and fifth embodiments of DSSS modulation section 44 are better served with a spreading code 3 8 having low periodic autocorrelation sidelobes and a substantially flat spectrum. Spreading code generation section 94 may be implemented as a shift register configured to shift cyclically at the chip rate. Spread substreams 74 output from multipliers 90 are combined in an adding circuit 78 to form a pre-composite signal 46 ′, which is converted back into parallel streams at a demultiplexer (DEMUX) 112 into N chips per block 34 , labeled b k,0 through b k,N-1 in FIG. 12 . [0081] Demultiplexer 112 provides one technique for forming a cyclic prefix 114 . Chips b k,0 through b k,N-1 and cyclic prefix 114 are routed in parallel to inputs of a multiplexer (MUX) 116 for conversion into serial composite signal 46 . In particular, chips b k,0 through b k,N-1 are associated with an intended order, in which chips b k,0 , b k,1 , b k,2 , . . . b k,P occur first in pre-composite signal 46 ′, and chips b k,q , . . . b k,N-3 , b k,N-2 , b k,N-1 , occur last in pre-composite signal 46 ′. FIG. 12 illustrates an example where the p=2 first-occurring spread substreams in pre-composite signal 46 ′ are repeated as cyclic prefix 114 so that they also occur last in composite signal 46 . Of course, those skilled in the art will appreciate that the clock rate of multiplexer 116 is desirably sufficiently higher than the clock chip rate to accommodate cyclic prefix 114 . [0082] Transmission section 48 forms blocks 34 of communication signal 26 from blocks 34 of composite signal 46 . Blocks 34 of communication signal 26 propagate to receiver 24 through a communication channel, which may be unique to a specific transmitter 22 location and receiver 24 location. Blocks 34 of communication signal 26 experience multipath and other types of distortion when propagating through this channel. The mathematical effect of this distortion is equivalent to multiplying composite signal 46 by the transfer function of the channel, which imposes the multipath. [0083] As discussed above, each block 34 of composite signal 46 is formed from the matrix multiplication of the spreading code 38 with a block 34 of symbols 36 . The effect of multipath distortion is then the matrix multiplication of the matrix expression of the channel transfer function with this matrix product. Normally, a matrix multiplication does not observe a communicative mathematical property. In other words, the product of the channel transfer function by the spreading matrix does not necessarily equal the product of spreading matrix by the channel transfer function. [0084] Due to the failure of the mathematical communicative property in matrix multiplication, normally equalization to compensate for multipath should be performed before despreading in receiver 22 . Unfortunately, such equalization is exceedingly difficult to successfully perform, due at least in part to requiring the implementation of a filter with characteristics equivalent to the inverse of the channel transfer function. The characteristics of the channel cannot be easily controlled, and channel transfer function quite possibly has elements near zero. Attempting to form inverse filters of such characteristics often leads to unstable implementations. [0085] However, the use of cyclic variations of common spreading code 38 , when combined with cyclic prefix 114 and processed as discussed below in receiver 24 , enables the mathematical communicative property. Consequently, despreading may now occur prior to equalization for multipath, thereby making effective equalization a relatively simple task. [0086] FIG. 13 shows a second embodiment of CDM to TDM converter 82 for use with the fourth embodiment of the DSSS modulation section 44 (i.e., the time domain embodiment). The digitized IF form of communication signal 26 , after being distorted through the communication channel, is applied to a demultiplexer (DEMUX) 118 and a synchronization (SYNC) section 120 . An output of synchronization section 120 feeds a cyclic prefix removal section 122 of demultiplexer 118 . Synchronization section 120 identifies the start of blocks 34 , and cyclic prefix removal section 122 removes the first-occurring p chips from each block 34 . As discussed above, the last-occurring p chips duplicate the first-occurring p chips, and the last-occurring p chips and all other chips remain in each block 34 . The first-occurring p chips are removed because they are influenced by multipath from the previous block 34 of communication signal 26 . All chips, which remain in each block 34 , are influenced only by multipath from that block 34 . [0087] The block 34 of chips, with cyclic prefix 114 ( FIG. 12 ) removed, passes to mismatched filter 100 for despreading and equalization. As discussed above, due to the use of cyclic variations of spreading code 3 8 to spread symbols 3 6 and the inclusion of cyclic prefix 114 , the matrix multiplication which characterizes the channel now observes the communicative mathematical property. Consequently, despreading may occur before equalization. [0088] Despreading may take place using a despreading code generator 124 , a despreading section 126 , and a combining section 128 . Despreading code generator 124 , despreading section 126 , and combining section 128 are identical in structure to spreading code generator 94 , spreading section 72 , and combining section 78 in DSSS modulator section 44 of transmitter 22 ( FIG. 12 ), with the despreading code generated in despreading code generator 124 being related to spreading code 38 . In particular, despreading code chips D n =IFFT(1/FFT(C n )), where IFFT and FFT denote inverse fast Fourier transform and fast Fourier transform, respectively, and C n represents the chips of spreading code 38 . [0089] Spread substreams 130 are provided by demultiplexer 118 to multipliers 132 in despreading section 126 along with the despreading code matrix from despreading code generator 124 . The despreading code is applied in the form of a cyclic Toeplitz matrix due to the use of cyclic variations of a common spreading code to which the despreading code is related. Multipliers 132 provide despread substreams 134 to combiner 128 to add despread substreams 134 on a chip by chip basis into a serial pre-composite baseband signal 136 . Pre-composite baseband signal 136 is converted into parallel symbol substreams 140 at a demultiplexer (DEMUX) 13 8 , and symbol substreams 140 are applied to a maximum likelihood sequence estimation (MLSE) equalizer 142 or the equivalent. MLSE equalizer 142 may also be called a Viterbi equalizer. Parallel outputs from MLSE equalizer 142 feed a multiplexer (MUX) 144 which converts the parallel symbol substreams into baseband signal 84 for further processing by TDM demodulation section 86 ( FIG. 3 ). [0090] Those skilled in the art will appreciate that an MLSE equalizer is a simple structure, which is stable and can be effectively configured to compensate for multipath. The coupling of MLSE equalizer 142 downstream of despreading section 126 is possible due to the use of cyclic variations of common spreading code 38 in transmitter 22 and cyclic prefix 114 to enable matrix multiplication exhibiting the mathematical communicative property. [0091] FIG. 14 shows a third embodiment of CDM to TDM converter 82 for use with the fifth embodiment of DSSS modulation section 44 (i.e., the frequency domain embodiment), discussed above in connection with FIG. 12 . The digitized IF form of communication signal 26 , after being distorted through the communication channel, is applied to demultiplexer (DEMUX) 118 and synchronization (SYNC) section 120 , as discussed above in connection with FIG. 13 . Likewise, cyclic prefix 114 ( FIG. 12 ) is removed at cyclic prefix removal section 122 of demultiplexer 118 , as discussed above in connection with FIG. 13 . [0092] Spread substreams 13 0 are provided by demultiplexer 118 to a time-frequency domain transformation section 146 , which complements time-frequency domain transformation section 110 ( FIG. 12 ). Thus, if time-frequency domain transformation section 110 in DSSS modulation section 44 implements an inverse fast Fourier transform (IFFT), then time-frequency domain transformation section 146 desirably implements a fast Fourier transform (FFT). [0093] Mismatched filter 100 couples downstream of time-frequency domain transformation section 146 . In this third embodiment of CDM to TDM converter 82 mismatched filter 100 may be implemented in a manner that joins despreading and equalization functions in a common frequency domain equalizer. As illustrated in FIG. 14 , coefficients for the frequency domain equalizer take the form D* H(n) /D C(n) , where represents despreading code chips that are related to spreading code 38 in the manner discussed above in connection with FIG. 13 and D* H(n) represents the complex conjugate of the transfer function of the channel. One reason why a frequency domain equalizer is easy and effective to implement is that coefficients are not proportional to the inverse of the transfer function of the channel. While despreading code chips are related to the inverse of the FFT of the spreading code, such coefficients do not pose problems because the designer controls the FFT of the code through code selection, and a spreading code having a substantially flat spectral response may be selected, as discussed above in connection with FIG. 9 . [0094] Parallel outputs of mismatched filter 100 pass in parallel to hard decision sections 148 , and parallel outputs of hard decision sections 148 are combined into serial baseband signal 84 in multiplexer (MUX) 144 for further processing in TDM demodulation section 86 ( FIG. 3 ). [0095] Due to the enabling of the mathematical communicative property for matrix multiplication discussed above, mismatched filter 100 may reside downstream of time-frequency transformation section 146 , which improves the efficacy and simplicity of the equalization and despreading functions. [0096] The present invention provides an improved method and apparatus for wireless communications. The present invention contemplates the combination of TDMA and spread spectrum techniques so that wireless communications capacity is increased over the capacities achievable through conventional TDMA and/or CDMA systems using an equivalent amount of spectrum. Furthermore, robust, simple, and inexpensive processing