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This is a divisional application of application Ser. No. 786,898, filed on Oct. 11, 1985, now U.S. Pat. No. 4,778,557. BACKGROUND OF THE INVENTION This invention relates generally to laminate films and more specifically to laminate films in which individual layers of the laminate are bonded together by means of corona discharge treatment. This invention also relates to an apparatus for producing a multilayer laminate utilizing corona discharge treatment, and a method for producing such a laminate. The use of corona discharge treatment is well known in connection with preparing polyolefin surfaces for printing inks, and for preparing laminated plastic films. Thick, oriented polyolefin sheets of for example about 10 mils or greater, have been virtually unknown because of the complexities of orienting materials this thick. While it is possible to use conventional laminating techniques for producing relatively thick polyolefin laminates, such a method is quite costly. The laminate could be passed through a single stage corona discharge treatment to rpoduce the thick laminate, but it has been observed that treatment level changes as dielectric material builds up in the laminate, and the permissible thickness of the resulting laminate is thereby limited. Of interest in U.S. Pat. No. 3,171,539 issued to Holbrook et al and showing the treatment of both sides of an irradiated, biaxially oriented polyethylene to ensure bonding when the upper surface of the polyethylene material is contacted with its lower surface. Also of interest is U.S. Pat. No. 3,575,793 issued to Paisley which discloses the use of a biaxially oriented polypropuylene layer which is corona bonded to a cellophane layer which has been coated with saran. Additional outside layers of polymeric material may be laminated or coated to the opposite surfaces of the polypropylene or the cellophane. A bond is formed between the corona treated surface of the polypropylene and the saran coating of the cellophane material. Of interest is Canadian Patent Specification 1472376 issued to Dawes et al and discussing corona treating of facing surfaces of various polymeric materials, including ethylene homopolymers and copolymers, polyamides, and ionomers, and coating these materials with polyvinylidene chloride. In one embodiment, polyhexamethylene adipamide is treated on both of its surfaces with corona discharge and sandwiched by outside layers of ethylene butylene copolymer. All of the materials of this embodiment are blown films. It is desirable to conveniently produce at relatively low cost, in a continuous fashion, a relatively thick laminate preferably containing one or more component layers of oriented materials, or a laminate in which all the layers are oriented. OBJECTS OF THE INVENTION It is, therefore, an object of the invention to provide a relatively thick laminate by the use of corona discharge treatment of each of the layers of the laminate. It is a further object of the present invention to provide such a laminate having one or more oriented layers. It is yet another object of the invention to provide a method for producing a relatively thick multilayer laminate comprising either the simultaneous or sequential treatment of layers of thermoplastic material, one or more of which may be oriented, with corona discharge to provide a thick laminate characterized by shrinkability and/or high strength, and in which adequate interlayer bonding is achieved by the use of corona discharge. It is a further object of the present invention to provide an apparatus for making a relatively thick multilayer lamiante, one or more layers of which may be oriented, which provides a relatively low cost and efficient means of producing such a laminate. DEFINITIONS The terms "corona discharge treatment", "corona treating" and the like as used herein refer to subjecting the surfaces of thermoplastic materials, such as polyolefins, to corona discharge, i.e. the ionization of a gas such as air in close proximity to a film surface, the ionization initiated by a high voltage passed through a nearby electrode, and causing oxidation and other changes to the film surface. The terms "acid- or acid anhydride-modified polymeric materials" and the like, as used herein, refer to materials suitable for use as adhesives and which preferably include a graft copolymer of a polyolefin, such as polyethylene, or ethylene-ester copolymer substrate and an unsaturated carboxylic acid or acid anhydride, blended with a polyolefin, such as polyethylene, or ethylene-ester copolymer. The term "heat set" and the like as used herein describes a process step involving orienting a film or film layer and thereafter raising the temperature of the film or film layer to near its orientation temperature in order to provide a film with little or no shrink characteristics. The term "linear low density polyethylene" as used herein refers to copolymers of ethylene with one or more eomonomers selected from C 4 to c 10 alpha olefins such as butene-1, octene, etc. in which the molecules of the copolymer comprise long changes with few, relatively short side chains, branches, or cross-linked structures. Linear low density polyethylenes as defined herein have a density usually in the range of from about 0.916 grams per cubic centimeter to about 0.925 grams per cubic centimeter. Density should be measured in accordance with ASTM D 1505-68. The term "ethylene vinyl acetate copolymer" as used herein refers to a copolymer formed from ethylene and vinyl acetate monomers wherein the ethylene derived units in the copolymer are present in major amounts, generally from about 60% to 98% by weight, and the vinyl acetate derived units in the copolymer are present in minor amounts, generally from 2% to 40% by weight. The term "relatively thick" as used herein describes the overall thickness of a laminate produced in accordance with the present invention. Although thicknesses of ten (10) mils or greater are generally contemplated, thicknesses somewhat less than ten mils may also be included in laminates characterized by the presence of one or more layers of oriented material, which laminates would be difficult or impossible to produce except by either conventional laminating techniques or by the practice of the present invention. SUMMARY OF THE INVENTION In accordance with the present invention, a method for making a relatively thick multilayer laminate comprises corona treating a first and second outer layer of a thermoplastic material on one surface thereof; corona treating at least one interior layer of a thermoplastic material on both surfaces thereof; and bringing the treated surfaces of the first and second outer layers, and the at least one interior layer, into respective contact with each other such that the untreated surfaces of the first and second outer layers form the outside surfaces of the resulting laminate. In another aspect of the present invention, a relatively thick multilayer laminate comprises a first or sealant layer; a second or barrier layer adhered to the first layer; a third layer adhered to the second or barrier layer, the third layer comprising a polymeric material which adds strength to the resulting laminate; and a fourth or sealant layer adhered to the third layer. In still another aspect of the present invention, an apparatus for making a multilayer laminate comprises a series of film feed means each film feed means providing a layer of thermoplastic material; means for supplying film from each of the feed means to a respective corona discharge station; corona discharge means for corona treating both sides of each layer representing an interior layer of the resulting laminate; corona discharge means for corona treating one side of a first and second layer representing outside layers of the resulting laminate; and gathering means for bringing the treated surfaces of the layers into respective contact with each other such that the treated surfaces of contiguous layers bond together, and the untreated surfaces of the first and second outer layers form the outside surfaces of the resulting laminate. BRIEF DESCRIPTION OF THE DRAWINGS Further details are given below with reference to the drawings wherein: FIG. 1 is a schematic view of a preferred embodiment of an apparatus for making a relatively thick multilayer laminate; and FIG. 2 is a schematic view of an alternate embodiment of an apparatus in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring specifically to the drawings, in FIG. 1 a schematic view of a preferred embodiment of an apparatus for making a relatively thick multilayer laminate is shown. Film feed rolls 12, 22, 34, and 46 hold films 10, 20, 32, and 44 respectively. In accordance with the practice of the present invention, each of films 10, 20, 32, and 44 are fed from their respective feed rolls and passed over a corresponding rubber insulated roll 14, 24, 36 and 48. As described further below, the terms "film" and "layer" are used interchangeably to describe individual components of the laminate. Either of two types of corona treatment may be employed. A bare electrode may be used in combination with an insulated roll, e.g. a rubber insulated roll. Alternatively, a glass electrode may be used in conjunction with a bar metal roll. In the description of the preferred embodiments, when rubber insulated rolls are described, these are used with bare electrodes. It should be understood, however, that this combination is interchangeable with bare metal rolls and glass electrodes. In an actual working example, both combinations were used in a single apparatus. One surface of the first or outer layer 10 is subjected to corona discharge aas it passes over rubber insulated roll 14, a corona unit or station 18 being located in close proximity to insulated roll 14. Likewise film 20, 32 and 44 are carried over insulated rolls 24, 36 and 48 respectively. One surface of film 20 is subjected to corona treatment as it passes over roll 24 in close proximity to corona unit 28. Similarly, one surface of film 32 is subjected to corona treatment as it passes over roll 36 in close proximity to corona unit 40. The second or outer layer 44 is passed over insulated roll 48 but is not subjected to corona treatment on the exposed surface of the film in order to provide an outer layer with an untreated outside surface in the resulting laminate. Referring back to the first or outer layer 10, of FIG. 1, after initial treatment at corona unit 18, the film 10 passes over a second insulated roll 16 but is not subjected to corona treatment on its second surface. This thereby provides a first or outer layer with an outside surface which has not been treated by corona discharge. This untreated outside surface will form one of the outside surfaces of the resulting laminate. Films 20 and 32, after initial treatment are fed over second insulating rolls 26 and 38 respectively, in close proximity to corona units 30 and 42 respectively, to treat the other surface of those films. Film 44 is passed over insulating rolls 50 in close proximity to corona unit 52 which treats the surface of the second or outer layer 44 which will subsequently bond to one of the treated surfaces of film 32. The four films of the preferred embodiment are fed substantially at the same time past the corona units and gathered at pinch rolls 54 and 56. These rolls are preferably heated to a temperature ranging between about 150° F. and 200° F., and more preferably at a temperature of about 175° F. The gathered films are also put under pressure of about 150 to 250 pounds per linear inch and more preferably about 200 pounds per linear inch. As the films are gathered at pinch rolls 54 and 56, respective contiguous corona treated surfaces of films 10, 20, 32, and 44 bond together. The corona bonded laminate 58 emerges from the pinch rolls 54 and 56 and is gathered on take-up roll 60. In an alternate embodiment, a multilayered laminate having several layers may be produced substantially as described above, but is produced in relative sequential fashion as shown in FIG. 2. Thus, film 110 is fed from film feed roll 112 over insulated roll 114 and passes in close proximity to a corona unit 118 where one surface of film 110 is coron treated. The film 110, now treated on one surface thereof, is fed around a press roll 116 onto a laminating drum 117. Film 120 is fed from film feed roll 122 and over insulated roll 124 where it receives corona treatment from corona unit 128. Film 120 is then passed over press roll 126 where the opposite surface of the film is subjected to corona treatment from corona unit 130. Film 120, having been treated on both of its surfaces, is then brough into contact with the treated surface of advancing film 110 on laminating drum 117 to bond films 110 and 120 together at their interface. Film 132 is fed from feed roll 134 and around insulated roll 136 where one surface of film 132 is treated by corona discharge from corona unit 140. Film 132 is then passed over press roll 138 where the other surface of film 132 is treated by corona unit 142, after which film 132 is bonded to film 120 as it is advanced along laminating drum 117. The now three layer laminate comprising films 110, 120 and 130 is advanced along laminating drum 173 in the direction of the arrow shown in FIG. 2. Film 144 is advanced from feed roll 146 and over insulated roll 148 and press roll 150, treated by corona discharge from corona units 152 and 154 respectively, and bonded to the three-layer laminate to create a four-layer laminate. The four-layer laminate is advanced further along the surface of laminating drum 117. Film 156, fed from feed roll 158, is corona treated on both of its surfaces by corona units 164 and 166 as it passes over insulated roll 160 and press roll 162 respectively. Film 156 is thereafter bonded to the advancing laminate. Film 168, advanced from feed roll 170, is corona treated by corona unit 176 as it passes over insulated roll 172 and by corona unit 178 as it passes around press roll 174. Film 168 is therefter bonded to the advancing laminate along laminating drum 117. Finally, the second or outer layer 180 advances from feed roll 182 and is passed over insulating roll 184 and around press roll 186 where one surface of film 180 is subjected to corona treatment by corona unit 188. Film 180 thereafter is bonded to the advancing laminate and forms a second outer layer thereof. The total laminate consists of 7 film layers adhered together. The now constructed laminate is taken upon finished roll 190. This method has the advantage of providing better heat transfer to each of the 7 films laminated since press rolls 116, 126, 138, 150, 162, 174, and 186 can be individually heated. A wide range of polymeric materials is suitable for use in connection with the multi-stage laminator. A preferred laminate structure includes four layers of extruded films. This four-layer laminate was produced on the apparatus depicted in FIG. 1. Referring to that drawing, film feed roll 12 held a sealant layer 10 comprising a coextruded film having a first layer of linear low density polyethylene and a second layer of ethylene vinyl acetate copolymer (EVA). The EVA has a vinyl acetate content of about 4.5% by weight, and a melt index of about 10 grams/10 minutes to insure a very smooth surface. This sealant layer 10 was subjected to corona discharge along its EVA surface. At substantially the same time, a barrier layer 20 was fed from film feed roll 22 and corona treated on both surfaces thereof. Barrier layer 20 is a coextruded film having a first layer of EVA (4-1/2% vinyl acetate, melt index=10 gms/10 minutes); a second layer of EVA (17% vinyl acetate, melt index=3 gms/10 minutes); a third layer of cinylidene chloride/vinyl chloride copolymer (saran); a fourth layer of acid anhydride-modified EVA (CXA-162); a fifth layer of ethylene vinyl alcohol copolymer; a sixth layer as in the fourth layer; and a seventh layer of EVA (4-1/2% vinyl acetate, melt index=10 gms/10 minutes). A third layer 32 comprising oriented heat set polyethylene terephthalate, and a sealant layer 44 substantially identical to sealant layer 10 were also fed from film feed rolls 34 and 46 respectively. Third layer 32 could optionally be a nylon or other polymeric material which would add strength to the laminate, and was corona treated on both surfaces thereof. Fourth layer 44 was corona treated only on one surface. Fourth layer 44 included an ethylene vinyl acetate of 4-1/2% vinyl acetate content by weight, and a melt index of 10 gms/10 minutes; and an outer surface of linear low density polyethylene. The four layers 10, 20, 32, and 44 were gathered at pinch rolls 54 and 56, under heat (175° F.) and pressure (200 pounds per linear inch) to form a laminate of about 4 mils total thickness. It is emphasized that one or more, or all of the layers making up the laminate may be oriented. In a case where all or substantially all of the layers of a relatively thick, i.e., 10 mils or greater thickness laminate are oriented, a laminate results which is essentially unobtainable through coextrusion technology because of the difficulties of orienting very thick materials. The present invention also provides a more economical approach than the conventional laminating techniques well known in the art. An additional advantage of the present invention is the use of a multiple corona unit to avoid the dielectric material build-up which occurs when multiple passage through a single stage corona unit is used to produce a thick laminate material. Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be made without departing from the spirit and scope of the invention, such modifications and variations being readily made by those skilled in the art. For example, it is readily apparent that the number of film feed rolls utilized in connection with the invention may be varied depending on the number of layers of polymeric material making up the desired laminate. Onr or more film layers may optionally be irradiated. Accordingly, such modifications may be practiced within the scope of the following claims.
Discrete, self-supporting films are adhered together to form a unique laminate. The surface or outer self-supporting films comprise heat-sealable thermoplastic material, and one interior self-supporting film is adhered to one outer films and comprises an oxygen barrier material. An optional interior film may be adhered to the barrier film to add strength to the laminate. At least one of the films is oriented and the laminate has a thickness of at least about 10 mils. A preferred method of bonding or adhering the films together is by means of corona discharge treatment. The resulting film is characterized by shrinkability and high strength.
8
CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of application Ser. No. 343,239, filed Jan. 27, 1982, and now abandoned. TECHNICAL FIELD This invention relates to a process and apparatus for purifying recovery glass for recycling and reuse in the manufacture of hollow glass. Advantageously, the process permits the minimization of manual sorting by the use of a technique of mechanical purification carried out, in parallel, on separate granulometric portions of the recovery glass. BACKGROUND OF THE INVENTION The reuse of waste products is an important concern of many industries. In the hollow glass industry, the introduction of recovery cullet produced by the collection and grinding of bottles and other glass containers into molten glass charges for recycling represents a particularly desirable goal. Recycling operations, however, often present the risk of compromising manufacturing quality. In the glass industry, the fact that recovery glass does not have a uniform composition does not limit the proportion of cullet that can be incorporated into the molten glass charges. A major problem posed by the reuse of glass waste products containing a considerable proportion of foreign material, such as stones or infusible pieces of pottery, which is present due to collection processes and successive handling, is the possibility that an unacceptable percentage of foreign material will carry over into the new glass products and create deficiencies in the products of which they will ultimately become a component. To avoid this problem, the standard solution is to sort through the glass waste before reusing it. A further constraint on the process of purifying recovery glass is an economic one. It is not feasible to recover glass by sorting through household trash from normal collections, and glassmakers can only set up exclusive collection routes in exceptional cases. In order to secure sufficient tonnage for recovery, it is therefore necessary to arrange for special collection by the usual collection services for storage and, ultimately, routine delivery to the glassworks. Glass collected in this way, due to extensive handling and uncertain cleanliness conditions, contains many broken articles consisting of variable-sized fragments intermixed with light scrap materials such as packing trash, labels, papers, plastic cups, non-ferrous metal elements, lead, tin, and aluminum, or other impurities introduced during the intermediate storage stage, such as pieces or fragments of non-ferrous metals, stones or larger objects of various types. Even when direct collection processes are carried out under optimal conditions of cleanliness, the existence of various packaging elements for the original glass products makes it impossible to completely eliminate the presence of foreign materials in the collected used-products. Due to the presence of these impurities, the recovered raw glass materials must be purified. The most effective method of purification used to date has been the technique of manual sorting. This process has many drawbacks, including unpredictable results due to operator error and high costs due to the necessity of a series of successive treatments--whose yield of unwanted elements remains fairly constant while absolute effectiveness diminishes with each treatment--to attain a product having a somewhat acceptable level of impurities. DISCLOSURE OF THE INVENTION This invention discloses a process and apparatus for purifying recovery glasses for recycling and reuse. Objectives of the invention include the minimization of manual sorting of waste glasses and the improvement of yields of purified products resulting from manual sorting operations. According to one aspect of the invention, mechanical-purification-in-parallel process steps include the following: (a) separating the raw glass waste materials into several granulometric portions, (b) replacing manual sorting by performing selective grinding on each portion--making possible-- (c) separation, by screening of useful recoverable fractions having a low content of impurities from fractions to be rejected because they contain high proportions of refuse and no more than insignificant amounts of glass. This process permits the progressive elimination of all types of impurities, such as stones and infusible materials, and the incorporation of a large percentage of recovery cullet--up to about 50% and more--into the glass melt. According to a second aspect of the invention, at least four granulometric portions of the raw charge are advantageously separated: T1: fines, which require a special treatment T2: a lower middle portion T3: an upper middle portion T4: easily recoverable large fragments. After optional manual sorting, the middle portions undergo selective grinding, followed by screening into three fractions: a usable lower fraction an upper fraction, to be rejected a middle fraction, to undergo further treatment. Advantageously, the middle fraction of the upper portion is remixed with the lower middle portion before the latter is treated. This invention also discloses an apparatus for use of the above-described processes. The apparatus essentially comprises a grinder in combination with a two-stage screen. The selectivity of the screening step and the choice of limits of the sorting fractions are directly linked, as will later be shown, to the grinding conditions and, essentially, to the speed of the grinders, as well as to the residence time of the material in the grinders--the grinder output. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents a schematic view of a grinding and selective sorting installation according to the invention, with approximate distribution of tonnages expressed in percent and the relative content of impurities expressed per thousand. FIG. 2 represents a schematic diagram of the operation of an installation of this invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the apparatus which is illustrated is designed to purify recovery glass for recycling and reuse. Raw waste material or charge, introduced by hopper 1, undergoes an initial screening to separate out whole bottles or other articles and large-sized pieces. This separation is advantageously carried out by a screen which comprises a grizzly 2, having diverging bars, which is impenetrable to elements having a minimum size above about 40 mm. The large pieces caught by grizzly 2 typically represent, at most, about 15% of the treated tonnage. Impurities are readily identified by visual inspection and may be eliminated at manual sorting station 3. Selective grinding, carried out in grinder 4, is followed by screening into the following two fractions at screen 5: F41, from 0 to 25 mm, usable F42, from 25 to 40 mm, to be rejected. Grinding is advantageously performed by a crusher or, more precisely, a jawed granulator and screening is effected by a vibrating screen. The balance of the raw material travels over a magnetic belt 6 where ferrous products are almost completely eliminated. The material is then sent to a screen 7 which comprises a sieve 7a, having a mesh size of approximately 10 mm and a sieve 7b, having a mesh size of about 5 mm. Fines T1, which measure less than 10 mm, and therefore go through sieve 7a, represent a little less than about 10% of the tonnage and have a glass content which is at least equal to that of the initial raw material. The fines are separated by sieve 7b into two separate fractions: F11, from 0 to 5 mm F12, from 5 to 10 mm. Both fractions are easily recoverable and are stored in hoppers 8 and 9 for periodic treatment. Fraction F11, which comprises a little less than 3% of the collected products is made usable by reduction to fines of less than about 2 mm in grinder 10. Fraction F12 represents approximately 7% of the collected products. The homogeneity of the fraction F12 particles and the relatively small amount of them to be treated permit visual sorting at sorting station 11 by means of an automatic sorting apparatus. The sorting apparatus eliminates almost all of the stones, as well as a considerable fraction of glass. Depending upon the waste material, approximately 90% of the glass can be recovered later by a second pass through the apparatus, without the reintroduction of an appreciable amount of stones into the cullet. A central section M, which could not pass through sieve 7a and which comprises pieces of between about 10 and 40 mm in their largest dimension, can represent up to about 80% of the tonnage. The central section contains a lower proportion of impurities that are detrimental to the melt, particularly stones and other infusible products, than that initially contained by the raw material. This section is divided by screening at screen 12 into several portions that are treated in parallel. Preferably, the section is divided into two portions--T2 and T3--respectively having granulometry limits (having geometric proportions in a ratio close to 2:1) of from about 10 to 20 mm and from 20 to 40 mm. The two portions--one at sorting station 13 and the other at sorting station 14--are each subjected to a visual analysis with manual sorting to remove infusibles and thus improve the output at each station. Lower middle portion T2 represents about 20% of the initial tonnage while upper middle portion T3, which is more heavily charged with impurities, particularly infusible products, represents less than about 60% of the initial tonnage. The work of the operators carrying out the visual checking and handsorting of the infusible fragments is approximately equal for each of the fractions and under these conditions, sorting of stones and infusible fragments from each fraction has a theoretical efficiency of greater than 70%. Each of the two middle portions is subsequently stored in a delivery-regulating hopper, hoppers 15 and 16 respectively, before undergoing selective grinding in one of two crushers 17 and 18. These are percussion or impact crushers which consist of a bladed rotor which throws the pieces of product to be crushed against a certain number of blades located crosswise on the inside of the crusher tank. In the crushers, grinding is carried out at a moderate rotational speed, with a suitable air gap--on the order of magnitude of the average dimension of the pieces to be ground. In general, the feed delivery to the crusher will be somewhat less than normal delivery to the crusher used by the manufacturer for routine purposes, for example, the grinding of ores. The middle portions are then each screened into three respective fractions at two-stage screens 19 and 20. For the upper middle portion--portion T3--the screening can lead to three fractions whose limits are also in a geometric proportion in a ratio close to 2:1, specifically: fraction F31, from 0 to 10 mm, which represents about a third of the initial tonnage and is directly usable, fraction F32, from 10 to 25 mm, representing a little more than 20% of the tonnage and whose granulometry and composition are approximately similar to those of the lower of the two middle portions, T2, fraction F33, from 25 to 40 mm, which represents only 1% of the initial tonnage but contains almost 35% of the impurities and, therefore, should be eliminated. Because of its size characteristics, fraction F32 must be sorted again. It is advantageously mixed with the lower middle portion--T2--and the mixture is then subjected to selective grinding followed by screening into three fractions. Since the tonnage to be treated in this second grinding is, therefore, somewhat smaller in volume than that undergoing the first grinding, it is possible to use two grinders of identical capacity. Advantageously, the limits of the fractions chosen correspond to a geometric progression on the order of about 1.51: fraction F21, from 0 to 10 mm, represents about 40% of the initial tonnage and is clean enough to be used directly, fraction F22, from 10 to 15 mm, represents only about 4% of the initial tonnage, as was the case for fraction F12, its homogeneity and the small amounts to be treated permits optical sorting at station 21 with an automatic sorting apparatus under the same conditions as at sorting station 11, fraction F23, from 15 to 25 mm, represents about 1% of the initial tonnage and contains up to 15% of the impurities and, therefore, should be eliminated. At the end of the treatment process, the various recovered fractions are regrouped and sent to a magnetic sorting apparatus 22 which eliminates any metal particles introduced by wear of the grinders. Throughout the treatment process, the selectivity of the screening and the number of portions to be divided out depend upon the operating conditions and, in particular, the quality of the grinding. Table I shows, for each of two granulometric portions, T2 (10 to 20 mm) and T3 (20 to 40 mm), three examples of the distribution of granulometries, as a function of the peripheral speeds of the rotors (in m/s on AP o -type grinder of the HAZEMAG company, used for a delivery of 2.5 t/h) and the air gap (in cm). For each of the portions, the operating conditions noted above correspond, respectively, to those of tests 22 and 32. Division into portions other than those noted above is possible but, with this type of raw products, they represent the optimal compromise of balancing and yield of the mechanical sorting. TABLE I__________________________________________________________________________GRINDING CONDITIONSGRANULOMETRIC DISTRIBUTION IN CUMULATED %(rounded values)PORTION10-20 TEST 21 TEST 22 TEST 23FRACTION speed: 17 m/s air gap: 1 cm speed: 12 m/s air gap: 1 cm speed 12 m/s air gap: 3 cmcumulated % glass stones nonferrous lights glass stones nonferrous lights glass stones nonferrous lights__________________________________________________________________________15-20 0.33 0 39 39 1 22 22 59 2 34 24 5010-15 4 31 72 72 9 59 76 70 10 64 71 80 8-10 11 68 89 89 24 82 92 73 29 83 93 903-8 54 100 100 100 72 100 100 99.9 74 100 100 1000.63-3 89 94 950.63 100 100 100__________________________________________________________________________PORTION20-40 TEST 31 TEST 32 TEST 33FRACTION speed: 12 m/s air gap: 1 cm speed: 8 m/s air gap: 1 cm speed: 8 m/s air gap: 5 cmcumulated % glass stones nonferrous lights glass stones nonferrous lights glass stones nonferrous lights__________________________________________________________________________30-40 0 0 2 40 0.15 27 10 31 0.2 13 20 4425-30 0.4 15 23 80 1 40 46 80 2 50 46 8420-25 1 26 49 88 4 57 64 95 7 60 70 9415-20 5 54 74 96 18 76 99 99 27 79 97 9810-15 17 72 84 97 40 89 99.9 100 48 87 98 99 8-10 36 84 88 99 60 95 95 993-8 77 98 99.9 100 87 100 90 1000.63-3 96 97 990.63 100 100 100__________________________________________________________________________ FIG. 2 illustrates how the constituents of the initial cullet are distributed in the example of FIG. 1, between the various fractions that are to be recovered or eliminated. These constituents are sorted, according to the process previously detailed, into five categories: 1--glass 2--infusibles 3--non-ferrous products 4--light products 5--ferrous products. In the FIG. 2 diagram, the distribution of the total tonnage and its breakdown into categories are indicated in the various boxes, in successive columns, 0 to 5, ranked in a constant order and summarized at the bottom of the table. Ferrous materials, which are eliminated at the beginning of the operation by supplementary magnetic sorting, appear only at the top of the diagram. The tonnages indicated correspond to a treatment of 25 tons of recovery glass. The tonnages and the glass content were calculated from measurements made on experimental samples in a pilot installation, corresponding to the treatment of two tons of product by using the HAZEMAG-type AP o crushers mentioned above. Table II summarizes the results of this treatment. TABLE II______________________________________Glass Recovered In The FractionTreated By Selective Grinding: 98%IMPURITIES without withELIMINATED manual sorting manual sorting______________________________________Infusibles 70% 92.5%Non-ferrous 85% 85%Lights 84% 84%Ferrous 100% 100%______________________________________ Table II clearly shows that this invention provides a mechanical sorting process characterized by a high degree of efficiency and reliability that could only be obtained in several stages, and by considerable manpower if a manual sorting technique were used. The use of this mechanical sorting process, alone, or in combination with a manual sorting process, permits the introduction of amounts of cullet that can exceed 50% of the waste material into the hollow glass melt, depending on the particular state of purity of and the method of collecting the recovered products. The process of this invention is not limited to the examples given. It is possible, without exceeding the scope of the invention, to add other various steps to the process. For example, after elimination of the fines and the large fragments, the central portion of the material could be divided into more than two portions which could be partially recycled to the lower portions after grinding. In cases where the proportion of cullet to be incorporated into the melt is relatively small, or if the raw starting products have come from carefully-made direct collection processes, the manual sorting steps preceding the selective grindings can be totally eliminated. Alternatively, it would be possible to limit any manual sorting stages to follow the selective grindings. Other possible embodiments of the invention would complete the magnetic sorting made at sorting station 6, treat the fines by aspiration of the light products or treat the two fractions F12 and F22 on the same automatic optical sorting apparatus, add fraction F42 into portion T3 in hopper 16. On the other hand it has been found that a better separation of fraction F23 is obtained if the upper deck of screen 19 has openings, made of slits disposed transversely to its slope about 10 mm wide and 25 mm long for instance.
This invention discloses a process and apparatus for purifying recovery glass for recycling and reuse. The necessity for manual sorting techniques is minimized due to the invention's unique process of mechanical purification, in parallel, carried out on separate granulometric portions of the recovery glass.
8
STATEMENT OF GOVERNMENT RIGHTS Certain of the subject matter of the present application was developed under Contract Number DE-FC-04-03AL67635 awarded by the Department of Energy. The U.S. government has certain rights in this invention. CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/786,059, filed on Mar. 24, 2006. The disclosure of the above application is incorporated herein by reference. FIELD The present disclosure relates to methods and systems for heating particulate filters. BACKGROUND The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. Diesel engines typically have higher efficiency than gasoline engines due to an increased compression ratio and a higher energy density of diesel fuel. A diesel combustion cycle produces particulates that are typically filtered from diesel exhaust gas by a particulate filter (PF) that is disposed in the exhaust stream. Over time, the PF becomes full and the trapped diesel particulates must be removed. During regeneration, the diesel particulates are burned within the PF. Conventional regeneration methods inject fuel into the exhaust stream after the main combustion event. The post-combustion injected fuel is combusted over one or more catalysts placed in the exhaust stream. The heat released during the fuel combustion on the catalysts increases the exhaust temperature, which burns the trapped soot particles in the PF. This approach, however, can result in higher temperature excursions than desired, which can be detrimental to exhaust system components including the PF. SUMMARY Accordingly, an exhaust system that processes exhaust generated by an engine is provided. The system includes: a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine; and a grid of electrically resistive material that is applied to an exterior upstream surface of the PF and that selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. In other features, a method of regenerating a particulate filter (PF) of an exhaust system is provided. The method includes: applying a grid of electrically resistive material to a front exterior surface of the PF; heating the grid by supplying current to the electrically resistive material; inducing combustion of particulates present on the front surface of the PF via the heated grid; and directing heat generated by combustion of the particulates into the PF to induce combustion of particulates within the PF. Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. DRAWINGS The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. FIG. 1 is a functional block diagram of a vehicle including a particulate filter. FIG. 2 is a cross-sectional view of a wall-flow monolith particulate filter. FIG. 3 includes perspective views of front faces of PFs illustrating various patterns of resistive paths. FIG. 4 is a perspective view of a front face of the PF and a heater insert. FIG. 5 is a cross-sectional view of a portion of the PF of FIG. 2 including a conductive coating. DETAILED DESCRIPTION The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, the term module refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. Referring now to FIG. 1 , an exemplary diesel engine system 10 is schematically illustrated in accordance with the present invention. It is appreciated that the diesel engine system 10 is merely exemplary in nature and that the particulate filter regeneration system described herein can be implemented in various engine systems implementing a particulate filter. Such engine systems may include, but are not limited to, gasoline direct injection engine systems and homogeneous charge compression ignition engine systems. For ease of the discussion, the disclosure will be discussed in the context of a diesel engine system. A turbocharged diesel engine system 10 includes an engine 12 that combusts an air and fuel mixture to produce drive torque. Air enters the system by passing through an air filter 14 . Air passes through the air filter 14 and is drawn into a turbocharger 18 . The turbocharger 18 compresses the fresh air entering the system 10 . The greater the compression of the air generally, the greater the output of the engine 12 . Compressed air then passes through an air cooler 20 before entering into an intake manifold 22 . Air within the intake manifold 22 is distributed into cylinders 26 . Although four cylinders 26 are illustrated, it is appreciated that the systems and methods of the present invention can be implemented in engines having a plurality of cylinders including, but not limited to, 2, 3, 4, 5, 6, 8, 10 and 12 cylinders. It is also appreciated that the systems and methods of the present invention can be implemented in a v-type cylinder configuration. Fuel is injected into the cylinders 26 by fuel injectors 28 . Heat from the compressed air ignites the air/fuel mixture. Combustion of the air/fuel mixture creates exhaust. Exhaust exits the cylinders 26 into the exhaust system. The exhaust system includes an exhaust manifold 30 , a diesel oxidation catalyst (DOC) 32 , and a particulate filter (PF) 34 . Optionally, an EGR valve (not shown) recirculates a portion of the exhaust back into the intake manifold 22 . The remainder of the exhaust is directed into the turbocharger 18 to drive a turbine. The turbine facilitates the compression of the fresh air received from the air filter 14 . Exhaust flows from the turbocharger 18 through the DOC 32 and the PF 34 . The DOC 32 oxidizes the exhaust based on the post combustion air/fuel ratio. The amount of oxidation increases the temperature of the exhaust. The PF 34 receives exhaust from the DOC 32 and filters any soot particulates present in the exhaust. A control module 44 controls the engine and PF regeneration based on various sensed information. More specifically, the control module 44 estimates loading of the PF 34 . When the estimated loading achieves a threshold level (e.g. 5 grams/liter of particulate matter) and the exhaust flow rate is within a desired range, current is controlled to the PF 34 via a power source 46 to initiate the regeneration process. The duration of the regeneration process varies based upon the amount of particulate matter within the PF 34 . It is anticipated, that the regeneration process can last between 4-6 minutes. Current is only applied, however, during an initial portion of the regeneration process. More specifically, the electric energy heats the face of the PF for a threshold period (e.g., 1-2 minutes). Exhaust passing through the front face is heated. The remainder of the regeneration process is achieved using the heat generated by combustion of particulate matter present near the heated face of the PF 34 or by the heated exhaust passing through the PF. With particular reference to FIG. 2 , the PF 34 is preferably a monolith particulate trap and includes alternating closed cells/channels 50 and opened cells/channels 52 . The cells/channels 50 , 52 are typically square cross-sections, running axially through the part. Walls 58 of the PF 34 are preferably comprised of a porous ceramic honeycomb wall of cordierite material. It is appreciated that any ceramic comb material is considered within the scope of the present invention. Adjacent channels are alternatively plugged at each end as shown at 56 . This forces the diesel aerosol through the porous substrate walls which act as a mechanical filter. Particulate matter is deposited within the closed channels 50 and exhaust exits through the opened channels 52 . Soot particles 59 flow into the PF 34 and are trapped therein. For regeneration purposes, a grid 64 including an electrically resistive material is attached to the front exterior surface referred to as the front face of the PF 34 . Current is supplied to the resistive material to generate thermal energy. It is appreciated that thick film heating technology may be used to attach the grid 64 to the PF 34 . For example, a heating material such as Silver or Nichrome may be coated then etched or applied with a mask to the front face of the PF 34 . In various other embodiments, the grid is composed of electrically resistive material such as stainless steel and attached to the PF using a ceramic adhesive. It is also appreciated that the resistive material may be applied in various single or multi-path patterns as shown in FIG. 3 . Segments of resistive material can be removed to generate the pathways. In various embodiments a perforated heater insert 70 as shown in FIG. 4 may be attached to the front face of the PF 34 . In any of the above mentioned embodiments, exhaust passing through the PF 34 carries thermal energy generated at the front face of the PF 34 a short distance down the channels 50 , 52 . The increased thermal energy ignites particulate matter present near the inlet of the PF 34 . The heat generated from the combustion of the particulates is then directed through the PF to induce combustion of the remaining particulates within the PF. With particular reference to FIG. 5 , a thermally conductive coating 72 can be additionally applied at the inlets 62 of the channels 50 , 52 . The coating 72 can extend a short distance down the opened ends of the closed channels 50 . In various embodiments, the conductive coating extends within an inch of the front face of the PF. The resistive material of the grid 64 contacts the conductive coating 72 . Thermal energy is transferred to the conductive coating 72 when electrical energy passes through the resistive material. Heat from the conductive coating 72 ignites particulate matter present near the inlet of the PF 34 . Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, while this disclosure has been described in connection with particular examples thereof, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and the following claims.
An exhaust system that processes exhaust generated by an engine is provided. The system includes: a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine; and a grid of electrically resistive material that is applied to an exterior upstream surface of the PF and that selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.
5
CROSS REFERENCE TO RELATED APPLICATIONS This U.S. National Stage of Patent Cooperation Treaty Application Serial No. PCT/CA2005/000705 filed May 6, 2005 claims the benefit of the filing date of prior filed, U.S. Provisional Application Ser. No. 60/568,267 filed on May 6, 2004. FIELD OF THE INVENTION The invention relates to methods and apparatus for automatic lubrication of machinery, particularly bearings, that have fittings thereon adapted to receive a quantity of grease or similar lubricant, and more specifically to methods and apparatus that involve a selectable scheduling of lubrication and the active transport of a lubricant, especially by a cam-pump device, that will then inject such lubricant through such fittings into particular machinery that has been connected thereto. BACKGROUND OF THE INVENTION Lubricators that utilize compressed air, compressed springs, motor driven jack screws, augers or a gas generating cartridge as a driving force to eject lubricant into a machine are known in the prior art. For example, U.S. Pat. No. 4,023,648 to Orlitzky et al. describes a lubricant applicator that electrolytically generates a gas as a driving means to force lubricant out of a chamber into a bearing fitting. U.S. Pat. No. 4,671,386 to Orlitzky describes an applicator in which the required pressure is delivered by a bellows. Automatic control of the lubricating process is shown in U.S. Pat. No. 6,408,985 to Orlitzky et al., which describes a programmable, electrical motor-driven lubricator that in different embodiments forces lubricant from a chamber by the operation of a gear-driven or lever-driven piston, or by a bellows. U.S. Pat. No. 5,732,794 to Orlitzky et al, describes an automated lubricator which is microprocessor controlled and can be programmed to deliver lubricant to a bearing or the like at selected intervals. Operation of the lubricator rests upon the use of a minor pressure imposed by a spring to force lubricant into the threads of an auger, so that rotation of the auger by a motor controlled by the microprocessor then dispenses the lubricant while at the same time providing a mixing action to the lubricant. There remains a need for portable lubricators capable of supplying a quantity of lubricant quickly, and capable of maintaining a controlled quantity of lubricant over a range of back pressures and ambient temperatures. In some devices, if the back pressure is too high, or the temperature is too low, substantial time may elapse before the lubricant reaches the machinery intended to be lubricated, such as a bearing, and the latter may then become starved for lubricant and suffer damage accordingly. In some gas generating cells, for example, it may take several days to overcome a line resistance of 15 psi before the lubricant actually reaches the point of lubrication. Conversely, under high temperature conditions there is the opposite danger of overlubricating which can also be damaging. SUMMARY OF THE INVENTION In various embodiments, the invention provides a lubricator comprising a housing defining a main lubricant chamber (or alternative means for containing a fluid lubricant). The lubricant chamber may be adapted to contain a fluid lubricant. The housing may have a lubricant outlet for discharging the lubricant from the lubricator. The lubricator may include a piston pump in fluid communication with the main lubricant chamber (or alternative means for pumping the lubricant in fluid communication with the main lubricant chamber). The piston pump may include a pump chamber adapted to receive lubricant from the main lubricant chamber. The lubricator may include a main chamber piston biased in the housing to urge the lubricant from the main lubricant chamber into the pump chamber. The piston pump may further include a pump piston adapted to be driven to discharge the lubricant from the pump chamber through a lubricant outlet in the housing. A check valve may be mounted on the lubricant outlet, to check the discharge of lubricant from the lubricator when the piston pump is not driven. The lubricator may include a motor for driving the piston pump (or alternative means for driving the piston pump). The motor may have a drive shaft adapted to rotate a swash plate to act as a cam to drive reciprocating motion of the pump piston in the pump chamber. The drive shaft may be in axial alignment with the piston, the swash plate being set obliquely on the drive shaft to revolve when the motor is activated to give reciprocating motion to the piston in a direction parallel to the drive shaft. The piston may be biased in the pump chamber against the swash plate, so that the swash plate rides on the piston. Electronic controls may be provided in some embodiments for regulating the activation of the motor to control the discharge of the lubricant from the lubricator (or alternative means for regulating the discharge of the lubricant from the lubricator). The electronic controls may include an input for setting the rate of discharge of the lubricant from the lubricator. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional drawing of a lubricator in vertical elevation. FIG. 2A shows a piston pump of the invention broken away in vertical cross section. FIG. 2B shows an alternate piston pump of the invention broken away in vertical cross section. FIG. 2C shows an alternate embodiment of a drive shaft swash plate assembly of the invention, broken away in vertical cross section. FIG. 2D shows an additional alternate embodiment of a drive shaft swash plate assembly of the invention, broken away in vertical cross section. FIG. 3 is a schematic diagram of one embodiment of a circuit on circuit board providing electronic controls for the lubricator of the invention. FIG. 4 is a cross-sectional drawing of an alternate lubricator in vertical elevation, showing multiple lubricant outlets, each comprising a pump element mounted to the pump housing end plate. FIG. 5 is a detailed illustration of one embodiment of a swash plate of the invention. DETAILED DESCRIPTION OF THE INVENTION In some aspects, the invention comprises a portable device for single point or multiple point lubrication that includes a container having an outlet to be connected to the lubricating system of the machinery; a cam-pump lubricant dispensing mechanism between the container and the outlet. In selected embodiments, such a device may be adapted to produce relatively high pressure using a relatively small DC powered motor using a relatively small current draw (e.g. 0.500 amperes at 6 volts DC for 1200 psi). Selected embodiments may be made to be customer refillable using ordinary grease guns. Exemplary embodiments are illustrated herein, and described below, on the understanding that alternative embodiments may be implemented in keeping with the general scope of the invention as claimed. FIG. 1 depicts in vertical elevation a cross-sectional drawing of a lubricator 10 constructed within a cylindrical, elongated chamber 12 . The lower portion of chamber 12 is generally V-shaped with a hollow interior, thus permitting placement therein of a quantity of grease or lubricant 14 . On the sides of the V-shaped portion there is installed on one side a pressure relief valve 16 , and typically on the opposite site thereof is a zirk or alamite fitting 18 through which lubricant 14 can be introduced into chamber 12 . In the region of lubricator 10 on the side of piston 26 opposite that part of chamber 12 that contains lubricant 14 , DC motor 46 attaches axially to limit switch actuator 73 , which attaches axially to central shaft 34 , which attaches axially to driving pump swash plate/cam 31 and provides the rotational movement of the same so as to rotate driving swash plate/cam 31 . (as hereafter described). Limit switch actuator 73 activates limit switch 72 once per revolution, providing a revolution counter to circuit board 50 . Power for DC motor 46 derives from battery pack 48 constructed of 4 1.5V alkaline batteries sold under the trade name of Energizer Titanium X91 or similar. The batteries are connected in series to provide a nominal 6VDC. The motor, battery pack and limit switch all connect to circuit board 50 via convenient plugs for ease of replacement. Using batteries of the type indicated in battery pack 48 , it is found that in normal operation a chamber 12 containing 125 cc of lubricant 14 can be emptied out two times before battery replacement becomes necessary, i.e. a single battery pack 48 will provide enough power to dispense 250 cc of lubricant. Battery pack 48 is disposed within lubricator 10 in motor housing 62 that extends basket-like on either side of DC motor 46 , and control of DC motor 46 is provided from circuit board 50 , which is conveniently located adjacent thereto. More specifically, circuit board 50 is square shaped and is attached to circuit board housing 74 , disposed so as the DIP switch array 78 is accessible through the opening covered by switchcap 76 . O-ring 75 maintains a tight seal between circuit board housing 74 and switchcap 76 . Circuit board housing 74 is located on the open end of motor housing 62 and held in place by an external toroidal locking rim 67 which threadably attaches to motor housing 62 . O-ring 68 maintains a tight seal between motor housing 62 and circuit board housing 74 . In the region of lubricator 10 which includes DC motor 46 , battery pack 48 and circuit board 50 , chamber 12 is extended outwardly by a circular rim 52 that has external threads 54 and inwardly therefrom a toroidal cavity 56 containing at the bottom thereof an O-ring 58 . Disposing inwardly from toroidal cavity 56 is a toroidal spring 60 , the lower surface of which abuts the upper surface of outer side wall 27 of piston 26 . Motor housing 62 also extends outwardly to the periphery of the interior of lubricator 10 so as to rest upon the upper surface of toroidal spring 60 and compress the same. The strength of toroidal spring 60 is preferably adapted to provide a downward force against piston 26 that will produce a pressure of about 7 psi against lubricant 14 , thereby providing a relatively mild pressure which suffices to force lubricant 14 into pump chamber 44 via pump housing lubricant holes 43 . As hereafter described, it is the downward action of piston pump 32 which actually forces lubricant 14 to be expelled from lubricator 10 , and not any pressure as such on the bulk of lubricant 14 . It may now be noted that motor housing 62 is held in the position aforesaid by an external, toroidal locking rim 66 which threadably attaches to circular rim 52 . Threaded into the bottom end of chamber 12 is an externally threaded pump housing 20 , typically of ½ inch size. The outlet of chamber 12 is externally threaded to ½ inch NPT. Threaded onto the outlet of chamber 12 is check valve assembly 22 , which has ½ inch NPT internal threads and an extension having ¼ inch exterior threads for convenient attachment to a grease fitting on a bearing or the like. Inserted into check valve assembly 22 is check ball 40 which is kept seated by spring 41 , which is kept in place by retainer 42 . Above lubricant 14 is piston 26 having a tubular upwardly extending outer side wall 27 which encircles the interior of chamber 12 , the external periphery of outer side wall 27 being in close contact with the interior surface of chamber 12 and having disposed therein a set of piston o-rings 28 for maintaining a tight seal thereto. Piston 26 is further adapted to accommodate about the central vertical axis thereof a toroidal piston cup seal 30 through the center of which passes a central shaft 34 . Piston cup seal 30 ensures a tight seal between central shaft 34 and piston 26 above lubricant 14 . Attached to central shaft 34 is driving pump swash plate/cam 31 which rides on driven pump piston 32 . Return spring 33 is located between pump housing 20 and pump piston 32 . (as hereinafter described). As shown in greater detail in FIG. 2A , pump housing 20 further comprises a set of holes 43 therein at points within the region of chamber 12 containing lubricant 14 , which permits passage of portions of lubricant 14 into the pump chamber 44 of pump housing 22 . Rotation of central shaft 34 rotates driving pump swash plate/cam 31 , which causes pump piston 32 to move downwards, compressing spring 33 and transporting such quantity of lubricant 14 that has entered the pump chamber 44 outwardly through pump chamber opening 45 . When the lubricant pressure in the pump chamber opening 45 has overcome the resistance of check ball spring 41 , then check ball 40 moves downward, allowing the lubricant 14 to pass by check ball 40 and into the grease fitting or grease line (not shown) to which check valve assembly 22 has been connected. When piston pump 32 reaches the bottom of its travel, spring 33 is compressed. As driving pump swash plate/cam 31 continues to rotate, spring 33 forces pump piston 32 to move upwards back to its starting location. As it moves upwards, a vacuum is created in pump chamber 44 . When pump piston 32 has cleared pump housing holes 45 , lubricant 14 enters pump chamber 44 . As pump piston 32 moves upward, the pressure in pump chamber 44 decreases, which allows check ball spring 41 to seal check ball 40 into check valve assembly 22 , which prevents grease from returning into pump chamber 44 from the grease fitting, Guide pin 39 travels in a longitudinal motion which prevents pump piston 32 from rotating. O-ring 38 maintains a tight seal between pump housing 20 and check valve assembly 22 . This action repeats itself under control of circuit board 50 . FIG. 2B shows the an alternate embodiment of the pump. In this embodiment, check ball 40 , spring 41 , and retainer 42 are moved from check valve assembly 22 and installed in the bottom of the pump housing 20 . The operation does not change. Check valve assembly 22 in this embodiment is an adapter with ½ inch NPT internal threads and an extension having ¼ inch exterior threads for convenient attachment to a grease fitting on a bearing or the like. FIG. 2C shows an alternate embodiment of the driving pump swash plate/cam 31 . This embodiment functions to limit the pressure generated by pump piston 32 . In this embodiment, all functions of lubricator 10 operate as herebefore described. The additional features of the embodiment of FIG. 2C operate as follows. As the pressure increases in pump chamber 44 , pump piston 32 requires more force when traveling in a downward action to compress lubricant 14 . When the pressure in pump chamber 44 reaches a specific value (maximum pressure), overpressure spring 37 will start to compress. The maximum pressure is determined by the resistance of spring 37 . When overpressure spring 37 compresses, driving pump swash plate/cam 31 will travel upward into central shaft 34 . Guide pin 36 travels in a longitudinal motion in guide pin slot 35 , which prevents driving pump swash plate/cam 31 from rotating or becoming disconnected from central shaft 34 . When driving pump swash plate/cam 31 travels upward into central shaft 34 , the downward travel of pump piston 32 is reduced, which reduces the pressure developed in pump chamber 44 . This embodiment may also be adapted to provide compensation for expansion or contraction of components due to temperature changes. FIG. 2D shows an alternate embodiment of the pump. In this embodiment, retainer 47 maintains the position of driving pump swash plate/cam 31 and accurately positions pump piston 32 in relation to the pump housing 20 . Limit switch actuator 73 is modified to allow central shaft 34 to float in/out of actuator 73 , its position determined by the location of the pump assembly 20 . This mechanism may be adapted to provide temperature compensation to maintain consistant pump output over a temperature range. As cylinder 10 stretches in the heat, pump assembly 20 will travel away from actuator 73 , creating a larger gap inside actuator 73 above central shaft 34 . As cylinder 10 compresses when it cools, pump assembly 20 will travel toward actuator 73 , decreasing the gap inside actuator 73 . In this way, pump piston 32 will always remain stable in relation to pump housing 20 . FIG. 4 shows an alternate embodiment of the lubricator. In this embodiment there are multiple lubricant outlets, each consisting of a pump element 174 mounted to the pump housing end plate 172 . For clarity, FIG. 4 shows only two pump elements, whereas in alternative embodiments there may be a plurality of pump elements of three or more. Threaded onto the outlet of chamber 12 is pump housing 170 . O-ring 38 ensures a tight seal between lubricator 10 and pump housing 170 . Pump housing end plate 172 is attached to the open end of pump housing 170 using threaded screws (or alternative fasteners). O-ring 177 ensures a tight seal between pump housing 170 and pump housing end plate 172 . Pump elements 174 are threaded, or otherwise attached, onto pump housing end plate 172 , Pump elements 174 may for example be selected from commercially available pump elements, comprising a spring loaded piston pump and a check valve. In the embodiment of FIG. 4 , attached axially to central shaft 34 is the progressive displacement auger 160 . Attached axially to progressive displacement auger 160 is swash plate/cam 162 , and attached axially to swash plate/cam 162 is swash plate locating pin 164 . The bottom end of swash plate locating pin 164 terminates in pump housing end plate 172 . In the embodiment of FIG. 4 , rotation of central shaft 34 rotates progressive displacement auger 160 which remixes and pushes lubricant 14 from chamber 12 into pump housing chamber 176 , creating a positive pressure in pump housing chamber 176 , helping to ensure that lubricant is available at all times to pump elements 174 . Rotation of central shaft 34 rotates swash plate/cam 162 , which causes pump elements 174 to compress. The compression of pump elements 174 transports lubricant outwardly from pump housing chamber 176 into the grease fitting or grease line (not shown) which is attached to the outlet of pump element 174 . Lubricant is introduced into pump housing chamber 176 and chamber 12 through zirk or alamite fitting 18 . FIG. 3 is a diagram of one embodiment of a circuit incorporated on circuit board 50 . Circuit 100 serves to control the times of dispensation of lubricant by lubricator 10 , i.e. the times of operation of DC motor 46 which causes rotation of central shaft 34 and hence disposition of lubricant as previously described. Since particular embodiments of the invention may be placed in applications that have a wide range of different conditions of back pressure, bearing demands and the like, circuit 100 includes provisions for varying the timing of such lubricant dispensation. Circuit 100 includes switch array 78 and switches 80 - 92 in schematic form. Switch array 78 includes terminals connecting to one side of each of switches 80 - 92 , said terminals on the switch array being respectively numbered 8 - 14 and in circuit 100 all are connected to ground. Circuit 100 further comprises resistor array 104 containing a set of thirteenth-nineteenth resistors 106 - 118 , each of which preferably has a resistance of about 1 MΩ. The sides of switches 80 - 92 opposite their previously noted terminals connecting to ground have external terminals that are numbered on switch array 78 as 7 , 6 , 5 , 4 , 3 , 2 , and 1 respectively, and connect therethrough to proximal ends of thirteenth-nineteenth resistors 106 - 118 , respectively. The distal ends of thirteenth-nineteenth resistors 106 - 118 are mutually interconnected and connect also to terminal 18 of microprocessor (MP) 102 , which constitutes the RC0 terminal thereof. Thirteenth-nineteenth resistors 106 - 118 provide a pull-up resistive network for the switch inputs to MP 102 . That is, in addition to the aforesaid connections to thirteenth-nineteenth resistors 106 - 118 , terminals 7 , 6 , 5 , 4 , 3 , 2 , and 1 , connect to MP 102 as shown in Table 1. TABLE 1 Array 78 7 6 5 4 3 2 1 MP 102 19 20 21 22 23 24 25 Input RC1 RC2 RC3 RC4 RC5 RC6 RC7 In Table 1, the first row represents the terminals of switch array 78 , the second row represents the terminals of MP 102 to which the terminals in the same column of the first row connect, and the third row gives the standard notation for the aforesaid input terminals of MP 102 . MP 102 is preferably an EPROM such as the PIC16C55A manufactured by Microchip Technology Inc., i.e., a known type that can easily be programmed by a person of ordinary skill in the art. The power for MP 102 is provided by a connection to the MCLR input (terminal 28 ) thereof to VDD (as produced in a separate circuit described hereinafter). An oscillator circuit for timing the operation of lubricator 10 is made up of crystal 120 which connects on either side thereof to ground through first and second capacitors 122 and 124 (each about 22 pf) and also on either side thereof to terminals 26 and 27 of MP 102 labeled as “OSC 2 ” and “OSC 1 ”. Crystal 120 is preferably of a low power consumption type, and operates at a frequency of about 32.768 kHz. The RA0 and RTCC connections of MP 102 which are respectively terminals 6 and 1 thereof connect through sixth resistor 126 and then third capacitor 128 to ground. The RA1 terminal of MP 102 (terminal 7 ) connects through seventh resistor 130 to that same third capacitor 128 and thence to ground, and similarly the RA3 terminal of MP 102 (terminal 9 ) connects through fifth resistor 132 through third capacitor 128 to ground. Seventh resistor is preferably a U.S. Sensors thermistor (e.g. of the type 105RG1K), the measured resistance (Rm) of which is used to sense the device temperature on the basis of which the operation of lubricator 10 can be terminated. Seventh resistor 130 constitutes a part of a capacitive charging circuit that also includes sixth resistor 126 , third capacitor 128 , and fifth resistor 132 . Sixth resistor 126 has a small resistance of about 100Ω and serves to limit current through terminal 6 (RA0) of MP 102 . Through terminal 9 (RA3) of MP 102 a reference voltage Vr (e.g. VDD at 3.6 volts) is applied to fifth resistor 132 (Rc) so that third capacitor 128 (about 0.01 uf commences charging to a threshold voltage Vt (e.g. 2.5 volts), and a reference value Tc for the time of charging is stored in the MP 102 memory. Fifth resistor 132 will have a calibration resistance Rc of about 1 MΩ, but in any case Rc cannot exceed the resistance of seventh resistor 130 (i.e. the thermistor). After discharge of third capacitor 128 under the control of MP 102 , reference voltage Vr is applied to seventh resistor 130 and the charging time Tm in passing current through seventh resistor 130 is determined so as to yield the resistance value Rm thereof in accordance with the formula Rm=(Tm/Tc) Rc. On the basis of lookup tables stored in MP 102 , the temperature of seventh resistor 130 can be ascertained, or preferably the temperature dependant Rm value can be used to trigger a selected shut-off of circuit 100 . MP 102 is thus programmed by standard “burn-out” methods such that with the aforesaid resistance and capacitance values so selected, at a temperature of about −10 degrees Celsius seventh resistor 130 will have a resistance value Rm that will disable DC motor 46 run pin 15 (RB5) of MP 102 as discussed below. The further connections of MP 102 that serve to operate DC motor 46 are found at the RB5 terminal thereof (terminal 15 ) which connects through tenth resistor 134 (e.g. 27 kΩ) to the base of third BJ transistor 136 . The collector of third BJ transistor 136 connects to VCC. The emitter of third BJ transistor 136 connects through eleventh resistor 144 (e.g. 100Ω) to the base of forth BJ transistor 140 , while the emitter of forth BJ transistor 140 connects to ground directly. First resistor 150 (e.g. 1 KΩ) connects between Vcc and the collector of BJ transistor 146 of the 2N3904 type and serves as a pull-up resistor. The base of BJ transistor 146 is connected to terminal 17 (RB7) of MP 102 through eighth resistor 145 (e.g. 27KΩ). The emitter of BJ transistor 146 connects to green LED 138 which is connected to ground. Second resistor 149 (e.g. 1KΩ) connects between Vcc and the collector of BJ transistor 148 of the 2N3904 type and serves as a pull-up resistor. The base of BJ transistor 148 is connected to terminal 16 (RB6) of MP 102 through ninth resistor 147 (e.g. 27KΩ). The emitter of BJ transistor 148 connects to red LED 139 which is connected to ground. Under MP 102 program control, the green and red LED's are used to indicate operation and status conditions of the lubricator 10 . Third resistor 133 (e.g. 10KΩ) connects between MP 102 terminal 13 (RB3), pin 2 of the rotation sensor plug and ground, and is a pull-down resistor. Terminal 14 (RB4) of MP 102 connects to pin 1 of the rotation sensor plug. Limit switch 72 is connected to circuit board 50 via the rotation sensor plug. Forth resistor 135 (e.g. 10KΩ) connects between MP 102 terminal 11 (RB1), terminal 12 (RB2), pin 2 of the empty sensor plug, pin 2 or the remote/serial plug, and ground, and is a pull-down resistor. Terminal 13 (RB3) of MP 102 connects to pin 1 of the empty sensor plug. Terminal 10 (RB0) of MP 102 connects to pin 1 of the remote/serial plug. The remote/serial plug and the empty sensor plugs are used for inputting the status of future signals to the MP 102 microprocessor. In operation, through the internal programming of MP 102 , turning on the MP 102 output RC0 (terminal 18 ) connects any of the switches 80 - 92 which are off to VDD. Any of the switches 80 - 92 which are on connect the input to MP 102 to ground, thereby making the status of switches 80 - 92 inputs to the particular lines of MP 102 (RC1-RC7). This permits an output to be generated on the MP 102 output line RB5 through tenth resistor 134 to the base connection of BJ transistor 136 , turning on BJ transistor 136 . As indicated in Table 2, the specific time periods of such output are in each case determined by the programming of MP 102 . Turning on third BJ transistor 136 will connect VCC to the base connection of fourth transistor 140 through eleventh resistor 144 . Turning on fourth BJ transistor 140 connects motor 46 between VCC and ground, hence DC motor 46 begins operating. Although there are specific time periods shown in Table 2 for emptying lubricator 10 of lubricant 14 , it will be understood that such time periods are arbitrary and can be programmed to have different values as the user of the present invention may desire. TABLE 2 Days to Switch Switch Switch Switch Switch Switch Empty 1 2 3 4 5 6 15 ON OFF OFF OFF OFF OFF 30 OFF ON OFF OFF OFF OFF 45 ON ON OFF OFF OFF OFF 60 OFF OFF ON OFF OFF OFF 75 ON OFF ON OFF OFF OFF 90 OFF ON ON OFF OFF OFF 105 ON ON ON OFF OFF OFF 120 OFF OFF OFF ON OFF OFF 135 ON OFF OFF ON OFF OFF 150 OFF ON OFF ON OFF OFF 165 ON ON OFF ON OFF OFF 180 OFF OFF ON ON OFF OFF 195 ON OFF ON ON OFF OFF 210 OFF ON ON ON OFF OFF 225 ON ON ON ON OFF OFF 240 OFF OFF OFF OFF ON OFF 255 ON OFF OFF OFF ON OFF 270 OFF ON OFF OFF ON OFF 285 ON ON OFF OFF ON OFF 300 OFF OFF ON OFF ON OFF 315 ON OFF ON OFF ON OFF 330 OFF ON ON OFF ON OFF 345 ON ON ON OFF ON OFF 360 OFF OFF OFF ON ON OFF 375 ON OFF OFF ON ON OFF 390 OFF ON OFF ON ON OFF 405 ON ON OFF ON ON OFF 420 OFF OFF ON ON ON OFF 435 ON OFF ON ON ON OFF 450 OFF ON ON ON ON OFF 465 ON ON ON ON ON OFF 480 OFF OFF OFF OFF OFF ON 495 ON OFF OFF OFF OFF ON 510 OFF ON OFF OFF OFF ON 525 ON ON OFF OFF OFF ON 540 OFF OFF ON OFF OFF ON 555 ON OFF ON OFF OFF ON 570 OFF ON ON OFF OFF ON 585 ON ON ON OFF OFF ON 600 OFF OFF OFF ON OFF ON 615 ON OFF OFF ON OFF ON 630 OFF ON OFF ON OFF ON 645 ON ON OFF ON OFF ON 660 OFF OFF ON ON OFF ON 675 ON OFF ON ON OFF ON 690 OFF ON ON ON OFF ON 705 ON ON ON ON OFF ON 720 OFF OFF OFF OFF ON ON Although various embodiments of the invention are disclosed herein, many adaptations and modifications may be made within the scope of the invention in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the invention in order to achieve the same result in substantially the same way. For example, the circuit board may utilize surface mount devices, one or more extra LED's to provide additional user information, different microprocessors, or alternate board shapes. Numeric ranges are inclusive of the numbers defining the range. The word “comprising” is used herein as an open-ended term, substantially equivalent to the phrase “including, but not limited to”, and the word “comprises” has a corresponding meaning. As used herein, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a thing” includes more than one such thing. Citation of references herein is not an admission that such references are prior art to the present invention. Any priority document(s) and all publications, including but not limited to patents and patent applications, cited in this specification are incorporated herein by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein and as though fully set forth herein. In particular the following documents are hereby incorporated by reference: U.S. Pat. Nos. 4,023,648; 4,671,386; 6,408,985; 5,732,794. The invention includes all embodiments and variations substantially as hereinbefore described and with reference to the examples and drawings.
In various embodiments, the invention provides a lubricator comprising a housing defining, a main lubricant chamber adapted to contain a fluid lubricant. A piston pump in fluid communication with the main lubricant chamber may be adapted to be driven to discharge the lubricant from a pump changer through a lubricant outlet in the housing. A check valve may be mounted on the lubricant outlet, to check the discharge of lubricant from the lubricator. The lubricator may include a motor having a drive shaft adapted to rotate a swash plate to act as a cam to drive reciprocating motion of the pump piston in the pump chamber. The drive shaft may be in axial alignment with the piston, the swash plate being set obliquely on the drive shaft to revolve when the motor is activated to give reciprocating motion to the piston in a direction parallel to the driven shaft. The piston may be biased in the pump chamber against the swash plate, so that the swash plate rides on the piston.
5
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of application Ser. No. 11/039,470, filed Jan. 19, 2005, the entire disclosure of which is hereby incorporated by reference. FIELD OF THE INVENTION [0002] The present invention relates to a radiographic apparatus which senses an image of radiation which has passed through an object and outputs the sensed image, and a control method and program thereof. BACKGROUND OF THE INVENTION [0003] When a certain kind of phosphor is irradiated with radiation (e.g., X-rays, α-rays, β-rays, γ-rays, electron beam, or UV rays), part of the radiation energy is accumulated in the phosphor. When the phosphor is irradiated with excitation light such visible light, it exhibits photostimulated luminescence accordance with the accumulated radiation energy, as is known. The phosphor having such a characteristic is called an accumulative phosphor (stimulable phosphor). [0004] Using this accumulative phosphor, radiographic image information of an object such as a human body is temporarily recorded on an accumulative phosphor sheet. The accumulative phosphor sheet is scanned by excitation light such as a laser beam and caused to emit stimulable light. The obtained stimulable light is photoelectrically read to obtain an image signal. [0005] Radiation image recording and read-pit apparatus has been proposed, which outputs the radiographic image of an object to a recording material such as a photosensitive material or a display device such as a CRT as a visible image on the basis of the image signal (e.g., Japanese Patent Laid-Open Nos. 55-12429 and 56-11395). [0006] In recent years, systems using a digital X-ray imaging apparatus which senses an X-ray image by using a semiconductor sensor have been developed. These systems are practically advantageous because an image can be recorded over a much wider radiation exposure range as compared to conventional radiographic systems using silver-halide photography. [0007] More specifically, X-rays in a very wide dynamic range are read by a photoelectric conversion means and converted into an electrical signal. By using this electrical signal, a radiographic image is output to a recording material such as a photosensitive material or a display device such as a CRT as a visible image. Accordingly, a radiographic image free from the influence of a variation in radiation exposure can be obtained. [0008] In the conventional film-screen system, if the transmitted X-ray dose is insufficient, sufficient blackening cannot be obtained on the film. If the transmitted X-ray dose is too large, the film blackens excessively. That is, an error film unsuitable for observation may be generated. Such an error film is called a reject. A reject occurs not only when the transmitted X-ray dose is too large or too small but also when the patient as the object has carelessly moved. [0009] Films with rejects are not used for diagnosis and are placed together in a storage unit such as a box. At the end of the month, the number of reject films in the storage unit is counted and used to totalize the number of used films. Although the number of reject films is counted in this work, they are not totalized for each reject reason or operator. [0010] In the digital X-ray imaging apparatus, even when a reject has occurred, the number of rejects cannot be counted unless, e.g., they are output to films. In addition, since the images of the rejects are not transferred to the image server, the record of rejects is not made. SUMMARY OF THE INVENTION [0011] The present invention has been made in consideration of the above-described problems, and has as its object to provide a radiographic apparatus which can easily confirm the reject reason of each radiographic image and provide information to efficiently suppress occurrence of rejects at the time of radiography, a control method and program thereof. [0012] According to the present invention, the foregoing object is attained by providing a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0013] reception means for receiving a reject reason when the sensed image of the object has a reject; and [0014] storage means for storing the reject reason received by the reception means in a storage medium. [0015] According to the present invention, the foregoing object is attained by providing a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0016] input means for inputting a reject reason when the sensed image of the object has a reject; and [0017] storage means for storing the reject reason input by the input means in a storage medium in correspondence with radiographic information containing at least the sensed image. [0018] In a preferred embodiment, the storage means stores the reject reason and the radiographic information in the storage medium for each operator of the radiographic apparatus. [0019] In a preferred embodiment, the radiographic information contains radiographic condition information of the sensed image. [0020] In a preferred embodiment, the radiographic information contains object information about the object corresponding to the sensed image. [0021] In a preferred embodiment, the apparatus further comprises display means for displaying a reject reason candidate for the sensed image. [0022] In a preferred embodiment, the display means displays an occurrence frequency for each reject reason. [0023] In a preferred embodiment, the display means displays the reject reason for each operator of the radiographic apparatus. [0024] In a preferred embodiment, the display means displays the reject reason for each radiographic condition of the sensed image. [0025] In a preferred embodiment, the display means displays the reject reason for each object information of the object corresponding to the sensed image. [0026] According to the present invention, the foregoing object is attained by providing a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0027] storage means for storing a reject reason of the sensed image of the object in correspondence with radiographic information containing at least the sensed image; and [0028] display means for displaying the reject reason of the sensed image stored by the storage means before radiographing a new object. [0029] In a preferred embodiment, the display means displays an occurrence frequency for each reject reason. [0030] In a preferred embodiment, the display means displays the reject reason for each operator of the radiographic apparatus. [0031] In a preferred embodiment, the display means displays the reject reason for each radiographic condition of the sensed image. [0032] In a preferred embodiment, the display means displays the reject reason for each object information of the object corresponding to the sensed image. [0033] According to the present invention, the foregoing object is attained by providing a control method of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0034] a reception step of receiving a reject reason when the sensed image of the object has a reject; and [0035] a storage step of storing the reject reason received in the reception step in a storage medium. [0036] According to the present invention, the foregoing object is attained by providing a control method of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0037] an input step of inputting a reject reason when the sensed image of the object has a reject; and [0038] a storage step of storing the reject reason input in the input step in a storage medium in correspondence with radiographic information containing at least the sensed image. [0039] According to the present invention, the foregoing object is attained by providing a control method of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0040] a storage step of storing a reject reason of the sensed image of the object in a storage medium in correspondence with radiographic information containing at least the sensed image; and [0041] a display step of displaying the reject reason of the sensed image stored in the storage medium before radiographing a new object. [0042] According to the present invention, the foregoing object is attained by providing a program which implements control of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0043] a program code for a reception step of receiving a reject reason when the sensed image of the object has a reject; and [0044] a program code for a storage step of storing the reject reason received in the reception step in a storage medium. [0045] According to the present invention, the foregoing object is attained by providing a program which implements control of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0046] a program code for an input step of inputting a reject reason when the sensed image of the object has a reject; and [0047] a program code for a storage step of storing the reject reason input in the input step in a storage medium in correspondence with radiographic information containing at least the sensed image. [0048] According to the present invention, the foregoing object is attained by providing a program which implements control of a radiographic apparatus which senses an image of radiation which has passed through an object and outputs a sensed image, comprising: [0049] a program code for a storage step of storing a reject reason of the sensed image of the object in a storage medium in correspondence with radiographic information containing at least the sensed image; and [0050] a program code for a display step of displaying the reject reason of the sensed image stored in the storage medium before radiographing a new object. [0051] Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0052] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [0053] FIG. 1 is a view showing an example of the system configuration of an X-ray imaging apparatus according to the embodiment of the present invention; [0054] FIG. 2 is a view showing an example of an operation window according to the embodiment of the present invention; [0055] FIG. 3 is a view showing an example of an image confirmation window according to the embodiment of the present invention; [0056] FIG. 4 is a view showing an example of a reject reason selection window according to the embodiment of the present invention; [0057] FIG. 5 is a view showing an example of a reject reason statistic display window according to the embodiment of the present invention; and [0058] FIG. 6 is a flowchart showing processing executed by the X-ray imaging apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0059] A preferred embodiment of the present invention will be described in detail in accordance with the accompanying drawings. [0060] FIG. 1 is a view showing an example of the system configuration of an X-ray imaging apparatus according to the embodiment of the present invention. [0061] Arrows in FIG. 1 indicate flows of information and commands. [0062] Referring to FIG. 1 , the X-ray imaging apparatus comprises a standing position sensor unit 101 , lying position sensor unit 102 , high-voltage generation unit 103 , X-ray tube 104 , system control unit 105 , and display unit (e.g., a CRT or LCD) 106 . [0063] Reference numeral 107 denotes network. The X-ray imaging apparatus is connected to an HIS (Hospital Information System)/RIS (Radiology Information System) server (not shown) or an image management server (not shown) on the network 107 through the network 107 . [0064] The HIS/RIS server functions as a database server which transmits radiographic condition information or object information related to radiography by the X-ray imaging apparatus to the X-ray imaging apparatus and manages radiography execution results by the X-ray imaging apparatus. [0065] The network 107 is a so-called communication network typically implemented by the Internet, LAN, WAN, telephone line, leased digital line, ATM, frame relay line, communication satellite channel, cable TV line, or data broadcast radio channel or a combination thereof. The network 107 only needs to be able to transmit/receive data. [0066] The system control unit 105 controls the radiographic sequence related to the standing position sensor unit 101 , lying position sensor unit 102 , high-voltage generation unit 103 , and X-ray imaging apparatus. The system control unit 105 has, e.g., the constituent elements of a general-purpose computer (e.g., a CPU, a memory (RAM or ROM), hard disk, external storage unit (CD-ROM drive or DVD-ROM/RAM drive), and network interface). [0067] The standing position sensor unit 101 and lying position sensor unit 102 A/D-convert charges corresponding to the dose of X-rays which have passed through an object S and transfer the charges to the system control unit 105 as an electronic image. The object S will be referred to as a patient hereinafter as needed. [0068] The display unit 106 displays a graphic user interface to make the operator execute an operation for setting related to the high-voltage generation unit 103 or X-ray imaging. In an operation window provided by the graphic user interface, object information containing the name, sex, and age of the patient (object S) and radiographic information containing a sensed image are displayed. [0069] An example of the operation window displayed on the display unit 106 will be described with reference to FIG. 2 . [0070] FIG. 2 is a view showing an example of the operation window according to the embodiment of the present invention. [0071] A touch panel including, e.g., a liquid crystal display and an analog resistive film touch sensor sheet is applied to the display unit 106 of this embodiment. The display unit 106 displays a sensed image in a sensed image region 202 . In the example shown in FIG. 2 , no sensed image is displayed because radiography is not done yet. If the object image is taken from the front and side in chest radiography, the sensed image of the chest front is obtained first and displayed in the sensed image region 202 . [0072] An object information display region 201 displays object information (patient information) received from an external device (e.g., HIS/RIS server). In the object information display region 201 , object information containing, e.g., the name, sex, age, and ID of the patient is displayed. [0073] A standing position sensor unit button 203 is pressed to switch the sensor to the standing position sensor unit 101 . A lying position sensor unit button 204 is pressed to switch the sensor to the lying position sensor unit 102 . When the standing position sensor unit button 203 is pressed, the sensor of the standing position sensor unit 101 is set in a ready state, and a radiography menu 205 (to be described later) changes to that for standing position radiography. On the other hand, when the lying position sensor unit button 204 is pressed, the sensor of the lying position sensor unit 102 is set in a ready state, and the radiography menu 205 (to be described later) changes to that for lying position radiography. [0074] The radiography menu 205 includes body part buttons to designate various kinds of radiography target body parts. In the example shown in FIG. 2 , the “Chest P→A” button is selected, i.e., the chest front image should be taken. When an arbitrary one of the body parts buttons on the radiography menu is pressed, a desired body part is selected. When a body part button is pressed, display in a reject reason display region 207 changes. [0075] An operator name display/selection region 206 displays an operator. The operator name display/selection region 206 is formed as, e.g., a pull-down menu. When an arbitrary operator is selected from the pull-down menu, the operator name can be changed. If the operator name is to be changed, a password input window to input a password is displayed to confirm whether it is an authentic operator. [0076] The reject reason display region 207 displays, e.g., reject reasons for sensed images in the past which a classified by the radiographic condition, body part, sex, age, and operator. In this example, the reject reasons are extracted on the basis of a category including “chest front” (body part), “male” (sex), and “adult” (age). The reject reasons such as an overdose/underdose and excessive/insufficient amount of respiration of the patient are displayed before radiography to call operator's attention to prevent any further reject. [0077] Reference numeral 208 denotes a radiographic condition display region. As the radiographic conditions, the tube voltage, tube current, exposure time, and radiographic distance are set in advance for each body part. When an arbitrary body part button is selected from the radiography menu 205 , the set values of corresponding radiographic conditions are displayed in the radiographic condition display region 208 . [0078] A statistic window transition button 209 is pressed for transition to a statistic window in which statistics are displayed in detail. The statistic window can display the reject reasons for, e.g., each operator. This will be described later in detail. [0079] An example of an image confirmation window displayed in the sensed image region 202 of the display unit 106 after radiography will be described next with reference to FIG. 3 . [0080] FIG. 3 is a view showing an example of the image confirmation window according to the embodiment of the present invention. [0081] A sensed image display region 301 displays a sensed image. When the operator confirms the sensed image, and the image has no problem, the sensed image is determined by pressing an OK button 302 and stored in, e.g., the hard disk in the system control unit 105 . On the other hand, if it is determined that there is a reject reason such as an underdose, overdose, or motion of the patient, the operator presses a reject button 303 . In this case, a reject reason selection window ( FIG. 4 ) is displayed to select a reject. [0082] A preceding image selection button 304 is used to select an image taken before the sensed image displayed in the sensed image display region 301 and display the selected image in the sensed image display region 301 . A succeeding image selection image 305 is used to select an image taken after the sensed image displayed in the sensed image display region 301 and display the selected image in the sensed image display region 301 . [0083] Even when the OK button 302 is temporarily pressed for sensed images at the time of radiography, the reject button 303 can appropriately be pressed again for a desired sensed image selected by using the image selection buttons. In addition, when the reject button 303 is pressed for a sensed image, and the operator is going to end radiography without selecting any reject reason in the reject reason selection window ( FIG. 4 ), a dialogue to call operator's attention to select a reject reason is displayed. [0084] An example of the reject reason selection window which is displayed to select a reject reason when the reject button 303 is pressed will be described next with reference to FIG. 4 . [0085] FIG. 4 is a view showing an example of a reject reason selection window according to the embodiment of the present invention. [0086] A reject reason selection menu 401 displays a plurality of kinds of reject reason candidates. The operator can input the final reject reason by selecting an arbitrary reject reason candidate. If no reject reason candidate is present in the reject reason selection menu 401 , a reject reason candidate can additionally be registered. Especially, additional registration of reject reason can be implemented by, e.g., inputting characters from the keyboard by using a dedicated text input box. [0087] An example of a reject reason statistic display window displayed in the reject reason display region 207 will be described next with reference to FIG. 5 . [0088] FIG. 5 is a view showing an example of a reject reason statistic display window according to the embodiment of the present invention. [0089] In the example shown in FIG. 2 , the reject reasons are classified by the radiographic condition, body part, sex, and age and displayed before radiography. In the example shown in FIG. 5 , the reject reasons are displayed for each operator. [0090] An operator name display/selection region 501 is formed as a pull-down menu to select an operator. The name of an operator of the X-ray imaging apparatus can arbitrarily be selected in this window. When all operators are selected, the statistic of reject reasons for all operators is displayed. [0091] A period selection region 502 includes a menu to set the statistic period as the range of statistic of reject reasons. A plurality of kinds of predetermined period units such as one month, three months, six months, and one year can be set as the statistic period. [0092] A date selection region 503 includes a menu to set the date of statistic compilation. [0093] A display method selection region 504 includes a menu to select the reject reason display method. In this example, the reject reasons are displayed in descending order of occurrence frequency. Recent reject images may be displayed sequentially as a log. Alternatively, reject reasons for all operators may be sorted in descending order of frequency and displayed. [0094] A print button 505 is pressed to print the reject reason statistic display window on printing paper sheet. [0095] In this example, the reject reason statistic display window is printed on a printing paper sheet. The statistic values displayed in the reject reason statistic display window may be output to the hard disk in the X-ray imaging apparatus or HIS/RIS server as, e.g., text data in the CSV (Comma Separate Value) format for each reject reason. [0096] An example of processing executed by the X-ray imaging apparatus according to this embodiment will be described next. [0097] FIG. 6 is a flowchart showing processing executed by the X-ray imaging apparatus according to the embodiment of the present invention. [0098] First, in step S 601 , an operator name is selected on the display unit 106 on the basis of the operator's operation in the operator name display/selection region 206 on the operation window ( FIG. 2 ). [0099] In step S 602 , after the operator name is selected, the password input window to input a password to confirm whether the operator is authentic is displayed to receive input of the password. [0100] In step S 603 , it is determined whether the password registered in the memory of the system control unit 105 in advance coincides with the password input in step S 602 . If the passwords coincide with each other (YES in step S 603 ), the flow advances to step S 604 . If the passwords do not coincide with each other (NO in step S 603 ), the flow returns to step S 602 to prompt re-input of the password. [0101] Password re-input may be limited to a predetermined number of times (e.g., three times). If the passwords do not coincide before re-input reaches the predetermined number of times, the processing may be ended determining the operation as password input by an inauthentic operator. [0102] In step S 604 , the system control unit 105 executes the radiography sequence of the patient (object S) on the basis of patient information or radiographic condition information received from the HIS/RIS server connected to the network 107 . [0103] In step S 605 , the standing position sensor unit 101 or lying position sensor unit 102 forms an electronic image on the basis of the dose of X-rays which have transmitted through the patient (object S). The image is processed by the system control unit 105 and displayed in the sensed image display region 301 . [0104] In step S 606 , the operator confirms the sensed image displayed in the sensed image display region 301 and determines whether the sensed image has a reject. The operator presses the reject button 303 or OK button 302 in accordance with the determination. [0105] For this reason, in step S 606 , the presence/absence of press of the reject button 303 or OK button 302 is determined. If the OK button 302 is pressed (NO in step S 606 ), the flow advances to step S 607 to output the sensed image to the HIS/RIS server through the network 107 . [0106] If the reject button 303 is pressed (YES in step S 606 ), the flow advances to step S 608 to display the reject reason display window ( FIG. 4 ) and receive selection of a reject reason by the operator. [0107] In step S 609 , the selected reject reason and radiographic information (operator, radiographic unit (standing position sensor unit 101 or lying position sensor unit 102 ), sensed body part, date of radiography, radiographic condition, sex, and age) are made to correspond to each other and stored in the hard disk or memory in the system control unit 105 . Since a reject has occurred, the flow returns to step S 604 to execute radiography again. [0108] In the arrangement shown in FIG. 6 , when it is determined in step S 606 that the reject button 303 is pressed, the reject reason selection window is displayed in step S 608 to make the operator select a reject reason. Instead, the reject reason selection window ( FIG. 4 ) may be displayed to make the operator select a reject reason after re-radiography is ended. In this arrangement, since the reject reason is selected after the end of re-radiography, the processing can be executed without interrupting the radiography. For this reason, the operation efficiency can be increased. [0109] The reject reason statistic display window shown in FIG. 5 is generated on the basis of the reject reasons and radiographic information stored in the hard disk or memory in the system control unit 105 , as a matter of course. [0110] In step S 609 , the reject reason and radiographic information are made to correspond to each other and stored in the hard disk or memory in the system control unit 105 . Instead, reject reasons may arbitrarily be classified by the operator, radiographic condition, or object in accordance with the application purpose or purpose and stored in the hard disk or memory in the system control unit 105 . [0111] As described above, according to this embodiment, the reject reason of a sensed image and corresponding radiographic information (e.g., the operator name) are classified and displayed. Accordingly, the operator can easily recognize the reject reason of the sensed image. [0112] In addition, when the reject reason is presented in advance before radiography, the operator can recognize hints for the radiographic operation. Accordingly, the variation in accuracy of radiography between operators can be minimized as much as possible. [0113] Note that the present invention can be applied to an apparatus comprising a single device or to system constituted by a plurality of devices. [0114] Furthermore, the invention can be implemented by supplying a software program, which implements the functions of the foregoing embodiments, directly or indirectly to a system or apparatus, reading the supplied program code with a computer of the system or apparatus, and then executing the program code. In this case, so long as the system or apparatus has the functions of the program, the mode of implementation need not rely upon a program. [0115] Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the claims of the present invention also cover a computer program for the purpose of implementing the functions of the present invention. [0116] In this case, so long as the system or apparatus has the functions of the program, the program may be executed in any form, such as an object code, a program executed by an interpreter, or scrip data supplied to an operating system. [0117] Example of storage media that can be used for supplying the program are a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, a non-volatile type memory card, a ROM, and a DVD (DVD-ROM and a DVD-R). [0118] As for the method of supplying the program, a client computer can be connected to a website on the Internet using a browser of the client computer, and the computer program of the present invention or an automatically-installable compressed file of the program can be downloaded to a recording medium such as a hard disk. Further, the program of the present invention can be supplied by dividing the program code constituting the program into a plurality of files and downloading the files from different websites. In other words, a WWW (World Wide Web) server that downloads, to multiple users, the program files that implement the functions of the present invention by computer is also covered by the claims of the present invention. [0119] It is also possible to encrypt and store the program of the present invention on a storage medium such as a CD-ROM, distribute the storage medium to users, allow users who meet certain requirements to download decryption key information from a website via the Internet, and allow these users to decrypt the encrypted program by using the key information, whereby the program is installed in the user computer. [0120] Besides the cases where the aforementioned functions according to the embodiments are implemented by executing the read program by computer, an operating system or the like running on the computer may perform all or a part of the actual processing so the functions of the foregoing embodiments can be implemented by this processing. [0121] Furthermore, after the program read from the storage medium is written to a function expansion board inserted into the computer or to a memory provided in a function expansion unit connected to the computer, a CPU or the like mounted on the function expansion board or function expansion unit performs all or a part of the actual processing so that the functions of the foregoing embodiments can be implemented by this processing. [0122] As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. CLAIM OF PRIORITY [0123] This application claims priority from Japanese Patent Application No. 2004-013106 filed on Jan. 21, 2004, the entire contents of which are hereby incorporated by reference herein.
A control apparatus comprising a memory storing a program, and one or more processors which, by executing the program, function as an acquisition unit configured to acquire a radiation image taken by a radiation detector, a display control unit configured to display the image on a display unit, and a storage unit configured to store reject information corresponding to the radiation image and operator information, wherein the display control unit to display, on the display unit, information related to the reject information and the operator information.
0
FIELD OF THE INVENTION The present invention relates to activation and binding of cellulose fibers and similar fibers by means of thermoplastic fibers and heat. The basic technique is described in more detail in U.S. application Ser. No. 073,525 filed July 15, 1987, now abandoned, which application is incorporated herein by reference. BACKGROUND OF INVENTION A hot air oven was previously used for heat treatment of a mixture of cellulose fibers and thermoplastic fibers to melt the thermoplastic fibers and produce a binding action. The thermoplastic fibers must be heated to their melting point during a certain time period in order for satisfactory binding to take place. Such a thru-air heater is disclosed in, e.g., Swedish Patent Specification No. 199,787. An alternative method for achieving the necessary heating is the use of heated rollers. The use of infrared radiation for activating nonwoven cellulosic materials has indeed been suggested previously, but no practical method or apparatus has been designed for this purpose except the method and apparatus described in the above-mentioned U.S. patent application No. 073,525, now abandoned. However, certain improvements to this method and apparatus are needed to more effectively control the path of the air flow and the amount of air passing through the nonwoven material. The present invention relates to a new method and a new apparatus that are specifically suitable for using the principles described in U.S. patent application No. 073,525, now abandoned. Many napkin machines include a so-called "tissue portion". According to the present invention, the tissue material in the napkin is unnecessary and that entire portion of the machine can be replaced by the present invention. In this case, the length of the complete napkin machine is not increased. It is always an object to decrease the web length in such machines, since as a rule, the material in the machine must be discarded when the machine is stopped. The shorter the machine, the less discarded material there will be. SUMMARY OF THE INVENTION Thus, the present invention relates to a method of binding a nonwoven material by means of a binding agent requiring heat for activation of the binding agent, especially binding of cellulose fibers with a thermoplastic material, whereby the material is heated by means of an infrared radiation (IR) source and surface burning of the irradiated material is prevented by a weak air flow passing through the material. According to the invention, the air flow passes through the material in an inclined path directed from the edge of the infrared radiation source and toward the center thereof, by means of inclined guide plates or partitions. Moreover, the entire amount of air through the material and the power supply to the infrared radiation sources are controlled by a control means, so that the amount of air is controlled in order to compensate for changes or variations in the surface temperature of the material having a short time duration, and the power supply is controlled in order to compensate for changes or variations having a long time duration. Preferably, the distance between each respective infrared radiation source and the material is also controlled by said control means in order to compensate for variations having a very long time duration. The invention also relates to an apparatus comprising inclined guide plates or partitions to guide the air flow passing through the material in an inclined path directed from the edge of the infrared radiation source and toward the center thereof. Preferably, each infrared radiation source is surrounded by two sidewalls so that a space is formed between each sidewall and the radiation source for passage of the inlet air. The cross-sectional areas of said spaces are together approximately equal to the cross-sectional area of the opposite suction channel. Alternatively, the cross-sectional area of the space positioned beyond the radiation source seen in the direction of movement of the material can be larger than the cross-sectional area of the space positioned before the radiation source. Preferably, the supply of air is adapted to be controlled by means of two speed-controlled fans, one at the inlet of the apparatus and one at the outlet of the apparatus. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in more detail below by means of a preferred embodiment of the invention and by reference to the drawings. Thus, FIG. 1 is a perspective view of an apparatus according to the invention. FIG. 2 is a cross-sectional view showing the principles according to the invention in connection with a vertical binding apparatus. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In FIG. 1, a binding apparatus according to the invention is shown in perspective. The apparatus comprises a stand (10) having four strong legs (11). In the stand (10), there are two cassettes (12) facing each other for enclosing the wire on which the nonwoven material has been formed. The distance between the cassettes is adjustable for adaptation to the actual thickness of the nonwoven material. The adjustment is performed by several hydraulic cylinders (13) and is carried out in such a manner that the material is not squeezed by the cassettes. Each cassette comprises several IR-radiation elements equally distributed along the length of the cassette. Between the IR-elements, there are spaces through which the cooling air can pass. The cooling air is controlled by means of partition walls or other suitable means so that the desired flow is achieved, as described in detail below in connection with FIG. 2. The air is supplied to each cassette through large tubes (14). Air distribution members may be arranged inside the cassette for equal distribution of the air over the entire width or cross-section of the cassette, as described in more detail below. The apparatus is provided with a safety system to shut off the apparatus as soon as there is a risk of fire. At the same time there is supplied an inert gas, such as halogen gas, whereby all risk of ignition is removed. Moreover, the two cassettes are separated so that the IR-elements are immediately removed from the nonwoven material. This safety device is fully automatically controlled by a fire detector of known type. The apparatus shown in FIG. 1 is of the horizontal type in which the nonwoven material is moving in its normal horizontal path. This apparatus is preferred when there is sufficient space for inserting said apparatus in the path without too much rebuilding. However, if there is no room for the apparatus if it is in a horizontal position, it is also possible to utilize the fact that industrial plants are often relatively high. In this case, the nonwoven material is conducted upwards in a U-shaped path, as is schematically shown in FIG. 2. The operation of the apparatus is, however, completely independent of horizontal or vertical orientation. In FIG. 2, the normal wire direction is shown by the arrow (21), i.e., the wire (22) runs horizontally to the right in FIG. 2. The nonwoven material on the wire is transferred to a first vertical wire (23) by means of a first suction roller (24) in a conventional manner. During said vertical movement, the nonwoven material is positioned between the two wires, i.e., said vertical wire (23) and a second wire (25), which encircles a lower middle roller (26) and an upper middle roller (27), which also operates as a suction roller. After passing over the upper suction roller (27), the nonwoven material is gripped by a third wire (28) and is then transferred to the original wire (22) by means of a lower suction roller (29). Between the two middle rollers (26) and (27), there are several IR-elements (30) and corresponding suction stations (31) arranged in a cassette. In the embodiment shown, the IR-elements are only positioned along the upward path of movement of the material, but similar stations can of course also be positioned along the downward path of movement. Said wires can be TEFLON®-coated glass fiber wires, controlled in a traditional manner. The IR-elements (30) are spaced apart from one another, said space forming a suction channel (32) for the suction station (31). FIG. 2 shows that the suction channel (32) is narrower than the corresponding IR-element. Between each IR-element (30) and the corresponding side wall (34), there is formed a space (33), through which the inlet air flows. The cross-sectional area of said space is approximately equal to half the cross-sectional area of the suction channel, in order to have approximately the same air resistance as achieved in the suction channel (32). It should be noted that the cooling air from the IR-elements is not used as cooling air for the nonwoven material, since it is too warm. Said cooling air for the IR-elements is exhausted to the surroundings through separate outlets, e.g., at the side edges of the IR-elements, as described in more detail below. The IR-elements are positioned on both sides of the material, which gives the most favorable temperature distribution in the material. It is of course also possible to position the IR-elements on only one side of the material. Each IR-element comprises one or several parallel radiation sources surrounded by reflectors (37) and is provided with a protective glass (38) of quartz on the side facing the nonwoven material. In the space between the quartz glass and the reflectors, input cooling air flows to the IR-elements by means of separate fans. The air flows over the surfaces inside the IR-element and passes out to the surroundings or to outlet channels at the ends of the elements, which possibly can extend outside the side edges of the wire. Consequently, the cooling air for the IR-elements has a circulation path of its own, but the inlet air may very well be taken from the complete inlet air or alternatively directly from the surroundings of the apparatus. The IR-elements can be positioned so that the distance to the web can be adjusted as a function of various operating parameters. The adjustment can be provided by means of adjustment screws (39), which possibly can be driven by an electric motor to provide automatic adjustment. In this way, the distance to the web and thus also the distance to the nonwoven material, can be adjusted so that a suitable surface temperature is achieved at the edge of the IR-element. Each IR-element is defined by two side walls (34) so that the above-mentioned space (33) is formed between the IR-element (30) and the corresponding side wall (34). The side wall is sealed on the side towards the wire with a suitable device, such as a rubber seal (35). As can be seen in FIG. 2, the air flow through the wire will take place along an inclined path directed from the edge of the IR-element and toward the middle or center thereof. With this arrangement it is possible to position the IR-elements more closely to each other, which is necessary in order to obtain sufficient heating. It may be suitable to use an inclined guide plate (36) for directing the air flow in the correct direction. By means of this inclined guide plate, a short-circuit of the air flow is prevented to a certain degree. The air flow is controlled by means of several speed regulated fans. It is preferred to use one fan at the inlet and one fan at the outlet. These fans ensure that the right amount of air is passed through the web. It is of great importance that the air is equally distributed over the entire width of the nonwoven material. This can be attained by means of several known devices. Thus, it is possible to use guide walls and baffles or channels for guiding the air. Moreover, the air can be fed into special transverse tubes provided with radial outlet openings distributed over the length of the tube and thus over the width of the material. These outlet openings have such a cross-sectional area and such a distribution that a uniform air distribution takes place. Preferably, such distribution tubes extend inside the space above each IR-element for supply of air. Similar tubes may be arranged in the outlet section. It may be desirable that a greater amount of air be passed through the web immediately behind an IR-element, since the cooling requirements are greatest at this position. This effect can be obtained by selecting the distance between the IR-element and the corresponding side wall (34) so that the distance behind the IR-element is greater than the distance in front of the element, seen in the direction of movement of the web. The object of the heating of the nonwoven material is to heat the thermoplastic fibers as much as possible so that they perform their binding action to the desired extent. A suitable temperature is empirically determined for each type of thermoplastic fiber. A suitable temperature is at least 150° C. However, the temperature must not exceed 190° C., at which temperature cellulose fibers are deleteriously affected by the heat. It is of course of great importance that the temperature gradient in the material is as small as possible in order to obtain uniform binding properties in the material. The IR-elements are of the type that product radiation having a short wave length that penetrates the material to a certain extent. However, most of the energy is still dissipated at the surface of the material. An air flow is passed through the material in order to counteract this energy concentration at the surface of the material. The air flow should be weak in order not to dislodge the cellulose fibers. The air flow cools the material and at the same time distributes the heat energy over the entire cross-section of the material. For the purpose of illustration, it is mentioned that the power consumption of the IR-elements is about 288 kW for a specific material speed of 1,200 kg/hour, about 240 kW for 1,000 kg/hour and about 192 kW for 750 kW/hour. The power consumption seems to be approximately linearly proportional to the specific material speed but essentially independent of the linear speed of the material (m/sec) and the thickness of the material. In order to be able to use as weak an air flow as possible, it is advisable to use air that is as cold as possible. Air at room temperature can be taken directly from the surroundings of the apparatus or outdoor air that has been filtered can be used. It is of course also possible to use air that has been cooled to a lower temperature. This air is heated relatively rapidly by the material and transports the energy accumulated in the material during its passage through the material. At the same time, the necessary cooling of the surface of the material is obtained. According to the present invention, the apparatus is controlled so that the power consumption of the IR-elements, as well as the amount of air passing through the nonwoven material, are controlled by a control device. The control device is preferably an electronic device, e.g., a microprocessor. Input signals to the control device are the present values (is-values) or the different operation variables of the apparatus, such as the power consumption of each IR-element, the amount of air used per time unit, speed of the inlet and outlet fans, etc. Moreover, input signals are supplied from temperature sensors positioned along the nonwoven material on the wire. The control device controls the power consumption of each IR-element and the speed of the fans according to a desired control algorithm. This control algorithm has properties such that the control of the amount of air has a short time constant while the control of the IR-elements has a long time constant. This means that a fortuitous increase in the surface temperature behind one of the IR-elements results in an increase in the amount of air to compensate for the increase in temperature. Only if the increase is lengthy does a decrease of the power supplied to the corresponding IR-element take place. The control means can also comprise a means for controlling the distance between the wire and the corresponding IR-element by means of the above-mentioned screw device (39). This adjustment means has the same time constant as the power consumption and can be used alternatively. It is also possible to let this control means have a still longer time constant. It is desirable to use as many temperature sensors as possible in order to control the operation accurately and safely. Thus, it would be desirable to use a first sensor at the site of the highest surface temperature immediately behind the IR-element when viewed in the direction of movement of the wire; a second sensor immediately in front of the IR-element where the temperature probably is lowest; and a third sensor at the other side opposite the IR-element. By means of these three sensors, monitoring will ensure that the surface temperature will not be too high and that the heat transport to the other surface of the material takes place to the desired extent for equal temperature distribution. In the embodiment shown having five IR-elements, 15 sensors are required. Since reliable sensors are very expensive, it will probably be necessary to decrease the number of sensors and instead allow the microprocessor to compute the different temperatures according to a suitable mathematical model. Such a model should be produced in an empirical manner for different apparatus constructions. In such as embodiment it is sufficient to use two sensors or pyrometers, one at the middle and one at the end of the wire. It is also possible to use cheaper and less reliable sensors at certain positions in order to lower the cost for the sensors. The control device also performs other suitable functions in the apparatus, such as controlling the operation and alerting when dangerous conditions are imminent, e.g., when an IR-elemment is positioned too close to the wire. The control device can also store suitable adjustment parameters for different operation situations, e.g., distances, power consumption and air flow for the most common types of cellulose materials and thicknesses. The invention has been described above by reference to preferred embodiments. A person skilled in the art realizes that such embodiments can be modified in many respects while still conforming to the principles of the invention. Such modifications are intended to be within the scope of the invention. The invention is limited only by the appended patent claims.
A method and apparatus are disclosed for binding a nonwoven material by means of a binding agent requiring heat for activation, particularly for binding cellulosic fibers with a thermoplastic material. The material is irradiated with an infrared radiation source, and surface burning of the irradiated material is prevented by passing a weak flow of air through the material. Inclined walls guide the air flow through the material in an inclined path directed from the edge of the infrared radiation source and towards the center thereof. Each infrared radiation source is surrounded by two side walls so that a space is formed between each side wall and the radiation source for the passage of the inlet air. The cross-sectional areas of these spaces are together approximately equal to the cross-sectional area of a suction channel positioned opposite the spaces. The air flow is controlled by means of two speed-regulated fans, one at the inlet and one at the outlet of the apparatus.