techniques are usable in the present invention, making the present invention suitable for hubs, subscriber units, mobile stations, fixed stations, portable stations, and the like. The present invention may be adapted to and used in conjunction with a variety of modulation and multiple access techniques, such as frequency division multiple access (FDMA) and orthogonal frequency division multiplexing (OFDM). The advantages and improvements of the present invention are achieved, at least in part through the use of a composite RF communication signal which includes signal components obtained by modulating diverse branches of a single user's data stream using cyclic variants of a common spreading code. The present invention is configured to tolerate self-interference and is better able to tolerate multipath than conventional DSSS-CDMA communication systems. [0097] With reference to FIGS. 15 and 16 , additional embodiments of the present invention will now be described. The embodiments described below employ ultra-wideband communication technology. Referring to FIGS. 15 and 16 , ultra-wideband (UWB) communication technology employs discrete pulses of electromagnetic energy that are emitted at, for example, nanosecond or picosecond intervals (generally tens of picoseconds to hundreds of nanoseconds in duration). For this reason, ultra-wideband is often called “impulse radio.” That is, the UWB pulses may be transmitted without modulation onto a sine wave, or a sinusoidal carrier, in contrast with conventional carrier wave communication technology. Thus, UWB generally requires neither an assigned frequency nor a power amplifier. [0098] Another example of sinusoidal carrier wave communication technology is illustrated in FIG. 15 . IEEE 802.11a is a wireless local area network (LAN) protocol, which transmits a sinusoidal radio frequency signal at a 5 GHz center frequency, with a radio frequency spread of about 5 MHz. As defined herein, a carrier wave is an electromagnetic wave of a specified frequency and amplitude that is emitted by a radio transmitter in order to carry information. The 802.11 protocol is an example of a carrier wave communication technology. The carrier wave comprises a substantially continuous sinusoidal waveform having a specific narrow radio frequency (5 MHz) that has a duration that may range from seconds to minutes. [0099] In contrast, an ultra-wideband (UWB) pulse may have a 2.0 GHz center frequency, with a frequency spread of approximately 4 GHz, as shown in FIG. 16 , which illustrates two typical UWB pulses. FIG. 16 illustrates that the shorter the UWB pulse in time, the broader the spread of its frequency spectrum. This is because bandwidth is inversely proportional to the time duration of the pulse. A 600-picosecond UWB pulse can have about a 1.8 GHz center frequency, with a frequency spread of approximately 1.6 GHz and a 300-picosecond UWB pulse can have about a 3 GHz center frequency, with a frequency spread of approximately 3.2 GHz. Thus, UWB pulses generally do not operate within a specific frequency, as shown in FIG. 15 . In addition, either of the pulses shown in FIG. 16 may be frequency shifted, for example, by using heterodyning, to have essentially the same bandwidth but centered at any desired frequency. And because UWB pulses are spread across an extremely wide frequency range, UWB communication systems allow communications at very high data rates, such as 100 megabits per second or greater. [0100] Also, because the UWB pulses are spread across an extremely wide frequency range, the power sampled in, for example, a one megahertz bandwidth, is very low. For example, UWB pulses of one nano-second duration and one milliwatt average power (0 dBm) spreads the power over the entire one gigahertz frequency band occupied by the pulse. The resulting power density is thus 1 milliwatt divided by the 1,000 MHz pulse bandwidth, or 0.001 milliwatt per megahertz (−30 dBm/MHz). [0101] Generally, in the case of wireless communications, a multiplicity of UWB pulses may be transmitted at relatively low power density (milliwatts per megahertz). However, an alternative UWB communication system may transmit at a higher power density. For example, UWB pulses may be transmitted between 30 dBm to −50 dBm. [0102] Several different methods of ultra-wideband (UWB) communications have been proposed. For wireless UWB communications in the United States, all of these methods must meet the constraints recently established by the Federal Communications Commission (FCC) in their Report and Order issued Apr. 22, 2002 (ET Docket 98-153). Currently, the FCC is allowing limited UWB communications, but as UWB systems are deployed, and additional experience with this new technology is gained, the FCC may expand the use of UWB communication technology. It will be appreciated that the present invention may be applied to current forms of UWB communications, as well as to future variations and/or varieties of UWB communication technology. [0103] For example, the April 22 Report and Order requires that UWB pulses, or signals occupy greater than 20% fractional bandwidth or 500 megahertz, whichever is smaller. Fractional bandwidth is defined as 2 times the difference between the