3
FIELD [0001] Embodiments usable within the scope of the present disclosure relate, generally, to drill string stabilizers configured within drill strings and used in earth boring operations, and in particular designs of stabilizers which reduce rotational drag and improve drilling fluid flow during operation. BACKGROUND OF THE INVENTION [0002] Drill string stabilizers are well-known in the field of oil and gas well drilling as a means to avoid unintentional destabilizing forces known to occur in drilling operations. Stabilizers are commonly used to reduce vibrations, sidetracking and other unwanted effects of drilling through geologic formations. The use of stabilizers, in addition, can aid in maintaining the orientation of the drill bit as well as the drill string during operation, reducing the possibility of drift. [0003] Stabilizers operate by making physical contact with the interior wall of the borehole. Typically, stabilizers are constructed with one or more ribs, ridges, blades, or gage pads which protrude from the main body of the tool. These protuberances are placed in physical contact with the borehole wall, thereby providing stability. Contact, however, is made at the cost of rotational drag forces created between the protuberances and the borehole wall. Being placed in direct contact with the walls of the borehole, stabilizer protuberances must be constructed of durable materials. When used to stabilize the drill string within the borehole, protuberances are typically constructed from or with wear resistant materials. Rotational drag forces created by the contact of the protuberances with the borehole wall can lead to damage or fouling of the stabilizer. Further, vibration caused by these rotational drag forces can lead to breakage of some other parts of the drill string. [0004] Stabilizers can be designed to hold the drill string in a fixed orientation or can be designed to allow orientational changes, such as are necessary in directional drilling. Variation of the length of the protuberances along the main body of the tool allows the drill string either to be held in a fixed position relative to direction, such as when longer protuberances are used, or to allow flexing of the drill string to allow orientation or reorientation of the drill string during directional drilling, such as when shorter protuberances are used. [0005] Moreover, stabilizers must be constructed so as not to obstruct the flow of drilling fluid, which is pumped into the borehole in part to cause the removal of pieces of rock cut away from the geologic formation by the drill bit, thereby cleaning the borehole. An interstitial area is commonly placed between the protuberances, through which the drilling fluid is circulated, carrying rock cuttings and other debris with the drilling fluid. Such an interstitial area between two protuberances known in the art would be generally of the same shape as the protuberances. That is, if the protuberances are straight, the interstitial area will be straight lithe protuberances are curviform, the interstitial area between them will be curviform. [0006] While stabilizers must, therefore, be designed to withstand the harsh conditions of the borehole during drilling operations, they must also be designed not to impede the flow of drilling fluid, which is equally necessary for effective drilling operations. Current stabilizer designs are typically seen either to contain large, straight protuberances, which allow the stabilizer to stand up against frictional forces, or stylized or curviform designs which reduce frictional forces but impede the flow of drilling fluid. [0007] Specifically, current stabilizer designs are generally seen to contain large, straight protuberances designed for soft formations and maximum fluid flow or bypass area or they contain spiral-shaped or helical protuberances with larger contact surfaces to retain outer diameter and maximize centralization. [0008] In typical stabilizer design, longer and wider protuberances, whether straight or curviform, improve stability but impede the passage of drilling fluid. Longer protuberances likewise typically reduce flexing of the drill string, while shorter protuberances allow more flexing. Protuberance length is determined by the need for directional drilling capabilities of the drill string. Longer and/or wider protuberances also increase rotational drag forces. Longer and wider protuberances, in reducing or impeding drilling fluid flow, can lead to cleaning issues or cause cuttings to foul or aggregate and pack off the fluid passage below the projections. At the same time, the constricted space between protuberances causes increased fluid speed between the protuberances, which may fluffier lead to erosion or abrasion of the protuberances caused by the impact of rock cuttings or other debris against the sides of the protuberances. Exemplary designs of stabilizers are found in U.S. Pat. No. 3,642,079, U.S. Pat. No. 5,330,016, and Chinese patent publication 201,635,674. These examples reflects designs in which stabilizer protuberances are curviform (the '079 patent), straight ('016) or a combination of straight and curviform design elements (the '674 patent). [0009] There is a need for a stabilizer design which effectively moderates these requirements of sturdy design for longevity, a reduced frictional contact surface between the projections and the wall of the borehole, flexibility as to directional containment or directional reorientation, and protuberance design which does not impede or reduce the flow of drilling fluid circulating in the borehole. [0010] The present invention incorporates design elements improving the performance characteristics of the stabilizer as to each of the above needs. SUMMARY OF THE INVENTION [0011] The present invention optimizes stabilizer protuberances in the form of contact pad design to reduce friction, increase fluid flow between such stabilizer contact pads and allow variable flexure without compromising stabilizer strength. The stabilizer contact pads of this invention are based in part on curviform stabilizer pad design while allowing linear flow for drilling fluid axially along the body of the stabilizer. Instead of a single, elongate and curved stabilizer pad, the present invention uses a plurality of smaller contact pads assembled in the approximate shape of a single, curviform stabilizer pads but in which the assemblage of a plurality of contact pads results in a stabilizer pad with reduced surface area and improved flow characteristics. BRIEF DESCRIPTION OF THE DRAWINGS [0012] In the detailed description of various embodiments of the present invention presented below, reference is made to the accompanying drawings, in which: [0013] FIG. 1 depicts a perspective view of an exemplary stabilizer known in the art. [0014] FIG. 2A depicts a cross-sectional view of the exemplary stabilizer known in the art. [0015] FIG. 2B depicts a side view of the exemplary stabilizer known in the art. [0016] FIG. 3 depicts a perspective view of an embodiment of the high annular area, low friction stabilizer design usable within the scope of the present disclosure. [0017] FIG. 4 depicts a perspective view of an alternative embodiment of a high annular area, low friction stabilizer design usable within the scope of the present disclosure. [0018] FIG. 5 depicts a perspective view of an additional alternative embodiment of a high annular area, low friction stabilizer design usable within the scope of the present disclosure. [0019] FIGS. 6A and 6B depict a cross-sectional view and a side view of the embodiment of the high annular area, low friction stabilizer as shown on FIG. 4 . [0020] FIGS. 7A and 7B depict a cross-sectional view and a side view of the embodiment of the high annular area, low friction stabilizer as shown on in FIG. 3 . [0021] FIG. 8A depicts a flow pattern of the known stabilizer depicted in FIG. 1 . [0022] FIG. 8B depicts a flow pattern of the alternative embodiment of the high annular area, low friction stabilizer design depicted in FIG. 4 . [0023] FIG. 8C depicts a flow pattern of the preferred embodiment of the high annular area, low friction stabilizer design depicted in FIG. 3 . DETAILED DESCRIPTION OF THE EMBODIMENTS [0024] Before explaining selected embodiments of the present inventions in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein and that the present invention can be practiced or carried out in various ways. [0025] FIG. 1 depicts a perspective view of a stabilizer known in the art. A hollow or semi-hollow body 14 contains a proximal end 12 a and a distal end 12 b . Each of these ends 12 a and 12 b provide means for connecting the body 14 to another drill string element, not depicted. Connection means are not substantive to the present invention and are not described in detail here. The majority of the body 14 comprises an elongate tubular structure 13 , the diameter of which is fixed, in general, except where protuberances in the form of stabilizer contact pads are placed. The body 14 comprises three substantially identical contact pads 10 , each of which contact pads are curviform in shape and are positioned substantially axially between the proximal end 12 b and the distal end 12 a . The length of each contact pad 10 is less than the length of the body 14 , with the length of a particular contact pad 10 depending upon the specific application of the stabilizer. Longer contact pads 10 are used in drilling operations in which less flexure is required. Shorter contact pad 10 length is used in drilling operations in which more flexure is required, such as in directional drilling operations. Between each contact pad 10 is a junk slot 11 through which drilling fluid containing rock cuttings and other materials flow during drilling operations. [0026] FIGS. 2A and 2B depict cross-sections of the contact pads 10 and junk slots 11 as shown in FIG. 1 . Of significance in these figures is the curviform nature of each of the contact pads 10 as well as junk slots 11 . The curviform nature of each of these results in there being no straight path in any junk slot 11 from the proximal end to the distal end of body 14 . [0027] FIG. 3 depicts a perspective view of a preferred embodiment of the present invention. This preferred embodiment comprises a body 34 , containing a proximal end 32 a and a distal end 32 b , each of which having connecting means to other or additional drill string components not described here. A plurality of interrupted contact pads 30 are placed on the body 34 . Junk slots 31 are co-located with the contact pads 30 , being formed naturally by the placement of any contact pad 30 in close proximity of any other contact pad 30 . In this preferred embodiment, one contact pad 30 may be paired with a closely positioned second contact pad 30 , although this is not necessarily so in other embodiments of the invention. The placement of the contact pads 30 is such that a series of the contact pads 30 are laid out so as to approximate the curviform contact pad of FIG. 1 . To each of the contact pads 30 have been affixed one or more diamond wear elements 33 . [0028] FIG. 4 depicts a perspective view of an alternative embodiment of the present invention. Body 43 provides proximal end 42 a and distal end 42 b thereof in FIG. 4 , a plurality of contact pads 40 and junk slots 41 are laid out in a curviform pattern similar to that as shown in FIG. 3 . In FIG. 4 , however, each contact pad 40 is larger than each contact pad 30 on FIG. 3 , resulting in fewer contact pads on the body 43 . To each of the contact pad 40 have been affixed one or more diamond wear elements 44 . In this embodiment, the contact pads 40 are not associated pairwise as in FIG. 3 . [0029] FIG. 5 depicts a perspective view of an additional alternative embodiment of the present invention. Body 54 provides proximal end 52 a and distal end 52 b . In FIG. 5 , the size, shape and orientation of the contact pads 50 and junk slots 51 are identical to the corresponding features shown on FIG. 4 . FIG. 5 reflects the construction of the invention per FIG. 4 without diamond wear elements 44 . Similarly, the preferred embodiment of FIG. 3 may be constructed without diamond wear elements 33 . [0030] FIG. 6A depicts a cross-section of the embodiment as shown on FIG. 4 . Contact pads 40 and junk slots 41 are shown. FIG. 7A depicts a cross-section of the preferred embodiment as shown on FIG. 3 , similarly depicting contact pads 30 and junk slots 31 . [0031] FIG. 6B depicts a side-view of the embodiment as shown on FIG. 4 showing the layout of the contact pads 40 and junk slots 41 . The substantially curviform layout of the plurality of the contact pads 40 is shown. FIG. 7B depicts a similar side-view of the preferred embodiment as shown on FIG. 3 . [0032] FIG. 8A depicts a side-view as shown on FIG. 21B highlighting the flow path F 1 of drilling fluid through a junk slot 11 FIG. 8B depicts a side-view as shown on FIG. 6B highlighting the flow path F 2 of the drilling fluid through the junk slots 41 . A similar depiction of the flow path F 3 of drilling fluid through the junk slots 31 on FIG. 7B is depicted in FIG. 8C . [0033] The shortcomings of the exemplary stabilizer design depicted in FIG. 1 are evident in that figure. In order to provide stability and/or reduce flexibility, the contact pads 10 must be of a certain length. The curviform shape of the contact pads 10 aid in reducing rotational drag when the upper surfaces of the contact pads are placed against the wall of the borehole during drilling operations. The contact site 15 of the contact pad which is in contact with the wall of the borehole is shown in FIG. 2A . Rotational drag relates directly to the total surface combined surface area of the three contact pads 10 . In the known stabilizer, the total area of the three contact pads in contact with the wall of the borehole is approximately 77 square inches. The total volume of the junk slots 11 in the known stabilizer is approximately 53 cubic inches. [0034] As shown on FIGS. 3 , 7 A, 7 B and 8 C, the design of the preferred embodiment significantly changes that. The present invention uses a plurality of small contact pads 30 manufactured or affixed on the body 34 and set, thereon in approximately curviform form using a series of substantially pair-wise contact pads 30 such that stability or flexure can be achieved depending on the overall length and number of the contact pads. However, the plurality of contact pads 30 allows a, total area in contact with the wall of the borehole to be substantially less than required in the exemplary embodiment of FIGS. 1 , 2 A, 2 B and 8 A. In the preferred embodiment of FIG. 3 , for example, the total area of the contact pads 30 in contact with the wall of the borehole is approximately 46 square inches, while maintaining the same contact length. Similarly, the volume of the junk slots 31 is increased proportionally to the decreased surface area of the contact pads 30 . In the preferred embodiment shown on FIG. 3 , the volume of the junk slots 31 is approximately 77 cubic inches. Specific sizes, shapes, and configurations of assembled features may be modified so as to increase or decrease the total area of the contact pads 30 or the volume of the junk slots 31 as indicated by a particular drilling operation. Likewise, the shape or flow pattern through the junk slots 31 may be modified by the specific placement of the assembled features. [0035] Robustness of the stabilizer depicted in FIG. 3 is maintained by the use of superhard materials for the stabilizer in general and the contact pads 30 in particular. [0036] The layout of the plurality of contact pads 30 on FIG. 3 is approximately uniform and substantially similar to the curviform design of the known stabilizer shown on FIG. 1 . A critical advantage of the present invention is the ability to create and maintain substantially straight flow patterns of drilling fluid between and around the contact pads 30 during drilling operations. As depicted in FIG. 8B and FIG. 8C , embodiments of the invention include contact pads design such that junk slots 41 and 31 , respectively, and flow paths F 3 and F 2 , respectively, run unimpeded from end to end of the body 44 and 34 of each embodiment. Unimpeded flow substantially improves operation in multiple ways. First, unimpeded flow improves the ability of the drilling, fluid to remove rock cuttings by avoiding contact between rock cutting and the sides of contact pads. In curviform contact pads, such as depicted in FIG. 8A , rock cuttings must change direction as the flow path F 1 changes direction, increasing the chance for contact with the side of a contact pad. [0037] Further, in each of the embodiments illustrated on FIGS. 3 , 4 and 5 , increased junk slot volume over the prior art stabilizer of FIG. 1 allows an increase of overall flow of drilling fluid In the known stabilizer of FIG. 1 , the small volume of junk slots 11 reduces flow overall, which may result in rock cuttings and other debris falling out of suspension and not being removed from the borehole. By contrast, the increased volume of junk slots 31 , 41 and 51 in the present invention depicted in FIGS. 3 , 4 and 5 reduces the chance that rock cuttings or other debris may foul or obstruct the fluid passages in the respective junk slot areas. These larger junk slots likewise reduce the tendency of the drilling fluid flow to create areas of turbulent flow, which can increase energy consumption needed to cause the drilling fluid to flow. [0038] The configuration of contact pads and junk slots illustrated on FIGS. 3 , 4 and 5 reflect similar improvements in operation during tripping. It is well known in the field that known stabilizer contact pads drag against the low side of the wall of the borehole when the drill string is removed from the borehole. This drag may result in fouling of the stabilizers caused by balling or packing off the contact pads by the accumulation of particles on such contact pads when pulled through the borehole. In the present invention, as illustrated on FIGS. 3 , 4 and 5 , when the stabilizer is tripped out of the well, the drill string is not in rotation. As such, the contact pads 30 , 40 and 50 , respectively, are aligned vertically, with corresponding channels free of protuberances similarly aligned. This allows cuttings to move unobstructed past the protuberances without any change in trajectory required for spiral pads of traditional configuration. In the event debris starts to accumulate against the side of any of the contact pads 30 , 40 and 50 , respectively, such debris is removed by the drilling fluid as the stabilizer is pulled through the drilling fluid, thereby reducing the chance for balling or packing off. [0039] The configuration as to contact pads 30 , 40 and 50 , and junk slots 31 , 41 , and 51 on FIGS. 3 , 4 and 5 is also advantageous in horizontal and extended reach wells where beds of cuttings exist in the annulus during drilling. The positioning of the contact pads 30 , 40 or 50 is such that they form an interrupted screw shape. Thus when the stabilizer is lying on the low side of a wellbore and rotated, the contact pads effectively push the cuttings towards surface and above each stabilizer. The straight flow channels existing between the contact pads (see FIGS. 8B and 8C ) contribute a hydraulic force that is longitudinally oriented, which assists the screw-type arrangement of the contact pads in forcing bedded cuttings upwards. This helps to reduce or spread out the beds of cuttings in these wells, where rotating torque is a large limitation to drilling depth, by pushing them towards the surface as each stabilizer is rotated. [0040] While various embodiments of the present inventions have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein.
A low friction stabilizer having a body and a plurality of small contact pads configured to function with the effectiveness of a single, larger contact pad is described. The assemblage and configuration of the small contact pads enable the performance of stabilization while reducing rotational drag and while allowing high annular flow around the stabilizer.
4
BACKGROUND OF THE INVENTION This application is a continuation-in-part of commonly assigned application Ser. No. 08/168,606, filed Dec. 16, 1993 abandoned. The present invention is directed to a method of regulating the cloth fell position with respect to the position of the sley in a loom and a loom for the performance of the method. In order to avoid points of start in the fabric, various solutions have been proposed. One solution provides for the displacement of a breast beam arranged to be movable at constant warp thread tension in order to reset the position of the fell of the cloth after a stoppage of the loom. In another solution, in the case of alteration of the yarn density, the kind of weft yarn or the kind of warp yarn, the shift of the fell of the cloth is calculated with the aid of an input of new data and through control of the warp let-off and the cloth take-up to cancel out the shift of the fell of the cloth. A further solution provides, in the case of a stoppage of the loom, to cancel the shift of the fell of the cloth by reduction or reproduction of the warp thread tension. SUMMARY OF THE INVENTION The present invention solves the above described problems by continuously regulating the shifting of the fell of the cloth with respect to the position of reversal of the reed that is caused by the faulty behavior of the elements cooperating with the run of warp to cloth during operation of the loom. In order to determine the shift of the fell of the cloth, the free length of run of warp to cloth and/or the measurement of the delivery of warp and/or cloth and/or the position of at least one element cooperating with the run of warp to cloth is measured in dependence upon the position of the main shaft. The operational behavior of the loom may thereby be incorporated into the method in an advantageous way. It further proves advantageous if the desired values for the measured systems are calculated from a mean value for K weft insertions, whereby a direct relationship may be achieved between the actual and desired values on the running loom. BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained below with the aid of the attached drawings wherein: FIG. 1 is a diagrammatic view of a loom according to the present invention; FIG. 2 is a block diagram of control equipment for the loom of FIG. 1; FIG. 3 is an enlarged view of the detail A of FIG. 1; FIG. 4 is a diagrammatic representation of a feature in accordance with the invention; FIG. 5 is a flow diagram of the course of one form of execution of a method in accordance with the invention; FIG. 6 is a graph of the elasticity constant; FIG. 7 is an example of the modulus of elasticity applied to looms according to the present invention; and FIG. 8 is an example illustrating correction of the cloth fell position after applying the example of FIG. 7. DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the loom contains a main shaft 1 with a signal transmitter 2 for the angular position of rotation of the main shaft, a warp beam 3 which exhibits a driving mechanism 4 with a warp circuit 5 for the warp let-off and a signal transmitter 6 for the warp let-off position, a bearer beam 7, a tension beam 8 with a tension device 9 which is arranged to be movable in order to keep the warp thread tension constant, and a signal transmitter 10 for the position of the tension beam, a reed 11, a breast beam 12, a switch-beam 13 with a driving mechanism 14 and a cloth take-up circuit 15 for drawing off the cloth, a pressure roll 16 and a cloth beam 17 for winding up the cloth. A controller 18 is further provided, which is connected on one side to the signal transmitter 2 for the angle of rotation of the main shaft 1, the signal transmitter 6 for the warp let-off position and the signal transmitter 10 for the position of the tension beam, and on the other side to the driving mechanism 14 of the switch-beam 13. One embodiment of the control equipment is represented in FIG. 2. The control equipment contains a data storage 19, a program storage 20 and a processor 21, which are operatively connected together via data leads on the one hand and to an adaptor circuit 22 on the other. The adaptor circuit 22 is in turn connected to the signal transmitters 2, 6 and 10 and to the cloth circuit 14. FIG. 3 is a diagrammatic representation of the region of the loom in which the actual weaving process takes place. In FIG. 3, the reed 11 is shown in the drawn back position by a dotted line and in the position of reversal by a solid line. The shed formed by the warp threads 24 turns at the fell of the cloth 25 into the cloth 26. The distance L between the fell of the cloth 25 and the reed 11, when lying in the position of reversal, represents the desired value which is regulated according to the method of the present invention. During operation of the loom, (as well as when it is at a standstill) the position of the fell of the cloth alters (due to unsteady behavior of the warp let-off and tension beam) so that between the shifted fell of the cloth 24 and the reed 11, when lying in the position of reversal, there is a distance L' which represents the actual value of the position of the fell of the cloth. The length of the shift in the fell of the cloth follows from the relationship L--L'. Referring to FIGS. 4 and 5, a form of execution of the method will now be described. Upon switching on the loom, the angular position of rotation of the main shaft (i.e., the mesh angle) is measured. The rotation of the main shaft 1 is then monitored. After the main shaft 1 has executed an angle of rotation of n°, e.g., 10°, the length let off by the warp beam, the position of the tension beam 8 and the cloth length wound up onto the cloth beam 17 are measured; for each revolution of the main shaft 1 the same number of measurements are provided. These measured values are actual values and are deposited in the fifo storage 19. These actual values are preferably determined through an optical sensor. From a number of weft insertions, e.g., 20 inclusive of the last weft insertion, average values of the measured values are determined, which are taken as desired values L1, L2 for the free length of cloth and warp. The deviation between the actual and desired values L1, L2 is then determined and the deviation of the fell of the cloth is determined (discussed in more detail below). Through this procedure, the operational behavior of the loom is taken into consideration in an advantageous way for the determination of these desired values L1 and L2. The inventive method for calculating the deviation of the fell of the cloth will now be described. During weaving, the lengths of free warp and cloth alter. On the warp side, the lengths alter through the unsteady behavior of the warp let-off and tension beam 8. On the cloth side, the lengths alter through the unsteady behavior of the cloth take-up circuit. The length is specified by separation points C, D on warp beam 3 and cloth beam 17, respectively, (FIG. 4). The alterations in length ΔL1 and ΔL2 are determined with the aid of a comparison between the actual values and desired values. Since at the fell 25 of the cloth, that is, at the transition from warp to cloth, an equilibrium of force exists, the deviation ΔL of the free fell of the cloth is calculated from the ratio of the moduli of elasticity of the warp and cloth and the lengths L1, L2 of warp and cloth. It is well known that the elasticity modulus is the inverse value of the expansion value. The expansion value is the proportionality factor between expansion (length) and tension (force). Thus, the elasticity constant K equals ΔF×L/ΔL and from that ΔF=K×ΔL/L, as shown in FIG. 6. Referring to FIG. 7, an example of the above theory of elasticity applied to looms will now be described. It should be noted that the following case is merely used to illustrate the invention and the invention is not intended to be limited in that manner. The terms in the following example mean: K1 Elasticity constant of the cloth K2 Elasticity constant of the warp L1 Length of the cloth (from the cloth take up point to the cloth fell position) L2 Warp length (from the cloth fell position to the separation line on the warp beam) is taken as a constant F1 Cloth force F2 Warp force In this example, the length deviations all and ΔL2 from the cloth fell position are very small relative to L1 and L2. As discussed above, a force equilibrium exists at the cloth fell position when an article (cloth and warp) is placed in the loom such that ΔF1=ΔF2. From which is derived: K1/L1×ΔL1=K2/L2×ΔL2 and further ΔL2=K1/K2×L2/L1×ΔL1. During operation of the loom, a deviation in the position of the tension beam caused by friction and/or deviations in the behavior of the warp let-off results in forced length deviation ΔL dev , which is distributed in length deviations in the cloth ΔL1 and the warp ΔL2. From this it can be shown that ΔL.sub.dev =ΔL1+ΔL2 Δa.sub.dev =ΔL1+ΔL1×K1/K2×L2/L1 Because L2 has been taken as a constant, the effective deviation of the cloth fell position is equal to ΔL1, i.e. ΔL cf =ΔL dev ×[1/1(1+K1/K2×L2/L1)](where ΔL cf is the change in the cloth fell position and ΔL dev =L(deviation)). On the basis of this model, the correction value for the length of run of warp to cloth is calculated repeatedly in the processor L1. It should be noted that other factors may be taken into account in determining the correction value, such as the number of warp threads removed during operation of the loom, a change of weave during operation of the loom and the like. In the case of the present embodiment the correction value is calculated for the cloth side. The position of the breast beam 12 and/or of the cloth take-up circuit 15 is then adjusted accordingly to move the cloth fell 25 to the desired value L1. To correct the cloth fell position, ΔL cf can be balanced by adjusting the cloth length, ΔL corr , as shown in FIG. 8. In the corrected state, the entire change in the length of the warp is equal to the force length deviation ΔL dev . The required correction is based on the force equilibrium. ΔL corr is replaced with all and ΔL dev is replaced with L2. From this: ΔL.sub.corr =ΔL.sub.dev The correction factor (k2/k1×L1/L2) has a constant value for a particular weave and for the adjustment of the weaving machine; in which k2/k1 is a function of the type of weave and the geometric configuration of the weaving machine. The correction factor on a weaving machine may be ascertained simply by making an adjustment in the warp let-off direction to ΔL dev when the shed is closed, then measuring the distance ΔL corr from the cloth take-up line about which the fell of the cloth is to be displaced, in order to attain the original position. It is also possible to calculate the correction value for the warp side. In this case, the correction value for the warp let-off and/or the position of tension beam 8 is calculated and then the tension beam 8 and/or the warp let-off is adjusted accordingly to move the cloth fell into the desired value L2. Besides the possibilities name above, other elements in operative connection with the run from warp to cloth may also be set accordingly. The described method is particularly useful if the loom is being taken into service again after a stoppage. Through the determination of the desired value with the loom running, the setting may be performed essentially on the basis of the arithmetical model. If the stoppage has been triggered through breakage of a weft yarn, the desired value may be corrected with respect to the weft yarn removed without additional outlay in apparatus technology. In determining the average value, the change of weave may also be taken into consideration.
A system and method for regulating the cloth fell position in a loom. The desired lengths of cloth and warp thread are determined by averaging the actual values over a given number of weft insertions. The actual lengths of the cloth and warp thread are then continuously measured and compared with the desired values during weaving to compute warp and cloth offset values. A correction factor is determined based on the offset values and the moduli of elasticity of the warp thread and cloth. The cloth fell position is then corrected by adjusting either the actual length of the cloth or the warp thread based on the correction factor.
3
BACKGROUND OF THE INVENTION 1. Field of the Invention The invention generally relates to a process for spinning cotton yarns. More specifically, the invention relates to a process for producing dyed spun cotton yarns having minimal irregularities and increased luster and tenacity, and the yarns thus produced. 2. Description of the Prior Art For thousands of years, cotton yarns have been used in the production of apparel and other goods. In addition to being cost efficient, cotton has good absorbency, is comfortable to wear, launders well, and tends to be relatively durable. Cotton fibers are the hairs which grow on the cotton seeds. Cotton is harvested when mature, and taken to a cotton gin where the fibers, also known as cotton lint, are stripped from the seeds. If performed well, the ginning process minimizes the pick-up of unwanted plant material, while retaining some of the natural oils on the fibers. The fibers are then combined and compressed into large bales (generally on the order of about 500 pounds each) and transported for processing. Because cotton is a natural fiber, it can come in many varying forms. In addition to their being various types of cotton plants themselves, the cotton lint produced can be affected by the composition of the soil, amount of rainfall and sunlight which the plant receives, etc. As a result, individual fibers can vary in shape, diameter, and in fiber length, etc., with the longer length fibers being generally preferred for high quality apparel applications. Because cotton fibers are hair-like, they also have a tendency to become entangled with each other during processing. Such thickness variations, tangles and trash result in irregularities in the yarns which the fibers are used to produce; it therefore can be desirable to reduce the number of such variations and tangles during the processing steps prior to yarn spinning. As noted above, the cotton fibers are generally provided to a yarn spinning facility in bale form. These bales are then broken up and trash is removed from the fibers. This process is commonly referred to as "opening", and the fibers emerge from the opening process in a loose, fluffy mass. However, this mass may still include significant amounts of trash and short and tangled fibers, which need to be removed before the fibers can be spun into a high quality yarn. Cotton fibers are therefore typically processed through an operation known as carding, to remove the undesirable trash, neps (small knots of entangled fibers that will not usually straighten to a parallel position during carding), and noils (fibers which are undesirably short). In the carding machine, the clumps of fiber are contacted with pin-covered rollers which grab and remove a number of the tangled and short fibers and trash and align the fibers. The emerging carded stock is generally condensed to form card sliver. Where a high degree of yarn uniformity is desired, the card stock can be further processed through a combing machine. In one common form of combing operation, a number of ends of card sliver are fed in the form of a lap to the combing machine. In the combing operation, fine metal wires are used to clean out a number of remaining short fibers and other impurities. The combed stock is then generally condensed into what is known as comber sliver. Because the comber is designed to remove small impurities, it thus generally results in a loss of a relatively large percentage of the input fiber material; for example, as much as 17 percent of the input material can be lost as a result of a typical combing operation. In order to minimize this loss of material and to prevent damage to the combing machine, heretofore it has been considered to be critical that the fibers which are input to the combing machine are in an aligned and trash-free condition. Where the production of colored yarns is desired, the cotton fibers are conventionally carded and then dyed. For the production of colored yarns having fewer irregularities, manufacturers typically comb the natural fibers as well. Because dyeing tends to entangle the fibers with each other and the fibers emerge from the dyeing process in a matted form, it has heretofore been the industry standard to comb the fibers prior to the dyeing process, as it has been considered to be necessary that the fiber stock fed to the dyeing machine was well aligned to prevent the significant further entanglement of the fibers during the dyeing process. However, the dyeing process tends to impart tangles and mat the fibers together, such that subsequent separation of the fibers for spinning results in the imparting of additional neps and tangles. To avoid this problem, yarn manufacturers often spin combed natural (i.e., undyed) cotton fibers with dyed card stock, then label the resulting product as a combed dyed yarn. Despite traditional carding and combing operations, the yarns produced by prior art methods still contain a number of irregularities, such as thick and thin areas and neps or slubs. Depending on the fabric being produced by the yarns, the appearance of the neps may or may not present a significant problem. For example, in some types of fabrics, the neps are seen to add to the character of the fabric while in others, a nep appearing within a garment can result in its failing quality inspection and being classified as a factory second or low quality fabric. The appearance of neps tends to become a more significant issue in yarns containing a blend of more than one color of fibers. For example, in grey yarns made from a mixture of black and white fibers, the appearance of a black nep can significantly diminish the visual appearance of a fabric made from the yarns. Another difficulty encountered in the production of spun cotton yarns which mix more than one color of fiber is that it is difficult to get a consistent blend of the colors. As a result, knit fabrics produced from conventional multi-colored yarns often have what is known as a banding or window pane effect, in which bands of one of the fiber colors stand out in the knit fabric. With the foregoing in mind, it is therefore an object of the present invention to provide a process for providing dyed spun cotton yarns having improved uniformity and color consistency. It is also an object of the present invention to provide a method for making spun yarns having improved luster, and which can be produced at competitive rates of production with prior art methods. SUMMARY OF THE INVENTION These and other objects are provided by the process of the instant invention, in which at least a portion of the fibers forming a yarn are combed subsequent to the fiber dyeing process. As noted above, conventional wisdom dictates that fiber dyeing is performed subsequent to any fiber alignment steps such as carding and combing. This is because dyeing processes are generally wet processes, which have a tendency to drastically increase fiber entanglement, with the increase in entanglement correlating with the initial degree of entanglement. For purposes of illustration, the entanglement is similar to the case of hair washing, where hair which is initially entangled has a tendency to become dramatically more entangled when washed, as opposed to hair which is brushed prior to washing. Thus, one would expect that it would be physically impractical to comb dyed fibers subsequent to the dyeing operation, without inflicting tremendous damage to the long fibers and removing a large percentage of the input fiber. In addition, because of the matted, hard condition in which the fibers emerge from the dyeing process, one would expect that conventional combing equipment could not be used to comb dyed fibers, without damage to and build up of fibers on the comber. Surprisingly, however, the instant inventor has discovered that by combing the fibers subsequent to the dyeing operation, spun yarns having greatly improved uniformity can be readily and efficiently produced. Furthermore, it has been found that by blending multiple colors of fibers prior to the combing operation, yarns having a much greater intimacy of color blend can be achieved, while not affecting the overall color of the yarn. In addition, the thus-produced yarns have greatly enhanced luster and softness, as well as tenacity. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a flowchart illustrating steps taken during the process of the instant invention; and FIGS. 2A and 2B, when joined at their respective boken ends, show a table of Uster Evenness Test results corresponding to Example 1; FIGS. 3A and 3B, when joined at their respective broken ends, show a table of Statimat M Single End Test results corresponding to Example 1; FIGS. 4A and 4B, when joined at their respective broken ends, show a table of Uster Evenness Test results corresponding to Example 2; FIGS. 5A and 5B, when joined at their respective broken ends, show a table of Statimat M Single End Test results corresponding to Example 2; FIGS. 6A and 6B, when joined at their respective broken ends, show a table of Uster Evenness Test results corresponding to Example 3; FIGS. 7A and 7B, when joined at their respective broken ends, show a table of Statimat M Single End Test results corresponding to Example 3. DETAILED DESCRIPTION OF THE INVENTION The present invention now will be described more fully hereinafter with reference to the accompanying drawing, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. With reference to FIG. 1, bales of cotton fibers are opened in a conventional manner. The fibers can optionally go through an initial carding process to provide some alignment at this stage of the process. In the process according to the instant invention, cotton fibers are dyed to achieve a predetermined color, using conventional fiber dyeing methods such as batch dyeing. (For purposes of this application, the term "cotton fibers" is meant to describe batches of fibers in which a major portion of the fibers are the seed hairs from the seeds of cotton plants. The batches may also include other types of fibers conventionally used in combination with cotton fibers, within the scope of the instant invention.) The dyed yarns are then carded according to conventional carding methods, and may go through an initial drawing stage as well, although not required. The fibers are then combed using commercially available combing machinery, such as the Saco-Lowell Calif. comber. In a preferred form of the invention, a combing machine set up with approximately 1420 teeth per square inch (as opposed to the industry standard of about 1002 teeth per square inch) has been found to perform well in combing the dyed fibers. Such a high tooth gauge is particularly surprising, since one would expect that the tangled state of the fibers which are input to the comber would necessitate the use of a less aggressive combing arrangement. In addition, in a preferred form of the process of the invention, the air suction on the comber is increased from conventional levels to optimize the condition of the fiber output, and top combs which are in pristine condition are desirably used. While one would expect such conditions to be too aggressive even for natural fibers, the inventor has surprisingly discovered that the combed fibers are in excellent condition and that the tangled fiber input does not damage the comber, as one might expect. In a preferred form of the invention, the combing of the dyed fibers is performed to remove about 21-22% noils (as compared with about 17% noil removal from a "world class" combing of natural fibers). In one form of the invention, fibers of two or more colors (one of which may be the color of the natural cotton fibers in their undyed form and at least one of which is dyed) are blended together, then all of the fibers are combed. In this form of the invention, it has surprisingly been found that the color of yarn which would be expected from conventional yarn processing methods of like-colored fibers is achieved, while the individually-colored fibers are more intimately blended together than with the conventional processing methods, so as to result in a more consistent color throughout the yarn. In another form of the invention used to produce mixed-color yarns (e.g., heather yarns), the manufacturer determines which of the colors to be blended in the yarn will be the dominant fiber color. For example, grey heather yarns generally include about 9% black fibers and the rest natural-colored fibers. In such yarns, black is the dominant fiber color and in fabrics produced from the grey heather yarns, the black neps therefore have a tendency to show up more prominently than the naturally-colored neps. Therefore, in this embodiment of the invention, the manufacturer combs the dyed fibers which it has been determined will present the most dominant visual appearance (i.e., in the example, the black fibers), such that fewer irregularities exist in that fiber color. As a result, blended yarns spun from the dominantly-colored dyed combed fibers and the other colored fibers have a slightly lower overall nep count as compared with prior art yarns formed from like-colored fibers. (As will be understood, the reduction in overall nep count will depend somewhat on the percentage of the fibers forming the yarn which have been combed subsequent to dyeing. However, by strategically selecting which of the fiber inputs are to be combed, and by the inventor's development of a process for combing fibers subsequent to the dyeing process, marked improvements in yarn quality can be achieved through the use of only a small percentage of the dyed-then-combed fibers relative to the overall yarn composition.) Therefore, when the thus-produced yarns are formed into a piece of fabric, the overall appearance is that of a dramatic reduction in yarn neps. Thus, with only a minimal processing adjustment, a surprisingly remarkable increase in fabric quality can be realized. In addition, the thus-produced yarns have a dramatically reduced coefficient of variation, a reduced number of thick and thin places, increased breaking factor, and increased tenacity. Furthermore, the thus-produced yarns have a readily visible increase in luster, which greatly enhances the appearance of the yarn. In fact, in many of the yarns, and particularly those in which a dyed fiber quantity is combed prior to blending with a second quantity of fibers, and the blended fibers are then combed together, the resulting yarns are substantially free of visual irregularities, and fabrics produced from the yarns are substantially free of neps and visual irregularities. Thus, the instant invention enables the achievement of dramatic functional as well as aesthetic improvements. In an alternative form of the invention, fibers are dyed then combed, then blended with fibers of another color. The blended fibers are then combed together, and spun into a yarn. The thus-produced yarns have enhanced luster over that of their conventionally-spun counterparts, and while the color is substantially the same as that which is achieved by conventional comb-then-dye methods of spinning blended yarns (as described above), the colors are significantly more intimately blended. The result is a yarn having a much lusher appearance than that of conventional yarns. In addition, the yarns have been found to be much softer, particularly when spun using ring spinning methods. It is to be noted, however, that fibers processed according to the instant invention can be formed into yarns using any conventional method, including but not limited to ring spinning, open end spinning, and air jet spinning methods. In fact, the fiber preparation process enables the production of finer-size open end spun yarns than have heretofore been achievable at commercially acceptable levels of production, since the improved consistency of the dyed fiber input results in fewer ends down during the spinning process. In a particularly preferred method of the invention designed to achieve virtually nep-less heather yarns, the dyed fibers are combed, blended with natural fibers, and the blended fibers are combed together. As a result, the dyed fibers have thus undergone two combing operations. In this way, extremely high quality, soft yarns are produced which have more intimate fiber blending. Because the dyeing process often has a tendency to strip some of the natural oils from the fibers, it has also been found to be desirable in some cases to add one or more conventional types of lubricant to the fibers prior to combing them, particularly where the ginning process has removed more than an optimal level of the fibers' natural oils. The amount and types of such lubricants can be readily selected depending on the particular batch of cotton fibers being processed without undue experimentation by someone having ordinary skill in the art. EXAMPLES A variety of yarns were prepared according to various embodiments of the instant invention, and the results are outlined below for purposes of comparison with the physical characteristics of conventionally-produced yarns. For purposes of description below, the term "scratch combed" is used to describe the combing of fibers which was performed at a machine set-up designed to remove approximately 2-4% of the fiber noils. As noted above, scratch combing is a common level of aggressiveness at which fibers are combed. Also for purposes of the examples, the term "Process 2 Combing" is intended to describe combing using a more aggressive machine set-up, to remove about 17% or greater of fiber noils. In all of the examples, the highest quality 11/8" staple length cotton fibers were used. Each of the samples was then measured to determine the average yarn size, and four 400 yard lengths of each yarn sample were analyzed using a Uster Evenness Tester to determine the coefficient of variation of each, number of thick and thin places, and the number of neps (i.e., piece of fiber which breaks and balls up, forming a pill on the outer surface of the yarn.) It is noted that the terms "thick" and "thin" places are recognized terms of art detected by the Uster Evenness Tester, as will be readily appreciated by those having ordinary skill in the art. The averages of each of these criteria were then calculated. Elongation, force to break and yarn tenacity were then measured on twenty-five single ends of each yarn using a Statimat M Single End Tester in its conventional manner, as will be readily understood by those having ordinary skill in the art. The gauge length was set at 254 mm, the load cell at 10 N, the preload was 0.50 cN/tex, and the test speed was 5000 mm/min. Again, the average of each of these measurables was calculated, as was the break factor for each of the yarns. Example 1 Samples A, B and C of forest green yarns including 80% dyed fibers and 20% natural fibers were produced as follows. A twist test was conducted for each of the yarns to determine the average turns per inch (tpi) and average twist multiple (tm), as noted below: A. 18/1 Ne 100% cotton yarns were produced from 80% dyed fibers and 20% natural fibers which were carded together, but not combed. The yarn had an average twist of 15.9 tpi and an average twist multiple of 3.8. B. 18/1 Ne 100% cotton yarns were produced from a blend of 20% natural fibers which were combed according to Process 2 and 80% dyed (uncombed) fibers. The yarn had an average twist of 16.2 tpi and an average twist multiple of 3.9 C. 18/1 Ne 100% cotton yarns were produced from a blend of 80% dyed fibers and 20% natural fibers which had been combed according to Process 2, with the blended fibers being combed together according to Process 2. The yarn had an average twist of 16.2 tpi and an average twist multiple of 3.9. The results of the measurements of Samples A, B, and C are listed in the tables labeled as FIGS. 2A, 2B, 3A, and 3B. As illustrated, the yarns prepared according to the instant invention (i.e., Sample C) had dramatically reduced numbers of thick and thin places, as well as a dramatic reduction in the number of neps. Furthermore, the fiber evenness is dramatically improved, as illustrated by the significant reduction in the coefficient of variation of the yarns of Sample C as compared with those of Samples A and B. In addition, the spread between the highest coefficient of variation and the lowest coefficient of variation for the product made according to the instant invention (Sample C) is also substantially smaller than the spread between the highest and lowest coefficients of variation of the yarns made according to conventional processes (i.e., Samples A and B.) This indicates that yarns made according to the instant invention are consistently more uniform than those which are made according to prior art methods. Furthermore, the tenacity, the elongation, and the force to break were substantially improved. Example 2 Samples D, E and F of dark grey yarns including 50% dyed fibers and 50% natural fibers were produced as follows. A twist test was conducted for each of the yarns to determine the average turns per inch (tpi) and average twist multiple (tm) as noted below: D. 18/1 Ne 100% cotton yarns were produced from a blend of 50% scratch combed natural fibers and 50% fibers which were scratch combed, then dyed black. The thus-prepared fibers were then carded together and spun into a yarn. The yarn had an average twist of 16.0 tpi and an average twist multiple of 3.8. E. 18/1 Ne 100% cotton yarns were produced from 50% natural fibers which were combed according to Process 2 and 50% fibers which were scratch combed, then dyed black. The thus-processed fibers were then spun into a yarn having an average twist of 16.5 tpi and an average twist multiple of 3.9. F. 18/1 Ne 100% cotton yarns were produced from 50% natural fibers which were combed according to Process 2 and 50% fibers which were dyed black, then combed according to Process 2. The fibers were blended and combed together according to Process 2. The yarn had an average twist of 16.9 tpi and an average twist multiple of 4.0. The results of the measurements of Samples D, E and F are listed in the tables in FIGS. 4A, 4B, 5A, and 5B. As illustrated, the average coefficient of variation for the yarns made according to the instant invention (Sample F) was substantially lower than that for the conventionally produced yarns (Samples D and E), as was the average number of thick and thin places. For example, the Sample F yarns had an average of 22 thick places per 400 yards, as compared with 1291 in the Sample D yarns. Furthermore, the Sample F yarns averaged only a single thin place per 400 yard length, as compared with 355 for the Sample D yarns, and the average number of neps for the Sample F yarns was a mere 7 per 400 yard length of yarn. Furthermore, increases in the average break factor, force to break and tenacity were realized. Example 3 Samples G, H, I, and J of light grey yarns including 9% black dyed fibers and 91% natural fibers were produced as follows: G. 18/1 Ne 100% cotton yarns were produced from 9% fibers scratch combed as natural, then dyed black and 91% carded natural fibers, with the blended fibers being carded together prior to spinning. The yarn had an average twist of 16.6 tpi and an average twist multiple of 3.9. H. 18/1 Ne 100% cotton yarns were produced from a blend of 9% fibers which were dyed black, then combed according to Process 2 and 91% natural uncombed fiber stock. The yarn had an average twist of 16.1 tpi and an average twist multiple of 3.7. I. 18/1 Ne 100% cotton yarns were produced from 9% fibers which were dyed black, then combed according to Process 2. The dyed combed fibers were blended with 91% natural fibers which had also been combed according to Process 2, and then the blend was combed together according to Process 2. The yarn had an average twist of 16.7 tpi and an average twist multiple of 3.9. J. 18/1 Ne 100% cotton yarns were produced from 9% fibers which were dyed black, then combed according to Process 2 and 91% carded natural fibers, and the blended fibers were then combed together according to Process 2. The yarn had an average twist of 15.8 tpi and an average twist multiple of 3.8. The results of the measurements of Samples G, H, I and J are listed in the tables in FIGS. 6A, 6B, 7A, and 7B. As indicated in the tables, the yarns made according to the instant invention (i.e., Samples H, I, and J) had lower coefficients of variation (particularly those of Samples I and J, where the blend including the dyed fiber component was combed together.) As indicated, the average number of thick and thin places in Samples I and J was reduced to zero. Furthermore, as indicated by a comparison of Samples G and H, the combing of the dyed fibers after the dyeing process rather than before it produced dramatic reductions in the number of thin and thick places as well as the number of neps. Thus, yarns made according to the instant invention were found to be more consistently uniform and had reduced thick and thin regions, as well as reduced number of neps. Because the neps are generally readily visible when the yarn is knit or otherwise formed into a fabric, the reduction in neps achieved by the instant invention results in the ability to produce higher quality fabrics with dramatically fewer neps. In addition, the yarns produced according to the instant invention had improved luster, with the blending of the fiber colors being more intimate throughout the yarn. Furthermore, the yarns were stronger than those produced by prior art methods (as illustrated by the increase in force required for break), and the yarns were more consistent in strength, as illustrated by the smaller spread between the highest and lowest forces required for break of the yarn. Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawing. 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 process for producing dyed spun cotton yarns having a reduced number of irregularities and increased luster is described. The process involves dyeing at least a portion of the cotton fibers which are to form the yarn, then combing the dyed fibers subsequent to the dyeing process. The dyed and combed fibers are then optionally blended with fibers having a visually distinct appearance, and spun into a yarn using conventional spinning methods. The resulting yarns having a dramatically reduced number of thick and thin places and improved yarn properties including improved luster and hand. Furthermore, when the thus-dyed fibers are blended with differently-colored fibers prior to the combing operation, the resultant yarns match the visual colors of like-colored yarns produced by conventional processes, while the color is more intimately blended and the yarns have a markedly increased uniformity, luster and tenacity. As a result, fabrics produced from the yarns have a superior appearance with respect to color blend and luster, and the number of neps and irregularities are dramatically reduced with respect to those of conventionally-produced fabrics.
3
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application No. 60/386,338 filed on Jun. 6, 2002, the contents of which are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates generally to friction-force actuators, and particularly to friction-force actuators that can be adapted for use in operating secondary mechanisms of a wheelchair lift where safety is a concern. BACKGROUND OF THE INVENTION Wheelchair lifts are provided for facilitating the loading of wheelchairs and wheelchair occupants on and off vehicles. When the lift is used to load a wheelchair onto the vehicle, the lift is positioned at the ground level and is configured to allow the wheelchair and its occupant to roll onto a platform. Once the wheelchair has been loaded onto the platform, a barrier or roll stop is raised at the end of the platform assembly to prevent the wheelchair from rolling off of the platform while the lift is in motion. Barriers may be provided on the front end of the platform, the back end of the platform, as well as both sides of the platform to ensure the safety of the wheelchair occupant. When the wheelchair lift is raised to the vehicle entry level, the vehicle-side barriers drop, allowing the wheelchair to exit the platform onto the vehicle. Similarly, when the wheelchair is unloaded from the vehicle, the lift is positioned at the entry level of the vehicle, with the vehicle-side barriers down, to allow the wheelchair access to the platform. When the wheelchair is securely positioned on the platform, the barriers are raised to prevent the wheelchair from rolling off of the platform during transport. The platform is then lowered from the entry level position to the ground level position. Upon arrival at the ground level, the barriers opposite the vehicle are released and lowered to allow the wheelchair to exit from the platform onto the ground. It is desirable to provide a device for automating the raising and release of the platform barriers to avoid the need to manually engage the barriers during each use. Accordingly, it is desirable to provide an actuator that automates the operation of the barriers. Although automatic operation of the barriers is desirable, from time to time, there may be a need to manually operate the barriers. Typically, the manual operation of automated devices requires the disengagement of the actuator and the movement of the barrier by hand. The disadvantage of these known devices is that manual operation of the barriers often causes the device to become mechanically “lost,” i.e., after manual operation, the device is left out of sequence. As a result of being out of sequence, when the device is reactivated, it often gets jammed or otherwise malfunctions. Accordingly, there is a need for an actuator that automates the operation of the barriers while still allowing manual operation thereof as needed, without requiring disengagement of the actuator from the barrier during manual operation, and without resulting in the mechanical mis-sequencing of the device. The automation of the barriers raises certain safety issues. Although desirable to automatically move the barriers up and down during each use, there may be some situations in which the motion of the barriers should be limited. For example if someone's foot is positioned underneath the barrier, for safety purposes, the actuator should be limited in the amount of force it applies to the barrier. Accordingly, it is desirable to provide an actuator that limits the amount of force it applies to the barrier upon contact with an intervening obstacle. SUMMARY OF THE INVENTION A clutch-driven limited force actuator is disclosed having a motor, a planetary gear mechanism in operative communication with the motor and a clutch plate. The clutch plate includes a contact surface in frictional contact with the planetary gear mechanism and applying a selective amount of force to drive an actuator arm. In operation, the frictional force between the planetary gear mechanism and the clutch plate causes the actuator arm to actuate. The actuator arm can be connected to any element that requires actuation. The actuator of the present invention is preferably used in a wheelchair lift to actuate the barriers of the lift. In a preferred embodiment of the invention, the planetary gear mechanism includes a plurality of planetary gears orbiting the spindle of the motor and a ring gear engaged with and driven by the planetary gears. The clutch plate is biased toward the ring gear by a wave washer and is selectively in frictional contact with the ring gear. In operation, the clutch plate rotates with the ring gear when the plate is in frictional contact with the ring gear. When the frictional force is overcome, the clutch plate will no longer rotate, even if the motor continues to operate. Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be more readily understood by referring to the accompanying drawings in which: FIG. 1 is a perspective view of a preferred embodiment of the clutch-driven limited force actuator of the present invention; FIG. 2 is an exploded view of a preferred embodiment of the clutch-driven limited force actuator of the present invention; FIG. 3 is a top plan view of a preferred embodiment of the clutch-driven limited force actuator of the present invention; FIG. 4 is a cross-sectional view of the clutch-driven limited force actuator of FIG. 3 , taken along line 4 — 4 ; and FIG. 5 depicts a preferred embodiment of the clutch-driven limited force actuator of the present invention as installed on a wheelchair lift. Like numerals refer to like parts throughout the several views of the drawings. DESCRIPTION OF THE INVENTION FIGS. 1 through 4 illustrate a preferred embodiment of the clutch-driven limited force actuator 10 of the present invention. The actuator 10 includes a motor 12 , a planetary gear mechanism 20 , a pressure plate or clutch plate 30 and an actuation stop plate 40 . The motor 12 is preferably a 12 volt direct current motor having a clockwise rotation. It is envisioned that various types of motors can be used in the actuator of the present invention without departing from the spirit or scope of the present invention. The planetary gear mechanism 20 preferably includes a sun gear 22 , ring gear 24 and a plurality of planetary gears 26 . As best shown in FIGS. 1 and 4 , in a preferred embodiment of the present invention, the sun gear 22 is attached to the spindle of the motor 12 . When the motor 12 operates, the sun gear 22 spins. The planetary gears 26 surround the sun gear 22 and have teeth 27 to facilitate the rotation of the planetary gears 26 with respect to the sun gear 22 . The sun gear 22 includes teeth corresponding to the teeth 27 on the planetary gears 26 to facilitate the rotation of the planetary gears 26 about the sun gear 22 . To preserve the positioning of the planetary gears with respect to each other, in a preferred embodiment of the invention, the planetary gear mechanism 20 includes a planetary gear carrier plate 28 . The planetary gear carrier plate 28 preferably includes a plurality of carrier posts 29 , each post corresponding to a planetary gear 28 . Each planetary gear 28 is mounted on a carrier post 29 and rotates thereon. The carrier post 29 provides the pivot axis for the rotation of the planetary gear 28 . When the sun gear 22 rotates, it causes the rotation of the planetary gears 26 with respect to the sun gear 22 . Because the teeth 27 of the planetary gears 26 are engaged with the teeth 25 of the ring gear 24 , the rotation of the planetary gears 26 drives the ring gear 24 . The number of planetary gears 26 , and the number of teeth on each of the planetary gears 26 , ring gear 24 and sun gear 22 can be varied without departing from the inventive concept of the present invention. In a preferred embodiment of the invention, the planetary gear mechanism 20 includes three planetary gears 26 , each having six teeth 27 thereon, a ring gear 24 with twenty-one teeth 25 , and a sun gear 22 . The planetary gear mechanism 20 , and more preferably the ring gear 24 , is in frictional contact with the clutch plate 30 . The frictional force between the planetary gear mechanism 20 and the clutch plate 30 is controlled by a biasing device 50 . In a preferred embodiment of the invention, the biasing device 50 is a wave washer. The wave washer 50 is positioned such that it exerts force on the clutch plate 30 , causing the clutch plate 30 into frictional contact with the planetary gear mechanism 20 . The underside 32 of the clutch plate 30 preferably contacts the ring gear 24 . When the ring gear 24 rotates, the frictional force on the clutch plate 30 causes the clutch plate to rotate together with the ring gear 24 . As a result, the actuator arm 34 also rotates. In a preferred embodiment of the invention, the clutch plate 30 and ring gear 24 are made of different materials to prevent galling. The clutch plate 30 is preferably made of a bearing material such as brass or bronze. The ring gear 24 is preferably made of steel. Given the force applied by the wave washer 50 and the contact surface area between the clutch plate 30 and ring gear 24 , both of which are designed properties of the assembly, those skilled in the art will be able to calculate the friction force between the clutch plate 30 and the ring gear 24 . The friction force directly equates to the amount of force the actuator arm 34 can exert. As long as the clutch plate 30 is in frictional contact with the ring gear 24 , the actuator 10 applies a constant force on the actuator arm 34 . If additional force is required, the strength and the compression of the biasing device or wave washer 50 can be increased, causing it to apply additional biasing force on the clutch plate 30 . To limit the rotation of the clutch plate 30 , the actuator 10 of the present invention preferably includes an actuation stop plate 40 . In a preferred embodiment of the invention, the actuation stop plate 40 includes a plurality of apertures 42 that correspond to apertures 14 on the motor 12 . Spacers 16 are placed between the stop plate 40 and the motor 12 to attach the actuation stop plate 40 spaced apart from the motor 12 . Upon alignment of the spacers 16 and the apertures 14 , 42 , the actuation stop plate 40 is fastened to the motor 12 . When attached to the motor 12 , the actuation stop plate 40 provides a first limiting member 44 and a second limiting member 46 . The rotation of the actuator arm 34 is limited by the first and second limiting members 44 , 46 . The distance between the first and second limiting members 44 , 46 represents the range of motion of the device actuated by the actuator arm 34 . The actuator 10 of the present invention is never thrown out of sequence. There are no surfaces that separate and re-engage each other. Upon operating the motor 12 , the actuator arm 34 will travel until it reaches a limiting member 44 , 46 . If the motor 12 continues to run after the actuator arm 34 has reached a limiting member, the force of the limiting member on the actuator arm 34 overcomes the friction force between the clutch plate 30 and the planetary gear mechanism 20 and the clutch plate 30 will no longer rotate with the ring gear 24 . Accordingly, the actuator will not jam or otherwise become mechanically “lost.” spacers 52 , spacer plates 54 , wear plates 56 and washers 58 can be used as known by those in the art to ensure smooth operation of the various components of the actuator. It is envisioned that the clutch-driven limited force actuator 10 can be used in a variety of applications. In a preferred embodiment of the invention, as best shown in FIG. 5 , the actuator 10 is used in a wheelchair lift 100 to facilitate the movement of the barriers 110 . Actuator arm 34 is operatively connected to a barrier 110 by an extension arm 112 . When actuated, the actuator arm 34 actuates the barrier 110 via the extension arm 112 . The frictional force between the clutch plate 30 and the planetary gear mechanism 20 is adjusted to be sufficient to overcome the force of the barriers 110 and to move the barriers to the position desired. If during deployment of the barriers 110 , an obstacle is encountered, or in the event that the barriers must be manually operated, the actuator will limit the application of force with minimal interruption and effect on the operation of the actuator. For example, if an obstacle is placed in the path of the barriers, the force of the obstacle will cause the clutch to slip. While the motor is operating, the ring gear 24 will continue to turn, sliding on the clutch plate 30 and thereby applying force to the actuator arm 34 . However, the force applied by the actuator arm 34 is limited. Upon removal of the obstacle, the actuator arm 34 continues rotating and applying force on the barriers. The actuator is never taken out of sequence and it is not necessary to disengage the actuator from the barrier to manually operate the barrier. The embodiments described above are exemplary embodiments of a clutch-driven limited force actuator of the present invention. Those skilled in the art may now make numerous uses of, and departures from, the above-described embodiments without departing from the inventive concepts disclosed herein. Accordingly, the present invention is to be defined solely by the scope of the following claims.
A clutch-driven limited force actuator is disclosed having a motor, a planetary gear mechanism in operative communication with the motor and a clutch plate. The clutch plate includes a contact surface selectively in frictional contact with the planetary gear mechanism to drive an actuator arm. In operation, the frictional force between the planetary gear mechanism and the clutch plate causes the actuator arm to actuate. The actuator arm can be connected to any element that requires actuation. The actuator of the present invention is preferably used in a wheelchair lift to actuate any mechanism that must have a safe limit on the amount of force applied to obstacles and that must have provision for direct manual operation.
0
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a fabric. More particularly, the invention relates to a fabric comprising a fiber substrate, a parylene layer, and an antibacterial layer. [0003] 2. Description of the Related Art [0004] In the past, displays or monitors had little extra value besides providing an audiovisual effect. Due to their monotonous cubic shapes and limited color combinations, the styles of these displays seldom provide customers with an aesthetic effect or an eye-catching design. However, as a result of the burgeoning aesthetics and the popularized personalism in recent years, more and more people prefer products with better design and uniqueness; therefore, several display manufacturers begin to pay attention to the appearances of displays and, on the market, more and more displays are featured by an avant-garde color combination as well as an extraordinary shape. Among all means to increase the aesthetic effect or designs of the displays, covering a display with a fabric is the one that may increase viewers' enjoyment during the provision of an audiovisual effect. [0005] However, because of the their inherent property, fabrics are more prone to absorb moisture from the air than plastic casings; in addition, after being handled or placed at a spot for a long period of time, the fabric may easily be covered by dust and bacteria, becoming a hotbed for pathogenic germs. [0006] In order to provide an antibacterial and dustproof effect, several inventions, which treat a fabric or the like with nano-sliver, nano-photocatalysts or the composition thereof as an additive or a coating agent, have been disclosed. Taiwan Patent No. M249056 discloses a computer comprising a photocatalyst layer; furthermore, TW200536987 relates to a method for producing a fabric with nano-silver and a nano-silver containing fabric. Similarly, M249967 discloses a nano-silver containing fabric as well, and U.S. Pat. No. 6,979,491 is directed to yarn containing nano-silver particles. After reviewing all the patents aforementioned, one can easily find that the antibacterial effect of an article comes from the addition the nano-silver particles and/or nano-photocatalyst. However, since fiber substrates belong to organic compounds, they may also be decomposed consequently as a result of the catalysis reaction of the photocatalyst, given that no proper protection or isolation is provided. Thus, the above-mentioned inventions fail to satisfy all customers when they are embodied; in addition, none of these inventions are capable of providing a moistureproof and dustproof effect simply by the addition of the antibacterial substances. [0007] Accordingly, there is a need for providing solutions to the highly demanded fabric functions. SUMMARY OF THE INVENTION [0008] It is therefore an objective of the present invention to provide a fabric having a three-layered structure for satisfying the demand for a moistureproof, dustproof, and antibacterial function. The three-layered structure is consisted of a fiber substrate, a parylene layer, and an antibacterial layer, wherein the fiber substrate is the fiber part of the fabric, the parylene layer is capable of providing a moistureproof and dustproof effect as well as preventing the fiber substrate from being catalyzed by photocatalyst and decomposed thereby, and the antibacterial layer, which comprises nano-photocatalyst and/or nano-silver particles, is used to kill pathogenic germs. [0009] It is another object of the present invention to provide a method of treating a fabric; the method forms a parylene layer on the fabric by means of chemical vapor deposition in the beginning and forms an antibacterial layer thereon afterwards. [0010] It is still another object of the present invention to provide a display having a fabric cover, mainly comprising a display part and a fabric covered the display part, said fabric further comprising a fiber substrate, a parylene layer formed on the fiber substrate, and an antibacterial layer formed on the parylene layer. [0011] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is an illustrative diagram showing a partially enlarged structure of the fabric of this invention. [0013] FIG. 2 is a flowchart of the method of this invention. [0014] FIG. 3 is an illustrative diagram of the display having a cover of this invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0015] Referring to FIG. 1 , an illustrative diagram showing a partially enlarged structure of the fabric 10 of this invention. The fabric 10 of this invention mainly comprises a three-layered structure consisting of a fiber substrate 11 , a parylene layer 13 , and an antibacterial layer 15 , wherein the parylene layer 13 is formed on the fiber substrate 11 , and the antibacterial layer 15 is formed on the parylene layer 13 . [0016] It is appreciated that in all of the above aspects of the invention, the fabric 10 used by this invention may have a wide range. For example, it may be, but not limited to, fuzz, non-woven, knitting cloth, flexible cloth, twill, lycra, jacquard, nylon, artificial silk, waterproof cloth, flannelette, suede, elastic fiber, et cetera. Also, it may be artificial fiber, natural fiber, or a mixture thereof. [0017] The parylene layer 13 mainly comprises a polymer having a skeletal basis identical to p-xylene or its derivatives. The polymer may be parylene N, parylene C, parylene N, et cetera. In addition, the parylene layer 13 is transparent layer and has low permeability; thus, the parylene layer 13 may demonstrate a desirable anti-mold property and a dustproof, waterproof protection effect with a low coefficient of friction, enabling it to be used as a protective layer to block off moisture and dust. [0018] In the antibacterial layer 15 exists more than one bactericidal ingredient. For example, the bactericidal ingredient may be a silver particle or photocatalyst capable of killing germs. Preferably, the bactericidal ingredient has a diameter less than 100 nanometers (nm). Since the techniques for pulverizing silver particles or photocatalyst into nano-particles, such as mechanical polishing or chemical synthesis, are already known, further elaboration is omitted hereby. [0019] Moreover, the photocatalyst may also be a metal oxide such as titanium dioxide, zinc oxide, tin dioxide, et cetera, as well as a sulfide like cadmium sulfide, zinc sulfide, et cetera. The photocatalyst may carry out a catalysis reaction after receiving light with specific wavelength/energy, and its amount remains the same after the reaction. [0020] Refer to FIG. 2 for a flowchart of the method of this invention. Basically, the method of the present invention may be divided into the following steps: [0021] 101 : Vaporizing parylene precursors. [0022] The powder of parylene precursors is vaporized in vacuum at a temperature of 150° C. In this invention, parylene precursors may be substituted or unsubstituted p-xylene dimers, such as mono-substituted or di-substituted chloro-p-xylene dimers. [0023] 102 : Pyrolyzing the vaporized parylene precursors to form parylene monomers. [0024] After the vaporization, the parylene precursors are treated at a temperature of 650° C. for pyrolyzing them into p-xylene monomers. Similarly, the p-xylene monomers may also be substituted or unsubstituted p-xylene ones, such as mono-substituted or di-substituted chloro-p-xylene monomers. [0025] 103 : Polymerizing the parylene monomers to form a parylene layer on the fabric. [0026] After the pyrolysis, the gas containing the p-xylene monomers is directed into a coating chamber with the presence of the fabric. At ambient temperature, the gas of p-xylene monomers will gradually deposit onto the fabric and become polymerized, forming a thin film of parylene. Depending on the precursors used before the reaction, parylene formed by the method of the present invention may vary. For instance, if the precursors used at the beginning of the reaction are p-xylene dimers mono-substituted by chlorine, the resulted compound is parylene C; if the precursors used at the beginning of the reaction are p-xylene dimers di-substituted by chlorine, the resulted compound is parylene D; if the precursors used at the beginning of the reaction are unsubstituted p-xylene dimers, the resulted compound will be parylene N. [0027] 104 : Forming an antibacterial layer on the parylene layer. [0028] Once coated by the parylene layer, the fabric becomes dustproof and moistureproof. However, in order to further furnish the fabric with an antibacterial function, an antibacterial layer needs to be formed on the parylene layer. The major ingredient of the antibacterial layer may be nano-silver particles and/or nano-photocatalyst. To form the antibacterial layer, a suspension containing nano-silver particles and/or nano-photocatalyst is prepared beforehand; then the suspension is applied onto the parylene layer by spraying, soaking, spreading, or vapor deposition. If the antibacterial layer contains both nano-silver particles and nano-photocatalyst, the bactericidal capability may be sustained by the coordination of mutual characteristics under light and dark conditions. [0029] To have a deeper insight of the technical features of the present invention, two examples are disclosed hereafter: EXAMPLE 1 [0030] By the use of above-mentioned vapor deposition, a parylene layer with a thickness between 1 to 20 micrometers (μm) is formed on the surface of fuzz cloth, said parylene mainly containing parylene N. In the meantime, a suspension for forming an antibacterial layer is prepared by adding silver particles into titanium dioxide powder to form a mixture of 25% by weight, where said silver particles have a diameter between 60 to 80 nm and a concentration of 2% to 5% by weight, and said titanium dioxide has a diameter between 15 to 25 nm and a concentration of 95% to 98% by weight. The preparation is completed by the addition of solvent into the mixture followed by well mixing. In this embodiment, the solvent may be but not limited to alcohol, acetone, xylene, or toluene. After that, the suspension is applied onto the parylene layer by spraying, soaking, spreading, or vapor deposition uniformly so as to form a 0.01 to 5 μm antibacterial layer. EXAMPLE 2 [0031] By the use of above-mentioned vapor deposition, a parylene layer with a thickness between 1 to 20 μm is formed on the surface of fuzz cloth, said parylene mainly containing parylene N. In the meantime, a suspension for forming an antibacterial layer is prepared by adding silver particles into zinc oxide powder to form a mixture of 25% by weight, where said silver particles have a diameter between 60 to 80 nm and a concentration of 2% to 5% by weight, and said zinc oxide has a diameter between 15 to 25 nm and a concentration of 95% to 98% by weight. The preparation is completed by the addition of solvent into the mixture followed by well mixing. In this embodiment, the solvent may be but not limited to alcohol, acetone, xylene, or toluene. After that, the suspension is applied onto the parylene layer by spraying, soaking, spreading, or vapor deposition uniformly so as to form a 0.01 to 5 μm antibacterial layer. [0032] Finally, turn to FIG. 3 for an illustrative diagram of a display 30 having a fabric cover of this invention. As shown, the display 30 mainly comprises a display part 20 and a fabric 10 covered thereon. The fabric 10 has a three-layered structure: a fiber substrate, a parylene layer, and an antibacterial layer. Thus, the fabric 10 not only furthers the appearance and design of the display part 20 but also provides a dustproof, moisture proof, and antibacterial function. Also, it is appreciated that in all of the above aspects of the invention, the display part 20 may be, but not limited to, a CRT display as well as a LCD display or a plasma display. [0033] Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
The present invention relates to a fabric having a three-layered structure: a fiber substrate, a parylene layer, and an antibacterial layer. The fiber substrate is the fiber part of the fabric; the parylene layer is capable of providing a moistureproof and dustproof effect as well as preventing the fiber substrate from being catalyzed by photocatalyst and decomposed thereby; the antibacterial layer, which comprises nano-photocatalyst and/or nano-silver particles, is used to kill pathogenic germs.
8
RELATED APPLICATIONS [0001] This application is a Continuation of U.S. patent application Ser. No. 11/858,140 filed on Sep. 20, 2007. BACKGROUND [0002] Distributed systems, such as networked computers, may need to know each other's state during communications. This typically requires that two systems communicate sequentially rather than simultaneously. If both systems send messages to each other simultaneously (or non-sequentially) resulting in crisscrossed messages, a race condition can develop which can lead to divergent and corrupted state information. SUMMARY [0003] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later. [0004] The present examples provide technologies for ordered message delivery that avoid message races or crisscrosses between communicating nodes. For example, if Node A sends message 3 towards Node B and, shortly thereafter, Node B sends message X to Node A, Node A would like to know whether or not message X reflects Node B's state after receiving message 3. If Node B received message 3 prior to sending message X, then proper state may be maintained between the nodes. But if messages 3 and X crisscrossed, or if message 3 was never properly received by Node B, then the state between the nodes may be corrupt. Technologies, systems, and methods are provided to avoid such corruption. [0005] Many of the attendant features will be more readily appreciated as the same become better understood by reference to the following detailed description considered in connection with the accompanying drawings. DESCRIPTION OF THE DRAWINGS [0006] The present description will be better understood from the following detailed description considered in connection with the accompanying drawings, wherein: [0007] FIG. 1 is a block diagram showing two example crisscross cancellation protocol-enabled nodes that are communicatively coupled. [0008] FIG. 2 is a block diagram showing an example crisscross cancelation protocol (“C3P”) message including an example C3P header. [0009] FIG. 3 is a block diagram showing an example crisscross cancellation protocol state diagram. [0010] FIG. 4 is a block diagram showing an example method for initializing a crisscross cancellation protocol instance and for sending a message. [0011] FIG. 5 is a block diagram showing an example method for processing a crisscross cancellation protocol message and detecting a message crisscross. [0012] FIG. 6 is a timing diagram showing an example of ordered message transmissions between two example nodes. [0013] FIG. 7 is a block diagram showing an example method for processing a crisscross cancellation protocol message while in a race fix state. [0014] FIG. 8 is a timing diagram, an extension of the timing diagram of FIG. 6 , showing an example of a message crisscross and a subsequent recovery. [0015] FIG. 9 is a block diagram showing an example computing environment in which the technologies described herein may be implemented. [0016] Like reference numerals are used to designate like parts in the accompanying drawings. DETAILED DESCRIPTION [0017] The detailed description provided below in connection with the accompanying drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present examples may be constructed or utilized. The description sets forth at least some of the functions of the examples and/or the sequence of steps for constructing and operating examples. However, the same or equivalent functions and sequences may be accomplished by different examples. [0018] Although the present examples are described and illustrated herein as being implemented in a computing and networking environment, the environment described is provided as an example and not a limitation. As those skilled in the art will appreciate, the present examples are suitable for application in a variety of different types of computing and networking environments. [0019] FIG. 1 is a block diagram showing two example crisscross cancellation protocol-enabled nodes that are communicatively coupled. Node A and Node B are coupled as indicated by line 190 , which may be any type of coupling, connection, communications link, network, or the like. Each node includes an example application, such as applications 110 a and 110 b , which may be any program, system, device, software, device driver, firmware, or the like that may benefit from a crisscross cancellation protocol. Applications 110 a and 110 b may or may not be the same. Applications 110 a and 110 b typically send and receive messages via a crisscross cancellation protocol (“C3P”) layer, such as C3Ps 120 a and 120 b . The crisscross cancellation protocol maintains appropriate state information via state variables such as variables 121 a - 124 a . A crisscross cancellation protocol typically makes use of a transport, such as transports 130 a and 130 b , to send and receive C3P messages over some form of communications link. [0020] The state fields or variables typically maintain the state of the C3P. Each C3P module or instance of the C3P includes: a counter, such as counter state variables 121 a and 121 b ; a nonce, such as nonce state variables 122 a and 122 b ; a remote counter, such as remote counter state variables 123 a and 123 b ; and a remote nonce, such as remote nonce state variables 124 a and 124 b . In one example, each of these state variables is a 64-bit number. [0021] The nonce state variable (i.e., 122 a ) typically uniquely identifies the current C3P session. A C3P session is typically established when a C3P layer is initialized. A new instance of the C3P layer is typically established each time a C3P-enabled node needs to communicate with a new C3P-enabled node (for example, one that it has not previously communicated with). Generally, each time a C3P layer is initialized a new nonce is generated. [0022] The remote nonce state variable (i.e., 124 a ) is typically used to record the nonce of a remote node (that is, the remote node's C3P layer) as indicated by the header of the last valid C3P message received from the remote node. [0023] The term “nonce” as used herein refers to a cryptographic random nonce, a counter or random or pseudo-random number that is unlikely to be reused. Such a nonce is generally used by C3P to identify each session uniquely from any other session. Thus, in the event of a node crash or the like, the next time the C3P is initialized a new and unique nonce is established indicating a new and unique C3P session. [0024] The counter state variable (i.e., 121 a ) is typically a monotonically increasing variable that increments by one for each message sent, or a value identifying the last message sent. In one example, the counter is incremented each time a message is sent. [0025] The remote counter state variable (i.e., 123 a ) is typically used to record the counter of a remote node (that is, the remote node's C3P layer) as indicated by the header of the last valid C3P message received from the remote node. [0026] In general, an application passes a message to be sent to another node down to the C3P layer, the C3P layer typically adds a C3P header (as described in connection with FIG. 1 ), buffers the message in a send buffer, and passes the message to the transport which sends the message over the network to the target node. Each C3P layer typically buffers a single outgoing message in a send buffer. [0027] Upon receiving a valid C3P message, the message is stored in a C3P receive buffer after the target node's transport passes the C3P message up to the C3P layer. In one example, the receive buffer stores one or more incoming messages. The C3P layer verifies the messages are valid, removes the C3P header, and passes the message up to a corresponding application. In one example, once the application is done processing the received message, it instructs the C3P layer to empty this message from the receive buffer. In this example, the C3P layer will not send a message until the receive buffer is empty, as doing so would be equivalent to a message crisscross, with the application sending a new message without having processed a previously received message. [0028] The two communicating C3P layers interoperate to provide ordered message delivery for the applications and to avoid message races or crisscrosses. The term “message race” or “message crisscross” or “crisscross” as used herein refers to the situation when a first node sends a message to a second node and, before the second node receives the message from the first node, the second node sends a message to the first node. Such a situation results in a message crisscross or message race condition. This situation is described in more detail in connection with FIG. 8 . [0029] As used herein, the term “node” refers to any computer system, device, or process that is uniquely addressable, or otherwise uniquely identifiable, over a network or the like, and that is operable to communicate with other nodes over the network. For example, and without limitation, a node may be a personal computer, a server computer, a hand-held or laptop device, a tablet device, a multiprocessor system, a microprocessor-based system, a set top box, a consumer electronic device, a network PC, a minicomputer, a mainframe computer, a uniquely-identifiable software application, or the like. One example of a node such as Node A and Node B, in the form of computer system 900 , is set forth herein below with respect to FIG. 9 . [0030] FIG. 2 is a block diagram showing an example crisscross cancelation protocol (“C3P”) message 200 including an example C3P header 210 . The C3P message 200 is typically comprised of an application message (a message, packet, data, or the like provided by an application) in the message field 220 and a C3P header 210 . In one example, C3P header 210 includes state information in four fields: nonce 211 , remote nonce 212 , counter 213 , and remote counter 214 . In this example, the state values are 64-bit numbers. Nonce 211 and counter 213 values are typically taken from the sending C3P's corresponding state variables each time a message is sent. Remote nonce 212 and remote counter 214 values are typically taken from the sending C3P's remote nonce and remote counter state variables, the values of which are typically obtained from the header of the last valid C3P message received from the remote node. A C3P ping message is a version of C3P message 200 that does not include application message 220 . [0031] FIG. 3 is a block diagram showing an example crisscross cancellation protocol state diagram 300 . A particular C3P instance generally transitions between two states: C3P normal state 310 and C3P race fix state 320 . Once the C3P instance is successfully initialized, it typically enters C3P normal state 310 . Each time a normal (non-C3P ping) C3P message is sent, the C3P transitions back into the C3P normal state as indicated by arrow 330 . The C3P remains in the C3P normal state 330 until a C3P message crisscross is detected. If a C3P message crisscross is detected (as described in connection with FIG. 5 ), the C3P transitions into the C3P race fix state 320 as indicated by arrow 340 . The C3P remains in the C3P race fix state 320 until a C3P message is received that is not a message crisscross. Each time any C3P message is received that has crisscrossed with another message, the C3P transitions back into the C3P race fix state 320 as indicated by arrow 350 . When an in-order C3P message (either a C3P ping or a C3P message that does include an application message) is received or other appropriate conditions are met as described in connection with FIG. 7 , the C3P transitions into the C3P normal state 310 as indicated by arrow 360 . [0032] FIG. 4 is a block diagram showing an example method 400 for initializing a crisscross cancellation protocol instance and for sending a message. C3P initialization includes the steps indicated by blocks 410 and 420 . Each time a hosting node starts a C3P instance the initialization steps are performed. This generally includes each time the node starts a new C3P instance to communicate with a particular new remote node, and each time the node restarts during a C3P session, such as a reboot or a crash restart. [0033] Block 410 indicates initializing the C3P's nonce state variable, as described in connection with FIG. 1 . This is typically done by generating a new nonce value. In one example, a nonce is generated as a random number which is typically different than a previous nonce. Once the nonce state variable is initialized, method 400 typically continues at block 420 . [0034] Block 420 indicates initializing the C3P's counter state variable, as described in connection with FIG. 1 . This is typically done by generating a new counter value. In one example, the counter is initialized to zero (0). Once the counter state variable is initialized, C3P initialization is typically complete and method 400 typically continues at block 430 . [0035] Block 430 typically indicates waiting for an application message to send. Once the C3P is initialized, it waits for a message to be sent. Messages are typically provided by an application or the like. Once a message is available to be sent, method 400 typically continues at block 440 . [0036] Block 440 typically indicates incrementing the counter state variable, as described in connection with FIG. 1 . The counter state variable may be incremented by one or more. Once the counter state variable has been incremented, method 400 typically continues at block 450 . [0037] Block 450 typically indicates formatting and sending a C3P message. Formatting is typically performed by adding a C3P header to the message provided by the application (see description for block 430 ). The C3P header and message are typically constructed as described in connection with FIG. 2 . In one example, the C3P message is sent by providing it to a transport as described in connection with FIG. 1 . Once the message is sent, method 400 typically continues at block 430 . [0038] FIG. 5 is a block diagram showing an example method 500 for processing a crisscross cancellation protocol message and detecting a message crisscross. Method 500 is typically performed by a C3P instance receiving a C3P message while in the C3P normal state as described in connection with FIG. 3 . In general, method 500 compares state information in the incoming message's header with state information stored in the C3P instance receiving the message, as described in connection with FIG. 1 . [0039] Block 510 typically indicates receiving a C3P message. Such a message typically includes a C3P header including state information as described in connection with FIG. 2 . Once a message is received, method 500 typically continues at block 520 . [0040] Block 520 typically indicates determining if the nonce value of the incoming message's header is correct. In one example, the value in the nonce field of the incoming message's header (i.e., item 211 , FIG. 2 ) is compared with the value stored in the remote nonce field of the receiving C3P instance's state information (i.e., item 124 a , FIG. 1 ). If the two values do not match (e.g., are not equal), then the receiving C3P instance assumes that the sending C3P instance has crashed since the last message received. If the two values do not match, method 500 typically continues at block 530 . Otherwise, method 500 typically continues at block 550 . [0041] Block 530 typically indicates invalidating the receiving C3P instance's state information. In one example this is done by setting each of the remote state values (i.e., items 123 a - 124 a , FIG. 1 ) to zero (0). Once the state information has been invalidated, the application is typically made aware that the remote C3P instance has experienced a crash, and then method 500 typically continues at block 540 . [0042] Block 540 typically indicates setting the receiving C3P instance's remote nonce field (i.e., item 124 a , FIG. 1 ) to the value in the nonce field of the incoming message (i.e., item 211 , FIG. 2 ). Once the remote nonce state value is set, method 500 continues at block 550 . [0043] Block 550 typically indicates determining if the counter value of the incoming message's header is correct. In one example, the value in the counter field of the incoming message's header (i.e., item 213 , FIG. 2 ) is strictly greater than the value stored in the remote counter field of the receiving C3P instance's state information (i.e., item 123 a , FIG. 1 ). If the incoming counter is not greater, then the receiving C3P instance assumes that it has already received the incoming message or a later message. If the incoming counter is not greater, then method 500 typically continues at block 552 . Otherwise, method 500 typically continues at block 560 . [0044] Block 552 typically indicates dropping the incoming message because it was either already received or because a later message was already received (see block 550 ). Once the incoming message is dropped, method 500 typically continues at block 510 . [0045] Block 560 typically indicates setting the receiving C3P instance's remote counter field (i.e., item 123 a , FIG. 1 ) to the value in the counter field of the incoming message (i.e., item 213 , FIG. 2 ). Once the remote counter state value is set, method 500 continues at block 570 . [0046] Block 570 typically indicates determining if the remote counter value and remote nonce value of the incoming message's header are correct. In one example, the value in the remote counter field of the incoming message's header (i.e., item 214 , FIG. 2 ) matches (e.g., is equal to) the value stored in the counter field of the receiving C3P instance's state information (i.e., item 121 a , FIG. 1 ) and the value in the remote nonce field of the incoming message's header (i.e., item 212 , FIG. 2 ) is either zero or matches (e.g., is equal to) the value stored in the nonce field of the receiving C3P instance's state information (i.e., item 122 a , FIG. 1 ). If the incoming remote counter does not match, or if the incoming remote nonce is neither zero nor matching, then the receiving C3P instance assumes that one or more messages have crisscrossed. If the incoming remote counter is not matching, or if the incoming remote nonce is neither zero nor matching, then method 500 typically continues at block 572 . Otherwise, method 500 typically continues at block 580 . [0047] Block 572 typically indicates the receiving C3P instance entering the C3P race fix state as described in connection with FIG. 3 . Entering the C3P race fix state typically includes dropping the incoming message. Processing while in the C3P race fix state proceeds as described in connection with FIG. 7 . [0048] Block 580 typically describes passing the incoming message up to a receiving application. At this point the incoming message is determined to be valid. In one example, the C3P header is stripped from the message before it is passed up. Once the message is passed, method 500 typically continues at block 510 . [0049] FIG. 6 is a timing diagram 600 showing an example of ordered message transmissions between two example nodes. Arrow 610 is a timeline for Node A and arrow 611 is a corresponding timeline for Node B. State block 612 shows the example initial state of Node A and state block 613 shows the example initial state of Node B at the beginning of the timelines. State blocks 612 , 613 , and the like, and their included fields, correspond to those described in connection with FIG. 1 . In particular, field 612 a corresponds to field 121 a of FIG. 1 ; field 612 b corresponds to field 123 a of FIG. 1 ; field 6112 c corresponds to field 122 a of FIG. 1 ; and field 612 d corresponds to field 124 a of FIG. 1 . The values for the various state fields are examples only and may be any appropriate values in practice. Each node is typically initialized to the C3P normal state as described in connection with FIG. 3 and typically operates according to method 500 described in connection with FIG. 5 . In one example, the state fields support 64-bit values and may be initialized as shown in Table A and Table B herein below: [0000] TABLE A Node A Initial State: Nonce 0x1234567812345678 Counter 0 Remote Nonce 0x0 Remote Counter 0 [0000] TABLE B Node B Initial State: Nonce 0x8765432187654321 Counter 0 Remote Nonce 0x0 Remote Counter 0 [0050] As shown in tables A and B, examples of the initial states of Nodes A and B, each node knows its own nonce, but not the other node's nonce (as indicated by the initial value of zero shown in hexadecimal (0x0) in the Remote Nonce fields). Further, in their initial states, each node knows its own counter (which may be initialized to zero as shown), but not the other node's counter (as indicated by the initial value of zero (0) in the remote counter fields). Nonce fields may be initialized with random values. In other examples, initial values other than zero may be used and/or initial values of the other node may be known. [0051] Timing diagram 600 shows Node B sending a first message to Node A, as indicated by arrow and message header 620 . The message header includes the nonce value of Node B (N=98), the nonce of node A (RN=0, currently unknown by Node B), the incremented counter value of Node B (C=11, incremented from C=10 of state 613 prior to sending message 620 ), and the counter value of Node A (RC=0, currently unknown by Node B). State block 615 indicates the state of Node B after sending message 620 . [0052] Upon receiving message 620 , Node A updates its state with the information from the header of message 620 , as indicated by state block 614 . At this point, Node A knows the nonce of Node B (RN=98) and the message counter of Node B (RC=11), and state 614 is updated to indicate such. Node A may know message 620 is a first message from Node B because Node A's state information for Node B (remote nonce and remote counter) was set to the initial state (zero) when message 620 was received. [0053] Per timing diagram 600 , Node A now sends a message to Node B, as indicated by arrow and message header 630 . The message header includes the nonce value of Node A (N=12), the incremented counter value of Node A (C=1, incremented from C=0 of state 612 prior to sending message 630 ), the nonce value of node B (RN=98, known by Node A via message 620 ), and the counter value of Node B (R=11, known by Node A via message 620 ). State block 616 indicates the state of Node A after sending message 630 . [0054] Upon receiving message 630 , Node B updates its state with the information from the header of message 630 , as indicated by state block 617 . At this point, Node B knows the nonce of Node A (RN=12) and the message counter of Node A (RC=1), and state 617 is updated to indicate such. Node B may know message 630 is a first message from Node A because Node B's state information for Node A (remote nonce and remote counter) was set to the initial state (zero) when message 630 was received. [0055] Per timing diagram 600 , Node B now sends a second message to Node A, as indicated by arrow and message header 640 . The message header includes the nonce value of Node B (N=98), the incremented counter value of Node B (C=12, incremented from C=11 of state 617 prior to sending message 640 ), the nonce value of Node A (RN=12, known by Node B via message 630 ) and the counter value of Node A (RC=1, known by Node B via message 630 ). State block 619 indicates the state of Node B after sending message 640 . [0056] Upon receiving message 640 , Node A determines that its state values for Node B (remote nonce and remote counter) are not set to the initial values. Therefore, Node A verifies that the nonce value in the message header 640 from Node B (N=98) matches that of its state 616 for Node B (RN=98). If there is a match, then Node A knows that the C3P session of Node B has not reset since the last message received from Node B. Node A further verifies that the counter value in message header 640 from Node B (C=12) is greater than that of its state 616 for Node B (RC=11). If the counter of the incoming message is greater than that of Node A's state for Node B, then Node A knows that message 640 , or a later message, has not already been received. Node A further verifies that the remote counter value in message header 640 from Node B (RC=1) matches that of its state 616 for Node A's counter (C=1). If there is a match, then Node A knows that Node B did not send message 640 prior to receiving message 630 from Node A—that is, there was no message crisscross. If the nonce and counter of message 640 are valid and there was no message crisscross, then Node A updates its state with the information from the header of message 640 , as indicated by state block 618 . Other ordered messages may be sent between Nodes A and B in like manner. [0057] FIG. 7 is a block diagram showing an example method 700 for processing a crisscross cancellation protocol message while in a race fix state. Method 700 is typically performed by a C3P instance receiving a C3P message while in the C3P race fix state as described in connection with FIG. 3 . In general, method 700 compares state information in the incoming message's header with state information stored in the C3P instance receiving the message, as described in connection with FIG. 1 . [0058] Block 710 typically indicates the C3P instance receiving an incoming C3P message. Such an incoming message may be a C3P message, as described in connection with FIG. 2 , or a C3P ping message, as described in connection with FIGS. 2 and 8 . When such a message arrives, it is typically buffered in a single-message receive buffer. When a message arrives, method 700 typically continues at block 740 . Until a message arrives, method 700 typically continues at block 720 . [0059] Block 720 typically indicates determining if it is time to send a C3P ping message. In one example, ping messages are sent while in the C3P race fix state at intervals based on a back-off algorithm, such as starting with an interval of 50 milliseconds and doubling the interval with each ping that does not result in a return to the C3P normal state. When it is time to send a ping message, method 700 typically continues at block 730 . Otherwise, method 700 typically continues at block 710 waiting for an incoming message. [0060] Block 730 typically indicates sending a C3P ping message. This typically involves constructing the message header based on current state information as described in connection with FIG. 2 . Once the ping message has been sent, method 700 typically continues with block 710 . [0061] Block 740 typically indicates validating the incoming message. In one example, this is done by checking the message header values against the state variable of the C3P instance as described in connection with blocks 520 through 570 of FIG. 5 . If any of the incoming message's header values are incorrect, method 700 typically continues at block 742 . Otherwise, method 700 typically continues at block 744 . [0062] Block 742 typically indicates dropping the incoming message. Once the incoming message is dropped, method 700 typically continues at block 710 . [0063] Block 744 typically indicates updating the C3P instance's state variables based on the incoming message's header values. In one example, this is done by checking the message header values against the state variable of the C3P instance as described in connection with blocks 520 through 570 of FIG. 5 . Once the state variables are updated, method 700 typically continues at block 750 . [0064] Block 750 typically indicates determining if a buffered message is present in the send buffer and an incoming message is a ping message. If a buffered message is present in the send buffer and the incoming message is a ping message, method 700 typically continues at block 760 . Otherwise, method 700 typically continues at block 770 . [0065] Block 760 typically indicates sending the message in the send buffer. Generally this message is a non-ping message that may have been previously sent, but being in the race fix state and the receipt of a ping message results in resending the buffered message. Once the buffered message has been sent, method 700 typically continues at block 770 . [0066] Block 770 typically indicates the C3P instance transitioning from the C3P race fix state to the C3P normal state. Once in the C3P normal state processing typically continues as described in connection with FIG. 5 . [0067] FIG. 8 is a timing diagram 600 b , an extension of timing diagram 600 of FIG. 6 , showing an example of a message crisscross and a subsequent recovery. Arrow 610 b is a continuation of timeline arrow 610 for Node A and arrow 611 b is a continuation of timeline arrow 611 for Node B. State block 812 represents that same point on timeline 610 / 610 b as state block 618 of FIG. 6 . State block 813 represents the same point on timeline 611 / 611 b as state block 619 of FIG. 6 . The example message crisscross is shown between messages 820 and 830 . [0068] Per timing diagram 600 b , Node A sends a message to Node B (as indicated by arrow and message header 820 ) but Node B sends a message to Node A (as indicated by arrow and message header 830 ) prior to receiving message 820 from Node A. This results in a message crisscross as opposed to ordered messaging. [0069] Upon receiving message 820 , Node B detects that the remote counter value in message header 820 from Node A (RC=12) does not match that of its state information 815 for Node B's counter (C=13). In this example, this is because of the crisscross of messages 820 and 830 —that is, nodes A and B each sent a message to each other prior to receiving the other's message, resulting in each node's state information becoming unsynchronized with that of the other. Similarly, upon receiving message 830 , Node A detects that the remote counter value in message header 830 from Node B (RC=1) does not match that of its state information 814 for Node A's counter (C=2), a result of the message crisscross. In this example, crisscrossed messages 820 and 830 are typically dropped by the receiving nodes and each node enters the C3P race fix state as described in connection with FIG. 3 . [0070] Per timing diagram 600 b , Node A then sends a C3P ping message to Node B, as indicated by dashed arrow and message header 840 . A C3P ping message is typically a message such as C3P message 200 of FIG. 2 wherein the application message 220 portion is not included. Such a ping message thus includes a message header, such as C3P header 210 of FIG. 2 , but no application message. Alternatively or additionally, Node B may send a ping message to Node A as it is also in the C3P race fix state. A ping message generally includes current nonce and counter data thus providing the receiving node with the sending node's latest state information. Each such ping message communicates, “your turn to send,” to the receiving node. [0071] Upon receiving ping message 840 , Node B compares the incoming message's header information to its state information 817 and verifies that the incoming message's nonce field (N=12) matches its remote nonce state value (RN=12), that the incoming message counter (C=3) is greater than its remote counter state value (RC=2), and that the incoming message's remote counter value (RC=13) matches its counter state value (C=13). Thus Node B verifies that ping message 840 is valid, updates its state information 819 based on the incoming ping message, and transitions from the C3P race fix state to the C3P normal state. Further, Node B re-sends the message in its send buffer, message 830 , as indicated by arrow and message header 850 . [0072] Upon receiving message 850 , Node A compares the incoming message's header information to its state information 818 and verifies the message is valid. Because incoming message 850 is valid, Node A transitions from the C3P race fix state to the C3P normal state. Because message 850 is valid and because it is not a C3P ping message, Node A recognizes that application message 820 must be deleted from the send buffer (only one message from the pair that led to the crisscross may be delivered, and the buffered message on Node A in this example is the one that must not be delivered). [0073] At this point both Node A and Node B have successfully transitioned from the C3P race fix state back to the C3P normal state and ordered message communication can continue. [0074] Alternative methods for exiting the race fix state may also be employed. For example, a node in the C3P race fix state may exit the race fix state after having sent a specified number of ping messages. Such a change may have the negative consequence of delaying the resumption of ordered message communication, but may have the positive consequence of conserving network resources. As a second example, instead of sending the C3P ping messages once a crisscross has been detected, each node may instead send their normal messages with updated counter values. Such a change may have the negative consequence of using significantly more network resources if further message crisscrosses occur (because application messages may be much larger than C3P ping messages), but it may have the positive consequence of avoiding an extra message delay if no further message crisscrosses occur. As a third example, the nonces between a node A and a node B that are communicating may be collapsed into a single nonce by using a handshake analogous to the SYN/SYN-ACK handshake in the Transmission Control Protocol (“TCP”); this may have the positive consequence of reducing the state associated with the C3P layer and the C3P header but may have the negative consequence of requiring additional messages when two nodes first communicate via C3P. [0075] FIG. 9 is a block diagram showing an example computing environment 900 in which the technologies described herein may be implemented. A suitable computing environment may be implemented with numerous general purpose or special purpose systems. Examples of well known systems may include, but are not limited to, cell phones, personal digital assistants (“PDA”), personal computers (“PC”), hand-held or laptop devices, microprocessor-based systems, multiprocessor systems, servers, workstations, consumer electronic devices, set-top boxes, and the like. [0076] Computing environment 900 typically includes a general-purpose computing system in the form of a computing device 901 coupled to various components, such as peripheral devices 902 , 903 , 904 and the like. System 900 may couple to various other components, such as input devices 903 , including voice recognition, touch pads, buttons, keyboards and/or pointing devices, such as a mouse or trackball, via one or more input/output (“I/O”) interfaces 912 . The components of computing device 901 may include one or more processors (including central processing units (“CPU”), graphics processing units (“GPU”), microprocessors (“μP”), and the like) 907 , system memory 909 , and a system bus 908 that typically couples the various components. Processor 907 typically processes or executes various computer-executable instructions to control the operation of computing device 901 and to communicate with other electronic and/or computing devices, systems or environment (not shown) via various communications connections such as a network connection 914 or the like. System bus 908 represents any number of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a serial bus, an accelerated graphics port, a processor or local bus using any of a variety of bus architectures, and the like. [0077] System memory 909 may include computer readable media in the form of volatile memory, such as random access memory (“RAM”), and/or non-volatile memory, such as read only memory (“ROM”) or flash memory (“FLASH”). A basic input/output system (“BIOS”) may be stored in non-volatile or the like. System memory 909 typically stores data, computer-executable instructions and/or program modules comprising computer-executable instructions that are immediately accessible to and/or presently operated on by one or more of the processors 907 . [0078] Mass storage devices 904 and 910 may be coupled to computing device 901 or incorporated into computing device 901 via coupling to the system bus. Such mass storage devices 904 and 910 may include non-volatile RAM, a magnetic disk drive which reads from and/or writes to a removable, non-volatile magnetic disk (e.g., a “floppy disk”) 905 , and/or an optical disk drive that reads from and/or writes to a non-volatile optical disk such as a CD ROM, DVD ROM 906 . Alternatively, a mass storage device, such as hard disk 910 , may include non-removable storage medium. Other mass storage devices may include memory cards, memory sticks, tape storage devices, and the like. [0079] Any number of computer programs, files, data structures, and the like may be stored in mass storage 910 , other storage devices 904 , 905 , 906 and system memory 909 (typically limited by available space) including, by way of example and not limitation, operating systems, application programs, data files, directory structures, computer-executable instructions, and the like. [0080] Output components or devices, such as display device 902 , may be coupled to computing device 901 , typically via an interface such as a display adapter 911 . Output device 902 may be a liquid crystal display (“LCD”). Other example output devices may include printers, audio outputs, voice outputs, cathode ray tube (“CRT”) displays, tactile devices or other sensory output mechanisms, or the like. Output devices may enable computing device 901 to interact with human operators or other machines, systems, computing environments, or the like. A user may interface with computing environment 900 via any number of different I/O devices 903 such as a touch pad, buttons, keyboard, mouse, joystick, game pad, data port, and the like. These and other I/O devices may be coupled to processor 907 via I/O interfaces 912 which may be coupled to system bus 908 , and/or may be coupled by other interfaces and bus structures, such as a parallel port, game port, universal serial bus (“USB”), fire wire, infrared (“IR”) port, and the like. [0081] Computing device 901 may operate in a networked environment via communications connections to one or more remote computing devices through one or more cellular networks, wireless networks, local area networks (“LAN”), wide area networks (“WAN”), storage area networks (“SAN”), the Internet, radio links, optical links and the like. Computing device 901 may be coupled to a network via network adapter 913 or the like, or, alternatively, via a modem, digital subscriber line (“DSL”) link, integrated services digital network (“ISDN”) link, Internet link, wireless link, or the like. [0082] Communications connection 914 , such as a network connection, typically provides a coupling to communications media, such as a network. Communications media typically provide computer-readable and computer-executable instructions, data structures, files, program modules and other data using a modulated data signal, such as a carrier wave or other transport mechanism. The term “modulated data signal” typically means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communications media may include wired media, such as a wired network or direct-wired connection or the like, and wireless media, such as acoustic, radio frequency, infrared, or other wireless communications mechanisms. [0083] Power source 990 , such as a battery or a power supply, typically provides power for portions or all of computing environment 900 . In the case of the computing environment 900 being a mobile device or portable device or the like, power source 990 may be a battery. Alternatively, in the case computing environment 900 is a desktop computer or server or the like, power source 990 may be a power supply designed to connect to an alternating current (“AC”) source, such as via a wall outlet. [0084] Some mobile devices may not include many of the components described in connection with FIG. 9 . For example, an electronic badge may be comprised of a coil of wire along with a simple processing unit 907 or the like, the coil configured to act as power source 990 when in proximity to a card reader device or the like. Such a coil may also be configure to act as an antenna coupled to the processing unit 907 or the like, the coil antenna capable of providing a form of communication between the electronic badge and the card reader device. Such communication may not involve networking, but may alternatively be general or special purpose communications via telemetry, point-to-point, RF, IR, audio, or other means. An electronic card may not include display 902 , I/O device 903 , or many of the other components described in connection with FIG. 9 . Other mobile devices that may not include many of the components described in connection with FIG. 9 , by way of example and not limitation, include electronic bracelets, electronic tags, implantable devices, and the like. [0085] Those skilled in the art will realize that storage devices utilized to provide computer-readable and computer-executable instructions and data can be distributed over a network. For example, a remote computer or storage device may store computer-readable and computer-executable instructions in the form of software applications and data. A local computer may access the remote computer or storage device via the network and download part or all of a software application or data and may execute any computer-executable instructions. Alternatively, the local computer may download pieces of the software or data as needed, or process the software in a distributed manner by executing some of the instructions at the local computer and some at remote computers and/or devices. [0086] Those skilled in the art will also realize that, by utilizing conventional techniques, all or portions of the software's computer-executable instructions may be carried out by a dedicated electronic circuit such as a digital signal processor (“DSP”), programmable logic array (“PLA”), discrete circuits, and the like. The term “electronic apparatus” may include computing devices or consumer electronic devices comprising any software, firmware or the like, or electronic devices or circuits comprising no software, firmware or the like. [0087] The term “firmware” typically refers to executable instructions, code, data, applications, programs, or the like maintained in an electronic device such as a ROM. The term “software” generally refers to executable instructions, code, data, applications, programs, or the like maintained in or on any form of computer-readable media. The term “computer-readable media” typically refers to system memory, storage devices and their associated media, and the like. [0088] In view of the many possible embodiments to which the principles of the present invention and the forgoing examples may be applied, it should be recognized that the examples described herein are meant to be illustrative only and should not be taken as limiting the scope of the present invention. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and any equivalents thereto.
Technologies, systems, and methods for ordered message delivery that avoid message races or crisscrosses between communicating nodes. For example, if Node A sends message 3 towards Node B and, shortly thereafter, Node B sends message X to Node A, Node A would like to know whether or not message X reflects Node B's state after receiving message 3. If Node B received message 3 prior to sending message X, then proper state may be maintained between the nodes. But if messages 3 and X crisscrossed, or if message 3 was never properly received by Node B, then the state between the nodes may be corrupt. Technologies, systems, and methods are provided to avoid such corruption.
7
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of U.S. provisional patent application serial No. 60/238,496, filed Oct. 6, 2000, which is herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to optimizing production of hydrocarbon wells. More particularly, the invention relates to an auto-adjusting well control system for the operation of the well. More particularly still, the invention relates to optimizing the production of a hydrocarbon well intermitted by a plunger lift system or a gas lift system. 2. Description of the Related Art The production of fluid hydrocarbons from wells involves technologies that vary depending upon the characteristics of the well. While some wells are capable of producing under naturally induced reservoir pressures, more common are wells, which employ some form of an artificial lift production procedure. During the life of any producing well, the natural reservoir pressure decreases as gases and liquids are removed from the formation. As the natural downhole pressure of a well decreases, the wellbore tends to fill up with liquids, such as oil and water. In a gas well, the accumulated fluids block the flow of the formation gas into the borehole and reduce the output production from the well. To combat this condition, artificial lift techniques are used to periodically remove the accumulated liquids from these wells. The artificial lift techniques may include plunger lift devices and gas lift devices. Plunger lift production systems include the use of a small cylindrical plunger which travels through tubing extending from a location adjacent the producing formation in the borehole to surface equipment located at the open end of the borehole. In general, fluids which collect in the borehole and inhibit the flow of fluids out of the formation and into the well bore, are collected in the tubing. Periodically, the end of the tubing located at the surface is opened via a valve and the accumulated reservoir pressure is sufficient to force the plunger up the tubing. The plunger carries with it to the surface a load of accumulated fluids which are ejected out the top of the well. In the case of an oil well, the ejected fluids are collected as the production flow of the well. In the case of a gas well, the ejected fluids are simply disposed of, thereby allowing gas to flow more freely from the formation into the well bore and be delivered into a gas distribution system known as a sales line at the surface. The production system is operated so that after the flow of gas from the well has again become restricted due to the further accumulation of fluid downhole, the valve is closed so that the plunger falls back down the tubing. Thereafter, the plunger is ready to lift another load of fluids to the surface upon the re-opening of the valve. A gas lift production system is another type of artificial lift system used to increase a well's performance. The gas lift production system generally includes a valve system for controlling the injection of pressurized gas from a source external to the well, such as a compressor, into the borehole. The increased pressure from the injected gas forces accumulated formation fluid up a central tubing extending along the borehole to remove the fluids as production flow or to clear the fluids and restore the free flow of gas from the formation into the well. The gas lift production system may be combined with the plunger lift system to increase efficiency and combat problems associated with liquid fall back. The use of artificial lift systems results in the cyclical production of the well. This process, also generally termed as “intermitting,” involves cycling the system between an on-cycle and an off-cycle. During the off-cycle, the well is “shut-in” and not productive. Thus, it is desirable to maintain the well in the on-cycle for as long as possible in order to fully realize the well's production capacity. Historically, the intermitting process is controlled by pre-selected time periods. The timing technique provides for cycling the well between on and off cycles for a predetermined period of time. Deriving the time interval of these cycles has always been difficult because production parameters considered for this task are different in every well and the parameters associated with a single well change over time. For instance, as the production parameters change, a plunger lift system operating on a short timed cycle may lead to an excessive quantity of liquids within the tubing string, a condition generally referred to as a “loading up” of the well. This condition usually occurs when the system initiates the on-cycle and attempts to raise the plunger to the surface before a sufficient pressure differential has developed. Without sufficient pressure to bring it to the surface, the plunger falls back to the bottom of the wellbore without clearing the fluid thereabove. Thereafter, the cycle starts over and more fluids collect above the plunger. By the time the system initiates the on-cycle again, too much fluid has accumulated above the plunger and the pressure in the well is no longer able to raise the plunger. This condition causes the well to shut-in and represents a failure that may be quite expensive to correct. In contrast, a lift system that operates on a relatively long timed cycle may result in waste of production capacity. The longer cycle reduces the number of trips the plunger goes to the surface. Because production is directly related to the plunger trips, production also decrease when the plunger trips decrease. Thus, it is desirable to allow the plunger to remain at the bottom only long enough to develop sufficient pressure differential to raise the plunger to the surface. Improvements to the timing technique include changing the predetermined time period in response to the well's performance. For example, U.S. Pat. No. 4,921,048, incorporated herein by reference, discloses providing an electronic controller which detects the arrival of a plunger at the well head and monitors the time required for the plunger to make each particular round trip to the surface. The controller periodically changes the time during which the well is shut in to maximize production from the well. Similarly, in U.S. Pat. No. 5,146,991, incorporated herein by reference, the speed at which the plunger arrives at the well head is monitored. Based on the speed detected, changes may be made to the off-cycle time to optimize well production. The forgoing arrangements, while representing an improvement in operating plunger lift wells, still fail to take into account some variables that change during the short term operation of a well. For example, the successful operation of the plunger lift well requires the on-cycle to begin when an ideal pressure differential exists between the casing pressure and the sales line pressure. However, the above optimization schemes operate solely on set time intervals and not directly upon a pressure differential. Therefore, the controller may initiate the on-cycle before the optimal pressure differential has developed. Alternatively, the controller may prematurely end the on-cycle even though production gas flow is still viable. Furthermore, sales lines pressure fluctuations affect the optimal time to commence the on cycle. A fluctuating sales line pressure will cause a change in the effective pressure available to lift liquid out of the well. Simple self-adjusting timed cycle does not take this variable into account when adjusting the length of the cycle. There is a need therefore, for a well control apparatus and method that uses an automated controller to monitor and adjust well components based upon a variety of factors other than time. There is a further need for an automated controller that directly utilizes variables including the sales line pressure and fluctuations thereof. There is a further need for methods and apparatus for automated control of a plunger lift well whereby operating efficiency over time can be measured and adjustments made based upon a variety of factors, including the flow rate of gas from the well over some period of time. SUMMARY OF THE INVENTION The present invention generally relates to an automated method and apparatus for operating an artificial lift well. In one aspect of the present invention, a programmable controller monitors and operates a variety of analog and digital devices. An on-cycle of the well is initiated based on a pressure differential measured between a casing pressure and a sales line pressure. When a predetermined ON pressure differential is observed, the controller initiates the on-cycle and open a motor valve to permit fluid and gas accumulated in the tubing to be urged out of the well. Thereafter, the controller initiates a mandatory flow period and maintains the motor valve open for a period of time. The valve remains open as the system transitions into the sales time period. During sales time, the controller monitors the gas flow through an orifice disposed in the sales line. A differential pressure transducer is used to measure a pressure differential across the orifice. When the measure pressure differential is less than or equal to a predetermined OFF pressure differential, the controller initiates the off cycle. The off cycle starts with a mandatory shut-in period to allow the plunger to fall back into the well. Thereafter, the well remains in the off-cycle until the controller receives a signal that the ON pressure differential has developed. In another aspect of the present invention, the controller may automatically adjust the operating parameters. After a successful cycle, the controller may decrease the predetermined ON pressure differential, increase the mandatory flow period, and/or decrease the predetermined OFF pressure differential to optimize the well's production. Additionally, adjustments may be performed if the well is shut-in before a cycle is completed. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features 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 schematic drawing of a plunger lift system. FIG. 2 is illustrates an exemplary method of the present invention. FIG. 3 is a schematic drawing of a gas lift system. FIG. 4 is illustrates an exemplary hardware configuration of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Plunger Lift System FIG. 1 is a schematic view of aspects of the present invention applied to a plunger lift system 8 . The well 10 includes a wellbore 12 which is lined with casing 14 and a string of production tubing 15 co-axially disposed therein. Perforations 42 are formed in the casing 14 for fluid communication with an adjacent formation 44 . The production tubing 15 and casing 14 extend from a well head 11 located at the surface to the bottom of the well 10 . A plunger 40 is disposed at the bottom of the tubing 15 when the system 8 is shut-in. A lubricator 46 for receiving the plunger 40 is disposed at the top of the tubing 15 . The lubricator 46 includes a plunger arrival sensor 51 for detecting the presence of a plunger 40 and a tubing pressure transducer 53 to monitor the pressure in the tubing 15 . The casing pressure, which is the pressure in an annular area 32 defined by the exterior of the tubing 15 and the interior of the casing 14 , is monitored by a casing pressure transducer 55 disposed adjacent the well head 11 . A first delivery line 26 having a motor valve 28 connects an upper end of the tubing 15 to a separator 24 . The separator 24 separates liquid and gas from the tubing string 15 . Liquid exits the separator 24 through a line 32 leading to a tank (not shown), and gas exits the separator 24 through a sales line 34 . A second delivery line 20 having a well head valve 22 connects the upper end of the tubing 15 to the first delivery line 26 at a position between the motor valve 28 and the separator 24 . The pressure in the sales line 34 is monitored by a sales line pressure transducer 57 . A pressure differential transducer 60 and a plate 68 having an orifice 62 therein are disposed on the sales line 34 to monitor the gas flow across the orifice 62 . Specifically, pressure sensors 64 , 66 are placed before and after the orifice 62 , and their signals are transmitted to the pressure differential transducer 60 , where a pressure differential across the orifice 62 is calculated. A controller 70 receives the measured pressure differential as inputs from the pressure differential transducer 60 and responds to the inputs according to the aspects of the present invention. In operation, the plunger lift system 8 is in the off-cycle with the plunger 40 disposed at the bottom of the well 10 and the motor valve 28 closed. During this time, also known as the “off-time,” the casing pressure increases as a result of an inflow of gases and fluids from the formation 44 to the wellbore 12 through perforations 42 in the casing 14 . The well 10 remains in off-time until a pre-selected “ON” pressure differential exists between the casing pressure and the sales line pressure. Preferably, the pre-selected ON pressure differential is sufficient to raise the plunger 40 along with the accumulated fluids to the surface. Using signals from the casing pressure transducer 55 and the sales pressure transducer 57 , the controller 70 calculates the pressure differential between the casing pressure and the sales pressure. When the ON pressure differential is reached, the controller 70 initiates the on-cycle, or “on time.” In the on time mode, the controller 70 opens the motor valve 28 to expose and reduce the tubing pressure to the sales line pressure. Reducing the tubing pressure unlocks the pressure differential between the sales line pressure and the casing pressure. The pressure differential urges the plunger 40 upward in the tubing 15 and transports a column of fluid thereabove to the well head 11 . Following an on time period, the controller 70 looks for an indication, also known as a “closed contact switch,” to initiate a differential time delay to allow for a mandatory flow period as will be more fully described herein. In one embodiment, the closed contact switch sought by the controller 70 may be a drop in the casing pressure to indicate that the plunger has been lifted. Alternatively, the controller may seek a signal from the plunger arrival sensor 51 to indicate that the plunger 40 has successfully arrived at the surface within a first time period. If the plunger 40 is detected during this first time period, the controller 70 will initiate the mandatory flow period. If the plunger 40 is not detected within this first time period, the controller 70 will continue to look for the closed contact switch within a second time period. During the second time period, the controller 70 may make adjustments to the wellbore 12 conditions to facilitate the plunger's 40 upward progress in the tubing 15 . For example, the controller 70 may be programmed to open a vent valve (not shown) to reduce the tubing pressure in order to decrease the resistance against the plunger's 40 upward movement. Because the movement of the plunger 40 is related to the pressure differential, it may be possible that the plunger 40 fails to reach the surface within the first time period because the wellhead pressure is too high. Therefore, when the controller 70 does not receive an indication that the plunger 40 successfully reached the surface within the first time period, the controller 70 will open the vent valve to facilitate the plunger's 40 ascent. If the plunger 40 is detected during this second time period, the controller 70 will initiate the mandatory flow period and close the vent valve. However, if the plunger 40 fails to reach the surface during this second time period, the controller 70 will shut-in the well 10 and re-enter the off time mode. The mandatory flow period, or differential time delay period, provides a safeguard against loading up the well 10 . As described above, loading up occurs when too much fluid has accumulated above the plunger 40 and the maximum natural pressure differential is not able to move the plunger 40 and the fluid collected up the tubing 15 . During the mandatory flow period, the controller 70 is programmed to ignore a reading from the pressure differential transducer 60 at the sales line 34 that would normally trigger the controller 70 to shut-in the well 10 . As a result, the motor valve 28 remains open to ensure that some of the fluids are removed from the tubing 15 before the plunger 40 falls back to the bottom and collects more fluid. At the expiration of the mandatory flow period, the controller 70 initiates a sales time period. Sales time period is the phase in the cycle when production gas is allowed to flow from the well 10 to the sales line 34 . The gas flow through the sales line 34 is monitored to determine the end of the on-cycle. Specifically, the gas flow is measured by the pressure differential transducer 60 as the gas travels through the plate 68 in the sales line 34 . The measured pressure differential is indicative of the gas flow in the sales line and, therefore, the well production rate. A predetermined “OFF” pressure differential is preprogrammed into the controller 70 as the threshold production rate at which the well 10 will remain in the on-cycle. At the start of the on-cycle, a sufficient amount of gas passes through the pressure differential transducer 60 and results in a large pressure differential. When the measured pressure differential is above the OFF pressure differential, the well 10 is producing above the threshold production rate, and the controller 70 permits the motor valve 28 to remain open. As the well starts to load with liquid, the gas flow across the pressure differential transducer 60 decreases and the measured pressure differential also decreases. When the measured pressure differential is below the OFF pressure differential, the controller 70 will close the motor valve 28 and shut-in the well 10 . After the well 10 is shut-in, the controller 70 initiates a mandatory shut-in period, also known as the plunger fall time. The mandatory shut-in period provides a period of time for the plunger 40 to fall back down the tubing 15 and collect more fluid before the on-cycle is initiated. During the mandatory shut-in period, the controller 70 is programmed to not recognize an ON pressure differential reading and maintain the well 10 in the shut-in mode as the plunger 40 falls back. Once the mandatory shut-in period expires, the controller 70 will begin looking for the ON pressure differential and start a subsequent cycle. If the system 8 successfully completes a cycle, the controller 70 will automatically adjust the parameters of the system 8 to optimize the production. Generally, the controller 70 will adjust the parameters so that the plunger 40 will stay at the bottom for a shorter period of time and the sales line 34 will remain open for a longer period of time. In one embodiment, the controller 70 will decrease the predetermined ON pressure differential for the subsequent cycle by about 10%. As a result, less time is required for the well 10 to develop the reduced ON pressure differential and trigger the on-time mode. Additionally, the differential time delay may be increased by about 10%. The adjustment to the differential time delay will allow the controller 70 to ignore any shut-in readings and keep the motor valve 28 open for a longer period of time. Furthermore, the predetermined OFF pressure differential may be lowered by about 10%. The reduction will allow the production to flow longer before the controller 70 shuts-in the well 10 . Adjustments may also be made if the well 10 does not successfully complete the cycle before shutting-in. As described above, the controller 70 will shut-in the well 10 if the differential time delay is not initiated before the expiration of the prescribed time periods for detecting the plunger 40 arrival. If this occurs, the controller 70 will automatically adjust the parameters of the cycle to ensure that the plunger 40 will reach the surface during the subsequent cycle. In one embodiment, the controller 70 will increase the predetermined ON pressure differential by about 10% in order to provide more force to raise the plunger 40 up the tubing. Also, the differential time delay may be decreased by about 10% and the predetermined OFF differential pressure may be increased by about 10%. In general, these adjustments will increase the probability that the plunger 40 will reach the surface in the subsequent cycle. Furthermore, the controller 70 may adjust the parameters if the OFF pressure differential is met at the expiration of the differential time delay. This situation is not desirable because the controller 70 bypasses the sales time period and shuts-in the well 10 immediately after the differential time delay period. To avoid this situation, the controller 70 decreases the differential time delay and increases the predetermined OFF pressure differential by about 10% each. These adjustments will allow for some sales time period and make the well 10 more productive. According to the aspects of the present invention, the on cycle and the off cycle may be initiated by a single measured point or from the differential between two measured points that are relevant in optimizing the well performance. In the plunger case described above, the on-cycle is initiated based on a pressure differential between the casing pressure and the sales line pressure. However, the controller 70 may be programmed to initiate the on-cycle based on a pressure differential between the casing pressure and the tubing pressure or a pressure differential between the tubing pressure and the sales line pressure. Also, the controller 70 may be programmed to initiate the on-cycle when the casing pressure reaches a specified pressure value. The aspects of the present invention are advantageous in that the production cycle is controlled by the parameters that affect the production of the well 10 . Specifically, the well 10 enters the on time mode only when a beneficial casing pressure and sales line pressure differential is reached. In this respect, the plunger 40 is accorded a higher probability that it will reach the lubricator and deliver the fluid and gases. Thereafter, the well 10 continues to produce sales flow until the production gas flow drops below a predetermined threshold rate. In this respect, the sales flow period is not cut short by a predetermined time period as taught in the prior art. An exemplary method of the present invention may be summarized as shown in FIG. 2 . Using the plunger lift system described above, the system is in the off time mode, shown as step 2 - 5 . W en the ON pressure differential is reached, the controller initiates the ON time mode as shown in step 2 - 1 . During the on time mode, the controller looks for a closed contact switch such as sensing the plunger at the surface. When the closed contact switch is detected, the controller initiates the differential time delay, shown as step 2 - 2 , to allow for removal of fluid from the tubing. At the expiration of the differential time delay, the controller initiates the sales time for production gas flow, shown as step 2 - 3 . Th sales time ends when the OFF pressure differential is met. At the beginning of the off-cycle, the controller initiates the plunger fall time to give the plunger sufficient time to all back down the wellbore as show in step 2 - 4 . At the end of plunger fall time, the system enters the off time mode as shown in step 2 - 5 . During off time mode, the controller makes adjustments to the operating parameters to optimize the well. If the ON pressure differential is adjusted, the cycle will start over when the new ON pressure differential is met. Gas Lift System The aspects of the present invention are also applicable to optimizing a gas lift system 108 . As shown in FIG. 3, the gas lift well 110 includes a wellbore 112 which is lined with casing 114 and a string of production tubing 115 co-axially disposed therein. The production tubing 115 extends from the bottom to the surface of the well 110 , where a shut-in valve 120 is located to close the tubing 115 and shut-in the well 110 . A delivery line 135 is disposed at the other end of the shut-in valve 120 and includes a compressor 130 and a sales valve 137 to close the delivery line 135 . A gas line 140 having a bypass valve 145 is disposed between the compressor 130 and the sales valve 137 to inject compressed gas into the wellbore 112 . A pressure differential transducer 150 and a plate 152 having an orifice 154 therein is disposed between the shut-in valve 120 and the compressor 130 . Pressure sensors 156 , 158 are placed in front of and behind the orifice 154 to measure the gas flow, or pressure differential, across the orifice 154 . The pressure differential transducer 150 sends the measured pressure differential to a controller 160 for processing and executing in accordance with the aspects of the present invention. In operation, the gas lift system 108 is in the on-cycle with the shut-in valve 120 and the sales valve 137 opened and the bypass valve 145 closed to gas flow. The pressure differential transducer 150 receives the readings from the sensors 156 , 158 and calculates the pressure differential across the orifice 154 . The controller 150 compares the measured pressure differential to a predetermined “OFF” pressure differential. When the measured pressure differential drops to or below the OFF pressure differential, indicating that the production gas flow rate is slow, the controller 160 will initiate the off-cycle by closing the sales valve 137 and opening the bypass valve 145 . Compressed gas leaving the compressor 130 enters the bypass line 140 and is delivered back to the wellbore 112 thereby causing the casing pressure to increase. As the casing pressure increases, the gas flow across the orifice 154 will also increase. It must be noted that although the term “off-cycle” is used, the well 110 is not shut-in because the production is recycled through the compressor 130 and back to the well 110 . When a predetermined “ON” pressure differential is detected across the orifice 154 , the controller 160 initiates the on-cycle by closing the bypass valve 145 and opening the sales valve 137 . Generally, the ON pressure differential selected is higher than the OFF pressure differential to allow for a period of production gas flow. The on-cycle begins with a period of mandatory flow time, or differential time delay, during which the pressure differential transducer reading is not recognized by the controller 160 . At the expiration of the mandatory flow period, the controller 160 initiates the sales time period. During this time, the controller 160 will look for the measured pressure differential to drop to or below the OFF pressure differential and start the cycle over. If the system 108 successfully completes a cycle, the controller 160 will automatically adjust the parameters of the system 108 to optimize the production. Generally, the controller 160 will adjust the parameters to achieve more sales time. For example, after a successful cycle, the predetermined ON pressure differential may be decreased by about 10%. As a result, less time is required for the system 108 to develop the reduced ON pressure differential and begin the on-cycle. Alternatively, the differential time delay may be increased by about 10% to guarantee more sales flow. In addition, the predetermined OFF pressure differential may be lowered by about 10%. This adjustment will allow the production gas flow for a longer period of time before the controller 160 initiates the off-cycle. The controller 160 may also make adjustments to the parameters if the OFF pressure differential is met at the expiration of the differential time delay. This situation is not desirable because the controller 160 immediately initiates the off-cycle at the expiration of the differential time delay and sales time is truncated. To avoid this situation, the controller 160 decreases the differential time delay by about 10% so that the controller 160 may initiate the sales time sooner. The Controller The aspects of the present invention can be executed in response to instructions of a computer program executed by a microprocessor or computer controller. For example, a computer program product that runs on a conventional computer system comprising a central processing unit (“CPU”) interconnected to a memory system with peripheral control components. The operating instructions for executing the optimization method of the present invention may be stored on a computer readable medium, and later retrieved and executed by a processing device. The computer program code may be written in any conventional computer readable programming language such as for example C, C++, or Pascal. If the entered code text is in a high level language, the code is compiled, and the resultant compiler code is then linked with an object code of precompiled windows library routines. To execute the linked compiled object code, the system user invokes the object code, causing the computer system to load the code in memory, from which the CPU reads and executes the code to perform the tasks identified in the program. An exemplary hardware configuration for implementing the present invention is illustrated in FIG. 4 . Input device 420 may be used to receive and/or accept input representing basic physical characteristics of an artificial lift system and a well. These basic characteristics may be casing pressure, tubing pressure, sales line pressure, etc. This information is transmitted to a processing device, which is shown as computer 422 in the exemplary hardware configuration. Computer 422 processes the input information according to the programmed code to determine the operational parameters of the artificial lift system. Upon completing the data processing, computer 422 outputs the resulting information to output device 424 . The output device may be configured to operate as a controller for the artificial lift system, which could then alter an operational parameter of the artificial lift system in response to analysis of the system. For example, if analysis of the artificial lift system determines that a full cycle was completed successfully, then the controller may be configured to adjust an operational parameter for a subsequent cycle in order to optimize well production. Alternatively, the output device may operate to display the processing results to the user. Common output devices used with computers that may be suitable for use with the present invention include monitors, digital displays, and printing devices. While the foregoing is directed to embodiments 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.