high and low 10 dB cutoff frequencies divided by the sum of the high and low 10 dB cutoff frequencies. However, these requirements for wireless UWB communications in the United States may change in the future. [0104] Communication standards committees associated with the International Institute of Electrical and Electronics Engineers (IEEE) are considering a number of ultra-wideband (UWB) wireless communication methods that meet the current constraints established by the FCC. One UWB communication method may transmit UWB pulses that occupy 500 MHz bands within the 7.5 GHz FCC allocation (from 3.1 GHz to 10.6 GHz). In one embodiment of this communication method, UWB pulses have about a 2-nanosecond duration, which corresponds to about a 500 MHz bandwidth. The center frequency of the UWB pulses can be varied to place them wherever desired within the 7.5 GHz allocation. In another embodiment of this communication method, an Inverse Fast Fourier Transform (IFFT) is performed on parallel data to produce 122 carriers, each approximately 4.125 MHz wide. In this embodiment, also known as Orthogonal Frequency Division Multiplexing (OFDM), the resultant UWB pulse, or signal is approximately 506 MHz wide, and has a 242 nanosecond duration. It meets the FCC rules for UWB communications because it is an aggregation of many relatively narrow band carriers rather than because of the duration of each pulse. [0105] Another UWB communication method being evaluated by the IEEE standards committees comprises transmitting discrete UWB pulses that occupy greater than 500 MHz of frequency spectrum. For example, in one embodiment of this communication method, UWB pulse durations may vary from 2 nanoseconds, which occupies about 500 MHz, to about 133 picoseconds, which occupies about 7.5 GHz of bandwidth. That is, a single UWB pulse may occupy substantially all of the entire allocation for communications (from 3.1 GHz to 10.6 GHz). [0106] Yet another UWB communication method being evaluated by the IEEE standards committees comprises transmitting a sequence of pulses that may be approximately 0.7 nanoseconds or less in duration, and at a chipping rate of approximately 1.4 giga pulses per second. The pulses are modulated using a Direct-Sequence modulation technique, and is called DS-UWB. Operation in two bands is contemplated, with one band is centered near 4 GHz with a 1.4 GHz wide signal, while the second band is centered near 8 GHz, with a 2.8 GHz wide UWB signal. Operation may occur at either or both of the UWB bands. Data rates between about 28 Megabits/second to as much as 1,320 Megabits/second are contemplated. [0107] Thus, described above are three different methods of wireless ultra-wideband (UWB) communication. It will be appreciated that the present invention may be employed using any one of the above-described methods, variants of the above methods, or other UWB communication methods yet to be developed. [0108] Certain features of the present invention may be employed by an ultra-wideband (UWB) communication system. For example, one embodiment of an UWB communication system divides a stream of data conveying symbols into a plurality of unspread substreams. A common spreading code is generated at the ultra-wideband transmitter, and each of the unspread substreams are spread using the common spreading code to form a plurality of spread substreams. The spread substreams are combined to form a composite signal that is transmitted using a plurality of discrete electromagnetic pulses. [0109] In another embodiment, an ultra-wideband communication system comprises a demultiplexer for dividing a stream of data conveying symbols into a plurality of unspread substreams. A spreading section is coupled to the demultiplexer and configured to generate a plurality of spread substreams from the plurality of unspread substreams. A combining section is coupled to the spreading section and configured to form a composite signal from the plurality of spread substreams, and a transmission section is coupled to the combining section and configured to transmit the composite signal over an ultra-wideband communication channel. [0110] The UWB devices, systems and/or methods in the above-described embodiments communicate with each other by transmitting and receiving a plurality of discrete electromagnetic pulses, as opposed to a substantially continuous carrier wave. Each pulse may have a duration that can range between about 10 picoseconds to about 1 microsecond, and a power that may range between about +30 dBm to about −60 dBm, as measured at a single frequency. [0111] The present invention may be employed in any type of network, be it wireless, wire, or a mix of wire media and wireless components. That is, a network may use both wire media, such as coaxial cable, and wireless devices, such as satellites, or cellular antennas. As defined herein, a network is a group of points or nodes connected by communication paths. The communication paths may use wires or they may be wireless. A network as defined herein can interconnect with other networks and contain sub-networks. A network as defined herein can be characterized in terms of a spatial distance, for example, such as a local area network (LAN), a