A programmable controller for operating an artificial lift well is provided to monitor and operate a variety of analog and digital devices. An on-cycle of the well is initiated based on a pressure differential measured between a casing pressure and a sales line pressure. When a predetermined ON pressure differential is observed, the controller initiates the on-cycle and open a motor valve to permit fluid and gas accumulated in the tubing to eurged out of the well. Thereafter, the controller initiates a mandatory flow period and maintains the motor valve open for a period of time. The valve remains open as the system transitions into the sales time period. During sales time, the controller monitors the gas flow through an orifice disposed in the sales line. A differential pressure transducer is used to measure a pressure differential across the orifice. When the measure pressure differential is less than or equal to a predetermined OFF pressure differential, the controller initiates the off cycle. The off cycle starts with a mandatory shut-in period to a low the plunger to fall back into the well. Thereafter, the well remains in the off-cycle until the controller receives a signal that the ON pressure differential has developed. In another aspect, the controller may adjust the operating parameters of the well based on the completion of the cycle.
4
BACKGROUND OF THE INVENTION This invention relates to a mobile node, a mobile agent and a network system. More particularly, this invention relates to a control method which assists the movement of a node between an IP (Internet Protocol) network capable of executing communication in accordance with both IP version 4 and an IP version 6 and an IP network capable of executing communication in accordance with only the IP version 4 or an IP network capable of executing communication in accordance with only the IP version 6, a mobile agent, and a network system for assisting the movement of the node. With a drastic development of small and lightweight nodes and the Internet, the demand for taking out a node from an office or a home to utilize it everywhere has been increased. When the node is moved to other network in the conventional network environment making use of the TCP/IP (Transmission Control Protocol/Internet Protocol), however, setting of the IP address, which is the information for primarily identifying the node in the IP network, must be changed so as to match with the foreign or visiting network environment. Even if this change of setting of the IP address is automatically made by utilizing a DHCP (Dynamic Host Configuration Protocol) described in RFC (Request For Comment) 1541 as one of the methods of distributing automatically the IP addresses, there remains the problem that the network connection that has been established already with other nodes by using the IP addresses used in the network before the movement cannot be maintained in succession. Therefore, methods of assisting the movement of the node between the networks have been devised. A typical among them is a protocol of the third layer (network layer) of an OSI (Open Systems Interconnection) reference model and this protocol pertains to the IP version 4 (hereinafter called the “IPv4”) that has gained a wide application in the Internet and the IP version 6 (hereinafter called the “IPv6”) the specification of which has now been stipulated so as to solve the problems of address exhaustion in the IPv4. As to these IPv4 and IPv6, “IP Mobility Support in IPv4”) (hereinafter called “Mobile IPv4”) described in RFC2002 and “Mobility Support in IPv6”) (hereinafter called “Mobile IPv6”) described in IETF (Internet Engineering Task Force) draft (the latest version of which is “draft-ietf-mobile-ip-ipv6-02.txt”) are examples of the known references. Incidentally, the term “IPv4” used in this specification designates an IP address having an address length of 32 bits while the term “IPv6” designates an IP address having an address length greater than 32 bits. By making use of these Mobile IPv4 and Mobile IPv6, a user can execute communication in the same way before the movement of the node even when the node is moved to another network, without the necessity for changing the IP address of the node or cutting off the network connection that has already been established with other node before the movement. Incidentally, the term “node” used in this specification designates all those devices which have an IP address and execute communication by utilizing the IP, such as a PC (Personal Computer), a WS (Work Station), a router, and so forth. Generally, it is assumed that the movement from the IPv4 to the IPv6 is effected gradually and all the networks do not utilize at once the IPv6. In the mean time, therefore, there exist a network (hereinafter called the “IPv4 network”) comprising only those nodes which execute communication by utilizing only the IPv4 (hereinafter called the “IPv4 nodes”), a network (hereinafter called the “IPv6 network”) comprising only those nodes which execute communication by utilizing only the IPv6 (hereinafter called the “IPv6 node”) and a network (hereinafter called the “IPv4/v6 network”) comprising those nodes which execute communication by utilizing both of IPv4 and IPv6 in mixture (hereinafter called the “IPv4/v6 node”), the IPv4 nodes and the Ipv6 nodes. To beginning with, let's consider the case where the IPv4/v6 network is the one that supports both of Mobile IPv4 and Mobile IPv6. In the Mobile IPv4, messages are exchanged between a mobile node moving between the networks and a mobile agent (hereinafter called the “IPv4 mobile agent”) for assisting the movement of the mobile node which executes communication by utilizing the IPv4, in accordance with the Mobile IPv4 procedures. Similarly, in the Mobile IPv6, messages are exchanged between a mobile node moving between the networks and a mobile agent (hereinafter called the “IPv6 mobile agent”) for assisting the movement of the mobile node that executes communication by utilizing the IPv6, in accordance with the Mobile IPv6 procedures. Let's consider the case where the IPv4/v6 mobile node supporting both of Mobile IPv4 and Mobile IPv6 inside the IPv4/v6 network moves to another IPv4/v6 network. Because the foreign IPv4/v6 network can execute communication by utilizing both of IPv4 and IPv6, the IPv4/v6 mobile node can exchange the messages with both of the IPv4 mobile agent and the IPv6 mobile agent on the network in accordance with the procedures of the Mobile IPv4 and the Mobile IPv6. Therefore, the movement of this IPv4/v6 mobile node between the networks is supported by both of the Mobile IPv4 and the Mobile IPv6. In consequence, the IPv4/v6 mobile node that has moved to the foreign network can successively execute communication without changing setting of the IP address and without cutting off the network connection that has been established already with other IPv4 node or the IPv6 node before its movement by utilizing the IPv4 or IPv6. It can also execute afresh communication with other node by utilizing the IPv4 and the IPv6. Next, let's consider the case where the IPv4/v6 mobile node moves from the IPv4/v6 network to the IPv4 network which can execute communication in accordance with only the IPv4 and supports the Mobile IPv4. In this case, since communication by utilizing the IPv4 is possible between the IPv4/v6 mobile node and the IPv4 mobile agent, the assistance of movement of this mobile node between the networks by the Mobile IPv4 can be made. Therefore, the IPv4/v6 mobile node can execute communication successively after the movement without cutting off the network connection that has been previously established already with other IPv4 node by utilizing the IPv4. The mobile node can also execute communication afresh by utilizing the IPv4. However, the mobile node cannot execute communication by utilizing the IPv6 on the IPv4 network and consequently, the exchange of the message on the IPv4 network in accordance with the Mobile IPv6 procedure becomes impossible between the IPv4/v6 mobile node and the IPv6 mobile agent. In other words, the assistance of the movement of the mobile node to the IPv4 network in accordance with the Mobile IPv6 becomes impossible and the IPv4/v6 mobile node that has moved to the IPv4 network cannot maintain the network that has been established already with other IPv6 node by utilizing the IPv6 before the movement and consequently, cannot execute communication. This mobile node cannot execute afresh communication with other node on the IPv4 network by utilizing the IPv6, either. Similarly, let's consider the case where the IPv4/v6 mobile node moves from the IPv4/v6 network to the IPv6 network which can execute communication by utilizing only the IPv6 and supports the Mobile IPv6. In this case, too, the IPv4/v6 mobile node cannot execute communication by utilizing the IPv4 on the IPv6 network. In consequence, the exchange of the message in accordance with the Mobile IPv4 procedure is not possible on the IPv6 network between the IPv4/v6 mobile agent and the IPv4 mobile agent, so that the assistance of the movement of this mobile node to the IPv6 network in accordance with the Mobile IPv4 becomes impossible on the IPv6 network. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a mobile node, a mobile agent and a network system which can successively maintain the network connection the IPv6 that has been established already by utilizing the IPv6 before the movement when the IPv4/v6 mobile node moves from the IPv4/v6 network to the IPv4 network, and which can also execute afresh communication by utilizing the IPv6. It is another object of the present invention to provide a control method of a mobile node, a mobile agent and a network system for assisting the movement, which can execute communication by utilizing the IPv4 between an IPv4/v6 mobile node and other IPv4 node even when the IPv4/v6 mobile node moves from an IPv4/v6 network to an IPv6 network, without changing at all existing IPv6 mobile agents and existing IPv4/v6 mobile agents and without changing setting of the address of the IPv4/v6 mobile node. According to one aspect of the present invention, there is provided a mobile node including IPv4 (Internet Protocol version 4) processing means for executing services in accordance with the IPv4, IPv6 (Internet Protocol version 6) processing means for executing services in accordance with the IPv6, and communication processing means for executing transmission/reception control of packets to and from networks, and moving between IP networks, wherein the mobile node further comprises movement registration processing means for adding an IPv4 header (IP header used for the IPv4), in which the IPv4 address of a mobile agent is set as a foreign address and the IPv4 address of the mobile node usable in a foreign IPv4 network is set as a home address, to a message used for the IPv6 for registering the movement to a mobile agent connected to the IPv4/v6 network to assist the movement of the mobile node, and transmitting the message, when this mobile node moves from the IPv4/v6 network (a network capable of executing communication by utilizing both of the IPv4 and the IPv6) to an IPv4 network (a network capable of executing communication by utilizing only the IPv4). In the mobile node according to the aspect of the invention described above, the IPv4 header is added to the message used for the IPv6 and the message is then transmitted. Therefore, the message to be used for the IPv6 can be substantially transmitted from the foreign IPv4 network, and the information necessary for the network connection utilizing the IPv6 can be registered to the mobile agent. According to another aspect of the present invention, there is provided a mobile agent including IPv4 processing means for executing services in accordance with an IPv4, IPv6 processing means for executing services in accordance with an IPv6 and communication processing means for executing transmission/reception control of packets to and from networks, and moving between the networks, wherein the mobile agent further comprises packet transmission processing means for generating an IPv4 encapsulated IPv6 packet by adding an IPv4 header, in which the IPv4 address of the mobile agent is set as a foreign address and the IPv4 address of a mobile node usable in a foreign IPv4 network is set as a home address, to an IPv6 packet (packet used for the IPv6) to be transmitted to other node, and transmitting the IPv4 encapsulated IPv6 packet so generated. In the mobile agent according to the aspect of the invention described above, after the IPv4 header is added to the IPv6 packet, the packet is transmitted. Therefore, the IPv6 packet can be transmitted substantially from the foreign IPv4 network. According to still another aspect of the present invention, there is provided a mobile node including IPv4 processing means for executing services in accordance with the IPv4, IPv6 processing means for executing services in accordance with the IPv6 and communication processing means for executing transmission/reception control of packets to and from networks, and moving between the networks, wherein the mobile node further comprises movement detection means for detecting whether the mobile node has moved from the network in which a mobile agent used by this mobile node exists to another IPv4 network or to an IPv6 network (network capable of executing communication by utilizing only the IPv6) or to an IPv4/v6 network, and movement status management means for managing the movement status so detected. Since the mobile node according to this aspect of the invention automatically detects the kind of the network in which the mobile node itself exists at present and manages itself, the necessity for adding an IPv4 header to the message used for the IPv6 or the IPv6 packet can be judged appropriately. According to still another aspect of the present invention, there is provided a mobile agent for assisting the movement of a mobile node executing communication by utilizing an IPv6, including IPv4 processing means for executing services in accordance with an IPv4, IPv6 processing means for executing services in accordance with the IPv6 and communication processing means for executing transmission/reception control of packets to and from networks, wherein the mobile agent further comprises mobile node management means for managing the IPv4 address of a mobile node usable in a foreign IPv4 network when receiving a message for use in the IPv6 for registering the movement, to which an IPv4 header transmitted from the mobile node to the IPv6 network to the mobile agent when the mobile agent moves to the IPv4 network is added, and movement assistance processing means for adding an IPv4 header, in which the IPv4 address of the mobile node usable in a foreign IPv4 network is set as a foreign address and the IPv4 address of the mobile agent is set as a home address, to the message used for the IPv6 to permit registration of the movement to the mobile node, and transmitting the message. In the mobile agent according to the aspect of the invention described above, after the IPv4 header is added to the message used for the IPv6 and then the message is transmitted. Therefore, the message used for the IPv6 can be transmitted substantially to the mobile node that is moving to the IPv4 network. According to still another aspect of the present invention, there is provided a mobile agent for assisting the movement of a mobile node executing communication by utilizing the IPv6, including IPv4 processing means for executing services in accordance with the IPv4, IPv6 processing means for executing services in accordance with the IPv6 and communication processing means for executing transmission/reception control of packets to and from networks, wherein the mobile agent further comprises transfer-to-other node processing means for deleting the IPv4 header when receiving an IPv4 encapsulated IPv6 packet transmitted by the mobile node, and transmitting again the IP packet so taken out to the network. In the mobile agent according to the aspect of the invention described above, after only the IPv6 packet is taken out from the IPv4 encapsulated IPv6 packet, the IPv6 is again transmitted. Therefore, the IPv6 packet can be transmitted substantially from the mobile node, that is moving to the IPv4 network, to the node on the IPv6 network or on the IPv4/v6 network. According to still another aspect of the present invention, there is provided a mobile agent for assisting the movement of a node executing communication by utilizing the IPv6, including IPv4 processing means for executing services in accordance with the IPv4, IPv6 processing means for executing services in accordance with the IPv6 and communication processing means for executing transmission/reception control of packets to and from networks, wherein the mobile agent further comprises transfer-to-other node processing means for generating an IPv4 encapsulated IPv6 packet by adding an IPv4 header, in which the IPv4 address of a foreign node usable in a foreign IPv4 network is set as a foreign IPv4 address and the IPv4 address of the mobile agent is set as a home IPv4 address, to the received IPv6 packet when receiving this IPv6 packet transmitted by other node to the mobile node that has moved to the IPv4 network, and for transmitting this IPv4 encapsulated IPv6 packet. In the mobile agent according to the aspect of the invention described above, after the IPv4 header is added to the IPv6 packet, the IPv6 packet is transmitted. Therefore, the IPv6 packet can be transmitted substantially from the node on the IPv6 network or on the IPv4/v6 network to the mobile node that is moving to the IPv4 network. According to still another aspect of the present invention, there is provided a network system in which an IPv4/v6 network and an IPv4 network are connected with each other by a connecting device or by the connection device and a third network, wherein the mobile agent according to the fourth, fifth or sixth aspect is provided on the IPv4/v6 network and the mobile node according to the first, second or third aspect is provided on the IPv4/v6 network or on the IPv4 network. The network system according to the aspect described above can successively keep the network connection, which utilizes the IPv6 and has been already established before the movement of the IPv4/v6 node, when the IPv4/v6 node moves from the IPv4/v6 network to the IPv4 network, and can execute afresh communication by utilizing the IPv6. According to still another aspect of the present invention, there is provided a method of controlling a mobile node by a mobile agent in a network system in which a first IP network capable of executing communication in accordance with first and second kinds of IPs and a second IP network capable of executing communication in accordance with only the first kind of IP, so that the mobile node capable of executing communication in accordance with the second kind of IP can communicate with other node belonging to the first IP network in accordance with the second kind of IP when the mobile node moves from the first IP network to the second IP network, which method comprises the steps of adding a first kind of IP header, in which the IP address of a second mobile agent belonging to the second IP network in accordance with the first kind of IP is set as a foreign address by the first mobile agent belonging to the first IP network and the IP address of the first mobile agent in accordance with the first kind of IP is set as a home address, to an IP packet transmitted in accordance with the second kind of IP from other node to the mobile node, and transmitting the IP packet to the second mobile agent; and deleting the first kind of IP header by the second mobile agent and transmitting the IP packet to the mobile node. On the other hand, the IP packet may be transmitted to other node by adding the first kind of IP header, in which the IP address of the first mobile agent in accordance with the first kind of IP is set as a foreign address by the second mobile agent and the IP address of the second mobile agent in accordance with the first kind of IP is set as a home address, to the IP packet in accordance with the second kind of IP transmitted from the mobile node to other node, transmitting this IP address to the first mobile agent, deleting the first kind of IP header by the first mobile agent and then transmitting the IP packet to other node. Alternatively, it is possible to employ a method comprising adding the first kind of IP header, in which the IP address of the first mobile agent in accordance with the first kind of IP is set as a foreign address by the second mobile agent and the IP address of the second mobile agent in accordance with the first kind of IP is set as a home address, to a movement registration request message in accordance with the second kind of IP that is received from the mobile node, transmitting this message to the first mobile agent, adding the first kind of IP header, in which the IP address of the second mobile agent in accordance with the first kind of IP is set as a foreign address by the first mobile agent and the IP address of the first mobile agent in accordance with the first kind of IP is set as a home address, to a message in accordance with the second kind of IP for permitting the movement, and transmitting this message to the second mobile agent. The present invention provides also a network system for assisting the movement of the mobile node, having the features described above. Furthermore, the present invention provide the first and second mobile agents for assisting the movement of the mobile node, having the features described above. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view of a network system according to one embodiment of the present invention; FIG. 2 is a structural view of a movement status management table used in an IPv4/v6 mobile node shown in FIG. 1; FIG. 3 is a structural view of a mobile node management table used in an IPv6 mobile agent shown in FIG. 1; FIG. 4 is a flowchart showing an IPv4/v6 movement processing in the IPv4/v6 mobile node shown in FIG. 1; FIG. 5 is a flowchart showing a movement detection processing in the IPv4/v6 shown in FIG. 1; FIG. 6 is a flowchart showing an IPv4 movement registration processing in the IPv4/v6 mobile node shown in FIG. 1; FIG. 7 is a flowchart showing an IPv6 movement registration processing in the IPv4/v6 mobile node shown in FIG. 1; FIG. 8 is a flowchart showing an IPv4-only movement registration processing in the IPv4/v6 mobile node shown in FIG. 1; FIG. 9 is a flowchart showing an IPv6 packet transmission processing in the IPv4/v6 mobile node shown in FIG. 1; FIG. 10 is a flowchart showing an IPv6 movement assistance processing in an IPv6 mobile agent shown in FIG. 1; FIG. 11 is a flowchart showing a transfer-to-mobile node processing in the IPv6 mobile agent shown in FIG. 1; FIG. 12 is a flowchart showing a transfer-to-other node processing in the IPv6 mobile agent shown in FIG. 1; FIG. 13 is a structural view of an IPv6 movement registration request message; FIG. 14 is a structural view of an IPv4 encapsulated IPv6 movement registration request message; FIG. 15 is a structural view of an IPv4 encapsulated IPv6 packet; FIG. 16 is a structural view of an IPv4 encapsulated IPv6 movement registration permission message; FIG. 17 is a structural view of an IPv6 encapsulated IPv6 packet; FIG. 18 is a structural view showing an example of a network to which the present invention is applied; FIG. 19 is an explanatory view showing a structural example of a mobile node management table used in a home IPv6 mobile agent shown in FIG. 18; FIG. 20 is an explanatory view showing a structural example of a mobile agent address table used in a foreign IPv6 mobile agent shown in FIG. 18; FIG. 21 is an explanatory view showing a structural example of a movement assistance management table used in the foreign IPv6 mobile agent shown in FIG. 18; FIG. 22 is an operation flowchart showing an example of the procedure of an IPv4 movement processing in an IPv4/v6 mobile node shown in FIG. 18; FIG. 23 is an operation flowchart showing an example of the procedure of an IPv6 movement processing in the IPv4/v6 mobile node shown in FIG. 18; FIG. 24 is an operation flowchart showing an example of the procedure of an IPv6 movement assistance processing in a home IPv6 mobile agent shown in FIG. 18; FIG. 25 is an operation flowchart showing an example of the procedure of a foreign IPv6 mobile agent shown in FIG. 18; FIG. 26 is an operation flowchart showing an example of the procedure of a transfer-to-foreign IPv6 mobile agent processing in the home IPv6 mobile agent shown in FIG. 18; FIG. 27 is an operation flowchart showing an example of the procedure of a transfer-to-other node processing in the home IPv6 mobile agent shown in FIG. 18; FIG. 28 is an operation flowchart showing an example of the procedure of a transfer-to-home IPv6 mobile agent processing in the foreign IPv6 mobile agent shown in FIG. 18; FIG. 29 is an operation flowchart showing an example of the procedure of a transfer-to-mobile node processing in the foreign IPv6 mobile agent shown in FIG. 18; FIG. 30 is an explanatory view showing a structural example of an IPv6 movement registration request message; FIG. 31 is an explanatory view showing a structural example of a packet obtained by encapsulating an IPv6 encapsulated IPv6 packet by IPv4 encapsulation; FIG. 32 is a structural view showing another example of a network to which the present invention is applied; FIG. 33 is an explanatory view showing a structural example of a mobile node management table used in a home IPv4 mobile agent shown in FIG. 32; FIG. 34 is an explanatory view showing a structural example of a mobile agent address table used in the foreign IPv4 mobile node shown in FIG. 32; FIG. 35 is an explanatory view showing a structural example of a movement assistance management table used in the foreign IPv4 mobile agent shown in FIG. 32; FIG. 36 is an operation flowchart showing an example of the procedure of an IPv4 movement assistance processing in a home IPv4 mobile agent shown in FIG. 32; FIG. 37 is an operation flowchart showing an example of the procedure of the foreign IPv4 movement assistance processing in the foreign IPv4 mobile agent shown in FIG. 32; FIG. 38 is an operation flowchart showing an example of the procedure of a transfer-to-foreign IPv4 mobile agent processing in a home IPv4 mobile agent shown in FIG. 32; FIG. 39 is an operation flowchart showing an example of the procedure of a transfer-to-other node processing in the home IPv4 mobile agent shown in FIG. 32; FIG. 40 is an operation flowchart showing an example of the procedure of a transfer-to-home IPv4 mobile agent in the foreign IPv4 mobile agent shown in FIG. 32; FIG. 41 is an operation flowchart showing an example of the procedure of a transfer-to-mobile node processing in the foreign IPv4 mobile agent shown in FIG. 32; FIG. 42 is an explanatory view showing a structural example of an IPv4 movement registration request message; FIG. 43 is an explanatory view showing a structural example of a packet obtained by IPv6 encapsulation of an IPv4 movement registration permission message; FIG. 44 is an explanatory view showing a structural example of a packet obtained by IPv6 encapsulation of an IPv4 movement registration request message; and FIG. 45 is an explanatory view showing a structural example of a packet obtained by IPv6 encapsulation of an IPv4 packet. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be explained with reference to the accompanying drawings. FIG. 1 is a structural view showing a network system according to one embodiment of the present invention. This network system 1 includes a LAN (Local Area Network)-a 100 which makes use of both an IPv4 and an IPv6, a LAN-b 101 which makes use of only the IPv4 and a WAN (Wide Area Network) 102 which connects the LAN-a 100 and the LAN-b 101 by a public line or an exclusive line. On the LAN-a 100 exist an IPv4 node 103 , an IPv6 node 104 , an IPv4 mobile agent-a 105 for assisting the movement of a node executing communication by utilizing the IPv4 by the procedure in accordance with a Mobile IPv4 between the networks, an IPv4/v6 mobile node 106 and an IPv6 mobile agent 107 for assisting the movement of the node which executes communication by utilizing the IPv4 and IPv6 and also executes communication by utilizing the IPv6 between the networks. The IPv6 mobile agent 107 functions also as a router and connects the LAN-a 100 and the WAN 102 . An IPv4 mobile agent-b 108 and a router 109 exist on the LAN-b 101 . The router 109 connects the LAN-b 101 and the WAN 102 . In this embodiment, the following IP addresses are allocated, respectively: IPv4 address IPv6 address LAN-a 100 “10.0.0.0” “::11.0.0.0” IPv4 node 103 “10.0.0.10” IPv6 node 104 “::11.0.0.30” IPv4/v6 mobile node 106 “10.0.0.1” “::11.0.0.1” IPv4 mobile agent-a 105 “10.0.0.11” IPv6 mobile agent 107 “10.0.0.20” “::11.0.0.20” LAN-b 101 “20.0.0.0” IPv4 mobile agent-b 108 “20.0.0.11” The IPv4/v6 mobile node 106 includes an IPv4/v6 movement processing portion 114 for executing various processings when the node moves to another network, a movement detection processing portion 115 for executing a detection processing which detects the movement to another network, an IPv4 movement registration processing portion 116 for executing a movement notification processing which notifies the movement of the node to another IPv4 network or to an IPv4/v6 network, to the IPv4 mobile agent-a 105 , an IPv6 movement registration processing portion 117 for executing a movement notification processing which notifies the movement of the node to another IPv6 network or to the IPv4/v6 network, to the IPv6 mobile agent 107 , an IPv4-only movement registration processing portion 118 for executing a movement notification processing which notifies the movement of the node to another IPv4 network to the IPv6 mobile agent 107 , a movement status management table 119 for managing the movement status, an IPv4 processing portion 111 for executing a processing in accordance with the services offered by the IPv4, an IPv6 processing portion 112 for executing a processing in accordance with the services offered by the IPv6, an IPv6 packet transmission processing portion 113 for executing a transmission processing of the IPv6 packet, and a communication processing portion 110 for executing a transmission/reception control of the packet to and from the LAN. Among the constituent elements of the IPv4/v6 mobile node 106 described above, the present invention disposes specifically the movement detection processing portion 114 , the IPv4-only movement registration processing portion 118 , the IPv6 packet transmission processing portion 113 and the movement status management table 119 . The IPv6 mobile agent 107 includes an IPv6 movement assistance processing portion 121 which receives the movement report (a report representing the movement to the IPv6 network or to the IPv4/v6 network) from the IPv6 mobile node (not shown in the drawing) effecting communication by utilizing the IPv4/v6 mobile node 106 or IPv6 and moving between the networks, and assists the mobile node, a mobile node management table 126 for managing the movement status information of the mobile nodes, an IPv4 processing portion 122 for executing a processing in accordance with the services offered by the IPv4, a transfer processing portion 123 to another node, for transferring the packet which is transmitted by the IPv4/v6 mobile node 106 to the IPv6 node 104 , an IPv6 processing portion 124 for executing a processing in accordance with the services offered from the IPv6, a transfer processing portion 125 to a mobile node, for transferring the packet which is transmitted from the IPv6 node 104 to the IPv4/v6 mobile node 106 , and a communication processing portion 120 for executing transmission/reception control of the packet to the LAN. Among the constituent elements of the IPv6 mobile agent 107 described above, it is the IPv6 movement assistance processing portion 121 , the transfer processing portion 123 to another node, the transfer processing portion 125 to a mobile node, and a mobile node management table 126 that constitute the characterizing part of the present invention. FIG. 2 shows a structural example of the movement status management table 119 . This movement status management table 119 has the following fields: own IPv4 address 200 : This is the IPv4 address of the IPv4/v6 mobile node 106 on the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. own IPv4 network address 201 : This is the IPv4 network address of the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. own IPv6 address 202 : This is the IPv6 address of the IPv4/v6 mobile node 106 on the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. own IPv6 network address 203 : This is the IPv6 network address of the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. IPv4 mobile agent IPv4 address 204 : This is the IPv4 address of the IPv4 mobile agent-a 105 on the LAN-a 100 on which the IPv4 mobile agent-a 105 for assisting the movement of the IPv4/v6 mobile node 106 exists. IPv6 mobile agent IPv4 address 205 : This is the IPv4 address of the IPv6 mobile agent 107 on the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. IPv6 mobile agent IPv6 address 206 : This is the IPv6 address of the IPv6 mobile agent 107 on the LAN-a 100 on which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists. post-movement IPv4 network address 207 : This is the IPv4 network address of the network on which the IPv4/v6 mobile node 106 exists at the present moment. pre-movement IPv4 network address 208 : This is the IPv4 network address of the network before the IPv4/v6 mobile node 106 moves. post-movement IPv6 network address 209 : This is the IPv6 network address of the network in which the IPv4/v6 mobile node 106 exists at the present moment. When the network existing at present is the IPv4 network, “NULL” is set. pre-movement IPv6 network address 210 : This is the IPv6 network address of the network before the IPv4/v6 mobile node 106 moves. When the network before the movement is the IPv4 network, “NULL” is set. Incidentally, the network address of the LAN-a 100 in which the IPv6 mobile agent 107 for assisting the movement of the IPv4/v6 mobile node 106 exists is set at the time of initialization to the field of each of the post-movement IPv4 network address 207 , the pre-movement IPv4 network address 208 , the post-movement IPv6 network address 209 and the pre-movement IPv6 network address 210 . FIG. 3 shows a structural example of the mobile node management table 126 . This mobile node management table 126 includes the following entries: mobile node IPv6 address 30 : This is the IPv6 address of the mobile node the movement of which is assisted by the IPv6 mobile agent 107 . foreign IPv6 address 31 : This is the IPv6 address on the network on which the mobile node exists at the present moment. When the network existing at present is the IPv4 network, “NULL” is set. foreign IPv4 address 32 : This is the IPv4 address on the network on which the mobile node exists at the present moment. When the network existing at present is the IPv6 network, “NULL” is set. Incidentally, the entry of the mobile node does not exist in the mobile node management table 126 at the time of initialization. FIG. 4 is a flowchart showing the IPv4/v6 movement processing 40 executed by the IPv4/v6 movement processing portion 114 . Initialization of the movement status management table 119 is effected at Step 41 . At the next Step 50 , the movement detection processing portion 115 is caused to repeatedly execute a movement detection processing 50 . FIG. 5 is a flowchart showing the movement detection processing 50 executed by the movement detection processing portion 115 . At Step 51 , the IPv4/v6 mobile node 106 transmits a message transmission request message for detecting the IPv4 movement and a message transmission request message for detecting the IPv6 movement, which request an IPv4 movement detection message and an IPv6 movement detection message for detecting the movement to another IPv4 network, the IPv6 network or the IPv4/v6 network, respectively. The IPv4 mobile agent and the IPv6 mobile agent that receive these message transmission request message for detecting the IPv4 movement and message transmission request message for detecting the IPv6 movement, respectively, transmit the IPv4 movement detection message and the IPv6 movement detection message, respectively. In addition, the IPv4 mobile agent and the IPv6 mobile agent periodically transmit the IPv4 movement detection message and the IPv6 movement detection message, respectively. Next, a timer is set at Step 52 . If the IPv4 movement detection message is received at Step 53 , the flow proceeds to Step 54 and when it is not, the flow proceeds to Step 55 . At Step 54 , the network address of the network, to which the IPv mobile agent transmitting the received IPv4 movement detection message belongs is compared with the post-movement IPv4 network address 207 inside the movement status management table 119 . If they are the same network address, the flow proceeds to Step 55 and if they are different network addresses, the flow proceeds to Step 60 . If the IPv6 movement detection message is received at Step 55 , the flow proceeds to Step 56 and if it is not, the flow proceeds to Step 57 . At Step 56 , the network address of the network to which the IPv6 mobile agent transmitting the IPv6 movement detection message received belongs is compared with the post-movement IPv6 network address 209 inside the movement status management table 119 . If they are the same network address, the flow proceeds to Step 57 and if they are different network addresses, the flow proceeds to Step 70 . At Step 57 , the flow returns to Step 53 if the time is not out, and proceeds to Step 58 if the time is out. At Step 58 , whether or not the post-movement IPv4 network address 207 inside the movement status management table 119 and the pre-movement IPv4 network address 208 are different addresses and whether or not the post-movement IPv6 network address 209 and the pre-movement IPv6 network address are the same network address are judged, and if the result of this judgement proves Yes, the flow proceeds to Step 80 and if the result proves No, the processing is completed. At Step 60 , the IPv4 movement registration processing portion 116 is caused to execute the IPv4 movement registration processing 60 . At Step 70 , the IPv6 movement registration processing portion 117 is caused to execute the IPv6 movement registration processing 70 . At Step 80 , the IPv4-only movement registration processing portion 118 is caused to execute the IPv4-only movement registration processing 80 . The movement detection processing 50 described above will be explained more concretely. When the IPv4/v6 mobile node 106 exists on the LAN-a 100 at the present moment, it receives the IPv4 movement detection message and the IPv6 movement detection message transmitted by the IPv4 mobile agent-a 105 and by the IPv6 mobile agent 107 , respectively. In this instance, since the network address (=“10.0.0.0”) of the LAN-a 100 to which the IPv4 mobile agent-a 105 transmitting the IPv4 movement detection message belongs is the same as the post-movement IPv4 network address 207 (=10.0.0.0”) of the movement status table 119 , it is possible to know that the mobile node does not move to another IPv4 network or another IPv4/v6 network. Therefore, the flow proceeds from Step 54 to Step 55 but Step 60 (IPv4 movement registration processing) is not executed. Since the network address (=“:: 11.0.0.0”) of the network to which the IPv6 mobile agent 107 transmitting the IPv6 movement detection message belongs is the same as the post-movement IPv6 network address 209 (=“::11.0.0.0”) of the movement status table 119 , it is possible to know that the mobile node does not move to another IPv6 or another IPv4/v6 network. Therefore, the flow proceeds from Step 56 to Step 57 but Step 70 (IPv6 movement registration processing) is not executed. Next, when the IPv4/v6 mobile node 106 has moved to the LAN-b 101 at the present moment, this mobile node 106 receives the IPv4 movement detection message transmitted by the IPv4 mobile agent-b 108 . Since the network address (=“20.0.0.0”) of the LAN-b 101 to which the IPv4 mobile agent-b 108 transmitting the IPv4 movement detection message belongs is different from the post-movement IPv4 network address 207 (=“10.0.0.0”) of the movement status table 119 , it is possible to know that the IPv4/v6 mobile node 106 has moved to another IPv4 network or another IPv4/v6 network. Therefore, the flow proceeds from Step 54 to Step 60 , where the IPv4 movement registration processing 60 is executed. As will be described later with reference to FIG. 6, the pre-movement IPv4 network address 208 of the movement status table 119 is updated to “10.0.0.0” and the post-movement IPv4 network address 207 is updated to “20.0.0.0”, by this IPv4 movement registration processing 60 . On the other hand, because the IPv6 mobile agent does not exist in the LAN-b 101 , the IPv6 movement detection message is not received. In consequence, the flow proceeds from Step 55 to Step 57 and the processing of Steps 56 and 70 (IPv6 movement registration processing) is not executed. Because the post-movement IPv4 network address 207 (=“20.0.0.0”) of the movement status table 119 is different from the pre-movement IPv4 network address 208 (=“10.0.0.0”) and because the post-movement IPv6 network address 209 (=“:: 11.0.0.0”) is the same as the pre-movement IPv6 network address 210 (=“:: 11.0.0.0”) after time-out, it is possible to know that the mobile node has moved to the IPv4 network. Therefore, the flow proceeds from Step 58 to Step 80 and the IPv4-only movement registration processing 80 is executed. Incidentally, when the IPv4/v6 mobile node 106 moves to another IPv4/v6 network such as the LAN-a 100 , both of the IPv4 movement detection message and the IPv6 movement detection message are received. Therefore, both of the IPv4 movement registration processing 60 and the IPv6 movement registration processing 70 are executed. On the other hand, the post-movement IPv4 network address 207 of the movement status table 119 becomes inequal (≠) to the pre-movement IPv4 network address 208 and the post-movement IPv6 network address 209 becomes inequal (≠) to the pre-movement IPv6 network address 210 . Therefore, the flow does not proceed from Step 58 to Step 80 and the IPv4-only movement registration processing 80 is not executed. FIG. 6 is a flowchart showing an example of the IPv4 movement registration processing executed by the IPv4 movement registration processing portion 116 . Incidentally, this IPv4 movement registration processing 60 is the processing which follows the processing procedure of the Mobile IPv4. At Step 61 , the IPv4 network address 201 of the movement status management table 119 of its own is compared with the network address of the network to which the IPv4 mobile agent transmitting the IPv4 movement detection message belongs. When they are not the same network address, it is possible to know that the mobile node has moved to another network, and the flow proceeds to Step 62 . When they are the same network address, on the other hand, it is possible to know that the mobile node has returned to the LAN-a 100 in which the IPv6 mobile agent 107 assisting the movement of the IPv4/v6 mobile node 106 exists, and the flow then proceeds to Step 63 . At Step 62 , the IPv4 address on the foreign network which the IPv4/v6 mobile node 106 can make use of is acquired. This IPv4 address can be acquired by utilizing a DHCP for executing automatic distribution of the addresses or by manual setting, for example. At Step 63 , the IPv4 movement registration request message is transmitted to the IPv4 mobile agent registered to the IPv4 mobile node IPv4 address 204 of the movement status management table 119 . At Step 64 , the movement registration permission message as the reply to the IPv4 movement registration request message is awaited from the IPv4 mobile agent, and after this IPv4 movement registration permission message is received, the flow proceeds to Step 65 . At Step 65 , the post-movement IPv4 network address 207 of the movement status management table 119 is substituted for the pre-movement IPv4 network address 208 and then the network address of the network to which the IPv4 mobile agent transmitting the IPv4 movement detection message is substituted for the post-movement IPv4 network address 207 . The IPv4 movement registration processing 60 described above will be explained more concretely. When the IPv4/v6 mobile node 106 moves from the LAN-a 100 to the LAN-b 101 , the flow proceeds from Step 61 to Step 62 and further to Step 63 , and transmits the IPv4 movement registration request message to the IPv4 mobile agent-a 105 . After the IPv4 movement registration permission is received from the IPv4 mobile agent-a 105 , the flow proceeds from Step 64 to Step 65 . Next, “10.0.0.0” is set to the pre-movement IPv4 network address 208 while “20.0.0.0” is set to the post-movement IPv4 network address 207 . FIG. 7 is a flowchart showing an example of the IPv6 movement registration processing executed by the IPv6 movement registration processing portion 117 . Incidentally, this IPv6 movement registration processing 70 is the processing that follows the processing procedure of the Mobile IPv6. At Step 71 , own IPv6 network address 203 of the movement status management table 119 is compared with the network address of the network to which the IPv6 mobile agent transmitting the IPv6 movement detection message belongs. When they are not the same network address, it is possible to know that the mobile node has moved to another network and the flow proceeds to Step 72 . When they are the same network address, on the other hand, it is possible to know that the mobile node has returned to the LAN-a 100 in which the IPv6 mobile agent 107 assisting the movement of the IPv4/v6 mobile node 106 exists, and the flow then proceeds to Step 73 . At Step 72 , the IPv6 address on the foreign network which the IPv4/v6 mobile node 106 can make use of is acquired. Acquisition of this IPv6 address is made by utilizing the DHCP for executing automatic distribution of the addresses or by manual setting, for example. At Step 73 , the IPv6 movement registration request message is transmitted to the IPv6 mobile agent registered to the IPv6 mobile agent IPv6 address 206 of the movement status management table 119 . This IPv6 movement registration request message contains its own IPv6 address 1301 , the foreign IPv6 address 1302 and the foreign IPv4 address 303 as shown in FIG. 13 . This IPv6 movement registration processing 70 sets the IPv6 address held by own IPv6 address 202 of the movement status management table 119 to its own IPv6 address 1301 , the foreign IPv6 address to the foreign IPv6 address 1302 and “NULL” to the foreign IPv4 address 1303 . At Step 74 , the IPv6 movement registration permission message as the reply to the IPv6 movement registration request message is awaited from the IPv6 mobile agent, and after this permission message is received, the flow proceeds to Step 75 . At Step 75 , the post-movement IPv6 network address 209 of the movement status management table 119 is substituted for the pre-movement IPv6 network address 210 and then the network address of the network to which the IPv6 mobile agent transmitting the IPv6 movement detection message belongs is substituted for the post-movement IPv6 network address 209 . FIG. 8 is a flowchart showing an example of the IPv4-only movement registration processing executed by the IPv4-only movement registration processing portion 118 . At Step 81 , the IPv4 encapsulated IPv6 movement registration request message is transmitted to the IPv6 mobile agent registered to the IPv6 mobile agent IPv6 address 206 of the movement status management table 119 . As shown in FIG. 14, this IPv4 encapsulated IPv6 movement registration request message contains an IPv4 header 1401 and an IPv6 movement registration request message 1300 . The IPv4 header 1401 contains in turn a foreign IPv4 address 1402 and a source IPv4 address 1403 . The address of the IPv6 mobile agent IPv4 address 205 of the movement status management table 119 is set to the foreign IPv4 address 1402 and the IPv4 address acquired in the foreign IPv4 network is set to the source IPv4 address 1403 . The IPv6 movement registration request message 1300 shown in FIG. 14 contains its own IPv6 address 1301 , the foreign IPv6 address 1302 and the foreign IPv4 address 1303 as shown in FIG. 13 . The IPv4-only movement registration processing 80 sets the IPv6 address held by the IPv6 address 202 of the movement status management table 119 to its own IPv6 address 1301 , “NULL” to the foreign IPv6 address 1302 and the IPv4 address at the destination to the foreign IPv4 address 1303 . At Step 82 , the IPv4 encapsulated IPv6 movement registration permission request message as the reply to the IPv4 encapsulated IPv6 movement registration request message is awaited from the IPv6 mobile agent, and after this IPv4 encapsulated IPv6 movement registration permission message is received, and the flow proceeds to Step 83 . Incidentally, the IPv4 processing portion 111 removes the IPv4 header from the IPv4 encapsulated IPv6 movement registration permission message (this procedure will be hereinafter called the “IPv4 decapsulation”) and delivers it to the IPv4-only movement registration processing portion 118 . This IPv4 decapsulation in the IPv4 processing portion 111 is one of the services offered by the existing IPv4. At Step 83 , the post-movement IPv6 network address 209 of the movement status management table 119 is substituted for the pre-movement IPv6 network address 210 and then “NULL” is substituted for the post-movement IPv6 network address 209 . The IPv4-only movement registration processing 80 described above will be explained more concretely. When the IPv4/v6 mobile node 106 has moved from the LAN-a 100 to the LAN-b 101 , the following IPv4 encapsulated IPv6 movement registration request message 1400 is generated at Step 81 . IPv4 header: foreign IPv4 address 1402 : “10.0.0.20” (IPv4 address of IPv6 mobile agent 107 ) home IPv4 address 1403 : “20.0.0.1” (IPv4 address that the IPv4/v6 mobile node 106 uses afresh on the LAN-b 101 ) IPv6 movement registration message 1300 : own IPv6 address 1301 : “::11.0.0.1” foreign IPv6 address 1302 : “NULL” foreign IPv6 address 1303 : “20.0.0.1” The IPv4 encapsulated IPv6 movement registration permission message 1400 is transmitted to the IPv6 mobile agent 107 . Next, after the IPv4 encapsulated IPv6 movement registration permission message is received from the IPv6 mobile agent 107 at Step 82 , “::11.0.0.1” is set to the pre-movement IPv6 network address 210 at Step 83 and “NULL” is set to the post-movement IPv6 network address 209 . FIG. 9 is a flowchart showing an example of the IPv6 packet transmission processing 90 executed by the IPv6 packet transmission processing portion 113 of the IPv6 processing portion 112 in the IPv4/v6 mobile node 106 . At Step 91 , the IPv6 packet transmission request by the network application, etc., is awaited, and the flow proceeds to Step 92 if the transmission request is made. At Step 92 , whether or not the IPv6 network address 209 after the movement of the movement status management table 119 is “NULL” is checked and if it is “NULL”, the flow proceeds to Step 93 and if it is not, the flow proceeds to Step 94 . At Step 93 , since the destination is the IPv4 network, the IPv6 packet is encapsulated by IPv4 encapsulation and is transmitted. In other words, the IPv4 header 1401 is added to the IPv6 packet 1501 as shown in FIG. 15, the IPv6 mobile agent IPv4 address 205 of the movement status management table 119 is set to the foreign IPv4 address 1402 of that IPv4 header 1401 , the IPv4 address acquired by the foreign IPv4 network is set to the home IPv4 address, and the IPv4 encapsulated IPv6 packet 1500 is generated and transmitted. The flow then returns to Step 91 described above. At Step 94 , since the destination is the IPv6 network or the IPv4/v6 network, the IPv6 is transmitted as such. The flow then returns to Step 91 described above. The IPv6 packet transmission processing 90 will be explained more concretely. When the IPv4/v6 mobile node 106 moves from the LAN-a 100 to the LAN-b 101 , for example, the IPv4/v6 mobile node 106 receives the transmission request of the IPv6 packet 1501 by the network application at Step 91 . Then, “10.0.0.20” (IPv4 address of the IPv6 mobile agent 107 ) is set as the foreign IPv4 address to this IPv6 packet 1501 at Step 92 and furthermore, the IPv4 header 1401 to which “20.0.0.1” is set as the home IPv4 address 1403 is added. The IPv6 packet encapsulated by this IPv4 encapsulation is transmitted to the IPv6 mobile agent 107 . FIG. 10 is a flowchart showing an example of the IPv6 movement assistance processing 1000 executed by the IPv6 movement assistance processing portion 121 of the IPv6 mobile agent 107 . At Step 1001 , whether or not the message transmission request message for detecting the IPv6 movement is received from the IPv6 mobile node (not shown in the drawing) or the IPv4/v6 mobile node 106 is checked, and if it is, the flow proceeds to Step 1002 and if it is not, the flow proceeds to Step 1003 . At Step 1002 , the IPv6 movement detection message is transmitted to the node which transmits the IPv6 movement detection message transmission request message described above. At Step 1003 , whether or not the IPv6 movement registration request message 1300 is received is checked, and if it is, the flow proceeds to Step 1004 and if it is not, the flow returns to Step 1001 . At Step 1004 , whether or not the movement registration request can be accepted is checked, and if it cannot be accepted, the flow proceeds to Step 1005 and if it can, the flow proceeds to Step 1006 . At Step 1005 , the IPv6 movement registration rejection message is transmitted to the node that transmits the IPv6 movement registration request message 1300 . The flow then returns to Step 1001 described above. At Step 1006 , own IPv6 address 1301 of the IPv6 movement registration request message 1300 is compared with the foreign IPv6 address 1302 and when they are the same address, the flow proceeds to Step 1007 and when they are different addresses, the flow proceeds to Step 1008 . At Step 1007 , the information of the corresponding mobile node inside the mobile node management table 126 is deleted by judging that this mobile node returns to its own network. The flow then proceeds to Step 1011 . At Step 1008 , the foreign IPv4 address 1303 inside the IPv6 movement registration request message 1300 is checked, and if “NULL” is set, the flow proceeds to Step 1009 and if it is not, the flow proceeds to Step 1010 . At Step 1009 , the information of the mobile node is set to the mobile node management table 126 by judging that this mobile node moves to the IPv6 network or to the IPv4/v6 network. In other words, the value of the foreign IPv6 address 1302 inside the IPv6 movement registration request message 1300 so received is set to the foreign IPv6 address 31 inside the mobile node management table 126 and “NULL” is set to the foreign IPv4 address 32 . The flow then proceeds to Step 1011 . At Step 1010 , the information of the corresponding mobile node is set to the mobile node management table 126 by judging that this mobile node has moved to the IPv4 network. In other words, “NULL” is set to the foreign IPv6 address 31 inside the mobile node management table 126 while the value of the foreign IPv4 address 1303 inside the IPv6 movement registration request message 1300 so received is set to the foreign IPv4 address 32 . The flow then proceeds to Step 1012 . At Step 1011 , the IPv6 movement registration permission message is transmitted to the mobile node, and the flow returns to Step 1001 described above. At Step 1012 , the IPv6 movement registration permission message encapsulated by IPv4 encapsulation is transmitted to the mobile node. In other words, as shown in FIG. 16, the IPv4 header 1401 is added to the IPv6 movement registration permission message 1601 , and the foreign IPv4 address 1303 inside the IPv6 movement registration request message 1300 is set to the foreign IPv4 address 1402 of the IPv4 header 1401 . Further, the IPv4 address of the IPv6 mobile agent 107 is set to the home IPv4 address 1403 and the IPv4 encapsulated IPv6 movement registration permission message is generated and transmitted. The flow then returns to Step 1001 . Incidentally, when the IPv4/v6 mobile node 106 moves to the IPv4 network, the IPv4/v6 mobile node 106 transmits the IPv4 encapsulated IPv6 movement registration request message 1300 to the IPv6 mobile agent 107 as described already. When the IPv6 mobile agent 107 receives this IPv4 encapsulated IPv6 movement registration request message 1300 , IPv4 decapsulation of this message is executed at the IPv4 processing portion 122 and the IPv6 movement registration request message 1300 is taken out and delivered to the IPv6 movement assistance processing portion 121 . Since this processing is one of the services offered by the existing IPv4, any new function need not be added to the IPv4 processing portion 122 . The IPv6 movement assistance processing 1000 described above will be explained more concretely. When the IPv4/v6 mobile node 106 has moved from the LAN-a 100 to the LAN-b 101 , the flow proceeds serially to Steps 1001 , 1002 , 1003 and 1004 , and since the foreign IPv6 address 1302 (=“NULL”) inside the IPv6 movement registration request message 1300 is different from own IPv6 address 1301 (=“::11.0.0.1”) at Step 1005 , the flow proceeds to Step 1008 . At Step 1008 , since the foreign IPv4 address 1303 (=“20.0.0.1”) inside the IPv6 movement registration request message 1300 is not “NULL”, the flow proceeds to Step 1010 . At this Step 1010 , “::11.0.0.1” is registered to the mobile node IPv6 address 30 in the mobile node management table 126 as the information of the IPv4/v6 mobile node 106 , “20.0.0.1” is registered to the foreign IPv4 address 32 , and “NULL” is registered to the foreign IPv6 address 31 . At Step 1012 , the IPv4 header 1401 to which “20.0.0.1” is set as the foreign IPv4 address 1402 and “10.0.0.20” is set as the home IPv4 address 1403 is added to the IPv6 movement registration permission message 1601 and is transmitted to the IPv4/v6 mobile node 106 . FIG. 11 is a flowchart showing an example of the transfer-to-mobile node processing 1100 which is executed by the transfer-to-mobile node processing portion 125 of the IPv6 processing portion 124 in the IPv6 mobile agent 107 . At Step 1101 , reception of the IPv6 packet to the mobile node registered to the mobile node management table 126 among the IPv6 packets transmitted by the IPv6 node 104 and other IPv6 nodes (not shown in the drawing) is awaited, and after this packet is received, the flow proceeds to Step 1102 . At Step 1102 , whether or not the foreign IPv6 address 31 of the corresponding mobile node inside the mobile node management table 126 is “NULL” is checked, and if it is “NULL”, the flow proceeds to Step 1103 and if it is not, the flow proceeds to Step 1104 . At Step 1103 , the mobile node as the destination of the IPv6 packet is judged as moving to the IPv4 network, and the IPv6 packet is encapsulated by IPv4 encapsulation and is transmitted to the IPv4 network to which the mobile node as the destination of this packet is moving. The structure of the IPv4 encapsulated IPv6 packet at this time is shown in FIG. 15 . The foreign IPv4 address 32 of the corresponding mobile node inside the mobile node management table 126 is set to the foreign IPv4 address 1402 and the IPv4 address of the IPv6 mobile agent 107 is set to the home IPv4 address 1403 . The flow then returns to Step 1101 . At Step 1104 , the mobile node as the destination of the IPv6 packet is judged as moving to the IPv6 network or to the IPv4/v6 network, and the IPv6 header is added afresh to the IPv6 packet (this processing will be hereinafter called “IPv6 encapsulation”) and is transmitted to the IPv6 network or to the IPv4/v6 network to which the mobile node is moving. In other words, as shown in FIG. 17, the IPv6 header 1701 is added to the IPv6 packet 1704 , the foreign IPv6 address 31 of the corresponding mobile node inside the mobile node management table 126 is set to the foreign IPv6 address 1702 of its IPv6 header 1701 , the IPv6 address of the IPv6 mobile agent 107 is set to the home IPv6 address 1703 and the IPv6 encapsulated IPv6 packet 1700 is generated and transmitted. The flow then returns to Step 1101 . Incidentally, the processing procedure for encapsulating the IPv6 packet by the IPv6 encapsulation is the procedure that follows the Mobile IPv6. The transfer-to-mobile node processing 1100 described above will be explained more concretely. When the IPv4/v6 mobile node 106 has moved from the LAN-a 100 to the LAN-b 101 , “::11.0.0.1” is set as the information of the IPv4/v6 mobile node 106 to the mobile node IPv6 address 30 inside the mobile node management table 126 by the IPv6 movement assistance processing 1000 described already, “NULL” is set to the foreign IPv6 address 31 and “20.0.0.1” is set to the foreign IPv4 address 32 . Therefore, when the IPv6 mobile agent 107 receives the IPv6 packet addressed to the IPv4/v6 mobile node 106 , it adds the header IPv4 header 1401 , in which “20.0.0.1” is set to the foreign IPv4 address 1402 and “10.0.0.20” is set to the home IPv4 address 1403 , to this IPv6 packet and transfers it to the IPv4/v6 mobile node 106 of the LAN-b 101 . This IPv4 encapsulated IPv6 packet 1500 is received by the IPv4/v6 mobile node 106 , is IPv4-decapsulated by the IPv4 processing portion 111 and is processed as the ordinary IPv6 packet. In this way, even when the IPv4/v6 mobile node moves from the LAN-a 100 as the IPv4/v6 network to the LAN-b 101 as the IPv4 network, this mobile node can receive the IPv6 packet transmitted by the IPv6 node 104 of the LAN-a 100 . FIG. 12 is a flowchart showing an example of the transfer-to-other node processing 1200 executed by the transfer-to-other node processing portion 123 of the IPv4 processing portion 122 in the IPv6 mobile agent 107 . At Step 1201 , the mobile agent awaits the reception of the IPv4 packet addressed to its own (IPv6 mobile agent 107 ) and when this packet is received, the flow proceeds to Step 1202 . At Step 1202 , whether or not the IPv4 packet so received is the IPv6 packet encapsulated by IPv4 encapsulation is checked, and when it is the IPv4 encapsulated IPv6 packet, the flow proceeds to Step 1203 and when it is not, the flow proceeds to Step 1205 . At Step 1203 , whether or not the home node of the IPv4 encapsulated IPv6 packet is the mobile node registered to the mobile node management table 126 is checked, and if it is registered, the flow proceeds to Step 1204 and if it is not, the flow proceeds to Step 1205 . At Step 1204 , the IPv4 encapsulated IPv6 packet is decapsulated by IPv4 decapsulation and is transmitted to the network where the node as the destination exists. The flow then returns to Step 1201 . At Step 1205 , the IPv4 packet so received is discarded. The flow then returns to Step 1201 . The transfer-to-other node processing 1200 described above will be explained more concretely. Let's consider the case where the IPv4/v6 mobile node 106 transmits the IPv6 packet to the IPv6 node 104 . In this instance, the IPv6 packet is subjected to IPv4 encapsulation by the IPv6 packet transmission processing 90 by using the IPv4 header 1401 in which “10.0.0.20” is set as the foreign IPv4 address 1402 (addressed to the IPv6 mobile agent 107 ) and “20.0.0.1” is set as the home IPv4 address 1403 , and the IPv4 encapsulated IPv6 packet is transmitted to the IPv6 mobile agent 107 . Receiving this packet, the IPv6 mobile agent 107 removes the IPv4 header 1401 of the IPv4 encapsulated IPv6 packet at Step 1204 after passing through Steps 1201 , 1202 and 1203 , and transmits the IPv6 packet 1501 to the LAN-a 100 in which the IPv6 node 104 as the address exists. This IPv6 packet is received as the ordinary IPv6 packet by the IPv6 node 104 . As described above, even when the mobile node has moved from the LAN-a 100 as the IPv4/v6 network to the LAN-b 101 as the IPv4 network, the IPv4/v6 mobile node 106 can transmit the IPv6 packet to the IPv6 node 104 of the LAN-a 100 . Incidentally, communication utilizing the IPv4 between the IPv4/v6 mobile node 106 and other nodes can be carried out by the movement assistance of the nodes in the IPv6 by the IPv4 mobile agent- 1 105 and the IPv4 mobile agent-b 108 supporting the Mobile IPv4 as the existing method. When the IPv4/v6 mobile node 106 returns from the LAN-b 101 to the LAN-a 100 , the IPv4/v6 mobile node 106 detects the movement to the IPv6 or to the IPv4/v6 network by the movement detection processing described above. The mobile node is judged as returning to the LAN-a 100 by the IPv6 movement registration processing 70 , and transmits the IPv6 movement registration request message 1300 in which “::11.0.0.1” is set to its own IPv6 address, “::11.0.0.1” which is the same as its own IPv6 address 1301 to the foreign IPv6 address 1302 and “NULL” to the foreign IPv4 address 1303 , to the IPv6 mobile agent 107 . Receiving the IPv6 movement registration request message 1300 , the IPv6 mobile agent 107 judges that the IPv4/v6 mobile node 106 returns to the LAN-a 100 because its own IPv6 address inside the IPv6 movement registration request message 1300 is the same as the foreign IPv6 address 1302 , and omits the information on the IPv4/v6 mobile node 106 inside the mobile node management table 126 . As a result, the IPv4/v6 mobile node 106 can make communication utilizing the ordinary IPv6. Incidentally, the IPv4/v6 mobile node 106 reports its return to the LAN-a 100 to the IPv4 mobile agent-a 105 , too, by the IPv4 movement registration request message in accordance with the Mobile IPv4 processing procedure and for this reason, communication utilizing the ordinary IPv4 can be made, too. The embodiment given above automatically detects the movement between the networks by utilizing the IPv4 movement detection message and the IPv6 movement detection message, but it is also possible to employ the construction in which the user of the mobile node reports by himself to the movement detection processing portion 116 so as to execute the IPv4 movement registration processing 60 , the IPv6 movement registration processing 70 or the IPv4-only movement registration processing 80 . Next, another embodiment of the present invention will be explained with reference to the drawings. First, the explanation will be given on the case where the IPv4/v6 mobile node moves from the IPv4/v6 network to the IPv4 network. A structural example of the network system to which the present invention is applied and a structural example of the mobile agent will be explained with reference to FIG. 18 . As shown in the drawing, the network system according to this embodiment includes a LAN-a 1800 , a LAN-b 1801 and a WAN 1802 that connects the LAN-a 1800 and the LAN-b 1801 by a public line or an exclusive line. On the LAN-a 1800 exist an IPv4 node 1803 which executes communication by utilizing only the IPv4 as a protocol of a network layer as the third layer of an OSI reference model, an IPv6 node 1804 which executes communication by utilizing only the IPv6, an IPv4 mobile agent-a 1805 which assists the movement between the networks for the nodes executing communication by utilizing the IPv4 in accordance with the procedure of the Mobile IPv4, an IPv4/v6 mobile node 1806 which executes communication by utilizing both IPv4 and IPv6 and moves between the networks, and a home IPv6 mobile agent 1807 which assists the movement of a node when the node executing communication by utilizing the IPv6 modes to another network. On the LAN-b 1801 exist an IPv4 mobile agent-b 1808 and a foreign IPv6 mobile agent 1809 which assists the movement of a node when the node executing communication by utilizing the IPv4 and the IPv6 and executing communication by utilizing IPv6 comes to the LAN-b 1801 . Incidentally, the home IPv6 mobile agent 1807 functions also as a router handling both of the IPv4 packet and the IPv6 packet and connects the LAN-a 1800 and the WAN 1802 . The router 1810 handling only the IPv4 packet connects the LAN-b 1801 and the WAN 1802 . Therefore, whereas both of the IPv4 packet and the IPv6 packet can come out from the networks beyond the router from the LAN-a 1800 , only the IPv4 packet can come out from the LAN-b 1801 . Incidentally, transmission/reception itself of the IPv4 packet and the IPv6 packet can be made inside the LAN-a 1800 and the LAN-b 1801 . In this embodiment, the IP addresses are listed below: IPv4 address IPv6 address IPv4 node 1803 “10.0.0.10” IPv6 node 1804 “11::20” IPv4/v6 mobile node 1806 “10.0.0.30” “11::30” IPv4 mobile agent-a 1805 “10.0.0.11” home IPv6 mobile agent 1807 “10.0.0.1” “11::1” IPv4 mobile agent-b 1808 “20.0.0.11” foreign IPv6 mobile agent 1809 “20.0.0.1” “21::1” The IPv4/v6 mobile node 1806 comprises an IPv4 movement processing portion 1813 which executes a processing in accordance with the Mobile IPv4 when the node moves to another IPv4 network or to an IPv4/v6 network, an IPv6 movement processing portion 1815 which executes a processing in accordance with the Mobile IPv6 when the mobile node moves to another IPv6 network or to an IPv4/v6 network, an IPv4 processing portion 1812 which executes a processing in accordance with the services offered by the IPv4, an IPv6 processing portion 1814 which executes a processing in accordance with the services offered by the IPv6 and a communication processing portion 1811 which executes a transmission/reception control, etc. of a packet to the LAN. The home IPv6 mobile agent 1807 comprises an IPv6 movement assistance portion 1817 which assists the movement for the mobile node (not particularly shown in the drawing) executing communication by utilizing the IPv6 and moving between the networks or for an IPv6 mobile node 1806 , a mobile node management table 1822 which manages the information of the mobile node that has moved to another IPv6 network or to the IPv4/v6 network, an IPv6 processing portion 1818 which executes a processing in accordance with the services offered by the IPv4, a transfer-to-other node processing portion 1819 which executes a transfer processing of the IPv6 packet, which is transferred from the foreign IPv6 mobile agent 1809 and is transmitted by the IPv4/v6 mobile node 1806 , to the IPv6 node as the destination, an IPv6 processing portion 1820 which executes a processing in accordance with the services offered by the IPv6, a transfer-to-foreign IPv6 mobile agent processing portion 1821 which executes a transfer processing of the IPv6 packet, which is transmitted from another IPv6 node to the IPv4/v6 mobile node 1806 , to the foreign IPv6 mobile agent 1809 and a communication processing portion 1816 which executes a transmission/reception control, etc. of the packet to the LAN. The foreign IPv6 mobile agent 1809 comprises a foreign IPv6 movement assistance portion 1823 which assists the movement of the IPv4/v6 mobile node 1806 when this node 1806 moves to the network (LAN-b 1801 ) to which the foreign IPv6 mobile agent 1809 belongs, a movement assistance management table 1828 which manages the information of this mobile node 1806 , a mobile agent address table 1830 which registers the address information of the home IPv6 mobile agent 1807 , an IPv4 processing portion 1824 which executes a processing in accordance with the services offered by the IPv4, a transfer-to-mobile node processing portion 1825 which executes a processing for transferring the packet, which is transferred from the home IPv6 mobile agent 1807 and is addressed to the IPv4/v6 mobile node 1806 , to the IPv4/v6 mobile node 1806 , an IPv6 processing portion 1826 which executes a processing in accordance with the services offered by the IPv6, a transfer-to-home IPv6 mobile agent processing portion 1812 which executes a processing for transferring the IPv6 packet, which is transmitted by the IPv4/v6 mobile node 1810 to another IPv6 node, to the home IPv6 mobile agent 1807 , and a communication processing portion 1829 which executes a transmission/reception control, etc. of the packet to the LAN. Among the constituent elements of the home IPv6 mobile agent 1807 described above, it is the IPv6 movement assistance portion 1817 , the transfer-to-other node processing portion 1819 , the transfer-to-foreign IPv6 mobile agent processing portion 1821 and the mobile node management table 1822 that constitute the characterizing part of the present invention. Among the constituent elements of the foreign IPv6 mobile agent 1809 , it is the foreign IPv6 movement assistance portion 1823 , the transfer-to-mobile node processing portion 1825 , the transfer-to-home IPv6 mobile agent processing portion 1827 , the mobile agent address table 1830 and the mobile agent management table 1828 that constitute the characterizing part of the present invention. FIG. 19 shows an example of the mobile node management table 1822 . As shown in this drawing, the mobile node management table 1822 includes a mobile node IPv6 address 1920 as the IPv6 address of the mobile node, the foreign IPv6 address 1921 representing the IPv6 address which the mobile node makes use of in the foreign IPv6 network or in the foreign IPv4/v6 network, and a foreign IPv6 mobile agent IPv4 address 1922 representing the IPv4 address of the foreign IPv6 mobile agent 109 . Here, when the mobile node moves to the IPv6 network or to the IPv4/v6 network, “NULL” is set to the foreign IPv6 mobile agent IPv4 address 1922 and when the mobile node moves to the IPv4 network, the IPv4 address of the foreign IPv6 mobile agent 1809 existing inside that network is set to the address 1922 . Incidentally, though the drawing shows the case where the entries for a plurality of mobile nodes exist, the entry of the mobile node does not exist in this table under the initial state. Further, the updating processing of this table will be described later. FIG. 20 shows an example of the mobile agent address table 1830 described above. As shown in this drawing, the mobile agent address table 1830 includes the home IPv6 mobile agent IPv4 address 2030 and the home IPv6 mobile agent IPv6 address 2031 as the IPv4 address and the IPv6 address of all the home IPv6 mobile agents existing in the network system (though this embodiment represents only the home IPv6 mobile agent 1807 on LAN-a 1800 ). This table is set by a manager, for example. FIG. 21 shows an example of the movement assistance management table 1828 described above. As shown in the drawing, the movement assistance management table 1828 includes a mobile node IPv6 address 2140 as the IPv6 address of the IPv4/v6 mobile node 1806 , a home IPv6 mobile agent IPv4 address 2141 as the IPv4 address of the home IPv6 mobile agent 1807 existing in the home network of the mobile node, and a registration flag 2142 representing whether the entry is “tentative registration” or “real registration”. Incidentally, though this drawing represents the case where the entries for a plurality of mobile nodes exist, the entry of the mobile node does not exist in this table under the initial state. The updating processing of this table will be described later. In the construction described above, the processings of the IPv4/v6 mobile node 1806 , the home IPv6 mobile agent 1807 and the foreign IPv6 mobile agent 1809 when the IPv4/v6 mobile node 1806 moves from the LAN-a 1800 as the IPv4/v6 network to the LAN-b 1801 as the IPv4 network, and handling of each table described above, will be explained next in detail. FIG. 22 is a flowchart showing an example of the processing of the IPv4 movement processing portion 1812 for detecting whether or not the IPv4/v6 mobile node 1806 has moved to another IPv4 network or to the IPv4/v6 network, and for executing various processings when the mobile node has moved. By the way, this IPv4 movement processing portion 1812 executes the processing in accordance with the processing procedure of the Mobile IPv4. The IPv4 movement processing portion 1812 first transmits the message transmission request message for detecting the IPv4 movement as the message for requesting the transmission of the IPv4 movement detection message, which is in turn the message for detecting the movement of the mobile node to another IPv4 network or to the IPv4/v6 network (Step 2251 ). Incidentally, the IPv4 movement detection message is transmitted by the IPv4 mobile agent either periodically or when it receives the transmission request message of the IPv4 movement detection. Next, the IPv4 movement processing portion 1812 judges whether or not the IPv4 movement detection message is received (Step 2252 ). When the IPv4 movement detection message is received (Step 2252 YES), the IPv4 movement processing portion 1812 judges from this message whether or not the mobile node moves to another network (Step 2253 ). Incidentally, the network address information is set inside the IPv4 movement detection message, and the movement is detected by comparing this address information with the IPv4 address of the IPv4/v6 mobile node 1806 of its own. When the movement of the mobile node to another network is found as a result of the judgement described above (Step 2253 YES), the IPv4 movement processing portion 1812 judges next whether or not the network as the visiting network is the home network of the IPv4/v6 mobile node 1806 (the LAN-a 1800 is the home network in this embodiment) (Step 2254 ). The IPv4 movement detection message is utilized at the time of this judgement, too. When it is not the home network as a result of this judgement, (Step 2254 NO), the IPv4 movement processing portion 1812 then acquires the foreign IPv4 address that is used by the IPv4 mobile node-a 1805 when it transfers the IPv4 packet bound to the IPv4/v6 mobile node 1806 to the mobile node that is moving to another network (Step 2255 ). The IPv4/v6 mobile node 1806 acquires this foreign IPv4 address from the addresses offered by the IPv4 mobile agent-b 1808 or by utilizing the DHCP that automatically distributes the addresses, or by manual setting. To report and register the movement to the IPv4 mobile agent-a 1805 , the IPv4 movement processing portion 1812 transmits the IPv4 movement registration message (Step 2256 ). Thereafter, the IPv4 movement processing portion 1812 waits for the IPv4 movement registration permission message as the reply of the IPv4 movement registration request message from the IPv4 mobile agent-a 1805 (Step 2257 ) and after this message is received (Step 2257 YES), the flow returns again to the first step 2251 . The IPv4 movement processing portion 1812 repeats the processing described above. FIG. 23 is a flowchart showing an example of the processing of the IPv6 movement processing portion 1815 for detecting whether or not the IPv4/v6 mobile terminal 1806 has moved to another IPv6 network or to the IPv4/v6 network and for executing various processings when this mobile node has moved. Incidentally, this IPv6 movement processing portion 1815 executes the processing in accordance with the procedure of the Mobile IPv6. The IPv6 movement processing portion 1815 first transmits the message transmission request message for detecting the IPv6 movement, which is the message for requesting the transmission of the IPv6 movement detection message as the message for detecting the movement to another IPv6 network or to the IPv4/v6 network (Step 2361 ). Incidentally, this IPv6 movement detection message is transmitted by the IPv6 mobile agent either periodically or when it receives the message transmission request message for detecting the IPv6 movement. Next, the IPv6 movement processing portion 1815 judges whether or not the IPv6 movement detection message is received (Step 2362 ). When this IPv6 movement detection message is received (Step 2362 YES), the IPv6 movement processing portion 1815 judges from this message whether or not the mobile node has moved to another network (Step 2362 ). Incidentally, the network address information is set into the IPv6 movement detection message, and the movement detection is executed by comparing this address information with its own IPv6 address of the IPv4/v6 mobile terminal 1806 . If the result of judgement represents that the mobile node has moved to another network (Step 2363 YES), the IPv6 movement processing portion 1815 judges next whether or not the visiting network is the home network (the LAN-a 1800 is the home network in this embodiment) (Step 2364 ). The IPv6 movement detection message is utilized for this judgement, too. When the destination of the movement is not the home network as a result of the judgement described above (Step 2364 NO), the IPv6 movement processing portion 1815 then acquires the IPv6 address that can be used in the visiting network. Acquisition of this IPv6 address is made by utilizing the DHCP which automatically distributes the address, by the address automatic generation function as one of the functions offered by the IPv6, or by manual setting. In order to report and register the movement to the home IPv6 mobile agent 1807 , the IPv6 movement processing portion 1815 transmits the IPv6 movement registration request message (Step 2366 ). FIG. 30 shows the data structure of the IPv6 movement registration request message transmitted by the IPv4/v6 mobile node 1806 . As shown in the drawing, the IPv6 movement registration request message 3000 includes a IPv6 header 3001 and a IPv6 data 3004 . The IPv6 header 3001 includes a foreign IPv6 address 3002 and a home IPv6 address. The IPv6 address of the home IPv6 mobile agent 1807 is set to the home IPv6 address 3002 , and the IPv6 address which the IPv4/v6 mobile node 1806 acquires in the visiting network is set to the home IPv6 address 3003 . The IPv6 data 3004 includes the IPv6 address 3005 as the IPv6 address of the node itself transmitting this message and the foreign IPv6 address 3006 as the IPv6 address which the mobile node acquires afresh in the visiting network. When the IPv4/v6 mobile node 1806 returns to the LAN-a 1800 as the home network, the same address as its own IPv6 address 3005 is set to the foreign IPv6 address 3006 . Thereafter, the IPv6 movement processing portion 1815 awaits until the IPv6 movement registration permission message as the reply of the IPv6 movement registration request message 3000 is received from the home IPv6 mobile agent 1807 (Step 2367 ) and after this message is received (Step 2367 YES), the flow returns again to the initial Step 2361 . Thereafter, the IPv6 movement processing portion 1815 repeats the processing described above. FIG. 24 is a flowchart showing an example of the processing of the IPv6 movement assistance processing portion 1817 which executes the assistance processing for the movement of the IPv6 mobile node (not particularly shown in the drawing) or the IPv4/v6 mobile node 1806 between the networks. The IPv6 movement assistance processing portion 1817 first judges whether or not the IPv6 movement detection message transmission message is received (Step 2401 ). When this message is found received as a result of this judgement (Step 2401 YES), the IPv6 movement assistance processing portion 1817 transmits the IPv6 movement detection message (Step 2402 ). The IPv6 movement assistance processing portion 1817 then judges whether or not the IPv6 movement registration request message 3000 is received (Step 2403 ). If the message is found received as a result of judgement (Step 2403 YES), the IPv6 movement assistance processing portion further judges whether or not the request for this movement registration is acceptable (Step 2404 ). If the request is found unacceptable as a result of judgement (Step 2404 NO), the IPv6 movement assistance processing portion 1817 transmits the IPv6 movement registration rejection message as the registration rejection reply message of the IPv6 movement registration request message 3000 to the mobile node. If the request is acceptable (Step 2404 YES), the IPv6 movement assistance processing portion 1817 then compares its own IPv6 address 3005 inside the message with the foreign IPv6 address (Step 2406 ). If they are found the same as a result of this comparison (Step 2406 YES), the IPv6 movement assistance processing portion 1817 judges that the mobile node has returned to the home network, and deletes the corresponding information of the mobile node inside the mobile node management table 1812 (Step 2407 ). Then, the IPv6 movement assistance processing portion 1817 transmits the IPv6 movement registration permission message as the registration permission reply message of the IPv6 movement registration request message 3000 to the mobile node (Step 2411 ). When the Ipv6 address 3005 and the foreign IPv6 address 3006 are found as the different addresses as a result of comparison (Step 2406 NO), the IPv6 movement assistance processing portion 1817 further judges whether or not the IPv6 movement registration request message 300 so received is encapsulated by IPv4 encapsulation and transferred from the foreign IPv6 mobile agent 1809 (Step 2008 ). Incidentally, IPv4 encapsulation of the IPv6 movement registration request message 3000 by the foreign IPv6 mobile agent 1809 is effected by the later-appearing foreign IPv6 movement assistance processing portion 1823 inside the foreign IPv6 mobile agent 1809 . When the home IPv6 mobile agent 1807 receives this IPv4 encapsulated IPv6 movement registration request message 3000 , its own IPv4 processing portion 1818 executes IPv4 decapsulation and delivers the decapsulated message to the IPv6 movement assistance processing portion 1817 . This IPv4 decapsulation by the IPv4 processing portion 1818 is one of the services offered by the existing IPv4. When the message is not judged as being transferred as a result of the judgement as to IPv4 decapsulation and transfer (Step 2408 NO), the IPv6 movement assistance processing portion 1817 judges that the mobile node has moved to another IPv6 network or to the IPv4/v6 network and sets the information of this mobile node to the mobile node management table 1822 . At this time, the value of the foreign IPv6 address 3006 inside the IPv6 movement registration request message 3000 , which is received, is set to the foreign IPv6 address 1921 inside the mobile node management table 1822 and “NULL” is set to the foreign IPv6 mobile agent IPv4 address 1922 (Step 2409 ). The IPv6 movement assistance processing portion 1817 then transmits the IPv6 movement registration permission message to the mobile node (Step 2411 ). When the message is found as being IPv4 encapsulated and transferred as a result of the judgement described above (Step 2408 YES), the IPv6 movement assistance processing portion 1817 judges that the mobile node has moved to the IPv4 network and sets the information of this mobile node to the mobile node management table 1822 . At this time, the value of the foreign IPv6 address 3005 inside the IPv6 movement registration request message 3000 , which is transferred, is set to the foreign IPv6 address 1921 inside the mobile node management table 1822 , and the value of the home IPv4 address inside the IPv4 header, which is added to the IPv6 movement registration request message 3000 transferred, is set to the foreign IPv6 mobile agent IPv6 address 1922 . The IPv6 movement assistance processing portion 1817 then executes IPv4 encapsulation of the IPv6 movement registration permission message as the reply to the mobile node and transfers the message (Step 2412 ). The structure of the IPv6 movement registration permission message which is IPv4 encapsulated at this time is the same as the structure 1600 shown in FIG. 16 . The foreign IPv6 mobile agent IPv4 address 1922 registered to the mobile node management table 1822 is set to the foreign IPv4 address 1402 inside the IPv4 header 1401 , and own IPv4 address of the home IPv6 mobile agent 1807 is set to the home IPv4 address 1403 . The IPv6 movement assistance processing portion 1817 completes the processings as described above and repeats thereafter the processing described above. FIG. 25 is a flowchart showing an example of the processing of the foreign IPv6 movement assistance processing portion 1823 which executes the movement assistance processing for the IPv4/v6 mobile node 1806 between the networks at the foreign IPv6 mobile agent 1809 . The foreign IPv6 movement assistance processing portion 1823 first judges whether or not the message transmission request message for detecting the IPv6 movement is received (Step 2501 ). When this message is found received as a result of the judgement (Step 2501 YES), the foreign IPv6 movement assistance processing portion 1823 transmits the IPv6 movement detection message (Step 2502 ). Next, the foreign IPv6 movement assistance processing portion 1823 judges whether or not the IPv6 movement registration request message 3000 is received (Step 2503 ). If this message is found received as a result of the judgement (Step 2503 YES), the IPv6 movement assistance processing portion 1823 registers tentatively the information of this mobile node to the movement assistance management table 1828 (Step 1804 ). At this time, the value of own IPv6 address 3005 inside the IPv6 movement registration request message 3000 received is set to the mobile node IPv6 address 2140 of the movement assistance management table 1828 , and the value of the home IPv6 mobile agent IPv4 address 2030 corresponding to the foreign IPv6 address 3002 inside the IPv6 movement registration request message 3000 is set to the home IPv6 mobile agent IPv4 address 2141 by looking up the mobile agent address table 1830 . Further, “tentative registration” is set to the registration flag. The foreign IPv6 movement assistance processing portion 1823 executes IPv4 encapsulation of the IPv6 registration request message 3000 so received and transfers the encapsulated message to the home IPv6 mobile agent 1807 (Step 2505 ). The structure of the IPv4 encapsulated IPv6 movement registration request message at this time is the same as the structure 1400 shown in FIG. 14 . The IPv4 address 2141 of the home IPv6 mobile agent 1807 registered to the movement assistance management table 1828 is set to the foreign IPv4 address 1402 in the IPv4 header 1401 , and own IPv4 address of the foreign IPv6 mobile agent 1809 is set to the home IPv4 address 1403 . Incidentally, after movement, the IPv4/v6 mobile node 1806 always transmits once the packet to the foreign IPv6 mobile agent 1809 in accordance with the processing procedure of the Mobile IPv6. Therefore, the foreign IPv6 mobile agent 1809 can receive the IPv6 movement registration request message 3000 address to the home IPv6 mobile agent 1807 . The foreign IPv6 movement assistance processing portion 1823 sets the timer (Step 806 ) and waits for the IPv6 movement registration permission message 1601 as the reply of the IPv6 movement registration request message 3000 for a predetermined time (Steps 2507 and 2510 ). Incidentally, the IPv6 movement registration permission message 1601 is encapsulated by IPv4 encapsulation and is transferred by the home IPv6 mobile agent 1807 as described above. When the IPv6 movement registration permission message 1601 is received within the predetermined time (Step 2507 YES), the foreign IPv6 movement assistance processing portion 1823 updates the registration flag 2142 corresponding to the mobile node, which is previously registered tentatively to the movement assistance management table 1828 , to “real registration” assistance management table 1828 , to “real registration” (Step 2508 ). Further, the home foreign IPv6 movement assistance processing portion 1823 executes IPv4 decapsulation of the IPv6 movement registration permission message 1601 received and transfers this message to the IPv4/v6 mobile node 1806 (Step 2509 ). When the IPv6 movement registration permission message 1601 is not received within the predetermined time (Step 2510 YES), the foreign IPv6 movement assistance processing portion 1823 deletes the information of this mobile node from the movement assistance management table 1828 (Step 2511 ). The foreign IPv6 movement assistance processing portion 1823 completes the processings as described above and thereafter executes them repeatedly. FIG. 26 is a flowchart showing an example of the processing of the transfer-to-foreign IPv6 mobile agent processing portion 1821 which transfers the IPv6 packet, which other IPv6 node transmits to the IPv6 mobile node or to the IPv4/v6 mobile node 1806 , to the foreign IPv6 mobile agent 1809 existing in the network to which the mobile node moves, at the home IPv6 mobile agent 1807 . The transfer-to-foreign IPv6 mobile agent processing portion 1821 first judges whether or not the IPv6 packet, which is registered to the mobile node management table 1822 and is addressed to the mobile node, among the IPv6 packets transmitted by the IPv6 node 1804 or other IPv6 nodes (not shown particularly in the drawing) is received (Step 2601 ). If this packet is found received as a result of the judgement, the transfer-to-IPv6 mobile agent processing portion 1821 executes afresh IPv6 encapsulation of this packet (Step 2602 ). The structure of the IPv6 packet encapsulated by IPv6 encapsulation at this time is the same as the structure 1700 shown in FIG. 17 . The corresponding foreign IPv6 address 1921 inside the movement assistance management table 1822 is set to the foreign IPv6 address 1702 inside the IPv6 header 1701 and the IPv6 address of the home IPv6 mobile agent 1807 of its own is set to the home IPv6 address 1703 . The transfer-to-foreign IPv6 mobile agent processing portion 1821 judges next whether or not the foreign IPv6 mobile agent IPv4 address 1922 of the corresponding mobile node inside the mobile node management table 1822 is “NULL” (Step 2603 ). If the foreign IPv6 mobile agent IPv4 address 1922 is found “NULL” as a result of the judgement (Step 2603 NO), the transfer-to-foreign IPv6 mobile agent processing portion 1821 judges that the mobile node is moving to the IPv6 network or to the IPv4/v6 network and transmits as such the IPv6 encapsulated IPv6 packet 1700 (Step 2605 ). Incidentally, the processing procedures for executing IPv6 encapsulation of the IPv6 packet and transmitting the packet follow the procedures of the ordinary Mobile IPv6. If the foreign IPv6 mobile agent IPv4 address 1922 is judged as being other than “NULL” as a result of the judgement (Step 2603 YES), the transfer-to-foreign IPv6 mobile agent processing portion 1821 judges that this mobile node is moving to the IPv4 network, executes further IPv4 encapsulation of the IPv6 packet which has been IPv6 encapsulated already, and transmits it to the foreign IPv6 mobile agent 1809 (Step 2604 ). FIG. 31 shows the structure of the packet 3100 which is IPv4 encapsulated at this time. As shown in the drawing, this packet has the structure in which the IPv4 header 1401 is added afresh to the IPv6 encapsulated IPv6 packet 1700 shown in FIG. 17 . The value of the corresponding foreign IPv6 mobile agent IPv4 address 1922 inside the mobile node management table 1822 is set to the foreign IPv4 address 1402 inside the IPv4 header 1401 and the value of the IPv4 address of the home IPv6 mobile agent 1807 of its own is set to the home IPv4 address 1403 . The transfer-to-foreign IPv6 mobile agent processing portion 1821 completes the processing and thereafter executes repeatedly the processing described above. FIG. 27 is a flowchart showing an example of the processing executed by the transfer-to-other node processing portion 1819 when the IPv6 packet, which the IPv4/v6 mobile node 1806 transfers to other IPv6 node on the foreign IPv4 network, is IPv4 encapsulated and transferred from the foreign IPv6 mobile agent 1809 , to the foreign IPv6 node, in the home IPv6 mobile agent 1807 . The transfer-to-other node processing portion 1819 first judges whether or not the IPv4 packet addressed to the home IPv6 mobile agent 1807 itself is received (Step 2701 ). If it is found received as a result of judgement (Step 2701 YES), the transfer-to-other node processing portion 1819 then judges whether or not the packet so received is encapsulated by IPv4 encapsulation and transferred by the foreign IPv6 mobile agent 1809 (Step 2702 ). Incidentally, the transfer of the IPv6 packet by the foreign IPv6 mobile agent 1809 is executed by the transfer-to-home IPv6 mobile agent processing portion 1827 inside the foreign IPv6 mobile agent 1809 as will be described later. If it is not found the transferred IPv6 packet as a result of judgement (Step 2702 NO), the transfer-to-other node processing portion 1819 discards this packet (Step 2705 ). If it is the transferred IPv6 packet (Step 2702 YES), the transfer-to-other node processing portion 1819 further judges whether or not the home node of this IPv6 packet is the mobile node registered to the mobile node management table 1822 (Step 2703 ). If it is not found registered as a result of this judgement (Step 2703 NO), the transfer-to-other node processing portion 1819 discards this packet (Step 2705 ). If it is found registered (Step 2703 YES), the transfer-to-other node processing portion 1819 decapsulates this packet by IPv4 decapsulation and transmits it to the foreign IPv6 node (Step 2704 ). The transfer-to-other node processing portion completes the processing and thereafter executes repeatedly the processing described above. FIG. 28 is a flowchart showing an example of the processing executed by the transfer-to-home IPv6 mobile agent processing portion 1827 for transferring the IPv6 packet, which is transmitted by the IPv4/v6 mobile node 1806 to other IPv6 node in the foreign IPv6 mobile agent 1809 , to the home IPv6 mobile agent 107 . The transfer-to-home IPv6 mobile agent processing portion 1827 first judges whether or not the IPv6 packet transmitted from the IPv4/v6 mobile node 106 registered to the movement assistance management table 1828 is received (Step 2801 ). If the corresponding packet is found received as a result of this judgement, the transfer-to-home IPv6 mobile agent processing portion 1827 then judges whether or not the registration flag 2142 of the corresponding mobile node inside the mobile node management table 1828 is “real registration” (Step 2802 ). If it is found the “real registration” as a result of this judgement (Step 2802 YES), the transfer-to-home IPv6 mobile agent processing portion 1827 then encapsulates the IPv6 packet so received by IPv4 encapsulation and transmits it to the home IPv6 mobile agent 1807 (Step 2803 ). The structure of the IPv6 packet which is IPv4 encapsulated at this time is the same as the structure 1500 shown in FIG. 15 . The value of the corresponding home IPv6 mobile agent IPv4 address 2141 inside the movement assistance management table 1828 is set to the foreign IPv4 address 1402 inside the IPv4 header 1401 , while own IPv4 address of the foreign IPv6 mobile agent 1809 itself is set to the foreign IPv4 address 1403 . If the registration flag 2142 is not found the “real registration” as a result of the judgement (Step 2802 NO), the transfer-to-home IPv6 mobile agent processing portion 1827 discards the packet (Step 2804 ). The transfer-to-home IPv6 mobile agent processing portion 1827 completes the processing and thereafter executes repeatedly the processing described above. FIG. 29 is a flowchart showing an example of the processing of the transfer-to-mobile node processing portion 1825 which executes the processing for transferring the packet to IPv4/v6 mobile node 1806 when the IPv6 packet, which is transmitted by other IPv6 mobile node to the IPv4/v6 mobile node 1806 by the home IPv6 mobile agent 1807 in the foreign IPv6 mobile agent 1809 , is encapsulated by IPv6 encapsulation, is further encapsulated by IPv4 encapsulation and is transferred. The transfer-to-mobile node processing portion 1825 first judges whether or not the IPv4 packet addressed to the foreign IPv6 mobile agent 1809 is received (Step 2901 ). If the packet is found received as a result of this judgement (Step 2901 YES), the transfer-to-mobile node processing portion 1825 then judges whether or not the packet so received is the one encapsulated by IPv4 encapsulation and transferred by the home IPv6 mobile agent 1807 (Step 2902 ). Incidentally, the transfer of the IPv6 packet by this home IPv6 mobile agent 1807 is executed by the foreign IPv6 mobile agent processing portion 1821 described above. If the packet is not found as the transferred IPv6 packet as a result of the judgement (Step 2902 NO), the transfer-to-mobile node processing portion 1825 discards this packet (Step 2905 ). If it is found as the transferred packet (Step 2902 YES), the transfer-to-mobile node processing portion 1825 further judges whether or not the foreign node of this IPv6 packet is the mobile node really registered to the movement assistance management table 1828 (Step 2903 ). The IPv6 address of the foreign node is the address of the foreign node contained in the IPv6 packet 1704 . If it not found really registered as a result of the judgement (Step 2903 NO), the transfer-to-mobile node processing portion 1825 discards this packet (Step 2905 ). If it is really registered (Step 2903 YES), the transfer-to-mobile node processing portion 1825 decapsulates this packet by IPv4 decapsulation and then transfers it to the IPv4/v6 mobile node 1806 (Step 2904 ). The transfer-to-mobile node processing portion 1825 completes the processing and thereafter executes repeatedly the processing described above. The flow of the processings from FIGS. 22 to 29 described above will be explained hereby with reference to the network system shown in FIG. 18 . When the IPv4/v6 mobile node 1806 exists on the LAN-a 1800 as the home network, the IPv4/v6 mobile node 1806 receives the IPv4 movement detection messages and the IPv6 movement detection message transmitted by the IPv4 mobile agent-a 1805 and the home IPv6 mobile agent 1807 , respectively. Therefore, it is not judged as moving. When the IPv4/v6 mobile node 1806 has moved to the LAN-b 1801 , the IPv4/v6 mobile agent 1806 receives the messages from the IPv4 mobile agent-b 1808 and the foreign IPv6 mobile agent 1809 , respectively. Therefore, the mobile is judged as having moved to other network. The IPv4/v6 mobile node 1806 transmits the IPv4 movement registration request message and the IPv6 movement registration request message 3000 to the IPv4 mobile agent-a 1805 and to the home IPv6 mobile agent 1807 , respectively, by the IPv4 movement processing portion 1813 and the IPv6 movement processing portion 1815 . To this IPv6 movement registration request message 3000 are set “11::1” (home IPv6 mobile agent 1807 ) as the foreign IPv6 address 3002 , “21::30” (assumed as the IPv6 address used afresh on LAN-b 1801 by the IPv4/v6 mobile node 1806 in this embodiment) as the home IPv6 address 3003 , “11::30” (IPv4/v6 mobile node 1806 ) as its own IPv6 address 3005 , and “21::30” as the foreign IPv6 address 3006 . In this embodiment, the IPv6 packet cannot come out from the LAN-b 1801 beyond the router as described above, but can transmit and receive the IPv6 packet inside the LAN-b 1801 . Therefore, the IPv4/v6 mobile node 1806 can receive the IPv6 movement detection message transmitted by the foreign IPv6 mobile agent 1809 , and can also transmit the IPv6 movement registration request message 3000 to the LAN-b 1801 . The IPv6 movement registration request message 3000 is once received by the foreign IPv6 mobile agent 1809 . The foreign IPv6 mobile agent 1809 adds the IPv4 header 1401 , in which “10.0.0.1” (home IPv6 mobile agent 1807 ) is set as the foreign IPv4 address 1402 and “20.0.0.1” (foreign IPv6 mobile agent 1809 ) is set as the home IPv4 address 1403 , to the message by its foreign IPv6 movement assistance processing portion 1823 , and transfers the message to the home IPv6 mobile agent 1807 . Thereafter, this message is received by the home IPv6 mobile agent 1807 . After receiving this message, the home IPv6 mobile agent 1807 adds the IPv4 header 1401 , in which “20.0.0.1” (foreign IPv6 mobile agent 1809 ) is set as the foreign IPv4 address 1402 and “10.0.0.1” (home IPv6 mobile agent 1807 ) is set as the foreign IPv4 address 1403 , to the IPv6 movement registration permission message 1601 by its IPv6 movement assistance processing portion 1817 , and transmits this message to the home IPv6 mobile agent 1809 . Receiving this message, the foreign IPv6 mobile agent 1809 decapsulates this message by IPv4 decapsulation by the foreign IPv6 movement assistance processing portion 1823 and transmits decapsulated message to the IPv4/v6 mobile node 1806 . In consequence, registration of the movement of the IPv4/v6 mobile node 1806 to the home IPv6 mobile agent 1807 is completed. At this time are set “11::30” to the mobile node IPv6 address 20 , “21::30” to the foreign IPv6 address 1921 , and “20.0.0.1” to the foreign IPv6 mobile agent IPv6 address 2140 of the mobile node management table 1822 , as the information of the IPv4/v6 mobile node 1806 . Similarly, “11::30” is set to the mobile node IPv6 address 2140 and “10.0.0.1”, to the home IPv6 mobile agent IPv4 address 2141 of the movement assistance management table 1828 . When the home IPv6 mobile agent 1807 receives the IPv6 packet transmitted by the IPv6 node 1804 to the IPv4/v6 mobile node 1806 , it adds the IPv6 header 1701 , in which “21::30” is set to the foreign IPv6 address 1702 and “11::1” is set to the home IPv6 address 1703 , to this IPv6 packet by its transfer-to-foreign mobile agent processing portion 1821 , and further adds the IPv4 header 1401 , in which “20.0.0.1” is set to the foreign IPv4 address 1402 and “10.0.0.1” is set to the home IPv4 address 1403 , and transfers the packet to the foreign IPv6 mobile agent 1809 . The packet 3100 is received by the home IPv6 mobile agent 1809 . This mobile agent 1809 decapsulates this packet by IPv4 decapsulation by its transfer-to-mobile node processing portion 1825 and transmits it to the IPv4/v6 mobile node 1806 . The IPv4/v6 mobile node 1806 receives and processes this packet as the IPv6 packet in accordance with the ordinary Mobile IPv6 procedure. When the home IPv6 mobile agent 1809 receives the IPv6 packet transmitted by the IPv4/v6 mobile node 1806 to the IPv6 node 1804 , on the contrary, it adds the IPv4 header 1401 , in which “10.0.0.1” (home IPv6 mobile agent 1807 ) is set to the home IPv4 address 1402 and “20.0.0.1” (foreign IPv6 mobile agent 1809 ) is set to the home IPv4 address 1403 , to this packet by the transfer-to-home IPv6 mobile agent processing portion 1827 and transmits the packet to the home IPv6 mobile agent 1807 . This IPv4 encapsulated packet 1500 is received by the home IPv6 mobile agent 1807 . The home IPv6 mobile agent 1807 decapsulates this packet by IPv4 decapsulation by its transfer-to-other node processing portion 1819 and transmits the packet to the foreign IPv6 node 1804 . The foreign IPv6 node 1804 receives and processes this packet as the ordinary IPv6 packet. In the present invention, even when the IPv4/v6 mobile node 1806 moves from the LAN-a 1800 as the IPv4/v6 network to the LAN-b 1801 as the IPv4 network, the IPv4/v6 mobile node 1806 can receive the IPv6 packet transmitted from the IPv4/v6 mobile node 1804 to the IPv4/v6 mobile node 1806 as described above. On the contrary, the existing IPv6 node 1804 can receive the IPv6 packet transmitted by the IPv4/v6 mobile node 1806 to the IPv6 node 1804 . Further, communication making use of the IPv4 between other nodes and the IPv4/v6 mobile node 1806 can be made by means of the movement assistance by the IPv4 mobile agent-a 1805 supporting the Mobile IPv4 as the existing method and the movement assistance on the IPv4 by the IPv4 mobile agent-b 1808 . Incidentally, when the IPv4/v6 mobile node 1806 returns from the LAN-b 1801 to the LAN-a 1800 , the IPv4/v6 mobile node 1806 detects this return to the home network by the IPv6 movement processing portion 1815 described above. Then, the IPv4/v6 mobile node 1806 transmits the IPv6 movement registration request message 3000 in which “11::30” is set to its own IPv6 address 3005 and “11::30” which is the same as its own IPv6 address 3005 is set to the home IPv6 address 3006 , to the home IPv6 mobile agent 1807 . Receiving this IPv6 movement registration request message 3000 , the home IPv6 mobile agent 1807 judges that the IPv4/v6 mobile node has returned to the LAN-a 1800 as the home network because its own IPv6 address 3005 inside this message is the same as the foreign IPv6 address 3006 , and then deletes the information about this mobile node inside the mobile node management table 1822 . In consequence, the IPv4/v6 mobile node 1806 can execute communication utilizing the ordinary IPv6. Similarly, since the IPv4/v6 mobile node 1806 reports its return to the LAN-a 1800 to the IPv4 mobile agent-a 1805 in accordance with the processing procedure of the Mobile IPv4 by the IPv4 movement registration request message. Communication utilizing the ordinary IPv4 can be made, too. In the embodiment described above, the movement of the mobile node between the networks is detected by utilizing the IPv4 movement detection message and the IPv4 detection message, but it is also possible to employ the system construction in which the user of the mobile node indicates by himself to the IPv4 movement processing portion 1813 and to the IPv6 movement processing portion and reports the movement to the IPv4 mobile agent and to the IPv6 mobile agent. Next, the explanation will be given on the case where the IPv4/v6 mobile node moves from the IPv4/v6 network to the IPv6 network. A structural example of the network system to which the present invention is applied and a structural example of the mobile agent will be described with reference to FIG. 32 . As shown in this drawing, the network system according to this embodiment includes a LAN-c 3200 , a LAN-d 3201 and a WAN 1902 connecting the LAN-c 3200 and the LAN-d 3201 by a public line or an exclusive line. On the LAN-c 3200 exist an IPv4 node 3203 executing communication by utilizing only the IPv4, an IPv6 node 3204 executing communication by utilizing only the IPv6, an IPv4/v6 mobile node 1806 executing communication by utilizing both IPv4 and IPv6 and moving between the networks, a home IPv4 mobile agent-c 3206 executing communication by utilizing both IPv4 and IPv6 and assisting the movement of the node, which executes communication by utilizing the IPv4, between the networks, and an IPv6 mobile agent-c 3207 assisting the movement of the node, which executes communication by utilizing the IPv6 in accordance with the Mobile IPv6 procedure, between the networks. On the LAN-d 3201 exist a foreign IPv4 mobile agent 3208 which executes communication by utilizing the IPv4 and IPv6 and assists the movement of the node executing communication by utilizing the IPv4 when this node moves to the LAN-d 3201 , and an IPv6 mobile agent-d 3209 . Here, the IPv4/v6 mobile node 1806 is the same as the one shown in FIG. 18 . Incidentally, the IPv6 mobile agent-c 3207 functions also as a router handling both of the IPv4 packet and the IPv6 packet and connects the LAN-c 3200 and the WAN 3202 . The IPv6 mobile agent-d 3209 functions also as a router handling only the IPv6 packet and connects the LAN-d 3201 and the WAN 3202 . Therefore, both of the IPv4 packet and the IPv6 packet can go out to the external networks beyond the routers, whereas only the IPv6 packet can go out from the LAN-d 3201 . Incidentally, transmission/reception itself of the IPv4 packet and the IPv6 packet inside the LAN-c 3200 and the LAN-d 3201 is possible. In this embodiment, the IP addresses are tabulated below. IPv4 address IPv6 address IPv4 node 3203 “10.0.0.10” IPv6 node 3204 “11::20” IPv4/v6 mobile node 1806 “10.0.0.30” “11::30” home IPv4 mobile agent 3206 “10.0.0.1” “11::1” home IPv4 mobile agent 3208 “20.0.0.1” “21::1” The home mobile agent 3206 includes an IPv4 movement assistance portion 3216 which executes communication by utilizing the IPv4 and assists the movement of an IPv4 mobile node (not particularly shown in the drawing) moving between the networks or an IPv4/v6 mobile node 1806 , a mobile node management table 3217 which manages the information of the mobile node that has moved to another IPv4 network or to the IPv4/v6 network, an IPv4 processing portion 3218 which executes processing in accordance with the services offered by the IPv4, a transfer-to-foreign IPv4 mobile agent processing portion 3219 which executes a processing for transferring the IPv4 packet, which is transmitted by other IPv4 node to the IPv4/v6 mobile node 1806 , to a foreign IPv4 mobile agent 3208 , an IPv6 processing portion 3220 which executes processing in accordance with the services offered by the IPv6, a transfer-to-other node processing portion 3221 which executes a processing for transferring the IPv4 packet, which is transferred from the foreign IPv4 mobile agent 3208 and is transferred to the IPv4/v6 mobile node 1806 , to the foreign IPv4 node, and a communication processing portion 3215 which executes transmission/reception control, etc. of the packet to and from the LAN. The foreign IPv4 mobile agent 3206 comprises a foreign IPv4 movement assistance processing portion 3223 which assists the movement of the IPv4/v6 mobile node 1806 when this node 1806 moves to the network (LAN-d 3201 ) to which the foreign IPv4 mobile agent 3208 belongs, a movement assistance management table 3229 which manages the information of the mobile node, a mobile agent address table 3228 which registers the address information of the home IPv4 mobile agent 3206 , an IPv4 processing portion 3224 which executes a processing in accordance with the services offered by the IPv4, a transfer-to-mobile agent processing portion 3225 which executes a processing for transferring the IPv4 packet, which is transmitted from the IPv4/v6 mobile node 1806 to other IPv4 node, to the home IPv4 mobile agent 3206 , an IPv6 processing portion 3226 which executes a processing in accordance with the services offered by the IPv6, a transfer-to-mobile node processing portion 3227 which executes a processing for transferring the packet, which is transferred from the home IPv4 mobile agent 3206 to the IPv4/v6 mobile node 1806 , to the IPv4/v6 mobile node 1806 , and a communication processing portion 3222 which executes transmission/reception control, etc. of the packet to the LAN. Here, among the constituent elements of the home IPv4 mobile agent 3206 described above, it is the IPv4 movement assistance processing portion 3216 , the mobile node management table 3217 , the transfer-to-foreign IPv4 mobile agent processing portion 3219 and the transfer-to-other node processing portion 3221 that constitute a characterizing part of the present invention. Among the constituent elements of the foreign IPv4 mobile agent 3208 , the constituent elements according to the present invention are the foreign IPv4 movement assistance portion 3223 , the mobile agent address table 3228 , the movement assistance management table 3229 , the transfer-to-home IPv4 mobile agent processing portion 3225 and the transfer-to-mobile node processing portion 3227 . FIG. 33 shows an example of the mobile node management table 3217 described above. As shown in the drawing, the mobile node management table 3217 includes a mobile node IPv4 address 3300 as the IPv4 address of the mobile node, a foreign IPv4 address 3301 representing the foreign IPv4 address when the home IPv4 mobile agent 3206 transfers the IPv4 packet address to the mobile node when this mobile node is moving to another IPv4 network or to the IPv4/v6 network, and a foreign IPv4 mobile agent IPv6 address 3302 representing the IPv6 address of the foreign IPv4 mobile agent. Here, “NULL” is set to the foreign IPv4 mobile agent IPv6 address 3302 when the mobile node is moving to the IPv4 network or to the IPv4/v6 network, and the IPv6 address of the foreign IPv4 mobile agent 3208 existing inside the IPv6 network is set when the mobile node is moving to this IPv6 network. Incidentally, though this drawing illustrates the case where entries for a plurality of moving nodes exist, the entry of the mobile node does not exist under the initial state. The updating processing of this table will be later described. FIG. 34 shows an example of the mobile agent address table 3228 described above. As shown in this drawing, the mobile agent address table 3228 comprises the IPv6 addresses of all the home IPv4 mobile agents existing in the network system (though only the home IPv4 mobile agent 3206 on the LAN-c 3200 is shown in this embodiment), the home IPv4 mobile agent IPv6 address 3400 as the IPv4 address and the home IPv4 mobile agent IPv4 address 3401 . This table is set by a manager, etc. FIG. 35 shows an example of the movement assistance management table 3229 described above. As shown in this drawing, the movement assistance management table 3229 includes a mobile node IPv4 address 3500 as the IPv4 address of the IPv4/v6 mobile node 1806 , a home IPv4 mobile agent IPv6 address 3501 as the IPv6 address of the home IPv4 mobile agent 3206 existing inside the home network of the mobile node, and a registration flag 3502 representing whether the entry is “tentative registration” or “real registration”. Though this drawing illustrates the case where entries for a plurality of mobile nodes exist, the entry for the mobile node does not exist in this table under the initial state. The updating processing of this table will be described later. In the construction described above, the processing operations of the IPv4/v6 mobile node 1806 , the home IPv4 mobile agent 3206 and the foreign IPv4 mobile agent 3208 , and handling of each table described above, when the IPv4/v6 mobile node 1806 has moved from the LAN-c 3200 as the IPv4/v6 network to the LAN-d 3201 as the IPv6 network, will be explained in detail. FIG. 36 is a flowchart showing an example of the processing of the IPv4 movement assistance processing portion 3216 for executing the assistance processing of the IPv4 mobile node (not particularly shown in the drawing) or the IPv4/v6 mobile node 1806 , between the networks. The IPv4 movement assistance processing portion 3216 first judges whether or not the message transmission request message for detecting the IPv4 movement is received (Step 3601 ). When this message is found received as a result of this judgement (Step 3601 YES), the IPv4 movement assistance processing portion 3216 transmits the IPv4 movement detection message (Step 3602 ). Next, the IPv4 movement assistance processing portion 3216 judges whether or not the IPv4 movement registration request message is received (Step 3603 ). Here, FIG. 42 shows the structure of this IPv4 movement registration request message 4200 . As shown in the drawing, the IPv4 movement registration request message 4200 includes an IPv4 header 1401 and an IPv4 data 4201 . The IPv4 header 1401 includes a foreign IPv4 address 1402 and a home IPv4 address 1403 , and the IPv4 address of the home IPv4 mobile agent 3206 is set to the foreign IPv4 address 1402 while the IPv4 address of the IPv4/v6 mobile node 1806 is set to the home IPv4 address 1403 . The IPv4 data 4201 includes the IPv4 address 4202 as own IPv4 address of the node transmitting this message and the foreign IPv4 address 4203 as the foreign address when the IPv4 packet address to this mobile agent is transferred. The same address as the IPv4 address 4202 is set to the foreign IPv4 address 4203 when the IPv4/v6 mobile node 1806 returns to the LAN-c 3200 as the home network. Incidentally, this message is transmitted by the IPv4 movement processing portion 1813 inside the IPv4/v6 mobile node 1806 explained already with reference to FIG. 22 . When the IPv4 movement registration request message 4200 is found received as a result of judgement (Step 3603 YES), the IPv4 movement assistance processing portion 3216 further judges whether or not this movement registration request is acceptable (Step 3604 ). When it found unacceptable as a result of this judgement (Step 3604 NO), the IPv4 movement assistance processing portion 3216 transmits an IPv4 movement registration rejection message as a rejection reply message to the IPv4 movement registration request message 4200 to the mobile node (Step 3605 ). If it is found acceptable (Step 3604 YES), the IPv4 movement assistance processing 3600 then compares its own address 4202 inside the message with the foreign IPv4 address 4203 (Step 3606 ). If own IPv4 address 4202 and the foreign IPv4 address 4203 are found the same as a result of the judgement described above (Step 3606 YES), the IPv4 movement assistance processing portion 3216 judges that the mobile node has returned to the home network and detects the information of the corresponding mobile node inside the mobile node management table 3217 (Step 3607 ). The IPv4 movement assistance processing portion 3216 transmits the IPv4 movement registration permission message as the permission reply message of registration of the IPv4 movement registration request message 4200 to the mobile node (Step 3611 ). If own IPv4 address 4202 and the foreign IPv4 address 4203 are found different as a result of the judgement (Step 3609 NO), the IPv4 movement assistance processing portion 3216 further judges whether or not the IPv4 movement registration request message 4200 received is the message which is encapsulated by IPv6 encapsulation and transmitted by the foreign IPv4 mobile agent 3208 (Step 3608 ). Incidentally, this IPv6 encapsulation of the IPv4 movement registration request message 4200 by the foreign IPv4 mobile agent 3208 is executed by the foreign IPv4 movement assistance processing portion 3223 inside the later-appearing IPv4 mobile agent 3208 . Receiving this IPv4 movement registration request message 4200 which is IPv6 encapsulated in this way, the home IPv4 mobile agent 3206 decapsulates the message by IPv6 decapsulation by its IPv6 processing portion 3220 and delivers the message to the IPv4 movement assistance processing portion 3216 . IPv6 decapsulation by this IPv6 processing portion is one of the services offered by the existing IPv6. If the result of the judgement represents that the message is not IPv6 encapsulated and is not transferred (Step 3608 NO), the IPv4 movement assistance processing portion 3216 judges that the mobile node has moved to another IPv4 network or to the IPv4/v6 network and sets the information of this mobile node to the mobile node management table 3217 (Step 3609 ). At this time, the value of the foreign IPv4 address 4203 inside the received IPv4 movement registration request message 4200 is set to the foreign IPv4 address 3301 inside the mobile node management table 3217 and “NULL” is set to the foreign IPv4 mobile agent IPv6 address 3302 . Then, the IPv4 movement assistance processing portion 3216 transmits the IPv4 movement registration permission message to the mobile node (Step 3611 ). If the message is found the one that is IPv6 encapsulated and is transferred as a result of the judgement (Step 3608 YES), the IPv4 movement assistance processing portion 3216 judges that the mobile node has moved to the IPv6 network and sets the information of this mobile node to the mobile node management table 3217 (Step 3610 ). At this time, the value of the foreign IPv4 address 4203 inside the transferred IPv4 movement registration request message 3300 is set to the foreign IPv4 address 3301 inside the mobile node management table 3217 , and the value of the home IPv6 address inside the IPv6 added to the transferred IPv4 movement registration request message 4200 is set to the foreign IPv4 mobile agent IPv6 address 3302 . The IPv4 movement assistance processing portion 3216 encapsulates and transmits the IPv4 movement registration permission message as the reply to the mobile node (Step 3612 ). The data structure of the IPv6 encapsulated IPv4 movement registration permission message 4301 at this time is shown in FIG. 43 . As shown in the drawing, this message has the construction in which the IPv6 header 1701 is added to the IPv4 movement registration permission message 4301 . The foreign IPv4 mobile agent IPv6 address 3302 registered to the mobile node management table 3217 is set to the foreign IPv6 address 1702 inside the IPv6 header 1701 and own IPv6 address of the home IPv4 mobile agent 3206 itself is set to the home IPv6 address 3003 . The IPv4 movement assistance processing portion 3216 completes the processing and thereafter repeats the processing described above. FIG. 37 is a flowchart showing an example of the processing of the foreign IPv4 movement assistance processing portion 3223 for executing the movement assistance processing of the IPv4/v6 mobile node 1806 between the networks in the foreign IPv4 mobile agent 3208 . The foreign IPv4 movement assistance processing portion 3223 first judges whether or not the message transmission request message for detecting the IPv4 movement is judged (Step 3701 ). If this message is found received as a result of this judgement (Step 3701 YES), the foreign IPv4 movement assistance processing portion 3223 transmits the IPv4 movement detection message (Step 3702 ). Next, the foreign IPv4 movement assistance processing portion 3223 judges whether or not the IPv4 movement registration request message 4200 is received (Step 3703 ). If this message is found received as a result of the judgement (Step 3703 YES), the foreign IPv4 movement assistance processing portion 3223 tentatively registers the information of this mobile node to the movement assistance management table 3229 (Step 3704 ). At this time, the value of own IPv4 address 4202 inside the received IPv4 movement registration request message 4200 is set to the foreign IPv4 address 3500 inside the mobile node management table 3229 and the value of the home IPv4 mobile agent IPv6 address 3400 , that corresponds to the foreign IPv4 address 1402 inside the IPv4 movement registration request, message 4200 , is set to the home IPv4 mobile agent IPv6 address 3501 by looking up the mobile agent address table 3228 . Further, “tentative registration” is set to the registration flag 3502 . The foreign IPv4 movement assistance processing portion 3223 encapsulates by IPv6 encapsulation the IPv4 movement registration request message 4200 so received, and transfers the message to the home IPv4 mobile agent 3206 (Step 3705 ). The structure of the IPv6 encapsulated IPv4 movement registration request message 4200 at this time is shown in FIG. 44 . As shown in this drawing, the message 4400 has the construction in which the IPv6 header 1701 is added to the IPv4 movement registration permission message 4200 shown in FIG. 42 . The home IPv4 mobile agent IPv6 address 3501 registered to the movement assistance management table 3229 is set to the foreign IPv6 address 1702 inside the IPv6 header 1701 , and own IPv6 address of the foreign IPv4 mobile agent 3208 is set to the home IPv6 address 1703 . Incidentally, the IPv4/v6 mobile node 1806 always transmits after its movement the packet to the foreign IPv4 mobile agent 3208 in accordance with the processing procedure of the Mobile IPv4. Therefore, the foreign IPv4 mobile agent 3208 can receive the IPv4 movement registration request message 4200 . The foreign IPv4 movement assistance processing portion 3223 sets the timer (Step 3706 ) and waits for the IPv4 movement registration permission message 4301 as the reply to the IPv4 movement registration request message 4200 for a predetermined time (Steps 3707 and 3710 ). By the way, this IPv4 movement registration permission message 4301 is encapsulated to the IPv6 encapsulated message and is transmitted by the home IPv4 mobile agent 3206 as described above. If the IPv4 movement registration permission message 4301 is received within the predetermined time (Step 3707 YES), the foreign IPv4 movement assistance processing portion 3223 updates the registration flag 3502 corresponding to the mobile node, which has been tentatively registered to the mobile agent management table 3229 previously, to “real registration” (Step 3708 ). Further, the foreign IPv4 movement assistance processing portion 3223 decapsulates by IPv6 decapsulation the IPv6 header 1701 added to the received IPv4 movement registration permission message 4301 and transfers the message to the IPv4/v6 mobile node 1806 (Step 3709 ). If the IPv4 movement registration permission message 4301 is not received within the predetermined time (Step 3701 YES), the foreign IPv4 movement assistance processing portion 3223 deletes the information of this mobile node from the movement assistance management table 3229 (Step 3711 ). The foreign IPv4 movement assistance processing portion 3223 completes the processing and thereafter repeats the processing described above. FIG. 38 is a flowchart showing an example of the processing of the transfer-to-foreign IPv4 mobile agent processing portion 3219 which executes the processing for transferring the IPv4 packet transmitted by other IPv4 node to the IPv4 mobile node (not particularly shown in the drawing) or to the IPv4/v6 mobile agent 1806 to the foreign IPv4 mobile agent 3208 existing in the foreign network of the mobile node, in the home IPv4 mobile agent 3206 . The transfer-to-foreign IPv4 mobile agent processing portion 3219 first judges whether or not the IPv4 packet addressed to the mobile node registered to the mobile node management table 3217 among the IPv4 packets transmitted by the IPv4 node 1804 and other IPv4 nodes (not particularly shown in the drawing) is received (Step 3801 ). If the corresponding packet is found received as a result of this judgement (Step 3801 YES), the transfer-to-foreign IPv4 mobile agent processing portion 3219 then judges whether or not the foreign IPv4 mobile agent IPv6 address 3302 of the corresponding mobile node inside the mobile node management table 3217 is “NULL” (Step 3802 ). If the foreign IPv4 mobile agent IPv6 address 3302 is found “NULL” as a result of the judgement (Step 3802 NO), the transfer-to-foreign IPv4 mobile agent processing portion 3219 judges that the mobile node is moving to the IPv4 network or to the IPv4/v6 network, and encapsulates the IPv4 packet so received by IPv4 encapsulation and transmits the encapsulated packet (Step 3804 ). Incidentally, the processing procedure for effecting IPv4 encapsulation and transferring the packet follows the ordinary Mobile IPv4. If the foreign IPv4 mobile agent IPv6 address 3302 is found to be other than “NULL” as a result of the judgement (Step 3802 YES), the transfer-to-foreign IPv4 mobile agent processing portion 3219 judges that the mobile node is moving to the IPv6 network, encapsulates the received IPv4 packet by IPv6 encapsulation and transmits the encapsulated packet to the foreign IPv4 mobile agent 3208 (Step 3803 ). The structure of the IPv6 encapsulated IPv4 packet at this time is shown in FIG. 45 . This packet has the construction in which the IPv6 header 1701 is added afresh to the IPv4 packet 4501 . The value of the foreign IPv4 mobile agent IPv6 address 3302 inside the mobile node management table 3217 is set to the foreign IPv6 address 1702 inside the IPv6 header 1701 , and own IPv6 address of the home IPv4 mobile agent 3206 is set to the home IPv6 address 1703 . The transfer-to-foreign IPv4 mobile agent processing portion 3219 completes the processing and thereafter executes repeatedly the processing described above. FIG. 39 is a flowchart showing an example of the processing of the transfer-to-other node processing portion 3221 which executes the processing for transferring the packet to the IPv4 node when the IPv4 packet transmitted by the IPv4/v6 mobile node 1806 to other IPv4 node on the foreign IPv6 network is encapsulated by IPv6 encapsulation and transferred by the foreign IPv4 mobile agent 3208 , in the home IPv4 mobile agent 3206 . The transfer-to-other node processing portion 3221 first judges whether or not the IPv6 packet address to the home IPv4 mobile agent 3208 itself is received (Step 3901 ). If the packet is found received as a result of this judgement (Step 3901 YES), the transfer-to-other node processing portion 3221 then judges whether or not the packet is the IPv4 packet that is encapsulated and transferred by the foreign IPv4 mobile agent 3208 (Step 3902 ). Incidentally, this transfer of the IPv4 packet by the foreign IPv4 mobile agent 3208 is executed by the transfer-to-IPv4 mobile agent processing portion 3225 inside the later-appearing foreign IPv4 mobile agent 3208 . If the packet is not found the transferred IPv4 packet as a result of the judgement (Step 3902 NO), the transfer-to-other node processing portion 3221 discards this packet (Step 3905 ). If it is found the transferred IPv4 packet (Step 3902 YES), the transfer-to-other node processing portion 3221 further judges whether or not the foreign node of this IPv4 packet is the mobile node registered to the mobile node management table 3217 (Step 3903 ). If it is not found registered as a result of the judgement (Step 3903 NO), the transfer-to-other node processing portion 3221 discards this packet (Step 3905 ). If it is found registered (Step 3903 YES), the transfer-to-other node processing portion 3221 decapsulates this packet by IPv6 decapsulation and transmits it to the foreign IPv4 node (Step 3904 ). The transfer-to-other node processing portion 3221 completes the processing and thereafter repeats the processing described above. FIG. 40 is a flowchart showing an example of the processing of the transfer-to-home IPv4 mobile agent processing portion 3225 which executes the processing for transferring the IPv4 packet, which the IPv4/v6 mobile node 1806 transmits to other IPv4 nodes, to the home IPv4 mobile agent 3206 in the foreign IPv4 mobile agent 3208 . The transfer-to-home IPv4 mobile agent processing portion 3225 first judges whether or not the IPv4 packet, which is registered to the movement assistance management table 3229 and is transmitted by the IPv4/v6 mobile agent 1806 , is received (Step 4001 ). If the corresponding packet is found received as a result of this judgement (Step 4001 YES), the transfer-to-home IPv4 mobile agent processing portion 3225 then judges whether or not the registration flag 3502 of the corresponding mobile node inside the mobile node management table 3229 is “real registration” (Step 4002 ). If the registration flag is found the “real registration” as a result of the judgement (Step 4002 YES), the transfer-to-home IPv4 mobile agent processing portion 3225 encapsulates the received IPv4 packet by IPv6 encapsulation and transmits it to the home IPv4 mobile agent 3206 (Step 4003 ). The IPv4 packet subjected to IPv6 encapsulation at this time has the same structure as the structure shown already in FIG. 45 . The value of the corresponding home IPv4 mobile agent IPv6 address 3501 inside the movement assistance management table 3229 is set to the foreign IPv6 address inside the IPv6 header 1701 and the IPv6 address of the foreign IPv4 mobile agent 3208 itself is set to the foreign IPv6 address 1703 . If the registration flag 3502 is not found the “real registration” as a result of the judgement (Step 4002 NO), the transfer-to-home IPv4 mobile agent processing portion 3225 discards this packet (Step 4004 ). The transfer-to-home IPv4 mobile agent processing portion 3225 completes the processing and thereafter repeats the processing described above. FIG. 41 is a flowchart showing an example of the processing of the transfer-to-other mobile node processing portion 3227 which executes the processing for transferring the packet to the IPv4/v6 mobile node 1806 when the IPv4 packet transmitted by other IPv4 node to the IPv4/v6 mobile node 1806 by the home IPv4 mobile agent 3206 is encapsulated by IPv6 encapsulation and is transferred, in the foreign IPv4 mobile agent 3208 . The transfer-to-mobile node processing portion 3227 first judges whether or not the IPv6 packet addressed to the foreign IPv4 mobile agent 3208 itself is received (Step 4101 ). If it is found received as a result of this judgement (Step 4101 YES), the transfer-to-mobile node processing portion 3227 then judges whether or not the received packet is the IPv4 packet which is IPv6 encapsulated and transferred by the home IPv4 mobile agent 3206 (Step 4102 ). Incidentally, this transfer of the IPv4 packet by the home IPv4 mobile agent 3206 is executed by the home IPv4 movement assistance processing portion 3219 described above. If the packet is not the transferred IPv4 packet as a result of the judgement (Step 4102 NO), the transfer-to-mobile node processing portion 3227 discards this packet (Step 4105 ). If it is the transferred IPv4 packet (Step 4102 YES), the transfer-to-mobile node processing portion 3227 further judges whether or not the node of this IPv4 packet is the mobile node registered really to the movement assistance management table 3229 (Step 4103 ). If the node is not found registered really (Step 4103 NO) as a result of this judgement, the transfer-to-mobile node processing portion 3227 discards the packet (Step 4105 ). If it is found registered really (Step 4103 YES), the transfer-to-mobile node processing portion 3227 decapsulates this packet by IPv6 decapsulation and transfers the packet to the IPv4/v6 mobile agent 1806 (Step 4104 ). The transfer-to-other node processing is completed and thereafter the processing described above is repeatedly executed. The flow of the processings shown in FIG. 22 and in FIGS. 36 to 41 will be explained with reference to the network system shown in FIG. 32 . When the IPv4/v6 mobile node 1806 exists on the LAN-c 3200 as the home network, the IPv4/v6 mobile node 1806 is judged as not moving because it receives the IPv4 movement detection message and the IPv6 movement detection message transmitted by the home IPv4 mobile agent 3206 and the IPv6 mobile agent-c 3207 , respectively. When the IPv4/v6 mobile node 1806 has moved to the LAN-d 3201 , the IPv4/v6 mobile node 1806 is judged as having moved to another network because it receives the IPv4 movement detection message and the IPv6 movement detection message transmitted by the foreign IPv4 mobile agent 3208 and the IPv6 mobile agent-d 3209 , respectively. Then, the IPv4/v6 mobile node transmits the IPv4 movement registration request message 4200 and the IPv6 movement registration request message 3000 by means of the IPv4 movement processing portion 1813 and the IPv6 movement processing portion 1815 to the home IPv4 mobile agent 3206 and to the IPv6 mobile agent-c 3207 , respectively. To this IPv4 movement registration request message 4200 are set “10.0.0.1” (home IPv4 mobile agent 3206 ) as the foreign IPv4 address 1402 , “10.0.0.30” as its own IPv4 address 3202 and “20.0.0.30” (as the foreign IPv4 address which the IPv4/v6 mobile node 1806 acquires from the foreign IPv4 mobile agent 3208 in the foreign LAN-d 3201 in this embodiment), as the transfer IPv4 address. In this embodiment, the IPv4 packet cannot come out from the LAN-d 3201 beyond the router to the external network as described above but can transmit/receive the IPv4 packet inside the LAN-d 3201 . Therefore, the IPv4/v6 mobile node 1806 can receive the IPv4 movement detection message transmitted by the foreign IPv4 mobile agent 3208 and can also transmit the IPv4 movement registration request message 4200 to the LAN-d 3201 . This IPv4 movement registration request message 4200 is once received by the foreign IPv4 mobile agent 3208 . The foreign IPv4 mobile agent 3208 adds the IPv6 header 1701 , in which “11::1” (home IPv4 mobile agent 3206 ) is set as the foreign IPv6 address 1702 and “21::1” (foreign IPv4 mobile agent 3208 ) is set as the home IPv6 address 1703 , to this message 4200 by means of its foreign IPv4 movement assistance processing portion 3223 , and transfers the message to the home IPv4 mobile agent 3206 . Thereafter, this message is received by the home IPv4 mobile agent 3206 . After receiving this message, the home IPv4 mobile agent 3206 adds the IPv6 header 1701 , in which “21::1” (foreign IPv4 mobile agent 3206 ) is set as the foreign IPv6 address 1702 ) and “11::1” (home IPv4 mobile agent 3208 ) is set as the home IPv6 address 1703 , to the IPv4 movement registration permission message 4301 by means of its IPv4 movement assistance processing portion 3216 , and transfers the message to the foreign IPv4 mobile agent 3208 . Receiving this message, the foreign IPv4 mobile agent 3208 decapsulates the message by IPv6 decapsulation by its foreign IPv4 movement assistance processing portion 3223 and transmits the message to the IPv4/v6 mobile node 1806 . In this way, registration of the movement of the IPv4/v6 mobile node 1806 to the home IPv4 mobile agent 3206 is completed. At this time, “10.0.0.30” is set as the information of the IPv4/v6 mobile node 1806 to the mobile node IPv4 address 3300 of the mobile node management table 3217 , “20.0.0.30” is set to the foreign IPv4 address 3301 and “21::1” is set to the foreign IPv4 mobile agent IPv6 address 3302 . Further, “10.0.0.30” is set to the mobile node IPv4 address 3500 of the movement assistance management table 3229 and “11::1” is set to the foreign IPv4 mobile agent IPv6 address 3501 . Receiving the IPv4 packet transmitted from the IPv4 node 3203 to the IPv4/v6 mobile node 1806 , the home IPv4 mobile agent 3206 adds the header 1701 , in which “21::1” (foreign IPv4 mobile agent 3208 ) is set to the foreign IPv6 address 1702 and “11::1” (home IPv4 mobile agent 3206 ) is set to the home IPv6 address 1703 , to the IPv4 packet by means of the transfer-to-foreign IPv4 mobile agent processing portion 3219 , and transfers the packet to the foreign IPv4 mobile agent 3208 . The IPv6 encapsulated packet is received by the foreign IPv4 mobile agent 3208 . The foreign IPv4 mobile agent 3208 decapsulates this packet by IPv6 decapsulation by its transfer-to-node processing portion 3227 and transmits it to the IPv4/v6 mobile node 1806 . The IPv4/v6 mobile node 1806 receives and processes this packet as the IPv4 packet in accordance with the procedure of the ordinary Mobile IPv4. When the IPv4/v6 mobile node 106 receives the IPv4 packet transmitted to the IPv4 node 3203 , on the contrary, the foreign IPv4 mobile agent 3208 adds the IPv6 header 1701 , in which “11::1” (home IPv4 mobile agent 3206 ) is set to the foreign IPv6 address 1702 and “21::1” (foreign IPv4 mobile agent 3208 ) is set to the home IPv6 address 1703 , to the packet by means of the transfer-to-home IPv4 mobile agent processing portion 3205 and transmits the packet to the home IPv4 mobile agent 3206 . The IPv6 encapsulated packet is received by the home IPv4 mobile agent 3206 . The home IPv4 mobile agent 3206 decapsulates this packet by IPv6 decapsulation by its transfer-to-other node processing portion 3221 and then transmits it to the foreign IPv4 node 3203 . The IPv4 node 3203 receives and processes this packet as the ordinary IPv4 packet. According to the present invention described above, even when the IPv4/v6 mobile node 1806 moves from the LAN-c 3200 as the IPv4/v6 network to the LAN-d 3201 as the IPv6 network, the IPv4/v6 mobile node 1806 can receive the IPv4 packet transmitted by the IPv4 node 3203 to the IPv4/v6 mobile node 1806 . On the contrary, the existing IPv4 node 3203 can receive the IPv4 packet transmitted by the IPv4/v6 mobile node 1806 to the IPv4 node 3203 . Communication by making use of the IPv6 between other node and the IPv4/v6 mobile node 1806 can be made by the assistance of movement by the IPv6 mobile agent-c 3207 supporting the IPv6 and by the assistance of movement of the node in the IPv6 by the IPv6 mobile agent-d 3209 . Incidentally, when the IPv4/v6 mobile node 1806 returns from the LAN-d 3201 to the LAN-c 3200 , the IPv4/v6 mobile node 1806 detects its return to the home network by the IPv4 movement processing 1813 described already. Then, the IPv4/v6 mobile node 1806 transmits the IPv4 movement registration request message, in which “10.0.0.30” is set to its own address 4202 and “10.0.0.30” having the same address as its own IPv4 address 4202 to the foreign IPv4 address 4203 , to the home IPv4 mobile agent 3206 . Receiving this IPv4 movement registration request message 4200 , the home IPv4 mobile agent 3206 judges that the IPv4/v6 mobile node 1806 has returned to the LAN-c 3200 as the home network because its own IPv4 address 4202 in the message has the same address as that of the foreign IPv4 address 4203 , and then deletes the information of this mobile node in the mobile node management table 3217 . As a result, the IPv4/v6 mobile node 1806 can make communication by utilizing the ordinary IPv4. Similarly, the IPv4/v6 mobile node 1806 reports the return to the LAN-c 3200 by the IPv6 movement registration request message 3000 to the IPv6 mobile agent-c 3207 , too, in accordance with the processing procedure of the Mobile IPv6. Therefore, communication utilizing the ordinary IPv6 can be made, as well.