personal area network (PAN), a metropolitan area network (MAN), a wide area network (WAN), and a wireless personal area network (WPAN), among others. A network as defined herein can also be characterized by the type of data transmission technology used by the network, such as, for example, a Transmission Control Protocol/Internet Protocol (TCP/IP) network, a Systems Network Architecture network, among others. A network as defined herein can also be characterized by whether it carries voice, data, or both kinds of signals. A network as defined herein may also be characterized by users of the network, such as, for example, users of a public switched telephone network (PSTN) or other type of public network, and private networks (such as within a single room or home), among others. A network as defined herein can also be characterized by the usual nature of its connections, for example, a dial-up network, a switched network, a dedicated network, and a non-switched network, among others. A network as defined herein can also be characterized by the types of physical links that it employs, for example, optical fiber, coaxial cable, a mix of both, unshielded twisted pair, and shielded twisted pair, among others. [0112] The present invention may be employed in any type of wireless network, such as a wireless PAN, LAN, MAN, or WAN. In addition, the present invention may be employed in wire media, as the present invention dramatically increases the bandwidth of conventional networks that employ wire media, such as hybrid fiber-coax cable networks, or CATV networks, yet it can be inexpensively deployed without extensive modification to the existing wire media network. [0113] Thus, it is seen that systems and methods of ultra-wideband communications are provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. For example, those skilled in the art will appreciate that the order of time-frequency domain transformation and spreading functions may be reversed from that shown in FIG. 12 . The specification and drawings are not intended to limit the exclusionary scope of this patent document. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well. That is, while the present invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those of ordinary skill in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims. The fact that a product, process or method exhibits differences from one or more of the above-described exemplary embodiments does not mean that the product or process is outside the scope (literal scope and/or other legally-recognized scope) of the following claims.

Systems and methods of ultra-wideband communication are provided. In one embodiment, an ultra-wideband communication system divides a stream of data conveying symbols into a plurality of unspread substreams. A common spreading code is generated at the ultra-wideband transmitter, and each of the unspread substreams are spread using the common spreading code to form a plurality of spread substreams. The spread substreams are combined to form a composite signal that is transmitted. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

RELATED APPLICATIONS [0001] This application claims the benefit of the filing date of a provisional application with Ser. No. 61/305,289 which was filed on Feb. 17, 2010, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD [0002] The disclosed subject matter is directed to the production of pre-cast blocks for constructing modular columns. BACKGROUND [0003] Decorative stone columns are widely used by homeowners and businesses for a variety of purposes such as the monuments at the entrance of a driveway, as supports between fence sections, as a base for a statue, and as pillars at the entrance to a building to name just a few uses. The construction of decorative stone columns normally requires the services of a skilled mason and the utilization of specialized masonry tools. The average individual does not typically have the necessary tools or requisite skill for constructing appropriate concrete forms or for completing decorative stone column construction. As a result, most decorative stone columns are usually constructed by a skilled mason and at a high cost. Producing a high quality, durable and aesthetically pleasing column at a reasonable cost can be accomplished with the assistance of modular column construction as is outlined below. SUMMARY [0004] The present invention pertains to the construction of a decorative column and the method of producing the modular blocks that comprise the decorative column. The column comprises a rigid center post surrounded by a plurality of modular blocks. Each modular block has a hole extending through it so the block can fit onto the rigid center post and remain fixed in place on the post. Each modular block is stackable upon another block of similar construction. The present invention pertains to a method for not only producing the modular blocks with compressible inserts but also the erecting of a decorative column that is capable of accommodating ground heaving due to freezing temperatures and thermal expansion which is particularly important, for example, when the column is utilized to support fence sections. [0005] The method