A mobile node moves from a first IP (Internet Protocol) network to a second IP network in a network system in which the first IP network capable of executing communication in accordance with both first and second kinds of IPs and the second IP network capable of executing communication in accordance with only the first kind of IP are connected with each other. When the mobile node communicates a message with other nodes on the first network after its movement accordance with the second kind of IP, a header for the movement containing both home and foreign addresses of the first kind in IP is added to a header containing home and foreign addresses in the second kind of IP, and put to the message, is added. The message to which the movement header is thus added is used for the communication between a first mobile agent on the first network and a second mobile agent on the second network, or between the mobile node and the first mobile agent.
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CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 08/576,850 filed Dec. 22, 1995, now abandoned which is a continuation of U.S. application Ser. No. 08/118,186 filed Sep. 9, 1993, now abandoned. FIELD OF THE INVENTION The present invention relates to recycling waste paper, and more particularly to recycling processes for making absorbent granular materials from waste paper. BACKGROUND OF THE INVENTION Paper recycling has, in recent years, become a more important and attractive option to disposal of waste paper by deposition in landfills or by incineration. It has been a common practice for many years to make paper, especially tissue, from recycled paper. Typically, the waste paper is supplied to a hydropulper where the paper is pulped with caustic, dispersants and large amounts of water to form a slurry of fibers, fines and fillers. The slurry passes through a de-inking treatment, and possibly other treatments, and then is supplied to a paper making machine where fibers are removed from the slurry to make the paper (paper-making fibers). The reject stream from the pulping process generally includes significant amounts of organic materials such as cellulosic fibers too short to be of use in making recycled paper (short fibers), along with tannin, lignin, etc., and inorganic materials, particularly kaolin clay, calcium carbonate and titanium dioxide, which are suspended in the water used in the recycling process. In view of stringent water quality standards, it is desirable to recycle the water from the recycling process by removing the reject material from the waste stream. It is further desirable to provide a use for the reject materials removed from the waste stream. Various processes have been proposed for recovering paper-making fibers from post-consumer waste paper and magazines for use in making paper. The shorter fibers (generally less than 1.0 mm in length) are not satisfactory for making paper and are removed with the reject stream. Often the reject stream is dewatered and then sent to a landfill or incinerator. However, restrictions on landfills and incinerators make the disposal of the rejects prohibitively expensive. As an alternative, it has been proposed to convert the reject into useful products. Such products include industrial absorbents for oil and water, and animal litter and feed. These products are also used as soil conditioners and agricultural carriers for spreading pesticides, and as fillers for building materials. U.S. Pat. Nos. 3,980,050; 4,203,388; 4,560,527; and 4,621,011, for example, disclose processes for turning a waste material, such as waste paper, newsprint, etc., into useful products including animal litter, oil absorbent, mulch, or a carrier for other materials. The fibers from the waste material are formed into particles and dried. SUMMARY OF THE INVENTION It is an object of the present invention to provide an efficient and economical process for utilizing waste paper materials in producing useful granular products. More particularly, an object of this invention is to beneficially reuse a portion of the waste paper that is not acceptable for papermaking. The process of this invention utilizes waste paper, preferably office waste that is printed with laser print, Xerox print, or other inks, and magazines that have a coated surface. The waste paper is pulped with water, caustic and surfactants to produce a slurry containing paper fibers, paper fines and fillers. After several washing steps, the slurry passes through a wire washer which separates paper-making fibers from the fines and filler. The paper-making fiber stream, also referred to as the "accepts stream", is directed to a conventional papermaking machine for processing into paper. The filtrate from the washer continues through the process of this invention by flowing into a flotation clarifier where the suspended solids (fines and filler) are concentrated as a flotate and clarified water is removed for reuse in the process. In order to sterilize the absorbent material without using biocidal chemicals, the flotate is pasteurized at a minimum temperature of 160° F. This flotate is then passed through a belt press where the water content is further reduced. The filter cake from the belt press is in the form of a gray, wet cake that resembles and has the consistency of modeling clay. The wet cake then passes, by means of a screw conveyor, to an agglomerator where the material is formed into a granular shape. The wet granules are then sent through a conveyor dryer to produce dry granules of irregular shape and having good absorbent characteristics. The granules produced by this process have a high absorbency toward liquids. Their composition, by weight, is approximately 50% inorganic fillers (kaolin clay, calcium carbonate, titanium dioxide) and 50% organic (cellulose fines, starches, tannins, lignin, etc.). Less than 10% of the cellulosic material is in the form of fibers greater than 1 mm in length. The bulk density of the granules is between 28-35 lbs./cu.ft. These granules are useful as oil and water absorbents as well as carriers for agricultural chemicals. DESCRIPTION OF THE DRAWING A preferred embodiment of the invention is illustrated in the accompanying drawing, in which: FIG. 1 is a schematic view of the process and apparatus for performing the process for manufacturing the granules according to the present invention. DETAILED DESCRIPTION The process of this invention utilizes waste paper that is collected from offices or other sources that contain primarily recyclable paper grades, including magazines (with clay-based coatings) and writing grades (with laser print, Xerox print and other inks). Paper-making fibers that can be used to make paper are separated in this process from a reject stream which includes inks, fines (cellulose less than 0.1 mm in length) and fillers (kaolin clay, calcium carbonate, titanium oxide, etc.). Referring to FIG. 1, waste paper is supplied to a hydropulper 2 along with clarified water, caustic agents, such as sodium hydroxide, and dispersants to separate the fiber from the other components of the waste paper. Plastics, debris and other foreign objects are removed by conventional means. The pulp slurry from the hydropulper, which contains more than 95% water, passes through a pipe 4 to a washer 6 where several conventional washing steps are performed. In the washer 6, the slurry flows over wire screens where paper-making fibers are retained on the screens and the reject stream passes through the screen and is conducted out of the washer through a pipe 8. The paper-making fibers that are retained on the screen are subject to further cleaning, de-inking and processing, indicated at 10, before being supplied through a pipe 12 to a papermaking machine 14. More than 95% of the long fibers in the pulp slurry are removed and pass into the pipe 12. The reject stream from the wire screen washer 6 is in the form of a slurry containing less than 1% solids, including cellulosic fines and fillers. Typically 50% of the solids are fillers such as kaolin clay, calcium carbonate and titanium dioxide. The remaining 50% is mostly cellulose fines which are less than 1 mm in length, with some sugars, tannins, lignins, etc. This slurry, which contains between 99% and 99.5% water, is conducted through the pipe 16 to a dissolved air flotation clarifier 18. Suitable clarifiers are commercially available (e.g., Supracell from Krofta, or Deltafloat from Meri). A flocculating polymer, such as Drewfloc 441 from Drew Chemical Co., or Calgon TRP 945, and air are added to the reject stream in the pipe 16 before it enters the clarifier. The slurry fills the clarifier 18, and the flocculated suspended solids float on the air bubbles to the surface of the clarifier. At this point, the mat of solids, which has a consistency of 3-6%, is skimmed or raked off the surface and removed from the clarifier through the pipe 20. The clarified water from the clarifier 18 is conducted back into the hydropulper 2 through the pipe 22. In accordance with this invention, mill process effluent that contains long fibers may be utilized to increase the efficiency of the process. This effluent would include reject water streams, spills from pulp and paper mills, etc. In FIG. 1, the effluent stream would include a process white water stream 23 from the papermaking machine 14, an overflow stream 24 which would previously have been discharged to a sewer, and a white water stream 25. The process white water is returned to the washer 6. The overflow stream 24 is supplied to a fiber recovery process 26 where the stream passes through screens that separate the paper-making fibers in a similar manner to the washer 8. Paper-making fibers with water are supplied through the pipe 28 from the fiber recovery unit 26 to the washer 6. A fiber-free slurry flows through the pipe 30 to a flotation clarifier 32 that operates in the same manner as the clarifier 18. The white water stream 25 from the papermaking machine is supplied to another flotation clarifier 27 where the flocculated suspended solids are removed in the same manner as in the clarifier 18. A stream containing 3-7% solids passes out of the clarifier 32 and the clarifier 27 through the pipe 34. Clarified water from the clarifier 32 flows through the pipe 33 and is available for use in the process. The flotate from the clarifiers 18, 27 and 32 is mixed to form a single concentrated stream and is supplied to a heater 36. The heater 36 may be of any suitable type, such as a steam injection unit, or a heat exchanger. The flow rate of the stream and the heat applied should be sufficient to raise the temperature of the stream for sufficient time to achieve pasteurization of the stream. Preferably, the stream should be heated to a temperature of at least 160° F. The stream passes out of the heat exchanger 36 through a pipe 38, and a second flocculating polymer (such as Drewfloc 453 from Drew Chemical Co.) is added to the slurry to cause the solids to agglomerate before the slurry enters a belt press 40. The belt press can be any one of the commercially-available units (e.g., Kompress Belt Filter Press, Model GRS-S-2.0 from Komline Sanderson). At the outlet of the belt press, the filter cake is 35-40% solids and has the consistency of moist modeling clay. Process white water from the belt press is returned to the hydropulper 2 through the pipe 42. The filter cake from the belt press 40 is conveyed by means of a screw conveyor 44 to a pin-mixer type agglomerator 46. In the agglomerator 46 (such as Dust-Maler Model #020 from Feeco International), the filter cake is broken up by the rotating pins, so that uniform granules are formed as the material progresses from the inlet of the agglomerator to the outlet. It has been found that the agglomerator 46 produces optimum size particles by running in the middle of its speed range, which is at 540 RPM. Higher speeds give larger particles than desired. Lower speeds yield a larger variability in sizes, with no net increase in smaller sized granules. It is important that no additional water be added to the agglomerator, since the slurry passing through should have a consistency of 35-45% in order to yield the desired size and texture of the granules. A higher consistency produces more fines and a lower consistency produces larger and more variable sized granules. The lignin, tannin and starch in the slurry serve as the binder for the granules. From the agglomerator 46, the granulated, but still moist stream material moves, preferably under the force of gravity on a swing conveyor 48, to the belt of a conveyor drier 50, such as a Proctor & Schwartz two-stage conveyor dryer. The conveyor dryer 50 preferably includes a housing through which the granular material moves while supported on the belt. The belt is porous and a heater blows hot air though the belt to dry the granules. At the outlet, the granules have a minimum solids content of 90% by weight, and preferably greater than 95%. Vibrating screens 52, such as manufactured by Sweco, are used to classify the material by size according to product specifications. The granules produced by this process contain approximately 50% by weight of organic materials, such as cellulosic fines, starches, tannins and lignins. This process removes at least 90% of fibers over 1 mm in length, and the granules contain less than 10% paper-making fiber. The inorganic fillers comprise about 50% by weight of the granules and are made up primarily of kaolin clay, calcium carbonate and titanium dioxide. The granules have an irregular, generally spherical shape. The granules from the conveyor dryer vary in size. Typically, 50% will be retained on an 8×16 mesh screen, i.e., 50% would pass through an U.S. Sieve No. 8 mesh screen but would be retained on a 16 mesh screen. Typically, the remaining portion would be 44% in the 16×30 mesh size range, and 6% in the 30×60 mesh size range. The granules have a bulk density of between 28-35 lbs/cu. ft. The granular material according to the present invention is preferably able to withstand agitation such as might occur during shipment, handling, and storage. Resistance to attrition of the granules is between 90 and 95%. This percentage is based on the following test procedure. A weight of 75 grams of sample is shaken on a 60 mesh screen for ten minutes and 50 grams of the material retained is then shaken in a pan for ten minutes with ten steel balls (5/8" in diameter). The entire sample is then shaken on a 60 mesh screen for ten minutes. The percentage of the original 50 grams retained on the 60 mesh screen is the resistance to attrition cited above. Granular material according to the present invention has been found to generally have a pH between 9.0-9.4. For an agricultural carrier application, pH must be no higher than 8.0. The pH of the agricultural carrier may be lowered by adding a pH lowering additive. Granular material according to the present invention is adapted to absorb various liquids to desired degrees as a function of percentage of weight of the granules. The granular material according to the present invention for use as an agricultural carrier preferably has a liquid holding capacity (LHC) toward chlorobenzene of between 26-29%. The material for use as a floor absorbent, when tested with material retained on an 8×35 mesh, preferably is able to absorb between 73-81% of its weight of water, and preferably between 51-62% of its weight of oil. While this invention has been illustrated and described in accordance with preferred embodiments, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.
In a process for making a granular material from a reject stream from a coated grade waste paper pulp stock recycling process, the pulp stock is screened so that the reject stream passes through a screen and long fibers are retained for use in making paper. Solid material in the reject stream is separated by flotation. Water is removed from the reject stream to increase its consistency to that of modelling clay. The reject stream is supplied to an agglomerator which forms uniform granules of irregular but approximately spherical shape. The granules are then dried so that the granules have a solids content greater than 95%. Apparatus for performing the process and characteristics of granular material formed by the process and apparatus are also described.
3
CROSS-REFERENCE TO RELATED APPLICATION(S) This present application relates to and claims priority from International Patent Application No. PCT/US2010/027193 filed Mar. 12, 2010, and from U.S. Patent Provisional Application Ser. No. 61/159,474, filed on Mar. 12, 2009, the entire disclosures of which are hereby incorporated herein by reference. FIELD OF THE DISCLOSURE Exemplary embodiments of the present disclosure relates generally to measuring properties associated with tissues, and more particularly to non-contact optical system, computer-accessible medium and method for measuring at least one mechanical or material property of tissue using laser speckle. BACKGROUND INFORMATION In many pathological disease processes, the material properties of tissue are altered from a normal state. The development of techniques to measure the mechanical or material properties of tissue can potentially facilitate disease diagnosis and guidance of therapy. The system and methods described in this embodiment can potentially be applied for diagnosis of a variety of disease processes. To describe the technique, in this embodiment it is possible to focus on the cardiovascular applications for the detection of unstable atherosclerotic plaque. Atherosclerotic Plaque Rupture and the Role of Biomechanical Factors: Despite widespread efforts towards its detection and therapy, thrombus mediated ischemic cardiovascular disease still remains the leading cause of mortality in industrialized societies. The rupture of unstable coronary atherosclerotic plaque frequently can precede a majority of ischemic cardiovascular events. The mechanisms leading to plaque rupture can be multi-factorial involving a complex liaison between morphological, compositional, biochemical and biomechanical processes. Due to the cumulative effect of multiple factors, the mechanical stability of the plaque is compromised resulting in an elevated risk of rupture. It is believed that during atherosclerotic plaque progression, the intrinsic mechanical properties of the plaque are serially altered and the measurement of a metric to accurately evaluate intrinsic plaque mechanical properties provides a key determinant of plaque stability. This belief can be based on evidence that mechanical factors greatly influence plaque stability. Hemodynamic forces affect wall shear stresses influencing plaque progression, susceptibility to plaque rupture and coronary thrombosis. 6 Finite element studies have suggested that rupture of the fibrous cap is greatly influenced by regions of high circumferential stress typically in the lateral cap shoulders. The morphology and mechanical properties of the atheroma can affect stress distributions, with plaque rupture frequently occurring in focal regions of high stress concentrations caused by large differences in intrinsic mechanical properties of the fibrous cap and lipid pool. The mechanical properties of the atheroma determine the extent of induced deformation or strain in response to an extrinsic load. Higher strains are measured in lipid rich regions of lower viscosity. Cyclic mechanical strain within the arterial wall affects macrophage gene expression and SMC proliferation. Histology studies have shown the localization of MMP-1 in regions of high circumferential strain within plaques, suggesting that mechanical properties influence MMP release further weakening plaque structure contributing to a greater tendency towards plaque rupture. Image-based methods to measure arterial mechanical properties: A variety of techniques such as intravascular ultrasound (IVUS), virtual histology (VH)-IVUS, magnetic resonance imaging (MRI), angioscopy, thermography, near infrared (NIR) and Raman spectroscopy have been investigated for evaluating coronary plaques in patients. High resolution optical techniques such as optical coherence tomography (OCT) and its next generation implementation, optical frequency domain imaging (OFDI) can provide the opportunity to evaluate plaque microstructure and identify TCFA's in patients. These technologies provide invaluable information on microstructural, compositional and inflammatory factors related to plaque instability and are complementary to approaches that measure mechanical factors. To address the specific need for evaluating mechanical factors, IVUS elastography and finite element analysis (FEA) techniques have been developed. IVUS elastography computes local strains in the arterial wall in response to intra-luminal pressure differentials using cross-correlation analysis and estimation of tissue velocity gradients. Elastography approaches have been applied to OCT to potentially provide higher spatial resolution of strain estimation relative to IVUS. FEA approaches can utilize computer-generated models based on OCT or IVUS cross-sections and estimates of tissue material properties for modeling intra-plaque stress/strain distributions. These techniques provide important information in that they enable the measurement of plaque response to a dynamic external loading environment, thus aiding the investigation of plaque instability. However, the measurement of plaque viscoelasticity using these approaches is intractable, requiring a priori guesstimates of viscoelastic properties, and knowledge of microstructure and loading conditions to solve the inverse problem. Viscoelasticity and Brownian Motion: Tissue is viscoelastic in nature, exhibiting both solid and fluid like characteristics. The mechanical properties of viscoelastic materials can be evaluated by measuring a quantity, termed the “viscoelastic modulus”, which determines the strain induced in the material in response to an extrinsic load. Traditionally, the viscoelastic modulus is measured using a mechanical rheometer, in which a material is loaded between two parallel plates, an oscillatory stress at frequency, ω, is applied and the a strain response is measured to evaluate viscoelasticity. The measured viscoelastic modulus, G*(ω), is expressed as, G*(ω)=G′(ω)+iG″(ω). The real part, G′(ω), is the elastic modulus which defines the elastic solid like characteristics of the material and is the ratio of the elastic component of the oscillatory stress which is in phase with the strain. The imaginary part, G″(ω), provides the viscous modulus and measures the out-of-phase response of the medium defining the material's fluid like characteristics. The ratio between the elastic to viscous moduli provides a measure of ‘phase’, where a lower phase represents a more elastically dominated and a higher phase represents a more viscously dominated material. Studies in the field of polymer rheology have demonstrated non-contact approaches to measure the viscoelastic modulus by evaluating the passive movements (Brownian motion) of particles suspended in a viscoelastic medium. In one publication, it was demonstrated that the Brownian motion of suspended particles is intimately related to the structure and viscoelastic properties of the suspending medium, and particles exhibit larger range of motions when their local environment is less rigid. This indicated that the response of a viscoelastic material to the average Brownian motion of dispersed microscopic particles closely resembles the response of the material to an imposed oscillatory mechanical load at frequency, ω. Consequently, other studies have indicated the use of light scattering techniques to evaluate the viscoelastic modulus of homogenous polymer materials by suspending exogenous particles and measuring the time scale and mean square displacement of microscopic trajectories. By applying these concepts, a further exemplary optical technique can be reviewed, e.g., termed Laser Speckle Imaging, which analyzes the intrinsic Brownian motion of endogenous microscopic light scattering particles that are inherently present within tissue to evaluate tissue viscoelasticity. Laser Speckle Imaging (LSI): When an object is imaged using highly coherent light from a laser, a granular pattern of multiple bright and dark spots becomes apparent on the image, which bears no perceptible relationship to the macroscopic structure of the object. These random intensity patterns, termed as laser speckle, can occur in two situations: (i) when coherent light is reflected from a surface which is rough on the scale of an optical wavelength, and (ii) when coherent light propagates through and is scattered by a medium with random refractive index fluctuations such as in tissue. The interference of light returning from the random surface or medium causes laser speckle. Laser speckle formed from scattering within tissue is exquisitely sensitive to Brownian motion. The Brownian motion of endogenous light scattering particles in tissue causes scatterer locations and optical path lengths to dynamically change resulting in time dependent intensity modulations of laser speckle. The rate of laser speckle modulation can be highly dependent on the extent of motion of suspended scatterers, which is in turn influenced by viscoelasticity of the medium. Consequently, in an atheroma, due to the relatively low viscosity of lipid, endogenous scatterers within the compliant necrotic core exhibit more rapid Brownian motion compared to the stiffer fibrous regions of the plaque. Since scatterer motion governs the modulation of laser speckle, the measurement of temporal intensity variations of laser speckle patterns provides information about the viscoelastic properties of the plaque. Using these principles, the measurement of intensity modulations of time-varying laser speckle patterns can provide a highly sensitive technique for evaluating atherosclerotic plaques. Exemplary procedures using excised atherosclerotic plaques have been reviewed, indicating that the measurement of intrinsic Brownian motion of endogenous particles, related to viscoelasticity, can be used to distinguish plaque type, and evaluate collagen and lipid content. SUMMARY OF EXEMPLARY EMBODIMENTS OF THE DISCLOSURE For example, (a) exemplary embodiments of the LSI techniques and systems according to the present disclosure can be provided for plaque characterization and identification of high-risk plaque, (b) the exemplary LSI time constant can be related to collagen and lipid content, (c) exemplary embodiments of the LSI techniques and systems according to the present disclosure can measure an index of viscoelasticity that can be related to the viscoelastic modulus, G*, (d) fibrous cap thickness can be measured using LSI (e) exemplary embodiments of the LSI techniques and systems according to the present disclosure can identify high-risk plaques during physiological arterial deformation, and (f) the apoE knockout mouse can provide a useful model to evaluate plaque progression. It is likely that exemplary embodiments of LSI techniques and system can provide an exemplary platform for measuring composite metrics of plaque stability based on biomechanical, structural and compositional factors. Exemplary measurements of time constant can be performed by fitting a single exponential to a portion of the normalized speckle decorrelation curve. For example, by evaluating contributions of different time constants using multiexponential analysis of speckle decorrelation, it is possible to increase the efficacy of LSI in investigating plaque heterogeneity. The use of spatio-temporal analysis of exemplary embodiments of the LSI techniques and systems according to the present disclosure in providing depth information has been shown. When combined with beam scanning, this exemplary feature of the exemplary embodiments of the LSI techniques and systems can facilitate the measurement of three-dimensional maps of plaque viscoelasticity and morphology. Studies have shown that the measurement of the mean square displacement of particle trajectories obtained from diffuse light scattering techniques can be used to calculate the viscoelastic modulus in homogenous polymer solutions. These exemplary principles can be applied to determine the intrinsic viscoelastic modulus of tissue components from laser speckle patterns. One of the objects of certain exemplary embodiments of the present disclosure is to provide quantitative indices based on plaque biomechanical properties using LSI to determine the risk of plaque rupture. While certain preliminary studies have successfully demonstrated the capability of LSI in diagnosing plaque type, in order to realize the exemplary objects of the present disclosure, the exemplary embodiment of the LSI techniques and systems can facilitate its use to accurately quantify plaque viscoelasticity. According to one exemplary embodiment of the present disclosure, it is possible to facilitate exemplary methods and systems for measuring the viscoelastic properties of arterial tissue from, e.g., laser speckle images and compare our results with standard mechanical testing measurements. According to another exemplary embodiment of the present disclosure, it is possible to determine changes in plaque viscoelasticity using the exemplary embodiments of the LSI systems and method during different stages of arterial atherosclerotic plaque progression in an atherosclerotic mouse model. Some of the capabilities of LSI that facilitate the measurement of tissue mechanical properties are listed: ♦Exemplary LSI techniques and system can measure intrinsic Brownian motions of endogenous scatterers providing measurements that are intimately linked with the micro-mechanical behavior of the tissue. ♦Exemplary LSI techniques and systems can be implemented using a relatively inexpensive laser source and a high-speed CMOS or CCD camera, enabling the study of tissue viscoelastic behavior ‘in situ’ over a large frequency range over several kHz, defined by the frame rate of the detector. ♦Exemplary LSI measurements can be sensitive to small changes in the viscoelastic properties of the tissue because speckle decorrelation induced by phase shifts in highly scattering media requires very minute displacements of scatterers at length scales smaller than the optical wavelength. ♦Beam scanning enables the unique ability to measure 2D distributions of tissue viscoelastic behavior. ♦High-speed CMOS or CCD technology (˜kHz acquisition) enables speckle decorrelation measurements over very short time scales (few ms) over which the influence of low frequency arterial deformations induced by cardiac (˜1 Hz) or respiratory (˜0.2 Hz) motion is largely mitigated. ♦Exemplary LSI techniques and systems can be utilized implementing small-diameter optical fiber bundles, thus elegantly lending itself for intracoronary applications. It is also possible to apply the exemplary techniques described herein to other optical methods that utilize coherent sources including optical methods such as, e.g., OCT, OFDI, SD-OCT and FD-OCT. The techniques described herein can also be applied to other methods that utilize other coherent radiation sources such as acoustic radiation including ultrasound. Ultrasound speckle patterns can be similarly analyzed to evaluate the viscoelastic properties of tissues by measuring ultrasound speckle decorrelation over finite time durations. Exemplary embodiments of the LSI techniques and systems according to the present disclosure can be accurate for the detection of thin-cap fibroatheromas, and for measuring necrotic core area, fibrous cap thickness and plaque morphology ex vivo. Exemplary LSI techniques and systems according to the present disclosure can be accurate for the detection of thin-cap fibroatheromas, and for measuring necrotic core area, fibrous cap thickness and plaque morphology ex vivo. According to one exemplary embodiment of the present disclosure, it is possible to use such knowledge to measure the viscoelastic modulus, provide technology to conduct intra-arterial LSI in vivo, and derive key biomechanical markers for early detection of high-risk plaques. Indeed, exemplary embodiments of apparatus and method for determining at least one material property of an anatomical structure can be provided. According to one exemplary embodiment, (e.g., using at least one first arrangement) it is possible to apply at least one first coherent radiation to at least one portion of the anatomical structure, and receive at least one second coherent radiation from such portion(s). The first and second coherent radiations can be associated with one another. In addition, (e.g., using at least one second arrangement) it is possible to determine the material property based on the second coherent radiation(s). Such determination can be performed without (i) any portion of an apparatus performing the procedure causing an induction of at least one mechanical deformation on or in the anatomical structure, and/or (ii) any mechanical deformation on or in the anatomical structure. According to one exemplary embodiment of the present disclosure, the first and/or second coherent radiation(s) can be an electro-magnetic radiation. It is possible to scan the anatomical structure at multiple locations, e.g., simultaneously and/or sequentially. It is also possible to detect a scan of the anatomical structure at the multiple locations simultaneously and/or sequentially. In another exemplary embodiment of the present disclosure, the material property can be spatially-varying or depth-varying, as well as an elastic property or a viscous property of the anatomical structure. Further, the material property can be a macroscopic property, a microscopic property and/or a mesoscopic property of the anatomical structure. Such material property can also be a strain on the anatomical structure. According to still another exemplary embodiment of the present disclosure, it is possible (e.g., using the second arrangement) to determine the material property as a function of frequencies of motion of scatterers within the anatomical structure. The motion of the scatterers within the anatomical structure can be a Brownian motion. In a further exemplary embodiment of the present disclosure, the first coherent radiation can be a multiply-scattered light, a single-scattered light, and/or coherent speckle. It is also possible (e.g., using the first arrangement) to apply the first coherent radiation(s) to at least one portion in-vivo. The first and/or second coherent radiation(s) can be an acoustic radiation. These and other objects, features and advantages of the exemplary embodiment of the present disclosure will become apparent upon reading the following detailed description of the exemplary embodiments of the present disclosure, when taken in conjunction with the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Further objects, features and advantages of the present disclosure will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments of the present disclosure, in which: FIG. 1 is an exemplary illustration of speckle patterns acquired from a thin-cap fibroatheroma (TCFA) showing time-dependent fluctuation of laser speckle; FIG. 2(A) is an exemplary graph of Speckle decorrelation curves obtained for three exemplary aortic specimens: TCFA, thick-cap fibroatheroma (TKFA), and fibrous aortic plaques; FIG. 2(B) is an exemplary chart illustrating mean τ computed for different plaque groups under static conditions; FIG. 3 is an exemplary graph illustrating G* measured using a rheometer in response to a oscillatory load at frequencies less than 1 Hz; FIG. 4(A) is an exemplary graph of a spatial heterogeneity in τ obtained by beam scanning over a necrotic core fibroatheroma; FIG. 4(B) is an exemplary graph of the spatial heterogeneity in τ obtained by beam scanning over a calcific plaque; FIG. 4(C) is an exemplary graph of the spatial heterogeneity in τ obtained by beam scanning over a fibrous plaque; FIG. 4(D) is an exemplary map illustrating a distribution of speckle decorrelation time constants over a lesion compared with the accompanying gross pathology; FIG. 5(A) is a graph of τ(ρ) is plotted vs. distance ρ from source; FIG. 5(B) is an exemplary schematic illustration of a photon propagation through a two-layer model; FIG. 6(A) is an exemplary block diagram of an exemplary embodiment of a method according to the present disclosure which can be used to measure and validate sample viscoelasticity using the exemplary LSI techniques; FIG. 6(B) is an exemplary block diagram of an exemplary embodiment of a system according to the present disclosure which can be used to measure and validate the sample viscoelasticity using the exemplary LSI techniques; FIG. 7(A) is an exemplary graph of frequency-dependent complex viscoelastic moduli measured from laser speckle patterns of fat, cartilage and skeletal muscle using the exemplary embodiments of the methods and systems according to the present disclosure; FIG. 7(B) is an exemplary graph of frequency-dependent complex viscoelastic moduli measured from laser speckle patterns of calcific, fibrous and lipid-rich atherosclerotic plaques using the exemplary embodiments of the methods and systems according to the present disclosure; FIG. 8(A) is an exemplary gross pathology photograph of a human aortic segment; FIG. 8(B) is an exemplary map of the distribution of complex viscoclastic moduli measured at high frequency (˜250 Hz) by scanning a focused beam over the human aortic sample shown in FIG. 8(A) ; FIG. 8(C) is an exemplary map of the distribution of complex viscoelastic moduli measured at frequencies ˜100 Hz by scanning a focused beam over the human aortic sample shown in FIG. 8(A) ; FIG. 8(D) is an exemplary map of the distribution of complex viscoelastic moduli measured at lower frequencies ˜10 Hz by scanning a focused beam over the human aortic sample shown in FIG. 8(A) ; and FIG. 9 is an exemplary graph of the spatial variation of speckle decorrelation time constant over a mouse aorta with a fibrous plaque. Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure as defined by the appended claims. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Exemplary Design Measuring viscoelasticity of atherosclerotic plaques: Characterization of Atherosclerotic Plaque using LSI: The exemplary capability of the exemplary embodiments of the LSI systems and methods according to the present disclosure for differentiating atherosclerotic plaque type, and assessing plaque morphology and composition is demonstrated has been described in, e.g., S. Nadkarni, et al., “Characterization of atherosclerotic plaques by laser speckle analysis”, Circulation, 2005. In this publication, 118 aortic specimens were obtained from 14 human cadavers using LSI. Light (632 nm) from a Helium-Neon laser was focused on the luminal surface of the artery, and a CMOS camera captured laser speckle images at 240 frames/s, as shown in FIG. 1 . Time-varying laser speckle images were analyzed using cross-correlation techniques to determine the speckle decorrelation time constant, τ, which is inversely dependent on the rate of change of the speckle image. The plaques were histologically classified into the following groups: thin-cap fibroatheroma (TCFA), thick-cap fibroatheroma (TKFA), pathological intimal thickening (PIT), non-necrotic fibroatheroma (FA), intimal hyperplasia (IH), fibrous plaque, and fibrocalcific plaque (FC). 1 The average speckle decorrelation time constant, τ , was computed for each plaque group. FIG. 2(A) shows examples of the normalized speckle decorrelation curves computed for three aortic plaques. The TCFA demonstrated rapid speckle decorrelation (τ=28 ms) as compared to TKFA (τ=265 ms) and fibrous plaque (τ=540 ms). The average exemplary speckle decorrelation time constant, τ , computed for different plaque groups under static conditions are plotted in FIG. 2(B) . The results of the analysis of variance (ANOVA) and Dunnetts t-tests demonstrated highly significant differences in τ between the plaque groups (p<0.0001). TCFA's exhibited a significantly lower time constant ( τ ˜47 ms) as compared to other lesions due to rapid Brownian motion of endogenous particles within the compliant necrotic core (p<0.001). As a result, the exemplary LSI technique demonstrated high diagnostic sensitivity (100%) and specificity (92%) for identifying TCFA's. Fibrous and fibrocalcific lesions were also easily discriminated from lipid-containing lesions due to their significantly higher time constants. Relationship between plaque composition and laser speckle decorrelation: The time constant, τ, shows high correlation with plaque collagen content (e.g., R=0.73; p<0.0001) when measured using polarized light microscopy of Picrosirius Red (PSR) stained sections. Further, a high correlation between z and minimum cap thickness (R=0.87; p<0.001) and a strong negative correlation (R=−0.81; p<0.0001) between τ and necrotic core area can be obtained. These exemplary results demonstrate that the exemplary LSI measurements of τ can be related to plaque collagen and lipid content. Preliminary studies to evaluate viscoelastic modulus, G: Exemplary preliminary studies have been conducted to evaluate the bulk viscoelastic modulus, G, and its relationship with LSI measurements of τ using in homogenous collagen substrates and arterial plaques and using modeling studies. (The term, bulk viscoelastic modulus, G, can be used to define the overall modulus of the sample which integrates over the sample volume). Homogenous collagen substrate studies: In one example, the exemplary LSI technique was performed on type I collagen gels at varying concentrations (0.2%, 0.3%, 0.4%, 0.6% and 0.8% m/v), and on cartilage disks (type II collagen) obtained from swine knees and ears. In gels, speckle decorrelation time constant, τ, showed high correlation with collagen concentration (R=0.99, p<0.002). Mechanical testing can be performed on all gel and cartilage samples using a Bohlin C-VOR rheometer (Malvern Instruments Inc., MA) to measure G(ω), (0.5<ω<10 Hz). FIG. 3 shows a graph with exemplary mechanical measurements of viscoelastic moduli of collagen gels obtained using a rheometer. In FIG. 3 , τ shows a high correlation with mechanical testing (R=0.97, p<0.0001), establishing a strong relationship between LSI and viscoelasticity. Atherosclerotic plaque studies: In another example, the exemplary LSI technique was conducted by averaging τ values over 4 mm disks of arterial sites, histologically confirmed as calcific, fibrous and NCFA. Mechanical testing was performed using the Bohlin rheometer, and the modulus, G, was measured by averaging G(ω) over the linear range. The G values measured for plaque groups were distinct [2.27×105 Pa (calcific), 3.65×103 Pa (fibrous) and 2.23×103 Pa (NCFA)], and LSI measurements of τ correlated well with G (R=0.99, p<0.001). The above exemplary results indicate a close relationship between LSI measurements of τ and G(ω) measured by mechanical testing. For all plaques, G was approximately equal to the elastic modulus, G′, suggesting that the plaques were largely elastic in the measurement regime with a small viscous modulus, G″. These values correspond with previously published reports.39 ANOVA tests showed statistically significant differences in G for the three plaque types (p<0.001). Modeling Analysis: To evaluate the effect of depth dependent variations in plaque viscoelasticity on the bulk viscoelastic modulus, the atherosclerotic plaque can be modeled as a multilayered cylinder of thickness, L and viscoelastic modulus, G. For the purpose of this exemplary model, the assumption that G≈G′ can be made, which can be supported by ex-vivo exemplary analysis above. As an initial matter, the case of a NCFA can be considered, consisting of a fibrous cap layer of thickness L 1 with modulus G 1 , overlying lipid pool layer of thickness L 2 with modulus G 2 , loaded between the parallel plates of a rheometer. The twisting moment M applied by the rheometer can be determined by the distribution of shear stresses, T, integrated across the cylinder of cross-sectional area, A. The moment, M, is given by: M = ∫ rt ⁢ ⅆ A = G ⁢ ⅆ φ ⅆ z ⁢ I z ( C1 ) where I z =∫r 2 dA is the polar moment of inertia and φ is the angular displacement in the sample. Since the moment M=M 1 =M 2 for each layer, by evaluating equation (C1) for each layer of thickness L 1 and L 2 , and for the entire cylinder, L we deduce the expression: G = LG 1 ⁢ G 2 L 1 ⁢ G 2 + L 2 ⁢ G 1 ( C2 ) Equation (C2) shows that the overall bulk viscoelastic modulus of the plaque is related to the thickness and viscoelastic modulus of each layer. This equation (C2) can be applied to evaluate the relationship between the bulk modulus G and fibrous cap thickness in a NCFA, using previously reported values of G 1 =496 kPa, and G 2 =222 kPa, for fibrous and lipid rich tissue and evaluated the influence of varying fibrous cap thickness (e.g., 0-500 μm) on G (as shown in FIG. 3 ). This exemplary model can be extended to include multiple layers of varying depth-dependent viscoelasticity by using the generalized equation: L G = ∑ n ⁢ L i G i ( C3 ) These analyses suggest that the fibrous cap thickness greatly influences the bulk viscoelasticity of the plaque (see FIG. 3 ), indicating that the measurement of the bulk viscoelastic modulus can potentially provide a quantitative metric to evaluate plaque stability. Measuring tissue heterogeneity using Exemplary LSI Systems and Techniques: In the exemplary analyses described above, bulk viscoelasticity can be evaluated over the entire speckle image by illuminating a single location. Thus, the Brownian motion was integrated over the illuminated volume and information about tissue heterogenity was lost. These exemplary analyses have provided significant evidence to show that measuring bulk viscoelasticity alone can provide an important metric related to plaque stability. However, evaluation of compositional and structural heterogeneities provides additional information about the risk of rupture. Exemplary analyses described below determine the feasibility of in evaluating both, (i) spatial, and (ii) depth-dependent heterogeneities in viscoelastic properties using laser speckle. Laser speckle to evaluate spatial (or transverse) heterogeneity: Laser speckle images can be obtained by scanning the laser beam at small spatial increments and the spatial distribution of τ can be measured across the plaque. FIGS. 4(A)-4(D) illustrate the transverse spatial variation of τ as a function of beam location. As the beam was scanned across each lesion, τ varied significantly depending on tissue type: τ was low (20-50 ms) in the necrotic core regions 405 (see graph 400 —shown in FIG. 4(A) ) and higher in the calcific 415 (˜2200 ms as shown in graph 410 in FIG. 4(B) ) and fibrous 425 (˜800 ms as shown graph 420 in FIG. 4(C) ) regions. FIG. 4(D) illustrates a two-dimensional map 435 of the spatial distribution of τ, measured by scanning the beam at 300 μm increments across a lipid-rich plaque: a well-demarcated region 430 of low τ relative to the surrounding aortic tissue is seen. These exemplary results show that beam scanning can be utilized to evaluate spatial variation in plaque viscoelasticity to potentially detect heterogeneities such as calcific nodules and localized necrotic cores. Laser speckle to evaluate depth heterogeneity: Due to the diffusive properties of light propagation in tissue, photons returning from deeper regions have a higher probability of remittance farther away from the illumination location. While beam scanning can provide information about spatial heterogeneities, depth-dependent heterogeneities can be measured by analyzing variation in τ as a function of radial distance, ρ, from the illumination location in each speckle image. An exemplary embodiment of the method and system according to the present disclosure can be provided to obtain depth-dependent measurements by combining spatio-temporal laser speckle analysis with diffusion theory and Monte Carlo models of light propagation. Such exemplary method and system can be used to measure fibrous cap thickness in necrotic-core fibroatheromas (NCFA's), which can also be applied to evaluate depth-dependent viscoelasticity. For example, laser speckle patterns of 20 NCFA's were analyzed and spatio-temporal speckle fluctuations were measured by exponential fitting of the windowed normalized cross-correlation of sequential speckle patterns to obtain τ(ρ). By analyzing the spatial variation in τ(ρ) the distance, ρ′, can be obtained at which τ(ρ) dropped to 65% of its maximum value. FIG. 5(A) shows a graph of τ(ρ) plotted vs. distance ρ from source and FIG. 5(B) shows an exemplary schematic illustration of a photon propagation through a two-layer model. For example, FIG. 5(A) shows that τ(ρ) is plotted vs. distance ρ from source. At distances <ρ′, e.g., most photons traverse the fibrous cap and τ(ρ) is high. At distances >ρ′, e.g., a majority of photons traverse the necrotic core and τ(ρ) is low. A Monte Carlo look up table can be created to relate radial distance, ρ, across the speckle pattern to the maximum photon penetration depth, z max (ρ), through the plaque. To measure cap thickness, the depth z max (ρ′), can be evaluated at ρ=ρ′, that highly correlated with histological measurements (R=0.78, p<0.0001). Paired t-tests showed no significant difference from histological measurements (p=0.4). These exemplary findings indicate the possibility of measuring spatial and depth-dependent viscoelasticity using LSI, potentially providing insight into structural and compositional heterogeneities. Validation of Exemplary Methods to Measure the Viscoelastic Properties of Arterial Tissue from Laser Speckle Images Overview: Measurement of Viscoelastic Properties Using Laser Speckle An exemplary embodiment of the method, computer-accessible medium and system to measure viscoelastic properties of atherosclerotic plaques from laser speckle images can be based on previously-established optical methods. For example, using certain dynamic light scattering techniques, a quantity termed the mean square displacement (MSD), Δr 2 (t) , can be measured which provides an assessment of scatterer motion such as Brownian motion in the tissue. The MSD can be related to the material's frequency-dependent viscoelastic modulus, G*(ω). To probe the mechanical properties of highly scattering media such as colloids and polymer gels, Diffuse Wave Spectroscopy (DWS) techniques can be utilized. With the exemplary DWS techniques, a laser beam can be provided incident on the sample and light scattered multiple times is collected using a single optical fiber in transmission or backscattering geometry. To measure the Brownian motion dynamics of the ensemble of particles within the medium, the time-varying intensity fluctuations over a single speckle spot can be measured by averaging over several cross-correlation functions that evolve in time to obtain the function, g 2 (t). The ensemble speckle cross-correlation function, g 2 (t), can be used to measure the MSD and the resulting elastic, G′(ω), and viscous, G″(ω), moduli and the resulting complex modulus G*(ω). These exemplary methods have been demonstrated in the field of polymer rheology to measure the viscoelastic properties of homogenous materials such as semiflexible actin gels, polyacrylamide networks and other complex fluids. In standard DWS, since g 2 (t) is measured over a single speckle spot, data acquisition time is several orders of magnitude larger than the typical time scale of fluctuations (e.g., acquisition time of several minutes) which can be impractical for materials that exhibit slower particle dynamics. Advances in DWS technology have described the use of CCD cameras to simultaneously acquire multiple speckles over the sample (“multispeckle” DWS). This exemplary technique enhances the statistical accuracy in determining the MSD by simultaneous ensemble averaging of multiple speckle spots, significantly reducing the data acquisition time to a few ms. Previous analyses in polymer rheology indicated that g 2 (t) functions measured using ‘multispeckle DWS’ and standard DWS show high agreement with an error <about 2%. With the results from the exemplary “multispeckle” DWS techniques to measure polymer viscoelasticity, it is possible to apply these exemplary techniques to evaluate the viscoelastic properties of human tissue, e.g., atherosclerotic plaques. The term “LSI” as used herein can be similar to the “multispeckle” DWS described in polymer rheology applications, but certainly not limited thereto. For plaque measurements, the evaluation of two-dimensional speckle images (e.g., in the exemplary LSI techniques and systems) instead of a single speckle spot (e.g., in standard DWS) can be advantageous as it can provide more complete information about tissue viscoelastic properties, and facilitate depth-resolved measurements potentially enabling the evaluation of important parameters such as the thickness and viscoelasticity of the fibrous cap and necrotic core. The exemplary procedures of such methods to provide and validate the measurement of plaque viscoelasticity using the exemplary embodiments of the LSI techniques and systems according to the present disclosure is shown in the block diagram of FIG. 6(A) . For example, as shown in FIG. 6(A) , time varying laser speckle images can be acquired at high frames (block 610 ). Then, in block 620 , such time-varying laser speckle images acquired at high frame rates can be analyzed using exemplary cross-correlation techniques to obtain the speckle decorrelation curve, g 2 (t). The MSD of particle motions such as Brownian motion can be estimated or measured from the speckle decorrelation data (block 630 ). Parameters that characterize the medium scattering properties required to estimate the MSD can be evaluated from time-averaged laser speckle images (block 660 ) and by using diffusion theory and Monte Carlo simulations of light propagation through the sample (block 665 ). The viscoelastic or complex modulus, G*(ω) and the elastic, G′(ω) and viscous, G″(ω) moduli can be derived (block 640 ) and compared with standard mechanical testing measurements (block 650 ). Exemplary LSI System and Instrumentation An exemplary embodiment of the LSI system according to the present invention can be provided to acquire laser speckle images, as shown in FIG. 6(B) . For example, light from an unpolarized Helium Neon light source 670 (e.g., 632 nm, 30 mW) can be coupled into an optical fiber arrangement 675 , such as a single-mode fiber. The beam can be expanded by, e.g., 5:1, reflected off a galvanometer-mounted mirror 680 , and focused to, e.g., a 50 μm diameter spot on the surface of a sample 685 . The galvanometer-mounted mirror 680 can be computer-controlled by a computer 690 to facilitate scanning the illumination beam across the sample 685 . It is also possible to illuminate the tissue surface of the sample 685 using a larger diameter extended beam or a collimated beam. At the collection end of the exemplary system, a collection arrangement 695 , such as, e.g., a high-speed, digital CCD or CMOS camera (e.g., Mikrotron MC 1310) configured to acquire speckle patterns at high frame rates may be provided and images can be transferred to the computer 690 in real time. Time-varying cross polarized laser speckle images can be acquired from imaging sites on the tissue sample 685 . Exemplary Laser Speckle Image Analysis: Measurement of Mechanical Properties Such as Viscoelastic Moduli Exemplary acquired time-varying laser speckle patterns can be analyzed using cross-correlation techniques to determine the speckle cross-correlation function, g 2 (t). The normalized 2D cross-correlation of the first speckle image with each image in the time-varying image series can be determined using the exemplary embodiments of the present disclosure. The maximum value of normalized cross-correlation can be determined and plotted as a function of time over the acquisition duration to obtain the g 2 (t) curve for each tissue sample. To measure the viscoelastic properties of the sample, the g 2 (t) curve can be evaluated to obtain the MSD and the resulting elastic, viscous and complex moduli. The ensemble speckle cross-correlation function, g 2 (t), can be expressed in terms of the MSD, Δr 2 (t) , of scattering particles as follows, g 2 ⁡ ( t ) - 1 = [ ∫ 0 ∞ ⁢ ⅆ sP ⁡ ( s ) ⁢ exp ⁡ ( - ( s / 3 ⁢ I * ) ⁢ k 2 ⁢ 〈 Δ ⁢ ⁢ r 2 ⁡ ( t ) 〉 ) ] 2 ( D1 ) where P(s) is the distribution of photon trajectories traversing a path length, s, and k=2πn/λ, is the wave number of light in a medium where n is the refractive index and λ, the wavelength of light. The mean free path, I*, can characterize the scattering medium and is defined as the distance a photon travels before its direction is completely randomized. The exemplary embodiment of a method according to the present disclosure that can be used to estimate the parameters, P(s) and I*, preferable to calculate the MSD in equation (D1) is described below. For example, it is possible to utilize the exemplary mathematical methods that have been derived and established in previous DWS analyses in homogenous polymers to measure G*(ω). In these exemplary methods, a modified algebraic form of the generalized Stokes-Einstein equation directly relates the MSD of probe particles to the frequency dependent viscoelastic modulus, G*(ω), of the material (equation. D2).  G * ⁡ ( ω )  = kT π ⁢ ⁢ a ⁢ 〈 Δ ⁢ ⁢ r 2 ⁡ ( 1 / ω ) 〉 ⁢ Γ ⁡ [ 1 + α ⁡ ( ω ) ] ⁢ ❘ t = 1 / ω ( D ⁢ ⁢ 2 ) where G*(ω) is the frequency dependent complex viscoelastic modulus, a is the scatterer size, Γ is the gamma function, and Δr 2 (1/ω) is the magnitude of the MSD at t=1/ω. The value of α(ω) can be given by: α ⁡ ( ω ) = ⅆ ln ⁢ 〈 Δ ⁢ ⁢ r 2 ⁡ ( t ) 〉 ⅆ ln ⁢ ⁢ t ⁢ ❘ t = 1 / ω ( D3 ) The particle size, a, is the characteristic length scale probed and can be given by, a ≈ 1 k 2 ⁡ ( z o / I * + 2 / 3 ) 2 ( D4 ) where z o is the penetration depth. From previous studies it is estimated that z o ≈0.6ρ in arterial tissue, where ρ is the radial distance on the 2D speckle image measured from the central illumination location. Average particle sizes of different tissue types can also be estimated using an iterative process by G*(ω) using a mechanical rheometer, and retrospectively deducing particle size, a, values using equation (D2). This a priori estimate of particle size can then be applied to measure viscoelastic properties from laser speckle patterns for prospective measurements of tissue samples. The elastic, G′(ω), and viscous, G″(ω), moduli can be determined using the following relations: G ′(ω)=| G *(ω)|cos(πα(ω)/2) G ″(ω)=| G *(ω)|sin(πα(ω)/2)  (D5) These exemplary relations can provide a direct physical representation of how the elastic modulus and viscous modulus of the material depend on the MSD. In a purely viscous medium, α≈1 resulting in a dominant loss modulus, and in a purely elastic medium α≈0 and the elastic modulus dominates. Exemplary Estimation of Parameters: P(s) and I* The exemplary evaluation of the MSD techniques of probe particles from the g 2 (t) function as expressed in equation (D1) can utilize the measurement of the distribution of photon trajectories, P(s), traversing a path length s, and the mean free path, I*. The parameters, P(s) and I* which characterize the optical properties of scattering medium can be derived from time-averaged speckle images using previously described methods. It is possible to determine optical properties of human tissue by combining a diffusion theory model of spatially-resolved diffuse reflectance 58 and a Monte-Carlo model of light transport in tissue. According to one exemplary embodiment of the present disclosure, it is possible to utilize these exemplary methods to obtain the parameters, P(s) and I*. The sample can be described by its optical parameters: the absorption coefficient, μ a , the scattering coefficient, μ s , and the anisotropy coefficient, g, as well as the refractive indices of air and tissue (n=1.4) First, it is possible to derive the optical properties of the sample by measuring the radially dependent remittance from the sample. Apriori estimates of tissue optical properties can also be used. Time-varying speckle images of the fibrous plaque can be obtained using the imaging the exemplary embodiment of the system and method according to the present disclosure as described herein. Given the quantum efficiency and gain of the CCD camera, the total number of diffuse photons remitted from the plaque and detected by the CCD sensor can be measured by time-averaging speckle images acquired over a time duration of a few seconds or longer. The radially-resolved photon probability, P(ρ), for the fibrous plaque can be generated by summing the number of photons detected over different annuli of radii ρ, and then normalizing this value by the total number of photons detected over the area of the detector. Further, the theoretical radial photon probabilities determined from a single-scatterer diffusion model for the case of a semi-infinite homogeneous tissue 58 can be fitted to the measured radial photon probabilities, P(ρ), using a least-square optimization procedure, to extract the optical properties, μ a , μ s and g, of the sample. The mean free path, I*, can be then evaluated for the scattering medium, which is given by I*=1/μ a (1−μ s ). When the optical properties are established, they can be used as inputs to a Monte Carlo model which assumes a semi-infinite homogenous layer. 49 Photon initial conditions can include input beams perpendicular to the semi-infinite layer. Multiple runs can be performed with the same set of optical properties and photon packet trajectories can be launched. Remitted photons can be collected over a radial distance of a few mm. From the output of the Monte Carlo simulations, the maximum path length, s, traversed by each photon can be recorded and the path length distribution, P(s), of photons can be measured. The parameters, P(s) and I*, can be input into equation D1 to determine the MSD of probe Brownian motion in the sample. Exemplary Methods Exemplary LSI system optics: Optics for light delivery and speckle image transmission can be designed and optimized using, e.g., ZEMAX (ZEMAX Development Corporation). A variety of different lenses can be simulated and optimization can be performed to minimize aberrations through different optical window designs and to increase field of view. Following the optimized design and selection of configuration and components, optical elements can be obtained. The laser, illumination and collection optics, optical fibers, CCD camera, galvanometer-controlled mirror, linear translation device, and computer can be integrated in a portable cart. Software can control the motors, reading and storing motor encoder positions, laser speckle analysis, and displaying data in a various formats for ease of interpretation. Exemplary Collagen Phantom Preparation for LSI Since Type I collagen can be a predominant constituent of the extracellular matrix in atherosclerotic plaques, test phantoms can be made using commercially available collagen to evaluate the performance of LSI in measuring sample viscoelasticity. Collagen gels (Type I) can be constructed from rat tail tendon collagen dissolved in 0.02N acetic acid (8 mg/ml) (BD Biosciences, catalog no. 354249). Latex microspheres with a diameter of about 0.3 μm (10% in water) can be used as light scattering probes. To evaluate the influence of collagen concentration on the measured viscoelastic modulus, collagen gels can be constructed with at each collagen concentration of 0.7%, 0.5%, 0.3%, 0.2%, and 0.1% (mass/volume). Since collagen can dissolve only in an acidic medium, and forms gels only in a neutral medium of pH from about 7 to 8, a high pH buffer can be used to neutralize the acetic acid in the collagen solution. A high pH buffer can be used. Exemplary Coronary Atherosclerotic Plaque Specimens Cadaveric coronary arterial segments can be excised during autopsy, and slit longitudinally open to expose the luminal surface. The coronary segments can be immersed in phosphate buffered saline and warmed to 37° C. before imaging. Exemplary Laser Speckle Imaging of Samples Time-varying laser speckle images of the coronary arterial specimens and collagen gel phantoms can be obtained over a measurement duration of about 1s, according to one exemplary embodiment of the present disclosure. For example, each sample can be stabilized on a cork-board, clamped onto an L-brackets mounted on a linear motorized stages. The L-brackets can be immersed in a PBS bath maintained at about 37° C. such that the luminal surface of the artery (or surface of the collagen gel) is exposed just above the level of PBS. In the exemplary arterial specimens, time-varying laser speckle images can be obtained at randomly selected discrete lesion sites along the segment. Each imaging site can be marked with two India ink spots marking the diameter of the speckle pattern over the lesion, to facilitate accurate registration with mechanical testing measurements and histopathology. Circular sections can be cut across the artery at each marked imaging site using a 2 mm circular punch biopsy too and stored in, e.g., PBS. In the collagen gel phantoms laser speckle images can be obtained three randomly selected sites for each gel to evaluate heterogeneity. In all samples, the frequency-dependent viscoelastic modulus, G*(ω), can be computed at each spatial location from the time-varying laser speckle images using techniques described above. Following LSI, the samples can be prepared for standard mechanical testing procedures. Exemplary Mechanical Testing Mechanical testing to measure the viscoelastic properties of the coronary arterial specimens and collagen gel phantoms can be performed using a Bohlin C-VOR computer-controlled mechanical rheometer (e.g., Malvern Instruments, Southborough, Mass.). An exemplary embodiment of the system according to the present disclosure can include two parallel plates that can hold the sample affixed to the bottom plate to prevent slipping. A shear stress can be delivered to the sample by the motor via an oscillatory torque applied to the top plate. The resultant strain in the sample can be measured by an angular position sensor incorporated in the exemplary system and automated Bohlin system software can calculate G*(ω), G′(ω) and G″(ω). The mechanical testing can be conducted at, e.g., about 37° C. In the first stage of mechanical testing, a gradually increasing stress can be applied and the strain response can be recorded. The resultant viscoelastic modulus, G*, can be plotted as a function of measured strain to determine the range of linear strain response over which G* is independent of strain to provide an estimate of the mechanical strength of each sample. The threshold strain, γ max , can be determined above which the sample's intermolecular forces are overcome by the stress and the sample viscoelastic modulus falls. In the second stage of mechanical testing, an oscillatory strain can be induced in the sample swept through a frequency range, 1<ω≦100 Hz. The maximum strain can be maintained at γ max . The lower limit of the frequency range can be determined by the imaging time (1 s) over which the exemplary LSI techniques is performed and the upper limit, ω=100 Hz, can be limited by, e.g., the maximum frequency limit of the Bohlin rheometer system. The frequency dependent viscoelastic, G*(ω), elastic, G′(ω) and viscous, G″(ω), modulii can be recorded for each sample. Exemplary LSI measurements of viscoelastic moduli performed in the coronary specimens and collagen gel phantoms can be compared with mechanical testing and Histological measurements of plaque collagen content. Exemplary results are shown below: Single location measurements: Using the exemplary methods described herein, in one example, the techniques above were applied to measure viscoelastic moduli from laser speckle patterns of animal tissue specimens such as cartilage, muscle and fat. In this example, the overall “macro” viscoelastic modulus of bulk tissue within the illuminated volume can be measured from the MSD data determined over the entire speckle pattern obtained by focusing the beam to a 50 μm spot. The exemplary results are shown in FIG. 7A which illustrates the bulk viscoelastic moduli measurements plotted as a function of frequency measured from laser speckle patterns of cartilage 700 , skeletal muscle 705 , and adipose fat at temperatures of 4° C. 710 and 40° C. 715 . The exemplary results indicate that cartilage 700 has highest modulus values compared to skeletal muscle 705 and adipose fat 710 , 715 . Additionally, temperature influences sample viscoelasticity evidenced here by a lower modulus measured for adipose fat at 40° C. 715 compared to that at 4° C. 710 . In another example, the exemplary techniques described herein above were applied to human atherosclerotic plaques. FIG. 7B shows the exemplary LSI measurements of plaque viscoelasticity obtained from human atherosclerotic plaques. The results demonstrate that higher moduli measurements were measured for the calcific plaques 720 and fibrous plaques 725 compared to the lipid-rich plaque 730 . At higher frequency regions of the G(ω) plot, the viscoelastic modulus of fibrous plaque 725 was significantly higher than lipid rich tissue 730 compared to the lower frequency regions. Viscoelasticity mapping: While laser speckle patterns obtained by beam focusing (as described above) can provide information about tissue viscoelasticity over the illuminated volume, scanning a collimated or focused beam over a sample can facilitate the evaluation of spatial heterogeneities in viscoelastic moduli. For example, FIGS. 8(A)-8(D) show an example of two-dimensional maps of the frequency dependent modulus, G(ω), measured by scanning a 5 mm collimated beam over a 5 cm region of a human cadaveric artery. In this case, G(ω) values were computed from MSD data measured within overlapping windowed regions of 100×100 μm over the artery. Two-dimensional maps of G(ω) can be obtained by performing an interpolation over the region of interest. In FIGS. 8(B)-8(D) , G(ω) maps computed at different frequencies are plotted, respectively, and compared with a gross pathology photograph ( FIG. 8(A) ) of the artery, in which calcific regions 800 , fibrous regions 805 and lipid-rich regions 810 are demarcated. The India ink spot 815 is also visible in the maps, and can used for accurate registration of the G(ω) maps with the gross pathology image. As seen in G(ω) plots, at higher frequencies the calcific tissue types 820 , fibrous tissue types 825 and lipid-rich tissue types 830 are distinguished by significant differences in their viscoelastic moduli. At lower frequencies (shown in FIGS. 8(C) and (D)), G(ω) differences between fibrous and lipid-rich tissue types are not highly significant. These exemplary results demonstrate the ability to measure heterogenous moduli by beam scanning simultaneously over a large range of frequencies using a non-contact optical approach. Another exemplary method to accomplish two-dimensional mapping of tissue viscoelastic moduli can be performed by illumination using an extended beam and the resulting speckle patterns can be analyzed by employing windowed over a varying range of scales (microscopic, mesoscopic and macroscopic), of g 2 (t) over a single speckle spot or multiple speckle spots over the illuminated tissue. Thus, it is possible to evaluate tissue viscoelastic moduli over a varying range of scales (microscopic, mesoscopic and macroscopic). Exemplary Method to Monitor Changes in Tissue Mechanical Properties During Disease Progression: Changes in Arterial Viscoelastic Properties Using LSI During Plaque Progression in a Mouse Model of Atherosclerosis For example, mechanical strength of the plaque, determined by the viscoelastic modulus, G*, can be modified and compromised during plaque progression. By monitoring G* during different stages of atherogenesis, quantitative biomechanical markers can be used to evaluate the risk of rupture. Exemplary Monitoring Changes in Arterial Viscoelasticity During Plaque Progression It is possible to use the exemplary methods according to the present disclosure as described herein above to monitor arterial viscoelastic moduli during different stages of atherosclerosis progression in a murine model. For example, it is possible to evaluate the influence of multiple factors on the arterial viscoelasticity specifically: stage of atherogenesis (imaging time point), plaque type and blood cholesterol. Mice on a high fat diet can be investigated at four imaging time points. LSI of murine aortic, brachiocephalic, carotid arteries and the iliac bifurcation can be conducted. Time-varying laser speckle images can be analyzed to measure arterial viscoelastic moduli. Arterial viscoelasticity can be serially monitored at each imaging time point and compared with Histopathological findings at sacrifice. Further Exemplary Methods Below, exemplary embodiments of the methods and systems according to the present disclosure to evaluate and monitor arterial viscoelastic properties during atherosclerosis progression in atherosclerotic mice can be utilized. Exemplary Mouse Model of Atherosclerosis Exemplary use of atherosclerotic mouse model: An atherosclerotic mouse model using Apolipoprotein E knockout (ApoE −/−) mice (background strain—C57BL/6) can be used to review this exemplary embodiment. This exemplary model can be based on previous analyses which indicated that advanced necrotic core plaques resulting in plaque rupture occurred in apoE-knockout mice after 8 weeks of fat feeding. The exemplary LSI analyses can be implemented to (i) evaluate the use of apo E−/− mice to evaluate plaque progression, and (ii) to test the feasibility of measuring viscoelasticity of mouse arteries using laser speckle techniques. The apolipoprotein E knockout (ApoE −/−) murine model has been shown to be a reliable and reproducible model for atherosclerosis, and its lesion characteristics are similar to those associated with plaque instability in humans. The feasibility of measuring arterial viscoelasticity of aortic plaques can be assessed in apo E−/− mouse arteries. In one study, segments of the abdominal aorta were obtained from a fat fed apo E−/− mouse at 14 weeks. For example, an exemplary LSI procedure was conducted by scanning a focused (20 μm) beam (632 nm) and measuring τ, at 300 μm increments along the length of the aorta. FIG. 9 shows the spatial distribution of τ 900 co-registered with the corresponding gross pathology photograph of the mouse aorta 905 , and measured by beam scanning which shows evidence of fibrous plaque with varying mechanical properties. The τ value varied significantly and was higher in region corresponding the location of the plaque (τ=462 ms) suggesting the presence of a fibrous plaque. Lower τ values adjacent to the fibrous plaque may be attributed to hyperlipidemia in the apo E−/− mouse. This exemplary data indicates that by beam focusing in conjunction with scanning, the exemplary LSI technique and system according to the present disclosure can detect plaques in mouse arteries Multiple mice can be used; for example, 48 C57BL/6 ApoE −/− and 12 regular C57BL/6 mice (control) can be studied. Starting at about 6 weeks of age, the 48 ApoE −/− mice can be placed on a high fat diet (e.g., 0.2% cholesterol, 21% fat, Harlan Tekland #88137) and 12 control mice continued on a regular chow diet (0% cholesterol, 5.7% fat, Harlan Tekland #2018). For example, the first imaging time point can be at 6 weeks after initiation of the high fat diet. At each time point, 12 ApoE −/− and 3 control mice can be randomly selected and sacrificed. The mouse vasculature can be prepared for imaging and LSI measurements along with corresponding Histopathology can be performed on each animal (as described below). Subsequently, the second, third and forth imaging time point can be, e.g., at 12 weeks, 18 weeks and 24 weeks after initiation of the high fat diet. LSI and Histopathological measurements can proceed in the manner described for the first imaging time point. At each imaging time point, blood samples can be drawn from both ApoE −/− and control mice, and total cholesterol can be determined enzymatically. The exemplary sites of lesion prediliction in the apoE −/− mouse aorta are shown in FIG. 9 . Exemplary Laser Speckle Imaging of Mouse Vasculature Development of atherosclerotic lesions in the vasculature of mice can occur at reproducible sites which are predominantly dictated by heinodynamic forces experienced by the endothelium. Thus, it is possible to select arterial segments in the mouse vasculature to conduct LSI to coincide with arteries exhibiting plaque predilection. The aorta (including the ascending, thoracic and abdominal aorta), brachiocephalic trunk, right and left common carotids and the iliac bifurcation can be imaged using for LSI. Similarly, the brachiocephalic trunk, and the left and right common carotid arteries can be imaged in 1 mm increments advancing from the aortic arch towards the carotid bifurcation. Time-varying laser speckle images can be obtained at high frame rates at each imaging site over a measurement time duration determined using the exemplary embodiments described herein above. Exemplary Histological Processing and Analysis Following the exemplary imaging, the arterial segments can be fixed in about 10% formalin, embedded and sectioned using standard Histology techniques. Cross-sectional sections (thickness=4 μm) can be cut over the length of each aortic, brachiocephalic and common carotid arteries. The sections can be stained with H & E and Trichrome stains, and interpreted by a pathologist blinded to the LSI data. Atherosclerotic lesions and the natural history of their progression in the apoE-knockout mouse bear a resemblance to atherogenesis in humans. Fatty streaks are present in early stages and as lesions progress multilayered appearances occur showing presence of smooth muscle cells. Advanced lesions indicated fibrous cap appearance, necrotic core, cholesterol clefts and calcifications. Spontaneous plaque rupture has been shown in fat fed mice with the fibrous cap significantly thinner in ruptured lesions than intact lesions. Due to the similarities with human atherosclerosis, it is possible to characterize atherosclerotic lesions in apoE-knockout mice based on the classification scheme proposed by Virmani et al. Atherosclerotic lesions can be classified into the following six groups: intimal xanthoma (or fatty streak), intimal thickening (IT), necrotic core fibroatheroma (NCFA), ruptured plaque, fibrous plaque and calcific plaque. Exemplary Statistical Analysis Exemplary time-varying laser speckle images obtained from the mouse vasculature can be evaluated using the exemplary techniques described herein above. The frequency dependent viscoelastic modulus, G*(ω), can be measured from the mean square displacement of plaque particles which will determined from the speckle cross correlation curve, g 2 (t). The value of the viscoelastic modulus, G* at the optimal frequency, ω, (as described herein above) can be recorded from the G*(ω) data. Based on histological diagnoses, the G* value associated with each lesion can be assigned to one of six classified plaque groups for each of the four imaging time points. For each plaque type, the G* data can be expressed as G* ±s G *, where G* is the average viscoelastic modulus computed for each plaque group at each imaging time point and s G * is the standard deviation. Multiple factors can influence the viscoelastic modulus, G*. For example, the influence of following factors on G* can be evaluated: number of weeks on high fat diet, plaque type, animal within each plaque group, and blood cholesterol at each time point. The differences between G* measurements influenced by these factors can be evaluated using three-way analysis of co-variance tests. The three factors included in the analysis can be: imaging time point, plaque type, and animal within each plaque group. To determine whether blood cholesterol is a determining factor that influences the value of G*, the covariate in these tests can be the measured blood cholesterol level at each imaging time point. Statistical significance to elucidate differences in G* measurements for the tests can be defined by a p-value <0.05. Fibrous cap thickness in the NCFA group can be determined from digitized Trichrome-stained histology sections. The relationships between G* and fibrous cap thickness in the NCFA set can be investigated using linear regression. The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Indeed, the arrangements, systems and methods according to the exemplary embodiments of the present disclosure can be used with and/or implement any OCT system, OFDI system, SD-OCT system or other imaging systems, and for example with those described in International Patent Application PCT/US2004/029148, filed Sep. 8, 2004 which published as International Patent Publication No. WO 2005/047813 on May 26, 2005, U.S. patent application Ser. No. 11/266,779, filed Nov. 2, 2005 which published as U.S. Patent Publication No. 2006/0093276 on May 4, 2006, and U.S. patent application Ser. No. 10/501,276, filed Jul. 9, 2004 which published as U.S. Patent Publication No. 2005/0018201 on Jan. 27, 2005, and U.S. Patent Publication No. 2002/0122246, published on May 9, 2002, the disclosures of which are incorporated by reference herein in their entireties. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present disclosure. In addition, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it is explicitly being incorporated herein in its entirety. All publications referenced herein above are incorporated herein by reference in their entireties.
Exemplary embodiments of apparatus and method for determining at least one material property of an anatomical structure can be provided. According to one exemplary embodiment, it is possible to apply at least one first coherent radiation to at least one portion of the anatomical structure, and receive at least one second coherent radiation from such portion(s). The first and second coherent radiations can be associated with one another. In addition, it is possible to determine the material property based on the second coherent radiation(s). Such determination can be performed without (i) any portion of an apparatus performing the procedure causing an induction of at least one mechanical deformation on or in the anatomical structure, and/or (ii) any mechanical deformation on or in the anatomical structure.
0
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This patent application claims benefit from U.S. Provisional Patent Application Ser. No. 60/206,878, filed May 24, 2000, which application is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to microscale devices for performing analytical testing and, in particular, to surface tension valves for controlling flow within microfluidic channels. [0004] 2. Description of the Prior Art [0005] Microfluidic devices have recently become popular for performing analytic testing. Using tools developed by the semiconductor industry to miniaturize electronics, it has become possible to fabricate intricate fluid systems which can be inexpensively mass produced. These techniques may be used to enable the development of miniaturized fluidic circuits as building blocks for an advancement in the fields of medical diagnostics and chemical analysis. [0006] One aspect of microfluidics technology is based on the very special behavior of fluids when flowing in channels approximately the size of a human hair. This phenomenon, known as laminar flow, exhibits very different properties within a microscale channel than fluids flowing within the macro world of everyday experience. Due to the extremely small inertial forces in microscale structures, practically all flow in microfluidic channels is laminar. This allows the movement of different layers of fluid and particles next to each other in a channel without any mixing, except for diffusion. [0007] Microfluidic technology can be used to deliver a variety of in vitro diagnostic applications at the point of care, including blood cell counting and characterization, and calibration-free assays directly in whole blood. There are also other applications for this technology, including food safety, industrial process control, and environmental monitoring. The reduction in size and ease of use of these systems allows the devices to be deployed closer to the patient, where quick results facilitate better patient care management, thus lowering healthcare costs and minimizing inconvenience. In addition, this technology has potential applications in drug discovery, synthetic chemistry, and genetic research. [0008] Control of fluid movement within microfluidic channels is usually accomplished by the use of mechanical valves. An example of such a valve is taught in U.S. patent application Ser. No. 09/677,250, entitled “Valve for Use In Microfluidic Structures”, filed Oct. 2, 2000, and is assigned to the assignee of the present invention. This application describes a valve manufactured from a flexible material which allows one-way flow through microfluidic channels for directing fluids through a microfabricated analysis cartridge. This type of valve, however, is often difficult to fabricate due to its extremely small dimensions. [0009] It has also been proposed to use passive or nonmechanical means to control fluid movement in microfluidic channels. U.S. Pat. No. 6,193,471 is directed to a process and system for introducing menisci, arresting the movement of menisci at defined locations within the system, and for removing menisci from capillary volumes of a liquid sample, as well as delivering precise small volumes of liquid samples to a point of use. [0010] U.S. Pat. No. 6,130,098, which issued on Oct. 10, 2000, is directed to microscale devices using flow-directing means including a surface tension gradient mechanism in which discrete droplets are differentially heated and propelled through etched channels. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device. SUMMARY OF THE INVENTION [0011] It is therefore an object of the present invention to provide a passive valve within a microfluidic system which uses surface tension forces to control flow within the microfluidic channels. [0012] It is also an object of the present invention to provide a valve within a microfluidic channel such that the channel will open at a predetermined fluid pressure. [0013] These and other objects and advantages of the present invention will be readily apparent in the description that follows. BRIEF DESCRIPTION OF THE DRAWINGS [0014] [0014]FIG. 1 is an illustration of a microfluidic channel having sharp edges; [0015] [0015]FIG. 2 is an illustration of the channel of FIG. 1 containing a fluid having a meniscus extending beyond its edge; [0016] [0016]FIG. 3 is an illustration of a microfluidic channel having a plurality of branched channels; [0017] [0017]FIG. 4 is an illustration of a microfluidic channel having a central barrier within the channel; [0018] [0018]FIG. 5 is an illustration of a microfluidic channel having stepped branches; [0019] [0019]FIG. 6 is an illustration of an embodiment of a valve according to the present invention at intersecting microfluidic channels depicting a fluid in one channel; [0020] [0020]FIG. 7 shows the channels of FIG. 6 depicting fluids within both channels; and [0021] [0021]FIG. 8 is an illustration of a microfluidic channel having a soluble material deposited on its walls. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0022] Referring now to FIG. 1, there is shown a microfluidic channel 10 having an end 11 and containing a fluid 12 within its walls 14 , 16 . A concave meniscus 18 is formed at the leading edge of flowing fluid 12 within channel 10 . Edges 14 a, 16 a of channel walls 14 , 16 are formed at approximately 90° which constitute “sharp edges”, thus causing surface tension forces within flowing fluid 12 . As can be clearly seen in FIG. 2, fluid 12 moves within channel 10 due to a positive pressure upstream or a positive displacement. Its flow velocity is determined by several factors, including the magnitude of the pressure and the fluidic resistance of channel 10 . When fluid 12 reaches end 11 of channel 10 which contains sharp edges 14 a and 16 a, the fluidic resistance increases, and if the driving pressure is less than the force needed to overcome the surface tension resistance at edges 14 a, 16 a, the flow of fluid 12 will stop, and meniscus 18 will distend into the open space beyond edges 14 a, 16 a. [0023] The shape of the meniscus depends on several factors, such as properties of the material that composes the channel along with properties of the flowing fluid. For example, meniscus 18 may adopt a convex shape if the properties of the fluid and channel walls are conducive to the formation of that shape. Another factor which is related to this phenomenon is the angle of contact. If a liquid is in contact with a solid and with air along a line, the angle θ between the solid-liquid interface and the liquid-air interface is called the angle of contact. If θ=0, the liquid is said to wet the channel thoroughly. If θ is less than 90°, the liquid moves within the channel and forms a concave meniscus; and if more than 90°, the liquid does not wet the solid and is depressed within the channel, forming a convex meniscus. [0024] This phenomenon can also be used as a stream splitter when desirable. Referring now to FIG. 3, a main channel 30 contains a fluid 32 which flows toward a series of channel branches 34 , 36 , 38 at the distal end 40 of channel 30 . As fluid 32 flows toward end 40 , it will partition and flow at different velocities in each of channels 34 , 36 , 38 due to variation in the resistance within each channel. When fluid within fastest flowing channel 34 reaches a sharp edge boundary 34 a, flow will stop. Fluid in the second fastest flowing channel 36 will then reach a sharp edge boundary 36 and stop, while fluid within the slowest flowing channel 38 will finally reach a sharp edge boundary 38 a. The sizes and characteristics of channels 34 , 36 , 38 can be varied to control the speed of the flow in each channel. [0025] [0025]FIG. 4 shows another embodiment which uses branched fluidic channels to control fluid flow. A channel 41 divides into two arcuate paths 41 a, 41 b which converge at a channel 42 at a distance from channel 41 . A fluid traveling within channel 41 will divide and flow into channels 41 a, 41 b at different velocities until surface tension forces stop the flow and form menisci 43 a, 43 b at the junction of channels 41 a, 41 b and 42 . These junctions act as passive valves to control flow into channel 42 . The type of channel, materials, sizes, and fluid pressure all contribute to the forces necessary to overcome the surface tension which forms menisci 43 a, 43 b. [0026] [0026]FIG. 5 shows a further embodiment using branched fluidic channels for fluid control. A main channel 44 divides into two separate branch channels 44 a, 44 b. Channel 44 a is connected to a wider channel 45 , while channel 44 b is also connected to a wider channel 46 . Edges 45 a, 45 b of the junction of channels 44 a and 45 constitute “sharp edges” as discussed earlier while edges 46 a, 46 b of the junction of channels 44 b and 46 also contain sharp edges. [0027] As fluid flows within channel 44 and divides into channels 44 a and 44 b, the fluid will stop as it reaches edges 45 a, 45 b and 46 a, 46 b respectively, and if the driving pressure of the fluid is less than the force needed to overcome the surface tension at these edges, menisci 47 , 48 will form at the junction of the respective channels. Each channel can be constructed of the appropriate materials, or treated with hydrophobic or hydrophilic materials, to provide the proper surface tension resistance to the flow through channel 44 to achieve the desired flow timing from channels 44 a and 44 b. [0028] [0028]FIG. 6 shows an embodiment of microfluidic channels containing a passive valve using the principles of the present invention. Referring now to FIG. 6, a first microfluidic channel 50 is intersected by a second microfluidic channel 52 . The intersection of channels 50 , 52 is formed by a pair of sharp edges 54 , 56 which are offset such that channel 52 is separated into two channels 52 a and 52 b having different widths. [0029] A fluid stream 58 enters channel 50 via a port 60 and flows until it contacts sharp edges 54 , 56 at the intersection of channels 50 and 52 , where the flow stops due to surface tension. Stopped stream 58 forms a meniscus 62 which distends into channel 52 . To restart fluid flow within channel 50 , a fluid stream 64 is initiated in channel section 52 a in the direction indicated by arrow A, as can be seen in FIG. 7. As fluid stream 64 contacts meniscus 62 , the surface tension holding fluid stream 58 within channel 50 is overcome, thus reinitiating fluid flow from port 60 through channel 50 and into channel section 52 b. Although meniscus 62 is convex, this valve will operate if the meniscus is concave, as fluid stream 64 would contact the meniscus in channel 50 and reinitiate the flow. [0030] Surface tension valves may also be created in microfluidic channels by the use of hydrophobic or hydrophilic materials. For example, if a hydrophobic material is deposited in one or several spots within a channel, it would act like a valve in a microfluidic circuit for aqueous fluids. Referring now to FIG. 8, there is shown a microfluidic channel 80 having a pair of parallel walls 82 , 84 . A track 86 of material is deposited across the width of channel 80 . This material may be hydrophobic, such that an aqueous fluid flowing within channel 80 would stop when it reached material 86 if the fluid pressure within channel 80 was below the pressure level needed to overcome the surface tension at that point. Once the pressure exceeds the surface tension, the fluid will flow past material 86 , and once channel 80 is witted, the fluid would continue to flow. Material 86 can be added at several positions within channel 80 . [0031] It is also possible to deposit a soluble material in the microfluidic channel such that it will act as a valve until the flowing fluid is able to dissolve the material, thus permanently opening the passageway. This material can also be hydrophobic or hydrophilic and can present a certain definable initial resistance due to surface tension. [0032] While this invention has been shown and described in terms of a preferred embodiment, it will be understood that this invention is not limited to any particular embodiment and that changes and modifications may be made without departing from the true spirit and scope of the invention as defined in the appended claims.
A passive valve for use within microfluidic structures. Surface tension forces developed within microscale channels are used to control flow within the channels. Flow can be halted within a channel until fluid force reaches a predetermined pressure to allow the channel to open.
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BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to a speed reducer having a simple configuration, which is capable of precisely and reliably delivering the power to slow down. [0003] 2. Description of the Prior Art [0004] Generally, the speed reducer which has been conventionally widely used in related industries includes a pinion shaft that receives a power of the motor, a reduction gear that is integrally coupled to a one side of the pinion shaft, a ring gear meshing and rotating with the reduction gear, and a ring gear shaft for inducing the transmitted power to a drive shaft, the ring gear shaft having a pin hole in which a pin is inserted so as to fix the ring gear shaft into the ring gear. [0005] However, in the conventional speed reducer as described above, the output shaft of the speed reducer is coupled with the ring gear shaft by means of the pin so that the degree of coupling is not strong. Accordingly, it does not guarantee a smooth power transmission. Furthermore, when the speed reducer is operated for a long time, then the pin, the ring gear shaft and the output shaft, etc. cannot stand the rotational force and thereby resulting in frequent damage of these machine parts. As a result, it causes a failure of the reduction gear. [0006] In general, the ring gear is fixed on the ring gear shaft by means of a key. Likewise, these ring gear and the ring gear shaft may be easily and frequently damaged due to the rotation force while the speed reducer is operated for a long time. This leads to occurrence of excessive maintenance costs for the speed reducer. [0007] Meanwhile, since a rotational force may be transmitted through the output shaft of a one end of the driving shaft in the conventional speed reducer, the efficiency of power transfer is limited. [0008] Furthermore, in the conventional speed reducer, since the output shaft is not rigidly fixed, the fluctuations and the uneven wear of the output shaft was terribly occurred, and thereby resulting in the limitation of the transfer of minute rotational force. Since most of the mechanical constitution is very complicate and the overall volume is large, it is hard to use in a system that requires a precise control such as joints of the robot and this leads to occurrence of excessive manufacturing costs. SUMMARY OF THE INVENTION [0009] In consideration of the above-mentioned disadvantages or inconveniences of the conventional techniques, an object of the present invention is to provide a speed reducer having a simple configuration, which is capable of precisely and reliably delivering the power to slow down, and which can be miniaturized and can operate stably without fluctuation. [0010] Other object of the present invention is to provide a speed reducer can be widely applied because it can employ various gears such as a planet gear, a spur gear and a harmonic gear, etc. as the reduction gear for decelerating a rotational speed. [0011] In order to achieve the objects, the present invention provides a speed reducer comprising: [0012] a driving gear being installed at a one end of a driving shaft driven by a driving means; [0013] a driven gear for changing the direction of the rotational force of the driving gear, the driven gear being meshed with the driving gear; and [0014] a rotational member for outputting the rotational force to slow down, the rotational member being coupled to the driven gear. [0015] Preferably, the driving gear comprises a first driving gear and a second driving gear, which are positioned facing each other with making a pair and are different from each other in size, and wherein the driven gear comprises a first driven gear and a second driven gear, which are positioned facing each other with making a pair, in which the first driven gear and the second driven gear are meshed with the first driving gear and the second driving gear, respectively. [0016] The first driving gear and the second driving gear are installed at a driving shaft with facing each other. Likewise, the first driven gear and the second driven gear are installed at a driven shaft with facing each other. The driven gears are meshed with the driving gear, respectively so that they output a driving force to the outside. [0017] Especially, since the first driving gear and the first driven gear have a different size with the same gear ratio, and similarly the second driving gear and the second driven gear have a different size with the same gear ratio, the first driven gear and the second driven gear rotate by the same revolutions. [0018] If the drive gears and the driven gears are configured to have different sizes as described above, they can be installed at one driving shaft so that they can be coupled to the driven shaft, respectively without interference with each other. As a result, it is possible to minimize the total size of the reduction gear and thereby resulting in manufacturing of the precision reduction gear. Since the driving force can be outputted from both sides of the driving shaft and it is transferred to one rotational member, the speed reducer can precisely and reliably deliver the power in a state that it may operate stably without fluctuation. [0019] Preferably, the driving gears and the driven gears comprise a bevel gear, respectively. Alternatively, the driving gears and the driven gears comprise a worm screw and a worm wheel, respectively. Any gear system which is capable of changing the direction of the rotational force of the driving gear into a direction perpendicular to the original direction may be employed. [0020] The driven gear is supported by a driven shaft which comprises a non-rotating fixed shaft, and the driving shaft being installed at the driven shaft in a manner that it passes through a middle portion of the driven shaft. Since the driving gear rotates with the driving shaft as a unit and the driven shaft supports the driven gear, the driven gear may be idling-rotated on the driven shaft. Thus, although the driving shaft and the driven shaft intersect with each other, they do not give any hindrance in each of the power transmission. [0021] Furthermore, in order to achieve the objects, the present invention provides a speed reducer comprising: [0022] a driving shaft driven by a driving means; [0023] a pair of driving gears comprising a first driving gear and a second driving gear, in which the first driving gear and the second driving gear are installed at a one end of the driving shaft and are positioned facing each other, and the first driving gear and the second driving gear have a different size with the same gear ratio and comprise a bevel gear, respectively; [0024] driven gears comprising a first driven gear and a second driven gear, which are positioned facing each other with making a pair, in which the first driven gear and the second driven gear are meshed with the first driving gear and the second driving gear, respectively and they comprise a bevel gear, respectively; [0025] a driven shaft for supporting the first driven gear and the second driven gear, in which the driving shaft is installed at the driven shaft in a manner that it passes through a middle portion of the driven shaft; and [0026] a rotational member for outputting the rotational force to slow down, the rotational member being coupled to the driven gear. [0027] An idle gear for supporting the other end of the driven gear is installed at the driving shaft and is positioned facing to the driving gear, in which the idle gear and the driving gear have a same size with the same gear ratio. [0028] Preferably, the speed reducer further comprises an auxiliary speed reducing means installed at the outside of the driven gear. [0029] The auxiliary speed reducing means comprises a sun gear installed at the driven gear, a planetary gear meshed with the sun gear, and a ring gear meshed with the planetary gear. Alternatively, the auxiliary speed reducing means comprises a combination of spur gears. Alternatively, the auxiliary speed reducing means comprises a harmonic gear. Any rotational force transmitted from the driving shaft may be outputted to slow down due to the operation of the auxiliary speed reducing means. The rotational member for outputting the driving force to slow down can be designed various types in accordance with applications. Preferably, the rotational member may be installed to the driven gear in a manner that it can rotate against the driven gear at 360 degrees. Alternatively, the rotational member is eccentrically mounted to the driven shaft in a manner that it can eccentrically rotate against the driven shaft in an eccentric state. [0030] As described above, the speed reducer according to the present invention can precisely and reliably deliver the power to slow down and can operate stably without fluctuation by employing the gear system which is capable of changing the direction of the rotational force into a direction perpendicular to the original direction. [0031] Since the speed reducer according to the present invention can employ various gears such as a planet gear, a spur gear and a harmonic gear, etc. as the reduction gear for decelerating a rotational speed, it can be widely applied. [0032] Furthermore, the speed reducer according to the present invention can minimize the total size of the reduction gear, thereby resulting in the reduction of the manufacturing cost. Furthermore, the speed reducer according to the present invention can be applied in various fields that require miniaturization and refinement. BRIEF DESCRIPTION OF THE DRAWINGS [0033] The above objects and other characteristics and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings, in which: [0034] FIG. 1 is an exterior perspective view of a speed reducer according to a preferred first embodiment of the present invention; [0035] FIG. 2 is an exploded perspective view of the speed reducer as illustrated in FIG. 1 ; [0036] FIG. 3 shows an external appearance of the speed reducer as illustrated in FIG. 1 ; [0037] FIG. 4 shows an application state that the speed reducer as illustrated in FIG. 1 is installed at a robot joint; [0038] FIG. 5 is a partial side sectional view of the speed reducer and the robot joint as illustrated in FIG. 4 ; [0039] FIG. 6 is an exterior perspective view of the speed reducer according to the preferred first embodiment of the present invention, for showing a state that a fluctuation prevention means is installed at the speed reducer; [0040] FIG. 7 is a sectional view of the robot joint employing the speed reducer as illustrated in FIG. 6 ; [0041] FIG. 8 is a partial side sectional view of the speed reducer and the robot joint as illustrated in FIG. 7 ; [0042] FIG. 9 is an exploded perspective view of a speed reducer according to another exemplarily embodiment of the present invention, [0043] FIG. 10 is an exterior perspective view of a speed reducer according to a preferred second embodiment of the present invention; [0044] FIG. 11 is an exploded perspective view of the speed reducer as illustrated in FIG. 10 ; [0045] FIG. 12 is a partial side sectional view of the speed reducer and the robot joint, for showing an application state that the speed reducer as illustrated in FIG. 10 is installed at the robot joint; [0046] FIG. 13 is an exterior perspective view of the speed reducer according to the preferred second embodiment of the present invention, for showing a state that a fluctuation prevention means is installed at the speed reducer; [0047] FIG. 14 is an exploded perspective view of the speed reducer and the robot joint, for showing the application state that the speed reducer as illustrated in FIG. 12 is installed at the robot joint; [0048] FIG. 15 is an exterior perspective view of a speed reducer according to a preferred third embodiment of the present invention; [0049] FIG. 16 is an exterior perspective view of the speed reducer according to the preferred third embodiment of the present invention, for showing a state that a fluctuation prevention means is installed at the speed reducer; [0050] FIG. 17 shows an external appearance of the speed reducer according to the preferred third embodiment of the present invention; [0051] FIG. 18 is an exterior perspective view of the speed reducer and the robot joint, for showing the application state that the speed reducer according to the preferred third embodiment of the present invention is installed at the robot joint; [0052] FIG. 19 is an exterior perspective view of a speed reducer according to a preferred fourth embodiment of the present invention; [0053] FIG. 20 is an exploded perspective view of the speed reducer as illustrated in FIG. 19 ; [0054] FIG. 21 is an exterior perspective view of the speed reducer according to the preferred fourth embodiment of the present invention, for showing a state that a fluctuation prevention means is installed at the speed reducer; [0055] FIG. 22 shows an application state that the speed reducer as illustrated in FIG. 21 is installed at a robot joint; and [0056] FIG. 23 is an exterior perspective view of the speed reducer and the robot joint, for showing the application state that the speed reducer according to the preferred fourth embodiment of the present invention is installed at the robot joint. DETAILED DESCRIPTION OF THE INVENTION [0057] Hereinafter, the constitution of the abalone habitat reef according to the present invention will be explained in more detail with reference to the accompanying drawings. [0058] Prior to proceeding to the more detailed description of the preferred embodiments according to the present invention, it should be noted that, for the sake of clarity and understanding of the invention identical components which have identical functions have been identified with identical reference numerals throughout the different views which are illustrated in each of the attached drawing Figures. [0059] FIG. 1 is an exterior perspective view of a speed reducer according to a preferred first embodiment of the present invention, FIG. 2 is an exploded perspective view of the speed reducer as illustrated in FIG. 1 , FIG. 3 shows an external appearance of the speed reducer as illustrated in FIG. 1 , and FIG. 4 shows an application state that the speed reducer as illustrated in FIG. 1 is installed at a robot joint. [0060] Referring to FIGS. 1 to 4 , the speed reducer comprises a driving gear installed at a one end of a driving shaft 10 which rotates by receiving a driving force from a driving means such as a motor, an engine, etc. The speed reducer further comprises a driven gear for changing the direction of the rotational force of the driving gear into a direction perpendicular to the original direction. The driven gear is installed to the driving gear. As shown in the attached drawings FIG. 1 to FIG. 4 , the driving gear and the driven gear comprises a bevel gear. [0061] The driving gear includes a first driving gear 11 and the second driving gear 12 , which are positioned on the driving shaft 10 facing each other with making a pair and are different from each other in size, and they have the same gear ratio. [0062] The driven gear comprises a first driven gear 21 and a second driven gear 22 , which are positioned on a driven shaft 20 facing each other with making a pair. The first driven gear 21 and the second driven gear 22 are meshed with the first driving gear 10 and the second driving gear 12 , respectively. The first driven gear 21 and the second driven gear 22 are installed on the driven shaft 20 in a manner that they are arranged in a direction perpendicular to the driving shaft 10 . Accordingly, the direction of the driven shaft 20 is perpendicular to the direction of the driving shaft 10 . [0063] The driven shaft 20 comprises a non-rotating fixed shaft. The first driven gear 21 and the second driven gear 22 are installed on the driven shaft 20 in a manner that they can rotate about the driven shaft 20 . Since the driving shaft 10 passes through a middle portion of the driven shaft 20 , it is possible to reduce the total volume of the speed reducer. [0064] Like the structure of the first driving gear 11 and the second driving gear 12 , the first driven gear 21 and the second driven gear 22 have a different size and a same gear ratio. The first driven gear 21 is meshed with the first driving gear 11 and the second driven gear 22 is meshed with the second driving gear 12 , respectively. Due to this gear system, the rotational force of the driving shaft 10 can be transmitted in the direction perpendicular to the direction of the driving shaft 10 . [0065] The speed reducer as described above can be designed as a speed reducer 100 which may be embedded in a case 101 as best shown in FIG. 3 . The driving shaft 10 outwardly extends from a one surface of the speed reducer 100 so that it may be connected with a driving means. Side surfaces of the first driven gear 21 and the second driven gear 22 or a member for transmitting the rotational force of the driving shaft 10 may be mounted to both sides of the speed reducer 100 . As shown in FIG. 4 , a rotational member 200 to be rotated can be mounted to the connecting member or the surfaces of the first driven gear 21 and the second driven gear 22 . [0066] FIG. 5 is a partial side sectional view of the speed reducer and the robot joint as illustrated in FIG. 4 . As shown in FIG. 5 , a pair of connecting members 201 extending from an end of the rotational member 200 can be connected with outer portions of the driven gear. [0067] Hereinafter, the operation of the speed reducer according to the first embodiment of the present invention will be simply explained. [0068] If the driving shaft 10 rotates by receiving a driving power from a driving means, the first driving gear 11 and the second driving gear 12 installed on the same driving shaft also rotate. Continuously, the first driven gear 21 meshed with the first driving gear 11 and the second driven gear 22 meshed with the second driving gear 12 rotate, respectively. Since the driving gears 11 , 12 rotate in a state that they contact with an outer circumferential surface of the driven gears 21 , 22 , respectively, the driven gears 21 , 22 have the same rotational direction with each other. [0069] Since the connecting member 201 connected to the driven gears may output the same movement, the rotational member 200 can rotate by receiving a stable rotational force outputted from both side surfaces of the speed reducer 100 . [0070] Meanwhile, FIG. 6 is an exterior perspective view of the speed reducer according to the preferred first embodiment of the present invention, for showing a state that a fluctuation prevention means is installed at the speed reducer, FIG. 7 is a sectional view of the robot joint employing the speed reducer as illustrated in FIG. 6 , and FIG. 8 is a partial side sectional view of the speed reducer and the robot joint as illustrated in FIG. 7 . [0071] In the first embodiment according to the present invention, since the driving gears 11 , 12 rotate in a state that they contact with an outer circumferential surface of the driven gears 21 , 22 , respectively, a stress to be biased to one side may be generated. This leads the generation of fine tremor or vibration in the speed reducer. Accordingly, it is required to employ to a means for preventing the generation of fine tremor or vibration. [0072] In order to solve this problem, an idle gear that is a fluctuation prevention means is further installed at the driving shaft 10 so as to transmit a driving power more reliable. [0073] The idle gear comprises a first idle gear 31 and a second idle gear 32 . The first idle gear 31 has the same size as the first driving gear 11 and it has the same gear ratio as the first driving gear 11 . The first idle gear 31 is meshed with an outer circumferential surface of the first driven gear 21 so as to support the first driven gear 21 in a manner that it is opposite to the first driving gear 11 on the driving shaft 10 . Likewise, the second idle gear 32 has the same size as the second driving gear 12 and it has the same gear ratio as the second driving gear 12 . The second idle gear 32 is meshed with an outer circumferential surface of the second driven gear 22 so as to support the second driven gear 22 in a manner that it is opposite to the second driving gear 12 on the driving shaft 10 . [0074] The first idle gear 31 and the second idle gear 32 idling on the driving shaft 10 so that they support the driven gears 21 , 22 , respectively. As a result, the driven gears 21 , 22 can be supported at both sides of the driven shaft 20 and can transmit the driving power at the same gear ratio. Consequently, this gear system can transfer more precise rotation. [0075] In the first embodiment according to the present invention, as described above, the driving gears are installed on the driving shaft in a state that they are opposite with each other and driven gears being meshed with these driving gears are installed on the driven shaft in a state that they are opposite with each other. Due to this structure, there is no interference between the first driving gear 11 and the second driven gear 22 , or between the second driving gear 12 and the first driven gear 21 . This leads to the smooth power transmission of the gear system. Also, it is possible to reduce the total volume of the speed reducer and it can make more precise speed reducer. [0076] Although the driving gears and the driven gears comprise a bevel gear so as to output the rotational force in a direction perpendicular to the original direction, most of the gear which is capable of changing the direction of power transmission may be employed. For example, FIG. 9 is an exploded perspective view of a speed reducer according to another exemplarily embodiment of the present invention, for showing the driving gear and the driven gear comprise a worm screw and a worm wheel, respectively. [0077] FIGS. 10 to 14 show the speed reducer according to a preferred second embodiment of the present invention. FIG. 10 is an exterior perspective view of the speed reducer, FIG. 11 is an exploded perspective view of the speed reducer as illustrated in FIG. 10 , and FIG. 12 is a partial side sectional view of the speed reducer and the robot joint. [0078] Referring to FIGS. 10 to 12 , the speed reducer according to the preferred second embodiment of the present invention has the same configuration as that of the first embodiment. In other words, the speed reducer according to the preferred second embodiment of the present invention comprises the first driving gear 11 and the second driving gear 12 which comprise a bevel gear, respectively and are installed on the driving shaft 10 in a state that they are opposite to each other; the first driven gear 21 and the driven gear 22 which are installed on the driven shaft in a state that they are opposite to each other and they can be meshed with the first driving gear 11 and the second driving gear 12 ; and the driven shaft 20 for supporting the first driven gear 21 and the driven gear 22 . The speed reducer according to the preferred second embodiment of the present invention further comprises an auxiliary speed reducing means for transmitting the slowed rotational force to further slow down. [0079] The auxiliary speed reducing means comprises a sun gear 51 installed at the driven gear, a planetary gear 52 meshed with the sun gear 51 , and a ring gear 53 meshed with the planetary gear 52 . The sun gear 51 is installed on the driven shaft 20 in a state that it can rotate at outer side surface of the driven gears 21 , 22 as a unit. [0080] The ring gear 53 may be directly installed in the case 101 of the speed reducer 100 as shown in the drawings. A gear shaft of the planetary gear 52 is assembled and fixed to the connecting member 201 of the rotational member 200 to be coupled to the speed reducer 100 . [0081] Due to this structure, the rotational force of the first driving gear 11 and the second driving gear 12 provided by the driving shaft 10 can be transmitted to the first driven gear 21 and the second driven gear 22 to slow down, in turns, after decelerating it again by means of the auxiliary speed reducing means, it can be transmitted to the rotational member 200 coupled to the gear shaft 54 of the planetary gear 52 . [0082] FIGS. 13 and 14 show a state that a fluctuation prevention means is installed at the speed reducer as in the first embodiment according to the present invention. As shown in FIGS. 13 and 14 , the first idle gear 31 and the second idle gear 32 for supporting the first driven gear 21 and the second driven gear 22 are installed on the driving shaft 10 . [0083] FIGS. 15 to 18 show the speed reducer according to a preferred third embodiment of the present invention. FIG. 15 is an exterior perspective view of the speed reducer, FIG. 16 is an exterior perspective view of the speed reducer, for showing a state that a fluctuation prevention means is installed at the speed reducer, FIG. 17 shows an external appearance of the speed reducer installed within a case, and FIG. 18 is an exterior perspective view of the speed reducer and the robot joint, for showing the application state that the speed reducer is installed at the robot joint. [0084] Referring to FIGS. 15 to 18 , the speed reducer according to the preferred third embodiment of the present invention has the same configuration as that of the first embodiment. [0085] In other words, the speed reducer according to the preferred third embodiment of the present invention comprises the first driving gear 11 and the second driving gear 12 which comprise a bevel gear, respectively and are installed on the driving shaft 10 in a state that they are opposite to each other; the first driven gear 21 and the driven gear 22 which are installed on the driven shaft in a state that they are opposite to each other and they can be meshed with the first driving gear 11 and the second driving gear 12 ; and the driven shaft 20 for supporting the first driven gear 21 and the driven gear 22 . The speed reducer according to the preferred third embodiment of the present invention further comprises an auxiliary speed reducing means for transmitting the slowed rotational force to further slow down. [0086] The auxiliary speed reducing means comprises an output gear 61 installed on the driven shaft 20 in a manner that it may integrally formed or fixed with an outer side surface of the driven gears 21 , 22 as a unit, and a spur gear 62 meshed with the output gear 61 . [0087] Due to this structure, the rotational force of the first driving gear 11 and the second driving gear 12 provided by the driving shaft 10 can be transmitted to the first driven gear 21 and the second driven gear 22 to slow down, in turns, after decelerating it again by means of the spur gear 62 , it can be transmitted to the rotational member 200 . Appropriate number of spur gears can be added between the output gear 61 and the spur gear 62 according to the need. Furthermore, as shown in FIG. 16 , it is possible to additionally install the first idle gear 31 and the second idle gear 32 can be installed on the driving shaft 10 so as to prevent fluctuation during the power transmission. [0088] FIG. 19 is an exterior perspective view of a speed reducer according to a preferred fourth embodiment of the present invention, FIG. 20 is an exploded perspective view of the speed reducer as illustrated in FIG. 19 , FIG. 21 is an exterior perspective view of the speed reducer, for showing a state that a fluctuation prevention means is installed at the speed reducer, FIG. 22 shows an application state that the speed reducer as illustrated in FIG. 21 is installed at a robot joint, and FIG. 23 is an exterior perspective view of the speed reducer and the robot joint, for showing the application state that the speed reducer according to the preferred fourth embodiment of the present invention is installed at the robot joint. [0089] Referring to FIGS. 19 to 23 , the speed reducer according to the preferred fourth embodiment of the present invention has the same configuration as that of the first embodiment. [0090] In other words, the speed reducer according to the preferred fourth embodiment of the present invention comprises the first driving gear 11 and the second driving gear 12 which comprise a bevel gear, respectively and are installed on the driving shaft 10 in a state that they are opposite to each other; the first driven gear 21 and the driven gear 22 which are installed on the driven shaft in a state that they are opposite to each other and they can be meshed with the first driving gear 11 and the second driving gear 12 ; and the driven shaft 20 for supporting the first driven gear 21 and the driven gear 22 . The speed reducer according to the preferred third embodiment of the present invention further comprises an auxiliary speed reducing means for transmitting the slowed rotational force to further slow down. [0091] The auxiliary speed reducing means comprises a harmonic gear installed on the driven shaft 20 in a manner that it may integrally formed or fixed with an outer side surface of the driven gears 21 , 22 as a unit. An internal gear 71 that is a part of the harmonic gear 70 may be directly formed at an inner side of the case 101 . [0092] Due to this structure, the rotational force of the first driving gear 11 and the second driving gear 12 provided by the driving shaft 10 can be transmitted to the first driven gear 21 and the second driven gear 22 to slow down, in turns, after decelerating it again by means of the harmonic gear 70 , it can be transmitted to the rotational member 200 . [0093] Furthermore, as shown in FIGS. 21 and 22 , it is possible to additionally install the first idle gear 31 and the second idle gear 32 can be installed on the driving shaft 10 so as to prevent fluctuation during the power transmission. [0094] As described above, the speed reducer according to the present invention can be applied to various instruments. For example, if the reduction gear and the rotational member are used in the joint of robot, the rotational member functions as the robot arm. [0095] When the driving gear and the driven gear are installed on the driving shaft and the driven shaft with making a pair, they can have a different gear ratio so as to allow them to rotate at a different rotational speed. [0096] When the driven gears are installed on the driven shaft with making a pair, one rotational member can be connected to outer side surfaces of the driven gears. Alternatively, different rotational members can be connected to the individual driven gear. Alternatively, different rotational members can be installed in a manner that they can rotate at a different rotational speed. The rotational member is installed to the driven gear in a manner that it can rotate against the driven gear at 360 degrees. Alternatively, the rotational member is eccentrically mounted to the driven shaft in a manner that it can eccentrically rotate against the driven shaft in an eccentric state. [0097] It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the above description or illustrated in the drawings. [0098] The invention is capable of other embodiments and of being practiced and carried out in various ways by modifying the structure of artificial reef as needs of manufacturer of the artificial reef on the basis of its application. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. [0099] 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.
Disclosed is a speed reducer capable of precisely and reliably maintaining a rotational force of the output shaft and of maximizing its efficiency by allowing the rotational force of the driving shaft to transmit and to slow down via a plurality of bevel gears and by preventing the fluctuation of the output shaft so as to prevent uneven wear due to the long working and to prevent the damage due to the fluctuation. The speed reducer comprises a pair of driving gears 11,12 installed at a one end of a driving shaft 10 driven by a driving means, a pair of driven gears 21,22 meshed with the driving gear 11,21 and a rotational member 200 for outputting the rotational force to slow down, in which the driven gears 21,22 comprise a bevel gear, respectively and the rotational member 200 is coupled to the driven gears 21,22.
5
BACKGROUND OF THE INVENTION [0001] This disclosure relates to an electrochemical method and apparatus, more particularly, relates to an oxidation and reduction process and even more particularly, relates to an improved system and process for producing chlorine dioxide. [0002] With the decline of gaseous chlorine as a microbiocide and bleaching agent, various alternatives have been explored, including bleach, bleach with bromide, bromo-chlorodimethyl hydantoin, ozone, and chlorine dioxide (ClO 2 ). Of these, chlorine dioxide has generated a great deal of interest for control of microbiological growth in a number of different industries, including the dairy industry, the food and beverage industry, the pulp and paper industries, the fruit and vegetable processing industries, various canning plants, the poultry industry, the beef processing industry and miscellaneous other food processing applications. Chlorine dioxide is also seeing increased use in municipal potable water treatment facilities, potable water pathogen control in office building and healthcare facilities, industrial cooling loops, and in industrial waste treatment facilities, because of its selectivity towards specific environmentally-objectionable waste materials, including phenols, sulfides, cyanides, thiosulfates, and mercaptans. In addition, chlorine dioxide is being used in the oil and gas industry for downhole applications as a well stimulation enhancement additive. [0003] Unlike chlorine, chlorine dioxide remains a gas when dissolved in aqueous solutions and does not ionize to form weak acids. This property is at least partly responsible for the biocidal effectiveness of chlorine dioxide over a wide pH range, and makes it a logical choice for systems that operate at alkaline pHs or that have poor pH control. Moreover, chlorine dioxide is a highly effective microbiocide at concentrations as low as 0.1 parts per million (ppm) over a wide pH range. [0004] The biocidal activity of chlorine dioxide is believed to be due to its ability to penetrate bacterial cell walls and react with essential amino acids within the cell cytoplasm to disrupt cell metabolism. This mechanism is more efficient than other oxidizers that “burn” on contact and is highly effective against legionella, algae and amoebal cysts, giardia cysts, coliforms, salmonella, shigella, and cryptosporidium. [0005] Unfortunately, chlorine dioxide can become unstable and hazardous under certain temperature and pressure conditions. Although this is only an issue of concern for solutions of relatively high concentration, its shipment, at any concentration, is banned. It is for this reason that chlorine dioxide is always generated on-site, at the point of use, usually from a metal chlorate or metal chlorite as an aqueous solution. For example, a metal chlorite solution mixed with a strong acid can be used to generate chlorine dioxide in situ. [0006] Electrochemical processes provide a means for generating chlorine dioxide for point of use applications. For example, U.S. Pat. No. 5,419,816 to Sampson et al. describes a packed bed ion exchange electrolytic system and process for oxidizing species in dilute aqueous solutions by passing the species through an electrolytic reactor packed with a monobed of modified cation exchange material. A similar electrolytic process is described in U.S. Pat. No. 5,609,742 to Sampson et al. for reducing species using a monobed of modified anion exchange. [0007] One difficulty with electrochemical processes is that it can be difficult to control the generation of undesirable species. For example, there are many electrochemical reactions that can occur at the anode. Within a potential range of 0.90 to 2.10 volts, at least eight different reactions are thermodynamically possible, producing products such as chlorate (ClO 3 − ), perchlorate (ClO 4 − ), chlorous acid (HClO 2 ), oxygen (O 2 ), hydrogen peroxide (H 2 O 2 ) and ozone (O 3 ). It is highly desirable and a significant commercial advantage for an apparatus to allow for careful control of the products generated to achieve high yield efficiency. [0008] Chlorine dioxide has also been produced from a chlorine dioxide precursor solution by contacting the precursor solution with a catalyst (e.g., catalysts containing a metal such as those catalysts described for example in U.S. Pat. No. 5,008,096) in the absence of an electrical field or electrochemical cell. However, known catalytic processes have the disadvantage of becoming greatly deactivated within a matter of days. Moreover, it has been found that the support materials for the catalytic sites tend to quickly degrade due to the oxidizing nature of chlorine dioxide. Still further, the use of catalyst materials in packed columns or beds for generating chlorine dioxide has been found to cause a significant pressure drop across the column or form channels within the column that results in a significant decrease in conversion efficiency from the chlorine dioxide precursor to chlorine dioxide. It is also noted that catalyst materials are relatively expensive and can add significant cost to an apparatus employing these materials. SUMMARY OF THE INVENTION [0009] Disclosed herein is a system and apparatus for producing a halogen oxide such as chlorine dioxide. The system comprises an electrolytic reactor comprising a compartment having an inlet and an outlet, an anode, a cathode, and a particulate material disposed between the cathode and the anode, wherein the particulate material comprises a cation exchange material; a source of direct current in electrical communication with the anode and the cathode; and a fixed bed reactor comprising a chamber having an inlet and an outlet, wherein the fixed bed reactor chamber contains a redox exchanger material, and wherein the fixed bed reactor inlet is in fluid communication with the electrolytic reactor outlet. [0010] A process for producing halogen oxide comprises feeding an aqueous alkali metal halite solution into an electrolytic reactor to produce an effluent containing halous acid; feeding the halous acid containing effluent into a fixed bed reactor containing a redox exchanger material; and contacting the halous acid containing effluent with the redox exchanger material to produce a halogen oxide. [0011] In another embodiment, a process for producing for producing chlorine dioxide from an alkali metal chlorite solution comprises applying a current to an electrolytic reactor, wherein the electrolytic reactor includes an anode compartment comprising an anode, a cathode compartment comprising a cathode, and a central compartment positioned between the anode and cathode compartments, wherein the central compartment comprises a cation exchange material and is separated from the cathode compartment with a cation exchange membrane; feeding the alkali metal chlorite solution to the central compartment; electrolyzing water in the anode compartment to produce an oxygen containing effluent; exchanging the alkali metal ions with hydrogen ions to produce a chlorous acid containing effluent from the central compartment; combining the chlorous acid effluent with the oxygen containing effluent and feeding the combined effluents to the fixed bed reactor; and oxidizing the chlorous acid with a redox exchanger material in the fixed bed reactor to produce chlorine dioxide and regenerating the redox exchanger material. [0012] In another embodiment, a process for producing chlorine dioxide from an alkali metal chlorite solution comprises applying a current to an electrolytic reactor, wherein the electrolytic reactor includes an anode compartment comprising an anode, a cathode compartment comprising a cathode, and a central compartment positioned between the anode and cathode compartments, wherein the central compartment comprises a cation exchange material and is separated from the cathode compartment with a cation exchange membrane; flowing a solution comprising water in the anode compartment to produce an oxygen containing effluent; diluting an alkali metal chlorite solution with the oxygen containing effluent; feeding the diluted alkali metal chlorite solution to the central compartment; exchanging the alkali metal ions with hydrogen ions to produce a chlorous acid and oxygen containing effluent in the central compartment; feeding the effluent to a fixed bed reactor containing a redox exchanger material; and contacting the effluent with the redox exchanger material in the fixed bed reactor to produce chlorine dioxide and continuously regenerate the redox exchanger material. [0013] In another embodiment, a process for regenerating a fixed bed reactor containing a redox exchanger material comprises electrolyzing water in an electrolytic reactor to produce an oxygen containing effluent; and flowing the oxygen containing effluent into the fixed bed reactor to regenerate the redox exchanger material. [0014] The above-described embodiments and other features will become better understood from the detailed description that is described in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0015] Referring now to the figures wherein the like elements are numbered alike: [0016] FIG. 1 shows a cross sectional view illustrating a system comprising an electrolytic reactor and a fixed bed reactor; [0017] FIG. 2 shows a cross sectional view illustrating the a single compartment electrolytic reactor; [0018] FIG. 3 shows a cross sectional view illustrating a two-compartment electrolytic reactor; [0019] FIG. 4 shows a cross sectional view illustrating an multi-compartment electrolytic reactor; [0020] FIGS. 5A and 5B show an exploded isometric view of an electrolytic reactor cassette employing the multi-compartment reactor of FIG. 4 ; [0021] FIG. 6 is a graph showing chlorine dioxide conversion efficiency from an alkali metal chlorite feed solution in the system as shown in FIG. 1 employing a manganese greensand redox exchange media in the fixed bed reactor; [0022] FIG. 7 is a graph showing chlorine dioxide conversion efficiency from an alkali metal chlorite feed solution in the system as shown in FIG. 1 employing PYROLOX® redox exchange media in the fixed bed reactor; [0023] FIG. 8 is a graph showing chlorine dioxide conversion efficiency from an alkali metal chlorite feed solution in the system as shown in FIG. 1 employing BIRM® redox exchange media in the fixed bed reactor; and [0024] FIG. 9 is a graph showing chlorine dioxide conversion efficiency from an alkali metal chlorite feed solution in a system employing a three-compartment electrolytic reactor and a fixed bed reactor containing manganese greensand redox exchange media, wherein an oxidizing agent generated in the anode compartment is not introduced into the fixed bed reactor or the central compartment of the reactor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0025] A system and process for producing halogen oxide from alkali metal halite solutions are disclosed, such as, for example, producing chlorine dioxide from an alkali metal chlorite solution. The system and process generally include employing an electrolytic reactor for producing an aqueous effluent containing halous acid and oxygen, which is then fed to a fixed bed reactor containing a redox exchanger material for converting the halous acid to halogen oxide. In a preferred embodiment, the alkali metal halite is an alkali metal chlorite for producing chlorine dioxide. Advantageously, the system provides an economical alternative to other types of systems that utilize expensive catalyst materials. For example, most redox exchanger materials are commercially available at costs of about 35 to about 200 times less than the cost of the precious metal-supported catalyst materials. [0026] In a more preferred embodiment, the alkali metal chlorite solutions are dilute solutions. The term “dilute” refers to aqueous alkali metal chlorite solutions containing less than about 10,000 milligrams alkali metal chlorite per liter of solution (mg/L), preferably less than about 5,000 mg/L, and more preferably less than about 1,500 mg/L. For industrial use, the alkali metal chlorite solution is preferably in the form of a 25% aqueous solution in view of handling property, safety and the like, which can be further diluted during use. Suitable alkali metals include sodium, potassium, lithium, and the like, with preference given to sodium salt considering the commercial availability. [0027] Referring now to FIG. 1 , wherein like elements are numbered alike, there is shown a cross-sectional view illustrating a system 10 that generally comprises an electrolytic reactor 20 including an inlet 22 and an outlet 24 , wherein the outlet 24 is in fluid communication with an inlet 26 of a fixed bed reactor 200 . As will be discussed in greater detail, the system 10 can be utilized for continuously generating an aqueous effluent containing chlorine dioxide from an outlet 28 of the fixed bed reactor 200 . For example, an alkali metal chlorite solution can be fed into the inlet of the electrolytic reactor 20 to generate an aqueous effluent containing chlorous acid. The chlorous acid effluent is then fed to inlet 26 of the fixed bed reactor 200 , wherein the chlorous acid is oxidized to form chlorine dioxide. An oxidizing agent generated during electrolysis in the electrolytic reactor 20 is additionally directed to the fixed bed reactor 100 , individually or in combination with the chlorous acid, to continuously or periodically regenerate the fixed bed reactor 200 . In this manner, it has been found that high conversion efficiencies of chlorite ions to chlorine dioxide as well as continuous production can be achieved economically. [0028] Suitable electrolytic reactors 20 for use in system 10 include a single compartment reactor 30 as shown in FIG. 2 , a two-compartment reactor 50 as shown in FIG. 3 , or a multi-compartment reactor, i.e., a reactor containing three or more compartments. An exemplary multi-compartment electrolytic reactor 70 configured with three compartments is shown in FIG. 4 . [0029] Referring now to FIG. 2 , the single compartment electrolytic reactor 30 includes an anode 32 and a cathode 34 in electrical communication with a source of direct current 36 (DC). Interposed between the anode 32 and the cathode 34 exists at least one compartment 38 containing particulate material 40 . Compartment 38 further includes an inlet 42 for introducing an alkali metal chlorite feed solution to the electrolytic reactor 30 and an outlet 44 for discharging an effluent from the electrolytic reactor 30 . [0030] As used herein, the term “particulate material” refers to a cation exchange material and/or an anion exchange material. Any cation exchange material can be used provided portions of its active sites are occupied with hydrogen, i.e., cation exchange material in the hydrogen form. In a preferred embodiment, the particulate material 40 in compartment 38 includes the cation exchange material or a mixture of the cation exchange material and the anion exchange material. In the case of mixtures of the cation and anion exchange materials, the majority of the particulate material 40 within compartment 38 is preferably the cation exchange material. The particulate material 40 may also include an additive or additives to achieve certain results. For example, electrically conductive particles, such as carbon and the like, can be used to affect the transfer of DC current across electrodes. However, some additives, such as carbon, are prone to disintegration in acidic environments, thus requiring careful selection. [0031] As shown in FIG. 3 , the two-compartment electrolytic reactor 50 includes an anode 32 , an anode compartment 52 , a cathode 34 , and a cathode compartment 54 , wherein the anode 32 and cathode 34 are in electrical communication with a source of direct current 36 (DC). A membrane 56 preferably separates the anode compartment 52 from the cathode compartment 54 . The anode compartment 52 further includes inlet 58 and outlet 60 . Similarly, the cathode compartment 54 includes inlet 62 and outlet 64 . [0032] As used herein, the term “membrane” generally refers to a sheet for separating adjacent compartments, e.g., compartments 52 and 54 . In this regard, the term “membrane” can be used interchangeably with screen, diaphragm, partition, barrier, a sheet, a foam, a sponge-like structure, a canvas, and the like. The membrane 56 can be chosen to be permselective, e.g., a cation exchange membrane, or can be chosen to be non-permselective, e.g., a porous membrane. As used herein, the term “permselective” refers to a selective permeation of commonly charged ionic species through the membrane with respect to other diffusing or migrating ionic species having a different charge in a mixture. In contrast, the term “non-permselective” generally refers to a porous structure that does not discriminate among differently charged ionic species as the species pass through the porous structure, i.e., the membrane is non-selective with respect to ionic species. For example, in a permselective membrane such as a cation exchange membrane, cations can freely pass through the membrane whereas the passage of anions is prevented. In contrast, in a non-permselective membrane such as a porous membrane, the passage of anions and cations through the porous membrane are controlled by diffusion. [0033] At least one of the compartments 52 or 54 of electrolytic reactor 50 , contains the particulate material 40 , and is configured to receive an aqueous chlorite feed solution. If both compartments contain particulate material 40 , each compartment 52 , 54 may be configured to possess its own physical properties (e.g., the particulate material 40 in the cathode compartment 54 may have different properties from the particulate material 40 disposed in the anode compartment 52 ) through which an aqueous solution can pass without entering adjacent compartment 52 . Preferably, the particulate material 40 in the compartment 52 and/or 54 in which the alkali metal halite feed solution (e.g., alkali metal chlorite) is fed comprises the cation exchange material in the hydrogen form or a mixture of cation exchange material and anion exchange material, wherein the majority of the particulate material 40 is the cation exchange material. [0034] In a preferred embodiment, the anode and cathode compartments 52 , 54 , respectively, are preferably packed with the cation exchange material, and the membrane 56 separating the anode compartment 52 from the cathode compartment 54 is a cation exchange membrane. In this configuration of the two-compartment reactor 50 , the alkali metal chlorite feed solution can be fed to either or both compartments to provide an effluent containing chlorous acid, which is then fed to the fixed bed reactor 200 . [0035] Referring now to FIG. 4 , the three-compartment electrolytic reactor 70 generally comprises an anode compartment 72 , a central compartment 74 , and a cathode compartment 76 . The central compartment 74 is interposed between the anode and cathode compartments 72 , 76 , respectively, and is separated therefrom by membranes 90 and 92 . Each compartment 72 , 74 , and 76 , preferably includes inlets 78 , 80 , 82 , respectively, and outlets 82 , 84 and 86 , respectively. The anode compartment 72 includes anode 32 and can be optionally filled with the particulate material 40 . The cathode compartment 76 includes cathode 34 and can be optionally filled with the particulate material 40 . The anode 32 and cathode 34 are in electrical communication with a source of direct current 36 (DC). [0036] In a preferred embodiment, the central compartment 74 comprises particulate material 40 , wherein the particulate material 40 comprises the cation exchange material or a mixture of cation exchange material and anion exchange material, wherein the majority of the particulate material 40 is the cation exchange material. In addition, the electrolytic reactor membrane 90 is a cation exchange membrane. During use, it is preferred that the alkali metal chlorite solution is fed through inlet 80 of the central compartment to produce an effluent that is discharged from outlet 86 , which is in fluid communication with the fixed bed reactor 200 . The effluent discharged from the anode compartment 72 through outlet 84 is preferably in fluid communication with the inlet 80 or outlet 86 prior to entering the fixed bed reactor 200 . In this manner, an oxidizing agent generated in the anode compartment 72 is fed into the fixed bed reactor 200 , which can be used to regenerate the redox exchange material contained therein. In the case where the effluent from the anode compartment 72 is in fluid communication with the inlet of the central compartment 74 , the effluent can be used to dilute the alkali metal feed solution to a desired amount prior to entering the central compartment 74 . [0037] Referring now to FIGS. 5A and 5B , there is shown an exploded isometric view of an exemplary electrolytic reactor cassette 100 employing the three-compartment reactor configuration 70 as described in relation to FIG. 4 . The cassette 100 is formed from stock materials that are preferably chemically inert and non-conductive. Components forming the cassette 100 may be molded for high volume production or alternatively, may be machined as described in further detail below. [0038] The exemplary cassette 100 is configured for producing about 5 grams per hour of chlorous acid and is fabricated from two pieces of flat stock 102 and 104 , about 4 inches across by about 14 inches long by about 1 inch thick. The pieces 102 , 104 are machined such that depressions ¼ inch deep by 2 inches across by 12 inches long are cut in the center of each piece. The pieces 102 , 104 are then drilled and tapped to accept the anode 32 and cathode 34 . Each piece further includes inlets 78 , 82 and outlets 84 , 88 , through which fluid would flow. The anode 32 and cathode 34 are approximately 2 inches across by 9 inches long and are inserted into the stock pieces 102 and 104 . Membranes 90 , 92 are disposed over each depression formed in stock pieces 102 , 104 . Preferably, membrane 90 is a cation exchange membrane. Approximately 150 ml of particulate material (not shown) may optionally be packed into each depression to form the anode compartment 72 and the cathode compartment 76 , respectively (as shown in FIG. 4 ). As constructed, the particulate material, if present in the cathode and/or anode compartments, is configured to be in direct contact with the anode 32 or cathode 34 . [0039] Interposed between the membranes 90 , 92 is a piece of flat stock 106 , about 4 inches across by about 14 inches long by 1 inch thick. The stock piece 106 is machined such that a hole about 2 inches across by 12 inches long is cut through the piece to form the central compartment 74 (as shown in FIG. 4 ). The piece 106 is then drilled and tapped to accept two fittings that form inlet 80 and outlet 86 through which fluid would flow. The central compartment 74 is filled with about 150 ml of particulate material that includes the cation exchange material. The components of the electrolytic reactor cassette 100 are assembled and bolted together, or otherwise secured. In this configuration, the aqueous alkali metal halite solution (e.g., alkali metal chlorite) is preferably passed through the central compartment 74 and is not in direct contact with the anode 32 or cathode 34 . [0040] In a preferred embodiment, the cassette 100 is formed from an acrylonitrile-butadiene-styrene (ABS) terpolymer. Other suitable materials include polyvinylchloride (PVC), chlorinated PVC, polyvinylidene difluoride, polytetrafluoroethylene and other fluoropolymer materials. [0041] While the arrangements of anode, cathode, and electrolytic reactors 30 , 50 , and 70 illustrated in FIGS. 2, 3 , and 4 are presently considered preferable, any arrangement in which a sufficient quantity of cation exchange resin or material is packed between the anode and cathode in an electrolytic reactor or in at least one of the compartments of a divided or multi-compartment electrolytic reactor can be used. Other embodiments include, but are not limited to, separation of the anode and cathode compartments to control intermixing of gases and solutions and provision of any number of packed-bed compartments separated by membranes placed between the anode and cathode to affect other oxidation, reduction or displacement reactions. [0042] The anode 32 and the cathode 34 may be made of any suitable material based primarily on the intended use of the electrolytic reactor, costs and chemical stability. For example, the anode 32 may be made of a conductive material, such as ruthenium, iridium, titanium, platinum, vanadium, tungsten, tantalum, oxides of at least one of the foregoing, combinations including at least one of the foregoing, and the like. Preferably, the anode 32 comprises a metal oxide catalyst material disposed on a suitable support. The supports are typically in the form of a sheet, screen, or the like and are formed from a rigid material such as titanium, niobium, and the like. The cathode 34 may be made from stainless steel, steel or may be made from the same material as the anode 32 . [0043] The permselective membranes, e.g., 56 , 90 , and 92 , preferably contain acidic groups so that ions with a positive charge can be attracted and selectively passed through the membrane in preference to anions. Preferably, the permselective membranes contain strongly acidic groups, such as R—SO 3 − and are resistant to oxidation and temperature effects. In a preferred embodiment, the permselective membranes are fluoropolymers that are substantially chemically inert to chlorous acid and the materials or environment used to produce the chlorine dioxide. Examples of suitable permselective membranes include perfluorosulfonate cation exchange membranes commercially available under the trade name NAFION commercially available from E.I. duPont de Nemours, Wilmington, Del. [0044] The cation exchange material is preferably an oxidizing exchanger, i.e., a cation ion exchange resin or material. During operation of the electrolytic reactor 20 , it is hypothesized that the function of the cation exchange material includes, among others, electro-actively exchanging or adsorbing alkali metal ions from the aqueous alkali metal chlorite solution and releasing hydrogen ions. The released hydrogen ions react with the chlorite ions to form chlorous acid and/or can regenerate the cation exchange material back to the hydrogen form thereby releasing alkali metal ions or the like that may then pass into the cathode compartment, if present. The use of the cation exchange material is especially useful when feeding a dilute alkali metal chlorite solution into the central compartment 74 of the three-compartment electrolytic reactor 70 as it helps lower the voltage within the compartment and increases conversion efficiency. When the cation exchange material reaches its exhaustion point or is near exhaustion, it may be readily regenerated by a strong or weak acid so as to exchange the alkali or alkaline earth metal previously adsorbed by the active sites of the cation exchange material for hydrogen. The acid necessary for regenerating the cation exchange material may be added individually at the compartment inlet or may be generated in the anode compartment, which then diffuses across the cation exchange membrane. The anionic exchange material, if present, may be regenerated by a strong or weak base, e.g., sodium or potassium hydroxide. [0045] Examples of suitable cation exchange resins or materials include, but are not intended to be limited to, polystyrene divinylbenzene cross-linked cation exchangers (e.g., strong acid types, weak acid types, iminodiacetic acid types, chelating selective cation exchangers and the like); strong acid perfluorosulfonated cation exchangers; naturally occurring cation exchangers, such as manganese greensand; high surface area macro-reticular or microporous type ion exchange resins having sufficient ion conductivity, and the like. For example, strong acid type exchange materials suitable for use are commercially available from Mitsubishi Chemical under the trade names Diaion SK116 and Diaion SK104. Optionally, the cation exchange material may be further modified, wherein a portion of the ionic sites are converted to semiconductor junctions, such as described in U.S. Pat. Nos. 6,024,850, 5,419,816, 5,705,050 and 5,609,742, herein incorporated by reference in their entireties. However, the use of modified cation exchange material is less preferred because of the inherent costs associated in producing the modification. In a preferred embodiment, the cation exchange materials have a cross-linking density greater than about 8%, with greater than about 12% more preferred and with greater than about 16% even more preferred. Increasing the cross-linking density of the cation exchange materials has been found to increase the resistance of the cation exchange materials to effects of the electrolytic environment such as oxidation and degradation. As a result, operating lifetimes for the electrolytic reactor can advantageously be extended. [0046] The packing density and conductivity of the particulate material 40 disposed within a compartment can be adjusted depending on the operating parameters and desired performance for the electrolytic reactors 30 , 50 , 70 . For example, the particulate material may be shrunk before use in the electrolytic reactor, such as by dehydration or electrolyte adsorption. Dehydration may be by any method in which moisture is removed from the ion exchange material, for example, using a drying oven. It has been found that dehydration prior to packing can increase the packing density by as much as 40%. Electrolyte adsorption involves soaking the material in a salt solution, such as sodium chloride. The packing density of the material so treated can be increased by as much as 20%. The increase in packing density advantageously increases the volume in which the DC current travels, thus reducing the electrical resistance in the electrolytic reactor. [0047] Referring now to FIG. 6 , there is illustrated a fixed bed reactor 200 having an inlet 202 and an outlet 204 . Disposed within the fixed bed reactor is a bed containing the redox exchanger material 206 . As used herein, the term “redox exchanger material” refers to conjugate oxidizing and reducing materials that contain both oxidation and reduction couples. That is, the redox exchanger material can be used to oxidize and/or reduce dissolved ionic species in a solution. One type of suitable redox exchanger material includes those referred to as reversible redox agents. Other types of redox exchanger materials include modified ion exchange resins, which have been modified to include the oxidation and reduction couple. The reversible oxidation-reduction couples are held in the resin either as counter ions, by sorption, or by complex formation. [0048] The reversible redox exchange materials are capable of reversing the oxidation and/or reduction state of the redox exchanger material after oxidizing or reducing a species. That is, the redox agent after having oxidized (or reduced) a species can be regenerated by a suitable oxidation (or reduction) agent. The reactivity of these agents is due to the functional groups present, which can be reversibly oxidized or reduced. These types of redox agents do not carry fixed ionic groups and contain no counter ions within their matrix that would function as an ion exchanger. Suitable examples of redox exchanger materials include, but are not intended to be limited to, manganese greensand, those redox exchanger agents commercially available under the trademarks BIRM, PYROLOX and MTM from the Clack Corporation, and KDF-85 from KDF Fluid Treatment, Inc. BIRM is a manufactured medium consisting of granular material coated with magnesium oxide; MTM and PYROLOX are mineral forms of manganese dioxide; and KDF-85 is a copper-zinc type redox media. [0049] In the oxidized state, the redox exchanger materials can oxidize dissolved ionic species (e.g., chlorous acid) provided that the redox potential of the ionic species is greater than that of the redox exchanger, i.e., the oxidation-reduction couple on the redox exchanger must be a stronger oxidizing agent than the oxidized ionic species. Since the process is reversible due to the nature of the redox agent, the redox agent becomes oxidized when in contact with an oxidizing agent, such as, for example, upon contact with oxygen that has been generated by electrolysis of water at the anode. The coupling agents are preferably metal complexes, wherein the metal is capable of having reversible oxidation states. Suitable metals include titanium, ruthenium, vanadium, platinum, iridium, gold, copper, chromium, manganese, iron, cobalt, nickel, zinc, composites or mixtures or alloys or oxides of at least one of the foregoing metals, and the like. [0050] The flow rate through the fixed bed reactor is preferably about 1 to about 10 gallons per minute/square foot (gpm/ft 2 ), with about 2 to about 5 gpm/ft 2 more preferred. The minimum bed depth is preferably about 24 inches. The flow rate and minimum bed depth can be used to determine the dimension of the fixed bed reactor and the volume of redox exchanger material employed. [0051] The particulate material 40 of the electrolytic reactor 20 and the redox exchanger material 206 of the fixed bed reactor 200 are not intended to be limited to any particular shape. Suitable shapes include rods, extrudates, tablets, pills, irregular shaped particles, spheres, spheroids, capsules, discs, pellets or the like. In a preferred embodiment, the particulate material is spherical. More preferably, the particulate material includes a reticulated and textured surface having an increased surface area. The sizes of the particulate material 40 and redox exchanger materials 206 employed in the system 10 are dependent on the acceptable pressure drop across the respective bed. The smaller the particulate material 40 or redox exchanger material 206 , the greater the pressure drop. [0052] In the preferred application for generating chlorine dioxide, the system 10 is configured with the three-compartment electrolytic reactor 70 as previously described, wherein the central compartment outlet 86 is in fluid communication with the fixed bed reactor inlet 202 . The three-compartment reactor 70 preferably comprises a cation exchange membrane 90 separating the anode compartment 72 from the central compartment 74 . Cation exchange material is preferably disposed in the central compartment 74 . [0053] In operation of the preferred application, a dilute aqueous feed solution of an alkali metal chlorite solution is passed through the central compartment 74 . The alkali metal ions are exchanged with hydrogen ions of the cation exchange material to produce chlorous acid within the central compartment 74 . Water preferably flows through the anode and cathode compartments 72 , 76 , respectively. Preferably, the water is deionized. [0054] As a direct current is applied to the reactor 70 , the anode compartment 72 oxidizes the water to generate, among others, hydrogen ions and oxygen (O 2 ) whereas the cathode compartment 76 reduces the water to generate, among others, hydroxyl ions. The hydrogen ions generated in the anode compartment 72 can diffuse across the cation exchange membrane 90 into the central compartment 74 to regenerate the cation exchange resin within the central compartment 74 and/or to acidify the chlorite ions to produce chlorous acid. [0055] The chlorous acid effluent from the reactor 70 is fed to the fixed bed reactor 200 , wherein chlorous acid is oxidized by the redox exchange material to chlorine dioxide. The oxygen generated by electrolysis of water in the anode compartment 72 can be used to dilute the alkali metal chlorite feed solution as it is introduced into the central compartment 74 or may be combined with the chlorous acid containing effluent from the central compartment 74 prior to being fed to the fixed bed reactor 200 . [0056] The concentration of chlorous acid produced by the electrolytic reactor, e.g. 10, 100, is preferably less than about 6.0 grams per liter (g/L), with less than about 3 g/L more preferred and less than about 0.65 g/L even more preferred. Also preferred is a chlorous acid concentration greater than about 0.06 g/L, with greater than about 0.3 g/L more preferred and greater than about 0.5 g/L even more preferred. At concentrations greater than about 6.0 g/L, there is an increased risk of producing chlorine dioxide in the vapor phase as the chlorous acid solution is oxidized in the fixed bed reactor 200 , which undesirably can cause an explosion referred to by those skilled in the art as a “puff”. [0057] The applied current to the reactor 100 should be sufficient to reduce the pH of the resulting chlorous acid effluent solution to less than about 7. More preferably, the pH is reduced to about 1 to about 5, with a reduction of pH to about 2 to about 3 most preferred. The alkali metal ions from the alkali metal chlorite solution can diffuse through membrane 92 to the cathode compartment 76 and with the hydroxyl ions produce an alkali metal hydroxide effluent from the cathode compartment 76 . [0058] There are a number of variables that may be optimized during operation of the system 10 . For example, a current density for the electrolytic reactors is preferably maintained at about 5 to about 100 milliAmps per square centimeter (mA/cm 2 ). More preferably, the current density is less than about 50 mA/cm 2 , with less than about 35 mA/cm 2 even more preferred. Also preferred, are current densities greater than about 10 mA/cm 2 , with greater than about 25 mA/cm 2 more preferred. The temperature at which the feed solutions (e.g., alkali metal chlorite solution, water, and the like solutions) is maintained can vary widely. Preferably, the temperature is less than about 50° C., with less than about 35° C. more preferred and with less than about 25° C. even more preferred. Also preferred is a temperature greater than about 2° C., with greater than about 5° C. more preferred, and with greater than about 10° C. even more preferred. In a preferred embodiment, the process is carried out at about ambient temperature. [0059] In addition to temperature and current density, the contact time of the alkali metal chlorite solution with the cation exchange material is preferably less than about 20 minutes and more preferably, less than about 2 minutes. Also preferred is a contact time greater than about 1 minute, with greater than about 0.1 minute more preferred. Similarly, the contact time of the chlorous acid containing effluent with the redox exchanger material is preferably less than about 20 minutes and more preferably, less than about 2 minutes. Also preferred is a contact time greater than about 1 minute, with greater than about 0.1 minute more preferred. The velocity of the chlorine dioxide precursor solution through the electrolytic reactor and/or fixed bed reactor is preferably less than about 100 centimeters/minute (cm/min), with less than about 70 cm/min more preferred and less than about 30 cm/min more preferred. Also preferred is a velocity greater than about 0.1 cm/min, with greater than about 10 cm/min more preferred and with greater than about 20 cm/min even more preferred. The pressure drop through the electrolytic reactor and/or fixed bed reactor is preferably less than about 20 pounds per square inch (psi) and for most applications, with less than about 10 psi more preferred. Also preferred is a pressure drop greater than about 0.1 psi, and for most applications, with greater than about 1 psi more preferred. Further optimization for any of these process variables is well within the skill of those in the art in view of this disclosure. [0060] The disclosure is further illustrated by the following non-limiting Examples. EXAMPLE 1 [0061] In this Example, a system for generating chlorine dioxide was configured as described in FIG. 1 . [0062] The electrolytic reactor was configured as shown and described in FIG. 4 . Each compartment employed a length of 25.4 centimeters (cm) with a width of 5.08 cm. The thickness of the central compartment was 1.27 cm and the thicknesses of the electrode compartments were 0.64 cm. The electrode and central compartments of the electrolytic reactor contained SK116 cation exchange resin commercially available from Mitsubishi Chemical. A transverse DC electric field was supplied by an external power supply to the electrodes. The effluent from the anode compartment was coupled to the inlet of the central compartment, thereby diluting a 25-weight percent sodium chlorite feed solution such that the final concentration of sodium chlorite was about 1000 mg/L as it entered the central compartment. The temperature of the feed solution was held constant at about 30° C. [0063] Softened water was passed upwardly through the anode and cathode compartments of the electrolytic reactor at a flow rate of about 50 mL/min. While passing the solutions through the compartments of the reactor, a controlled current of about 8.0 amps was applied to the anode and cathode. [0064] The fixed bed reactor was configured as shown in FIG. 6 and had a diameter of 3.46 cm and length of 60.96 cm. The fixed bed reactor was filled with 575 milliliters of manganese greensand with an operating capacity of about 300 grains manganese per cubic foot. The manganese greensand had an effective particle size of about 0.030 millimeters to about 0.35 millimeters. The inlet conduit of the fixed bed reactor was coupled to the central compartment outlet of the electrolytic reactor. Thus, the fixed bed reactor received an effluent from the electrolytic reactor containing both chlorous acid and oxygen. The system was operated continuously for a period of 100 hours. [0065] A Direct Reading Spectrophotometer, Model No. DR/2000, was used to measure the chlorine dioxide concentration (mg/L) in the solution exiting the fixed bed reactor using Hach Company Method 8138. Measurement of the yield provides a standard for evaluating actual performance of the system and can be determined in accordance with the following mathematical relationship: % ⁢   ⁢ Yield = actual theoretical × 100 wherein the actual yield is determined from the amount of chlorine dioxide generated, and wherein the theoretical yield is calculated by the amount of chlorine dioxide that could be generated from the sodium chlorite solution. The theoretical yield can be calculated as follows: % ⁢   ⁢ Theoretical ⁢   ⁢ Yield = [ ClO 2 ] product θ ⁡ [ NaClO 2 ] feed ⁡ [ 90.5 67.5 ] × 100 wherein the term (90.5/67.5) is the ratio of the equivalent weight of the sodium chlorite to chlorine dioxide. The symbol “θ” represents the stoichiometric ratio between the chlorine dioxide product and sodium chlorite reactant, which can vary from 0.8 to 1.0 depending on the reactants used and the stoichiometry of the reaction. [0066] FIG. 7 graphically depicts the conversion efficiency as a function of time for the system. Initially, it is shown that the conversion efficiency to oxidize chlorite ions to chlorine dioxide was relatively low. This was expected since manganese greensand employed was not initially in the fully oxidized “regenerated” form. After about 10 hours of operation conversion of chlorite solution to a chlorine dioxide solution was at about the maximum theoretical yield. Increased conversion efficiencies over a prolonged period of time are a significant commercial advantage since it reduces the maintenance and operating costs of these reactors significantly. Moreover, the fixed bed reactor is regenerated as demonstrated by its efficiency over the 100-hour testing period (See Comparative Example below). EXAMPLE 2 [0067] In this Example, the system as described in Example 1 was employed, wherein the fixed bed reactor was filled with 575 ml of PYROLOX that had an effective particulate size of about 0.51 millimeters. The temperature of the sodium chlorite feed solution was about 20° C. [0068] FIG. 8 graphically depicts the conversion efficiency as a function of time for the system. Conversion efficiency was at about theoretical maximum. EXAMPLE 3 [0069] In this Example, the system as described in Example 1 was employed, wherein the fixed bed reactor was filled with 575 ml of BIRM with an effective particulate size of about 0.48 millimeters. The temperature of the sodium chlorite feed solution was at about 20° C. [0070] FIG. 9 graphically depicts the conversion efficiency as a function of time for the system. Conversion efficiency was at about theoretical maximum. COMPARATIVE EXAMPLE [0071] In this Comparative Example, the system as described in Example 1 was employed, wherein the oxygen generated in the anode compartment was not fed to the inlet of the central compartment. Thus, the effluent introduced to the fixed bed reactor in contained chlorous acid and did not include the effluent produced in the anode compartment. [0072] FIG. 10 graphically depicts the conversion efficiency as a function of time for the system. Conversion efficiency significantly and steadily decreased as the system was operated indicating that regeneration of the manganese greensand did not occur to the extent regeneration occurred in Examples 1-3. The conversion efficiency stabilized to approximately 20% after about 30 hours of operation. While not wanting to be bound by theory, it is believed that oxygen levels normally present in water (prior to electrolysis) provided some regeneration to the manganese greensand and was likely one of the reasons why the conversion efficiency did not decrease to zero. At about 40 hours, the effluent (O 2 containing) produced in the anode compartment was added to the chlorous acid feed. A slight increase was seen in the conversion efficiency, but did not increase back to its original level. It is believed that since there was no oxidizing agent combined with the chlorous acid effluent introduced to the fixed bed reactor to cause regeneration of the manganese greensand during the first 40 hours of operation, the continuous flow of chlorous acid solution through the fixed bed reactor at low pH resulted in an ion exchange of manganese and hydrogen ions. Desorption of the manganese will also cause a decrease in redox capacity. [0073] While the disclosure has been described with reference to an exemplary 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 disclosure without departing from the essential scope thereof, such as for producing other halogen oxides. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
An electrolytic process and apparatus ( 20 ) for oxidizing inorganic or organic species is disclosed. The process and apparatus includes contacting a solution containing the inorganic or organic species with an electrocatalytic material disposed in the electrolytic reactor ( 200 ). Also disclosed is a process for fabricating a ceramic catalyst material for use in the electrolytic reactors ( 200 ) and processes.
2
BACKGROUND OF THE INVENTION This invention relates to the treatment or prevention of carpal tunnel syndrome and, in particular, to a glove-like appliance for opening the carpal canal by stretching and releasing the transverse carpal ligament and the surrounding structure of the hand, wrist, and forearm of a person. "Carpal Tunnel Syndrome" is the result of a compromised or narrowed carpal canal leading to compression injury of the median nerve in the wrist. The carpal tunnel is the canal in the wrist through which the median nerve and flexor tendons pass from the forearm to the hand. Prolonged, repetitive motion at a keyboard is a common, but by no means the only, cause of the syndrome. To date, carpal tunnel syndrome has been treated with orthotics, such as wrist splints or wrist rests, anti-inflammatory medications, cortisone injections, or surgery. Alone or combined, these treatments have met with varying degrees of success. The obvious solution, removing the cause of the injury, is not always practical since, as in the case of using a keyboard, the cause of the injury is often the means by which the patient obtains his or her livelihood. The next best choice, prevention through proper preparation, can be achieved by enlarging the carpal canal to maintain adequate space for the median nerve and thus avoid compression. It has been discovered that the carpal canal can be enlarged by osteopathic manipulation and stretching, thereby alleviating compression on the median nerve and resolving carpal tunnel syndrome. While severe cases may require other treatment, the manipulation is effective in the majority of cases and has the advantage of being prophylactic, i.e. a preventative. While manipulation is effective, there are two difficulties. Optimum resolution of the symptoms requires frequent, vigorous stretching and the assistance of another person, the physician. Suitably instructed, a patient can enhance the treatment with stretching. Thus, there is a need for an appliance which a patient can use several times daily to augment treatment by the physician. Simply prescribing the use of an appliance does not mean that the patient will use it properly, e.g. as often as prescribed. Proper use depends on the compliance or self-discipline of the patient. It also depends on how easy it is to use the appliance. In general, an appliance that is mechanically simple and is easy to use will more likely be used as directed. Several terms are used herein relating to the movement of the fingers and thumb. The fingers and thumb bend or "flex" to grasp a broom handle. If a hand lies with the palm and fingers flat on a flat surface, the fingers are "extended" or straightened. Lifting the fingers, and not the palm, off the surface further extends the fingers. "Abducting" the thumb means moving the thumb away from the fingers while the thumb rests on the surface. "Extending" is lifting the thumb, and not the palm, off the surface. If the forearm also rests on the surface, "extending" the wrist means lifting the palm, and not the forearm, off the surface. These terms relate to the relative movements of the fingers, thumb, palm, and wrist to each other, not to the flat surface. The flat surface is used merely as an aid for visualizing the movements. In view of the foregoing, it is therefore an object of the invention to provide a glove-like appliance for self-treatment or prevention of carpal tunnel syndrome. Another object of the invention is to provide a mechanically simple, easily used appliance, thereby improving compliance, enhancing the effectiveness of the treatment, and increasing the likelihood of a successful outcome. A further object of the invention is to provide a glove for relieving the pressure on the median nerve by stretching the transverse carpal ligament and stretching the flexor tendons into the carpal canal for dilitation effect. SUMMARY OF THE INVENTION The foregoing objects are achieved in the invention in which a glove-like appliance (herein referred to simply as a glove) includes a plate or disc having a contoured major surface for receiving the hand. The plate is divided into unequal quadrants aligned with the knuckles and the radial side of the index finger (the side facing the thumb). A wall extends from the edge of the plate toward the center, then curves back to the edge, forming a rounded corner having an angle of approximately ninety degrees and defining a first quadrant. A second quadrant, under the fingers, increases in thickness with distance from the knuckles to the fingertips. A third quadrant, diagonally opposite the second and receiving the thumb, increases in thickness with distance from the base to the tip of the thumb. A fourth quadrant, diagonally opposite the first, receives the palm of the hand and includes a recess near the edge of the plate, approximately centered under the heel of the hand. A strap extends across the plate and attaches to the edge of the plate for holding the hand in place. The glove preferably rests on a horizontal surface about waist high, e.g. a desk, table, or counter. The hand is placed on the major surface with the index finger and thumb against the wall. The second quadrant extends the fingers and the third quadrant extends and abducts the thumb. With the elbow straight or slightly bent, the user leans into the glove, bending the wrist backward, stretching the flexor tendons and connected muscles. The pressure on the heel of the hand and the abduction of the thumb flatten the heel of the hand into the recess, stretching the transverse carpal ligament. The stretching is continued for several seconds and then the hand is relaxed. The process is repeated several times per session, several sessions per day. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings in which: FIG. 1 illustrates the palmar side of a right hand in a relaxed position. FIG. 2 illustrates a cross-section through the wrist of the hand illustrated in FIG. 1. FIG. 3 illustrates a right hand with the thumb, fingers, and wrist extended to stretch the transverse carpal ligament and flexor tendons. FIG. 4 illustrates a cross-section through the wrist of the hand illustrated in FIG. 3. FIG. 5 is a perspective view of a glove constructed in accordance with the invention. FIG. 6 is a top view of a glove constructed in accordance with the invention, showing the position for a left hand. FIG. 7 is a cross-section along line 7--7, showing the extension of the thumb. FIG. 8 is a cross-section along line 8--8, showing the extension of the fingers. FIG. 9 is a cross-section through the glove of FIG. 6 in a plane parallel to surface of the drawing, showing the major surface of the glove. FIG. 10 is a side view of the glove of FIG. 6 along line 10--10. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, a human right hand in the relaxed position has the fingers flexed slightly, a hollow or concave palm, and the thumb flexed. In the wrist, illustrated in FIG. 2, transverse carpal ligament 21 spans the heel of the hand at the wrist and overlies the carpal canal containing median nerve 23 and flexor tendons 24. In accordance with one aspect of the invention, the compression of the median nerve can be relieved by extending the hand as illustrated in FIG. 3. Specifically, thumb 31 is extended and abducted away from the palm, flattening palm 35. Fingers 33 are bent backward relative to palm 35 and palm 35 is bent backward relative to forearm 36. Thus, the palm is spread open from side to side and from front to back, flattening the palm. Extending the hand, as illustrated in FIG. 3, stretches flexor tendons 24 causing them to elongate and causes the thicker portions of the tendons from the forearm to enter the carpal canal, as illustrated in FIG. 4. The spreading of the palm and the entrance of the thicker portions of the tendons into the canal slightly enlarges carpal canal 25 and thus leads to relief of compression on median nerve 23. Extending the thicker portions of the tendons into the carpal canal and stretching the transverse carpal ligament cause a transient aggravation of carpal tunnel syndrome since there is a transient increase of pressure within the carpal canal and thus on the median nerve. This may seem to be the opposite of an appropriate maneuver. However, because the carpal canal is also being enlarged, the end result of the treatment is a reduction in pressure on the median nerve and reduction or prevention of the symptoms of carpal tunnel syndrome. The manipulation of the hand as illustrated in FIG. 3 requires a resting place for the patient's fingers and the use of both hands of a physician. It is desired that a similar self-treatment be available from a glove that simulates manipulation and stretching by a physician. FIG. 5 illustrates a preferred embodiment of such a love. Glove 51 includes major surface 52 having a contoured shape, for extending the hand, and cover or strap 53, for holding the hand in position against the major surface. Glove 51 is intended for use with the left hand, which is inserted through opening 54. Right hand glove 55, illustrated in dashed line, is a mirror image of glove 51 and can be separate from or molded with glove 51 in a single piece of plastic. Major surface 52 includes region 56 for the palm, region 57 for the fingers, and region 58 for the thumb. Region 56 is generally flat, with a recess described in more detail in conjunction with FIG. 7. Region 57 slopes upwardly away from region 56 for bending the fingers back relative to the palm. Region 58 slopes upwardly away from region 56 for bending the thumb back relative to the palm. Regions 56-58 blend smoothly into one another with no corners or abrupt changes in height. FIG. 6 illustrates a top view of the glove shown in FIG. 5. Plate 61 is divided into unequal quadrants by perpendicular lines 62 and 63. Line 62 is approximately aligned with the radial side of index finger 66 and line 63 is approximately under the knuckles. Wall 65 encloses a first quadrant, extending from the edge of plate 61 along index finger 66, around corner 69, then along thumb 67 back to the edge of plate 61. Rounded corner 69 fits the curve in the hand between the index finger and thumb. Wall 65 abducts thumb 67 and holds it approximately perpendicular to the index finger. The remaining fingers are held parallel to the index finger, in part by cover 53. As illustrated in FIG. 7, the surface under thumb 67 increases in height with increasing distance from corner 69 or, more specifically, from line 62 (FIG. 6). This extends the thumb, thereby flattening the palm and stretching the transverse carpal ligament. The angle of the thumb is not critical, e.g. 25°-50° relative to bottom 72. Region 58, under the thumb, is joined to region 56, under the palm, by curved portion 74. Curved portion 74 is concave, i.e. it has a radius of curvature above the major surface of the glove. Region 58 preferably includes convex portion 77, having a radius of curvature below major surface 52. This provides a comfortable rest for the thumb and adapts the glove to hands of different sizes. In region 56, diagonally opposite wall 65, recess 79 is near the edge of major surface 52, underneath the heel of the hand. Recess 79 in combination with region 58 opens the palm and stretches the transverse carpal ligament. As shown in FIG. 8, region 56 under the palm is flat or slightly concave. Region 57, under the fingers, increases in height with increasing distance from corner 69 or, more specifically, from line 63 (FIG. 6) for stretching the flexor tendons. Regions 56 and 57 are joined by curved portion 82 having a radius of curvature above major surface 52. In a preferred embodiment of the invention, region 57 includes concave, curved portion 84, having a radius of curvature below major surface 52. This provides a comfortable rest for the fingers and adapts the glove to hands of different sizes. The slope of region 57 relative to bottom 72 is not critical, e.g. from 10° to 30° is suitable. FIG. 9 shows the major surface of the glove with cover 53 and wall 65 in cross-section. Wall 65 encloses quadrant 91 and includes first wall portion 93, for aligning the index finger, and second wall portion 94, for aligning the thumb at approximately 90° to the index finger. The first and second wall portions are connected by rounded corner 95. The interior of quadrant 91 can be hollow or filled and is preferably hollow. Exterior wall portion 96 could be omitted, but is kept to give the glove a more pleasing round or oval appearance. Quadrant 97, opposite first wall portion 93, is bounded, in part, by section 101 of the cover. Section 101 confines the fingers and helps keep the fingers parallel to first wall portion 93. Quadrant 97 merges with quadrant 98 along curved portion 82. Quadrant 99, opposite second wall portion 94, merges with quadrant 98 along curved portion 74. In FIG. 10, portion 106 of cover 53 overlies quadrant 91 to provide a smooth outer surface merging with the edge of the plate. Similarly, the major surface merges with the edge of the plate at corner 107. In use, the left hand is inserted into opening 54 (FIG. 6) with index finger 66 and thumb 67 aligned with wall 65. With glove 51 on a tabletop or other suitable surface, one leans on the hand with the elbow straight (extended) or slightly bent (flexed). Leaning into the glove bends the palm back relative to the forearm while the fingers are extended and the thumb is extended by the contours in the major surface of the glove. This use of the glove flattens the palm and directly stretches the transverse carpal ligament. It also extends the fingers and wrist which pulls the thicker portions of the flexor tendons through the canal, thereby indirectly further stretching the transverse carpal ligament and dilating (enlarging) the carpal canal. The stretching is continued for several seconds and then the hand is relaxed. Thus, proper use of glove 51 approximates the manipulation and stretching by a physician. Having thus described the invention, it will be apparent to those of skill in the art that various modifications can be made within the scope of the invention. For example, left and right hand gloves can be molded separately and their bottom edges joined with adhesive. Alternatively, the gloves can be joined by hinge 110, as shown in FIG. 7, for opening the glove and treating both hands simultaneously. If left and right hand gloves are joined along their bottom edges, or molded as a single piece, pins 112 and 113 (FIG. 5) are added to each glove for defining a plane, with contact area 114, to support the glove on a horizontal surface. While the glove is shown in FIGS. 7 and 8 as constructed of solid plastic, the underside of the major surface can be hollow, provided that pressure on the major surface does not cause the plastic to distort. This lightens the glove and reduces the cost to manufacture. This does not mean that the major surface has to be rigid or hard. One could, for example, line the glove with cloth or other material for greater comfort. While cover 53 is preferably molded as an integral part of the glove, a separate strap could be attached at the edges of the plate instead. Wall 65 could be replaced with posts or other means to align the thumb and index finger. Wall 65 is preferred to posts since the wall positions the hand more accurately and is more comfortable. Although wall 65 is shown as perpendicular to the major surface, the wall could be sloped somewhat but not so much that the thumb or index finger slips during treatment.
Compression of the median nerve is relieved or prevented with a glove having a contoured major surface for receiving a hand for treatment. A wall intersecting the major surface includes a first wall portion for positioning the index finger and a second wall portion for positioning the thumb. The first and second wall portions of the wall meet at a corner. The major surface increases in height along said first and second wall portions with increasing distance from the corner. The hand rests on the major surface with the wrist and fingers extended, and the thumb extended and abducted. This positioning spreads the palm and bends the fingers back, all of which stretches the transverse carpal ligament and enlarges the carpal canal, ultimately relieving pressure on the median nerve, alleviating or preventing symptoms of carpal tunnel syndrome.
0
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to a fastener for restraining strings on a lacrosse stick, and in particular, provides a lightweight fastener that prevents strings from slipping, loosening, or becoming untied. [0003] 2. Brief Description of the Related Art [0004] In the sport of lacrosse, the lacrosse stick is the primary piece of equipment for a player. The lacrosse stick can be briefly described as including a cylindrical shaft with an enclosed V-shaped head attached to one end of the stick. Within the head of the stick there is string, mesh and/or leather thong “netting” that forms a pocket. A lacrosse player catches a ball in the pocket and is able to throw the ball to another player. Rules differ between the men's and women's game, however, both men and women need to be able to adjust the depth of the pocket by tightening and loosening the strings. [0005] In the women's game, it is against the rules for participants to have any depth to their pocket. Accordingly, prior to the start of games or sometimes randomly throughout the course of play, referees may require the participants to present their lacrosse sticks for inspection in order to confirm that the pocket of their stick is in compliance with the rules. If the referee finds the pocket to be in violation, a penalty may be assessed and the player is required to tighten the strings or mesh until the pocket is acceptable. [0006] In the men's game, players are allowed to have some depth to their pocket, but there are rules as to the depth and players can be penalized for being in violation of those rules. The pocket of the stick is not generally checked prior to a game, but may be checked at the charge of the opposing team or upon the suspicion of a referee. The construction of a men's lacrosse stick is similar to that of a women's stick and thus may require adjustment of the pocket in a similar manner. [0007] Both men and women may wish to adjust the netting of the lacrosse head to be in accordance with their preferences. The netting is tied off in several places on the lacrosse stick head. Players may find that the stick does not allow them to throw or catch to their liking, which will prompt them to either tighten or loosen the strings accordingly. This process of tightening and loosening the netting of the lacrosse stick may occur to bring the stick within compliance of the rules or in order to adjust the netting to the player's preferences. [0008] When engaging in an adjustment, the player has typically wrapped athletic tape around the strings or tied them in a knot. Thus, the player must either unwrap the tape on the strings or untie the knots of the netting. This is time consuming and inconvenient to the individual as well as to the other participants waiting to start the game. Once the player has sufficiently tightened the strings to conform to the rules, they must then re-wrap the strings with athletic tape or retie the knots. [0009] One solution to the problem is offered by Lemire in U.S. Pat. No. 6,641,492 and U.S. Pat. No. 6,533,686, which are herein incorporated by reference. Lemire provides a lace system that restrains the leather thongs from sliding by adding an extra piece to the typical lacrosse stick head. The lace lock system includes channels that align and position the thongs over ridges and a compression strap that locks the thongs against the ridges. A disadvantage of Lemire is that it incorporates considerable additional weight to the top end of the stick. [0010] Important considerations for technology related to a lacrosse stick are weight and strength. When a piece of equipment is too bulky or heavy, a player loses maneuverability and speed. Therefore, a solution to the above-described problem must have a minimal presence on the lacrosse stick. Additionally, any sort of clasp, or hook mechanism, especially metal, should be avoided on the lacrosse stick because it could present a safety hazard to other players. SUMMARY OF THE INVENTION [0011] The present invention provides a fastener for binding strings of a lacrosse stick. The fastener includes a flexible strip having two sides, a first attaching element located on a first side of the flexible strip and a second attaching element on a second side of the flexible strip. The first attaching element and the second attaching element are located at opposite ends of the flexible strip such that when the flexible strip is wrapped around an object, the first attaching element and the second attaching element may join, keeping the flexible strip bound around the object. The first attaching element and the second attaching element include Velcro, magnets, clips or a sticky substance. [0012] The invention also provides a method of binding strings of a lacrosse stick. The method includes restraining one or more strings on the lacrosse stick to a point of convergence and wrapping the strings with a fastener. First and second attaching element on the fastener are affixed to each other in order to keep the strings bound. The first attaching element and the second attaching element may comprise, for example, Velcro, magnets, clips or a sticky substance; BRIEF DESCRIPTION OF THE DRAWINGS [0013] The above and other objects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: [0014] FIG. 1 illustrates a top view and a bottom view of an embodiment of the present invention; [0015] FIG. 2 illustrates an embodiment of the present invention in use; [0016] FIG. 3 illustrates an additional embodiment of the invention; [0017] FIG. 4 illustrates an embodiment of the present invention in use, where the strings of a lacrosse stick are bound by the present invention; [0018] FIG. 5 and FIG. 6 illustrate an embodiment of the present invention in use; and [0019] FIG. 7 illustrates an additional use for the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0020] The following detailed description of preferred embodiments of the present invention will be made in reference to the accompanying drawings. In describing the invention, an explanation of related functions or constructions known in the art is omitted for the sake of clarity in understanding the concept of the invention that would otherwise obscure the invention with unnecessary detail. [0021] As shown in FIG. 1 , the fastener 141 includes a top side and a bottom side 130 . The top side 120 includes an attaching element 100 , while the bottom side 130 of the fastener 141 has an additional attaching element 110 . The attaching element can include any type of fastener, such as a magnet, Velcro®, a sticky substance, a tie, clip or any other manner of attaching which allows for repetitive fastening and unfastening. [0022] FIG. 2 demonstrates the basic use of the fastener. The lacrosse head 140 is connected to a lacrosse shaft 150 . The lacrosse head 140 has a mesh, string, or leather thong netting that creates a pocket for catching and throwing a lacrosse ball. The fastener 141 may be wrapped around the strings 160 and shaft 150 as demonstrated by arrow W 1 , in which the strings are secured against the shaft 150 . Preferably, the strings are aligned with shaft 150 , and the fastener 141 is then wrapped around both the strings 160 and the shaft 150 . The attaching element 100 and 110 are spaced and sized such that when the fastener 141 is tightly wrapped around the strings 160 and shaft 150 , the attaching element 100 and 110 join, thus keeping the fastener 141 bound. The attaching element may be optionally spaced apart such that a single wrap around the strings 160 will be sufficient to join the attaching means, or attaching element 100 and 110 may be spaced such that multiple wraps around the strings 160 will be necessary to join the attaching means. [0023] FIG. 3 shows an additional embodiment where the fastener 142 has a hole 170 in one end 180 . Referring to FIG. 5 , this enables a user to pull the opposite end 190 through the hole 170 demonstrated by arrow W 2 , thus tightening the fastener 142 around the strings 160 and shaft 150 (not shown in FIG. 5 ). The fastener 142 may also be wrapped around just the strings 160 as demonstrated by arrow W 3 in FIG. 6 . The attaching element 100 and 110 are positioned such that when the fastener 142 is wrapped tightly around the strings 160 and shaft 150 , they meet and hold the fastener 142 in place. [0024] FIG. 4 shows an embodiment of the invention where the strings 160 are bound together, but not to the shaft 150 . The flexibility of fastener 141 or fastener 142 is an aspect of the invention. The strings 160 must be strung through the bottom of the head 140 at divergent points 200 ; however, in order to effectively constrain the strings 160 , they must be brought to a point of convergence 210 . The strings 160 will extend in a V-shape from the point of convergence 210 towards the head 140 . To allow for this while remaining tight at the point of convergence 210 , fastener 141 or fastener 142 is made from a flexible material including, rubber, elastic, synthetic thread, leather or the like. The flexibility of the fastener 141 and 142 enables the strings 160 to remain tightly bound at the point of convergence 210 while allowing the strings 160 to extend towards the bottom of the head 140 at divergent points. The flexibility also facilitates the attachment of the strings 160 to the shaft 150 , to prevent the strings from moving during play. [0025] In a further embodiment of the invention, fastener 141 or fastener 142 may be used to bind the strings 161 that hold the mesh 162 of the netting of the head 140 as illustrated in FIG. 7 . The strings 161 can be tied off at several locations of the head 140 and are used in the case of mesh netting as well as leather thong netting. In this embodiment, fastener 141 or fastener 142 will bind one or more strings 161 , known as the shooting strings, and allow easy adjustment of pocket depth. [0026] Using the invention herein described, a player will no longer need to wrap the strings of a lacrosse stick in athletic tape or tie the strings in knots. A player will be able to quickly unbind the strings, mesh, and/or leather thongs of the lacrosse stick. Thus a player will be able to efficiently and conveniently adjust the netting of the lacrosse stick when required to comply with the rules or conform to their preferences. [0027] While the invention has been shown and described with reference to certain exemplary embodiments of the present invention thereof, 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 present invention as defined by the appended claims and equivalents thereof.
A simple, cost-effective and minimally intrusive solution to the problem of lacrosse stick netting adjustment is provided. A fastener provides a lightweight, flexible strap for binding laces, thongs, mesh or strings on a lacrosse stick. A player will no longer need to wrap the strings in athletic tape or tie the strings in knots, which increases efficiency and convenience when an adjustment to the netting is required.
0
CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority of Korean Patent Application Number 10-2009-0079451 filed Aug. 26, 2009, the entire contents of which application is incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supplying system of LPI (liquefied petroleum injected) engine, and more particularly to a fuel supplying system of LPI engine that is capable of improving performance of a fuel pump by decreasing suction pressure thereof. 2. Description of Related Art An LPI engine includes an LPI fuel pump feed therein so as to realize stability of fuel supplying performance when forcedly feeding fuel thereto. That is, the fuel pump is mounted inside a fuel tank, and liquid-state LPG (liquefied petroleum gas) fuel that is forcedly fed is injected by an injector. The LPI engine is suitable for corresponding to strict emission regulations, and can improve engine starting in winter while inducing emission output reduction of the engine. As shown in FIG. 3 , a conventional fuel supplying system of LPI engine includes a fuel pump 21 mounted inside a sub-fuel tank 20 in a fuel supplying line 30 in order to feed fuel stored inside a main fuel tank 10 to the engine, and then the fuel supplied from the fuel pump 21 is injected by an injector (not shown) to a combustion chamber through the fuel supplying line 30 . Unused fuel is returned through a fuel return line 40 . Herein, safety valves 50 are respectively mounted between the main fuel tank 10 and the fuel pump 21 , between the fuel pump 21 and the engine in the fuel supplying line 30 , and between the fuel pump 21 and the fuel tank 10 in the fuel return line 40 . The conventional fuel supplying system of an LPI engine must follow regulations on LPG vehicles. The regulations state that an electrical cut-off valve, an overflow prevention valve, a manual cut-off valve, etc., are to be mounted at an exit of the main fuel tank 10 . That means that the main fuel tank 10 should be closed and sealed by closing the electrical cut-off valve in case of failure of starting of the engine. Further, a safety valve should be provided so as to prevent leakage of fuel of the fuel supplying line 30 in the main fuel tank 10 in the case of a vehicle accident. At this time, fuel should flow into the fuel pump 21 from the main fuel tank 10 without air intake. Therefore, the safety valves should be mounted at the fuel supplying line 30 and the fuel return line 40 connecting the main fuel tank 10 and the sub-fuel tank 20 , and thereby the system is complicated and manufacturing cost is increased due to duplication of the safety valves 50 . In addition, after suction back pressure generated by the fuel pump 21 is reduced by a volume of the sub-fuel tank 20 , the pressure is transmitted to the main fuel tank 10 , and thereby fuel intake performance is deteriorated. Herein, because pressure of the interior of the main fuel tank 10 is high, particularly in summer, fuel intake performance is superior. However, in winter, because pressure of the interior of the main fuel tank 10 is similar to atmospheric pressure, fuel intake performance depending on the performance of the fuel pump 21 cannot be reliable. 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 OF THE INVENTION The present invention has been made in an effort to provide a fuel supplying system of an LPI engine having advantages of improving performance of a fuel pump by decreasing suction pressure thereof. A fuel supplying system of LPI engine may include a fuel tank storing fuel, a fuel pump feeding fuel supplied by the fuel tank to the engine through a fuel supplying line, and a fuel return line for returning fuel from the engine to the inside of the fuel tank. The fuel pump may be divided into a pump chamber and an operating chamber, and a vent hole is formed at a case of the fuel pump. The fuel pump may be an external fuel pump disposed outside the fuel tank. The fuel pump may be divided into a pump chamber and an operating chamber by a diaphragm. The external and internal of the operating chamber are communicated each other by the vent hole. The vent hole may reduce back pressure generated by the diaphragm moving between the pump chamber and the operating chamber. The fuel pump may be volumetric pump. 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 of the Invention, which together serve to explain certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of an exemplary fuel supplying system of LPI engine according to the present invention. FIG. 2 is a cross-sectional view of an exemplary fuel pump applied to a fuel supplying system of an LPI engine according to the present invention. FIG. 3 is a schematic view of a conventional fuel supplying system of an LPI engine. DETAILED DESCRIPTION OF THE INVENTION 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 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. As shown in FIG. 1 , a fuel supplying system of an LPI engine includes a fuel tank 100 , a fuel pump 200 , and a regulator unit 300 . The engine is connected to a fuel supplying line S and a fuel return line R, and liquid-state fuel stored in the fuel tank 100 is supplied to the engine by the fuel pump 200 through the regulator unit 300 . Unused liquid-state LPG fuel is returned to the fuel tank 100 through the regulator unit 300 via the fuel return line R. The regulator unit 300 maintains supply pressure of the liquid-state fuel supplied to the engine. In addition, a pressure sensor (not shown) detecting fuel pressure of fuel returned to the fuel tank 100 may be mounted in the fuel return line R connected to the regulator unit 300 , and furthermore a pressure regulator (not shown) may be mounted therein so as to return the fuel to the fuel tank 100 only when the fuel pressure exceeds a predetermined pressure. Although not shown in drawings, the fuel supplying system can be controlled by an ECU. The fuel supplying system is an external type, unlike a conventional system in which a fuel pump forcedly feeds fuel to the engine by pressurizing liquid-state fuel in the fuel tank 100 in the fuel supplying line S interposed between the fuel tank 100 and the regulator unit 300 . As shown in FIG. 2 , the fuel pump 200 is divided into a fuel chamber 220 and an operating chamber 230 by a diaphragm 210 . Further, the fuel pump 200 is preferably a volumetric type only using an operating chamber 230 of a motor (not shown) and a fuel chamber 220 directly connected to the fuel supplying line S as main components. Thus, a lower space of the fuel pump 200 is minimized. More specifically, volume of the fuel chamber 220 , as an example, may be 60 cc so as to prevent air intake under high load of the engine, and thereby a loss of back pressure of the pump is reduced. In addition, a vent hole 202 is formed at a case 201 of the fuel pump 200 so as to communicate the operating chamber 230 to the exterior. Herein, internal pressure and atmospheric pressure are equalized by the vent hole 202 . The fuel pump 200 is operated continuously during driving, and at this time, the fuel pump 200 pressurizes the liquid-state fuel in the fuel tank 100 to a predetermined pressure in comparison with pressure of the fuel tank 100 . For example, a pressure of 5 bar is added to the pressure of the fuel pump 100 that is 3 bar, and thereby a pressure of liquid-state fuel that is 8 bar is supplied by the fuel supplying line S. The fuel flows to the fuel chamber 220 formed inside the fuel pump 200 by the fuel pump 200 . Although not shown in the drawings, a filter of a mesh structure can be mounted at a lower portion of the fuel pump 200 so as to improve durability thereof, and block inflow of foreign substances from the fuel tank 100 in advance. Meanwhile, the fuel flows into the fuel chamber 220 by using rotation of an eccentric cam 240 disposed in a longitudinal direction inside the fuel pump 200 . The diaphragm 210 is moved in leftward and rightward directions in the drawings by a roller 250 that rolls and contacts between the eccentric cam 240 and the diaphragm 210 . Herein, when the diaphragm 210 is moved in the rightward direction in the drawings, the fuel flows into the fuel chamber 220 , and when the diaphragm 210 is moved in the leftward direction in the drawings, the fuel that is temporarily stored in the fuel chamber 220 is forcedly fed to the fuel supplying line S in a high pressure state. Further, in a process in which the diaphragm 210 is moved in leftward and rightward directions in the drawings, the internal pressure of the operating chamber 230 is maintained to be atmospheric pressure. Therefore, the diaphragm 210 is operated smoothly due to a reduction of back pressure in a vacuum state, as shown above. That is, the pressure of the fuel chamber 220 is equal to that of the fuel tank 100 in case of intake of fuel, and at that time, pressure of the operating chamber 230 is lower than that of the fuel chamber 220 . Therefore, the fuel flow is smoothly operated by as much as a difference therebetween, and thereby fuel intake to the fuel chamber 220 is performed well. While the liquid-state fuel is supplied to the engine through the regulator unit 300 , a portion of the fuel is injected by the injector and ignited, and a remaining portion thereof is returned to the fuel tank through the regulator unit 300 via the fuel return line R. In this way, the liquid-state fuel returned through the fuel return line R is passed through the regulator unit 300 via an opened return valve (not shown), and then it is stored in the fuel tank 100 . Meanwhile, the liquid-state fuel flowing into the fuel return line R is expanded according to an increase in the temperature. At that time, the pressure is increased to 8 bar as described above, and then the fuel flows into the fuel tank 100 again since the pressure adjuster of the regulator unit 300 and a return valve in the fuel return line R are sequentially opened. Further, during the fuel supplying, if the fuel supplying line S between the main fuel pump 200 and the regulator unit 300 are blocked or malfunction by sludge mixed in the liquid-state fuel, pressure of the fuel supplying line S is greater than pressure of the fuel pump 200 . However, a one-way check valve (not shown) prevents back flow of the supplied liquid-state fuel in order to reduce damage to the fuel pump 200 . For convenience in explanation and accurate definition in the appended claims, the terms “lower”, “inside” or “outside”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 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 fuel supplying system of an LPI engine is capable of improving performance of a fuel pump by decreasing suction pressure thereof. A fuel supplying system of an LPI engine may include a fuel tank storing fuel, a fuel pump feeding fuel supplied by the fuel tank to the engine through a fuel supplying line, and a fuel return line for returning fuel from the engine to the inside of the fuel tank. The fuel pump may be divided into a pump chamber and an operating chamber, and a vent hole is formed at a case of the fuel pump.
5
CROSS REFERENCE TO RELATED APPLICATIONS This is a division, of application Ser. No. 459,759, filed Apr. 11, 1974 now U.S. Pat. No. 3,931,289 which is a continuation of my copending application Ser. No. 185,448, filed Sept. 30, 1971, now abandoned which was a continuation-in-part of my copending application Ser. No. 103,338 filed Dec. 31, 1970, and now abandoned. DESCRIPTION OF THE INVENTION This invention relates to novel compositions of matter, to novel methods for producing them, and to novel chemical intermediates useful in those processes. Particularly, this invention relates to certain novel analogs of prostaglandins E 1 , E 2 , F 1 .sub.α, F 1 .sub.β, F 2 .sub.α, F 2 .sub.β, A 1 , A 2 , B 1 , B 2 , and the dihydro derivatives of the PG 1 compounds. These novel analogs each have an oxa oxygen (--O--) in place of the methylene (--CH 2 --) moiety at the three-position or at the 4-position of the prostanoic acid structure and also have a benzene ring as part of the C-13 to C-20 chain of the prostanoic acid. The essential material for this application, including the background of the invention, the disclosure of the invention, and the description of the preferred embodiments, including Preparations and Examples, is incorporated by reference from U.S. Pat. No. 3,931,289, columns 1-101, inclusive, under the provisions of M.P.E.P. 608.01(p). The following formulas represent the novel 3-oxa phenyl-substituted prostaglandin analogs of this invention: ##STR1## Formulas XIX, XXI, XXIII, and XXV represent 3-oxa phenyl-substituted compounds of the PGF type. In those formulas R 1 is hydrogen, alkyl of one to 8 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive, or ethyl substituted in the β-position with 3 chloro, 2 or 3 bromo, or 1, 2, or 3 iodo. R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are hydrogen or alkyl of one to 4 carbon atoms, inclusive. The divalent moiety --C n H 2n -- represents alkylene of one to 10 carbon atoms, inclusive, with one to 5 carbon atoms, inclusive, between --CHR 2 --and --O--. The divalent moiety --C m H 2m -- represents alkylene of one to 9 carbon atoms, inclusive, with 1 to 4 carbon atoms, inclusive, between --CHR 2 -- and --O--. The divalent moiety --C p H 2p -- represents alkylene of one to 8 carbon atoms, inclusive, with one, 2, or 3 carbon atoms between --CH=CH-- or --C.tbd.C-- and --O--. The divalent moiety --C q H 2q -- represents alkylene of one to 7 carbon atoms, inclusive, with 1 or 2 carbon atoms between --CH=CH-- or --C.tbd.C-- and --O--. The moiety --C t H 2t -- represents a valence bond, i.e., wherein t is zero, or alkylene of one to 10 carbon atoms, inclusive, i.e., wherein t is one to 10, substituted with zero, one, or 2 fluoro, with one to 7 carbon atoms, inclusive, between --CR 3 OH-- and the ring. When one or 2 fluoro are present as substituents of --C t H 2t --, that moiety will contain 2t-1 or 2t-2 hydrogen atoms, respectively, rather than 2t hydrogen atoms. The symbol T represents alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or -OR 9 , wherein R 9 is hydrogen, alkyl of one to 4 carbon atoms inclusive, or tetrahydropyranyl. The symbol s represents zero, one, 2 or 3. Regarding the combination (T) s attached to the phenyl ring, no more than two T are other than alkyl. Except for that proviso, when two or three T are present as substituents, they are the same or different. The wavy line ˜ in formulas XIX, XXI, XXIII, and XXV indicates attachment of the group to the ring in alpha or beta configuration. In the case of the compounds of formulas XIX, XXI, XXIII, and XXV, also, there are two wavy lines, and those formulas encompass compounds wherein the configurations of the hydroxy and the carboxyl-terminated moieties are, respectively, α,α, α,β, β,α, and β,β. Formulas XIX, XXI, XXIII, and XXV include lower alkanoates, and also pharmacologically acceptable salts when R 1 is hydrogen. Also included in Formulas XIX, XXI, XXIII, and XXV are separate isomers wherein the side chain hydroxy is in S or R (epi) configuration. Included in Formula XXI, are both the cis and the trans compounds with respect to the carbon-carbon double bond in the carboxy terminated side chain. In all of the compounds containing --CH=CR 4 --, that carbon-carbon double bond is in trans configuration, and the chain containing R 4 is attached to the cyclopentane ring in beta configuration in compounds encompassed by Formulas XIX, XXI, XXIII, and XXV. The novel 3-oxa phenyl-substituted prostaglandin analogs of this invention include racemic compounds and both optically active enantiomeric forms thereof. As discussed hereinabove, two structural formulas are required to define accurately these racemic compounds. For convenience, only a single structural formula is used, for example, Formulas XIX, XXI, XXIII, and XXV, to define the racemic form and both enantiomeric forms of each group of novel prostoglandin analogs. Each formula is, however, to be construed as including said racemic forms and both of said optically active enantiomeric forms.
This invention is a group of 3-oxa and 4-oxa phenyl-substituted PGE type, PGF type, PGA type and PGB type compounds, and processes for making those. These compounds are useful for a variety of pharmacological purposes, including anti-ulcer, inhibition of platelet aggregation, increase of nasal patency, labor inducement at term, and wound healing.