comprises the steps of producing a flexible mold for forming the modular blocks, positioning a compressible insert into the mold, filling the open area created by the walls of the mold and the exterior surfaces of the compressible insert with a lightweight cementitious material, waiting for the cementitious material to cure and then removing the modular block from the flexible mold. [0006] Once the modular blocks with the compressible inserts are removed from the mold they are positioned onto the rigid center post so that the compressible insert center opening is aligned with the rigid post and can slide down the post to either the ground or atop another modular block. The process of placing the modular blocks on the center post can be repeated as necessary to produce a decorative column of the desired height. [0007] The compressible inserts are instrumental in reducing the weight of the modular blocks as the inserts are preferably comprised of materials such as EPS foam or cellular PVC to name but a few available options. In addition, the compressible inserts facilitate placement of the modular blocks on the rigid center post particularly for posts of a substantial height as the compressible and flexible material will not bind against the post as the blocks are lowered into position on the post. BRIEF DESCRIPTION OF DRAWINGS [0008] FIG. 1 is a perspective view of a three rail fence constructed with modular columns; [0009] FIG. 2 is a perspective view of a panel fence constructed with modular columns; [0010] FIG. 3 is a perspective view of a center post of a modular column being constructed with pre-cast ornamental blocks; [0011] FIG. 4 is a plan view of an embodiment of a pre-cast block without side slots utilized in a modular column; [0012] FIG. 5 is a plan view of an embodiment of a pre-cast block with single dimension side slots utilized in a modular column; [0013] FIG. 6 is a plan view of an embodiment of a block with dual dimension side slots utilized in a modular column; [0014] FIG. 7 is a plan view of an embodiment of a block with single dimension side slots utilized in a modular column; [0015] FIG. 8 is a cross sectional view of FIG. 2 revealing the interior features of a modular column; [0016] FIG. 9 is a perspective view of an empty mold with a center post for forming a block for use in a modular column; [0017] FIG. 10 is a perspective view of a mold showing a compressible insert surrounding the center post used for forming a block for use in a modular column; [0018] FIG. 11 is a perspective view of a mold showing the addition of a cementitious material to the open area of the mold for forming a block for use in a modular column; and [0019] FIG. 12 is a perspective view of a mold showing the cementitious material leveled at the top of the mold for purposes of forming a block for use in a decorative modular column. DETAILED DESCRIPTION [0020] Referring now to the drawings wherein like reference numerals refer to similar of identical parts throughout the several views. FIG. 1 reveals a fence section comprised of two modular columns 10 connected by fence rails 54 . FIG. 3 details the process by which a modular block 58 is lowered being lowered into position over a post 12 onto several pre-cast blocks 14 , 16 , 18 already in position. Pre-cast blocks can be used to efficiently and with high aesthetic appeal produce columns 10 for various embodiments of a rail fence such as seen in FIG. 1 as well as for various embodiments of a panel fence such as seen in FIG. 2 . Numerous other embodiments and uses of columns utilizing this modular pre-cast block technology are also contemplated and are only limited by the imagination. [0021] The production of a pre-cast block 58 begins with the use of a flexible mold 20 such as one produced from silicone and as depicted in FIG. 9 . The mold 20 includes four sides 22 A, B, C and D a center post 24 as well as textured interior walls 26 . The textured interior walls 26 are intended to replicate on the finished modular block a stone face including a desirable and contrasting coloration. Prior to the addition of any cementitious material into the mold 20 the textured interior walls are coated with a coloration mixture of mineral iron oxides, cement, water and an acrylic modifier. The coating is applied consistent with the stone facing molded into the interior walls 26 so as to give the impression that the stone faces are of varying color as might be created by a mason using natural stone. Varying the mineral iron oxides content allows different colors to be formulated to satisfy customer preferences. This coloration mixture may be hand applied to specified portions of the interior wall. Alternatively, automated techniques may also be employed such as the use of robotic systems to apply the coloration mixture. [0022] Once the subset of the textured interior walls 26 are coated with the above referenced mixture a compressible insert 28 is positioned over the center post 24 as shown in FIG. 10 . The compressible insert 28 is lightweight, and preferably comprised of materials such as EPS foam or cellular PVC. The insert 28 includes an upper surface 32 , and creates an interior space 33 that will prevent the intrusion of