2
BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method of and an installation for exchanging roll sets in rolling mill stands of a rolling mill train with several rolling mill stands which include respective backup and working roll sets, by displacing a working roll set or a backup roll set, which are supported on top of each other, in an axial direction, on an operator's side, into a roll workshop and subsequently displacing back and mounting new roll sets. 2. Description of the Prior Art Such method of exchanging roll sets is disclosed in DE 43 21 663 A1. Firstly, on the operator's side of the rolling mill stands, there are provided support plates that are supported on a carriage, are displaced transverse to the roll axes, and are equipped with at least two rail pairs arranged adjacent to each other. The working roll sets themselves are supported on rolls. In front of the rolling mill stands, there are formed pits on the bottom of which draw-out rails for backup roll sets are provided. The pits are closed with swing covers that likewise carry rails along which the working roll sets are drawn out or inserted. Neither the construction with pits nor the use of rails over the pits are particularly convenient. U.S. Pat. No. 4,772,626 discloses transportation of backup roll sets and working roll sets together on a carriage. The transfer of different roll sets depends on a tall construction of roll exchange carriages having a large bearing capacity, and the method is very complicated. The object of the present invention is to provide with small constructional modifications, a flexible method of exchanging roll sets in selected rolling mill stands and which would correspond to the operating cycle in a roll workshop. SUMMARY OF THE INVENTION The object of the invention is achieved, according to the invention, in that on the operator's side, individual worn-out working roll sets are brought on a number of separate transversely displaceable carriages that corresponds to a number of the rolling mill stands, one after another along a single connection track by a single locomotive into the roll workshop and, therefrom, new working roll sets are displaced back and are set at exchange distances on respective transversely displaceable carriages between the rolling mill stands, and in that after unblocking of the operator's side by the transversely displaceable carriages, after dismantled respective worn-out working roll sets, the worn-out backup roll sets are withdrawn and are brought with a crane in the roll workshop, are serviced, are transported back, and are again mounted in corresponding rolling mill stands. The method separates exchange of the working roll sets from the exchange of the backup roll sets and, for that reason alone, is more flexible. The method is more economical because of smaller expenses. The process is applicable to separate rolling mill stands and to the exchange of roll sets. The simplification of the inventive method and its adaptation to the operation in roll workshop, as well as time saving, is achieved in that in a start position, in front of each rolling mill stand, simultaneously, the transversely displaceable carriage is adjusted to the exchange distance, worn-out working roll sets are removed, after transverse displacement, new working roll stands are placed on another carriage half, and the worn-out working roll sets are displaced, respectively, by their transversely displaceable carriages, over slides on the chock in the roll workshop, are dismantled, and new working roll sets are brought again in the start position. A further simplification is achieved in that in the start position, a respective worn-out set is pulled onto associated carriage half, and a new working roll set, which is delivered form the roll workshop, is pushed onto the other carriage half at a distance from the axis that corresponds to the exchange distance in front of the rolling mill stand. A timely and localized exchange of the to-be-exchanged roll sets in respective rolling mill stands can be achieved in that the transversely displaceable carriages are displaced in a rolling direction one after another from their defined positions for rolling mill stand dismantling or installation positions. Thereby, corresponding premises for exchange of backup roll sets can be provided. According to an embodiment of the invention, with respective intermediate plates pivotal in a horizontal plane precisely reproducible distances and exchange positions with respect to adjacent rolling mill stands are established between the transversely displaceable carriages, and established exchange distances are compensated during pivoting or vertical displacement of the intermediate plates and/or closing plates. Thereby, a precise start of installation of working roll sets in a rolling mill stand is facilitated. According to a further development of the invention, for exchanging backup roll sets, transversely displaceable carriages are displaced away, and in front of respective rolling mill stands, respective gaps are provided, and worn-out backup roll sets are removed with a crane, and new refurbished backup roll sets are installed with the crane. Thereby, the movements of transportation means for the working roll sets and the backup roll sets are adapted to each other. As soon as the backup roll sets are displaced to their operational position and are locked in respective rolling mill stands, the gaps in front of the rolling mill stands are closed again by pivoting the intermediate plates, and the transversely displaceable carriages are again displaced in the exchange space. According to a further embodiment, empty transversely displaceable carriages, with the intermediate plates being pivoted away, are displaced in respective parking positions at one and/or another end of the rolling mill train and are parked. The installation for exchanging roll sets in rolling mill stands of a rolling mill strain with several rolling mill stands proceeds from the state of the art that provides for connection of respective backup and working roll sets with a drive for transverse dismantling or transverse installation of roll sets, wherein parallel to a rolling direction, rails for transversely displaceable carriages in a foundation and a connection track toward a roll workshop are provided, and the transporting carriages are connected with a drive. The object of the invention is achieved according to the invention in that the transversely displaceable carriages are displaceable along continuous rails placed in the foundation parallel to the rolling direction at fixed spacings between the rolling mill stands which are controlled with pivotal intermediate plates, and that only one connection track runs, transverse to the rails, in the roll workshop and on which only one locomotive, to which a respective working roll set is attachable or detachable, runs. The space saving in front of the rolling mill stand is achieved in that the intermediate plates are, respectively, height-adjustable or pivoted away in a vertical plane or are adjustable in a horizontal plane. Despite the artificial free space in front of the rolling mill stands, advantageously, the transversely displaceable carriages, the intermediate plates pivotal in the horizontal plane, and closing plates, which are provided at the ends of a foundation pit, are fixed against rotation but are pivotal in the horizontal plane and are vertically adjustable, form a continuous accessible working surface. The constructional units can also be operated automatically, so that use of the crane is avoided or it need be used only rarely. A further automatic step is achieved in that at the ends of the rails that run parallel to the rolling direction, respective fixedly and pivotally supported closing plates are arranged and which provide for movement of the transversely displaceable carriages together with the pivotal intermediate plates, by at least half of the transversely displaceable carriage. The drawings show an embodiment of the invention that will be described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS The drawings show: FIG. 1 a side view of a rolling mill train with three rolling mill stands; FIG. 1A a roll housing with a working roll set and a backup roll set in an operational position; FIGS. 2-9 a plan view of different phases of exchange of the working roll set; FIG. 9A parking positions of transversely displaceable carriages; and FIG. 10 a plan view of the phase “pivoting of intermediate plates” with return to a start position according to FIG. 2 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 1A , the rolling mill train 1 is formed, e.g., of three rolling mill stands 2 , 3 , and 4 . Each rolling mill stand 2 , 3 , 4 has a backup roll set 5 located in an operational position, and worn-out working roll sets 6 with chocks. In FIG. 1 , the working roll and backup roll sets 6 , 5 are already dismantled and are located, respectively, on first transversely displaceable carriage 9 , second transversely displaceable carriage 10 , and third transversely displaceable carriage 11 . The working roll sets 6 (or 6 a ) consist, respectively, of upper and lower rolls which support each other by means of chocks, just as backup rolls 5 (not shown in detail in the dismantled phase). FIG. 1 shows a start position 1 a in which the roll exchange is carried out on an operator's side 1 b . A worn-out working roll set 6 is shown in side view ( FIG. 1 ) and in plan view in FIGS. 2-8 and is shown in the drawings with hatching, and a new working roll set 6 a is shown without hatching. On the operator's side 1 b , there are located a number of separate transversely displaceable carriages 9 , 10 , 11 which correspond to the number of the rolling mill stands 2 , 3 , 4 and which carry new working roll sets 6 a delivered from a roll workshop 20 . The worn-out working roll sets 6 are withdrawn with a working roll-draw-out cylinder 8 and a locomotive 21 . The separate transversely displaceable carriages 9 , 10 , 11 , which are equipped with their own drives, respectively, are displaceable over a single connection track 14 a toward the roll workshop 20 , and the transversely displaceable carriages 9 , 10 , 11 are displaceable in a rolling direction 13 on rails 14 . Further transportation from the rails 14 onto the connection track 14 a takes place over slides on respective chocks. The displacement along the connection rail 14 a is effected with a single locomotive 21 . The transversely displaceable carriages 9 , 10 , 11 are controlled by spacer means 7 . After operator's side 1 b becomes free upon displacement of the transversely displaceable carriages 9 , 10 , 11 after dismantling of respective worn-out working roll sets 6 , the worn-out backup roll sets 5 are dismantled and are brought in the roll workshop 20 by a crane, and new ground rolls are brought back in associated rolling mill stands 2 , 3 , 4 , are mounted there, and are locked. The displacement of the transversely displaceable carriages 9 , 10 , 11 over the rails 14 in the foundation pit 15 a of the foundation 15 provides for respective gaps 12 (see also FIG. 9A ) for dismantling or mounting of the backup roll sets 5 . The transversely displaceable carriages 9 , 10 11 are arranged with a right half for worn-out working roll sets 6 at respective exchange distances 2 a , 3 a , 4 a (with three rolling mill stands) and with left half for new working roll sets 6 a . The spacer means 7 consists, in the embodiment shown, of pivotal intermediate plates 7 a . The intermediate plates 7 a are relatively light and thin, so that a crane for their manipulation is not necessary. The working roll sets 6 a are just delivered, as shown in FIGS. 2 and 3 , from the remotely located roll workshop 20 . The working roll sets 6 a are attached to the locomotive 21 and are transferred onto the transversely displaceable carriages 9 , 10 , 11 . FIG. 2 shows a start position 1 a in front of each rolling mill stand 2 , 3 , 4 , with the transversely displaceable carriages 9 , 10 , 11 being adjusted with the intermediate plates 7 a pivotal in a horizontal plane. The worn-out working roll sets 6 are then moved away ( FIG. 3 ). After the transverse displacement onto the other carriage halves, the new working roll sets 6 a are mounted in respective rolling mill stands 2 , 3 , 4 . The worn-out working roll sets 6 are then displaced into the roll workshop 20 for maintenance. A new working roll set 6 a is again brought to a start position ( FIG. 2 ), and the cycle begins anew. A particular feature here is that in the start position 1 a , respective worn-out working roll sets 6 are pulled onto associated carriage halves, and new working roll sets 6 a are located at the exchange distance 2 a , 3 a , 4 a in front of the respective rolling mill stands 2 , 3 , 4 , placed on the other carriage halves, whereby a precise adjustment is carried out. According to FIG. 3 , respective transversely displaceable carriages 9 , 10 , 11 are aligned with distances 2 a , 3 a , 4 a with respect to each other with the intermediate plates 7 a having been pivoted out. The transversely displaceable carriages 9 , 10 , 11 are displaced out of these predetermined mounting or dismantled positions in the rolling direction 13 one after another. According to FIG. 4 , all of the new working roll sets 6 a are located in their mounting position with respect to the rolling mill stands 2 , 3 , 4 and are pushed in with the working roll push-in cylinder 8 and the locomotive 21 and are secured in the stands. In FIG. 5 , the new working roll sets 6 a are pushed in the working roll stands 2 , 3 , 4 and are secured in the operational position. With separate movements, the transversely displaceable carriages 9 , 10 , 11 are repeatedly precisely adjusted, respectively, by the intermediate plates 7 a pivotal in the horizontal plane, relative to each other at the distances and in the exchange positions relative to the adjacent rolling mill stands 2 , 3 , 4 , with the stationary arranged closing plates 18 at the ends of rails 14 closing the remaining gaps. The distances between the transversely displaceable carriages 9 , 10 , 11 can be adjusted, respectively, by pivotal movements or transverse movements of the intermediate plates 7 a and/or the closing plates 18 , as shown in FIG. 6 . The transverse arrangement of the intermediate plates 7 a and of the closing plate 18 provides free space so that for the exchange of the backup roll sets 5 , in front of respective rolling mill stands 2 , 3 , 4 , respective gaps 12 are formed by moving the transversely displaceable carriages 9 , 10 , 11 away (see also FIG. 9A ). A worn-out backup roll set 5 can be removed by a crane, and a new refurbished backup roll set 5 can be again installed with the crane. According to FIG. 7 , the transversely displaceable carriages 9 , 10 , 11 are connected one after another to the locomotive 21 displaceable along the connection track 14 a . Respective worn-out working roll sets 6 are displaced in the roll workshop 20 and are exchanged there for new working roll sets 6 a. As shown in FIG. 8 , respective worn-out working roll sets 6 are displaced into the roll workshop 20 with the locomotive 21 , are exchanged there for respective new working roll sets 6 a , and are displaced back, as also shown in FIG. 8 . According to FIG. 9 , the second working roll set 6 is already displaced back from the roll workshop 20 , together with a new working roll set 6 a . Only the third worn-out working roll set 6 has to be displaced in the roll workshop 20 . FIG. 9A shows that empty transversely displaceable carriages 9 , 10 , 11 are displaced, at the pivoted-out or transversely lifted intermediate plates 7 a and closing plates 18 , in a left parking position (transversely displaceable carriages 9 , 10 ) and in a right parking position (transversely displaceable carriage 11 ), with the intermediate plates 7 a being pivoted out and the closing plates 18 being lifted in order to save space. Thereby, the gaps 12 in front of rolling mill stands 3 and 4 remain free for other manipulations. As further shown in FIG. 9A , the intermediate plates 7 a are pivotally supported on respective transversely displaceable carriages 9 , 10 , 11 and are displaced toward and away with displaceable on the carriage, pneumatic or hydraulic piston-cylinder drives 17 . The piston-cylinder drives 17 are provided on the closing plates 18 , doubly on the first transversely displaceable carriage 9 , and on one side, on the right, on the second and third transversely displaceable carriages 10 and 11 . After being loaded with a new working roll set 6 a , the transversely displaceable carriages 9 , 10 , 11 are displaced, as shown in FIG. 10 , again in the mounting position in front of the rolling mills stands 2 , 3 , 4 . Finally, the intermediate plates 7 a are displaced into a horizontal plane, and the closing plates 18 are lowered in the horizontal plane. The new working roll sets 6 a are located in a position for a rapid replacement of worn-out working rolls sets 6 . The invention also provides for exchange of separate worn-out working roll sets 6 . The transversely displaceable carriages 9 , 10 , 11 , together with the pivotal in the horizontal plane, intermediate plates 7 a and arranged at the ends of a foundation pit 15 a , liftable and horizontally pivotal, stationary closing plates 18 , form, in the horizontal plane, a continuous accessible working surface 19 . In FIGS. 1 , 2 - 5 and 10 , at the ends of the rails 14 , there are arranged, parallel to the rolling, direction 13 , stationary, pivotally and vertically adjustable, closing plates 18 that form, together with the intermediate plates 7 a , the working surface 19 . LIST OF REFERENCE NUMERALS 1 . Rolling mill train 1 a . Start position 1 b . Operator's side 2 . Roll stand 2 a . Exchange distance 3 . Roll stand 3 a . Exchange distance 4 . Roll stand 4 a . Exchange distance 5 . Set of backup rolls 6 . Worn-out work roll set (Drawings; with hatching) 6 a . New work roll set (Drawings: without hatching) 7 . Spacer means 7 a . Pivotal intermediate plate 8 . Work roll-draw-out cylinder 9 . First transversely displaceable carriage 10 . Second transversely displaceable carriage 11 . Third transversely displaceable carriage 12 . Gap in front of a roll stand 13 . Rolling direction 14 . Rails 14 a . Connection track 15 . Foundation 15 a . Foundation pit 16 . Spacings 17 . Piston-Cylinder drive 18 . Stationary secured closing plate 19 . Accessible Working surface 20 . Roll workshop 21 . Locomotive
A method of and an installation for exchange of roll sets ( 5, 6 ) contemplate provision of a number of separate transversely displaceable carriages ( 9, 10, 11 ), whereby individual worn-out working roll sets ( 6 ) are displaced along a single connection track ( 14 ) by a single locomotive ( 21 ) in a roll workshop ( 20 ), and a new working roll set ( 6 a ) is displaced back to an installation position, and wherein during formation of a gap ( 12 ) in front of a rolling mill stand ( 2, 3, 4 ), a withdrawn backup roll set ( 5 ) is transported by a crane in the roll workshop and back.
1
CROSS REFERENCE TO RELATED APPLICATION This application claims priority to British Patent Application Serial No. 9704181.8, filed on Feb. 27, 1997, and entitled: "Apparatus and Method of Forming Ducts and Passageways", which is hereby incorporated by reference in its entirety. FIELD OF INVENTION The invention which is the subject of this application relates to an improvement in the provision of apparatus and a method for the installation of ducts, cables and pipes and particular in the forming of the same with respect to existing or prepositioned plant which can be in the form of cables, wires, ducts or pipes. BACKGROUND OF THE INVENTION The apparatus and method of the invention has several advantageous uses. One such use is to install ducts, cables or pipes (herein collectively referred to as ducts) adjacent to existing plant such as electricity, telecom or other utilities. The installers of new ducts such as this are frequently faced with the problem of increasing the capacity of the system along a particular length of the said system. Conventionally, new plant installations were installed along the existing ducts and along which existing plant ran in groups between access manholes. At the time of laying the existing ducts, additional spare capacity was normally provided but, as the requirement for new systems and equipment has greatly increased in recent years, it is increasingly found that the spare capacity has been used up and therefore installation of new ducts is required. SUMMARY OF THE INVENTION As it is preferable to use the existing routes for plant in order to minimise the length of cable which is required to be installed between the manholes and in order to allow the installer to use existing rights of way under private or publicly owned property, there is a need for the provision of method and apparatus which allows the formation of the new ducts for the new plant in a controlled manner along and adjacent to the existing plant, thereby negating the need for excavation and the gaining of new rights of way. The installation of new ducts for plant in close proximity to existing plant using trenchless techniques i.e, where the surface is not required to be dug up, is currently not practically achievable using known techniques as this requires an accuracy of drilling of the duct which is not achievable using known techniques. The known techniques do not allow control of the drill to provide sufficient accuracy to avoid damage, or the risk of damage, to either the existing ducts and plant therein and/or deviating from the required line. The existing techniques for drilling of ducts for installation of plant typically use an incremental location and steering system which, in one embodiment, comprises a radio transmitter known as a radiosonde in the nose of the drill. The radiosonde radiates a low frequency magnetic signal which is detected at the surface by a locator and therefore the position of the drill head in the ground can be determined by sweeping the locator over the surface until the maximum signal is detected. When the maximum signal is detected then the operator has located and can then control the further passage of the drill head. The radiosonde also transmits other signals to the locator at the surface which identify the orientation or roll angle of the steering face and this information is transmitted to the drill rig by a conventional UHF radio transmitter to the drill operator who can then set the angle of the steering face accordingly. However, the measurement of the position and changes in steering can only be carried out when the drill is stationary and, in order to maintain a reasonable rate of progress for the drilling operation the location readings from the drill are typically only taken at intervals of 1 to 2 meters. This has two disadvantages, firstly that the drill is required to be stopped at relatively frequent intervals to allow the position of the same to be checked and secondly, the accuracy of drilling is limited due to the fact that the drill is able to deviate from the chosen line between incremental measurements and this is unsatisfactory when drilling in close proximity to existing plant. Additionally, the accuracy of the location process decreases with increasing depth as the strength of the signal received at the surface reduces and the accuracy of the position measurement of the drill depends on the skill of the operator in locating the signals. It is also potentially hazardous to the operator seeking to locate the drill especially if they have to cross motorways, rivers or the like. An alternative method is to use a "mat" formed of a series of cables with current passing through the same, laid on the ground in the general line of the duct to be formed. This mat generates a complex electrical field and can allow guidance of a drill head. However these cable array mats are bulky, expensive and prone to damage and have not been commercially successful. The aim of the present invention is to provide apparatus and a method for forming a passageway, herein referred to as a duct, and guiding the apparatus forming the new duct with respect to other plant thereby ensuring that the new duct created follows the desired path. In a first aspect of the invention there is provided apparatus for the creation of a duct on or under the surface of the ground, said apparatus comprising a length of plant which generates an electromagnetic signal along the same, to utilise the same for guidance, a drill head for movement through the ground to create the duct, said drill head including a detector means including at least one electromagnetic field sensor mounted in an offset position with respect to the centre of the drill head, to allow detection and monitoring of the electromagnetic field of the guidance plant and a means to rotate the electromagnetic field sensor about the centre of the drill head. In one embodiment the length of plant for guidance is an existing piece of plant such as a length of cable, metallic pipe or wire laid in an existing duct under the surface, The existing piece of plant may normally generate an electromagnetic field which can be used as guidance, or alternatively, a current can be impressed along said plant to create an electromagnetic field. In an alternative embodiment, the guidance plant is a length of cable or wire which is placed on the surface and this acts as a reference for guidance of the drill head under the surface. In one embodiment the electromagnetic field sensors used are electromagnetic coils and are hereinafter referred to as coils. In one embodiment, the drill head includes two coils, one positioned with its longitudinal, or sensitive, axis along the longitudinal axis of the drill and the other positioned offset to the centre and with its longitudinal or sensitive axis substantially perpendicular to the longitudinal axis of the drill head. In a further embodiment, the drill head includes three coils mounted thereon, one coil positioned with its longitudinal axis along the longitudinal axis of the drill head, and the other two positioned with their longitudinal axes substantially perpendicular to the longitudinal axis of the drill head and respectively offset on opposing sides of the centre of the drill head. In whichever embodiment, it is preferred that any coil which is provided offset to the centre of the drill head lie on or adjacent to the outer surface of the drill. In use, the coil positioned along the longitudinal axis of the drill head detects changes in the angle of the drill head relative to the plane formed between the drill and the guidance plant and the coil offset from the drill head centre is rotated to detect changes in the position of the drill head relative to the guidance plant, i.e. towards or away from the plant. In one embodiment if the detection means indicates that the drill head is moving to within a predetermined distance of plant with an electromagnetic field, an alarm is sounded to the operator and the drill head movement is stopped. It is envisaged that this arrangement is of particular use when the drill head is approaching existing plant which generates an electromagnetic field and which lies adjacent to the path of the drill head and so the path of the duct forming apparatus can be changed to avoid the plant and prevent damage to the same. Typically there is provided apparatus for forming a duct wherein the electromagnetic field sensor is positioned on or adjacent to the outer surface of the drill head, and detects the field gradient at that position, and thus the distance of the drill head from the guidance plant, using the equation D2=V2n.S/(V2p-V2n) where V2p is a first field reading from a first position of the sensor, V2n is a second field reading from a second, rotated, position of the sensor and D2 is the distance between the centre of the guidance plant and the outer surface of the drill head. In a further embodiment of the invention the drill head is provided with a sensor to detect the rotational angle of the drill head relative to a linear plane, typically the vertical plane. Typically a conventional roll angle sensor is provided in the drill head. Typically the signal impressed into the guidance plant is an alternating electric current and, if access can be gained to the guidance plant then the current can be injected by direct connection of a current generator to the plant or, alternatively, by inducing a current in the cable using a torroidal transformer placed over the plant. If no access can be gained to the plant then the current can be induced using a remote transmitter placed on the surface. Furthermore it is known that some existing plant already generates an electromagnetic field and if this is the case then the plant can be detected without impression of electrical current. This also ensures that this plant can be detected even if it is not being used to continually guide the drill head but is an obstacle to the path of the drill head. The alternating electric current of a single frequency or plurality of multiple frequencies provided to the guidance plant can be of any value as required but typically in the range of 0.1 Hz to over 100 KHz and the current introduced into the plant generates an alternating magnetic field which radiates from the plant. Typically the drill head includes an angled face which acts as a steering face of the drill. Preferably the detector means on the drill head includes at least two, solenoidal, coils and they are connected to suitable electronic filters and amplifiers to detect the magnetic field and processing means and software to allow the processing and interpretation of the signals to provide the data to the operator for continued guidance of the drill head. In a further aspect of the invention there is provided apparatus for measuring and guiding the position of an article, said article including a detector means including at least one electromagnetic field sensor mounted in an offset position with respect to the centre of the article, to allow detection and monitoring of an electromagnetic field, and a means to rotate the electromagnetic field sensor about the centre of the article. Typically the apparatus can include any of the features as herein described with regard to the apparatus for forming the ducts or passageways such as further electromagnetic field sensors and/or roll angle sensors. In one embodiment the apparatus is provided not on a drill head for forming the duct or passageway but on an article for movement along a previously formed existing duct or passageway and to allow the position of the duct or passageway to be determined with reference to adjacent plant generating an electromagnetic field and operating the guidance apparatus as previously described. In a further aspect of the invention there is provided a method for creating a duct, said method comprising the steps of positioning a drill head including at least a first electromagnetic field sensor mounted therein for indicating the distance of the drill head from other plant by detecting the electromagnetic field generated from said other plant, advancing the drill to form the duct and rotating the electromagnetic field sensor to generate a series of signals indicative of the electromagnetic field strength to allow the positioning of the drill head to be determined with reference to the said other plant. Typically the sensor is rotated along with the drill head during formation of the duct, either continuously or, alternatively the sensor is rotated at intervals through at least one half revolution. In one embodiment the said other plant is existing plant which is already in position and with respect to which the path of the drill head is determined. In another embodiment the said other plant is existing plant which represent an obstacle to the path of the duct and the presence and position of which is required to be detected to allow the path of the drill head to be controlled to avoid the same. In a further embodiment the said other plant is a length of cable or wire or other material laid on the surface and which acts as a reference guide for the drill head. Typically the electromagnetic field sensors used in the method are electromagnetic coils and are hereinafter referred to as coils. In a first embodiment the coil is provided with its longitudinal or sensitive axis lying substantially perpendicular to the longitudinal axis, of the drill head. In one embodiment the drill is moved to a start position with the longitudinal axis of the drill parallel to the longitudinal axis of the guidance plant and the sensitive or longitudinal axis of one coil along the longitudinal axis of the drill head is in this arrangement perpendicular to the flux lines which radiate from the guidance plant magnetic field. In this orientation the output signal from the coil is a minimum or null. The output signals received from the offset and rotated coil is dependent on the orientation of the longitudinal axis of the drill relative to the cable and also on the rotational orientation of the drill. The maximum output from the coil is obtained when the drill head is rotated so that the sensitive or longitudinal axis of the coil is perpendicular to the plane of the guidance plant and the drill. The minimum output signal from the coil is obtained when the sensitive axis of the coil is parallel to the plane of the drill and the guidance cable. As the drill is rotated further the output from the coil produces a maximum negative output and then a zero output following a sinusoidal pattern. Thus, the apparatus and method of the invention can be used to advantage in several ways such as for forming ducts for the installation of new plant in groups between manholes in order to minimise the usage of cable and to use existing rights of way. Indeed the plant can be dragged along by the drill apparatus as the duct is formed. If the new plant is laid within a specified and controlled distance from the existing plant then it should not be necessary to negotiate new rights of way A further use is for the automatic guidance of the drill parallel to and below a single cable laid on the surface. The cable is laid on the ground surface along the proposed route of the drill and the drill head can be directed using the sensor system described herein. A further use is for the installation of new plant in close proximity to high value plant such as fibre optic data cables or hazardous electrical cables or pipes containing hazardous fluids. The apparatus provides a means of drilling in close proximity and guiding the drill to prevent the drill damaging the existing cables. In can therefore be referred to as a cable avoidance system. An electromagnetic signal is injected into the cable to be protected or the cable may already generate an electromagnetic field and the apparatus for guiding the drill is able to continuously measure the separation of the drill from the cable and also provide information on the orientation of the drill relative to the cable. The position of the drill relative to the cable can therefore be continuously monitored and the drill steered to maintain safe distance. Specific embodiments of the invention will now be described with reference to the accompanying drawings wherein: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a guidance plant in the form of a cable and associated magnetic field; FIG. 2 illustrates a first embodiment of the invention showing the drill head in conjunction with the guidance plant; FIG. 3 illustrates the drill head of FIG. 2 in a moved position; FIG. 4 illustrates the drill head of FIG. 2 in a further position; FIG. 5 illustrates schematically the positions and signals generated by the first coil relative to the guidance cable; FIG. 6 illustrates the output signals received from the second and third coils of the drill head of FIG. 2; FIG. 7 illustrates the position of a second coil relative to the guidance cable; FIG. 8 illustrates in schematic form various positions and signals generated by the second and/or third coils relative to the guidance plant; FIG. 9 illustrates a further position of the second coil relative to the guidance plant; FIG. 10 illustrates a further position of the coil relative to the guidance plant; FIG. 11 illustrates the drill head in a position relative to the guidance plant in a perspective view; FIGS. 12A to F illustrate in schematic form various positions of the drill relative to the guidance plant; and FIG. 13 illustrates a second embodiment of the drill head of the invention having a first and second coil. DETAILED DESCRIPTION OF THE INVENTION Referring firstly to FIG. 1 there is illustrated a guidance plant 2 and, in this embodiment, the guidance plant is a cable which has previously been laid in existing ducts in the ground. An alternating electric current is injected into the cable 2 and the current is flowing along the cable 2 generates an alternating magnetic field indicated by the letter B which radiates outwardly from the cable and along the length thereof. Thus, this guidance cable is activated to act as a guide for reference for a drill which is to be used to form a duct running parallel to the said guidance cable 2 at an offset distance therefrom. In a first, but not the preferred, embodiment, the drill 4, which is shown in end elevation in FIG. 2, is provided with three electromagnetic field sensors in the form of electromagnetic coils 6 mounted with its sensitive or longitudinal axis 8 along the longitudinal axis of the drill centre and coils 10 and 12 which have their sensitive longitudinal axis 14 perpendicular to and offset from the sensitive axis of the first coil 6. The coils 10 and 12 are mounted adjacent the external side 16 of the drill at diametrically opposed positions. To set the drill in the required starting position, the same is positioned at the required offset distance from the guidance cable 2 and at the required depth from the surface of the ground 20. When the longitudinal axis of the drill 4 is in this parallel position with the guidance cable 2, the sensitive axis 8 of the coil 6 is perpendicular to the flux lines 22 of the magnetic field B as shown in FIG. 1. In this position the output signal received from the coil 6 is at its minimum or a null. If the drill changes direction but in the plane 24 defined between the guidance cable 2 and the centre of the drill 4, such as shown in FIG. 3, then the sensitive axis 8 of the coil 6 remains in its perpendicular position to the flux lines 22 and thus the output signal received from the coil remains in its minimum or a null value. However, if the drill changes direction and if this change of direction moves the drill out of the plane 24 such that the length of the drill no longer lies in the plane 24 in end elevation, such movement shown in FIG. 4, then the coil 6 intersects a flux line 22 of the magnetic field and the output signal from the coil 6 will increase, Thus it will be clear that the output signal from the coil 6 only changes in response to changes in the direction of the drill which moves the longitudinal axis of the drill out of the plane 24 as illustrated in FIG. 4. The direction and extent of movement of the drill outwith the plane 24 is detected by comparing the output signal received from the coil 6 to the electrical current value applied to the guidance cable 2. As both the signal received and the electric current are time varying sinusoids, the time relationship between the two, i.e. the phase difference, can be analysed and this allows the direction and plane of the sensitive or longitudinal axis 8 of the coil 6 in the magnetic field B to be determined. FIG. 5 illustrates in diagrammatic form the manner in which the coil 6 position relative to the guidance cable 2 can have an effect on the output signal received. In position A the output from the coil is a sinusoid and, when compared to the wave form of the electric current supplied to the guidance cable 2, it can be seen that the output 26 from coil 6 is in phase with the wave form 28 of the electric current supplied to the guidance cable 2. In position B the output 30 from coil 6 is zero as no flux lines are being cut as the drill lies in the same plane in this position. In position C the coil 6 has effectively reversed its orientation such that the sensitive axis 8 and hence drill 4 is now pointing away from the guidance cable 2 and thus the output 32 from coil 6 is a sinusoid form which is 180 degrees out of phase with the signal 28. Thus, the position of the sensitive axis 8 of the coil 6 and hence the longitudinal axis of the drill 4 can be determined by comparison of the output signal 26, 30, 32, or any other output signal received, with the wave form and signal 28 of the guidance cable 2. The orientation of the longitudinal axis of the drill 4 relative to the guidance cable 2 and also the rotational orientation of the drill 4 relative to the plane containing the guidance cable and drill can be determined by analysing output signals received of the coils 10 and 12 of the drill. The maximum output from the coils 10 and 12 is obtained when the drill is positioned such that the sensitive axis 14 as shown in FIG. 2 of the coils 10 and 12 is perpendicular to the plane 24 between the drill and guidance cable as shown in FIG. 2 and as illustrated in position A of FIG. 6. The minimum output from the coils 10 and 12 is obtained when the sensitive axis 14 of the same are parallel to the plane 24 as illustrated in position B of FIG. 6 and, if the drill is rotated further, then a maximum negative output signal is received as indicated in position C and a further zero output signal is received at the position shown D. It should be appreciated that a preferred embodiment is to only use one of the coils 10, 12, say coil 10, as this can be rotated to provide the required data. When the drill is in a rotational position which gives a maximum output as indicated at positions A and C of FIG. 6, changes in direction of the longitudinal axis of the drill 4 in the plane 24 as indicated in FIG. 7 will produce no change in the output from the coil 10 as the drill is rotating. However, changes in direction of the longitudinal axis of the drill 4 out of the plane 24 produces a decrease in output signal received as indicated in FIG. 8, with FIGS. 7 and 8 illustrating the coil 10 only for illustrative purposes. FIG. 8 illustrates the difference in the signal amplitude which occurs when, for example, sensitive axis 14 of coil 10 deviates by 10 degrees from the perpendicular position shown at the position B of FIG. 7. FIG. 9 illustrates the drill 4 in a position where the direction of the same has changed but in the same plane as plane 24 such that the reading from the coil 6 will not alter and, as the rotation is about axis 30, which is perpendicular to the axis 14 of the coil 10, the coil 10 will not be sensitive to orientation changes in or out of the plane. In FIG. 10, the coil 10 is rotated about its sensitive axis 14 but with the coil 10 in the parallel plane to the plane 24 and thus, the output signal for the coil 10 is zero with reference to position B of FIG. 6 and as the position of the same does not change relative to the plane 24 no change in signal output will occur but the actual change of the drill 4 upon rotation will be sensed by the change of signal received from the coil 6 with reference to FIG. 4, as the drill moves out of the plane 24. Thus, if the coil 10 is positioned in the drill 4 with the sensitive axis 14 aligned parallel to the steering face 32 of the drill 4 as shown in FIG. 11, then by rotating the drill 4 and observing output from the coil 10 when rotated until they reach a maximum value, it is possible to orientate the coil 10 and hence the steering face 32 to lie with their planes and plane movement 34 respectively, perpendicular to the plane 24. The drill is now pushed forward without rotation and steering corrections can be made to change the direction of the drill perpendicular to the plane 24. Thus if the output from coil 6 indicates a change in output from the minimum i.e. a deviation out of the plane 24 then a steering correction can be made by rotating the drill until a maximum is obtained from the coils 10 and 12 and, if the rotation is then stopped at this position the drill can then be pushed forwards to direct the drill 4 back towards the plane 24. The positioning is dependent upon the starting position of the drill 4 relative to the guidance cable 2 such that it can be above, below, to the side or any position offset from the guidance cable throughout 360 degrees thereof. The plane 24 as shown in FIG. 12a and 12b can be at any rotational angle R to the horizontal plane and coil 6 is provided to measure deviations from this initial orientation. However, the drill 4 can be subjected to perturbations due to changes in ground conditions as the drill passes therealong and these perturbations can cause the drill 4 to deviate from the plane 24 by an angle S as indicated in FIGS. 12c and 12d. With the output signal received from coil 6, and comparison of this with the input signal 28 to the guidance cable 2, the deviation between the signals can be detected and, in conjunction with the output signals received from the coil 10, the drill 4 can then be rotated until the steering face 32 is pointed in the correct direction such that when the drill is moved in that direction, the deviation will be corrected and the angle S of deviation will be reduced to zero as shown in FIG. 12e wherein the drill 4 now lies in a plane 34 which is parallel to plane 24 and guidance cable 2. The steering mechanism thus described can bring the drill 4 back into line with the guidance cable 2 but it may be at a different rotational angle R' as indicated in FIG. 12f in comparison to the rotational angle R in FIG. 12b. To return the drill to the original rotational angle R, a roll angle sensor can be provided on the drill which measures the roll angle of the drill relative to the vertical plane. Information from one of these sensors, when combined with the information from coils 10 can be used to return the drill to the original rotational angle R in the following manner, whereby if the drill is rotated whilst in the original position, the maximum output from coil 10 is obtained when the roll angle of the drill is at 360-R degrees such as that shown in FIG. 12b. If the drill is rotated whilst in the second position as shown in FIG. 12f, the maximum output from the coil 10 is obtained when the roll angle of the drill is at 360-R' degrees and thus the roll angle at which the maximum value occurs indicates the rotational position of the drill 4 relative to the guidance cable 2. The steering system can then be used to return the drill back to the first position as shown in FIG. 12a by stopping rotation of the drill when the maximum value is reached and pushing forward the drill to bring the same into the required plane. In addition to deviations of the drill out of the plane 24, the system is capable of measuring and correcting for deviations in the position of the drill in the plane 24. Because of the shape of the magnetic field B around the guidance cable 2 it is not possible to use the coil 6 to measure angular deviations of the drill 4 in the plane 24 but, by using the coils 10,12 it is possible to measure the distance from the drill 4 to guidance cable 2 by, in one embodiment rotating the drill to the roll angle where a maximum positive output signal is received from the coil 10 and a maximum negative output signal is received from coil 12 comparing the signals to generate a distance value from the guidance plant and then rotating the drill until a maximum negative output signal is received from coil 10 and maximum positive output signal is received from coil 12 and comparing and so on as the drill head progresses. The output signals from the coils 10,12 are proportional to the current in the guidance cable and inversely proportional to the distance from the cable, i.e. V2=K.i/D2 or K.i=V2.D2 V3-K.i/D3 or K.i=V3.D3 therefore V2 D2-V3D3 or D2=V3.D3/V2 but D3=D2+S therefore D2=V3/V2.(D2+S) D2=V3/D2/V2+V3.S/V2 D2(1-V3/V2)=V3/S/V2 D2=V3.S/V2.1/(1-V3/V2) D2=V3.S/(V2-V3) Where i=current D2=distance of coil 10,12 closest to guidance plant D3=distance of coil 10,12 furthest from guidance plant V2=reading from coil 10,12 closest to guidance plant V3=reading from coil 10,12 furthest from guidance plant S=distance between coils 10,12 and therefore a deviation in the drill 4 which results in D2 reducing can be corrected by rotating the drill until the output from coil 10 is a minimum and the face 32 of the drill is pointing towards the guidance cable 2. The rotation is then stopped and the drill 4 is pushed forward in the required direction for a short distance and then rotated again to obtain an estimate of the new distance of the drill from the cable 2. An alternative and preferred arrangement of electromagnetic field sensors or coils is shown in FIG. 13, where a coil 106 is provided on drill 104 wherein the coil 106 is provided with its sensitive axis 108 along the longitudinal axis of the drill 104 which lies on a plane 124 defined between a guidance cable 102 and the centre of the drill, in end elevation. A coil 110 is positioned offset from the centre of the drill as shown and in this case on the outer surface of the drill with its sensitive axis 114 perpendicular to the longitudinal axis of the drill head. Coil 106 is used as described before with reference to coil 6 to measure the deviation of the drill 4 out of the plane 124 and coil 110 is used to measure the relative and rotational position of the drill head 104 with respect to the guidance cable 102. The distance of the drill head 104 from the cable 102 is measured using only coil 110 rather than in the previous embodiment where two coils were used. This is achieved by rotating the position of the coil 110, typically by rotating the drill head, and measuring the difference between the output signals from coil 110. When coil 110 is on the side of the drill 104 nearest to cable 102 as shown, the coil is positioned so that output from the coil will have a maximum positive value V2p and, when the coil 110 is on the side of the drill away from the cable as shown in broken lines 110', it is positioned so that the output has a maximum negative value V2n. As there is a greater distance between the coil 110 when in the position 110' on the drill 104 from the guide cable 102, the value for V2n is less than V2p and thus, the distance D2 of the drill 104 from the cable 102 is given by the expression: D2=V2n.S/(V2p-V2n) This embodiment has the advantage that it is not necessary for the two coils 10,12 to be used and the same to be matched and calibrated as is the case with the first embodiment wherein matching and calibration is necessary to measure the small differences across the diameter of the drill and the changes in coil parameters which can occur due to temperature and vibration. A single coil thus reduces the work needed to set the same up for use and the possible errors which can occur due to temperature and vibration are reduced. Furthermore the space requirements for use of two coils as opposed to three coils and the associated control equipment is significantly less. The coils located in the drill are used to detect the magnetic field radiated from the guidance cable. The coils used are solenoidal coils and by the selection of the coil orientations and positions it is possible to measure the distance of the drill from the guidance plant and the orientation of the drill relative to the longitudinal axis of the guidance plant and by the use of conventional rotational angle sensors to measure the roll angle of the drill head relative to the vertical plane, in combination with the coils, it is possible to measure the position in the ground of the drill such that the duct formed thereby can be predicted and controlled to be substantially parallel and offset from the guidance cable and thus, a non-intrusive or trenchless duct forming process is provided by the present invention. In order to install clusters of ducts for cables, it is suggested that the drill used needs to produce a bore at a nominal separation distance of for example 300 mm from the existing plant with a maximum deviation of plus or minus 100 mm in the bore. The accuracy required is achieved by using the location system described herein which continuously detects the position of the existing guidance cable using the detector in the head of the drill and provides the information for either manual or automatic steering adjustment. Information from the detector means in the form of output signals are processed directly in the drill chuck to control a steering mechanism in the drill or the information can be passed to the drill operator at the surface where it can be displayed for manual control or to a microprocessor for a computer for automatic control of the drill and in each case, the output signal received from the detector means can then be compared to the input signal along the guidance cable, and so the control of movement of the drill can be achieved.
The apparatus and method of the invention relates to the formation of ducts or passageways, referred to as ducts underground by using existing lengths of plant such as pipes, cables or wires, or a length of plant laid in predetermined position as a guidance or reference for the drill head used to form the duct or passageway as it passes through the ground. The plant is used to generate an electromagnetic field which is sensed by at least one electromagnetic field sensor mounted in the drill head, said sensor rotated to allow comparison of signals and the distance of the drill head from the plant to be calculated. Other sensors can also be provided to determine other positional characteristics of the drill head with respect to the plant. This allows the duct to be formed with the avoidance of potentially hazardous plant and/or along a path which is determined with reference to the plant. The apparatus can also be used as a guidance means without the drill to pass along existing passageways and indicate the path of the same using the same operating procedure.
4
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority to U.S. Provisional Patent Application 61/849,277 entitled Sound Deadening Board filed on Jan. 23 2013, the content of which is hereby incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present disclosure relates generally to affecting sound within a space by absorbing, controlling, and/or isolating the reflection of sound. More particularly, the present disclosure relates to a sound control system for covering surfaces within a space to control and/or reduce the sound within the space and/or the sound transfer between spaces. Still more particularly, the present disclosure relates to a system of sound deadening boards, which may perform multiple functions, including sound control, sound absorption and/or sound isolation. BACKGROUND [0003] In an increasingly noisy and close-quarters world, sound diffusion and leakage from room to room or unit to unit is becoming an increasingly pressing issue in terms of enjoyment of peace and quiet in one's abode, place of work, etc. Separately, within a particular room, especially a large room, various surfaces can reflect too much sound, creating a live, reverberant environment, making conversation difficult and making sound quality suffer in general. [0004] To combat these issues, sound tiles, thicker walls and extra layering in construction have been used with varying levels of success. Various technical measurements, such as STC (Sound Transmission Class) can be employed to give a simple representation via a single number such as “54” to represent how much a particular partition in a building prevents noise from reaching the adjacent room. A higher number represents a greater sound dissipation, and the example of 54 would mean that a substantial amount of sound would be blocked, but a significant portion would transmit through the medium. Generally dBA (decibels acoustic) or SPL (sound pressure level) is used to represent the efficacy of various discrete strata within the audible-to-human portion of the sound spectrum. [0005] Sound control devices have long been used in music rooms, such as recording studios and band and orchestra rooms at various educational institutions to combat the issue of unwanted reverberation and noise within a particular room. More recently, these technologies have also seen use in home theater, music rooms and general household living rooms, with the goal of improving sound quality, without necessarily having the goal of preventing sound leakage into the adjacent room or rooms. For devices used to absorb sound, not isolate it, a Sound Absorption Coefficient is generally given, with different ratios from 0.0 to 1.0 for various segments of the audible spectrum, roughly corresponding to ranges like the human voice, to lower ranges, as would befit a home theater with a powerful sub-bass range response. A value of 1.0 being the highest and denoting total sound absorption for a given device, i.e., sound waves that hit the device do not reflect back once they have touched the device. [0006] Typically, however, unless a building is built with the intent of including sound control or isolation, the costs involved in retrofit are prohibitive for most consumers. When a building is built with these features, the walls or floors will generally be thicker, denser or more expensive than a typical house or other building would have. Alternative to initially building the room to control sound is the option of adding tiles, boards or other external insulation to existing structure. Tiles and materials sold have generally been made from highly synthetic materials and have been rather expensive and/or unsightly, especially in terms of inexpensive or home use. Furthermore, the existing external solutions to the problem have been relatively heavy, requiring strong adhesives or fasteners in order to keep the devices attached to the walls, and this can lead to unsightly fasteners being visible externally. [0007] The aesthetic element is especially critical because many currently-offered after-the-fact (after a particular room or building has been constructed and finished) solutions to these sound issues have unusual or unsightly appearances in rooms that often tend to be used for entertaining visitors or other guests who may be surprised to find odd-looking objects affixed to the walls or ceiling, oftentimes at odd angles and colored and textured differently than the rest of the room. SUMMARY [0008] In one embodiment there is disclosed a sustainable, linear sound deadening board, which can be mounted to interior walls, ceilings, etc. of a room, comprising an outer surface, an inner surface, an upper end, a lower end, a left end, and a right end of the board; an interlocking mechanism allowing the board to interface with other replications of identical boards on either side of the board; a plurality of layers; wherein the layers comprise cellulose or other post-consumer or biodegradable material. A tongue and groove design is utilized in preferred embodiments by offsetting layers below the tongue, allowing one board to couple to other similar boards on either side. Other interlocking mechanisms can also be utilized, such as a finger interlocking mechanism or shipped lapped joints. The board comprises a plurality of layers, generally alternating the directionality of grain at 90-degree rotations or substantially perpendicularly, with such layers composed of cellulose, other sustainable, biodegradable, or re-used material. [0009] In another embodiment, A sustainable sound deadening board is disclosed, comprising a plurality of layers in sandwich-like construction including a bottom layer, an intermediate layer on top of the bottom layer and a top layer on top of the intermediate layer, each layer being of a selectable material particularly adapted to affect sound, wherein the intermediate layer is shifted horizontally relative to the bottom layer creating a tongue and groove affect. [0010] The board has lightweight construction, permitting easy fastening of the board to various surfaces, such as a wall or ceiling in a room of a dwelling, commercial building, or industrial building. Lightweight construction also reduces the cost of manufacturing and solves other problems typically associated with the machining or milling of the interlocking joints. This board also allows more ease in installation by minimizing the cuts required by the installer. The interlocking joint created by offsetting layers integral to the ends of the invention allow for the installer to cut only once at the beginning and end of each row. No back cutting or bevel cuts are required to join each piece. [0011] The board can be covered with various materials, including cloth, paper, vinyl, metal or other material used to finish the surface of the board that is visible from inside the room, thus giving a more attractive appearance to that board. The layers of cellulose, cardboard or other sustainable material can be, for example, corrugated cardboard or similar products. By using such materials on the outside of the board only, a more affordable product is created. [0012] The board's layers of cellulose, cardboard, sustainable material, or synthetic material can be of varying thicknesses and numbers of layers, thus giving the board more widespread and advantageous sound properties. By varying the thickness of each board or set of boards, the product can utilize available retrofit products of common thickness. For example, the board may be applied to an existing wall or ceiling and common extensions may be added to the existing electrical boxes. Likewise, the layers of cellulose or other sustainable material can be of varying densities or arrangements, further enhancing the efficacy of the board. [0013] This board provides a single-product solution to an ongoing problem experienced by many users, both residentially and professionally, of effectively and cost-effectively deadening the sound in a room and sound leaking from a room and purchasing an environmentally friendlier product and customizable product unlike many products currently on the market. The clever design of an example embodiment utilizes a novel approach to linking various boards, while also hiding the fasteners, such as staples or nails, holding the boards to the edges and walls of a room, or other surface, such as a ceiling. BRIEF DESCRIPTION OF THE DRAWINGS [0014] These as well as other objects and advantages of this sound deadening board will be more completely understood and appreciated by referring to the following more detailed description of embodiments in conjunction with the accompanying drawings of which: [0015] FIG. 1 is a top view of a system of adjacent sound-deadening boards. [0016] FIG. 2 is a top perspective view of a layered sound-deadening board of the system of FIG. 1 . [0017] FIG. 3 is an exploded cross-sectional view of a sound-deadening board of the system of FIG. 1 . [0018] FIG. 4 is a top view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned. [0019] FIG. 5 is a side view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned. [0020] FIG. 6A is a side view of two adjacent sound deadening boards of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned. [0021] FIG. 6B is a bottom view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned. [0022] FIG. 7 is a top view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned. [0023] FIG. 8 is a perspective view of two adjacent sound deadening boards. [0024] FIG. 9 is a side view of two adjacent sound deadening boards. [0025] Although the subject matter is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the invention is to cover all modifications, equivalents, and alternatives. DESCRIPTION [0026] The present disclosure, in some embodiments, relates to a system of sound deadening and/or absorbing boards that may be placed on surfaces such as walls or ceilings within a space to control the sound therein. The boards may be generally elongate boards and when assembled into a system may provide a pleasantly aesthetic system with a series of parallel extending elongate elements. This may be in contrast to other known sound control systems that are more patchy and aesthetically obtrusive. The boards may be of layered construction allowing the overall effect on sound to be customizable based on the selection of the material used in the several layers. In addition, the assembly of the boards into a system may allow them to interlock to form a larger array of boards having a unified appearance and allowing for large expansive systems to be installed, while avoiding warpage or other out-of-plane distortion. [0027] Referring now to FIG. 1 , a sound control system is shown. The system may include an assembly of sound control elements such as sound deadening boards. The sound control elements may be arranged in a generally rectangular-like array where the several elements are extending generally parallel to one another and are placed end-to-end as well as adjacent to other elements in the array. The end-to-end placement and adjacent placement may include an interlocking or other substantially tight fit allowing for the assembly to appear as a unified or at least assembled series of elements. The system may be sized, shaped, placed, and oriented on a surface and configured to affect the sound within the space. It is to be appreciated that considerations may be given to aesthetics, durability, finish, and other factors when considering how to select the size, shape, placement, and orientation of the system. [0028] In one example, the sound control system can be used in an educational band room where the system is configured to control sound created from a variety of instruments at unpredictable volume levels. In the same example, the system may be configured to isolate and absorb as much sound as possible to prevent noise leakage and diffusion to other unwanted quarters. In another example, the sound control system may be used in a home or commercial theater setting where volume levels are generally more predictable. In the theater system example, preventing sound leakage into the adjacent room or rooms may or may not a primary goal of the sound control system. However, the sound control system may be configured and designed for improving the sound output quality for audiences. [0029] In some embodiments, the system may be used to cover all or substantially all of a wall or ceiling. In other embodiments, a lesser portion of the wall or ceiling may be covered and one or more panels of the system may be used to affect the sound in the space. The elongate nature of the system may allow for plank-like, or slat-like sections of the system to be installed to affect aesthetics together with sound. In other embodiments, other geometrical shapes may be included. In some embodiments, a rectangular or angled orientation of a panel may be used. In other embodiments, the panel or panels may be in a parallel plane adjacent a wall or ceiling or the panel may be tipped relative to the wall and out of plane with the wall. The panels may be placed high or low or at intermediate heights of a wall or along the sides or middle of a ceiling structure. Still other sizes, shapes, locations, and orientations may be used. [0030] As shown, in some embodiments, the system may include an assembly of sound control elements where a large portion of the elements are substantially the same or even identical. In some embodiments, all of the elements in a system may be substantially the same and in other embodiments, all of the elements in a system may be substantially the same except for end or edge elements that may be cut to fit or to affect the size or shape of the system. Given the similar nature of the several elements used to make up the system, the remaining portion of the specification may focus on a particular element of the system. [0031] As shown in FIG. 2 , a perspective view of a sound control element is shown. The sound control element may include a plurality of layers including a bottom layer, an intermediate layer, a top layer, and a finish layer. The plurality of layers of the sound control system may be constructed from materials of varying source, density and thickness. The sound control element may be configured to affect sound when sound waves are imparted thereon. Moreover, the element may be configured to be assembled in a sound control system such as the ones described above. The particular layers may be selected to affect sound in a particular way and some of the layers may be different than other layers or all of the layers may be the same or similar material. In some embodiments, some layers may be adapted to allow sound through in one direction, but resistant to allowing sound travel the opposite direction when some sound waves are reflected back in the direction of the source. Lower layers may be sound absorbing layers, for example. Still other arrangements of layers may be provided. [0032] Each sound-deadening board is assembled to sit on top of, below, or on the side of a same or similar sound-deadening board. By using boards that are roughly the same depth, a linear effect is created when a series of elongated boards of similar material are assembled together. The linear effect of the board is also exemplified when the adjacent boards connect as so to not expose any part of the wall or mounting base. [0033] As shown in FIG. 3 , an outermost layer 400 may be provided and may wrap around the outside of a single-sound deadening board, which can be selected from a cloth, paper, vinyl, metal or other material. The covering portion may be selected to address issues of aesthetics, sound, and other factors. The covering portion may be arranged relatively taut across the backing or top layer and may be secured to the backing or top layer with adhesive. In some embodiments, the covering portion may be secured to an underside of the top or backing layer with adhesive, staples, or other securing systems. Still other securing systems or devices may be used. [0034] In addition, a top horizontal or backing layer 100 may be included as one of the three horizontal layers that comprise the sound-deadening board. Any given layer of the sound control system may be constructed of multiple plies. For example, referring now to FIG. 3 , a top horizontal layer 100 and a bottom horizontal layer 300 are both comprised of double ply layers. The top layer 100 may be positioned to sit above a middle horizontal layer 200 in each sound-deadening board. The top horizontal layer 100 of each sound-deadening board may be the layer that becomes exposed on the mounting surface. The top layer 100 may include a portion with flutes extending in the long direction in addition to a portion with flutes extending in the short direction. Thus, it may be desirable to wrap this top horizontal layer 100 with a covering portion 400 both to create a good aesthetic, but also close off areas where the flutes may be exposed as shown in FIG. 2 . [0035] The top or backing layer 100 may include chamfered edges 500 , extending along the length of the layer and may also include chamfered edges on the ends of the layer 600 . The top view of the system as shown in FIG. 1 reflects a pleasant aesthetic due to the chamfered edges 500 , 600 . In other embodiments, the chamfer may be omitted and a more rectangular profile may be provided. [0036] As shown in FIG. 2 , the top horizontal layer 100 also includes a portion with flutes extending along the length of the board 700 and along the width of the board 700 . Any given layer may be made up of one or more sub-layers of material with same or differing grain orientations from other surrounding layers of the sound control system. Differing grain orientations allow for an elongated assembly of the boards because the varying grain (i.e., the flutes) allow the particular layer to resist bending or warpage in multiple directions. [0037] Referring now to FIG. 3 , a middle horizontal layer 200 may be oriented to sit between the top horizontal layer 100 and a bottom horizontal layer 300 . The middle horizontal layer 200 may be offset horizontally from the top layer 100 and the bottom horizontal layer 300 . This offsetting of layers may create a tongue and groove effect. The tongue and groove effect may allow for a continuous network of the sound-deadening boards, allowing them to interlock with each other in a seamless fashion. The bottom horizontal layer 300 may be oriented to sit adjacent to the mounting base or wall that the sound deadening board is fixated or secured to. [0038] Referring now to FIGS. 4 and 5 , in one embodiment, the top horizontal layer 100 and the bottom horizontal layer 300 may not be vertically aligned with each other in one or more directions. In this embodiment, on the tongue side/end of the board the bottom horizontal layer 300 may extend more horizontally outward than the top horizontal layer 100 to help support a relatively flexible tongue. This embodiment may be useful for sound deadening board arrangements wherein the middle horizontal layer 200 is made from a more flexible material. The extension of the bottom horizontal layer 300 thus acts as a support to the middle horizontal layer 200 by supporting a portion of the length that extends outward from the middle horizontal layer 200 . Where the tongue portion of the board is used for placement of a fastener, the extending bottom layer 300 may support the inner portion of the tongue during placement of fasteners through this inner portion of the tongue. [0039] In one embodiment, a fastener 800 is inserted through a tongue on a middle horizontal layer 200 at an angle near the base of the tongue before another board is placed adjacent to this board. An opposite side of the adjacent piece, which may be a tongue from a middle horizontal layer, is fastened by repeating this fastening approach. This process pins the adjacent board to the first board. The ability of the board to hide a fastening device 800 in an adjacent board, paired with the covering material 400 of the boards, leads to an aesthetically pleasing appearance of the boards, belying the true, logical and inexpensive nature of the underlying apparatus and board. [0040] The array of horizontal layers allows customizability of the sound deadening board. Each layer of the system can be made from the same or different material, allowing users to construct their system from a mix of cellulose or other post-consumer or biodegradable material. The ability of each layer to be made from different material also allows a variety of combinations of different layers to be used for specific, particular purposes. For example, referring to FIG. 8 , in one embodiment, the top horizontal layer 100 may be constructed from different material than the bottom horizontal layer 300 . In another embodiment, all three horizontal layers may be made from the same post-consumer, biodegradable or synthetic material but the wrap material 400 may be a different material than the horizontal layers. [0041] The tongue and groove aspect of the board is just one example of an interlocking mechanism that may be used to connect adjacent boards. In one embodiment, multiple tongues protrude from a single board and are able to interlock with adjacent grooves. In another embodiment, a ship lapped or finger interlocking mechanism may be utilized to interlock adjacent boards. [0042] Referring now to FIG. 8 , two replications of an embodiment of the device is shown. In this embodiment, the top horizontal layer 102 is vertically aligned with the bottom horizontal layer 302 of the embodiment. In this embodiment, the bottom horizontal layer 302 does not extend to support the tongue of the embodiment which, in this example, is the middle horizontal layer 202 . In this embodiment, the tongue of the interlock system may be made from a stronger material that is able to support itself during the interlocking process because of the lack of support from an unextended bottom horizontal layer 302 . [0043] Referring now to FIG. 9 , a side view of two adjacent sound-deadening boards is shown. In yet another embodiment, a middle horizontal layer 202 , acting as a tongue in an interlocking mechanism, may not be supported by a bottom horizontal layer 302 . In this embodiment, the top horizontal layer 102 is vertically aligned with a bottom horizontal layer 302 . [0044] Persons of ordinary skill in the relevant arts will recognize that the subject matter may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the subject matter may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art, and are within the scope of the following claims.
A sustainable linear sound-deadening board with a tongue and groove design, which allows multiple boards to connect linearly and giving a both clean and attractive appearance. The board is effective in reducing reverberation within a room as well as acting to improve the soundproofing aspect of undesired sound leaking from one room to another. The board can be made from reused or biodegradable materials thus creating a device that is both cost-effective and less harmful to the environment.
4
FIELD OF THE INVENTION [0001] The present invention relates generally to a portable heater. More particularly, the present invention relates to a portable heater with a tool box integrated with the heater. BACKGROUND OF THE INVENTION [0002] Often workers who are working on a construction project, such as building a new building, have to work in an environment where the air is not conditioned. For example, when constructing a new home or commercial building, the heating system may not be installed and the environment may be very cold for the workers. One solution to this problem is to bring small portable heaters into the area where the workers are working to provide heat. One problem with some portable heaters is that they may be bulky and hard to move from one space to another. [0003] An additional problem faced by workers, is that they often require using many different tools. While tool belts are one way to permit the workers to easily carry several different tools, some workers may require more tools that can be fit on a tool belt. Workers may have tool boxes in order to store all the tools they may require. Additionally, tool boxes provide a small measure of security to store tools. Additionally, tool boxes provide a means for transporting tools from one place to another. One problem with tool boxes that they may be bulky and heavy thus awkward to move to place to place as workers finish one area and move on to another area. [0004] In addition to heaters and tools, workers may also require lights, latters, and other pieces of equipment in order perform their job. Often when work is finished for the day, at end of a week, or other time period, in order to minimize tools lost to theft or corrosion due being exposed to the elements, workers pack up their equipment and take them with them when they leave the work area. [0005] Because there are so many different pieces of equipment, many which may be heavy, awkward, and bulky, a substantial amount of time is spent moving, packing and unpacking equipment. This time could have been spent working. [0006] Accordingly, it is desirable to provide an apparatus that and method that performs several functions desired by workers. Such an apparatus and method may provide heating to a space, tool storage, and a means of tool transportation in a easy to move and manipulate manner. Such a method or apparatus can reduce the amount of pieces of equipment that need to be moved. SUMMARY OF THE INVENTION [0007] The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus and method is provided that in some embodiments provide tool storage and heat in a portable and easy to move around piece of equipment. By combining both tool boxes and the heater, two large bulky pieces are consolidated into one and by equipping the apparatus with wheels it may be easily manipulated and moved from place to place. [0008] In accordance with one embodiment of the present invention, a portable-heater is provided. The portable heater includes a housing; a heating element encased in the housing; and a tool box comprising part of the housing. [0009] In accordance with another embodiment of the present invention, [0010] a portable heater is provided. The portable heater may include means for housing; means for creating heat encased in the housing means; and means for storing tools comprising part of the housing means. [0011] In accordance with yet another embodiment of the present invention, a method of providing heat and tool storage in a portable unit is provided. The method includes providing a heating element; housing the heating element; and attaching a tool box to the housing thereby creating a unified tool box and heater housing. [0012] There has thus been outlined, rather broadly, certain embodiments of the invention in order 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 of the invention that will be described below and which will form the subject matter of the claims appended hereto. [0013] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is 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. The invention is capable of embodiments in addition to those described and 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. [0014] 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 present invention. 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 present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a perspective view illustrating the portable heater and tool box according one embodiment of the invention. [0016] FIG. 2 is a cutaway side view of the tool box heater of FIG. 1 . [0017] FIG. 3 is a partial view of the mechanism that permits locking of the handle when the handle is extended to an extended position. [0018] FIG. 4 is a perspective view of the portable heater with accessories. DETAILED DESCRIPTION [0019] The invention 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 invention provides a portable heater and tool box combined together into a single unit [0020] FIG. 1 is a perspective view illustrating a portable heater 10 in accordance with the invention. A portable heater 10 has a housing 12 . The housing 12 includes a tool box portion 14 located above a heater portion 16 . The tool box portion 14 and heater portion 16 share a common housing 12 . [0021] In some embodiments of the invention the housing 12 may be metal. In other embodiments the housing 12 may be plastic. The portable heater 10 is equipped with wheels 18 . While only one wheel 18 is shown in the view illustrated in FIG. 1 , a second wheel is provided but is hidden by the heater portion 16 . [0022] Two feet 20 are attached to the housing 12 of the heater portion 16 . The feet 20 permit the portable heater 10 to remain stationary when the heater 10 is left on substantially horizontal surfaces. In other words, if a floor has a minor incline, the heater 10 will not roll as the feet 20 will provide friction between the heater 10 and the floor. [0023] The heater 10 is equipped with a handle 22 . The handle 22 in some embodiments of the invention can be retracted between an extended position as shown in solid lines in FIG. 1 , and retracted position as shown in broken lines in FIG. 1 . In other embodiments in the invention, the handle 22 is fixed and remains in the extended position. [0024] A tool box handle 24 is mounted to the tool box lid 44 via the handle brackets 25 . [0025] Several controls for the heater are mounted on the tool box portion 14 . For example, an on/off switch 26 , thermostat 28 and a warning light and/or reset button 30 are mounted on the tool box portion 14 of the housing 12 . [0026] The on/off switch 26 in some embodiments of the invention may be a simple toggle switch for supplying or denying power to the heating element 40 (see FIG. 2 ). The thermostat 28 in some of the embodiments of the invention and as shown in FIG. 1 , may be a rotating knob that can vary the intensity of heat out put from the heating element 40 (see FIG. 2 ). [0027] The warning light 30 and/or reset button 30 may be illuminated when power is supplied to the heating element 40 (see FIG. 2 ). Some embodiments of the invention may be equipped with a safety device such as a tip switch. [0028] The tip switch will shut off the heating element 40 (see FIG. 2 ), when an undesirable condition is detected such as the heater 10 being tipped at an unacceptable angle. In such instances the tip switch will cut off power to the heating element 40 (see FIG. 2 ). Such embodiments may be equipped with a reset button 30 where an operator can push the reset button 30 , once the undesirable condition has been eliminated and restore power to the heating element 40 (see FIG. 2 ). [0029] in embodiments of the invention where the portable heater 10 is an electric heater, the heater 10 may be equipped with a power inlet 32 . The power inlet 32 may be a high voltage inlet configured to receive a high voltage power line such as a 220 volt line. Also mounting on heater 10 , as shown in FIG. 1 , some embodiments of the invention may also be equipped with power outlets 34 . The power outlets 34 may be protected by outlet covers 36 as illustrated in FIG. 1 . The power outlets 34 may be a standard power outlet delivering household voltage such as 120 voltage. In other embodiments of the invention, the voltages and outlets may be modified to conform with whatever power standards are used in the location where the portable heater 10 will be used. [0030] The examples stated above as the high voltage inlet being 240 and the standard being 120 volts, are merely mentioned as these are standard voltages for the United States. However, other voltages may be used in accordance of the invention. [0031] Located within the housing 10 , are wiring configurations to permit the power outlets 34 to be wired to the power inlet 32 in such a manner as to supply the voltages described above from power inleted to the power inlet 32 . Power obtained from the power inlet 32 in some embodiments of the invention, is also used to supply power to the heating element 40 ( FIG. 40 ). Thus, the power inlet 32 is operably connected to both the heating element 40 (see FIG. 2 ) and the power outlet 34 . In embodiments of the invention where the warning light 30 is illuminated to indicate that power is being supplied to the heater 10 , the warning light 30 is also operatively connected to the power inlet 32 in order to supply the appropriate amount of power to the warning light 30 . [0032] The portable heater 10 is equipped with a grill 38 which protects the heating element 40 (see FIG. 2 ), while at the same time allows air to pass in and out of the housing 12 . [0033] Turning now to FIG. 2 , a cutaway side view of the portable heater 10 is shown. FIG. 2 illustrates the tool box lid 44 in an open position exposing the interior portion 42 of the tool box 14 . The lid 44 secured to the toolbox 14 with a hinge 46 . The hinge 46 may be any suitable hinge capable of securing the lid 44 to the tool box 14 and permitting the lid 44 to be raised and lowered as desired. The tools will be stored in the interior portion 42 of the tool box 14 . [0034] The heater portion 16 of the portable heater 10 includes a heating element 40 . The heating element 40 , as shown in FIG. 2 , is a tubular shaped electric heating element A reflector 39 is configured to provide a conduit for air to flow through the heater 10 and to, in some embodiments, reflect the heat through the grill 38 and out into the environment in which the heater 10 is located. In some embodiments of the invention and as shown FIG. 2 , insulation 41 may be located behind the reflector 39 providing insulation between the heater portion 16 and the tool box portion 14 . The insulation 41 my also be configured to permit the housing 12 to be cool enough as to avoid burning objects that come in contact with the housing 12 . [0035] In embodiments of the invention where the electric heater 10 is a forced air heater, a fan motor 43 and fan 45 are mounted in the heater 10 and configured to cause air to flow through the heater, the electric heating element 40 and through the grill 38 . [0036] The wheel 18 is connected to the heater 10 via an axle 48 . The axle 48 is in turn connected to the heater 10 by a series of brackets 50 . The handle 22 is attached to the portable heater 10 via brackets 51 . The heater 10 may be moved from place to place by a user grasping the handle 22 , pivoting the heater 10 about the axel 48 to lift the feet 20 to no longer be in contact with a floor and then wheeling the heater 10 to a desired location on the wheels 18 . [0037] When the heater 10 is in the desired location, the heater 10 may be rotated about the axle 48 until the feet 20 are again in contact with the floor. The feet 20 may be equipped on their ends with a rubber or plastic cup 53 that provides a skid-resistance surface to help keep the heater 10 in place once the feet 20 are in contact with the floor. The feet 20 are connected to the heater 10 via brackets 54 in some embodiments of the invention. In other embodiments of the invention, the feet 20 may be attached to the heater 10 in any suitable manner. [0038] In the embodiments of the invention where the handle 22 can be in a raised extended position or a lower retracted position as illustrated in FIG. 1 , the raising and lowering of the handle 22 may be accomplished by a telescoping portion of the handle 22 as illustrated in FIG. 3 . FIG. 3 shows a larger diameter portion 58 of the handle tube 22 . A smaller diameter portion 52 of the handle fits inside the larger diameter portion 58 of the handle 22 . The difference in diameter permits the smaller diameter portion 52 to telescope within the larger diameter portion 22 . In order to secure the smaller diameter portion 52 , in a particular place within the larger diameter portion 22 , the small diameter portion 52 is equipped with spring loaded buttons 54 . [0039] The spring loaded buttons 54 , when they are aligned with holes 56 located in the larger diameter portion 58 of the handle 22 , extend through the holes 56 the buttons 54 extending through the holes 56 secure the small diameter portion 52 within the larger diameter portion 58 of the handle 22 . When it is desired to collapse the handle 22 , an operator may push in the spring loaded buttons 54 in through the holes 56 . Once the spring loaded buttons 54 have retreated inside the large diameter portion 58 , the small diameter portion 52 may telescope and move inside the large diameter portion 58 allowing the handle 22 to move to a retracted position. [0040] Other suitable means for allowing the handle 22 to move between an extended and retracted position, may also be done in accordance with the invention. The larger diameter portion 22 may also be equipped with several sets of holes 56 permitting the small diameter portion 52 to be secured within the large diameter portion 58 of the handle 22 at multitude of different positions as selected by a user. [0041] FIG. 4 shows a heater 10 with optional attachments 60 - 66 . A light 60 is mounted to the handle 22 and is plugged into the power outlet 34 . A battery charger 62 is also plugged into the power outlet 34 . The battery charger 62 can charge battery 64 for tools such as a cordless drill 66 or other tools. The power outlets 34 can be used for any other desired attachments in accordance with the invention. Attachments may include but are not limited to fans, blowers, saws, vacuums, drills, radios or any other electric device. [0042] The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention 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 invention.
A portable heater includes a housing, a heating element incased in the housing, and a tool box comprising part of the housing. A method of providing heat and tool storage in a portable unit includes providing a heating element, housing heating element, and attaching a tool box to the housing thereby creating a unified tool box and heater housing.
5
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to Provisional Application Ser. No. 60/700,365, filed Jul. 18, 2005, the contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to apparatus for monitoring respiratory activity, which also can include snoring activity, and more particularly to a reusable pyro/piezo transducer for producing an electrical signal proportional to respiratory airflow and/or vibration due to snoring episodes for subjects undergoing sleep studies. [0004] 2. Discussion of the Prior Art [0005] Applicant's assignee, Dymedix Corporation of Minneapolis, Minnesota, has pioneered the development of improved sensors that are adapted to be attached to the upper lip or throat area of a patient that, during sleep, produces an electrical signal proportional to inspiratory and expiratory airflow and to episodes of snoring. In U.S. Pat. No. 5,311,875, applicant first disclosed such a sensor embodying a polyvinylidene fluoride (PVDF) film as the active element of such a respiration activity sensor. The film has both pyroelectric and piezoelectric properties and, as such, is responsive to both temperature changes and physical vibration, producing an electrical signal output that can be signal processed to effectively separate the temperature change induced signal from the signal due to vibration. [0006] Improvements in the sensor are the subject of U.S. Pat. Nos. 6,894,427, 6,551,256, 6,485,432, 6,491,642 and 6,254,545, the teachings of which are hereby incorporated by reference as if set forth in full herein. [0007] For the most part, the sensor construction described in the aforereferenced patents were intended for single-use application in that they would not hold up to repeated cleaning. More particularly, moisture could permeate the layered construction to compromise the electrical interface between the PVDF film and its connection to an electrical lead. Moreover, the handling during cleaning operations would lead to detachment of the lead's contact with the PVDF film. [0008] It is accordingly a principal object of the present invention to provide a respiratory activity sensor especially constructed so as to be reusable. More particularly, the sensor or transducer of the present invention is designed to be moisture impervious and constructed such that lead wire pull-out is no longer a problem. SUMMARY OF THE INVENTION [0009] In fabricating the sensor of the present invention, a sandwiched construction is employed in which a PVDF film is coated on its opposed major surfaces with a conductive layer and a pair of lead wires having a metal tab attached to the distal ends thereof are positioned on opposite sides of the PVDF film using a carbon-laced adhesive as a conductive bonding agent between the lead wire's metal tabs and the conductive coating on the PVDF film. [0010] The PVDF film with the lead contact tabs affixed to its opposed major surfaces are sandwiched between upper and lower layers of double-sided adhesive tape that adhere to the film layer, to a portion of the leads and to one another. Next, a polyurethane film layer is adhered to the exposed sides of the double-sided tape. The polyurethane layers extend beyond the perimeter edges of the double-sided tape and the edge portions of the polyurethane layers are heat sealed to one another to totally encapsulate the PVDF film, the lead tabs and the layers of double-sided adhesive tape in a moisture-proof manner. DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 is an exploded view of the reusable sensor constructed in accordance with a first embodiment of the invention; [0012] FIG. 2 is an expanded edge view of the embodiment of FIG. 1 ; and [0013] FIG. 3 is an exploded view of an alternative embodiment of a snore sensing element made in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT [0014] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the device and associated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof and words of similar import. [0015] Referring to FIGS. 1 and 2 , there is shown an exploded perspective view and an exploded edge view of a reusable airflow sensor especially designed for use with a polysomnograph in a sleep lab setting. The sensor comprises as its active element a polarized PVDF film layer 10 that, in the embodiment of FIG. 1 , is somewhat Y-shaped having rounded lobes 12 , 14 , diverging from one another at a predetermined angle and a stem portion 16 . The PVDF film layer 10 includes metallization layers on opposed major surfaces thereof represented by the cross-hatching thereon. The metallization layers serve to collect the charge produced by the PVDF film due to respiratory air flow impinging on the transducer or due to temperature change. [0016] Affixed to the opposed major surfaces of the stem portion 16 are conductive electrode tabs 18 and 20 that are crimped and/or soldered to the exposed ends of insulated lead wires 22 and 24 , respectively. To insure intimate contact between the conductive electrodes 18 and 20 and the metalized surfaces of the PVFD film 10 , a conductive adhesive, such as that sold under the trademark ARclad® by Adhesives Research, Inc., is used. This material comprises an adhesive that is laced with conductive carbon particles that serves as a bonding agent between the electrodes 18 and 20 with the metalized layers adhered to the PVDF film. The ARclad® adhesive is represented in FIG. 1 by references numerals 26 and 28 . [0017] Pyro/piezo transducers of the type described can be procured from Measurement Specialties, Inc. of Morristown, Pa., with leads already attached to the metalized PVDF film, but the film shape is of one type—rectangular—and of a standard size. [0018] First and second double-sided adhesive tape layers 30 and 32 cut to conform to the shape of the PVDF layer 10 are adhered to the opposed surfaces of the film layer 10 helping to secure the tab electrodes 18 and 20 and a portion of the wire leads 22 and 24 leading to the conductive tabs in place. Completing the assembly are first and second layers 34 and 36 of polyurethane film that are also cut to be of generally the same shape as the PVDF layer 10 , but larger in size than the adhesive tape layers 30 and 32 . During assembly, the polyurethane plastic layer 34 is adhered to the exposed adhesive surface of the double-sided tape layer 30 . Likewise, the polyurethane plastic layer 36 is bonded to the exposed adhesive on the tape layer 32 . [0019] Because the polyurethane plastic layers 34 and 36 are of a larger area than the tape layers 30 and 32 , a perimeter portion 38 extends beyond the edges of the tape layers 30 and 32 . The perimeter portions of the polyurethane layers 34 and 36 are brought into contact with one another and fused together in a thermal bonding process. As a result, the interior components sandwiched between the outer polyurethane plastic layers 34 and 36 are fully encapsulated and thereby sealed against ingress of moisture even when exposed to cleaning solutions and sterilants. Also, because of the manner in which the electrode tabs 18 and 20 are adhered to the PVDF layer 10 by the ARclad® conductive adhesive and the way in which the portion of the leads leading thereto are adhesively attached to the tape layers 30 and 32 , testing has shown that the wire leads 22 and 24 will break before the electrodes will pull free from the sensor assembly. [0020] While polyurethane film is preferred for the outer layers 34 and 36 , because it is heat-sealable and hydrophobic, other non-porous heat sealable plastic materials may also be used to encapsulate the PVDF and the distal ends of the lead wires. [0021] In use, the sensor of FIG. 1 is placed on the upper lip of a subject such that the lobes 12 and 14 are proximate the nasal openings and the stem portion 16 extends beyond the upper lip. Sensor 10 is held in place on the lip by means of a suitable adhesive or by using a strip of adhesive tape. Changes in temperature due to inspiratory and expiratory airflow that impinges on the sensor produce an output signal component proportional to the temperature swings. Should there be episodes of snoring, the sensor that is in contact with the skin, will sense the snoring vibration and the piezoelectric properties of the PVDF will result in a second signal component that varies with the intensity of the snoring. These signals are fed to a polysomnograph instrument where signal processing circuitry is used to separate the pyro signal from the piezo signal. [0022] Turning next to FIG. 3 , there is shown an alternative embodiment especially designed for attachment to the throat area of a sleeping patient in a sleep lab environment. This sensor is also reusable in that it can be cleaned. It is substantially identical in its construction to the embodiment as illustrated in FIGS. 1 and 2 and corresponding numbers, only primed, are applied to the embodiment of FIG. 3 . The only difference between the embodiments of FIG. 1 and FIG. 3 is the shape of the sensor. In that the constructional details have already been explained in connection with the embodiment of FIGS. 1 and 2 , it is felt unnecessary to repeat it in connection with the embodiment of FIG. 3 . [0023] 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 such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
A sensor for use with a polysomnograph in a sleep lab setting is made reusable by laminating a PVDF film and associated lead contacts within a flexible, moisture-impervious plastic envelope that is hermetically sealed about its periphery. Lead terminals within the envelope are adhered to the metalized surfaces of the PVDP film using a conductive adhesive which inhibits dislodgement of the leads from the sensor even with rough handling and cleaning.
0
This is a division of application Ser. No. 739,081 filed Aug. 1, 1991, U.S. Pat. No. 5,163,416. This invention relates generally to high temperature industrial heat treat furnaces and more specifically to ceramic radiant heat tubes employed in such furnaces. The invention is particularly applicable to and will be described with specific reference to a novel heat treat vacuum furnace employing a specific radiant tube position and a vacuum seal arrangement for the ceramic tubes. However, the invention has broader application and may be used in any high temperature, industrial heat treat furnace application. INCORPORATION BY REFERENCE Gas Research Institute, assignee of this invention and the party who funded the development work which gave rise to this invention, made available to the public in October, 1988 Report No. GRI-88/0159, authored by at least one of the inventors herein, and this report, since it discusses the feasibility of the furnace to which this invention relates, is incorporated herein by reference so that the specification herein need not define in great detail the furnace concepts and principles referred to herein. In addition, U.S. Pat. No. 4,802,844 is incorporated herein by reference so that details of a lift hearth mechanism need not be disclosed nor discussed in detail herein. In addition, U.S. Pat. No. 4,963,091 is incorporated herein by reference so that details of the furnace configuration need not be discussed in detail herein. BACKGROUND Certain heat treat processes and other related industrial heating applications such as brazing and sintering have, at least for certain applications, been traditionally conducted in industrial vacuum furnaces. Standard vacuum furnaces are constructed with a double wall configured in a cylindrical or spherical shape and employ a water jacket between the walls for cooling. This type of furnace is considerably more expensive than the conventional, box type standard atmosphere furnace which operates at atmospheric pressure and which is constructed by fibrous insulation attached to a furnace casing of sheet steel. Because of the water jacket construction in vacuum furnaces, heating is conducted in a vacuum furnace by means of graphite bars or electrodes surrounding the work and connected to a source of electrical power by electrical feedthroughs extending through the casing. In contrast, standard atmosphere furnaces typically use gas fired burners for heating which is a more cost efficient form of energy. Because the atmosphere within a standard atmosphere furnace must be precisely controlled, high temperature, standard atmosphere furnaces indirectly heat the work (i.e. heat by radiation for temperatures in excess of about 1500° F.) by means of burners which fire their products of combustion into radiant tubes which extend into the furnace. The radiant tubes may be either of the single-pass or the single-ended, double-pass type and the prior art is replete with numerous arrangements and configurations of such radiant tubes. Until recently, components within standard atmosphere furnaces constructed of high alloyed steel limited the temperature at which such furnaces operated to a maximum of about 1750°-1850° F. Standard atmosphere furnaces which operate at such temperatures are referred to today as "high temperature" furnaces. Several years ago, Surface Combustion, Inc., under a contract funded by GRI developed an ultra-high temperature, standard atmosphere furnace now marketed by Surface under the brand name or trademark "ULTRACASE". Reference should be had to GRI U.S. Pat. No. 4,802,844 for a discussion of the deleterious effects temperature has on the life of steel alloys when the temperature begins to exceed 1850° F. In the '844 patent, a retractable hearth lift mechanism is employed to permit the furnace to operate at temperatures of about 2000° F. The limiting factor preventing furnace temperature in excess of about 2050° F., except for short durations, is the life of the high alloy steel radiant tube, i.e. thermal fatigue. That is, standard atmosphere furnace construction techniques using various ceramic types of insulation applied to a standard furnace casing sufficiently insulates the furnace to permit it be operated at temperatures in excess of 2000° F., i.e. at temperatures in the ranges approaching or equal to that utilized in vacuum furnace treatments. The limiting factor preventing higher furnace temperatures in gas fired, standard atmosphere furnaces is the radiant tube. GRI Report 88/0159 discusses in depth the feasibility of using a "soft" vacuum defined as 10-250 torr coupled with furnace purging in a conventional atmosphere type furnace to perform those types of heat treat and heat treat type processes heretofore accomplished in vacuum furnaces where the work is heated in a "hard" vacuum below 10 -1 torr. The report concludes that at "soft" vacuum levels of about 100 torr and at elevated temperatures of between about 1950°-2350° F. it is possible to metallurgically perform a number of such processes, which are detailed in the report. Thus, the report maintains that it is feasible to use a cost effective, modified atmosphere type furnace construction at high temperature under soft vacuum levels to perform certain types of industrial heat processes heretofore not thought possible in standard atmosphere furnaces. Standard atmosphere furnaces can be heated electrically. However, because of exposure to various furnace atmospheres (not present in "hard vacuum" furnaces), electrical heating elements have to be shielded, i.e. placed within radiant heat tubes. More importantly, operating cost efficiencies dictate that gas burners be used. Again, this means, because of furnace atmosphere composition requirements, radiant tubes. Recently, ceramic radiant tubes constructed of silicon carbide have been introduced into the furnace art as replacements for steel alloy radiant tubes. While their commercial acceptance is not widespread, ceramic radiant tubes have much higher tensile strength at elevated temperatures (i.e. the temperature ranges under consideration) when compared to steel alloy radiant tubes. While investigation of the suitability of ceramic radiant tubes to the "soft" vacuum furnace application under discussion is still continuing, it is known that ceramic radiant tubes are extremely brittle. Special arrangements have to be undertaken when ceramic tubes are used in a horizontal placement position to minimize stress placed on the tubes. Furthermore, because of the elevated temperatures at which the furnace is operated, special consideration has to be given to the heat flux imparted by the tubes to the work so as to uniformly heat the work. In this regard, it is known by Surface Combustion, Inc. to position radiant tubes uniformly about work centered on the centerline of a cylindrical furnace similar to that used herein and operated under vacuum conditions. With respect to conventional vacuum furnaces, electric heating elements have been positioned to circumscribe the work and temperature uniformity is not as critical a problem as it is when point or line sources of radiant heat are used to heat the work by radiation. Finally, the ceramic radiant tube must be secured to the steel furnace casing in such a way which permits the tube to expand without incurring undue stress and at the same time, seal the tube so that leakage of deleterious oxygen into the furnace chamber which is under a vacuum does not occur. With respect to vacuum sealing, it is well known in the vacuum furnace art to seal the furnace door by means of elastomer seals which are kept cool by a water jacket. It is also known, for example, by Surface Combustion's internal heat exchanger tubes marketed under the brand name or trademark INTRA-KOOL, to seal the tube at the casing by means of an elastomer seal adjacent a water jacket. SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to provide a preferred ceramic tube placement for an industrial heat treat furnace which employs a sealable arrangement for ceramic radiant heat tubes. This object along with other features of the invention is achieved in an industrial, heat treat vacuum furnace which includes a steel casing to which fibrous insulation is attached and which defines a furnace chamber contained therein. A plurality of ceramic, radiant heat tubes extend into the chamber through the casing. Each radiant heat tube has a tube flange at one axial end positioned externally of the casing and the flange has an underside surface facing the casing and an outside face surface at the axial end thereof. A sealing mechanism capable of vacuum sealing the ceramic tube flange to the casing includes a support flange member engaging the tube flange's underside surface at its axial end face and the support flange member is secured to the casing at its opposite axial end. A burner flange member has an axial end face which sealingly engages the tube flange's outside face surface. The support flange member has a water jacket formed therein for flowing a coolant therethrough. At least one of the support flange's end face and the radiant tube's underside surface has a radially outward circumscribing groove formed therein and an elastomer seal is placed in the groove. A clamp mechanism is then provided for joining the support flange member and the burner flange member to compress the elastomer seal. Importantly, the clamp mechanism pulls the radially inwards surface of the support flange's end face and tube underside surface into ceramic-to-metal contact which prevents movement between radiant tube and support flange so that the elastomer seal will not be exposed to sliding surface contact which can adversely wear and affect the seal's ability to vacuum seal the connection. The ceramic-to-metal contact provides adequate thermal coupling thereby lowering the temperature of the radially outward portion of the ceramic flange which contacts the elastomer seal. This cooling is necessary to maintain the elastomer seal below the maximum normal operating temperature of the elastomer seal. Vacuum grease between the support flange end face and the radiant tube's underside surface is used to "fill in" any surface imperfections to assure solid area contact between ceramic tube and steel support flange. Alternatively, a non-ferrous metallic washer can be placed in the recess formed in the support flange. In accordance with another aspect of the invention, the support flange member includes an expansion joint positioned between axial ends of the support flange member so that the support flange can move as the radiant tube thermally expands and contracts to thus relieve bending stress otherwise placed on the ceramic tube. Preferably, the burner flange member employs the same seal arrangement as the support flange member to seal the outside face surface of the radiant tube. The burner flange and support flange members are engaged by the clamp mechanism which is positioned radially outwardly from the elastomer seals for drawing the burner flange and support flange together under a spring tension bending movement to secure the desired radially inwardly positioned ceramic to metal contact while accomplishing compression of the elastomer seals to effect vacuum sealing. In accordance with another feature of the invention, the burner flange has a support plate at its opposite axial end and an expansion joint is in between the support plate and the burner flange's axial end face which is in contact with the outside face surface of the radiant tube. Mounted to the support plate is a conventional burner. Significantly, at least two support legs extend between and are attached to the support plate and the furnace casing for fixing the longitudinal distance that the support and burner flanges with the radiant tube flange clamped therebetween extends from the casing. The clamp mechanism has first and second generally diametrically opposed recesses formed therein and first and second pivot pins fixed to the support legs are positioned within the first and second recesses. This pivoting pin connecting provides an articulated connection which supports the radiant tube at its flange in one direction or on one axis while permitting the radiant tube be unconstrained in movement in an orthogonal direction of motion or on another axis. In this manner, ceramic radiant tubes can be horizontally positioned and supported at the flange to relieve tube stress, while still being free to move in another direction to permit thermal expansion and alleviate thermal stress. In accordance with still another aspect of the invention, a gas type flexible diaphragm may be optionally provided. The diaphragm circumscribes and encases the support flange and the burner flange over a portion thereof to define a sealed, annular space adjacent the radiant tube's flanged end. A purge gas inlet in fluid communication with the annular space provides a purge gas to the space at a slight pressure and a vent means for venting the purged gas from the annular space is also provided whereby, should some leakage occur during operation of the vacuum furnace, the leakage will not be detrimental to the furnace operation nor to the external environment surrounding the furnace. In accordance with another feature of the invention, the sealing arrangement described can be readily applied whether the radiant tube be the single-ended, double-pass type or the single-pass type. In accordance with still another feature of the invention, the steel casing is formed as a horizontally extending cylinder having a door at one end and a closed end wall at its opposite end. A ceramic, fibrous insulation attached to the casing provides insulation for the furnace chamber with the furnace chamber being cylindrical and having a longitudinally extending centerline about which the chamber is symmetrical. A hearth for supporting the work is secured to the casing and extends radially inwardly into the chamber a fixed distance such that the longitudinally extending centerline of the work is vertically offset from the longitudinally extending centerline of the furnace chamber. A plurality of radiant tubes are spaced in equal circumferential increments about the work's centerline so that the radiant tube adjacent the top portion of the work is closer to the work than the radiant tube adjacent the bottom portion of the work which is positioned between the hearth posts. This position, despite the offset arrangement, radiantly heats the work at substantially equal rates about all of its exposed surfaces. Specifically, only four (4) radiant tubes need be applied to achieve the high heat input at the desired uniform heating rate. In accordance with a more specific feature of the invention, the work is vertically movable to desired positions within the furnace chamber. A fan for providing convection heating is utilized to effect uniform heating of the work at low temperatures thus reducing the overall heating time. A microprocessor controls the hearth position, the fan speed and the pressure within the furnace chamber to provide a fast, uniform heat cycle utilizing both convection and radiant heat transfer. Accordingly, it is an object of the subject invention to provide a furnace seal arrangement for a ceramic radiant heat tube. It is another object of the invention to provide a seal arrangement for a ceramic radiant tube which allows free floating of the outside flanged end of the tube while providing a support for the tube's flanged end to relieve stress on the tube and avoid fracture. Still another object of the invention is to provide in combination with a seal for a ceramic radiant tube, an articulated joint arrangement which allows the radiant tube to be mounted horizontally to the furnace. Still yet another object of the invention is to provide a seal arrangement for a ceramic radiant heat tube which is effective to provide a seal against a vacuum drawn within the furnace to which the tube is mounted. Still yet another object of the invention is to provide a seal and gas purge arrangement for a ceramic radiant tube which permits the tube to be used in a vacuum environment. Still yet another object of the invention is to provide a fuel fired standard atmosphere furnace capable of operating at a soft vacuum because of the sealing arrangement employed for the ceramic radiant heat tubes used therein. Still yet another object of the invention is to provide a preferred placement of radiant heat tubes in a cylindrical furnace to uniformly heat the work at high temperatures. A still further object of the invention is to provide a fast heat cycle which is able to uniformly heat the work. Still yet another object of the invention is to provide a ceramic radiant tube arrangement capable of operating at high temperatures in excess of 2050° F. in a standard atmosphere type construction furnace employing blanket, fibrous insulation. These and other objects will become apparent from a reading of the Detailed Description section taken together with the drawings which will be described in the next section. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which form a part hereof and wherein: FIG. 1 is a partial schematic, longitudinally-sectioned view of a prior art sealing arrangement for a ceramic radiant tube; FIG. 2 is a partial schematic, longitudinally-sectioned view of a radiant tube similar to FIG. 1 showing the sealing arrangement of the present invention; FIG. 3 is a schematic, longitudinally-sectioned side view of the sealing arrangement of the present invention; FIG. 4 is a partial schematic, longitudinally-sectioned top view of the sealing arrangement of the present invention similar to that shown in FIG. 3; FIG. 4A is a schematic partially sectioned view of an alternative embodiment of the mounting arrangement shown in FIG. 4; FIG. 5 is an end view of the burner flange employed in the present invention; FIG. 6 is a longitudinally sectioned view of the burner flange taken along line 6--6 of FIG. 5; FIG. 7 is a detail of the burner flange taken along line 7--7 of FIG. 5; FIG. 8 is a schematic view of both a single-ended double-pass radiant tube and a single-pass radiant tube using the present invention; FIG. 9 is a partial, longitudinally-sectioned view similar to FIGS. 1 and 2 showing an alternative embodiment of the present invention; FIG. 10 is a detail of the flange shown in FIG. 9 similar to that illustrated in FIG. 7; FIG. 11 is a schematic, cross-sectioned end view of a furnace showing the position of the radiant tubes relative to the work and to the furnace; and FIG. 12 is a schematic view similar to FIG. 3A of U.S. Pat. No. 4,802,844 showing a seal for the hearth post shown in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and are not for the purpose of limiting the same, there is shown in FIG. 1 a partially sectioned, schematic representation of a prior art sealing arrangement employed for sealing a single-ended, double-pass ceramic radiant tube 10. As used herein, ceramic tube means a silicon carbide, SiC, tube. Testing done to date indicates that reaction bonded SiC tubes have permeability characteristics adequate for the use disclosed herein. Specifically, Coors SCRB 210 tubes were tested in the development program. Advancements in SiC tubes are continuing to occur and alpha sintered SiC tubes may be particularly applicable to the installation discussed herein. Accordingly, the term "ceramic" as used in referring to the radiant tubes used herein and as used in the claims means any and all silicon carbide tube compositions. Referring still to FIG. 1, the partial sectioned view discloses a single-ended, double-pass radiant tube. Those skilled in the art will understand that this arrangement includes a ceramic outer tube 12 which is closed at its end 14 which extends into the furnace and which receives a ceramic, open ended, inner tube 13. Inner tube 13 extends longitudinally a greater distance outside of the furnace than outer tube 12 where it is clamped to a burner (not shown--see FIG. 3). Conventionally, the burner includes a gas supply tube 15 which extends longitudinally and concentrically within inner tube 13. In operation, combustion air is injected into the annulus 16 in between inner tube 13 and gas supply tube 15 and mixes with the gas supplied to gas supply tube 15 when the gas exits the tube. The hot products of combustion thereafter travel down inner tube 13 until they are dead-ended at the closed end of outer tube 12. The gases then pass through the annular exhaust space 18 between inner and outer tubes 12, 13 where they are subsequently exhausted to the stack. The length of gas tube 15 is controlled to produce a heat release point within the furnace and various mixing schemes are employed so that the heat is uniformly released along the length of inner tube 13 within the furnace enclosure. This is a preferred form of radiant heat since the products of combustion initially heat inner tube 13 which in turn radiates the heat to outer tube 12 and to the work while the exhaust gas likewise heats outer tube 12. Further, in a single-ended, double-pass radiant tube 10, only one opening is required in the furnace. The sealing arrangement for inner tube 13 is not critical and can be effected by any conventional, fibrous seal firmly compressed against the flange end of inner tube 13 because inner tube 13 being open ended and disposed within outer tube 12 is free to thermally expand and distort in exhaust space 18. More importantly, because inner tube 13 is sealed within outer tube 12 should inner tube 13 crack, i.e. fail, there is no adverse effect on the operation of the radiant tube. Accordingly, the concern is to seal outer tube 12 in a manner which prevents the outside ambient atmosphere from entering the furnace and vice versa and to effect such seal without outer tube 12 cracking or failing when it is heated. To avoid any confusion, a space must exist between outer tube 12 and the furnace where outer tube 12 passes through the furnace and this space, indicated by reference numeral 19, must be sealed. Outer tube 12 has, at its open axial end, an annular flange 20 which in turn has an annular underside surface 21 and an annular, axial end face or outside surface 22. In the prior art sealing arrangement shown in FIG. 1, an tubular support flange member 25 extends externally of furnace casing 26. Secured to the interior of furnace casing 26 by any conventional means is insulation 27, preferably ceramic fibrous insulation. Annular support flange member 25 is secured to furnace casing 26 by any conventional means, i.e. welding, at one axial end thereof and at its opposite axial end has an annular, radially outwardly extending flange end 29 which in turn has an annular, axial end face surface 30 facing or adjacent annular underside surface 21 of outer tube 12. An annular tubular burner support member 32 has at one of its axial ends a radially outwardly extending burner flanged end 33 which in turn has an annular, axial end face surface 34 adjacent or facing outside surface 22 of outer tube 12. An annular, conventional fibrous seal 35 is disposed between underside surface 21 of outer tube 12 and axial end face surface 30 of tubular support flange member 25. Similarly, a fibrous seal 35 is disposed between outside surface 22 of outer tube 12 and axial end face surface 34 of tubular burner support member 32. A spring tension clamp mechanism pulls burner flange end 33 and support flange end 29 together to supposedly clamp and seal shoulder flange 20 of outer tube 12. The clamp mechanism shown includes a plurality of bolts 37 extending through aligned openings in burner flange end 33 and shoulder flange end 29 with each bolt 37 carrying a spring 38 compressed between fastener end and flange to exert a precompressed spring force to fiber seal 35. The prior art sealing arrangement of FIG. 1 employing fiber seals 35 cannot vacuum seal outer tube 12. Leakage past fiber seals 35 will always occur irrespective of the tensioning force placed on springs 38 unless springs 38 are compressed solid but when this occurs, outer tube flange 20 will crack. Because of the inability of the prior art mechanism to non-destructively seal outer tube 12, the present invention was developed. Inherently, there are similarities between any sealing mechanism and, for this reason, the prior art was described in detail and reference numerals used in FIG. 1 will describe like parts and components of the present invention so that the different inventive aspects of the invention can be more readily ascertained. Referring now to FIG. 2, there is shown a sealing arrangement for inner ceramic tube 12 disposed within outer ceramic tube 13 having a radially outwardly extending shoulder or flange 20 which in turn has an annular underside surface 21 and an outwardly facing annular outside surface 22. A tubular support member 25 has a radially extending flange end 29 with an especially configured annular axial end face surface 30 facing tube underside surface 21. A tubular burner support member 32 has a burner support flange end 33 which in turn has an especially configured axial end face surface 34 facing tube outside surface 22. A clamp mechanism similar to that employed in prior art FIG. 1 is utilized but produces different results as explained hereafter. More specifically, in the fabrication shown in FIG. 2, a radially outwardly extending annular shoulder 40 extends from burner flange end 33 and a similar radially outwardly extending shoulder 41 extends from support flange end 29. A plurality of circumferentially spaced longitudinally extending openings 42 are drilled in burner flange annular shoulder 40. Similarly, a like plurality of identically circumferentially spaced longitudinally extending openings 43 are drilled in support flange annular shoulder 41. Openings 42, 43 are aligned with one another and a plurality of threaded studs 37 or bolts extend through openings 42, 43. Compression spring 38 fits over one of the ends of stud 37 and fasteners 46 applied to the axial ends of each threaded stud 37 compresses spring 38 against one of the fasteners 46 and an associated flange shoulder 40 or 41 to clamp support flange end 29 against burner flange end 33 compressing or sandwiching radiant tube flange 20 therebetween. It is to be noted that the clamp arrangement is radially outward or outboard of radiant tube's flange 20 and exerts a bearing pressure on flange 20. As described thus far, the invention is similar to the prior art. An optional diaphragm feature is shown in FIG. 2. This optional feature includes a furnace side annular housing 50 secured to support flange member 25 beneath support flange end 29 and a burner side annular housing 51 is similarly applied to annular burner flange end 32 which longitudinally extends away from burner flange end face 33. A diaphragm 52 is clamped between furnace side housing 50 and burner burner sill housing 51 with strap clamps 57 to define a sealed, purged gas space 54 which annularly extends about support flange member 25 and tubular burner support member 32. A purge gas inlet 55 is provided in one of the annular housings 50, 51 and similarly, a purge vent is also provided in one of the annular housings 50, 51. It is contemplated that a purge gas, i.e. an inert gas such as nitrogen, at a slight pressure of say 2-3 inches water column would fill purge gas space 54 and should leakage, (i.e. a vacuum leakage past the seal) through furnace space 19 occur, the purge gas would be drawn into the furnace chamber where it would do no harm to the heat treat process. This again is an optional feature and is not necessary for the sealing arrangement of the present invention. It can, however, be used in conjunction with the prior art seal disclosed in FIG. 1 for vacuum application. If used in the prior art seal shown in FIG. 1, appropriate valving would have to be applied to purge gas inlet 55 since there would be a constant draw of the purge gas into the furnace chamber resulting from leakage from fiber seals 35. If use with the present invention, diaphragm 52 would be a fail-safe feature. Referring now to FIGS. 2, 5, 6 and 7, the construction of burner flange end 33 and annular, axial end face surface 34 of tubular burner support member 32 is identical to the construction of annular support flange end 29 and annular axial end face surface 30 of tubular support member 25. Thus, it will be sufficient to describe burner flange end 33 as shown in FIGS. 5, 6 and 7 with the understanding that the same construction applies to support flange end 29. More specifically, burner flange end 33 has a water jacket 60 in the form of a large recess which almost totally circumscribes burner flange end 33. As best shown in FIG. 5, a land 61 extending across water jacket 60 makes the water jacket discontinuous. On each side of land 61 is a tapped water port, one port 63 being an inlet and the opposite port 64, being an outlet or vice versa. Again, as noted in the background, water jackets are conventional. It should also be noted that water jacket 60 is positioned close to burner axial end face surface 34. Axial end face surface 34 includes a radially inward position annular contact surface 65 which extends to the inside diameter of tubular burner support member 32. Adjacent annular contact surface 65 and extending radially outward therefrom is a longitudinally recessed sealing groove 67 and spaced radially outwardly from sealing groove 67 is a longitudinally protruding shoulder 68. Extending radially between annular shoulder 68 and annular sealing groove 67 is an annular recess surface 69. Significantly, recessed surface 69 is longitudinally recessed relative to contact surface 65 as best shown by dimension X in FIG. 7. Positioned within sealing groove 67 is an elastomer seal 70 (shown in FIG. 2) which can be a conventional O-ring made of silicon rubber. With the design illustrated in FIGS. 5, 6 and 7 and the temperature of the furnace chambers at about 2000° F., water jacket 60 reduced the temperature of elastomer seal 70 to about 300+° F. and at this temperature, the seal will not thermally degrade. In order for elastomer seal 70 to effectively seal radiant tube flange 20, seal 70 must be positioned radially outward from annular contact surface 65. As noted above, the clamp mechanism positioned outboard of seal 70 exerts what could be viewed as a bending moment on burner and support flange ends 29, 33. By providing recess surface 69, the moment is resisted by contact surface 65 bearing against tube outside surface 22 (and for support flange member 25, tube underside surface 21). Contact surface 65 must be milled smooth and the finish of annular underside surface 21 and annular axial end face surface 22 of outer tube 12 must also be smooth. Further, a vacuum sealing grease such as Dow Corning Vacuum Sealing Grease, is used to fill in any surface imperfections between flange and radiant tube, not for the purpose of establishing a vacuum seal between tube and flange, but to establish a smooth continuous contact area between the surfaces which are tightly engaged by the radially outboard compression mechanism discussed above. What the contact area does then is to permit the elastomer seal 70 to be compressed in groove 67 with material flow of the seal extending into the space between tube flange and recess surface 69 so that seal 70 need only function to seal the radiant tube. Stated another way, the metal-to-ceramic tube-flange contact over its entire area prevents any movement between tube and flange which would otherwise upset the sealing capabilities of elastomer seal 70. Tube-flange movement will not only wear seal 70 to produce vacuum leakage, but could also upset seal 70 to produce leakage. It is important then that contact surface area 65 be made as large as possible and it is preferred for the furnace application under discussion that the radiant tube diameter be 6". The invention has worked with radiant tubes of 35/8" diameter but larger tube sizes, preferably in tube diameters of about 6", enhances the sealing characteristics of elastomer seal 70. As best shown in FIG. 6, tubular burner support member 32 has an annular support plate 74 or other means of gas tight attachment formed at its axial end opposite burner flange end 33. A cylindrical body section 75 extends between support plate 74 and burner flange end 33. Within body section 75 is a conventional expansion joint 76 or bellows. Similarly, as best shown in FIGS. 3 and 4, tubular support member 25 likewise has a cylindrical body section 78 extending between its axial ends and body section 78 in turn has an expansion joint 79 as part thereof. Expansion joints 76, 79 permit an articulated joint connection to be applied to the tube mounting arrangement to reduce tube stress when the radiant tube is mounted in a horizontal direction. The articulated joint connection can also be applied if the radiant tube is mounted in a vertical direction to likewise reduce tube stress due to unplanned externally applied forces. It is possible because of the rigidity of expansion joint 79, 76 to support outer tube 12 solely on these expansion joints by the arrangement illustrated assuming some support for exhaust/burner housing 80. However, such an arrangement will exert a bending stress on outer tube 12 and at the temperature ranges at which the furnace is to be operated, i.e. furnace temperatures approaching 2350° F. require flame temperatures within the radiant tube as high as 2700°-2800° F. resulting cumulative thermal-support-bending stress which could result in premature failure of outer tube 12. The radiant tube horizontal mounting position is shown in FIGS. 3 and 4. In FIG. 3, which is a side view of the arrangement, the articulated joint connection is not shown for drawing clarity purposes. The articulated joint connection is shown in the top view illustrated in FIG. 4. Support plate 74 is conventionally mounted to an exhaust/burner housing 80 which includes an exhaust section 81 having an outlet 83 connected to the stack for exhausting products of combustion in a known manner. Exhaust/burner housing 80 also has a burner section 84 sealingly fastened to exhaust section 81. Plumbed into burner section 84 is a gas line 85 for a gaseous fuel and an air line 86 for combustion air. The axial end of inner tube 13 is sealed by a conventional, fibrous ceramic seal when exhaust section 81 and burner section 84 are bolted together. This is a conventional seal arrangement for inner tube 13. In the schematic illustration shown in FIG. 3, it is to be understood that the furnace casing portion 26 illustrated is the end wall of a cylindrically shaped furnace which end wall is spherical in configuration. Interiorly of furnace casing 26 and furnace insulation 27 is a cylindrical furnace chamber indicated schematically by reference numeral 28 and within furnace chamber 28 is a radiant tube support indicated schematically by reference numeral 88. To minimize tube stress, an articulated joint connection is provided to support outer tube 12 in a horizontal direction while permitting outer tube 12 to move freely in a lateral or orthogonal direction. As best shown in FIGS. 5 and 6, two diametrically opposed pivot pin holes 90 are drilled into annular shoulder 40 of burner flange 33. Alternatively, pivot pinholes 90 could be drilled into support flange end 29 of support flange member 25 and, in fact, in the view shown in FIG. 4 pivot pinholes 90 are placed in support flange 29 and not in burner flange 33. Referring to FIG. 4, two diametrically opposed support bars 92 extend from support plate 74 and are fixed such as by welding to furnace casing 26. This fixes the distance that tubular support member 25 and tubular support burner member 32 with outer ceramic tube 12 clamped therebetween extends from furnace casing 26. Each support bar 92 has a pivot support plate 93 mounted thereto by means of fasteners 94 and spacers 95. Slotted holes in support plate 93 and/or support bars 92 (not shown) are provided for adjustment. Extending from each pivot support plate 93 is a pivot pin 96 which fits within pivot pinhole 90. Thus, in the top view shown in FIG. 4, pivot pins 96 provide a support for the outer tube's flange 20 while permitting the support flange 29 of support flange member 25 to pivot in the direction shown by reference numeral arrows 93 in FIG. 3. This direction, as noted above, is orthogonal to the axis or more precisely the to axes at which pivot pins 96 support outer tube 12. The support can be totally rigidized by providing two additional, diametrically opposed support bars offset 90° from support bar 92 shown and corresponding pivot pin and pin recesses provided in a flange end. However, this defeats the joint connection desired. Alternately, as shown in FIG. 4A, pivot support plates 93 may be replaced by singularly bolted support posts 99. The cylindrical contour of these posts may be better suited for sealing to a diaphragm 52 described earlier with reference to FIG. 2. An elastomer boot 98 vulcanized or glued to diaphragm 52 and clamped around post 99 would accommodate a small pivoting motion of radiant tube flange 20 while maintaining the slight positive gas pressure within diaphragm 52. The sealing arrangement for the radiant tube of the present invention has been discussed with reference to a radiant tube of the single-ended, double-pass type. This is again illustrated schematically in the top portion of FIG. 8. The invention is also applicable to a radiant tube of the single-pass type 100 also illustrated schematically in FIG. 8. In the single-pass application, one ceramic radiant tube 100 has a flanged axial inlet end 101 which is the same as that described for outer tube 12 in the single-ended, double-pass type and also, an identical axial outlet flanged end 102 is provided at the opposite of tube 100. In the preferred mounting arrangement for ceramic tube's inlet flanged end 101, there is provided a support flange member expansion joint 79 and a burner flange member expansion joint 76 which in turn has a support plate to which burner section 84 is provided. Support bars 92 can be provided to the burner flange support plate as described with reference to FIGS. 3 and 4 and an articulated joint connection provided. With respect to sealing outlet flanged end 102, it is sufficient to provide on one side of outlet flanged end 102, support flange member 25 with expansion joint 79 and on the opposite side of axial outlet flanged end 102 to provide exhaust section 81 which can be sealed by a conventional fibrous gasket. In fact, it is not necessary to have expansion joint 79 for tube outlet end 102 and an alternative arrangement is shown in FIGS. 9 and 10. Referring now to FIGS. 9 and 10, reference numerals previously used to describe parts and components of the sealing arrangement will be used again to describe the same parts and components where possible. In the single-pass ceramic radiant tube mount arrangement illustrated, tubular support flange member 25 is a composite sold block arrangement clamped by fasteners 104 to furnace casing 26 and sealed thereto by means of conventional fibrous ceramic gasket 105. Formed in support flange member 25 is water jacket 60 and water inlet 63 to water jacket 60 is illustrated. Rigidly clamped by means of threaded fasteners 107 threadedly received in tapped holes (fastener nuts not being shown) is exhaust section 81. A conventional annular ceramic fibrous washer 108 seals outside surface 22 of outlet flange 102 with exhaust section 81. Elastomer seal 70 is used to seal tube's underside surface 21 with axial end face surface 30 of support flange member 25 as discussed in the preferred embodiment. A slightly different arrangement is used to effect the seal in this alternative embodiment and is best shown in FIG. 10. In FIG. 10, the groove recess 67 illustrated in FIG. 7 extends from shoulder 68 to the inside diameter of support flange member 25. A non-ferrous metallic washer 110 such as brass or copper rests on groove surface 67 and extends from the inside diameter of tubular support flange member 25 radially outwardly to a position similar to that where groove 67 would begin in FIG. 7. The face surfaces of washer 110 are softer than the steel of support flange member 25 and assures the desired surface contact area between tube and flange member and this occurs whether or not vacuum grease is applied to washer 110. The arrangement however, without the application of vacuum grease is not as good, from a sealing consideration, as the arrangement with the application of vacuum grease. Elastomer seal 70 is compressed in the space between the outer circumferential edge of washer 110 and shoulder 68 and because movement does not occur between radiant tube and washer 110, seal 70 is effective to prevent vacuum leakage. It is noted that the clamp pressure is again exerted radially outward of seal 70 to produce pressure on washer 110. Referring now to FIG. 11, there is shown in schematic representation a cross-sectional slice of the furnace employing the radiant tubes looking endwise into the furnace. As noted in the discussion above, the sealing arrangement for the radiant tube becomes critical because a slight vacuum (10-250 torr) is pulled in the furnace. While the invention could be applicable as a sealing arrangement for a standard atmosphere, box type furnace, its specific application is for use in a vacuum furnace constructed in accordance with conventional type, fibrous ceramic insulation applied to a relatively thin walled furnace casing 26 (approximately 1/4-1/2" plate). This construction can withstand high temperatures under consideration while generating temperatures of about 400° F. at the furnace casing 26. Because a vacuum is pulled, the furnace preferably has a spherical or cylindrical shape and because capacity requirements dictate loading the workpieces into rectangular work trays or baskets 120, the furnace is preferably cylindrical. (In "hard vacuum" applications, the furnace or vessel configuration is usually spherical or cylindrical because such shapes are best able to resist vacuum deformation. In the "soft vacuum" application under discussion, a rectangular or box furnace configuration could have sufficient structural integrity to withstand vacuum levels under discussion. However, heat transfer considerations as well as aesthetics dictate a cylindrical or spherical configuration.) The end wall of the furnace (FIGS. 3, 4) is preferably spherical and the door (not shown) can be either flat or spherical. For process requirements discussed more fully in the GRI report incorporated herein by reference, the temperature of the furnace must be significantly higher than the temperature at which standard atmosphere furnaces operated and considerably higher than even the super high temperature furnaces recently marketed such as Surface's Ultracase furnace (2350° F. versus 2050° F.). Now in order to achieve the heat cycle for heating, both for process and commercial considerations, a tremendous amount of heat must be ramped or input into the radiant tubes to achieve the desired heat rate. This translates into a temperature within the tube as high as 2750° F. At the same time, there is a strict temperature uniformity requirement placed on the process which basically states that the temperature spread between hottest point and coldest point on any surface of the rectangular block, i.e. work basket 120, cannot deviate more than 10° F. In a hard vacuum furnace where the work is heated in vacuum without introduction of atmosphere, graphite electrodes can be placed in various configurations, several of which are patented, to circumscribe basket 120 and uniformly heat the work at the 2350° F. temperatures under discussion. When this is done, the furnace is lined with heat shields to minimize the cold spot resulting from the water cooled walls and to provide some means for re-radiating the heat from the graphite heating elements. As indicated above, in the "soft" vacuum application under discussion, the atmosphere must be constantly purged. That is, heating has to occur in the presence of a furnace atmosphere and that furnace atmosphere can eventually have a deleterious effect on the graphite heating elements. Thus, if heating elements were used in a "soft" vacuum application, they would have to be shielded and encapsulated within the bayonet type radiant tubes. They could not surround the work. In standard atmosphere furnaces of box type configurations, the radiant tubes are placed adjacent the box side walls but the temperatures at which the furnaces operate are considerably less and convection arrangements can be used to distribute the heat to achieve uniformity. At the super high temperature ranges under discussion, heating by convection is insignificant. Thus, the heat input by conduction of the temperature ranges under discussion is unique to the application under discussion. However, it is known from work by Surface Combustion on a cylindrical furnace with fibrous insulation of the type under discussion herein, that radiant tubes centered about the axis of the work and also centered about the axis of the cylindrical furnace will achieve temperature uniformity at least at the temperature ranges of the prior art. That is, the concept of the cylindrical, continuously insulated furnace for re-radiating heat, with or without heat reflecting shields, by a load furnace centered tube arrangement has been recognized. However, at the elevated temperature ranges under consideration in a soft vacuum application, the heat sink characteristics of hearth 121 become significant at the upper temperature ranges. To compensate for the heat sink effect of hearth 121 and the constrictions placed on radiating heat to the work because of hearth posts 140, a radiant tube position has been developed which position is contrary to that one would expect to occur based on existing, computer simulated heat models and the like. In the tube position disclosed in FIG. 11, the number of tubes is minimized in number to four so as to correspond to the four faces of the rectangular work 120. This means that for the heat input required, the diameter of radiant tubes are sized to about 6" in diameter. This, incidentally, has the additional benefit of increasing the contact area of the sealing mechanism described above which then enhances the vacuum sealing characteristics of the seal arrangement. Hearth 121 is then raised relative to the longitudinal centerline of the furnace and the tubes are positioned on the centerlines of the work. This means that the radiant tubes are spaced at unequal circumferential increments about the furnace. More specifically, the center of work 120 is offset vertically upward from the center of furnace insulation 27 by a distance indicated by reference letter Y in FIG. 11. Top most radiant tube 125 and bottom most radiant tube 126 are centered on vertical axis 127 of load 120 which coincides with the vertical axis of furnace casing 26. Importantly, bottom radiant tube 126 is centered between the posts 140 of hearth 121, and spaced a distance "y" further away from work 120. This provides additional heat at the bottom of work 120 where radiation is somewhat constricted by hearth posts 140. However, side radiant tubes 128, 129 are centered relative to the horizontal axis of work 120 which is offset from the horizontal centered axis 130 of the furnace a distance Y". Stated another way, side radiant tubes 128, 129 are shifted an angle designated as "A" in FIG. 11 towards top most radiant tube 125. Thus, relative to furnace casing 26, the circumferential angle between top most radiant tube 125 and side radiant tubes 128, 129 is equal to 90°-A° while the arcuate spacing between side radiant tubes 128, 129 and bottom most radiant tube 126 is equal to 90°+A°. Radiant tubes 125, 126, 128 and 129 are centered on an imaginary arc 130 which is struck from the longitudinal center of the furnace so that each radiant tube is positioned an equal distance from the inside of furnace insulation 27 with the result that furnace insulation 27, to the extent heated by the four radiant tubes in turn radiates heats uniformly to work 120 which is not positioned at the center of the furnace. Longitudinally, single-ended, double-pass radiant tubes extend slightly past the lengthwise edges of the work (not shown) to assure uniform heating of the work edge. The arrangement provides uniform heat within tolerances at the desired rates because the hearth radiation view has been compensated and the cylindrical configuration of continuous insulation 27 provides effective re-radiation of the heat to the work without the necessity of radiation shields and the like. A specific example is as follows: for a load or work basket 120 having 36"×36" dimension with the furnace having an inside diameter of 72" and the tubes placed on arc radius 130 of 30", vertical offset dimension Y would be 51/2" resulting in an angle A of 10 1/2°. Because the work generally comprises loose pieces placed in a basket 120 which may or may not be filled, hearth 121 is contemplated to be movable, for example by a scissors type lift mechanism indicated schematically by reference numbers 145. Lift mechanism 145 permits adjustments to be made to vertical dimension "y" depending on the work load and during the heat cycle the distance y" can be adjusted to achieve the desired uniformity by correcting for the radiation arising from lowermost hearth tube 126. Reference should be had to Surface Combustion U.S. Pat. No. 4,802,844, assigned to GRI, for an example of the scissors lift mechanism 145 used in FIG. 10. Post 140 would extend outside of furnace chamber 28 thus making the hearth function as a heat sink requiring the compensation set forth above. The rope seal mechanism shown in FIG. 3A of the '844 patent which is reproduced and modified as FIG. 12 would be replaced by an elastomer seal 150 (or a plurality of such seals because of wear) coupled with a water jacket 151 to maintain the vacuum in furnace chamber 28. In a normal heating cycle the work of course should be heated to process temperature in the quickest time. It is known that heat transfer can be best effected by convection at low temperatures and by radiation at high temperatures. Convection can be accomplished in the cylindrical furnace configuration by mounting a fan in the furnace end wall. Such an arrangement is disclosed in Surface Combustion U.S. Pat. No. 4,963,091 dated Oct. 16, 1990 and reference should be had to FIGS. 2 and 3 of the Surface patent, incorporated by reference herein, for a cylindrical furnace construction of the type utilized in the furnace under discussion herein. In the '091 patent, a fan in the end wall of the furnace is used to convectively heat the work with the work vertically centered within the cylindrical furnace. This arrangement gives the best uniformity of heat transfer at the low temperature end in the fastest time possible. Importantly, using convection during the initial heating of the work reduces, or eliminates, temperature gradients within the work and this helps during radiation heating of the work at the high temperature end of the cycle in the sense that the radiation heating maintains rather than establishes temperature uniformity. Accordingly, pursuant to the discussion above, a typical heat cycle using a movable hearth would be as follows: ______________________________________HEAT CYCLE ConvectiveHearth Work Heat TransferPosition Temperature (Fan Speed) Pressure______________________________________Centered 70°-500° F. High Atmospheric to Positive PressuresCentered 500°-1000° F. Medium Slight Sub-AtmosphericRaised 1000°-Final None Soft Vacuum Heat (Slow Fan Rotation)______________________________________ In the heat cycle depicted above, the fan would rotate at high speeds to achieve fast convection heat transfer with the furnace chamber at positive pressure as set forth in Surface's '091 patent. As the work begins to heat, the fan speed is reduced and a very slight negative pressure is pulled in the furnace chamber from a vacuum pump (not shown), i.e. 30 inches of water column. At this slight negative pressure, convection can still occur, but at a reduced rate while heating by the radiant tubes becomes more pronounced. However, the work still remains vertically centered within furnace chamber 28. Once this transition stage is completed, the soft vacuum is pulled and the hearth is raised to its FIG. 11 position to achieve good temperature uniformity by radiation. For such applications, the fan would have to be constructed of high temperature materials (conventional high temperature fans are available) and the fan would have to continue rotating even during final heating to avoid blade wrappage. A conventional microprocessor 200, illustrated schematically in FIG. 11 is used to coordinate and control the speed of the fan (not shown but shown and described in '091); the position of hearth 120; the pressure within furnace chamber 28 by means of a conventional vacuum pump (not shown) and all functions would be controlled depending upon the temperature of the work 120 measured by conventional means such as a thermocouple or pyrometer (not shown). The pump, high speed fan, thermocouple, etc. are all conventional items readily available to the trade and are not shown or described in detail herein. A baffle plate 201 as more fully described in the '091 patent is spaced adjacent one axial end of furnace chamber 28 and radiant tubes 125, 126, 128, 129 extend within the annular space between baffle plate 201 and the interior of the furnace casing. Fan blade 202 is shown in phantom lines behind work 120. The invention has been described with reference to a preferred embodiment and at least one alternative embodiment. Obviously, modifications and alterations will occur to those skilled in the art upon reading and understanding the description of the invention set forth herein. It is intended to include all such modifications and alterations insofar as they come within the scope of the invention.
A standard atmosphere furnace constructed of a steel casing formed as a cylinder with fibrous insulation attached is operated as a vacuum furnace. A plurality of radiant, fuel-fired ceramic heat tubes positioned in a centered but circumferentially spaced arrangement provides heat input to the furnace to permit it to operate at high, vacuum associated temperatures. The ceramic tubes are vacuum sealed to the furnace case by an elastomer seal/water jacket arrangement which uses an outboard clamp arrangement to establish a ceramic-to-metal contact to permit thermal cooling and prevent tube-flange movement so that the integrity of the elastomer seal can be maintained. In addition, an articulated joint connector is provided so that the tube can be supported in a pivotable manner permitting thermal movement while reducing tube stress to prolonged tube life.
5
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight module used in a liquid crystal display, and more particularly, to a backlight module with a brightness enhancement film having a plurality of spherical surface microlenses. 2. Description of the Related Art A backlight module is a key component of a liquid crystal display (LCD). The purpose of the backlight module is to provide a sufficient-brightness and an even-distribution light surface to the LCD panel. Because the LCD is widely used in various electronic products such as a monitor, a notebook computer, a digital camera, and a projector, the demand for the backlight module has increased tremendously. Please refer to FIG. 1 , which shows a prior art of a backlight module 20 . The backlight module 20 comprises a light source 22 (such as a cold cathode fluorescent lamp, a hot cathode fluorescent lamp, a light emitting diode), a light guide plate 26 , a reflector 24 disposed at a side of the light guide plate 26 , a diffusion sheet 28 , and prism sheets 30 and 32 . The reflector 24 is used for reflecting light from the light source 22 toward the light guide plate 26 . Then the light guide plate 26 guides light emitted from the light source 22 and light reflected from the reflector 24 as uniform planar light. Through the light-distributing of the diffusion sheet 28 and light-gathering of the prism sheets 30 and 32 , the light is fed into an LCD panel. The prism sheets 30 and 32 are formed by hardening an acrylic resin on a polyester film with a thickness of 125-μm by means of exposure under high energy UV light. The conventional prism sheets 30 and 32 are served as bar-alignment triangle prisms in characteristics of a vertex angle of substantial 90 degrees with an interval of 50 μm within each other. The prism sheets 30 and 32 can concentrate scatter light from the light guide plate 26 upward with substantial ±35 degrees with respect to a direction of an on-axis. Nevertheless, as shown in FIG. 1 , the prism sheet 30 only concentrate light constituent of Y-axis upward, and the prism sheet 32 only concentrate light constituent of X-axis upward. Therefore, utilizing only a single prism sheet can enhance the brightness by 1.6 times, while, for better light-gathering quality, utilizing two prism sheets 30 and 32 with their prism alignments thereon being vertical to each other can enhance the brightness by 2 times or more. In other words, scatter light is gathered by means of prisms on the prism sheets 30 and 32 , therefore boosting the brightness of the LCD display by 2 times. In this manner, for the LCD display described above, power consumption is lowered and a life span of batteries is lengthened. Consequently, using a single prism sheet fails to provide sufficient brightness, while using two prism sheets may result in more photo-energy consumption. Besides, using two prism sheets may induce higher cost for the backlight module as a result. SUMMARY OF THE INVENTION An objective of the present invention is to provide a backlight module comprising a brightness enhancement film with a plurality of spherical surface microlenses in lieu of a backlight module having two conventional prism sheets to solve the problem existing in prior art. Briefly summarized, the invention provides a backlight module comprising a light source, a light guide plate for guiding light from the light source, and a brightness enhancement film comprising a plurality of spherical surface microlenses for gathering light from the light guide plate. It is an advantage of the present invention that using one brightness enhancement film with a plurality of spherical surface microlenses thereon in lieu of the conventional structure of two prism sheets. The scatter light from the light guide plate can be concentrated toward a direction of an on-axis by the spherical surface microlenses, solving the conventional defect of needing to use two prism sheets to concentrate light. The disclosed inventions will be described with references to the accompanying drawings, which show important example embodiments of the inventions and are incorporated in the specification hereof by related references. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a conventional backlight module. FIG. 2 shows a backlight module according to an embodiment of the present invention. FIG. 3 is an enlarged view of a first embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 4 is a side view of the first embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 5 is an enlarged view of a second embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 6 is a side view of the second embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 7 is an enlarged view of a third embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 8 is a side view of the third embodiment of the brightness enhancement film depicted in FIG. 2 . FIG. 9 is a schematic illustration showing light passing through a brightness enhancement film and a light guide plate. FIGS. 10A-10I illustrate a flow forming the brightness enhancement film according to the present invention. FIG. 11 shows an appearance of the first photoresist and the second photoresist to be heated after a period of time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Please refer to FIG. 2 , which shows a backlight module 50 in accordance with the present invention. The backlight module 50 comprises a light source 52 (such as a cold cathode fluorescent lamp, a hot cathode fluorescent lamp, a light emitting diode), a light guide plate 56 , a reflector 54 disposed at a side of the light guide plate 56 , and a brightness enhancement film 60 . The reflector 54 is used for reflecting light from the light source 52 toward the light guide plate 56 . The light guide plate 56 guides light emitted from the light source 52 and light reflected from the reflector 54 and distributes the light as a uniform planar light source. Through the light-distributing of the diffusion sheet 58 and light-gathering of the brightness enhancement film 60 , the light is fed into an LCD panel. In FIG. 2 , the diffusion sheet 58 is preferably disposed between the brightness enhancement film 60 and the light guild plate 56 . In other embodiments, either disposing the diffusion sheet 58 over the brightness enhancement film 60 , or no diffusion sheet arrangement is also allowed. Please refer to FIG. 3 to FIG. 8 . FIG. 3 and FIG. 4 , respectively, are an enlarged view and a side view of a first embodiment of the brightness enhancement film 60 depicted in FIG. 2 . The brightness enhancement film 60 comprises a plurality of spherical surface microlenses 62 a and a plurality of carriers 64 a . Each spherical surface microlens 62 a is disposed on corresponding one of the plurality of carriers 64 a . Each of the plurality of carriers 64 a is closely disposed with each other. The plurality of carriers 64 a are substantially shaped as triangles. FIG. 5 and FIG. 6 , respectively, are an enlarged view and a side view of a second embodiment of the brightness enhancement film 60 depicted in FIG. 2 . The brightness enhancement film 60 comprises a plurality of spherical surface microlenses 62 b and a plurality of carriers 64 b . Each spherical surface microlens 62 b is disposed on corresponding one of the plurality of carriers 64 b . Each of the plurality of carriers 64 b is closely disposed with each other. The plurality of carriers 64 b are substantially shaped as rectangles. FIG. 7 and FIG. 8 , respectively, are an enlarged view and a side view of a third embodiment of the brightness enhancement film 60 depicted in FIG. 2 . The brightness enhancement film 60 comprises a plurality of spherical surface microlenses 62 c and a plurality of carriers 64 c . Each spherical surface microlen 62 c is disposed on corresponding one of the plurality of carriers 64 c . Each of the plurality of carriers 64 c is closely disposed with each other. The plurality of carriers 64 c are substantially shaped as hexagons. A resolution for better light-gathering performance is to increase a thickness of the carriers 64 a , 64 b or 64 c , or cushioning the carriers 64 a , 64 b or 64 c with another carrier to obtain a higher ratio of height and width (h/w) of the brightness enhancement film 60 . Referring to FIG. 9 , the spherical surface microlenses 62 can refract any light constituents from the light guide plate 56 upward. Please refer to FIGS. 10A-10I , which illustrate a flow of forming the brightness enhancement film according to the present invention. First of all, as shown in FIG. 10A , a first photoresist 210 (e.g. Az9260) is spread on a substrate 200 in a spin-coating manner. Next, a second photoresist 220 (e.g. AZ4620) is also spread evenly on the first photoresist 210 in a spin-coating manner. It is appreciated that melting point of the first photoresist 210 should be higher than that of the second photoresist 220 . Then, as shown in FIG. 10B , etching the first photoresist 210 and the second photoresist 220 are performed to form an array pattern. As can be seen in FIG. 10C , in a process of reflowing the first photoresist 210 and the second photoresist 220 , due to the fact that the melting point of the first photoresist 210 is higher than that of the second photoresist 220 , it happens that the first photoresist 210 is not completely melted but the second photoresist 220 has already melted. In doing so, the melted second photoresist 220 forms a half-sphere due to surface tension as the first photoresist 210 does not melt completely. As shown in FIG. 10D , sputtering a nickel film 230 on the first photoresist 210 and the second photoresist 220 is executed after cooling the photoresists 210 and 220 . Next, electroplating a Ni—Co film 240 on the nickel film 230 and sputtering an Au film 250 on the Ni—Co film 240 are illustrated in FIG. 10E . Furthermore, the first photoresist 210 and the second photoresist 220 , covering with metal films 230 , 240 , 250 , are electroformed to form a cast 260 , as shown in FIGS. 10F and 10G Finally, a metal mold 270 is obtained by re-electroforming the cast 260 . Accordingly, a mass production of the brightness enhancement film 60 with a plurality of spherical surface microlenses is possible by injecting plastic material 280 such as polyester or polycarbonate into the metal mold 270 , as shown in FIGS. 10H and 10I . Preferably, spherical surface microlens 62 a , 62 b , and 62 c are substantially shaped as spheres. However, in real process of forming the metal mold 270 , the appearance of the melted second photoresist 220 , due to incomplete melt of the first photoresist 210 , is as shown in FIG. 11 , rather than a half-sphere. As a result, the appearance of the spherical surface microlenses of the brightness enhancement film 60 made by the metal mold 270 is similar to the appearance shown in FIG. 11 . In contrast to prior art, the present inventive backlight module uses a brightness enhancement film with a plurality of spherical surface microlenses thereon in lieu of the conventional structure of two prism sheets. The scatter light from the light guide plate can be concentrated toward a direction of an on-axis by the spherical surface microlenses, solving the defect of the use of two prism sheets. In addition, the present inventive brightness enhancement film has the function of light-gathering and light-distributing. Since the light only passes through a single brightness enhancement film, photo energy consumption is reduced. Therefore, the use of the present inventive brightness enhancement film not only lowers costs, but also reduces power consumption. The present invention has been described with references to certain preferred and alternative embodiments which are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims.
A backlight module includes a light source, a light guide plate for guiding light from the light source, and a brightness enhancement film having a plurality of spherical surface microlenses for gathering light from the light guide plate. In contrast to traditional prism sheets, the brightness enhancement film having the plurality of spherical surface microlenses have better efficiency of light-gathering.
6
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to an optical pickup apparatus which emits a plurality of laser beams of different wavelengths and can read recorded information from a plurality of kinds of optical discs of different recording densities. [0003] 2. Description of the Related Art [0004] Generally, a semiconductor laser device is used as a light source of an optical pickup apparatus for playing an optical information recording medium such as CD, DVD, or the like. [0005] To play back the recording medium, the light emission wavelength and the numerical aperture (NA) of an objective lens of the semiconductor laser device which is used for playing a CD and for playing a DVD are different from each other. For example, in the case of the DVD, the wavelength is equal to 650 nm and the NA is equal to 0.6 and, in the case of the CD, the wavelength is equal to 780 nm and the NA is equal to 0.45. [0006] To play different kinds of discs such as CD and DVD by one disc player, therefore, an optical pickup apparatus having therein light sources of two wavelengths of 650 nm and 780 nm is being used. FIG. 1 shows an example of the optical pickup apparatus. [0007] According to the optical pickup apparatus shown in FIG. 1 , a laser device 1 for emitting a laser beam having a wavelength of 650 nm, a laser device 2 for emitting a laser beam having a wavelength of 780 nm, a synthesizing prism 3 , a half mirror 4 , a collimator lens 5 , and an objective lens 6 are sequentially arranged. Further, a cylindrical lens (not shown) and a photodetector 7 are placed on another optical axis which is branched from the half mirror 4 . In the construction, since an optical system starting with the synthesizing filter 3 and extending to an optical disc 8 is used in common for the CD and DVD, in both cases, the light emitted from the laser device passes through the synthesizing filter 3 and, thereafter, is guided toward the optical disc 8 along an optical axis Y. The objective lens 6 used here is a lens having double focal points and different focal positions, provided in accordance with the two wavelengths. A spherical aberration which is caused by different thicknesses of surface substrates of the CD and DVD can be, consequently, suppressed. [0008] In the construction, however, since a synthesizing prism or the like is needed, a large number of parts is required and production costs are high. Further, because it is necessary to match the positions of the two laser devices and the synthesizing prism, the construction becomes complicated, and it is difficult to make adjustments to the device. SUMMARY OF THE INVENTION [0009] In consideration of the problems, it is an object of the present invention to provide an optical pickup apparatus in which a construction of the apparatus for using a plurality of laser beams having different wavelengths can be simplified and miniaturized. [0010] According to the present invention, there is provided an optical pickup apparatus comprising: a light emitting device having at least a first light source for emitting a first laser beam and a second light source for emitting a second laser beam having a wavelength different from that of the first laser beam and in which the first and second light sources are closely arranged; an optical system formed with an irradiation optical path for guiding the laser beam toward a recording medium and a reflection optical path for guiding a reflected laser beam by the recording medium toward a photodetector; and a holding member for holding optical parts of the optical system, wherein on the irradiation optical path near an arranging position of the light emitting device, the optical system includes a first grating for allowing the first laser beam to pass as a 0th order light, diffracting the second laser beam, and generating a primary diffracted light having an optical axis which closely coincides with an optical axis of the first laser beam and a second grating for using the laser beam supplied from the first grating as a main beam and generating sub-beams for generating a tracking error signal according to a three-beam method with respect to the main beam, and the holding member holds a unit in which the light emitting device and the first and second gratings are integrated. [0011] According to the invention, there is provided an optical pickup apparatus comprising: a light emitting device having at least a first light source for emitting a first laser beam and a second light source for emitting a second laser beam having a wavelength different from that of the first laser beam and in which the first and second light sources are closely arranged; an optical system formed with an irradiation optical path for guiding the laser beam toward a recording medium and a reflection optical path for guiding a reflected laser beam by the recording medium toward a photodetector; and a holding member for holding optical parts of the optical system, wherein on the irradiation optical path near an arranging position of the light emitting device, the optical system includes a brazed hologram device for allowing the first laser beam to pass as a 0th order light, diffracting the second laser beam, and generating a primary diffracted light, as a main beam, having an optical axis which closely coincides with an optical axis of the first laser beam, and the holding member holds a unit in which the light emitting device and the brazed hologram device are integrated. [0012] According to the invention, there is provided a semiconductor laser unit for an optical pickup apparatus, comprising: a light emitting device having at least a first light source for emitting a first laser beam and a second light source for emitting a second laser beam having a wavelength different from that of the first laser beam and in which the first and second light sources are closely arranged; a first grating for allowing the first laser beam to pass as a 0th order light, diffracting the second laser beam, and generating a primary diffracted light having an optical axis which closely coincides with an optical axis of the first laser beam; a second grating for using the laser beam supplied from the first grating as a main beam and generating sub-beams for generating a tracking error signal of a three-beam method with respect to the main beam; and a holding member for holding the light emitting device and the first and second gratings in an integrated form. [0013] According to the present invention, there is provided a semiconductor laser unit for an optical pickup apparatus, comprising: a light emitting device having at least a first light source for emitting a first laser beam and a second light source for emitting a second laser beam having a wavelength different from that of the first laser beam and in which the first and second light sources are closely arranged; a brazed hologram device for allowing the first laser beam to pass as a 0th order light, diffracting the second laser beam, and generating a primary diffracted light, as a main beam, having an optical axis which closely coincides with an optical axis of the first laser beam; and a holding member for holding the light emitting device and the brazed hologram device in an integrated form. BRIEF DESCRIPTION OF THE DRAWINGS [0014] [0014]FIG. 1 is a constructional diagram showing an example of a conventional optical pickup apparatus; [0015] [0015]FIG. 2 is a diagram showing an optical system of an optical pickup apparatus as an embodiment of the present invention; [0016] [0016]FIG. 3 is a diagram showing a cross section of a hologram device in the optical system of FIG. 2; [0017] [0017]FIGS. 4A and 4B are diagrams showing position adjustment of a spot light according to a three-beam method in the apparatus of FIG. 1; [0018] [0018]FIG. 5 is a cross sectional view showing details of a semiconductor laser device; [0019] [0019]FIG. 6 is a diagram showing a pattern on a photosensing surface of a photodetector in the apparatus of FIG. 1; [0020] [0020]FIG. 7 is a diagram showing a cross section of another hologram device and its operation; and [0021] [0021]FIG. 8 is a diagram showing a cylindrical holder portion of an optical pickup apparatus according to another embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0022] An embodiment of the invention will now be described in detail hereinbelow with reference to the drawings. [0023] [0023]FIG. 2 shows an optical system of an optical pickup apparatus according to the present invention. In the optical pickup apparatus, a semiconductor laser device 11 for emitting two laser beams of different wavelengths and a hologram device 12 for diffracting the laser beam are attached to a cylindrical holder 13 and integrated. The cylindrical holder 13 is hollow and has opening portions at both ends. The semiconductor laser device 11 is fixed to one of the opening portions of the cylindrical holder 13 . The hologram device 12 is fixed to the other opening portion of the cylindrical holder 13 . [0024] The semiconductor laser device 11 individually emits a first laser beam having a wavelength of 650 nm and a second laser beam having a wavelength of 780 nm from different light emitting points which are arranged toward a same emitting direction. An interval L between the light emitting points is equal to about 100 μm. [0025] As shown in FIG. 3, the hologram device 12 has a first grating 12 a and a second grating 12 b . The first grating 12 a is brazed and formed on one of the surfaces of a substrate of the hologram device 12 , that is, on the surface locating on the side of the semiconductor laser device 11 and diffracts the second laser beam so that an optical axis of a primary diffracted light of the second laser beam of the wavelength of 780 nm coincides with an optical axis of a 0th order light of the first laser beam of the wavelength of 650 nm. That is, one of the 0th order light of the first laser beam which passed through the first grating 12 a and one of ± primary diffracted lights (having positive and negative polarities) of the second laser beam is used as a main beam (beam for reading information) which is irradiated onto a disc 17 . As shown in FIG. 3, the brazed hologram is a hologram on which a sawtooth-shaped grating has been formed and can set a ratio of positive and negative light amounts of high-order diffracted light in accordance with an angle of inclination of the saw teeth. In the embodiment, use efficiency of the second laser beam is improved by setting the inclination angle so that the amount of light which is used as a main beam of the ± primary diffracted lights of the second laser beam becomes larger. [0026] The second grating 12 b is formed on the other surface of the substrate of the hologram device 12 , that is, on the surface locating on the side of a half mirror 14 , which will be explained hereinlater, diffracts the primary light of the second laser beam of the wavelength of 780 nm, and newly emits ± primary diffracted lights. The ± primary diffracted lights are used for generating a tracking error signal. [0027] In the case of attaching the semiconductor laser device 11 and hologram device 12 to the cylindrical holder 13 , the semiconductor laser device 11 is fixedly bonded to the cylindrical holder 13 with an adhesive agent (not shown). The hologram device 12 is rotated so that the optical axis of the primary diffracted light of the second laser beam of the wavelength of 780 nm coincides with the optical axis of the first laser beam of the wavelength of 650 nm, and is positioned against the semiconductor laser device 11 . After that, the hologram device 12 is fixedly bonded to the cylindrical holder 13 with the adhesive agent. It is also possible to use a method whereby the hologram device 12 is previously fixed to the cylindrical holder 13 , the semiconductor laser device 11 is rotated in order to position against the hologram device 12 , and after that, the hologram device 12 is fixed to the cylindrical holder 13 . [0028] In the case of performing a tracking servo control by the three-beam method, the positions of three spot lights formed on a disc are adjusted by rotating the cylindrical holder 13 to an optical pickup apparatus body 19 . That is, an attaching hole 20 for supporting the cylindrical holder 13 is formed in the body 19 of the optical pickup apparatus. The cylindrical holder 13 is rotatable in the attaching hole 20 before being fixedly bonded with the adhesive agent. The cylindrical holder 13 to which the semiconductor laser device 11 and hologram device 12 have been fixed is inserted into the attaching hole 20 . As shown in FIG. 4A, according to the position adjustment of the three spot lights, three circular spot lights S 1 to S 3 are formed onto a track T of the disc. A center of each of the spot lights S 1 to S 3 is located on a straight line SL connecting them. The spot light S 1 is a spot light of the main beam. In the tracking servo control by the three-beam method, the spot lights S 2 and S 3 of sub-beams are used so that the spot light S 1 is located at the center of the track T. By rotating the cylindrical holder 13 , an angle θ formed by the straight line SL and track T (accurately, a tangential line of the track T) can be varied as shown in FIG. 4B. By the position adjustment of the spot lights, for example, the spot lights S 2 and S 3 are located almost on a mirror surface of the disc so as to slightly include the track T. At this time, since the relative positional relation among the light emitting points of the first and second laser beams and the first grating 12 a and second grating 12 b is always maintained, a deviation is not caused in the relation between the 0th order light of the first laser beam and the primary light of the second laser beam by the rotation adjustment. By making the rotational center of the cylindrical holder 13 coincide with the center of the spot light S 1 , the position adjustment can be easily performed. After the position adjustment of the spot lights, the cylindrical holder 13 is fixed to the optical pickup apparatus body 19 with, for example, the adhesive agent. [0029] In the optical system of the optical pickup apparatus, the half mirror 14 reflects the laser beam which passed through the hologram device 12 . The laser beam reflected by the half mirror 14 reaches a disc 17 while sequentially passing through a collimator lens 15 and an objective lens 16 . The collimator lens 15 converts the laser beam from the half mirror 14 into a parallel light and supplies it to the objective lens 16 . The objective lens 16 is a double-focal-point lens and converges the laser beam as a parallel light onto the recording surface of the disc 17 . A DVD and a CD (including a CD-R) are used as a disc 17 . One of those discs is loaded onto a turntable (not shown). [0030] The laser beam reflected by the recording surface of the disc 17 is converted into a parallel light laser beam by the objective lens 16 , is converted into the converged laser beam by the collimator lens 15 , and passes through the half mirror 14 while being slightly refracted. The laser beam which passed through the half mirror 14 reaches a photodetector 18 . [0031] Optical parts such as half mirror 14 , collimator lens 15 , and photodetector 18 are fixed to the body 19 as a holding member. Although not shown in FIG. 2, the objective lens 16 is movably fixed to the body 19 of the optical pickup apparatus through a focusing actuator and a tracking actuator (both are not shown). Although the body 19 of the optical pickup apparatus is segmentally illustrated in FIG. 2, the body 19 is a single body. [0032] [0032]FIG. 5 shows a cross section of a chip of the semiconductor laser device 11 . As shown in FIG. 5, the semiconductor laser device 11 is a monolithic type formed as one chip. A first light emitting unit 31 having a first light emitting point A 1 for emitting the first laser beam of a wavelength of 650 nm and a second light emitting unit 32 of a second light emitting point A 2 for emitting the second laser beam of a wavelength of 780 nm are formed on one of principal surfaces of a single n-type GaAs substrate 30 through a separating groove 33 . Each of the first light emitting unit 31 and second light emitting unit 32 have a laminated structure as will be explained hereinlater. A back electrode 34 serving as a common electrode of both light emitting units 31 and 32 is formed on the other principal surface of the substrate 30 . The light emitting surface of the first light emitting unit 31 having the light emitting point A 1 and the light emitting surface of the second light emitting unit 32 having the emitting point A 2 are directed in the same emitting direction. [0033] The first light emitting unit 31 has an n-type AlGaInP clad layer 41 , a strain quantum well active layer 42 , a p-type AlGaInP clad layer 43 , an n-type GaAs layer 44 , a p-type GaAs layer 45 , and an electrode 46 in order from the GaAs substrate 30 . A center portion of a cross section of the clad layer 43 is formed in a trapezoidal shape. The n-type GaAs layer 44 is formed so as to cover the clad layer 43 excluding the trapezoidal top surface. A p-type GaInP layer 47 is formed on the trapezoidal top surface. The first light emitting point A 1 is located on the strain quantum well active layer 42 . [0034] The second light emitting unit 32 has what is called a double hetero structure. A pair of n-type AlGaAs buried layers 51 and 52 are arranged on the GaAs substrate 30 with a predetermined gap. One electrode 55 is provided over the pair of n-type AlGaAs buried layers 51 and 52 through insulating layers 53 and 54 . An n-type AlGaAs clad layer 56 , an undoped GaAs active layer 57 , and a p-type AlGaAs clad layer 58 are sequentially laminated on the GaAs substrate 30 between the buried layers 51 and 52 . The clad layer 58 is in contact with the electrode 55 . The second light emitting point A 2 is located in the active layer 57 . An interval between the optical axis from the first light emitting point A 1 and the optical axis from the second light emitting point A 2 is equal to, for example, 100 μm. [0035] The semiconductor laser device 11 is fixed into an insulating sub mount and they are further covered by a casing member 11 a as shown in FIG. 2. [0036] The semiconductor laser device 11 is driven by a laser driving circuit (not shown). The laser driving circuit drives the semiconductor laser device 11 so as to selectively emit either the first laser beam or the second laser beam in accordance with a kind of disc 17 from which recorded information should be read. That is, the laser driving circuit drives the semiconductor laser device 11 so as to selectively emit the first laser beam of the wavelength of 650 nm when the disc 17 is a DVD. The laser driving circuit drives the semiconductor laser device 11 so as to selectively emit the second laser beam of the wavelength of 780 nm when the disc 17 is a CD. [0037] As shown in FIG. 6, the photosensing surface of the photodetector 18 includes three square areas T 1 , M, and T 2 and these areas are arranged in a line in the same plane in that order. The area M is positioned between the areas T 1 and T 2 and divided into four parts crosswise. The divided parts are formed by photosensitive devices 18 a to 18 d . Photosensing surfaces of the photosensitive devices 18 a and 18 d are symmetrical around a dividing cross point as a center. Photosensing surfaces of the photosensitive devices 18 b and 18 c are symmetrical around a dividing cross point as a center. The areas T 1 and T 2 are tracking areas of the three-beam method and formed by photosensitive devices 18 e and 18 f. [0038] In the optical system of the optical pickup apparatus according to the invention shown in FIG. 2, when the disc 17 is a DVD, the semiconductor laser device 11 emits a first laser beam (solid line in FIG. 2) of the wavelength of 650 nm by the selective driving of the laser driving circuit. A 0th order light of the first laser beam passes through the first grating 12 a and second grating 12 b of the hologram device 12 as it is and reaches the half mirror 14 . The 0th order light of the first laser beam reflected by the half mirror 14 reaches the disc 17 through the collimator lens 15 and objective lens 16 . The 0th order light of the first laser beam reflected by the recording surface of the disc 17 reaches the area M of the photosensing surface of the photodetector 18 through the objective lens 16 , collimator lens 15 , and half mirror 14 . [0039] A read signal RF, a tracking error signal TE, and a focusing error signal FE are generated in accordance with output signals of the photosensitive devices 18 a to 18 d , respectively. Assuming that the output signals of the photosensitive devices 18 a to 18 d are set to a, b, c, and d in order, respectively, the read signal RF is calculated as follows: RF= a+b+c+d. [0040] The tracking error signal TE is calculated by a phase difference method as follows: TE=( a′+d′ )−( b′+c′ ). [0041] Reference characters a′, b′, c′, and d′ denote signals calculated by phase comparing the signals a, b, c, and d with the read signal RF. [0042] The focusing error signal FE is calculated by an astigmatism method as follows: FE=( a+d )−( b+c ). [0043] The read signal RF, focusing error signal FE, and tracking error signal TE are generated by an arithmetic operating circuit (not shown). [0044] When the disc 17 is a CD, the semiconductor laser device 11 emits a second laser beam (broken line in FIG. 2) of the wavelength of 780 nm by the selective driving of the laser driving circuit. The second laser beam is diffracted by a diffracting operation of the first grating 12 a of the hologram device 12 in a manner such that a + primary light becomes maximum and its optical axis coincides with the optical axis of a 0th order light of the first laser beam. When the + primary light of the second laser beam becomes the main beam and reaches the second grating 12 b of the hologram device 12 , ± primary lights regarding the + primary light of the second laser beam are generated due to the diffracting operation by the second grating 12 b . The ± primary lights are used as sub-beams for tracking of the three-beam method. [0045] The second laser beam which passed through the hologram device 12 is reflected by the half mirror 14 and, thereafter, reaches the disc 17 through the collimator lens 15 and objective lens 16 . Each order light of the second laser beam reflected by the recording surface of the disc 17 reaches the areas T 1 , M, and T 2 of the photosensing surface of the photodetector 18 through the objective lens 16 , collimator lens 15 , and half mirror 14 . That is, the main beam of the second laser beam forms the spot light onto the area M and the tracking sub-beams form spot lights onto the areas T 1 and T 2 , respectively. [0046] The read signal RF and focusing error signal FE are generated in accordance with the output signals of the photosensitive devices 18 a to 18 d . The tracking error signal TE is generated in accordance with the output signals of the photosensitive devices 18 e to 18 f . Assuming that the output signals of the photosensitive devices 18 a to 18 f are set to a to f in order, the read signal RF is calculated as follows: RF= a+b+c+d. [0047] The tracking error signal TE is calculated by the three-beam method as follows: TE= e−f. [0048] The focusing error signal FE is calculated by the astigmatism method as follows: FE=( a+d )−( b+c ). [0049] In the embodiment, the hologram device 12 is not limited to the device having the first and second gratings 12 a and 12 b as shown in FIG. 3. For example, as shown in FIG. 7, a brazed hologram device 21 can be used. A saw-tooth-shaped grating 21 a is formed on one of the surfaces of the brazed hologram device 21 . In the optical system, the grating 21 a is located on the half mirror 14 side. Although a first laser beam of the wavelength of 650 nm is not diffracted by the grating 21 a , a second laser beam of the wavelength of 780 nm is diffracted. As shown in FIG. 7, a + primary diffracted light of the second laser beam becomes maximum, its optical axis is made to coincide with the optical axis of the first laser beam, and this + primary diffracted light becomes the main beam. A 0th order light and a + secondary diffracted light of the second laser beam are diffracted in order to use them as tracking sub-beams of the three-beam method. A light amount of each of the 0th order light and the + secondary diffracted light is set to almost the same level in the brazed hologram device 21 and to be lower than that of the + primary diffracted light. [0050] In the embodiment shown in FIG. 2, the hologram device 12 is directly fixed to the cylindrical holder 13 . As shown in FIG. 8, however, it is also possible to construct the apparatus in a manner such that the hologram device 12 is fixedly bonded to a hologram holder 22 and attached thereto, the semiconductor laser device 11 and hologram device 12 are mutually positioned by rotating the hologram holder 22 including the hologram device 12 so that the optical axis of the primary diffracted light of the second laser beam of the wavelength of 780 nm coincides with the optical axis of the first laser beam of the wavelength of 650 nm, and thereafter, the hologram holder 22 is fixedly bonded to the other opening portion of the cylindrical holder 13 and attached thereto. [0051] According to the invention as mentioned above, the optical pickup apparatus can be formed in a compact size. Further, the tracking servo control can be stably performed by merely making the simple adjustment. [0052] This application is based on a Japanese Patent Application No. 2000-250676 which is hereby incorporated by reference.
An optical pickup apparatus has a first light source for emitting a first laser beam, a second light source for emitting a second laser beam whose wavelength is different from that of the first laser beam, a first grating for allowing the first laser beam to pass as a 0th order light, diffracting the second laser beam, and generating a primary diffracted light having an optical axis which closely coincides with that of the first laser beam, and a second grating for using the laser beam supplied from the first grating as a main beam and generating sub-beams for generating a tracking error signal of a three-beam method with respect to the main beam, wherein the first and second light sources and the first and second gratings are constructed as an integrated unit, and the unit is held in a holding member for holding the optical parts of the optical system.
6
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to portable transceivers such as cellular type mobile radio telephones which are driven by a battery power source to transmit and receive data on a plurality of channels (a plurality of frequencies) in a radio broadcasting manner and which have a function of stabilizing a consumption current and more particularly, to a portable transceiver which can average the quantities of currents different with respect to used channels and thus can maintain substantially the same power consumption in the battery power source with respect to the different channels even when any of the channels is used. 2. Description of the Related Art FIG. 6 schematically shows a block diagram of an arrangement of the final stage of a prior art portable radio transceiver. The radio transceiver of FIG. 6 includes a power amplifier 1, an isolator 2, and an antenna 3. In operation, a signal 100 generated as a transmission signal at the previous stage of the transceiver is amplified with respect to power at the power amplifier 1, sent via the isolator 2 to the transmitting antenna 3, and then radiated from the antenna 3 in the form of transmission waves (electromagnetic waves). Meanwhile it is known that the impedance of the above isolator 2 varies depending on the frequency of its input signal. More specifically, the isolator 2 has such a characteristic that the higher the frequency of the input signal is the larger the capacity is, and conversely the lower the frequency of the input signal is the larger the inductance is. The consumption current of the power amplifier 1 varies with the impedance of a load connected thereto and when the load has a large capacitive impedance, the power amplifier 1 has a small output current and thus requires a small consumption current. Conversely, when the load has a small capacitive impedance or a large inductive impedance, the power amplifier 1 requires its relatively large output current and thus a large consumption current. Accordingly, in the case where such a portable radio transceiver transmits signals having a plurality of frequencies through channel switching operation: (a) when the transceiver transmits a signal having a relatively high frequency through corresponding selected one (frequency) of the channels, the isolator 2 connected to the power amplifier 1 as its load has a large capacitive impedance, whereby the consumption current of the power amplifier 1 is suppressed to a low level and therefore the power consumption of the battery power source in the portable radio transceiver can be reduced. (b) When the radio transceiver transmits a signal having a relatively low frequency, the isolator 2 connected to the power amplifier 1 as its load has a small capacitive impedance or has a large inductive impedance, which results in that the consumption current of the power amplifier 1 becomes large and therefore the battery power source of the portable radio transceiver is quickly and much consumed. In this way, the consumption current of the power amplifier 1 and thus the power consumption of the battery power source (e.g., Ni-Cd battery) varies depending on the selected channel. For this reason, in such a portable radio transceiver, generally speaking, it is difficult in actual circumstances to prescribe a standard battery device in its specification. In addition, with respect to differences in the power consumption of the battery power source between the use channels, the power consumption of the battery power source when one of the channels having a higher frequency is selected can be maintained or sustained for a relatively long; whereas, when one of the channels having a lower frequency is frequently selected, the power of the battery power source can be consumed unexpectedly quickly, thus causing an undesirable communication failure and a user to be confused. SUMMARY OF THE INVENTION In view of such circumstances, it is an object of the present invention to provide a portable ratio transceiver having a consumption-current stabilizing function which can average quantities of consumption currents of a battery power source different depending on the selected channel (frequency) and thus can make substantially constant the power consumption of the battery power source between different channels to be selected even when the transceiver is selected at any one of the channels. In accordance with an aspect of the present invention, in order to attain the above object, as mentioned above, a load which impedance varies with the frequency of an input signal of a power amplifier is connected to the power amplifier, and a compensation circuit for cancelling and compensating for the impedance change of the load is also connected to the power amplifier, so that the compensation of the load impedance through the compensation circuit enables the consumption current of the power amplifier to be kept substantially constant regardless of changes in the impedance of the load itself. The compensation circuit may comprise, for example, control voltage generation means for outputting a high control voltage when a high frequency is selected and for outputting a low control voltage when a low frequency is selected according to the channel frequency, and a vari-cap diode (voltage variable capacitance diode) which impedance varies to have an decreased capacitive impedance when subjected to an application of the high control voltage generated from the control voltage generation means and to have an increased capacitive impedance when subjected to an application of the low control voltage thereof according to the control voltage applied thereto. In the case where such a compensation circuit having the aforementioned arrangement and function as the above is provided to the load side of the power amplifier, even when the selected channel frequency is high or low, the impedance of the power amplifier when viewed from the power amplifier, i.e., a combined impedance of the load such as the isolator and the compensation circuit can be kept substantially constant, which results in that the current consumption of the power amplifier can be also kept at a substantially constant rate regardless of the selected channel. Of course, this means that the power consumption of the battery power source for supplying power to the power amplifier, compensation circuit, etc. of the portable radio transceiver can be maintained substantially constant independently of the selected channel. As a result, such problems in the prior art portable radio transceiver that "it is difficult to prescribe a standard battery drive time in its specification" and that "the power consumption of the battery power source varies depending on the selected channel" which causes a user to be confused can be satisfactorily eliminated. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an arrangement of a portable radio transceiver having a consumption-current stabilizing function in accordance with an embodiment of the present invention; FIG. 2 is a graph showing control voltage/oscillation frequency characteristics of a second voltage-controlled oscillator shown in FIG. 1; FIG. 3 is a graph showing applied voltage/capacitance characteristics of a vari-cap diode (variable capacitance diode) shown in FIG. 1; FIG. 4 is a Smith chart showing an impedance characteristic of an isolator shown in FIG. 1; FIG. 5 is a current contour line diagram showing variations in a consumption current with respect to variations in the load impedance of a power amplifier shown in FIG. 1; and FIG. 6 is a block diagram of an arrangement of the final stage of a prior art portable radio transceiver. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, there is shown an embodiment of a portable radio transceiver having a consumption-current stabilizing function in accordance with an embodiment of the present invention. Even in FIG. 1, only the final stage of the portable radio transceiver is illustrated for convenience of explanation. The portable radio transceiver of the embodiment of FIG. 1 includes a power amplifier 1 for amplifying a transmission signal with respect to power, an isolator 2 which passes the transmission signal power-amplified at the power amplifier 1 in its only-one direction, an antenna 3 for radiating the transmission signal passed through the isolator 2 therefrom in the form of transmission waves, a vari-cap diode (voltage variable capacitance diode) 4 which capacitance varies with a voltage applied thereto, a capacitor 5 which is used to adjust the capacitance of an overall load including the isolator 2 and the vari-cap diode 4 when viewed from the power amplifier 1 and to connect the vari-cap diode 4 to a load side of the power amplifier 1 while the voltage applied to the vari-cap diode 4 does not affect the output of the power amplifier 1, a resistor 6 through which a voltage 200 is applied to the vari-cap diode 4 as its control voltage, a first voltage-controlled oscillator (first VCO) 7 for modulation, a second voltage-controlled oscillator (second VCO) 8 for determination of the frequency of the transmission signal, a mixer 9 for mixing an oscillation signal of the first VCO 7 and an oscillation signal of the second VCO 8, a buffer amplifier 10 for inputting a transmission output signal of the mixer 9 to the power amplifier 1, a channel selector 11 for generating various sorts of control voltages Vc to selectively switch the oscillation frequency (i.e., channel frequency) of the second VCO 8 in response to user's selecting operation, and a buffer amplifier 12 for applying the control voltage Vc generated at the channel selector 11 to the vari-cap diode 4 as the aforementioned control voltage 200. In the present embodiment, the control voltage Vc for channel frequency selection generated from the channel selector 11 is also used as the capacitance control voltage 200 of the vari-cap diode 4. In the illustrated example, the control voltage Vc as well as the oscillation frequency (channel frequency) of the second VCO 8 controlled by the control voltage satisfy such a relationship as shown in FIG. 2. More in detail, as shown in FIG. 2, the oscillation frequency of the second VCO 8 increases in proportion to the value of the control voltage Vc. In other words, when the aforementioned transmission signal has a low channel frequency, the control voltage Vc is set low so that the voltage 200 to be applied to the vari-cap diode 4 as its capacitance control voltage is also set low. Conversely, when the transmission signal has a high channel frequency, the control voltage Vc is set high so that the voltage 200 to be applied to the vari-cap diode 4 as its capacitance control voltage is also set high. This will be appreciated from FIG. 2. Meanwhile, the vari-cap diode 4 has such a characteristic that the capacitance of the vari-cap diode 4 is decreased as the capacitance control voltage 200 increases, while, the capacitance is increased as the control voltage 200 decreases. That is, the vari-cap diode 4 has such a characteristic showing a relationship between the control voltage 200 and the capacitance of the vari-cap diode 4 as shown in FIG. 3. Accordingly, it will be seen from FIGS. 2 and 3 that: (1) When the channel frequency of the transmission signal is low, the control voltage 200 is also low and thus the capacitance of the vari-cap diode 4 increases. (2) When the channel frequency of the transmission signal is high, the control voltage 200 is also high and thus the capacitance of the vari-cap diode 4 decreases. As already explained earlier, the isolator 2 has such an impedance characteristic that when the frequency of the input signal is high, the impedance of the isolator becomes capacitive, whereas, when the signal frequency is low, the impedance of the isolator becomes inductive. The characteristic of the isolator 2 is shown by a Smith chart in FIG. 4. In the drawing, a marker 1 denotes a signal which passes through the isolator 2, that is, a part of the transmission signal at which the frequency of the transmission signal is a minimum in its frequency band; while a marker 3 denotes a part of the transmission signal at which the frequency of the transmission signal is a maximum in the frequency band. It will be understood from the Smith chart that the isolator 2 has such a characteristic that the lower the frequency of the signal passing through the isolator is the larger the inductance is, whereas, the higher the signal frequency is the larger the capacitance is. In FIG. 4, a maker 2 denotes a center frequency in the aforementioned frequency band. As already explained earlier, the consumption current of the power amplifier 1 varies depending on the impedance of a load connected to the power amplifier 1. Such consumption current variation is shown in FIG. 5 in the form of a current contour line diagram. From FIG. 5, it will be appreciated that when the capacitive property of the load is stronger, the consumption current tends to decrease, whereas, when the capacitive property of the load is weaker or the inductive property thereof is stronger, the consumption current tends to increase. Numeral values in FIG. 5 denote exemplary values of the consumption current in the power amplifier 1 and the same value is shown as a contour line. Explanation will next be made as to the operation of the present embodiment, taking into consideration such characteristics of the vari-cap diode 4, isolator 2 and power amplifier 1 as mentioned above. When the portable radio transceiver is started, this causes power to be supplied from a battery power source (not shown) to such active elements in FIG. 1 as the power amplifier 1, first and second VCOs 7 and 8, buffer amplifiers 10 and 12, and channel selector 11. Now when the first VCO 7 generates a signal modulated with data to be transmitted, the generated signal is applied from the first VCO 7 to one input end of the mixer 9. On the other hand, the second VCO 8 generates a signal having a frequency corresponding to the control voltage Vc applied from the channel selector 11 and the generated signal is applied from the second VCO 8 to the other input end of the mixer 9. The output signals of the first and second VCOs 7 and 8 are mixed in the mixer 9 into a transmission signal having a predetermined channel frequency. Of course, the predetermined channel frequency corresponds to the frequency of the channel designated by the user through the channel selector 11. The thus-generated transmission signal is sent through the buffer amplifier 10 to the power amplifier 1, where the transmission signal is amplified to a predetermined power level and then sent to the isolator 2. The signal sent to the isolator 2 is further sent to the antenna 3, from which the signal is radiated in the form of electromagnetic waves, as already explained above. Even in the present embodiment, as stated above, the control voltage Vc for switching of the channel frequency generated at the channel selector 11 is also used as the capacitance control voltage 200 of the vari-cap diode 4, and the output frequency of the second VCO 8, i.e., the control voltage Vc controlling the channel frequency is also applied to the vari-cap diode 4 as its capacitance control voltage 200 through the buffer amplifier 12 and the resistor 6. It will be clear from the arrangement of FIG. 1 that the vari-cap diode 4 is connected through the capacitor 5 to the output of the power amplifier 1 as a second load of the power amplifier 1. That is, in the present embodiment, the load of the power amplifier 1 is made up of the isolator 2, vari-cap diode 4 and capacitor 5. And, as already explained above in conjunction with FIGS. 2 and 3: (1) When the channel frequency of the transmission signal is low, the control voltage 200 is also low and the capacitance of the vari-cap diode 4 increases. (2) When the channel frequency of the transmission signal is high, the control voltage 200 is also high and the capacitance of the vari-cap diode 4 decreases. As a result, the combination impedance of the aforementioned load when viewed from the power amplifier 1 is determined not only by the impedance characteristic (refer to FIG. 4) of the isolator 2 itself based on the frequency of the transmission signal but also by the capacitance of the vari-cap diode 4 controlled by the control voltage 200 (control voltage Vc). This results in: (A) When the selected channel frequency is low, that is, when the frequency of the transmission signal is low, the impedance of the isolator 2 itself varies in its smaller capacitive direction or in its larger inductive direction. At this time, the control voltage 200 is low and the capacitance of the vari-cap diode 4 increases, which results in that the combined load impedance is kept at a substantially averaged value because variations in the load impedances are cancelled each other. (B) When the selected channel frequency is high, that is, when the frequency of the transmission signal is high, the impedance of the isolator 2 itself varies in its larger capacitive direction. At this time, the control voltage 200 is high and the capacitance of the vari-cap diode 4 decreases, which results, even in this case, in that the combined load impedance is kept at a substantially averaged value because variations in the load impedances are cancelled each other. Such a phenomenon as mentioned above takes place at the load side of the power amplifier 1. Thus, even when such a channel frequency as mentioned above is selected or an intermediate frequency channel therebetween is selected, a variation in the load impedance when viewed from the power amplifier 1 can be satisfactorily suppressed. For this reason, fluctuations in the consumption current of the power amplifier 1 caused by the different transmission frequencies, which would occur in the prior art, can be suppressed so that it can be prevented that the power consumption of the battery power source varies depending on the selected channel frequency. In this way, in accordance with the present invention, the control voltage Vc of the second VCO 8 for channel selection is applied to the vari-cap diode 4 as the capacitance control voltage 200 and the vari-cap diode 4 is set to have such a characteristic as opposed to the impedance characteristic of the isolator 2 itself to thereby compensate for variations in the impedance of the isolator 2. As a result, variations in the consumption current of the power amplifier 1 can be suppressed and thus the power consumption of the battery power source can be substantially constant without being affected by the selected channel frequency. Although the compensation of the impedance variation of the isolator 2 can be realized basically by the capacitance variation of the vari-cap diode 4 itself in the circuit of the present invention, the degree of its compensation and how to compensate for it can be optimized by selecting the capacitance value of the capacitor 5 and the resistance value of the resistor 6. Further, the control voltage Vc for channel frequency selection generated from the channel selector 11 has been also used as the capacitance control voltage 200 of the vari-cap diode 4 in the present embodiment, but as means for generating the capacitance control voltage 200 of the vari-cap diode 4, such a microcomputer that recognizes the then-selected channel and controls the generation of a voltage corresponding thereto may be suitably employed, for example. Also, though the isolator has been used as a load which impedance varies with the frequency of the transmission signal in the foregoing embodiment, the present invention is not limited to the specific isolator as the load. That is, in accordance with the present invention, a variation in the impedance of any load exhibiting substantially the same impedance characteristic as mentioned above can be compensated for and thus fluctuations in the consumption current of the corresponding power amplifier can be suppressed.
A portable radio transceiver wherein an isolator which impedance varies usually with the frequency of a communication signal is connected to a power amplifier for power amplification of the communication signal as its load so that, when the frequency of the communication signal is changed through selection of the communication channel, the load impedance of the power amplifier is also changed and correspondingly the consumption current of the power amplifier is changed. In the portable radio transceiver, in order to suppress the change of the consumption current of the power amplifier, an impedance compensation circuit which impedance varies in its direction opposed to the isolator depending on the frequency of the communication signal is separately connected to the power amplifier, whereby changes in the impedance of the load side when viewed from the power amplifier can be substantially cancelled each other.
7
TECHNICAL FIELD This invention relates to a package in the form of an assembly of a container and removal-resistant closure thereon. BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART A common type of container has a threaded neck and is adapted to receive a threaded closure in the form of a cap or the like. In many applications, such a closure is initially applied to a container by an automatic closure applying apparatus, such as a high-speed capping machine. A variety of such threaded closures are provided with a dispensing feature, such as a lid body or base defining a dispensing orifice and a cooperating lid. The lid is disposed in the closure base and is adapted to be moved between (1) a lowered, closed position occluding the dispensing orifice and (2) an open position away from the dispensing orifice permitting the container contents to be discharged through the orifice. A number of these types of closure designs include tamper-evident features which must be broken in order to first move the lid from the closed portion to the open position. However, if the closure base itself is easily removable from the container, then a tamperer could gain access to the container interior even though the tamper-evident feature between the lid and closure base is not broken or disturbed. It would therefore be desirable in some applications to prevent the easy removal of the entire closure from the container-even for those closures which have no tamper-evident feature. Accordingly, it would be advantageous to provide an improved closure and container assembly wherein the closure cannot be easily removed. It would be especially desirable if such an improved design could be employed with a threaded system which would accommodate application of the closure to the container by means of a conventional, high-speed capping machine. In addition, it would be advantageous if such an improved design would permit the closure to turn freely or rotate on the container, in either direction, after the closure has been properly mounted to the container. This would provide an indication to the user that the closure cannot be removed by the normal unscrewing motion, and this would therefore discourage attempts to remove the closure. The present invention provides an improved container and mating closure system which can accommodate designs having the above-discussed benefits and features. SUMMARY OF THE INVENTION A package is provided according to the present invention which includes an assembly of a container and a removal resistant closure. The unique package permits the closure to be applied to the container with a conventional, high-speed capping machine. The closure is securely held on the container in a way that prevents or significantly inhibits manual removal. Nevertheless, the closure can rotate freely in either direction of rotation on the container. The container defines an opening, and the closure is applied to the container to occlude the opening. A suitable dispensing feature, such as a dispensing orifice and lid, can be provided in the closure. The container defines a first thread which extends at least partially around the container opening from a leading end to a trailing end. A second thread is defined by the closure and extends at least partially around the closure from a leading end to a trailing end. A projection is defined adjacent one of the first and second threads. The projection and one of the threads define a space between them which is less than the width of the other thread. The projection or the other thread, or both the projection and the other thread, are resilient to accommodate deformation during relative rotational movement of the container and closure when the container and closure are screwed together to mount the closure on the container. During this process, the threads are relatively axially displaced from a threadingly engaged condition to a disengaged condition which resists re-engagement. In a preferred embodiment, the first and second threads each includes a helical portion. Further, the container includes a third thread with a leading end, a helical portion, and a trailing end, while the closure includes a fourth thread with a leading end, a helical portion, and a trailing end. The projection is defined by the third thread trailing end on the container. The third thread trailing end has a smaller angle than the first thread helical portion and converges with the first thread helical portion to define the space which is less than the width of the closure second thread. In a typical application, the first and third threads on the container are each a male thread, and the second and fourth threads on the closure are each a female thread. In the preferred embodiment, an additional projection is defined on the container by the first thread trailing end adjacent the third thread helical portion. The first thread trailing end has a smaller angle than the third thread helical portion and converges with the third thread helical portion. The first thread trailing end and the third thread helical portion define a space between them which is less than the width of the closure fourth thread. Further, in the preferred embodiment, an additional projection is also defined by the fourth thread trailing end adjacent the second thread helical portion. The fourth thread trailing end has a smaller angle than the second thread helical portion and converges with the second thread helical portion. The fourth thread trailing end and the second thread helical portion define a space between them which is less than the width of the container first thread. Finally, in the preferred embodiment, an additional projection is also defined by the second thread trailing end adjacent the fourth thread helical portion. The second thread trailing end has a smaller angle than the fourth thread helical portion and converges with the fourth thread helical portion. The second thread trailing end and the fourth thread helical portion define a space between them which is less than the width of the container third thread. Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention, from the claims, and from the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings that form part of the specification, and in which like numerals are employed to designate like parts throughout the same. FIG. 1 is a fragmentary, perspective view of a preferred embodiment of the container and closure assembly of the present invention; FIG. 1A is a developed view of the 360° cylindrical wall portions of the container and closure which contain threads, and the wall portions are shown in a flat orientation; FIG. 2 is an enlarged, fragmentary, side elevational view of the container and closure prior to assembly; FIG. 3 is a fragmentary, top plan view of the container neck taken generally along plane 3--3 in FIG. 2; FIGS. 4, 6, and 8 are enlarged, fragmentary, partial cross-sectional views showing the operational sequence of screwing the closure onto the container; FIGS. 5, 7, and 9 are fragmentary, cross-sectional views taken generally along the planes 5--5, 7--7, and 9--9 in FIGS. 4, 6, and 8, respectively; FIG. 10 is a fragmentary, cross-sectional view of the closure and container of FIGS. 1-9 showing the closure fully assembled on the container; FIG. 11 is a view similar to FIG. 10, but FIG. 11 shows a second embodiment; and FIG. 12 is a greatly enlarged, fragmentary view of the area within the broken line circle designated "FIG. 12" in FIG. 11. DESCRIPTION OF THE PREFERRED EMBODIMENTS While this invention is susceptible of embodiment in many different forms, this specification and the accompanying drawings disclose only some specific forms as examples of the invention. The invention is not intended to be limited to the embodiments so described, however. The scope of the invention is pointed out in the appended claims. For ease of description, the components of this invention are described in the normal (upright) operating position, and terms such as upper, lower, horizontal, etc., are used with reference to this position. It will be understood, however, that the components of this invention may be manufactured, stored, transported, used, and sold in an orientation other than the position described. The closure of this invention may be applied to a container of this invention with a conventional, high speed capping machine, the details of which, although not fully illustrated or described, will be apparent to those having skill in the art and an understanding of the necessary functions of such machines. The detailed descriptions of such machines are not necessary to an understanding of the invention and are not herein presented because such machines form no part of the present invention. The present invention provides a package in the form of a container enclosure which incorporates a thread system for accommodating mounting of the closure on the container in a way that prevents easy removal of the closure. FIG. 1 illustrates the container designated generally by the reference number 30 and a closure designated generally by the reference number 32. The closure 32 is adapted to be threadingly mounted on the container 30. The container 30 typically includes a body portion or a receptacle portion (not visible in the figures) which may have any suitable, special or conventional configuration and from which a neck 36 extends (as shown in FIG. 1). The neck 36 defines an opening through which the container contents can be dispensed. As best illustrated in FIG. 1, the closure 32 includes a housing, base, or body 40 for securement to the container neck 36. The closure body 40 includes a peripheral wall in the form of a generally cylindrical skirt 44. Typically, the upper end of the closure skirt 44 is closed with, or merges with, a horizontal, transverse deck structure (not illustrated) which defines a suitable dispensing aperture or orifice. Typically, a lid (not illustrated) is mounted to the closure base 40 for movement between a closed position on the deck for occluding the orifice and an open position away from the deck to permit the container contents to be dispensed through the orifice. The container neck 36 has a generally cylindrical configuration. The exterior surface of the neck 36 defines a first thread 51, and the closure skirt 44 defines, on its interior surface, a second thread 52. In the preferred embodiment illustrated, the container neck 36 also defines a third thread 53, and the closure skirt defines a fourth thread 54. Although the container neck threads 51 and 53 are illustrated as exterior, male threads, and although the closure skirt threads 52 and 54 are illustrated as interior, female threads, it will be appreciated that the threads on the container neck could be female threads located on the inside of the container neck while the threads on the closure skirt could be male threads located on the outside of the closure skirt. The container threads 51 and 53 each extends partially around the container neck 36 and together define a double lead thread system. Similarly, the closure skirt threads 52 and 54 each extends partially around the inside circumference of the skirt and together define a double lead thread system. Each thread 51, 52, 53, and 54 defines a leading end A, a helical portion B, and a trailing end C (FIG. 1A). The leading end A of the container threads 51 and 53 is tapered on the side facing inwardly away from the end of the container. Similarly, the leading end A of the closure threads 52 and 54 is tapered on the side facing inwardly away from the open end of the closure skirt 44. The side of each leading end A of the container threads 51 and 53 which faces toward the end of the container defines a helical surface extending partly around the container neck 36 and becomes part of the thread helical portion B. In a preferred embodiment, the helix angle is 3 degrees and 40 minutes. Similarly, the leading ends A of the closure threads 52 and 54 have a surface facing outwardly toward the open end of the closure, and that surface defines a generally helical angle which extends partly around the closure skirt and becomes part of the helical portion B of each thread. In the preferred embodiment, the helical portion B of the closure threads 52 and 54 has a helix angle of 3 degrees and 40 minutes. As can be seen in FIG. 1A, the trailing end C of the container third thread 53 has a 0° helix angle and converges with the first thread helical portion B to define a space which is less than the width of the closure second thread 52. The trailing end C of the container third thread 53 may be alternatively characterized as functionally defining a "projection" on the container neck adjacent the first thread 51, and this projection defines, in cooperation with the first thread 51, the space which is less than the width of the closure second thread 52. The trailing end C of the container first thread 51 similarly has a 0° helix angle and converges toward the helical portion B of the third thread 53. The first thread trailing end C may also be defined as a projection adjacent the first thread helical portion B. Similarly, on the closure skirt, the trailing end C of the second thread 52 has a 0° helix angle and converges toward the helical portion of the fourth thread 54. Likewise, the trailing end C of the fourth thread 54 on the closure has a 0° helix angle and converges toward the helical portion B of the closure second thread 52. Each trailing end C of a thread may be regarded as a projection which, together with the helical portion B of the adjacent thread defines a reduced space which is less than the thread width. It will be appreciated that the trailing end C of each thread does not necessarily have to be flat or have a 0° helix angle. However, the trailing end C must have an angle less than the helix angle of the helical portion B so as to converge toward the helical portion of the adjacent thread and define a reduced width space. It will also be appreciated that in an alternative embodiment (not illustrated), the trailing ends C can be omitted and replaced with other suitable projections to define, in cooperation with the adjacent thread, a reduced space. FIG. 2 shows the closure 32 generally coaxially aligned with the container neck 36 just prior to moving the closure onto the container neck 36 and effecting a threaded engagement. FIGS. 4-8 sequentially illustrate the threading of the closure 32 onto the container neck 36. In FIG. 4, the closure second thread 52 has been threaded between the container threads 51 and 53. The leading end A of the closure second thread 52 has begun to move into the decreasing space defined by the 0° helical angle trailing end C of the container thread 53 and the helical portion B of the container thread 51. As shown in FIG. 5, the container thread 53 starts to deform somewhat. Depending upon the thread profile design and upon the materials employed, the closure thread 52 may also deform somewhat. Also, the closure skirt 44 may deflect slightly radially outwardly. In addition, there may be some upward deformation of the container thread 51. Preferably, the deformation is elastic and temporary. At the point illustrated in FIGS. 4 and 5, the torque resistance to further threading engagement is starting to increase. Sufficient increased torque must be applied to continue the threading process and to further deform the threads. As the closure is rotated further in the screwing-on, or engaging direction, the lower surface of the 0° helix angle trailing end C of the closure second thread 52 begins to engage the upper surface of the 0° helix angle trailing end C of the container thread 53. At the same time, the upper surface of the helical portion B of the closure thread 54 engages the lower side of the 0° helix angle trailing end C of the third thread 53 of the container. The rotational movement (in the screwing on direction) is resisted by the interference between these thread parts. When the screwing on torque is increased sufficiently, the closure threads 52 and 54 move suddenly downwardly with somewhat of a snap action as the system undergoes sufficient deformation to accommodate the axial advancement of the closure in the screwing on direction. At that point, the closure threads 52 and 54 become positioned fully below the container threads 51 and 53 as illustrated in FIGS. 8 and 9. Further, as can be seen in FIG. 8, the 0° helix angle trailing portion C of the closure thread 52 is adjacent the bottom of the container thread 53. With reference to FIGS. 4-9, it will be appreciated that the action of only one-half of the thread system is visible as the closure thread 52 snaps over and below the container thread 53. However, it will be understood that, at the same time, 180° around the container, the closure thread 54 is being snapped over and below the container thread 51. Thus, the 0° helix angle trailing end C of the closure thread 54 becomes located below, and adjacent, the bottom of the container threads. Because the trailing ends C of the closure threads 52 and 54 have a 0° helix angle, and because the trailing ends C of the container threads 51 and 53 have a 0° helix angle, it is not possible to re-engage the threads by rotating the closure in an unscrewing direction. Consequently, once the closure 32 has been driven to the fully assembled position illustrated in FIGS. 8 and 9, the closure 32 merely rotates freely in the unscrewing direction (as well as in the screwing on direction). In a presently contemplated, preferred embodiment, the thread pitch (i.e., the distance between the helical portions of two adjacent threads) is 0.125 inch. The thread system has a 0.25 inch lead (i.e., the theoretical distance that the closure would move axially if it was rotated one 360° revolution on the thread system). In the preferred embodiment illustrated in FIGS. 1-9, a double lead thread system is employed. Thus, the container includes two threads, threads 51 and 53, and the closure includes two threads, threads 52 and 54. It will be appreciated, however, that other thread combinations are possible. For example, a single thread could be provided on the closure, and a single mating thread could be provided on the container. However, the use of a double lead thread system permits the threading forces to be balanced 180° apart, and this provides more effective control during the threading process. With the double lead thread system of the preferred embodiment, the combined length of the leading end A and helical portion B of each thread is 205°, and the trailing end C (along a 0° angle) has an arc length of 90°. With this configuration, the closure need be rotated only about 295° in order to drive the closure threads completely past the container threads to the fully mounted position illustrated in FIG. 8. In the illustrated preferred embodiment having a double lead thread and wherein each thread has a 0° angle trailing end C, the minimum length of the trailing end C is determined by the formula 360°/[2 × (number of leads)]. The novel thread system of the present invention permits application of the closure by a high-speed capping machine with torques which are relatively low compared to other closure/container attachment structures, such as bayonet, bead type configurations or ratchet type configurations. Nevertheless, despite the relatively low application torque required for the present invention, the closure and container remain attached in a manner that prevents the typical user from manually removing the closure from the container. FIG. 10 illustrates the closure base 40 mounted on the neck 36 of the container 30 in a fully assembled condition wherein the closure threads are disengaged from, and positioned below, the container threads. In the embodiment illustrated in FIG. 10, the container includes a shoulder 62 at the base of the neck 36, and the top of the shoulder 62 has a frustoconical surface 64 merging with the neck 36. The threads on the closure base 40 are located inwardly from the bottom, open end of the closure base 40 so as to accommodate the shoulder 62 and frustoconical surface 64. As illustrated in FIG. 10, there is a small, annular space D between the exterior surface of the shoulder 62 and the interior surface of the closure base 40. This space is sufficient to accommodate normal manufacturing tolerances, but is small enough to prevent significant lateral movement of the closure base 40 on the bottle neck 36. This inhibits efforts to cock the mounted closure and re-engage the threads in an attempt to unscrew the closure. An alternate embodiment of the package of the present invention is illustrated in FIGS. 11 and 12. FIGS. 11 and 12 illustrate a closure base 40' fully assembled on the neck 36' of a container 30' with the threads of the closure base 40' located below the threads of the container neck 36'. A double lead thread system is shown in the embodiment illustrated in FIGS. 11 and 12, and this double lead thread system is identical with that described above with reference to the embodiment illustrated in FIGS. 1-10. The alternate embodiment in FIGS. 11 and 12 includes a special centering bead 71 located near the base of the neck 36'. The bead 71 is designed to reduce the capability of the closure base 40' to be angled or cocked on the container neck 36'. Such cocking of the closure base 40' might otherwise make it somewhat easier to attempt to force the threads into engagement when a simultaneous unscrewing torque is applied. The centering bead 71 resides below the leading ends of the closure threads, and the bead 71 prevents the closure threads from being tilted or moved radially inwardly a significant amount. Further, the closure base 40' also preferably includes a shallow bead 81 around the bottom, interior periphery of the closure skirt. The bead 81 is located vertically below the container centering bead 71. As illustrated in FIG. 12, there is a lateral, or radial, clearance x between the container neck 36' and the closure bead 81. There is also a vertical clearance y between the top of the closure bead 81 and the container centering bead 71. The clearances x and y are sufficient to accommodate manufacturing tolerances, but are small enough to prevent significant lateral or vertical movement. This prevents any significant tilting or cocking of the closure base 40' on the container neck 36'. This minimizes the likelihood that the threads can be forced into engagement in an attempt to unscrew the closure. It will be appreciated that the closure bead 81 must be forced or snapped over the container neck centering bead 71 by the axial driving force imparted to the closure base 40' during the application of the closure to the container neck. Removal of the closure would initially require a substantial amount of vertical force which is difficult to provide manually with this embodiment because the closure threads are not readily engageable with the container threads. The container and closure assembly of the present invention may be molded from suitable thermoplastic materials, such as polypropylene and the like. The invention can be embodied in closures and containers produced with conventional manufacturing operations which do not require excessively high or close tolerances. The closure and container components of the present invention accommodate assembly with conventional capping machines and provide a package that inhibits or resists closure removal. It will be readily apparent from the foregoing detailed description of the invention and from the illustrations thereof that numerous variations and modifications may be effected without departing from the true spirit and scope of the novel concepts or principles of this invention.
A removal resistant closure and container assembly is provided. The container defines an opening. The closure is applied to the container to occlude the opening. A first thread is defined by the container and extends at least partially around the opening from a leading end to a trailing end. A second thread is defined by the closure and extends at least partially around the closure form a leading end to a trailing end. A projection is defined adjacent one of the first and second threads. The projection and the one thread define a space between them which is less than the width of the other of the threads. Either the projection or the other thread, or both, are resilient to accommodate deformation during relative rotational movement of the container and closure. When the closure and container are screwed together, the threads are relatively axially displaced from a threadingly engaged condition to a disengaged condition which resists re-engagement.
1
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY The present invention is related to that disclosed in U.S. Provisional Patent Application Ser. No. 60/574,507, filed May 26, 2004, entitled “Vector Table Indirection for Dynamic Forwarding Table Maintenance”. U.S. Provisional Patent Application Ser. No. 60/574,507 is assigned to the assignee of the present application. The subject matter disclosed in U.S. Provisional Patent Application Ser. No. 60/574,507 is hereby incorporated by reference into the present disclosure as if fully set forth herein. The present invention hereby claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 60/574,507. TECHNICAL FIELD OF THE INVENTION The present invention is generally directed to distributed architecture routers and, in particular, to a mechanism for building forwarding tables and supporting high-speed forwarding table lookups in a massively parallel router. BACKGROUND OF THE INVENTION There has been explosive growth in Internet traffic due to the increased number of Internet users, various service demands from those users, the implementation of new services, such as voice-over-IP (VoIP) or streaming applications, and the development of mobile Internet. Conventional routers, which act as relaying nodes connected to sub-networks or other routers, have accomplished their roles well, in situations in which the time required to process packets, determine their destinations, and forward the packets to the destinations is usually smaller than the transmission time on network paths. More recently, however, the packet transmission capabilities of high-bandwidth network paths and the increases in Internet traffic have combined to outpace the processing capacities of conventional routers. This has led to the development of massively parallel, distributed architecture routers. A distributed architecture router typically comprises a large number of routing nodes that are coupled to each other via a plurality of switch fabric modules and an optional crossbar switch. Each routing node has its own routing (or forwarding) table for forwarding data packets via other routing nodes to a destination address. Traditionally, a single processor is used to forward all packets in a router or switch. Even in routers with multiple forwarding table lookup threads, these threads are under control of a single processor and use a single forwarding table. This is true even in routers that use multiple routing nodes, since a single forwarding table and control processor are used in each node. In order to achieve higher throughput speeds, some routers may use two forwarding tables. One forwarding table is used to perform searches while the second table is updated with new routes. After a defined time period, the router switches from one table to the other. However, using a single forwarding processor creates problems in building and switching to new forwarding tables without impeding traffic flow. Some conventional systems simply drop packets during table changes. Two methods may be used to avoid dropping packets. In one method, the router buffers data packets and forwards them after the switch. The other method uses two tables, where one table is written while the other table is read for forwarding lookups. The workload on the control plane processor in building and writing the forwarding tables is significant. However, it is not possible to meet the 10 Gigabit per second (Gbps) forwarding speeds of newer networks using traditional router architectures. This problem is aggravated by the longer searches needed to support the larger address space of IPv6. Memory bandwidth and processing speed limitations prevent support of high data rates and deep trie tree searches. Dropping packets is unacceptable, especially with high data rates and large tables, where vast quantities of packets would be dropped during the switch. Buffering data packets is impractical due to the extremely large quantities of fast memory that would be required by the high data rate. Even if two tables are used, the traditional method of building and/or writing the tables for each processor puts a heavy load on the control plane processor, due to the complexity of the distribution of the forwarding process among network processors, microengines, and threads. The Applicants disclosed an apparatus and a related method for maintaining high-speed lookup tables in U.S. patent application Ser. No. 10/860,691, entitled “Apparatus and Method for Maintaining High-Speed Forwarding Tables in a Massively Parallel Router”, and filed on Jun. 3, 2004. The subject matter disclosed in U.S. patent application Ser. No. 10/860,691 is hereby incorporated by reference into the present disclosure as if fully set forth herein. The router disclosed in U.S. patent application Ser. No. 10/860,691 implemented a plurality of routing nodes, wherein each routing node used an inbound network processor to forward received data packets from external interfaces to a switch fabric and an outbound network processor to forward received data packets from the switch fabric to the external interface. The inbound and outbound network processors in U.S. patent application Ser. No. 10/860,691 used a shared search table or forwarding table to forward data packets. The shared search table was implemented in a field programmable gate array (FPGA) complex and used a vector table to index into a trie tree search table. The shared search table was split into an upper memory bank and a lower memory bank. The microengines of the inbound and outbound network processors used one memory bank to perform lookup operations while a control plane processor of the inbound network processor updated the other memory bank with route information. The microengines would then be periodically switched over to the updated memory bank using a polling table swap mechanism. One disadvantages of the polling table swap mechanism discussed in U.S. patent application Ser. No. 10/860,691 is that the base address of the vector tables must be at a fixed memory location. Another disadvantage is that the reader thread in each network processor must maintain state information on the FPGA state register. Another disadvantage is that both the inbound and outbound network processors must contend for access to the FPGA state register. Therefore, there is a need in the art for an improved high-speed router that is capable of switching between split halves of a search table without using the polling table method described above. In particular, there is a need in the art for a high-speed router in which the vector tables used to index into a trie tree search table are not required to be a fixed location. SUMMARY OF THE INVENTION The present invention provides a mechanism for handling forwarding table swaps that does not require fixing the locations of the vector tables in memory. The present invention may be used with the dynamic forwarding table maintenance apparatus and method disclosed in U.S. patent application Ser. No. 10/860,691, filed on Jun. 3, 2004. The present invention provides an alternative to the polling table swap mechanism disclosed in U.S. patent application Ser. No. 10/860,691. The present invention provides an address passing table swap mechanism that passes the address of the new vector table to the reader thread in each network processor, thereby eliminating the need to monitor the FPGA state register. The present invention also allows the vector table to be placed anywhere in memory and to be moved between updates. Since the FPGA is no longer monitored, the need to keep state information and the monitoring contention are eliminated. Accordingly, to address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide a router for interconnecting external devices coupled to the router. According to an advantageous embodiment of the present invention, the router comprises: 1) a switch fabric; and 2) R routing nodes coupled to the switch fabric, wherein each of the R routing nodes is capable of exchanging data packets with the external devices via network interface ports and with other ones of the R routing nodes via the switch fabric. A first of the R routing nodes comprises: i) an inbound network processor capable of receiving incoming data packets from a network interface port; ii) an outbound network processor capable of transmitting data packets to the network interface port; and iii) a shared memory accessible by the inbound and outbound network processors for storing a current trie tree search table and a current vector table used to index into the current trie tree search table. A control plane processor associated with the first routing node generates an updated vector table to replace the current vector table and notifies the inbound and outbound network processors that the updated vector table is available. According to one embodiment of the present invention, the control plane processor notifies the inbound and outbound network processors that the updated vector table is available by sending an updated vector table address associated with the updated vector table to the inbound and outbound network processors. According to another embodiment of the present invention, a first microengine in the inbound network processor determines that the updated vector table address is different than a current vector table address associated with the current vector table and, in response to the determination, uses the updated vector table identified by the updated vector table address to index into an updated trie tree search table. According to still another embodiment of the present invention, the first microengine executes a reader thread that determines that the updated vector table address is different than the current vector table address and, in response to the determination, causes a plurality of forwarding threads associated with the inbound network processor to use the updated vector table to index into the updated trie tree search table. According to yet another embodiment of the present invention, a second microengine in the inbound network processor determines that the plurality of forwarding threads are using the updated vector table to index into the updated trie tree search table and, in response to the determination, notifies the control plane processor that the plurality of microengines are using the updated vector table and the updated trie tree search table to forward data packets. Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: FIG. 1 illustrates an exemplary distributed architecture router, which performs forwarding table processing according to the principles of the present invention; FIG. 2 illustrates selected portions of the exemplary router according to one embodiment of the present invention; FIG. 3 illustrates the inbound and outbound network processors according to one embodiment of the present invention; FIG. 4 illustrates selected portions of the forwarding tables architecture in greater detail according to an exemplary embodiment of the present invention; FIG. 5 illustrates the operation of the forwarding table architecture of a route processing module according to an exemplary embodiment of the present invention; and FIG. 6 is a flow diagram illustrating an address passing table swap technique according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 through 6 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged packet switch or router. FIG. 1 illustrates exemplary distributed architecture router 100 , which performs forwarding table processing using an address passing table swap technique according to the principles of the present invention. Router 100 supports Layer 2 switching and Layer 3 switching and routing. Thus, router 100 functions as both a switch and a router. However, for simplicity, router 100 is referred to herein simply as a router. The switch operations are implied. According to the exemplary embodiment, router 100 comprises N rack-mounted shelves, including exemplary shelves 110 , 120 and 130 , which are coupled via crossbar switch 150 . In an advantageous embodiment, crossbar switch 150 is a 10 Gigabit Ethernet (10 GbE) crossbar operating at 10 gigabits per second (Gbps) per port. Each of exemplary shelves 110 , 120 and 130 may comprise route processing modules (RPMs) or Layer 2 (L2) modules, or a combination of route processing modules and L2 modules. Route processing modules forward data packets using primarily Layer 3 information (e.g., Internet protocol (IP) addresses). L2 modules forward data packets using primarily Layer 2 information (e.g., medium access control (MAC) addresses). For example, the L2 modules may operate on Ethernet frames and provide Ethernet bridging, including VLAN support. The L2 modules provide a limited amount of Layer 3 forwarding capability with support for small forwarding tables of, for example, 4096 routes. In the exemplary embodiment shown in FIG. 1 , only shelf 130 is shown to contain both route processing (L3) modules and L2 modules. However, this is only for the purpose of simplicity in illustrating router 100 . Generally, it should be understood that many, if not all, of the N shelves in router 100 may comprise both RPMs and L2 modules. Exemplary shelf 110 comprises a pair of redundant switch modules, namely primary switch module (SWM) 114 and secondary switch module (SWM) 116 , a plurality of route processing modules 112 , including exemplary route processing module (RPM) 112 a, RPM 112 b, and RPM 112 c, and a plurality of physical media device (PMD) modules 111 , including exemplary PMD modules 111 a, 111 b, 111 c, 111 d, 111 e, and 111 f. Each PMD module 111 transmits and receives data packets via a plurality of data lines connected to each PMD module 111 . Similarly, shelf 120 comprises a pair of redundant switch modules, namely primary SWM 124 and secondary SWM 126 , a plurality of route processing modules 122 , including RPM 122 a, RPM 122 b, and RPM 122 c, and a plurality of physical media device (PMD) modules 121 , including PMD modules 121 a - 121 f. Each PMD module 121 transmits and receives data packets via a plurality of data lines connected to each PMD module 121 . Additionally, shelf 130 comprises redundant switch modules, namely primary SWM 134 and secondary SWM 136 , route processing module 132 a, a plurality of physical media device (PMD) modules 131 , including PMD modules 131 a and 131 b, and a plurality of Layer 2 (L2) modules 139 , including L2 module 139 a and L2 module 139 b. Each PMD module 131 transmits and receives data packets via a plurality of data lines connected to each PMD module 131 . Each L2 module 139 transmits and receives data packets via a plurality of data lines connected to each L2 module 139 . Router 100 provides scalability and high-performance using up to M independent routing nodes (RN). A routing node comprises, for example, a route processing module (RPM) and at least one physical medium device (PMD) module. A routing node may also comprise an L2 module (L2M). Each route processing module or L2 module buffers incoming Ethernet frames, Internet protocol (IP) packets and MPLS frames from subnets or adjacent routers. Additionally, each RPM or L2M classifies requested services, looks up destination addresses from frame headers or data fields, and forwards frames to the outbound RPM or L2M. Moreover, each RPM (or L2M) also maintains an internal routing table determined from routing protocol messages, learned routes and provisioned static routes and computes the optimal data paths from the routing table. Each RPM processes an incoming frame from one of its PMD modules. According to an advantageous embodiment, each PMD module encapsulates an incoming frame (or cell) from an IP network (or ATM switch) for processing in a route processing module and performs framing and bus conversion functions. Incoming data packets may be forwarded within router 100 in a number of different ways, depending on whether the source and destination ports are associated with the same or different PMD modules, the same or different route processing modules, and the same or different switch modules. Since each RPM or L2M is coupled to two redundant switch modules, the redundant switch modules are regarded as the same switch module. Thus, the term “different switch modules” refers to distinct switch modules located in different ones of shelves 110 , 120 and 130 . In a first type of data flow, an incoming data packet may be received on a source port on PMD module 121 f and be directed to a destination port on PMD module 131 a. In this first case, the source and destination ports are associated with different route processing modules (i.e., RPM 122 c and RPM 132 a ) and different switch modules (i.e., SWM 126 and SWM 134 ). The data packet must be forwarded from PMD module 121 f all the way through crossbar switch 150 in order to reach the destination port on PMD module 131 a. In a second type of data flow, an incoming data packet may be received on a source port on PMD module 121 a and be directed to a destination port on PMD module 121 c. In this second case, the source and destination ports are associated with different route processing modules (i.e., RPM 122 a and RPM 122 b ), but the same switch module (i.e., SWM 124 ). The data packet does not need to be forwarded to crossbar switch 150 , but still must pass through SWM 124 . In a third type of data flow, an incoming data packet may be received on a source port on PMD module 111 c and be directed to a destination port on PMD module 111 d. In this third case, the source and destination ports are associated with different PMD modules, but the same route processing module (i.e., RPM 112 b ). The data packet must be forwarded to RPM 112 b, but does not need to be forwarded to crossbar switch 150 or to switch modules 114 and 116 . Finally, in a fourth type of data flow, an incoming data packet may be received on a source port on PMD module 111 a and be directed to a destination port on PMD module 111 a. In this fourth case, the source and destination ports are associated with the same PMD module and the same route-processing module (i.e., RPM 112 a ). The data packet still must be forwarded to RPM 112 a, but does not need to be forwarded to crossbar switch 150 or to switch modules 114 and 116 . FIG. 2 illustrates selected portions of exemplary router 100 in greater detail according to one embodiment of the present invention. FIG. 2 simplifies the representation of some of the elements in FIG. 1 . Router 100 comprises PMD modules 210 and 250 , route processing modules 220 and 240 , and switch fabric 230 . PMD modules 210 and 250 are intended to represent any of PMD modules 111 , 121 , and 131 shown in FIG. 1 . Route processing modules 220 and 240 are intended to represent any of RPM 112 , RPM 122 , and RPM 132 shown in FIG. 1 . Switch fabric 230 is intended to represent crossbar switch 150 and the switch modules in shelves 110 , 120 and 130 in FIG. 1 . PMD module 210 comprises physical (PHY) layer circuitry 211 , which transmits and receives data packets via the external ports of router 100 . PMD module 250 comprises physical (PHY) layer circuitry 251 , which transmits and receives data packets via the external ports of router 100 . RPM 220 comprises inbound network processor (NP) 221 , outbound network processor (NP) 223 , and medium access controller (MAC) layer circuitry 225 . RPM 240 comprises inbound network processor (NP) 241 , outbound network processor (NP) 243 , and medium access controller (MAC) layer circuitry 245 . Each network processor comprises a plurality of microengines capable of executing threads (i.e., code) that forward data packets in router 100 . Inbound NP 221 comprises N microengines (μEng.) 222 and outbound NP 223 comprises N microengines (μEng.) 224 . Similarly, inbound NP 241 comprises N microengines (μEng.) 242 and outbound NP 243 comprises N microengines (μEng.) 244 . Two network processors are used in each route-processing module to achieve high-speed (i.e., 10 Gbps) bi-directional operations. Inbound network processors (e.g., NP 221 , NP 241 ) operate on inbound data (i.e., data packets received from the network interfaces and destined for switch fabric 230 ). Outbound network processors (e.g., NP 223 , NP 243 ) operate on outbound data (i.e., data packets received from switch fabric 230 and destined for network interfaces). According to an exemplary embodiment of the present invention, each network processor comprises N=16 microengines that perform data plane operations, such as data packet forwarding. Each RPM also comprises a control plane processor (not shown) that performs control plane operations, such as building forwarding (or look-up) tables. According to the exemplary embodiment, each microengine supports eight threads. At least one microengine is dedicated to reading inbound packets and at least one microengine is dedicated to writing outbound packets. The remaining microengines are used for forwarding table lookup operations. In order to meet the throughput requirements for line rate forwarding at data rates up to 10 Gbps, it is necessary to split the data plane processing workload among multiple processors, microengines, and threads. The first partitioning splits the workload between two network processors—one operating on inbound data packets from the network interfaces to the switch and the other operating on outbound data packets from the switch to the network interfaces. Each of these processors uses identical copies of the forwarding table. According to an exemplary embodiment of the present invention, the control and management plane functions (or operations) of router 100 may be distributed between inbound (IB) network processor 221 and outbound network processor 223 . The architecture of router 100 allows distribution of the control and management plane functionality among many processors. This provides scalability of the control plane in order to handle higher control traffic loads than traditional routers having only a single control plane processor. Also, distribution of the control and management plane operations permits the use of multiple low-cost processors instead of a single expensive processor. For simplicity in terminology, control plane functions (or operations) and management plane functions (or operations) may hereafter be collectively referred to as control plane functions. FIG. 3 illustrates inbound network processor 221 and outbound network processor 223 in greater detail according to an exemplary embodiment of the present invention. Inbound (IB) network processor 221 comprises control plane processor 310 and microengine(s) 222 . Outbound (OB) network processor 223 comprises control plane processor 320 and microengine(s) 224 . Inbound network processor 221 and outbound network processor 223 are coupled to shared memory 350 , which stores forwarding table information, including forwarding vectors and trie tree search tables. Inbound network processor 221 is coupled to local memory 330 , which contains packet descriptors 335 and packet memory 336 . Outbound network processor 223 is coupled to local memory 340 , which contains packet descriptors 345 and packet memory 346 . Control and management messages may flow between the control and data planes via interfaces between the control plane processors and data plane processors. For example, control plane processor 310 may send control and management messages to the microengines 222 and control plane processor 320 may send control and management messages to the microengines 224 . The microengines can deliver these packets to the local network interfaces or to other RPMs for local consumption or transmission on its network interfaces. Also, the microengines may detect and send control and management messages to their associated control plane processor for processing. For example, microengines 222 may send control and management plane messages to control plane processor 310 and microengines 224 may send control and management messages to control plane processor 320 . Inbound network processor 221 operates under the control of control software (not shown) stored in memory 330 . Similarly, outbound network processor 223 operates under the control of control software (not shown) stored in memory 340 . According to an exemplary embodiment of the present invention, the control software in memories 330 and 340 may be identical software loads. Network processors 221 and 223 in router 100 share routing information in the form of aggregated routes stored in shared memory 350 . Management and routing functions of router 100 are implemented in inbound network processor 221 and outbound network processor 223 in each RPM of router 100 . Network processors 221 and 223 are interconnected through 10 Gbps optical links to exemplary switch module (SWM) 360 and exemplary switch module (SWM) 370 . SWM 360 comprises switch processor 361 and switch controller 362 . SWM 370 comprises switch processor 371 and switch controller 372 . Multiple switch modules may be interconnected through 10 Gbps links via Rack Extension Modules (REXMs) (not shown). In order to meet the bi-directional 10 Gbps forwarding throughput of the RPMs, two network processors—one inbound and one outbound—are used in each RPM. Inbound network processor 221 handles inbound (IB) packets traveling from the external network interfaces to switch fabric 230 . Outbound network processor 223 handles outbound (OB) packets traveling from switch fabric 230 to the external network interfaces. In an exemplary embodiment of the present invention, control plane processor (CPP) 310 comprises an XScale core processor (XCP) and microengines 222 comprise sixteen microengines. Similarly, control plane processor (CPP) 320 comprises an XScale core processor (XCP) and microengines 224 comprise sixteen microengines. According to an exemplary embodiment of the present invention, router 100 implements a routing table search circuit as described in U.S. patent application Ser. No. 10/794,506, filed on Mar. 5, 2004, entitled “Apparatus and Method for Forwarding Mixed Data Packet Types in a High-Speed Router.” The disclosure of U.S. patent application Ser. No. 10/794,506 is hereby incorporated by reference in the present application as if fully set forth herein. The routing table search circuit comprises an initial content addressable memory (CAM) stage followed by multiple trie tree search table stages. The CAM stage allows searches to be performed on data packet header information other than regular address bits, such as, for example, class of service (COS) bits, packet type bits (IPv4, IPv6, MPLS), and the like. The use of multiple threads in multiple microengines enables network processors 221 and 223 to modify a data packet during its transit through router 100 . Thus, network processors 221 and 223 may provide network address translation (NAT) functions that are not present in conventional high-speed routers. This, in turn, provides dynamic address assignment to nodes in a network. Since network processors 221 and 223 are able to modify a data packet, network processors 221 and 223 also are able to obscure the data packet identification. Obscuring packet identification allows router 100 to provide complete anonymity relative to the source of an inbound packet. The ability of router 100 to distribute the data packet workload over thirty-two microengines, each capable of executing, for example, eight threads, enables router 100 to perform additional security and classification functions at line rates up to 10 Gbps. FIG. 3 shows the flow of data through route processing module (RPM) 220 . Packets enter RPM 220 through an interface—a network interface (PMD) for inbound network processor (IB NP) 221 and a switch interface for outbound network processor (OB NP) 223 . IB NP 221 and OB NP 223 also may receive packets from control plane processors 310 and 320 . Microengines 222 store these data packets in packet memory 336 in local QDRAM (or RDRAM) memory 330 and write a Packet Descriptor into packet descriptors 335 in local memory 330 . Similarly, microengines 224 store these data packets in packet memory 346 in local QDRAM (or RDRAM) memory 340 and write a Packet Descriptor into packet descriptors 345 in local memory 340 . A CAM search key is built for searching the initial CAM stages of the search tables in memory 350 . The CAM key is built from data packet header information, such as portions of the destination address and class of service (CoS) information and a CAM lookup is done. The result of this lookup gives an index for a Vector Table Entry, which points to the start of a trie tree search table. Other information from the packet header, such as the rest of the destination address and possibly a socket address, are used to traverse the trie tree search table. The search of the CAM stage and trie tree table results in either in a leaf or an invalid entry. Unresolved packets are either dropped or sent to control plane processors 310 and 320 for further processing. A leaf node gives a pointer to an entry in a forwarding table (i.e., a Forwarding Descriptor) in memory 350 . Since shared memory space is limited, these forwarding tables may be located in local memory 330 and 340 . Based on the results of the search, the packet is forwarded to the control plane, to another RPM network processor, to an L2 module, or to an output port (i.e., a switch port for IB NP 221 and a network interface port for OB NP 223 ). The data packet is not copied as it is passed from microengine thread to microengine thread. Only the pointer to the Packet Descriptor must be passed internally. This avoids expensive copies. In the exemplary embodiment of router 100 , a control plane processor (CCP) builds the forwarding tables. In particular, CCP 310 in inbound network processor 221 builds the forwarding tables. Forwarding table lookup operations are done by micro-engines 222 and 224 of IB NP 221 and OB NP 223 , operating in the data plane. In order to meet 10 Gbps throughput requirements, contention between accesses to the forwarding tables by IB NP 221 and OB NP 223 must be avoided. This is accomplished by giving each network processor a dedicated bank of memory (i.e., QDRAM) for forwarding tables. The same forwarding table is written to a shared QDRAM for both IB NP 221 and OB NP 223 . Each network processor reads its own portion of shared QDRAM, thus avoiding read contention between IB NP 221 and OB NP 223 . FIG. 4 illustrates selected portions of the forwarding tables architecture in RPM 112 in greater detail according to an exemplary embodiment of the present invention. Shared memory 350 comprises inbound upper bank 440 , inbound lower bank 445 , outbound upper bank 450 , and outbound lower bank 455 . Local memory 330 comprises local RDRAM 431 and local QDRAM 432 . Local memory 340 comprises local RDRAM 441 and local QDRAM 442 . RPM 112 also comprises content addressable memory (CAM) 425 and memory controller 410 . Memory controller 410 comprises field programmable gate array (FPGA) 420 , which stores state register 421 , inbound transition complete (ITC) indicator 422 , and outbound transition complete (OTC) indicator 423 . Inbound network processor 221 runs the routing protocols, so IB NP 221 is selected to build the forwarding tables. The forwarding tables must be updated periodically, for example, once every 100 milliseconds. Building a forwarding table is a long process and the packet data rate is very high. Thus, it is not practical to stop packet flow while the forwarding tables are being built or updated. Thus, in an advantageous embodiment, router 100 implements two banks of QDRAM for each of network processors 221 and 223 . IB NP 221 uses inbound upper bank 440 and inbound lower bank 445 and OB NP 223 uses outbound upper bank 450 , and outbound lower bank 455 . One QDRAM bank is written while the other QDRAM bank is read. To speed forwarding table construction and to reduce the workload on IB NP 221 , forwarding table writes by IB NP 221 are automatically written to both the inbound and outbound shared QDRAM simultaneously. As described above, multiple microengines and threads are involved in forwarding table lookup operations. A thread can only transition to a new forwarding table between data packets. Since packet processing within IB NP 221 and OB NP 223 is not synchronized and search depth varies from data packet to data packet, not all threads change tables at the same time. This is aggravated by the fact that microengines 222 and 224 , located in different network processors, use the tables. Throughput requirements do not allow threads to halt until all threads have transitioned to a new set of tables. Therefore, there is a transition period where some threads use the old set of tables and others use the new set of tables. During this transition period, both the upper and lower banks of the shared QDRAM of each network processor must be accessible by the microengines for read access. There are four states for the shared QDRAM selected by state register 421 in FPGA 420 : 1) Uninitialized; 2) Transition Period; 3) Upper Forwarding Table Active; and 4) Lower Forwarding Table Active. If state register 421 is in the Initialized state, there are no valid forwarding tables for microengines 222 and 224 to use for forwarding packets. If state register 421 is in the Transition Period state, each network processor has read access to both its upper and lower shared QDRAM banks. Write access is optional, but not necessary since software should not be writing forwarding tables during this time period. If state register 421 is in the Upper Forwarding Table Active state, each network processor has read access to its own upper bank. Control plane processor (CPP) 310 in IB NP 221 has simultaneous write access to both inbound lower bank 445 and outbound lower bank 455 of shared QDRAM memory 350 . These are the only access modes required. Any other access, such as write access by each processor to its own upper bank, is optional. If state register 421 is in the Lower Forwarding Table Active state, each network processor has read access to its own lower bank. Control plane processor (CPP) 310 in IB NP 221 has simultaneous write access to both inbound upper bank 440 and outbound upper bank 450 of shared QDRAM memory 350 . These are the only access modes required. Any other access, such as write access by each processor to its own lower bank, is optional. FPGA 420 initializes the memory state in state register 421 to [00] (i.e., uninitialized) and clears Inbound Transition Complete (ITC) indicator 422 and Outbound Transition Complete (OTC) indicator 423 . This is an indication to microengines 222 and 224 that there are no valid tables for forwarding packets. CPP 310 controls the memory state transitions. In this example, the IB NP 221 writes the upper banks first. CPP 310 begins by selecting inbound upper bank 440 and outbound upper bank 450 for write. To do this, CPP 310 sets the memory state to [01] (i.e., Lower Forwarding Table Active) to begin writing the upper banks. This is a signal to FPGA 420 to give IB NP 221 simultaneous write access to the upper memory banks of shared memory 350 . CPP 310 then builds the forwarding tables in the upper banks. When the forwarding table is complete, CP 310 changes the memory state to [10] (i.e., Upper Forwarding Table Active), allowing CPP 310 to have simultaneous write access to the lower memory banks of shared memory 350 . This is a signal to the hardware to swap write access from upper banks 440 and 450 to lower banks 445 and 455 of memory 350 . Microengines 222 and 224 do not start forwarding packets until the second state change (i.e., until the state is [10]). At this point, microengines 222 and 224 read the forwarding tables in their upper banks, CPP 310 writes tables to the lower banks, and normal forwarding table update processing begins. In normal forwarding table update processing, when IB NP 221 is done writing a bank of tables, IB NP 221 sets the memory state to [11], indicating a transition period and clears both ITC indicator 422 and OTC indicator 423 in FPGA 420 . At this point, FPGA 420 gives microengines 222 and 224 read access to both the upper and lower memory banks. No forwarding table writing takes place during this transition period. The microengine reader function sees the state change and informs each microengine forwarding thread of the table change. Each forwarding thread examines the table change indicator with the start of each new packet, transitions to the new forwarding table when commanded, and updates its transition status when the transition has occurred. Forwarding threads that are not assigned work continually scan the table change indicators in order to track the bank changes and can signal completion of the table change. The microengine write function monitors each forwarding thread and sets its transition complete flag when all of its threads have transitioned. IB NP 221 monitors ITC indictor 422 and OTC indicator 423 . When both are set, the transition is complete. IB NP 221 clears ITC indicator 422 and OTC indicator 423 and requests write access to the other bank through the memory state register. IB NP 221 then starts writing the other bank and the cycle continues with updates approximately every 100 milliseconds. It is noted that threads may see the transition state (11) for multiple packets, while the transition completes in other threads. For this reason, the microengines do not change state each time the microengines see the transition state, but only if the microengines see a transition from a different state at the start of the previous packet to the transition state at the start of the current packet. Construction of the forwarding structure is the responsibility of control plane processor (CPP) 310 . The forwarding structure is composed of fours parts: 1) a CAM Key Set, 2) a Vector Table, 3) Trie Tree Tables, and 4) a set of Forwarding Descriptors, also known as Forwarding Table Entries. IB NP 221 accesses its own shared QDRAM and the shared QDRAM of OB NP 223 to simultaneously write the Vector Table and the Trie Tables for each network processor. Each network processor reads its own shared QDRAM banks for forwarding table lookups, thus avoiding memory contention during packet forwarding. Each shared QDRAM is split into two banks, an upper bank and a lower bank, to allow writing the next set of forwarding tables in one bank while the other bank is being read for forwarding table lookups. The forwarding table entries (also called forwarding descriptors) are kept in the local RDRAM 431 and 441 of each network processor 221 and 223 . CPP 310 is responsible for building these entries, writing the entries into its own RDRAM 431 , and sending requests to CPP 320 to write them into RDRAM 441 . CPP 320 simply writes the forwarding table entries into local RDRAM 441 , as requested. FIG. 5 illustrates the operation of the forwarding table architecture of exemplary route processing module 112 according to an exemplary embodiment of the present invention. Data packets enter RPM 112 through an interface (i.e., a network interface for IB NP 221 and a switch interface for OB NP 223 ). Each one of IB NP 221 and OB NP 223 also receives packets from CPP 310 and CPP 320 , respectively. Microengines 222 and 224 place the data packets into packet memory 336 and packet memory 346 (not shown), located in local inbound (IB) RDRAM 431 and local outbound (OB) RDRAM 441 , respectively. Microengines 222 and 224 also write to packet descriptor 335 and packet descriptor 345 in local IB QDRAM 432 and local OB QDRAM 442 , respectively. CAM key 520 is built from header information, such as portions of the destination address and QoS information, and a lookup operation in CAM 425 is done. The result of this lookup gives a pointer to an entry in vector tables 525 , which points, in turn, to the start of a trie tree in trie tree structure 530 . Other information from the packet header, such as the rest of the destination address, is used to traverse trie tree structure 530 . This search ultimately accesses either a leaf node or an invalid entry. Unresolved packets are either dropped or sent to control plane processor 310 (or 320 ). A leaf node gives a pointer to a forwarding table entry (or forwarding descriptor) in forwarding table 510 . The data packet is forwarded based on the results of the search to the control plane, to the other network processor, or to an output port (i.e., a switch port for IB NP 221 and a network interface port for OB NP 223 ). At processor start time, the initial trie tree structure 530 is constructed from a set of prior known static routes. Since there are no previous processed routes at this point, CAM key 520 is empty, there are no trie trees, and there are no forwarding descriptors. As each route is added, the appropriate CAM key entry is made (e.g., MPLS, IPv4, or IPv6). CAM 425 contains key-result pairs. As new entries are added to CAM 425 , additional result values are consumed. The resultant value from the CAM search is an index value. This index value is the originally assigned value when the pair was added to CAM 425 . The index value for a CAM key will not vary for the life of the entry. The index value is used to subscript into a vector table. The value at the vector table entry is a pointer to the top of the corresponding trie tree. This indirection is required because the tops of the trie trees are not guaranteed to be located at the same memory address from one construction iteration to the next. CPP 310 builds the trie tree for each route. CPP 310 uses the subnet mask to determine the location of the leaf (i.e., to determine the depth of the search). CPP 310 marks the leaf node with a special code or flag and sets the leaf node to point to the forwarding table entry (or descriptor) for the route. The trie trees are stored in shared QDRAM memory 350 . Each one of IB NP 221 and OB NP 223 has copies of the vector tables and the trie trees that are used to search for the forwarding table entry. The end of a trie tree gives a forwarding descriptor. Forwarding descriptors are fixed in memory and do not change, but may be deleted. Forwarding descriptors are stored in RDRAMs that are local to each network processor. Since IB NP 221 is responsible for constructing the lookup tables, IB NP 221 must request OB NP 223 to put forwarding descriptors into the required locations in RDRAM 441 . Trie trees are constructed by following the address path stored as part of the forwarding descriptor. Once vector table 525 and trie tree structure 530 are constructed, IB NP 221 informs microengines 222 and 224 that a new vector table is available by setting state register 421 to 11. A reader thread on a microengine discovers this change. The reader thread in each network processor passes the change request on to each of the forwarding threads. The forwarding threads monitor for a table change at the beginning of each data packet, switch to the new table for the lookup of that packet if a table change is indicated, and inform the writer process that the forwarding threads have transitioned to the new table. A thread on the writer microengine of each network processor determines when all the forwarding threads have switched to the new routing set, at which time the writer thread informs the control plane of the completion of the switch by writing a transition complete indicator (i.e., ITC indicator 422 for IB NP 221 and OTC indicator 423 for OB NP 223 ). One approach to signaling forwarding table swaps and handling vector table changes is the polling table swap technique described above, wherein microengine reader threads in IB NP 221 and OB NP 223 poll state register 421 in the FPGA complex looking for the transition state. With the polling method, when the forwarding table update application wants to swap in new tables, the forwarding table update application calls the Linux driver, which clears ITC indicator 422 and OTC indicator 423 and sets the state to [11] in the FPGA to signal a transition. The reader threads in both IB NP 221 and OB NP 223 monitor state register 421 . When the transition state [11] is seen, the reader thread in each network processor signals each of its forwarding threads to transition to the alternate tables in the other memory bank. Each forwarding thread monitors for table swap signals at the beginning of each data packet. If a table swap is signaled, each forwarding thread sends a signal to its writer thread indicating that a transition has occurred and begins forwarding the next packet using the new tables. When the writer thread detects that all its forwarding threads have transitioned to the new tables, the writer thread sets its transition complete indicator. The inbound writer thread sets ITC indicator 422 and the outbound writer thread sets OTC indicator 423 . When the Linux driver finds both ITC and OTC indicators set, the Linux driver informs the forwarding table update application that the transition is complete. The application then selects state [10] or [01] to write the next set of tables. The reader thread only signals the transition, when the reader thread sees a change from a state other than [11] to the state [11]. Thus, keeping the state at [11] does not cause continual table swaps. The signaling between the reader and writer threads and the forwarding threads takes the form of a flag for each forwarding thread. The reader thread sets each forwarding thread flag to signal a transition. The forwarding thread clears its flag to signal it has completed the transition. This above method assumes that the base address of the vector table is in a fixed location in both the upper and lower banks of memory. This places a constraint on the memory maps, namely that the location of the vector tables cannot be changed. For example, increasing the sizes of these memory spaces could result in the need to change the starting addresses of the vector tables, which would force an update to the microengine code. Also, the above-described method forces the reader thread to keep track of current and previous states in FPGA state register 421 to prevent continual table swapping. Both IB NP 221 and OB NP 223 reader threads are monitoring the same state register, leading to possible contention problems. These problems may be overcome by an address passing table swap technique according to the principles of the present invention. The address passing table swap technique does not fix the locations (addresses) of the upper and lower memory bank vector tables. Instead, the address passing table swap technique passes the vector table address to the reader thread in the microengine. This has the advantage of not tying the microengine code to a fixed memory map, relative to the locations of the vector tables. It also frees the reader thread from keeping state information on state register 421 to prevent continual table swapping and eliminates the contention related to having both the inbound and outbound network processor reader threads monitoring state register 421 . FIG. 6 depicts flow diagram 600 , which illustrates an address passing table swap technique according to one embodiment of the present invention. After CPP 310 constructs a vector table and trie tree set, the application program running in CPP 310 causes a Linux driver to notify memory controller 410 , microengines 222 in IB NP 221 , and microengines 224 in OB NP 223 that the new vector table is available (process step 605 ). This is done by setting state register 421 to [11], by clearing ITC indicator 422 and OTC indicator 423 , and by sending the Requested Vector Table (RVT) address to the reader microengine in both IB NP 221 and OB NP 223 . The reader thread on the reader microengine in each one of IB NP 221 and OB NP 223 discovers this change by determining that the received RVT address does not match one of the RVT ij values in the microengine. The reader thread in each one of IB NP 221 and OB NP 223 sets the Requested Vector Table (RVT ij ) address for each of the forwarding threads in each microengine (Forwarding Thread ij ), where i is the microengine number and j is the thread number (process step 610 ). The forwarding threads monitor for a table change at the beginning of each packet by looking for the Requested Vector Table (RVT ij ) address to be different from the Current Vector Table (CVT ij ) address. When a table switch is requested, the forwarding threads switch to the new table for forwarding the next packet and inform the writer process that the forwarding threads have transitioned to the new table by updating the Current Vector Table (CVT ij ) address (process step 615 ). A thread on the writer (WRT) microengine of each one of IB NP 221 and OB NP 223 determines when all the forwarding threads have switched to the new Requested Vector Table (RVT) address, at which time the writer thread informs memory controller 410 (i.e., the FPGA) and control plane processors 310 and 320 of the completion of the switch (process step 620 ). The writer microengine does this by writing its transition complete indicator (i.e., ITC indicator 422 for IB NP 221 and OTC indicator 423 for OB NP 223 ). The Linux driver monitors ITC indicator 422 and OTC indicator 423 . When both are set, the Linux driver informs the forwarding table update application executed by CPP 310 that the transition is complete (process step 625 ). Then CPP 310 can use the state register to select the banks to be written next. Although the present invention has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
A router for interconnecting external devices comprising: 1) a switch fabric; and 2) R routing nodes coupled to the switch fabric. Each of the R routing nodes exchanges data packets with the external devices via network interface ports and with other routing nodes via the switch fabric. A first routing node comprises: i) an inbound network processor for receiving incoming data packets from a network interface port; ii) an outbound network processor for transmitting data packets to the network interface port; and iii) a shared memory accessible by the inbound and outbound network processors for storing a current trie tree search table and a current vector table used to index into the trie tree search table. A control plane processor generates an updated vector table to replace the current vector table and notifies the inbound and outbound network processors that the updated vector table is available.