cementitious material and also includes a plurality of exterior walls 34 . The insert upper surface 32 is preferably at the same elevation and not above the upper surface 36 of the textured interior walls 26 . [0023] Once the compressible insert 28 is secured in position over the center post 24 , the open space 38 between the mold walls 26 and the exterior walls 34 of the compressible insert 28 is filled with a cementitious material 40 as seen in FIG. 11 . The cementitious material 40 is preferably a light weight wet cement that readily flows to fill the open space 38 . An exemplary mixture of cementitious material would comprise an expanded slate lightweight concrete, such as Stalite™, a dry pigment, aggregates and water combined to form a flowable, lightweight mixture. [0024] Once the open space 38 is completely filled the mold 20 is vibrated to remove voids from the cementitious material 40 , allow for settling and to facilitate the movement of the coloration mixture painted onto the mold interior walls 26 into the cementitious material 40 instead of remaining at the surface thereby giving a three dimensional penetration of the coloration mixture into the block and improving the weatherability of the block's surface coloration. In addition, as best seen in FIG. 12 , the cementitious material 40 is leveled at the upper surface 36 to create a smooth even surface that facilitates the stackability of the blocks when the cement is cured. [0025] In about twelve hours the cementitious material is fully cured and the block, along with the compressible insert, can be removed from the mold 20 . Manipulation of the flexible mold 20 , either manually by overturning the mold and popping out the block as is well known in the art, or by injection of air into an orifice in the mold bottom effectively inverting the silicone mold, will facilitate release of the block from the mold 20 . Because the cementitious material 40 permeates the pores of the exterior walls 34 of the compressible insert 28 , the insert is securely bound to the cementitious material and will not separate during use. [0026] As seen in FIGS. 4 through 7 , alternative embodiments of the block may be cast in the mold 20 with or without slots. FIG. 4 reveals a standard block 42 without slots that would properly be employed, for example, as shown at the lowermost block 18 in the column in FIG. 3 . This lowermost slotless block 18 would typically be employed in a column utilizing between one and four fence rails, such as exemplified in FIG. 1 . [0027] An alternative block embodiment as depicted in FIG. 5 reveals a block 50 with slots 52 on opposed sides of the compressible insert 28 . These opposing slots 52 serve to hold rails 54 in position as is best seen in FIG. 1 . FIG. 3 also serves to highlight how the slot 52 of block 58 integrates with the slot and block 14 positioned immediately below it in the column to create an opening for securing the rail 54 in position. It will be readily apparent to one versed in the construction of columns that the placement of the slots 52 in a modular block 10 may be offset by 90 degrees, instead of 180 degrees, should a block be needed for a corner column with fence rails extending outwardly at 90 degrees instead of 180 degrees. In addition, a block may have only a single slot 52 should a column be needed that is adjacent a building or other structure and the rails need only extend in a single direction. [0028] FIG. 6 depicts a third embodiment of a block 60 that is utilized in the construction of a panel fence such as that shown in FIG. 2 . The narrower and shorter slot 62 serves to secure in place the edge of the entire height of the fence panel 67 . The configuration of this slot 62 can also be viewed in cross section in FIG. 8 which shows four separate blocks 61 A, 61 B, 61 C and 61 D positioned at the top of the column. Block 61 A serves as a capping block and includes no slots since the fence panel does not extend upwardly to that height. Block 61 B includes an upper exterior surface 65 with no slot and a lower portion with a slot 64 . The slot 64 on block 61 B, in conjunction with slot 64 in block 61 C serves to secure one end of the upper rail 66 , as best seen in FIG. 2 , in position within the column. Block 61 C also includes a small slot 62 that is intended to facilitate securing the top portion of the panel 67 in position. Finally, block 61 D includes only a small slot 62 but no larger slot 64 , such as that depicted in FIG. 7 . The configuration of block 61 D is repeated on blocks lower in the column until reaching the lower rail 68 where a similar configuration of blocks is utilized to support the rail 68 and the panel 67 as seen at the top of the column with blocks 61 B and 61 C. The dimensions of the slots 62 , 64 may be tailored to any preferred dimension during production to suit the specific dimensions of the fence rails 66 , 68 and panels 67 that are being utilized. To produce slots of the desired dimension one or more inserts are positioned within the mold prior to introduction of the cementitious material 40 or the molds may have the inserts already included. Whether specifically designed into the mold for purpose of occluding the presence of the cementitious material or removable inserts are positioned within the mold 20 , once the cementitious material 40 has been cured the slots are formed into the finished block and they are ready for column construction. [0029] The various embodiments of the present invention may be utilized to create a structurally sound and aesthetically pleasing column that can stand alone or be incorporated into a fence of a wide range of configurations including rail fences or panel fences. The use of pre-cast blocks 58 with their aesthetically pleasing exterior surfaces, preconfigured slots and lightweight but structurally rigid material greatly facilitates the construction of the columns. Turning again to FIG. 3 , a rigid center post 12 is placed into the ground or secured by some other means so that it stands in a substantially vertical orientation. The center post 12 is preferably a vinyl composition post because of its resistance to weathering and insects, but may be of any sturdy material such as wood, metal or concrete. Additionally, the center post 12 can be of a wide range of dimensions such as 5 inches square or 3 inches square. Alternatively a rectangular of circular configuration for the rigid center post 12 also may be employed. The center post 12 must, however, be of only slightly lesser dimensions than the hole dimension of the compressible insert 28 so that proper alignment of the pre-cast blocks on the modular column 10 can be accomplished. [0030] As seen in FIG. 3 , once the center post 12 is secured in a substantially vertical orientation, the central opening 33 of the pre-cast block's 58 compressible insert 28 is aligned over the center post 12 . The first pre-cast block 18 to be installed is then moved onto the lowermost support surface which will either typically be a ground surface or a prepared level surface such as concrete. The process of placing additional pre-cast blocks on the column is greatly simplified with the use of a compressible insert 28 . The compressible insert material is soft and pliable and therefore will not bind against the center post 12 because of interference between the insert 28 and the post 12 . Moreover, as noted above, because of the light weight of the compressible insert and the fact that it occupies a significant percentage of the block interior volume that otherwise would be occupied by cementitious material 40 the pre-cast block weighs far less than a pre-cast block constructed without a compressible insert 28 . The nominal weight of a pre-cast block greatly facilitates the construction of a decorative modular column as placement of a pre-cast block with a compressible insert onto a center post 12 requires lesser physical exertion than installation of blocks comprised entirely of cementitious material 40 . [0031] As further seen in FIG. 3 , a multitude of modular blocks 14 , 16 , 18 , 58 may be placed onto the rigid center post 12 to create a decorative column of any desired height depending upon how the columns is to be employed, for example, as a fence post, a support column or a mailbox stand. If building a fence rail column then, as previously discussed, slots 52 , 62 , 64 may be configured to satisfy the dimensional requirements of the fence rails and panels. Advantageously, no mortar need be placed between the pre-cast blocks to secure them in position as the blocks simply reside one atop the other creating a seamless textured stone exterior along the entire length of the column. Also advantageously, the compressible insert 28 greatly facilitates the resiliency and longevity of the decorative column 12 in areas where there is heaving of the ground due to the freeze-thaw cycle. Because of these compressible inserts 28 , the pre-cast blocks can float on the center post 12 thereby avoiding the accumulation of tensile and compressive forces that can readily fracture hand crafted stone columns or even those with pre-cast blocks that are mortared and locked into fixed positions. For stone columns, such as those shown in FIG. 1 , that are employed as fence columns, the thermal expansion of the fencing segments can produce significant lateral loads on the stone columns that can be absorbed by the compressible inserts 28 thereby avoiding damage to the stone columns through cracking of the column materials. [0032] Those skilled in the art appreciate that variations from the specified embodiments disclosed above are contemplated herein and that the described embodiments are not limiting. The description should not be restricted to the above embodiments, but should be measured by the following claims.

A decorative column comprising a rigid center post, a plurality of pre-cast pieces with each piece having a hole extending therethrough so the pre-cast piece slides onto the center post and remains in place on the center post. Each pre-cast piece being stacked upon another pre-cast piece, the pre-cast pieces being of a predefined shape, and a compressible center core liner filling a portion of the hole of the pre-cast piece. The compressible center core including a cutout shape consistent with the cross sectional shape of the rigid center post thereby allowing passage of the center post through the compressible center core.