7
REFERENCE TO RELATED APPLICATION [0001] The present application claims the benefit of the filing date of Dec. 10, 2003 of U.S. Provisional Patent Application No. 60/528,315. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a stent and to a percutaneous balloon system facilitating the placement of the stent in the lumen of a patient. More particularly, the invention pertains to a stent and balloon system, which may constitute an integrated delivery system for dilatation and/or the placement of a stent or of stents, which is especially intended for, but not limited to applications in connection with bifurcated vessels and lesions. Moreover, the invention is also directed to the provision of a novel method of deploying the stent at a particular site through the intermediary of the inventive balloon system. [0004] In essence, the medical technology has at this time been extensively developed with regard to the concepts of developing the delivery and deployment of diverse types of luminal stents and stent positioning devices, such as balloons for inserting and positioning such luminal stents. In particular, in the current medical technology stents are extensively employed in connection with implementing procedures, such as balloon angioplasty, and are effectively employed in the treatment of coronary artery disease. [0005] Furthermore, although the advances in the placement of stents while maintaining the patency or integrity of the body lumen or vessel of a patient in the treatment of coronary obstructions represent a significant breakthrough in interventional cardiology, at present there is no effective treatment available through a dedicated percutaneous treatment system which is able to implement the treating of and obviating the problems which are encountered in the presence of particularly challenging lesion subsets. [0006] Concerning the foregoing aspects, it is essential that a number of challenges must be currently considered in the conceptualizing or designing of a dedicated system adapted for the treatment of bifurcated lesions which occur in the body vessels or lumen of a patient, and which reflect various medical and technological viewpoints in the design and methods of use of such a treatment system, the latter of which may be either deemed a separate stent and balloon design, or the provision thereof as a dedicated or integrated treatment system. [0007] In particular, various important and diverse criteria must be met in providing a dedicated system for the treatment of bifurcated lesions, which are encountered in the body vessels or lumen of a patient. These criteria can essentially be enumerated as follows: 1) A stent and balloon deployment system that is not cumbersome in the use thereof by a physician or surgeon. 2) A system that is compatible with a wide range of guide catheter sizes. 3) A system that is sufficiently flexible to be able to accommodate any size of combinations of main and side branches of a lumen or body vessel of a patient. 4) A system that is sufficiently flexible to be adapted for any angular combinations, which are present between main and side branches of the lumen or body vessels of a patient. 5) A system which is capable of minimizing any danger of encountered wire entanglement or crossing during deployment prior to reaching the site of the branch point. 6) Providing an inventory of stent and balloon systems adapted for large size combinations of lumen side and main branches, which is maintained within reasonable and economical bounds. 7) In the sphere of drug eluting stents, providing a design that would maximize vessel/stent strut contact for optimal drug delivery to the patient. 8) A stent and balloon system design that would not require the deployment of any advanced or technically demanding new implantation techniques, but is compatible with currently available technologies. [0016] 2. Discussion of the Prior Art [0017] Although numerous patents and publications are currently in existence, which are directed to the disclosures of diverse types of luminal stents and delivery systems, including devices such as balloons employed in angioplasty for inserting and locating the luminal stents at specified sites and thereafter fixed in the patient's vessel, for instance, as in a blood vessel or other locales, these are not specifically designed and generally not suited for the treatment of bifurcated vessels and lesions. [0018] Igaki, U.S. Pat. No. 5,762,625, discloses a luminal stent which is adapted to be introduced into a blood vessel, lymph vessel, bile duct, ureter, or esophagus among others for maintaining the shape or patency of the vessel, and wherein a balloon delivery arrangement may be employed for positioning and fixing the stent at a particular site. However, in this patent, there is no capability or concept of employing the stent and balloon delivery system for the treatment of bifurcated vessels and lesions in a manner analogous to that provided by the present invention. [0019] Bosley, Jr., U.S. Pat. No. 5,514,176 discloses a pull apart coil stent which is adapted to be deployed in a body lumen, such as a urethra, ureters, common bile duct, vagina, cervix, fallopian tubes, sinus tract, rectum, bowel, esophagus or in the vascular system of a patient and also describes structure whereby the configuration of the coil may be varied in order to enable the positioning and any required removal thereof. This may be implemented through the intermediary of a suitable balloon catheter, for example, of the type described in the Palmas, U.S. Pat. No. 4,739,762, or the Giantorko, U.S. Pat. Nos. 4,580,568 and 4,907,336. None of these patents are adapted to provide nor do they disclose treatment systems employing the unique stent and balloon delivery arrangements of the invention for the treatment of bifurcated vessels and lesions. [0020] Myler, et al., U.S. Pat. No. 5,474,563, discloses a cardiovascular stent and retrieval apparatus, whereby the stent may be inserted and retrieved through the intermediary of a balloon system, which is deployed in the lumen or body vessel of a patient. As in the previously discussed patents, there is no disclosure of the inventive type of stent and balloon delivery system, which is adapted for the treatment of bifurcated vessels and lesions. [0021] Eury, U.S. Pat. No. 5,443,458, discloses a multilayered biodegradable stent and method of manufacture thereof, and does not concern itself with a novel stent and balloon delivery system employed for the treatment of bifurcated vessels and lesions as is disclosed by the present invention. SUMMARY OF THE INVENTION [0022] Accordingly, pursuant to the invention, there is provided a unique and sophisticated advantageous design for a stent and integrated balloon stent delivery system enabling the conveyance to and deployment of the stent at a particular site in the lumen or body vessel of a patient. In particular, such as is contemplated for the treatment of a bifurcated vessel or lesion, there is provided a structure which incorporates a specialized stent and a side hole or aperture in the center portion of a balloon or by means of an integrated slit-tube embedded on a balloon surface, and/or along the shaft of a balloon catheter, in the form of either a separate structure or as an integrated delivery system for dilatation and/or placement of the stent or plurality of stents, while concurrently maintaining the patency of and access to both branches of the bifurcated vessel branch points. Although, especially directed to the treatment of bifurcated vessels or lesions, the inventive structure is not limited thereto. [0023] Pursuant to the invention, the problems and technological challenges, which are set forth hereinabove and which are encountered in the current state-of-the-art are fully obviated or at the very least, extensively ameliorated, inasmuch as the novel stent and balloon delivery system, and the methodology of use thereof, clearly address all of the design constraints and issues encountered in the technology. [0024] Accordingly, it is an object of the present invention to provide for a novel stent and balloon delivery system which is designed for, but not limited to the treatment of bifurcated vessels and lesions in the body of a patient. [0025] Another object of the present invention is to provide a unique stent and balloon delivery system for the placement of a stent at a site, which is adapted for the treatment of lesions in a body vessel or lumen. [0026] Still another object of the present invention resides in the provision of a unique system of stents and balloon stent delivery systems, which are adapted to effectuate the treatment of bifurcated vessels and lesions, maintaining the patency and access to both branches of a vessel branch point or points. [0027] Another object of the present invention is to provide for a method of utilizing the inventive stent and balloon delivery system in the treatment of obstructive lesions in a body vessel or lumen. [0028] Another object of the invention resides in the provision of a method utilizing the inventive stent and balloon delivery system in the treatment of bifurcated vessels and lesions encountered in the body of a patient. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS [0029] Reference may now be made to the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings; in which: [0030] FIG. 1A and 1B diagrammatically illustrate, respectively, side views in various axially rotated orientations of a stent, which is constructed pursuant to the invention; [0031] FIG. 1C illustrates an enlarged fragmentary view of the center portion of the stent of FIGS. 1A and 1B showing the larger open cell area; [0032] FIG. 2A illustrates diagrammatically, an axial sectional view of a first embodiment of a stent and balloon delivery system for the deployment of the stent at a site in the body of a patient. [0033] FIG. 2B illustrates, on an enlarged scale, showing a transverse sectional view taken at line 2 B- 2 B in FIG. 2A ; [0034] FIG. 2C illustrates an axial view of the balloon showing the deployment of the stent of FIGS. 2A and 2B ; [0035] FIG. 3A illustrates, in a view similar to FIG. 2A , a modified embodiment of the stent and balloon delivery system; [0036] FIG. 3B illustrates an axial view of the positioning of the stent at the intended site thereof; [0037] FIG. 3C illustrates a transverse cross-sectional view of the stent and the balloon taken at line 3 C- 3 C in FIG. 3B ; [0038] FIG. 3D illustrates a side view of a modified balloon with a slit-tube structure; [0039] FIG. 3E illustrates a plan view of the structure of FIG. 3D ; [0040] FIG. 3F illustrates another modification in plan view with a catheter; and [0041] FIGS. 4A through 4H illustrate sequential steps in the deployment of the bifurcated stent structure through the intermediary of the balloon delivery system. DETAILED DESCRIPTION OF THE INVENTION [0042] Referring in detail to the drawings, and particularly FIGS. 1A to 1 C, there is illustrated a stent 10 , which may include a wavylinear strut design 12 along the axial length thereof. The stent 10 , which is radially expandable or contractable, includes a plurality of transverse strut connecting members 14 , and may be constituted of either a medically or biocompatible plastic material or a surgical grade metal; for example, such as Nitinol (nickel-titanium alloy), as is well known in the stent implanting technology. Furthermore, the stent 10 may also be equipped, coated or impregnated with a drug or antibiotic dispensing system or release layer, as is known and presently employed in the medical art technology. [0043] As illustrated in the drawings, a center region 18 of the stent 10 may possess a larger-sized open cell area 20 , in effect, fewer of the struts 12 , 14 in order to provide a larger opening 20 , as shown in particular detail in FIG. 1C of the drawings, and as elucidated hereinbelow. [0044] As indicated in the drawing FIGS. 2A through 2C , there is shown a composite or integrated stent and balloon delivery system 30 for deploying the stent 10 of FIGS. 1A through 1C in the lumen or body vessel of a patient. [0045] In particular, the system 30 , as illustrated in FIG. 2A , shows a balloon catheter 22 with either a central side guide wire exit location or site 24 , facilitating a previously placed guide wire 26 in a main branch of a bifurcated vessel or lesion of a patient to be loaded backwards into the central side guide wire exit 24 . A wire 28 at one distal end leads to a side branch and also wire 26 leads to the main branch in a bifurcated vessel or lumen of the patient through the side guide wire exit site formed in the stent 10 by the opening, which encompasses the periphery of the balloon 22 . [0046] At one end of the vessel, there is provided a dedicated exit point 34 for the second side guide wire 26 , as shown in FIG. 2A of the drawings, whereas the central wire 28 is extended continuously through the main or central lumen of the patient. [0047] As illustrated in FIG. 2A of the drawings, the second side exit wire 26 is shown exiting through the larger opening 20 in the stent 10 , which encompasses the balloon 22 , whereas the central wire 28 extends axially therethrough, as also shown by the cross-sectional view in FIG. 2B of the drawings. [0048] As represented in FIG. 2C of the drawings, which shows a top plan view of the system 30 , illustrating the larger aperture 20 formed in regions of the stent 10 through struts 14 , 12 , this shows the side or second side guide wire 26 being inserted therethrough and extending into the main branch of the patient's vessel, whereas the central wire 28 extends into the side branch. [0049] As shown in a modified version of the stent and balloon delivery system 40 , referring to FIGS. 3A through 3F of the drawings, in that instance, the wire 26 , which extends along to the main branch is directed through the larger aperture 20 in the stent 10 , which encompasses the balloon 42 , and then extends through a slit-tube 44 located at the outside surface 46 of the balloon 42 , towards an exit site 48 , whereas a central wire 28 extends through the balloon and the lumen of the patient arranged coaxially therewith. [0050] As shown in FIG. 3B of the drawings, the wire 26 , which leads to the main branch, extends through the larger sized opening 20 in the stent 10 , whereas the central wire 28 leads to the side branch in a generally alternative arrangement of the wires. [0051] As shown in FIG. 3C of the drawings, this illustrates in an enlarged transverse cross-sectional view, the central wire 28 extending axially and centrally through the balloon 42 stent 10 and the patient's lumen, whereas the other wire 26 extends through the slit-tube 44 , as shown in FIG. 3A of the drawings, and through aperture 20 in stent 10 outwardly into the main branch of the vessel. [0052] As indicated in FIG. 3C , this shows the central part of the tube 44 having been slit, enabling the wire 26 to exit along the slit portion and the site wire 26 being extended outwardly through the stent, whereas the other wire 28 extends centrally and axially through the balloon 42 , as is also illustrated in FIG. 3D of the drawings. [0053] Referring to FIG. 3E , this illustrates a top plan view showing the site wire 26 in the slit-tube 44 extending along the catheter, whereas the central wire 28 extends through the side branch of the bifurcated lumen, and the wire 26 from the slit-tube exits through the larger opening 20 in the center of the stent 10 , so as to enter into the main branch of the bifurcated lumen of the patient. [0054] As illustrated in FIG. 3F , in that instance, both wires 26 , 28 are arranged in the shaft 50 of the balloon catheter 52 , with one wire 26 extending upwardly through the large aperture in the stent to the main branch of the bifurcated vessel, whereas the other wire continues on through the balloon to the side branch. [0055] As illustrated in FIGS. 4A through 4H of the drawings, this illustrates the deployment steps in the method of positioning or siting of the stent 10 by means of the inventive stent deployment system (SDS). [0056] In this instance, implementation of siting the stent is effected in substantially the following manner: 1) There is initiated the placement of the two separate guide wires 26 , 28 into the main and side branches of bifurcated vessel, having reference to FIG. 4A . 2) The guide wire 26 in the side branch is loaded backwards into the central lumen, as represented in FIG. 4B . 3) The guide wire 28 in the main branch is loaded into the side-exit aperture/slit tube 44 and continued within the slit tube along the length or inside of the catheter shaft, referring to FIG. 4B . 4) The stent/balloon system is then advanced into the guide catheter with the two guide wires fixed in position. 5) The balloon/stent system is then advanced into the side branch until it is stopped by the guide wire, which was previously placed in the main branch and the position visually confirmed through fluoroscopy ( FIG. 4C ). 6) After carrying out of the visual confirmation, the balloon/stent is expanded and deployed in the side branch with the central larger open cell unit of the stent with the second guide wire residing in the main branch of the vessel of the patient ( FIG. 4D ). 7) The balloon in the expanded side branch is then deflated and withdrawn. 8) A similar balloon/stent is then loaded, this time with the central lumen loaded backwards using the guide wire in the main branch and the side-branch guide-wire loaded into the side exit or slit-tube, which is located on the side of the stent/balloon outer surface. 9) The second stent/balloon system is then advanced in a similar manner, as previously described in steps 4) and 5), except that the stent/balloon system is advanced into the main branch until it is stopped by the guide wire located in the side branch, and the position thereof visually confirmed by fluoroscopy ( FIG. 4E ). 10) After completing the visual confirmation, the balloon/stent is expanded and deployed in the main branch with the central larger open cell unit of the stent with the second guide wire centered in the side branch of the vessel ( FIG. 4F ). The balloon is then deflated and removed by being withdrawn ( FIG. 4G ). 11) Following inflation/deployment of the second stent/balloon system, two balloons with same or different sizes can then be advanced into place and simultaneous balloon inflation performed so as to maximize stent lumen and improve stent surface contact with the vessel wall. Herein, two stent layers are shown in the bifurcated vessel ( FIG. 4H ). 12) The balloon is then deflated and removed for angiographic examination of the treatment site. [0069] From the foregoing, it becomes clearly obvious that the invention is directed at a unique stent and balloon stent delivery system, which is adapted particularly for but not limited to the treatment of bifurcated vessels and lesions in a patient, and also may be utilized for single lumens at various locations in a patient's body and for diverse treatments analogous to those currently employed in the technology. [0070] While the invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
A stent and a percutaneous balloon system for the placement of the stent in the lumen of a patient, and particularly relates to a stent and balloon system, which may be an integrated delivery system for dilatation and/or placement of a stent or stents especially for but not limited to bifurcated vessels and lesions. Moreover, disclosed is a method of deploying the stent at a particular site through the intermediary of the inventive balloon system.
0
CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. patent application Ser. No. 09/621,092 filed on Jul. 21, 2000 which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Applications No. 60/145,464 filed Jul. 23, 1999 and 60/206,123 filed May 22, 2000, all of which are incorporated by reference herein in their entirety. FIELD OF THE INVENTION The present invention is in the field of inhalers. BACKGROUND OF THE INVENTION In the early 1970's it was found that certain medicines could be administered in dry-powder form directly to the lungs by inhalation through the mouth or inspiration through the nose. This process allows the medicine to bypass the digestive system, and may, in certain cases, allow smaller does to be used to achieve the same results or orally ingested or injected medicines. In some cases, it provides a delivery technique that reduces side effects for medicines taken by other medicines. Inhaler devices typically deliver their medicinal in a liquid mist or a powder mist. The liquid mist is typically created by a chlorofluorocarbon propellant. However, with the ban on chlorofluorocarbons by the Montreal protocol, interest has turned to dry powder inhalers. For a dry powder inhaler to work effectively, it must deliver fine particles of medicinal powder that do not agglomerate, and do not end up striking, and being absorbed by the patient's mouth or upper oropharyngeal region. Air flow must therefore not be too fast. Furthermore, it should not be difficult for a patient to load with medicine or to use with the proper technique. Current dry particle inhalers fail in one or more of these important criteria. SUMMARY OF THE INVENTION Described is a dry powder inhaler comprising an intake section; a mixing section, and a mouthpiece. The mouthpiece is connected by a swivel joint to the mixing section, and may swivel back onto the intake section and be enclosed by a cover. The intake chamber comprises a special piston with a tapered piston rod and spring, and one or more bleed-through orifices to modulate the flow of air through the device. The intake chamber further optionally comprises a feedback module to generate a tone indicating to the user when the proper rate of airflow has been achieved. The mixing section holds a capsule with holes containing a dry powder medicament, and the cover only can open when the mouthpiece is at a certain angle to the intake section. The mixing section further opens and closes the capsule when the intake section is at a certain angle to the mouthpiece. The mixing section is a Venturi chamber configured by protrusions or spirals to impart a cyclonic flow to air passing through the mixing chamber. The mouthpiece includes a tongue depressor, and a protrusion to contact the lips of the user to tell the user that the DPI is in the correct position. An optional storage section, with a cover, holds additional capsules. The cover for the mouthpiece, and the cover for the storage section may both be transparent magnifying lenses. The capsules may be two-part capsules where each portion has apertures which correspond to apertures in the other half when each half is partially fitted to the other half, and fully fitted to the other half. All the apertures may be closed when the two halves are rotated around their longitudinal axes with respect to each other. Each capsule may have a unique key on each half that only fits with a particular inhaler. Therefore it is an object of the invention to provide a dry particle inhaler that can fold into a compact form. Therefore it is an object of the invention to provide a dry particle inhaler that can be loaded with medicament easily. Therefore it is an object of the invention to provide a dry particle inhaler where the small writing on a capsule of medicament can be easily read. Therefore it is an object of the invention to provide a dry particle inhaler where a capsule containing medicament can only be inserted when a person unfolds the inhaler for use. Therefore it is an object of the invention to provide a dry particle inhaler where the air flow through the device is regulated. Therefore it is an object of the invention to provide a dry particle inhaler to provide a means for indicating to the user when the air flow is at the correct rate. Therefore it is an object of the invention to provide a dry particle inhaler where particles of drug are dispersed finely. These and other objects of the invention will be readily apparent upon a reading of the present specification, claims and drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a schematic view of the dry particle inhaler described herein. FIG. 2 is schematic view of the mouthpiece cover. FIG. 3 is schematic view showing the angle between the intake section and the mouthpiece. FIG. 4 is a schematic view of the dry particle inhaler, showing the storage section. FIG. 5 is a schematic view of the intake section of the dry particle inhaler, showing the flow regulator and the feedback module. FIG. 6 is a schematic view of the mixing section. FIG. 7 is a schematic view of a capsule to hold medicament. FIG. 8 is a schematic view of the mouthpiece. FIG. 9 is a perspective view of a specific embodiment of the dry particle inhaler in the closed position, with a capsule inserted into the mixing section, and extra capsules stored in the storage section. FIG. 10 is a perspective view of a specific embodiment of the dry particle inhaler showing a capsule being loaded in to the mixing section. FIG. 11 is a perspective view of a specific embodiment of the dry particle inhaler showing a capsule inserted into the mixing section, and the mouthpiece extended for use. FIGS. 12 , 13 , 14 , and 15 follow each other in temporal sequence. FIG. 12 is a perspective view of a specific embodiment of the dry particle inhaler showing a closed mouthpiece cover. FIG. 13 is a perspective view of a specific embodiment of the dry particle inhaler showing an open mouthpiece cover. FIG. 14 is a perspective view of a specific embodiment of the dry particle inhaler showing an open mouthpiece cover, an open mixing section cover, and a capsule about to be inserted into the mixing section. FIG. 15 is a perspective view of a specific embodiment of the dry particle inhaler showing the mouthpiece extended for use. FIG. 16 is a view of a pneumatic circuit, where air flows (fluid flows) are represented by their electrical equivalents. FIG. 17 is a schematic view of the dry particle inhaler. FIG. 18 is a cutaway view of a capsule and a portion of the mixing section. FIG. 19 is a cutaway view of half of a capsule, showing a cone in the interior and a secondary hole with a chamfered, or beveled, edge. TABLE OF REFERENCE NUMBERS 10 dry powder inhaler device 20 intake section 30 mixing section 40 mouthpiece 50 air passage through dry powder inhaler device 60 longitudinal axis of intake section 70 longitudinal axis of mouthpiece section 80 swivel joint connecting mouthpiece and mixing section 90 cover for mouthpiece 100 protrusions on mouthpiece cover 110 depressions on dry particle inhaler cover to mate with protrusions on mouthpiece cover 120 tongue depressor on mouthpiece 130 protrusion on surface of mouthpiece to contact lips of device user 135 opening of mouthpiece to be fitted into user's mouth 140 intake port 150 flow regulator 160 bleed orifice 170 piston 180 piston head 190 piston rod 200 proximal portion of piston rod 210 distal portion of piston rod 220 spring 230 inner walls of intake section inner chamber 240 feedback module 250 mechanical fasteners in storage section 260 holder in mixing section for capsule 270 Venturi chamber 280 spiral shape or protrusions to impart cyclonic flow to air 290 cover for mixing chamber 291 interior of mixing section 292 air flow entrance to mixing section 294 air flow exit from mixing section 296 latch mechanism for mixing section cover 298 interior wall of mixing section 300 capsule 310 first tube 320 open end of first tube 330 closed end of first tube 340 long axis of first tube 350 protrusion on first tube 360 keying surface on first tube 370 secondary holes in first tube 372 chamfered edge of secondary hole 375 cone in interior of first tube 380 second tube 390 open end of second tube 400 closed end of second tube 410 long axis of second tube 420 protrusion on second tube 430 keying surface on second tube 440 secondary holes in second tube 445 cone in interior of second tube 450 hand of user 460 air flow direction 470 storage section 480 storage section cover DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a schematic drawing of the dry powder inhaler ( 10 ) described herein. It comprises an intake section ( 20 ), a mixing section ( 30 ) and a mouthpiece ( 40 ). An air passage ( 50 ) goes through the intake section ( 20 ), a mixing section ( 30 ) and a mouthpiece ( 40 ). A swivel joint ( 80 ) connects the mouthpiece ( 40 ) to the mixing section ( 30 ). The mixing section ( 20 ) has a cover ( 290 ) which may be a transparent magnifying lens. Arrow ( 460 ) shows the direction of air flow through the air passage ( 50 ) through the dry powder inhaler ( 10 ). FIG. 2 shows the mouthpiece cover ( 90 ) in the closed position over the dry particle inhaler ( 10 ). Protrusions ( 100 ) on the mouthpiece cover ( 90 ) mate with grooves or depressions ( 110 ) on the dry particle inhaler ( 10 ), to join the mouthpiece cover ( 90 ) to the dry particle inhaler ( 10 ). FIG. 3 is a schematic of the showing the mouthpiece ( 40 ) and the intake section ( 20 ) as represented by the longitudinal axis of the mouthpiece ( 70 ) and the longitudinal axis of the intake section ( 60 ). The swivel joint ( 80 ) connecting the mouthpiece ( 40 ) to the intake section ( 20 ) at the mixing section ( 30 ) may be regarded as the vertex of the angle. The importance of the angle (here called theta) between these two longitudinal axes will be further explained. FIG. 4 shows the dry particle inhaler ( 10 ) with a storage section ( 470 ). Indicated as being inside the storage section ( 470 ) are mechanical fasteners ( 250 ) which operate to hold medicament capsules ( 300 ) (not shown in this Figure) in the storage section. In this embodiment, the storage section ( 470 ) is shown as appended to the intake section ( 20 ). The storage section has a cover ( 480 ) which may be a transparent magnifying lens, to allow the user to easily read writing on medicament capsules stored therein. The storage section cover ( 480 ) may swivel outward, or slide open on a track (not shown), or open by a variety of mechanisms known to those of skill in the art. FIG. 5 shows the intake section ( 20 ) of the dry particle inhaler ( 10 ). The direction of air flow is shown by the arrow ( 460 ). Air is admitted through an intake port ( 140 ) and one or more bleed orifices ( 160 ) [The bleed orifices may also be styled as secondary ambient air intake ports]. The piston ( 170 ) normally covers the intake port ( 140 ). When the user (not shown) inspires, the piston head ( 180 ) is drawn backwards, at a steady rate modulated by the spring ( 220 ). The spring ( 220 ) is fixed to the piston ( 170 ) and the inner wall ( 230 ) of the intake section chamber. Thus the rate of air flow is controlled. The air flow is further controlled by the tapering of the piston rod ( 190 ), past which the air flows. For further control of the air flow, a second spring (not shown) may also control the rate of movement of the piston ( 170 ). The piston ( 170 ) and spring ( 220 ) combination allow the user (not shown) to generate a vacuum in his lungs before the intake port ( 140 ) opens. Thus, by the time enough vacuum is generated to open the intake port ( 140 ), there will be sufficient air flow at a sufficient rate in the dry particle inhaler ( 10 ) to draw most of the medicament in the capsule (not shown) out of the inhaler into the proper place in the lungs of the user. A feedback module ( 240 ) generates a signal to the user (not shown), which tells the user whether he is inspiring at the correct rate. The signal may be an audible one, in one embodiment a tone that is at a steady pitch when air flow is at a certain steady rate. In one embodiment of the dry particle inhaler ( 10 ), the signal is generated mechanically, such as be a musical reed. In another embodiment of the invention, the signal might be generated electronically, after electronic measurement of the air flow rate. The feedback module ( 240 ) would include a means for increasing or lessening the signal strength, or turning the signal off entirely. If the signal were generated by a reed, the mechanism for turning off the signal might be covering a bleed orifice which might admit the air flow generating the signal. If the signal were generated electronically, a simple push button or dial might turn on and off the signal. FIG. 6 shows a schematic of the mixing section ( 30 ) of the present invention. The mixing section has a cover ( 290 ), and a holder ( 260 ) for a medicament capsule (not shown). The holder ( 260 ) is a mechanism which grips and turns the capsule (not shown) to open and close it as the longitudinal axis ( 70 ) of the mouthpiece is rotated about the swivel joint ( 80 ) relative to the longitudinal axis ( 60 ) of the intake section. Such a mechanism may be straightforward: in a simplest embodiment, both the top and bottom halves (not shown) of the capsule could be fixed to their respective holders ( 260 ). The Venturi chamber ( 270 ) speeds the flow of air near the capsule (not shown). Air flows in at ( 292 ), and out through ( 294 ). In one embodiment, air flows both through and around a capsule (not shown) holding a dry powder medicament. The special shape of the Venturi chamber ( 270 ), which further includes protrusions or spiral shapes ( 280 ), imparts a cyclonic flow to the air passing through the mixing section ( 30 ). This helps to de-agglomerate particles of dry powder. The spiral shape of the interior of the mixing section ( 291 ) can be two separate spirals, in one embodiment of the invention. Mixing section ( 30 ) therefore provides the means whereby air flow is speeded up to suspend dry particles in air and de-agglomerate them, and then slow the air flow somewhat while the particles are still suspended in air. The cover ( 290 ) for the mixing section ( 30 ) may be a transparent magnifying lens, so that any writing on the capsule (not shown) may be read easily. In one embodiment of the dry particle inhaler ( 10 ), the cover ( 290 ) of the mixing section may not be opened unless the longitudinal axis ( 70 ) of the mouthpiece forms a certain angle with the longitudinal axis ( 60 ) of the intake section, with the vertex of the angle being the swivel joint ( 80 ) connecting the mouthpiece ( 40 ) and the mixing section ( 30 ). The latch mechanism ( 296 ) for the cover ( 290 ) of the mixing section can accomplish this, by any of several mechanical means known to those of ordinary skill in the art. In the simplest embodiment, a catchment (not shown) in the cover ( 290 ) for the mixing chamber would be engaged by a slip ring (not shown) on the mixing section which was only a certain number of degrees of a circle. When the mouthpiece ( 40 ) were rotated enough relative to the intake section ( 20 ), the slip ring (not shown) would no longer engage the catchment (not shown). In one embodiment, the user could open the cover ( 290 ) when the angle were between approximately ninety and one-hundred and eighty degrees. FIG. 7 shows a medicament capsule ( 300 ) for use with an inhaler, be it a dry powder inhaler ( 10 ), or a liquid mist inhaler. The capsule ( 300 ) has two halves which fit together, here styled a first tube ( 310 ) and a second tube ( 380 ). Each tube has an open end ( 320 , 390 ), and a closed end ( 330 , 400 ). Each tube also has a long axis ( 340 , 410 ). In addition, each tube has a number of secondary holes ( 370 , 440 ). The first tube ( 310 ) fits inside the second tube ( 380 ) snugly. A protrusion ( 350 ) on the outer surface of the first tube ( 310 ) can slide past a corresponding protrusion ( 420 ) on the inner surface of the second tube ( 380 ). This locks the first tube ( 310 ) to the second tube ( 380 ). Therefore the first tube ( 310 ) and the second tube ( 380 ) have both an unlocked and a locked position. In the unlocked position, at least one secondary hole ( 370 ) in the first tube aligns with at least one secondary hole ( 440 ) in the second tube. This permits introduction of a medicament (not shown) into the capsule through the aligned secondary holes ( 370 , 440 ). The first tube ( 310 ) may then be locked to the second tube ( 380 ). When a user (not shown) is ready to use a capsule ( 300 ), he simply places it in the holder ( 260 ) in the mixing section ( 30 ), and closes the cover ( 290 ). When the holder ( 260 ) rotates the first tube ( 310 ) around its long axis ( 340 ) relative to the second tube ( 380 ) and its long axis ( 410 ) (the axes are now coincident), that causes at least two secondary holes ( 370 ) in the first tube to align with at least two secondary holes ( 440 ) in the second tube. Air can now pass in, through, and out of the capsule ( 300 ), releasing the medicament contained therein. In one embodiment of the inhaler, the capsule ( 300 ) might open when the angle between the longitudinal axis ( 70 ) of the mouthpiece section, the vertex of the swivel joint ( 80 ), and the longitudinal axis ( 70 ) of the mouthpiece section were between one hundred and seventy and one-hundred and eighty degrees. This rotation of the mouthpiece ( 40 ) relative to the intake section ( 20 ) would cause a corresponding rotation of the first tube ( 310 ) about its long axis ( 340 ) relative to the second tube ( 380 ) and its long axis ( 410 ). In one embodiment of the invention, several protrusions on the surfaces of the first tube or the second tube might provide a variety of locking positions. Similarly, a variety of secondary holes in the first and second tubes might provide a variety of rotational positions aligning or not aligning secondary holes on the first and second tubes. The capsules described herein permit the introduction of liquid or gel medicament which can be dried in the capsule, creating a powder. This permits the accurate production of very small amounts of powdered medicament in a capsule, since it can be formed from a larger volume of accurately metered liquid or gel medicament. This permits very accurate microdosing. In addition, chemical reactions and drug mixtures may be made directly in the capsules described herein, then the resulting formulation dried. In one embodiment of the capsule ( 300 ), one or more of the secondary holes ( 370 , 440 ) used to admit air to the capsule is oval-shaped (elliptical). In one embodiment of the invention, the ratio of the long axis of the ellipse to the shorter axis may be between 1:1 and 3:1, and may be 2:1. This ratio may be called a vertical aspect ratio. In one embodiment of the invention, the intersection of the surface defining one or more of the secondary holes ( 370 , 440 ) and the surface defining the interior of the capsule ( 300 ) meet in a chamfered, or beveled, edge. This chamfered edge creates a vortex when air flows through the secondary holes ( 370 , 440 ). Each capsule ( 300 ) also has a keying surface (or fastening mechanism) on the closed end ( 330 ) of the first tube and the closed end ( 400 ) of the second tube comprising the capsule. The keying surface ( 360 ) on the first tube may be different from the keying surface ( 430 ) on the second tube. That permits easy tactile and visual identification of the orientation of the capsule. It also permits a system where each drug formulation in a capsule ( 300 ) corresponds to a dry particle inhaler ( 10 ), so users cannot mix up drugs. In one embodiment of the invention, the keying surface ( 360 ) of the first tube mates with a keying surface ( 430 ) of a different second tube, or the mechanical fasteners ( 250 ) of the storage section ( 470 ). This permits easy storage of the capsules ( 300 ) in the storage section ( 470 ). FIG. 18 shows a medicament capsule ( 300 ), with a keying surface ( 360 ) on the first tube and a keying surface ( 430 ) on the second tube. It also shows a cutaway view of the mixing section ( 30 ) and the air flow entrance ( 292 ) to the mixing section and the air flow exit ( 294 ) to the mixing section. A spiral shape ( 280 ) is given to the interior walls ( 298 ) of the mixing section, to impart a cyclonic flow to air passing through. The air flow entrance ( 292 ) and air flow exit ( 294 ) in this embodiment are tangential to the imaginary tube we might call the mixing section interior ( 291 ). That is to say, if a radius were drawn perpendicular to the long axis of the tube, and a tangent line were drawn to the circle perpendicular to the radius, the air flow would exit the mixing section along that tangent line. The tangential air flow exit ( 294 ) increases the velocity of the air flow, and thus helps disperse the medicament particles. As can be seen from FIG. 18 , the mixing section interior ( 291 ) is sized to accommodate a medicament capsule ( 300 ). Keying mechanisms ( 360 , 430 ) are shaped to mate with holder ( 260 ) in the mixing section. Capsules according to the present invention may have a number of shapes, including ovoid and rectangular shapes. A variety of shapes of protrusions and slots may also be employed as keying surfaces. For instance, a keying surface might be a rectangular block, and a capsule holder might have a rectangular orifice. Alternatively, a keying surface might be triangular, hexagonal, Z-shaped, C-shaped, etc., and the holder would have the correspondingly shaped aperture. FIG. 18 also shows one embodiment of the capsule ( 300 ) where a cone ( 375 ) is located in the interior of the first tube, and a cone ( 445 ) is located in the interior of the second tube. These cones ( 375 , 445 ) cause the air flow within the capsule to be cyclonic, aiding in mixing the medicament particles with the air. A cone is shown herein, but other cyclone-creating structures are contemplated by the present invention. FIG. 8 shows the mouthpiece ( 40 ) of the dry particle inhaler ( 10 ). It has a protrusion ( 130 ) on its surface to contact the lips of a user (not shown). This helps the user place the mouthpiece correctly in his mouth. The mouthpiece ( 40 ) also includes a tongue depressor ( 120 ), which may have a bulbous shape. The mouthpiece ( 40 ) is long enough that it fits approximately midway into the user's mouth (not shown). This permits greater delivery of medicament to the lungs, and less delivery to the oral cavity. The mouthpiece ( 40 ) has a particular aspect ratio of its inner channel ( 50 ) (see FIG. 17 ). This slows the air passing through the channel so that the air borne particulates do not end up striking the back of the user's throat. However, the air is not slowed so much that the particulates settle out of the air flow. FIG. 9 , FIG. 10 , and FIG. 11 show one specific embodiment of the dry particle inhaler ( 10 ). In FIG. 9 , the cover ( 90 ) of the mouthpiece is closed, and several capsule ( 300 ) are in the storage section ( 470 ). In FIG. 10 , the mouthpiece ( 40 ) has been rotated relative to the intake section ( 20 ). The longitudinal axis ( 60 ) [not shown] of the intake section here makes an approximately ninety degree angle with the longitudinal axis ( 70 ) of the mouthpiece section. This permits the cover ( 290 ) for the mixing section to be opened. A medicament capsule ( 300 ) taken from the storage section ( 470 ) is about to be inserted into the mixing section ( 30 ). In FIG. 11 , the mouthpiece ( 40 ) has been rotated to a fully extended position, the cover ( 290 ) for the mixing section has been closed, and the dry particle inhaler 910 ) is ready for use. In one embodiment of the dry particle inhaler ( 10 ), when the dry particle inhaler is in the closed position ( FIG. 9 ), the interior of the intake section ( 20 ) would be isolated from the outside air, but the mouthpiece ( 40 ) interior and the mixing section interior ( 291 ) would not be, permitting them to dry out after being exposed to the humid breath of a user. FIG. 12 , FIG. 13 , FIG. 14 , and FIG. 15 show a temporal sequence where a capsule ( 300 ) of medicament is loaded into the mixing section ( 30 ) of a dry particle inhaler ( 10 ), and the mouthpiece ( 40 ) is extended for use. The dry particle inhaler ( 10 ) described herein can also be used for nasal delivery of medicaments. A small tube (not shown) can be fitted to the end of the mouthpiece ( 40 ), and the other end of the tube inserted into the nostril. Alternatively, the mouthpiece ( 40 ) may be replaced by a nosepiece (not shown), whose free end is sized to be inserted into a nostril of a user. In another embodiment, a device such as a bellows or a syringe is used to force air through the dry particle inhaler ( 10 ) into a nosepiece inserted into the nostril of a user (not shown). FIG. 16 shows the fluid (air) flow of the dry particle inhaler ( 10 ) modeled as the equivalent electrical circuit. This is styled a “pneumatic resistance circuit”. FIG. 17 shows a schematic view of the dry particle inhaler ( 10 ). The air passage ( 50 ) through the dry particle inhaler widens as it goes through the mouthpiece ( 40 ) along the direction of the air flow ( 460 ). The opening ( 135 ) of the mouthpiece to be inserted into the mouth of the user may be roughly ellipsoid, or oval, and thus have a major axis and a minor axis. The ratio of these two may be called the horizontal aspect ratio. In one embodiment of the invention, the horizontal aspect ratio is between 2:1 and 4:1. In one embodiment of the dry particle inhaler ( 10 ), the horizontal aspect ratio is 3:1. Shaping the opening ( 135 ) in this manner keeps the drug particles collimated, maintains the optimal velocity of the particles in the air stream, and is oriented to the natural horizontal aspect ratio of the oropharyngeal region of the mouth. In one embodiment of the invention, the outline of the opening ( 135 ) resembles a bean. The dry particle inhaler described herein may be used with medicament particles of low, medium, and high shear forces. The dry particle inhaler and capsules described herein may be made with a variety of suitable materials known to those skilled in the art, such as metal, glass, rubber, and plastic. While the invention has been described with reference to particular embodiments, those skilled in the art will be able to make various modifications without departing from the spirit and scope thereof.
Described are dry powder inhalers comprising an intake section, a mixing section and a mouthpiece. The mixing section can accommodate a capsule having a top keying portion and containing a dry powder medicament. The top keying portion of the capsules may fit within complementary keying structures in inhaler mixing sections.
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FIELD OF THE INVENTION [0001] The present invention relates to the field of human and animal diagnostic and treatment procedures for the Lyme Disease pathogens including Borrelia burgdorferi , et. al. More specifically this invention offers a methodology to improve the accuracy of the results of most Lyme testing technologies presently available. Treatment procedures may also be enhanced with the BPP. BACKGROUND Lyme Disease Background [0002] Borrelia burgdorferi (Bb) is utilized herein as a generic term which encompasses several Borrelia species associated with, and believed to be, the causative agent of Lyme borreliosis (Lyme disease): B. burgdorferi sensu stricto, B. garinii , and B. afzelii , et. al. This disease is transmitted by the bite of various species of Ixodes ticks carrying the spirochete. The main reservoir of the infection in the United States is the white footed mouse, Peromyscus leucopus , and the infection can be transmitted to many mammalian species including deer, dogs, cats, and humans [0003] The first and foremost problem with Lyme disease is accurate diagnosis. There are reasons for these difficulties in diagnosis. To start, the initial bite of an infected tick may go unnoticed by the patient, and then the clinical manifestations of Lyme disease can significantly vary among diagnosed patients. Common general symptomatology such as fever, malaise, and arthritis can resemble the symptoms caused by many other conditions, further complicating an accurate and timely diagnosis. [0004] The second reason contributing to difficult diagnosis of Lyme disease is that the primary traditional diagnostic method currently available is limited to detecting Lyme Borrelia antibodies which, in general, is retrospective and of little use to treating patients in acute-phase states (to be explained). Complicating the immune reaction specifically is that this infective agent sometimes invades the immunoglobulins themselves, rendering detection of an immune response utilizing antibodies impossible. Further complicating testing despite the presence of an active immune response, the disease can persist for years in patients unless it is treated early. Such persistence is postulated to be the result, at least in part, of antigenic variation in the bacterial proteins. In many cases this persistence is assumed to be from repeated exposures (infective tick bites). [0005] The accurate diagnosis of Lyme disease in humans and animals has been compromised by the lack of definitive serology (blood testing) which should lead to rapid and accurate diagnosis, but does not. The current generally accepted diagnostic tests suffer from low sensitivity and specificity, as illustrated by a recent survey of diagnostic laboratories performance issued by the Wisconsin State Laboratory of Hygiene. A simple, sensitive and specific diagnostic methodology, and a useful serologic method of testing for the early detection of Lyme disease is presently lacking but is really needed within the art to apply effective treatments. [0006] In addition, antibiotic therapy is highly effective, especially if administered in the early stages of infection of Lyme disease, much more than late stage infections. Early and accurate diagnosis is necessary to allow this standard therapy to work. However, serious complications can result from a missed diagnoses and inappropriate treatment. Also, there is no commercially available or useable vaccine for human Lyme disease, so the development of accurate and sensitive laboratory diagnosis is an important goal of Lyme disease research as prevention is impossible. The longer the infection is in the system, the more difficult it becomes to eliminate. [0007] Lyme Disease is the 6 th fastest growing disease in the country (Possibly the 3 rd fastest taking into consideration new CDC data reports). To date, there are no consistently reliable, non-invasive and affordable testing methods. The disease is difficult to diagnose on symptoms alone due to variations in symptom patterns. [0008] Treatment offered beyond the 7th day from the initial infection period shows more relapse responses and bacterial resistance to treatment. As time goes by, treatability becomes progressively more difficult. These spirochetes adapt to chemical (antibiotic) assault with adaptive genetic coding shifts, and maintains the information for future generations. The spirochetes are even known to have migrated to the central nervous system before the erythema migrans rash erupts. [0009] Spirochetes will also rapidly congregate in tendons and joints, making it more and more difficult to access the pathogen for testing as it moves deeper into tissues over time. This pattern also makes it exceptionally difficult to eradicate when the Borrelia moves into these non-vascular synovial fluids and nervous tissues with the treatment of blood borne antibiotic treatments. [0010] Difficulties with proper detection remain an issue with the testing protocols presently recommended by the CDC, which has a serum only requirement, and utilizes the Western Blot and ELISA as their base standard. [0011] The Lyme spirochete's natural mode of operation is to undergo alterations in their physical form (DNA) within the tick before transmission. The spirochetes change their genetic structure to adapt to the present carrier species as well. As it lives within a carrier, it will modulate its form utilizing the extra DNA fragments it carries to avoid immune detection. This is beyond epigenetic adaptability. These factors make it very difficult to accurately test antibodies and antigens with these variable triggers. [0012] If the infected tick implantation is successful, it takes the tick born spirochetes 24 hours to identify this host, alter its DNA and transfer to the host mammal. After transfer, they will peak in numbers 60 days into the infection and then drop by a factor of 1000 making them almost impossible to detect there after within the blood. This is a public health issue as many people are not even aware of the tick bite and the time line associated with it. [0013] Established research has shown the Borrelia organisms are present in very small numbers in the body, and are often sequestered in hard to reach places that require biopsy. Antibodies are sometimes so low or non-existent in infected individuals that they do not show positive in blood tests. Antibodies create other confusion in accurate diagnosis because they can continue to be produced, even if the infection has been eradicated. [0014] A more difficult and impractical solution for the issue of Lyme disease will be the formulation of a vaccine to prevent this infection. The DNA structure varies and adapts to the species quickly, making it nearly impossible to create an effective human vaccine, without creating a variant of the disease or autoimmunity, which was a problem with previous attempts. Needle transmission of the isolated spirochetes creates a very different serum antibody response than a natural tick bite transmission. There is also an extremely small immune response to the spirochete alone. [0015] Rapid treatment is the most viable and effective defense at this time. Several antibiotics work very effectively when treatment is prompt relative to the infection onset. If there are no active Lyme Borrelia spirochetes, Lyme treatment protocols are not indicated, and alternative diagnosis procedures are indicated. [0016] If the white blood cells themselves become infected with the spirochete, an immune response does not occur at all. Since there is tick saliva present with transmission, leukocyte (immune response) activity becomes suppressed by the saliva itself. As a result the ELISA test is quite unreliable as it is only testing certain antibodies. [0017] The antibody schedule that typically will occur is as follows: Week 2-4—½ of people infected will produce antibodies, only to disappear by week 8 IgM antibodies rise during the third week, peak at week 4-6 and disappear at week 8 IgG antibodies can persist for years or decades, creating false positives even if there is no active infection. [0021] A second bite seems to change this classic timing patterns. The peak in this case is around day 6 (according to species and organ load measured). Secondary tick bites seem to convey a certain amount of immunity and do not always stimulate a flair of immune responses or infection symptoms. Choosing and using the right antibody mediated testing procedure at the right time seems impractical. [0022] These are significant problems impeding accurate detection of Lyme disease infection, and therefore proper treatment. [0023] Only extremely healthy people with very healthy immune systems can produce antibodies to the tick saliva to inhibit future tick implantation, or produce tick rejection. The more immune compromised an individual is, including simple generalized stress response, the more likely it is that infection will take place, the antibiotics can fail, and there will be a relapse into so called, long-term Lyme syndromes. [0024] The Western Blot has its own issues, as much of the test depends on antibody reactive band activity from any flagella from any form of spirochete and is not Lyme specific so it can also include all Treponema spirochetes, including those that cause syphilis, yaws and periodontal infections. [0025] Unfortunately the Western Blot and the ELISA tests are presently the gold standard of Lyme testing in the field, primarily because they utilize blood as the testing source. The commercial labs and hospitals and so forth tend to use one antigen test, when there are many, and they are notoriously under-diagnosing Lyme disease due to this lack of consistency. False negative testing can lead the patient being up to 20 years on the wrong treatment pathway medically. Related Lyme Borrelia Behavior Background [0026] The scientifically established and determined normal behavior of the Lyme Borrelia spirochete is the key focus of this procedure. When there is a behavior that has a stimuli and response action, it becomes artificially manipulable. Manipulating the natural behavior of the Lyme spirochete makes it more precisely testable. [0027] The Lyme Borrelia organism is one of the most adaptable and changeable organisms on the planet. This spirochete can rapidly change its genetic structure to adapt and respond to any environmental pressure. For example, when the spirochete is being starved by its tick host it has the extreme morphic ability to change into an encysted form within one minute of being genetically expressed in order to await a more favorable environment or host (up to ten months). They can do this as a result of possessing and utilizing the largest number of optional genetic units of replication of any bacteria known. [0028] Though all Borrelia groups are classified as spirochete bacteria, they behave as exceptionally intelligent protozoa. Having predictable behaviors makes it possible to manipulate these spirochetes. The traditional approaches to manipulating or controlling bacteria with antibiotics or vaccines does not work as well as hoped for with these organisms as they also possess a unique flexibility in that they can rearrange their genetic structure appropriately through chemotaxis to avoid detection and create resistance. (Chemotaxis=the detection of minute changes of the chemistry of their environment). These spirochetes also have a great ability for multi-drug efflux as they become exposed to new treatment medications. (Efflux=organism develops the ability to have the killing drugs flow out of them before they can do harm). With this disease, it is uniquely important to manipulate and control these reactions to rapidly and effectively detect and treat the infection when the pathogen is vulnerable. [0029] All Borrelia spirochetes also utilize chemotaxis for monitoring and adapting to the changing worlds it can live in. It extends survival. For example, chemotaxis is used to detect when the spirochete's host (tick) is feeding, as well as identification of what species it is feeding upon. There are 24 extra segments of DNA available for the spirochete's use at any time to adapt to a new host's environment. This is dependent upon the detection and identity of the DNA of the tick's new and future host (mammal), as detected by the spirochete through the host blood upon which the tick is feeding. [0030] The Lyme Borrelia then will sort out which strands will be utilized, and the organisms communicate with each other to modulate the correct variations of DNA strands to ensure the greatest survival in the new host, splicing in the new variables. These DNA strands contain information on how to make changes to the Lyme Borrelia 's own physiology to evade that mammal host's immune system. This Borrelia strain will hold that memory for future generations to use as well. When that configuration is internally calculated, the spirochetes triple to quadruple their population in preparation for transfer to the mammal host. As prior arts have established, 154 genes in all are altered in this process (75 are up-regulated and 79 are down-regulated). Thirty-seven changes occur in the outer protein membrane alone, as discovered thus far. These are extremely difficult parameters when considering vaccines, tests, and treatments. The variations are almost limitless. [0031] At this stage the spirochetes are within the saliva of the tick vector. The Lyme Borrelia moves into the mammalian host through this exchange of blood and saliva. It genetically alters itself once again as a group to penetrate the epithelial tissues, creating more collagenolytic, fibrinolytic and proteolytic products beyond the activity of just the tick saliva to facilitate this process. Once cloaked in its invasive identity, the spirochetes move slowly through the blood of the mammal host, seeking collagenous and dense tissues. The Bb as all Borrelia share the same dislike of blood and the same affinity for dense collagenous tissues. They move even faster in collagen than in blood. Some of the densest tissues are across the blood brain barrier. This is why within days of infection Lyme can be detected in the central nervous system of the host and in the aqueous humor of the eyes. The organism can be detected soon after that, in and around joints in the synovial fluid, evading immune and pharmaceutical attack, because it has already left the blood-rich tissues. [0032] The solution starts with the tick's participation. When any growth stage of a tick vector starts to feed, it alternates between ingesting blood and secreting saliva into the wound it produces. The saliva is composed of a complex blend of powerful, pharmacologically active compounds, designed to bypass the host immune system and awareness as well as to prevent clotting. As soon as the new tick begins releasing this unique blend of chemicals and bio-factors into the blood stream of the mammal host with its saliva, the Lyme Borrelia in the tick begin transforming in preparation for transfer. [0033] The genetic expression of adaptability continues once the spirochete is in the mammal's human's system. The Lyme Borrelia will adjust and adapt continuously to the individual person's body and immune system to better survive over time. The offspring are extremely well adapted to live in that particular person or organism as generations reproduce. Lyme Borrelia reproduce themselves every 8-12 hours (unlike most bacteria which is every 20 minutes). The replication period for this bacterial invasion is much slower, but more effective than other bacteria in consideration of these genetic modifications. [0034] Lyme Borrelia will also create a defensive reaction on the genetic scale, releasing a “bleb” of DNA material to distract the host's immunoglobulin reactive system long enough for the Bb to transmute their own DNA to express differently. The sensitivity of the Lyme Borrelia spirochete allows them to detect the tiniest alterations in the surrounding environment and respond almost immediately through chemotaxic detection and genetic alteration. The same chemotaxic process is at work when the spirochete living in the host mammal encounters another tick implantation. [0035] This is the final and most relevant biological and behavioral manifestation of the spirochete. Once tick saliva factors are sensed by existing spirochetes within a tick's mammalian host, the spirochetes immediately enter the blood stream from wherever they are living and flow toward the site of the new tick attachment, attracted by the rising level of the tick saliva biofactors, as demonstrated through the pertinent research studies of Chien-Ming Shih, et al. This is the key chemically triggered behavior required to facilitate spirochete transfer to this new tick to be carried successfully to, yet a new host. Now this new tick becomes infected with Lyme Borrelia spirochetes, and the tick and spirochete duo are ready to reproduce, search for, and infect another mammal. [0036] These events are intimately and uniquely connected to and controlled by the make-up of tick saliva factors. The full range of the effects of the hundreds of chemicals in the saliva are still being determined, as it is extremely complex. The identification of the new mammal host, the adaptation to enter the host and survive the host's immune system, the accelerated proliferation of the spirochetes, the detection of a new tick on the host, and the transfer into the new tick are all connected and mediated by tick saliva factors. The pertinent prior studies firmly demonstrated this phenomenon with mice. [0037] The biggest problem for discovering a methodology of manipulation of this organism is that all Borrelia spirochetes are not stable in vitro (test tube), and only relatively so in vivo (living organisms). In other words, it has to be manipulated within the host in order to produce consistent results. [0038] The collection of these established scientific observations and researches have created a knowledge base. Each avenue of research is an individual phenomenon, each as an entity unto itself. Coordinating and selective association of these data, in conjunction with the creation and use of a unique application instrument and specific methodology creates a directed process for improved infection detection and treatment for Lyme disease. [0039] The observed natural phenomena of the tick/spirochete relationships of actions and reactions create a platform of controllable variables for manipulation. Manipulation of a natural response to create an action within an unusual and predictable timeframe is essential to detect these pathogens. [0040] Lyme spirochetes contain the largest number of genetic units of reproduction (DNA replications) of any bacteria known. They have no close relatives, genetically. The closest is the Treponema spirochete (syphilis) at 40% similar (which also can trigger a false positive with a Western Blot test). This makes active live Lyme disease very specific to detect with larger quantities of spirochetes in the blood, especially utilizing a PCR diagnostic test, if they can be drawn into the blood stream. [0041] Some of the difficulties in detecting the Lyme pathogen include the Lyme spirochete undergoing alterations in its physical form and encysting, waiting for a better time to re-activate (i.e. detection of a fresh new host). They can also rapidly change their chromosomal structure in response to environmental pressures. These organisms also change their genetic structure to adapt to the present host and their immune system. The spirochete populating adapts with differentiation from information from past infection hosts, creates a dormant or hidden infection, and the present infection can be virtually impossible to directly detect by testing blood. [0042] Therefore, what is needed is a way to manipulate Lyme Borrelia and co-infective pathogens in a controlled fashion to draw them into the blood stream, so that they are easily detected with extreme accuracy in an extraordinarily non-invasive and safe fashion. [0043] In addition, drawing the Lyme Borrelia into the blood stream increases the blood concentration of the spirochetes and the lower concentrations within dense tissues connected with the use of this procedure. It is suggested that they may also be more effectively treated in this phase as well. The infective agent's vulnerability at this time is the highest and will be more susceptible to traditional treatments. BRIEF DESCRIPTION OF THE FIGURES [0044] FIG. 1 provides an elevation view of an embodiment of an injection tine device. [0045] FIG. 2 provides an elevation view of another embodiment of an injection tine device. [0046] FIG. 3 provides a partial cut-away view of an embodiment of an injection tine device. [0047] FIG. 4 provides another partial cutaway view of an embodiment of the injection tine device. [0048] FIG. 5 provides a view of an embodiment of administration of the Borrelia provocation procedure. [0049] FIG. 6 provides a view of an embodiment of administration of the Borrelia provocation procedure. [0050] FIG. 7 provides a flow chart of an embodiment of a method of testing for Lyme Borrelia. [0051] FIG. 8 provides a flow chart of an embodiment of a method of treatment for Lyme Borrelia infection. SUMMARY [0052] The testing for the Lyme disease pathogen, ( Borrelia bergdorferi (Bb) and all Lyme Borrelia ), is notoriously difficult. The traditional methodologies of testing are extremely outdated given the established known behavior of the Lyme spirochete, specifically the behavior of developing mutations within itself in order to detect the identity of the carrier and avoid the immune system of that particular species by intentional mutational shift. Therefore it is counterintuitive to test immune reaction activity of the infected individual. To test for the bacteria itself should be the goal, but there has to be enough testable DNA material in the blood. Bb is not by nature a blood loving bacteria, and prefers the climate of avascular tissues such as cartilage. The Borrelia Provocation Procedure (BPP) kit protocol proposes to uniquely apply some previously known arts in combination with an original device of application. The BPP lures the spirochetes into the blood through a simple procedure of sub-dermal injection of benign tick saliva and co-factors. Lyme Borrelia can then be tested accurately 24 hours after the BPP, utilizing, for example, any Lyme Borrelia specific PCR (polymerase chain reaction) test for the most accurate results, as there will be abundantly available DNA present in the blood if there is an existing infection. Treatment is more effective at this particular time as well. [0053] The Borrelia Provocation Procedure kit (BPP) is a technology designed for the process accentuating Lyme disease testing and treatment effectiveness by luring Lyme Borrelia spirochetes out of dense avascular tissues and amplifying concentrations in the blood through utilizing bio-identical tick saliva factors and co-factors injected into the dermis. This is accomplished with a prepared, dose specific device within a prepared BPP kit designed specifically for this purpose. The procedure is followed up using any established appropriate testing for the pathogen itself. Utilizing the Borrelia Provocation Procedure (BPP) protocol will define infections accurately and definitively, making treatment timely and effective. Other co-infections may also become more detectable with the BPP and therefore become treated in a more timely fashion as well. In addition, this protocol will likely lead to more effective treatment procedures through creating a timing specific antibiotic bioavailability of the spirochete pathogen. Through the creative and unique combination and utilization of previously researched diverse prior arts and sciences, the use of a unique application device, and the proper timing as set in these parameters, a new methodology of Lyme disease detection accuracy is created. Lyme disease will become more controlled over time within the endemic environment of increasing infections, providing more effective and timely intervention. The BPP kit protocol makes accurate, non-invasive, active direct Lyme infection testing possible, and creates a platform for an effective treatment as well. [0054] The Borrelia Provocation Procedure protocol is based upon the intentional and artificial manipulation of a naturally occurring phenomenon to facilitate accurate Lyme Disease testing. It is accomplished through the application of a unique form of intradermal injection device controlling the dose and depth and dispersion rate of tick saliva factors as an activating agent, into the human dermis to purposefully stimulate the mobilization any Lyme Borrelia species directly into the blood providing a testable concentration platform of pathogens. The full procedure involves the process of injecting the tick saliva factors into the skin of the patient, waiting 24-48 hours for mobilization of the spirochetes into the blood, and providing appropriate testing, primarily utilizing any available species specific PCR (Polymerase Chain Reaction) detection test for any Lyme spirochete factor. The use of this procedure creates the most viable testing platform producing greater sensitivity, specificity and accuracy of Lyme testing. Problem Summary: [0000] a. Borrelia is difficult to test in human blood. Bb lives in the central nervous system, joints, and connective tissue. Lyme Borrelia spirochetes do not prefer to live in the blood stream, at least not in significant amounts, so these pathogens can easily be missed when testing only blood. b. Antibodies are not always produced by the carrier. Often the white blood cells are corrupted by the spirochete, and will therefore not create antibodies. Traditional Lyme disease screening depends on specific immune responses only. c. Testing tissues other than blood is more invasive to the patient, creating medical complications and unnecessary expense. d. False negatives and positives contribute to the problem of inappropriate or delayed treatment. 41-55% of tests result in false negatives. For example, only 10% of those with the defining erythema migrans rash will sero-test positive, though the rash itself confirms the diagnosis. Natural Metabolism of Borrelia Bergdorferi Summary: [0059] Once already established in the human body, the Lyme Borrelia spirochete will detect the presence of another host (tick) as being available to facilitate transfer through tick saliva triggers in the blood. e. The saliva of the tick acts on the host body to suppress pain response, increase blood flow to the area, modulates the host's immune system, and prevents clotting. As this is going on, the Bb in the cartilaginous tissues of the host mammal are signaled to move into the blood (not its preferred environment) in order to get to the new host tick. Thus the spirochete pathogen is drawn to the new tick host through the blood to enable the transfer. f. Spirochetes are released into the blood from dense avascular tissue, its natural habitat, in order to become ingested along with the human/mammal blood into the new tick host system to await transfer to new carrier. g. There are more than 400 proteins in the tick saliva of which only some functions are known. These combined factors appear to make this transfer more probable. This also makes utilization of a single saliva protein factor to stimulate migration very unlikely, so all factors of tick saliva should be theoretically used. Theory: [0063] If, for example, “tick saliva” is artificially introduced into the system, for a short period of time one of three things will happen: [0000] 1) The actual spirochete moves into the blood and is 100% detectable A. Perform a Borrelia specific PCR type test using a digital PCR machine detection system, already established and in standard use B. Testing and accurate diagnosis is complete within 24-48 hours 2) Antibodies may be triggered if the body can recognize the mobile Bb organism (one week to ten days) A. Perform an ELISA test B. Secondarily, perform a Western Blot test 3) There is no spirochete Bb or other related pathogen present, and therefore any testing for actual pathogen (PCR) will be negative. Process in Brief: [0068] A kit contains either a tine injection (the BPP as described) or alternately an intra-dermal injection. These are utilized to mimic the introduction of a small amount of tick saliva and keratin into the skin, and to the capillary blood. The Bb pathogen will be on the “blood radar” within 24-48 hours after this provocation. Solution #1: [0069] Being testable very soon after a bite will speed the appropriate use of antibiotics, which are 70-90% effective if treated early. If not treated, the treatment effectiveness rapidly drops to 60% with a 35% relapse rate. The longer the Lyme Borrelia remains untreated, the more difficult it can be to eradicate. Solution #2: [0070] Knowing that there is an active Lyme spirochete in the system is critical to dictating appropriate treatment, as compared to the situation of antibodies being detected but there is no longer a pathogen present. Likewise, not knowing a cloaked pathogen is there and missing treatment. DETAILED DESCRIPTION [0071] The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention and does not represent the only forms in which the present invention may be constructed and/or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. [0000] 1. As used herein the term Bb, Borrelia bergdorferi , all refer to the entire class of infective agents inclusive and called Lyme Borrelia interchangeably. This includes, but is not limited to, Borrelia burgdorferi, Borrelia garinii, Borrelia afzelii, Borrelia bissettii, Borrelia hermsii, Borrelia japonica, Borrelia lonestari, Borrelia lusitani, Borrelia spielmani, Borrelia tankii, Borrelia turdae, Borrelia turicatae , and Borrelia valaisiana strains. 2. As used herein the term BPP refers to the Borrelia Provocation Procedure, in any method utilized. 3. As used herein the term SGE refers to the active ingredients of tick salivary gland extracts, whether natural or artificially created, or modified. 4. As used herein the term PCR refers to the long established Polymerase Chain Reaction procedures. It is specified as to whether it refers to the pertinent prior arts of detection or manufacture of these chemical chains. Borrelia Provocation Procedure Kit Contents: [0000] 1) Tick saliva-production/manufacture (standard field procedure example): a. Ramification 1: A selection of Lyme (−) and pathogen (−) ticks are sourced. (For example, the University of Neuchatel maintains a tick colony for such situations.) The following SGE (salivary gland extraction) procedure is an example of the process of natural source extraction of product. i. Tick salivary gland extract (SGE) procedure example: 1. Lab procedure a. Glue ticks to bottom of petri dish and place on ice for 20 minutes b. Incise along the dorso-lateral margin and remove the dorsal integument c. Isolate and transfer into 0.1 M phosphate buffer solution (PBS) containing a protease inhibitor cocktail (Sigma, P2714), ph 6.0 and kept at −20° C. d. Homogenize and centrifuge at 1000 rpm. e. Elution is performed with the same buffer, collecting fractions of 3.0 ml while the absorbance is monitored at 280 nm. 2. Alternate lab procedures for glandular extraction will work as well. This is a common procedure for research, and this is only one variant of the procedure. b. Ramification 2: A reasonable synthetic of the functional tick saliva is produced utilizing technologies such as the SMART™ PCR cDNA synthesis kit (Clontech, Palo Alto, Calif.) for mass replication. Recent advances in insect cell expression systems can now produce fairly substantial quantity of these recombinant proteins. c. Ramification 3: As in ramification #2 with identifying and eliminating the anti-coagulating factors (as defined by Godfroid), in order to produce an otherwise bio-identical SGE, but reduce the risk of bleeding for those on blood thinning pharmaceuticals, or those with clotting issues. d. There may be issues that require refining for maximum accuracy of the final test regarding the mobilization rate of the Borrelia with natural SGE (salivary gland extract) vs. synthetic PCR cDNA (manufactured tick saliva). This has not been researched as of yet, though the closest comparison example is that it is observed that there is a 10-20 fold increase in spirochete migration toward the SGE compared to PBS (Phosphate buffered solution) alone. There is no research or established art comparing the rate of migration of Lyme Borrelia towards natural SGE and PCR cDNA tick saliva proteins. 2) Injection: A bolus containing a small amount of tick saliva factors (45 micro grams) is injected into the dermis with a single dermal needle or by piercing the dermis with injecting tines. In one embodiment, the injection site will be at the location of the back of the same upper arm which will be phlebotomized later. The injection tines device is a significant and unique modification of the original, but no longer utilized, tuberculin tine type test for tuberculosis, and is shown in the figures herein. a. Most protein bands should be used to mimic the actual tick bite. i. Immunoregulatory peptides include—hyalomin-A and hyalomin-B (identified from the salivary gland of the hard tick Hyalomma asiaticum asiaticum ): Anti-haemostatic factors: Anti-Inflammatory factors: Anti-Serotonin factors (binding histamine and serotonin): and bradykinin modulators. ii. Include the pharmacologically active components of the tick salivary proteins (Valenzuela). Salp15 protein is not a required factor, as it only mediates the spirochete cloaking. iii. The haemostatic factors could be included in the final use product to dilate and move the salivary factor through the circulatory system in order to trigger a response. Cautionary measures should be taken to monitor patients in order to prevent localized bleeding or events with pharmacological blood thinners [instructions and warnings to be included in printed material instruction insert]. During trials, this factor may be included or removed to reduce patient negative reaction events. b. The use of a cDNA library will come into play, using PCR subtraction and the construction of a full-length cDNA library resource from tick saliva using functional genomics to aid this process. The construction of SGE via PCR technology allows for the modifications in the protein structures outlined above in section (a). Mass production can be accomplished in this fashion, removing only some of the immune modulating factors. c. Ramification (B) variant: The injection tine device has needle injection depths chosen specifically to imitate the depth of the hypostome of the feeding tick in different phases; specifically—0.14 mm, 1 mm, 1.25 mm, and 2.75 mm. A 3.25 mm should be included for the larger variants of ticks worldwide, particularly associated with Asian species. This variation of staggered tine depths will mimic the slow introduction of saliva into the host via the hypostome. d. Ramification (A & B) variant: A keratin matrix would slow the introduction of these factors into the blood, mimicking the slow introduction by the ticks themselves, of greater importance, and quantity requirements if single needle injection method is used. Ticks produce a keratin substance in association with their bites, so will not interfere with the SGE attractant qualities. 3) Waiting Period: The time of injection to the time of serum withdrawal is ideally within a 24-48 hour period. The ideal period for highest spirochete migration seems to be 48 hours, in vitro. (This information is to be included in the BPP kit as detailed laboratory site instructions and a patient handout). There is a decreasing concentration over the next 8 days, making the test progressively less sensitive past 48 hours, but still somewhat effective from day 2-5. The blood draw should ideally be in the same extremity as the BPP for the highest concentrations. In one embodiment, the blood draw may take place within approximately six inches from the BPP injection site. The use of a standard blood draw maintains the CDC accepted guidelines, reduces the cost, reduces adverse events, and increases the availability of accurate testing. 4) Testing: The standard PCR (polymerase chain reaction) test can be most effectively used in this case to detect Lyme Borrelia DNA. Any Borrelia specific PCR test will perform with more accuracy within this methodology than previously demonstrated with serum PCR testing in past attempts. With the PCR test, the process is to detect the Borrelia DNA directly, where there is no dependence on the unpredictable immune responses of the patient, as with the ELISA test. However, it should be understood that other tests capable of detecting a presence of Lyme Borrelia in blood may be used without straying from the scope of this invention. a. Ramification variation-Testing-: The FISH (fluorescent In-Situ Hybridization) test for Babesia (a co-infection) can be utilized if desired at that time. This is a standardized test based on direct microscopy for RNA of the Babesia . Appropriate treatment can be applied as a result. b. Ramification variation-Testing-: Using the BPP to stimulate other co-infections and tick born infective agents to mobilize into the blood. Any other specific diagnostic procedure could be run at this time c. Ramification variation: A unique variation of use is a non-shellfish keratin based carrier agent. This would significantly slow the dispersion rate of the protein factors if injected with the saliva bolus. If the dispersion of the saliva is too rapid, it is possible it may not trigger the spirochete's natural attraction pattern. Keratin additions would slow the rate of saliva dispersion without significant side effects. Any useable keratinocyte cell culture procedure may be used. 5) Treatment Ramification: Use of the BPP kit protocol mobilizes the pathogen out of avascular, dense tissues and into the circulatory system. The peak appropriate start of antibiotic treatment should occur at 24-36 hours, post Borrelia Provocation Procedure. At this point, through the BPP utilization, the bulk of the pathogen population is temporarily available and vulnerable. Initiating treatment by manipulating the infective agents into the blood establishes a very accessible treatment location for antibiotic therapy. In this paradigm, the standard antibiotic treatments effectiveness ratings will improve. This is a unique pre-treatment modality possibility, and no references have been located on this possible avenue to provide treatment upon artificial manipulation. Embodiments of Invention [0000] A. Embodiments may be used to enhance the detection of Lyme disease in humans at any stage of the infection. B. Embodiments may be used to enhance the detection of Lyme disease in animals. This is an open field requiring testing improvements, utilizing the same processes as described for the human model. C. Embodiments may be used in the treatment of Lyme disease and its co-infections. Through the use of the BPP to move more of the spirochete pathogen into the blood and surface tissues, as it makes the pathogen more bio-available for easy eradication through antibiotic use. D. The present invention is described by reference to an example. The use of this and other examples anywhere in the specification is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified form. Likewise, the invention is not limited to any particular preferred embodiments described herein. Indeed, modifications and variations of the invention may be apparent to those skilled in the art upon reading this specification, and can be made without departing from its spirit and scope. The invention is therefore to be limited only by the terms of the claims, along with the full scope of equivalents to which the claims are entitled. Advantages of Invention [0103] 1) As a detection modality, the BPP kit protocol modality has the potential to be one of the least expensive, least invasive, and most accurate testing adjuncts available for improving available Lyme disease testing. The need for more effective technology is most assuredly present as Lyme disease is presently the 6 th fastest growing disease in this country, and a growing concern worldwide. (Recent CDC estimates have increased this ranking due to a 10× underestimation of infections. Actual relative ranking reflecting this information is not available at this time.) 2) The present accepted and most effective method of testing for the actual live presence of the Borrelia pathogen is the class of PCR test procedures, which vary according to manufacturer. Other traditional tests only evaluate the immune response (This is a problem because the individual may have been infected previously, recovered, was treated, or had no immune response). PCR tests are now only traditionally utilized through the invasive collection of synovial fluid, cerebral spinal fluid, optic fluids, and tissue biopsy due to the higher concentrations of the Lyme Borrelia species in these tissues. To simplify general population testing, simple blood serum collection after the BPP protocol will enhance and expand the use of accurate PCR serum testing significantly. Also for screen testing, only blood is the acceptable source for testing according to the FDA/CDC guidelines. Utilizing the BPP previous to serum testing does not eliminate creative opportunity within this scope of Lyme Disease testing, but demands more labs create further mechanical testing options, opening up more opportunity for patent definitions of testable DNA and polymerases within the species. 3) CDC diagnostic procedures will, by necessity, require updating. The revelation of the discovery of the underreporting of this infection is making this eventuality more apparent as a result. The NIH is supporting the development of new PCR type testing, but this pre-testing BPP kit will improve the outcome of any of the PCR mediated tests, causing no patent conflicts nor NIH issues for any of the developers within this growing field of research, and improves the accuracy of all the outcomes. These technologies require inventive acceleration in development, but this fact does not apply to this specific group of claims. 4) The FDA does not approve of diagnosis based upon the testing of urine or other body fluids to define an infection from Bb. Blood serum testing is the only acceptable tissue to be used for diagnosis at this time. Blood testing also simplifies testing procedures and makes it easily available to physicians and labs, while it stays within FDA guidelines. 5) The public has lost confidence. The state legislative levels of regulation regarding the accuracy of Lyme disease testing are on the increase as well. More states are requiring Lyme test “inaccuracy disclosure statements” for patients to be provided with from the testing agents. The level of public savvy, and fear regarding this subject is escalating beyond present technology expectations, and the industry has to keep up with the demand for more. Not only are peer reviewed science periodicals recognizing the need for awareness, prevention and early detection and treatment, but it is being discussed in popular literature. For example, one study estimates a 55% testing failure rate in early stage patients. A change from an outdated mode of testing to a more accurate and reliable testing methodology to include what is already available would resolve the public demand for disease control and resolution in a timely manner. 6) As previously indicated, the BPP protocol can possibly assist in the detection of the Babesia co-infection through the FISH testing protocol. There are other co-infections that are involved with Lyme disease, and they are detected through laboratory testing as well. Most pathogens are not quite as difficult to test as the Bb spirochete, but this protocol has the potential to be used for the increased accuracy in the detection of Ehrlichia as well. 7) This protocol is not just for human testing, but also applies well to veterinary testing, as many canines, felines and equines possess the antibodies of past infections that have been treated, but they may or may not have been re-infected. 8) An unanticipated but likely conclusion is that the BPP may be used in conjunction with traditional antibiotic therapy as a pretreatment to bring the pathogen into reachable, blood filled tissues where the antibiotics can easily affect effective eradication. [0104] The use of the Borrelia Provocation Procedure in conjunction with already existing testing technologies will significantly change the diagnostic accuracy, timeliness, and therefore treatment effectiveness. The potential also lies within the BPP to also improve the effectiveness of traditional treatment protocols, at any stage of the infection, due to the BPP outcome expectations. [0105] Travel in the blood for Lyme Borrelia spirochetes is exceedingly slow compared to the movement in collagenous tissues in which they usually prefer to live. Unless lured into the blood, it can be virtually undetectable in blood as a pathogen, especially compared with many other bacterial infections. In addition, they actually adjust their DNA and chromosomes to adapt to the new individual's immune system, and as a result they do not readily set off the host's immune system alarms, remaining virtually invisible to the immune system. If the immunoglobulins themselves have been infected, pathogenic detection of immune response is impossible. Therefore, Bb requires a different detection method. The solution to this testing dilemma is to deliberately lure the spirochetes into the blood, within a specific time frame. This is accomplished by using the BPP protocol prior to blood testing. The testing is no longer immune system (ELISA) dependent, and therefore this makes tests for the actual detection for the presence of Bb, such as a PCR tests, quite sensitive and responsive. [0106] Presently, PCR testing tends to be utilized in association with invasive and expensive biopsies of tissues and fluids collected from where the pathogen gathers in its greatest numbers, such as joints, heart, and nervous tissues, etc. It is generally not used for Bb detection in blood due to the low concentration of the pathogen there. Once the Lyme Borrelia is in the blood through the use of the BPP protocol, the PCR is the best present universally accepted choice. [0107] By creating a controlled system of environmental variables as with the BPP, the pathogen becomes controlled, uncloaked, un-encysted, detectable, and therefore treatable in blood within a predictable time frame. [0108] Turning now to FIGS. 1-4 , views of an embodiment of the injection tine device are provided. The injection tine device 20 comprises a base 12 which provides a body for the structure of the device. A balloon reservoir 16 on the base 12 is in communication with a plurality of needles 19 . The needles 19 allow fluid 17 within the reservoir 16 to be ejected through them. At a bottom 11 of the device, an injection platform 18 is movable with respect to the needles 19 from a covering position that covers the needles 19 , to a retracted position that exposes the needles 19 . In operation, the platform 18 may be positioned against a skin of a user, and the needles 19 urged into the skin, causing the platform 18 to retract. At top plunger 13 has a spring 14 between it and the injection platform 18 . The plunger 13 allows force to be applied to the device 20 . As the plunger 13 is depressed against the spring 14 force, the reservoir 16 is compressed, urging fluid therein out of the needles 19 . Similarly, upon the depression of the plunger 13 , the needles 19 are urged out of the platform 18 and, if the platform 18 is on a soft surface such as a subject's skin, the needles will continue to pierce the skin, while the platform 18 moves to its retracted position while stabilizing the device 20 . In some embodiments, the injection tine device 20 may have a safety bracket 15 that requires the plunger 13 to be twisted to break the bracket 15 and allow the plunger 13 to depress. The needles 19 may be of any size to allow the salivary gland extract to be injected into a test subject. In one embodiment, the needles are sized to mimic the injection depths of an actual tick bite. As such, the needles 19 in this embodiment may have lengths of 0.14 mm, 1 mm, 1.25 mm, 2.75 mm, 3.25 mm, and/or any combination thereof. [0109] In a particular embodiment, small gauge (30) dermal needles of varying lengths for multiple depth injection levels in the dermis may be used. The balloon reservoir holds a saline flush to mobilize the SGE and Keratin matrix out of the inner reservoir into the needles and into the tissues. The reservoir is protected by a safety tab bracket, which is broken just prior to injection. The injection is mediated by a spring coil tension release device in the core. [0110] The device comes to the lab in a single unit with a bottom cover of dense core foam designed to cushion the injection needles. It is untwisted, the top and bottom covers removed, and the device is ready for immediate use. [0111] FIGS. 5 and 6 provide views of an embodiment of the injection process. The injection tine device 20 is prepared for injection of the salivary gland extract into the test subject 21 by an administrator 22 . Once prepared, the device is placed on a skin of the test subject 21 and the needles inserted, allowing injection of the fluid through the needles. [0112] In one embodiment, the placement of the BPP tine or bolus may be in the same extremity as testing will be, in order to improve testing, due to higher concentrations of spirochete numbers at the provocation site if an infection is present. The posterior of the upper arm is ideal. [0113] In another embodiment, the administrator may place the recessed needle injection platform pad on the arm, gently but firmly, and then trigger the top plunger to release the spring for a single use, disposable injection of SGE as a Borrelia Provocation Procedure. [0114] FIG. 7 provides a flow chart showing steps of an embodiment of testing. The method begins with the obtaining the salivary gland extract (SGE). As discussed above, the SGE may be either natural or synthetic. The obtaining step may apply to either creating, purifying or otherwise extracting or generating the SGE, or may simply refer to loading a syringe or injection device with pre-prepared SGE. The obtained SGE may then be injected into a patient/test subject. This may be a human, or other mammal, depending on application. Once injected, there is a waiting period to provoke the Lyme Borrelia to leave its preferred tissue and enter the blood stream of the patient. After this waiting period, blood may be drawn and tested for the presence of the Lyme Borrelia . A presence of it indicates that an infection is present, while a lack of it indicates that there is likely no infection. [0115] FIG. 8 provides a flow chart showing steps of an embodiment of treatment. The method begins with obtaining the salivary gland extract (SGE). As discussed above, the SGE may be either natural or synthetic. The obtaining step may apply to either creating, purifying or otherwise extracting or generating the SGE, or may simply refer to loading a syringe or injection device with pre-prepared SGE. The obtained SGE may then be injected into a patient/test subject. This may be a human, or other mammal, depending on application. Once injected, there is a waiting period to provoke the Lyme Borrelia to leave its preferred tissue and enter the blood stream of the patient. Once the Lyme Borrelia is exposed in the blood after this waiting period, it is susceptible to treatment by traditional antibiotics which also are carried through the body through blood. In some embodiments, treatment may be repeated to ensure complete eradication of the Lyme Borrelia. [0116] BPP may be applied to routine blood testing for Lyme disease is unique as it has not been performed on humans, nor used as a diagnostic platform in and of itself. Blood is the easiest to access tissue for testing. There is no harm as tick saliva activity is short lived and even if artificially produced, it will still dissipate in an uninfected individual. Within an infected person, it cannot aggravate the condition as they already carry the agent of infection. [0117] Despite utilization of portions of several prior arts: 1) saliva injection, 2) production of saliva or extraction of saliva, 3) production of keratin-like substances, and the use of 4) PCR testing, the specific and measured tine applicator and the unique combination of this entire procedure combined has not been utilized for defining an active Lyme disease infection or treating Lyme disease in humans. [0118] The utilization of this kind of protocol for the treatment of human and animal active Lyme disease infection is completely without prior art. The methodology opening to this possibility of treatment was inferred by prior immunological studies. The studies state, in essence, that 4-6 days after injection of tick saliva into mice, the spirochete concentration in dense tissues (heart) decreased and in dermal surface tissues the concentration increased. This patent postulates that manipulating this natural reaction creates antibiotic bioavailability of the spirochete pathogens within humans. The issues of possible diagnosis and treatment has never been discussed in these researches, only the immune responses and modulations from this team's studies. Prior Arts Concepts Referenced and Unified Novel Applications [0119] Tick saliva extracts have been studied and are a standard substance of procurement for research facilities for almost two decades, and is only a tool in this Borrelia Provocation Procedure protocol. Only one methodology is discussed in detail here, but there are many avenues of natural harvesting as well as artificial production (PCR), as suggested. [0120] The production and use of keratin-like substances are also a standard in laboratory procedures. There are many variants, and only one specific form has been discussed in this document. [0121] The chemotaxic migration and observed manipulation of the Borrelia spirochete was a research topic of Chen-Ming Shih and others at the Department of Parasitology and Tropical Medicine in Taipei, China. The focus of this institute and its researchers is simply the defining and identification of a relatively new invasion of the disease to Taiwan. The behavior of the spirochete is the focus of their studies, and no mention of human testing, treatment nor are vaccines discussed here. The primary weakness of their research, which had to be compensated for within the scope of this patent, is that their research is in vitro, which substantially alters normal behavior of these sensitive spirochetes. The key of their research which applies to this patent is that the association of the saliva factors mediates transmission of the Borrelia spirochete, but the mechanism responsible is not yet defined. As a result the use of bio-identical tick saliva, natural or PCR created, is required (one can assume) in its entirety to mediate the provocation response the BPP triggers. It is a key point here, but not the focus of these researchers or this institution. [0122] The use of a PCR technology is almost an expected technology in modern science, particularly concerning detection and immunology today. The accuracy and application of the PCR (polymerase chain reaction) allows DNA to be cloned, either amplifying and/or targeting nucleic acid sequences. It is now the standard tool of the diagnostic and manufacturing medical and chemical science industries, including the detection devices for the Borrelia spirochete detection. Its use for this patent does not alter this patent, nor is the patent dependent upon it. It is the best of the detection tools to apply after the BPP is utilized. [0123] Because of its versatility, it is also the most affordable and prolific methodology of manufacturing tick saliva factors. Its use is as an economic tool for production and detection accuracy, preserving energy, resources, and expense. [0124] This combination of the prior arts is not obvious, as each factor of research is targeting their specific subjects in different unrelated areas of science arts—behavioral entomology and human immunology. The combinations presented in this patent cannot be inferred through the present directional paths of each of the research avenues and studies or the individuals or organizations behind them. There seems to be no direct route to the conclusions of testing and treatment for humans from the sources of the parts of this co-related information, as presented for the Borrelia Provocation Procedure. [0125] In summary, and as can be seen from the prior discussion, there is a potential for the use of the PCR, or polymerase chain reaction, testing using the spirochete DNA itself, but because of traditionally low numbers of spirochetes in the blood, this test has not been reliable. [0126] The least invasive and most economical manner of Lyme testing is using blood. Existing PCR testing had been proven to be quite effective in identifying Bb and all other strains of Lyme Borrelia , previously from specimens obtained from other deep tissues that have been biopsied (an invasive and expensive procedure), but not blood due to low concentrations. Utilizing the Lyme Borrelia provocation procedures discussed herein, with PCR detection methods, as an effective and accurate testing method can be simply utilized with blood as the source. The same is true for traditional testing of co-infective agents. [0127] Lyme Borrelia live in the central nervous system, joints, and connective tissue. They do not typically live in the blood stream, at least not in significant amounts, so it can easily be missed when examining and testing blood. So if a lab finds them in the blood without a BPP in small amounts it generally is an indicator that there is a high amount in other tissues in the body. With the co-infections, the detection rates are also sporadic and difficult to detect without specific testing indicated from symptoms. The BPP kit testing protocol may increase the concentrations of the co-infection into the blood by its own co-infective nature of re-infection, possibly improving their rates of detection as well. [0128] With the utilization of the BPP Tine or Bolus stimulus, the artificial stimulation of the natural reaction of the pathogen is to release the spirochetes into the blood from avascular tissues, therefore facilitating accurate, specific, and sensitive testing, creating a new gold standard for Lyme detection. If the Borrelia and co-infective pathogens are manipulated in a controlled fashion into the blood stream, they are easily detected with extreme accuracy in an extraordinarily non-invasive and safe fashion, solving most of the Lyme Disease Laboratory Testing problems and utilizing presently available technologies to do so. [0129] While several variations of the present invention have been illustrated by way of example in preferred or particular embodiments, it is apparent that further embodiments could be developed within the spirit and scope of the present invention, or the inventive concept thereof. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention, and are inclusive, but not limited to the following appended claims as set forth.
The testing for the Lyme disease pathogen, ( Borrelia bergdorferi (Bb) and all other Lyme Borrelia ), is notoriously difficult. Bb is not by nature a blood loving bacteria, and prefers the climate of avascular tissues such as cartilage. The Borrelia Provocation technology disclosed herein proposes to uniquely lure the Lyme Borrelia spirochetes into the blood through a simple procedure of sub-dermal injection of benign tick saliva and co-factors. Lyme Borrelia can then be tested accurately after the provocation injection, utilizing any Lyme Borrelia detection test such as a specific PCR (polymerase chain reaction) test for the most accurate results, as there will be abundantly available DNA present in the blood if there is an existing infection. Treatment is more effective after provocation as well. The provocation protocol taught herein makes accurate, non-invasive, active direct Lyme infection testing possible, and creates a platform for an effective treatment as well.
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BACKGROUND OF INVENTION 1. Field of Invention The present invention is directed to the arts of recycling old corrugated container (OCC), more particularly to a process for the making of recycled linerboard or Kraft paper from OCC having strength properties comparable to those made using virgin unbleached Kraft pulp (UKP). Such recycled linerboard or Kraft paper finds particular application in the inexpensive substitutes for linerboard or Kraft paper made using expensive virgin UKP. The conventional arts of recycling OCC employ the method of fiber fractionation to separate long fibers (UKP) from OCC furnish. But due to inherent inefficiency of screen-fractionators being used, recovery of UKP content to the level required for high quality linerboard or Kraft paper has not been possible and, therefore, a large amount of virgin UKP had to be added in order to obtain strength properties demanded in the market. This forced to waste valuable UKP in OCC and consume virgin UKP made from natural timber resources. Thus it would be beneficial to replace virgin UKP by recovered UKP from OCC and eliminate completely the need for using virgin UKP for the making of recycled linerboard or Kraft paper. 2. Description of Prior Arts A typical stock preparation process for recycled linerboard or Kraft paper using OCC is roughly described by the FIG. 1. A high consistency furnish (4˜8%) is formed at the pulper where OCC is defibered by water. Heavy contaminants in OCC furnish are eliminated by high-density cleaners and large size but relatively light contaminants are eliminated by coarse screens. In addition to cleaning and screening, high-density cleaners and coarse screens perform defibering of remaining OCC fractions. The corrugating medium glued between the two facings of linerboards is composed mainly of semichemical hard wood pulps having fiber length shorter than 2 millimeters. Although unbleached Kraft pulps (UKP) having fiber length longer than 3 millimeters occupies over 80% of linerboard, the UKP content in OCC furnish is reduced to approximately 55% because of the low quality fibers in corrugated medium that takes about one third of the OCC weight. More water is added to the OCC furnish to make the consistency of the furnish below 1% and sent to fine screens to eliminate small size contaminants from OCC furnish as rejects. Then accepts from fine screens are sent to fractionators to divide OCC furnish into two separate streams, long fibers and short fibers. Long fiber stream goes through lightweight cleaners and forward cleaners where lightweight contaminants are eliminated. And at the disk thickener water is removed to make the consistency high enough to be refined by dispersion refiner. Then the remaining contaminants such as wax are further dispersed into small particles by heating tubes and sent to paper machine wire. The increase in UKP content in the long fiber stream achieved by fractionators is not sufficient to meet with strength requirement of recycled linerboard or Kraft paper. This forces the addition of virgin UKP to the long fiber stream. The short fiber stream from fractionators are further cleaned by lightweight cleaner and water is removed by disk thickener before being sent to paper machine that makes corrugating medium. Normally, low quality recycled fiber is further added to the short fiber stream before it is sent to a paper machine that makes corrugating medium. In the arts of OCC recycling described above, deterioration in strength properties of linerboard or Kraft paper made from fractionated OCC furnish has been taken as unavoidable. Therefore, manufacturing of recycled linerboard or Kraft paper required addition of a large amount of virgin UKP to achieve the level of strength properties demanded in the market. SUMMARY OF THE INVENTION In one embodiment, the invention is directed to a stock preparation process for the making of recycled linerboard or Kraft paper, wherein a furnish is prepared by pulping OCC, high-density cleaning, coarse screening, fine screening, fractionating, lightweight cleaning, forward cleaning, disk thickening, dispersion refining, dispersing wax into small particles, and adding virgin UKP, characterized in: Separating linerboard from corrugated medium before pulping. In another embodiment, the invention is directed to a stock preparation process for the making of recycled linerboard or Kraft paper, separating linerboard is achieved by shredding and cutting OCC into pieces and then by float-separating linerboard pieces in water. In still further embodiment, the invention is directed to a stock preparation process for the making of recycled linerboard or Kraft paper, wherein separating linerboard is achieved by crushing OCC into pieces by agitating OCC in water. In still further embodiment, the invention is directed to a stock preparation process for the making of recycled linerboard or Kraft paper, wherein separating linerboard is achieved by an auxiliary pump and/or gate valve installed between a pulper and a short fiber chest. In still further embodiment, the invention is directed to a stock preparation process for the making of recycled linerboard or Kraft paper, wherein elimination of micro-fibrils from recycled furnish is achieved by disk thickener and/or fractionators. In still another embodiment, the invention is directed to a stock preparation process for recycled linerboard or Kraft paper, wherein recovery of long fibers from reject streams of fine screens is achieved by non-refining disperser. A further embodiment discloses a process of stock preparation for recycled linerboard or Kraft paper characterized in the following steps: (a) Cutting and/or Crushing OCC into pieces, (b) Separating linerboard pieces from corrugated medium pieces before pulping linerboard pieces, (c) Removing corrugated medium pieces remaining in linerboard pieces by pulping corrugated medium pieces first and then by sending defibered corrugated medium to short fiber chest by actuating auxiliary pump and/or gate valve. (d) Adding effective amounts of NaOH to the variable speed pulper immediately after removing corrugated medium. (e) Eliminating micro-fibrils from linerboard or Kraft paper furnish by disk thickener and/or fractionators, (f) Minimizing long fiber loss by recovering long fibers from reject streams of fine screens by non-refining disperser, (g) Applying dry strength additives to linerboard or Kraft paper furnish. (h) Maintaining a pH of furnish at the head box of paper machine at least 5.5 and at highest 6.5. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic description of conventional stock preparation process for recycled linerboard and corrugated medium that use OCC that adds virgin UKP to meet strength requirements of linerboard. FIG. 2 is a schematic description of this invention that reproduces new corrugated container board from OCC without adding virgin UKP. DETAILED DESCRIPTION OF THE INVENTION The objective of this invention is to introduce effective means to recover UKP from OCC and apply it to achieve the level of strength properties of recycled linerboard or Kraft paper demanded in the market without adding virgin UKP. The table below explains the compositions of corrugated container made in the US in 1998. Year 1998 1000 tons % in weight Corrugated Container 30,280 100.0 Linerboard 20,911 69.1 100.0 Virgin UKP 16,903 55.9 80.8 Solid Bleached 149 0.5 0.7 Recycled 3,859 12.7 18.5 Corrugating Medium 9,369 30.9 100.0 Semi-chemical HWP 5,665 18.7 60.5 Recycled 3,704 12.2 39.5 Based on Data Published by American Forest & Paper Association While the virgin UKP content of linerboard is 80%, the corrugating medium has virtually no UKP and instead it is made of semi-chemical hard wood pulp (HWP) and low quality recycled fiber. As the strength of paper (linerboard or Kraft paper) depends primarily on the average length of the fibers that constitute it, maintaining the UKP content in a paper is the prerequisite to achieve acceptable paper strength. From above table, we see that UKP content decreases to 55.9% in OCC even though it is as high as 80% in linerboard. Once the linerboard is separated from OCC before pulping OCC, the remaining OCC furnish will have higher UKP content close to 80%. Hence, the separation of linerboard from OCC before pulping is a must in order to achieve the strength properties of recycled linerboard or Kraft paper without adding any virgin UKP. There are other causes that contribute to the deterioration of strength properties of recycled linerboard or Kraft paper. One of the causes is the loss of fiber strength due to hornification of hydrogen bonded fibrils. A large portion of hornified fibrils turn into micro-fibrils in the process of re-pulping when they are stressed during the process of defibering and cleaning. When they remain in furnish, they tend to interfere with new hydrogen bonds to be made between recycled fibers resulting in the reduction of relative bonded area (RBA) between fibers and consequently reducing tensile strength of recycled paper. Another factor involves the loss of long fibers through the reject streams of fine screens, which results in the further decrease of UKP content in furnish. Therefore, in order to achieve the adequate level of UKP content in recycled linerboard or Kraft paper without adding any virgin UKP, two techniques must be employed in addition to separating linerboard from OCC before pulping. They are elimination of micro-fibrils from furnish and minimization of lost long fibers. As corrugated medium made from semi-chemical HWP and low grade recycled fibers is glued between the two faces of linerboards using starch, addition of water resolves the starch loosening corrugated medium pieces from linerboard pieces. To achieve high efficiency of linerboard separation from OCC, a process of shredding and cutting OCC is required. However, in the case of using already cut corrugated container boards such as new DLK corrugated cuttings, the process of shredding and cutting is not necessary. With slight agitation of water soaked OCC pieces, corrugated medium pieces loosens themselves from linerboard pieces. When enough amount of water is added further, linerboard pieces having lighter specific gravity than soaked corrugated medium pieces float in the water, making the separation of linerboard pieces from corrugated medium pieces an easy task. In the next step, separated linerboard pieces are sent to the variable speed pulper having primary and auxiliary pumps or gate valve to short fiber chest. At the beginning stage of pulping, slow speed agitation of linerboard pieces mixed with corrugated medium pieces by the impeller of the pulper defibers corrugated medium pieces first before linerboard pieces are defibered. Then auxiliary pump and/or gate valve to short fiber chest is activated to send defibered corrugated medium pieces to short fiber chest. After defibered corrugated medium pieces are removed by low speed pulping and activating the auxiliary pump or gate valve to short fiber chest, an adequate amount of NaOH is added to the linerboard pieces remaining in the variable speed pulper. Then the second stage pulping operation is conducted with much higher impeller speed, which is required to defiber linerboard pieces, some of which are heavily wet strengthened. Normally quite a large amount of long fibers are lost through reject streams of fine screens. This is undesirable because it reduces long fiber (UKP) content in furnish and at the same time increases the amount of sludge, resulting in the deterioration of strength properties of linerboard or Kraft paper. To recover long fibers in the reject streams of fine screens, an additional process of defibering of hornified and/or wet strengthened linerboard fractions remaining in the reject streams is required. A non-refining disperser that does the job of defibering linerboard fractions and separating those fibers attached to contaminants improves strength properties of recycled linerboard or Kraft paper. A process of micro-fibrils elimination by means either of fractionators having small holes than normal or disk thickener having larger holes than normal is necessary to improve strength properties of recycled linerboard or Kraft paper. EXAMPLES The first example is the case of using recovered UKP from OCC for recycled Kraft paper manufacturing. After linerboard pieces are separated from 1 ton of OCC, about the half a ton of old sack Kraft paper is added together with 15 Kg of NaOH just before the second stage pulping. The test results are compared against Korean standards in the following table. Tests TBS (Kgf) TBS 5 Stretch Rate Tear Items BW (g/m 2 ) MD CD MD CD MD CD Sizing KS 80 6.8 3.5 15.0 16.8 95 108 15 and up A 79.8 8.1 3.9 15.9 16.8 99 104 16 B 79.6 8.1 3.9 15.3 17.2 96 114 17 C 80.2 5.7 3.1 14.5 15.6 88 96 15 KS: Korean Standard BW: Basis Weight TBS: Tensile Breaking Strength A. The first sample taken from Kraft paper made by the process specified in this invention. B. The second sample taken from Kraft paper made by the process specified in this invention. C. The sample taken from Kraft paper in which corrugated medium is not removed as the case with conventional method. It can be seen from above test results that separation of linerboard by the method specified by this invention made it possible to achieve the level of tensile breaking strength and stretch specified by Korean standard. This has been possible only by adding virgin UKP to OCC furnish. This implies the fact that UKP in OCC is effectively recovered and utilized for the enhancement of strength properties of recycled Kraft paper. In another example, this invention is applied to 21.7 tons of OCC. Since average UKP content of US made OCC is 55% (1998 data published by American Forest and Paper Association), at least 55% of OCC must be recovered and turned into Kraft paper by this invention. The recycled Kraft paper, made from the OCC by applying this invention without adding any old Kraft paper sack, weighed 12.01 tons (55.35% of OCC). The tensile breaking strength of the Kraft paper was measured between 6.8 Kgf and 7.4 Kgf at the basis weight of 78.2 g/m 2 and 79.5 g/m 2 respectively. The freeness of the furnish was between 27° and 29° implying that the tensile strength could have been better than that if adequate refining had been done. (Normally 35° to 37° gives at least 10% improvement in tensile strength) Relatively higher freeness of furnish implies that the UKP content in the Kraft paper was higher than 80%. Therefore, the above results verify that this invention successfully recovered UKP from OCC and transformed it into high UKP content Kraft paper. Since linerboard is essentially the same Kraft paper having different physical dimensions specified for the purpose of making corrugated container, the above examples on strength properties of Kraft paper readily apply to strength properties of linerboard. That is, when this invention is applied to conventional corrugated container mills, the strength properties of linerboard produced by applying this invention will readily satisfy those demanded in the market. Hence, we may say that this invention will make it possible to reproduce new corrugated container from OCC without adding any virgin UKP, and without sacrificing any strength properties of OCC.
A process for producing new corrugated containerboard from old corrugated container (OCC) without using expensive virgin UKP includes three new steps. These steps are separating corrugated medium from OCC before pulping linerboard, removing micro-fibrils from defibered linerboard furnish, and minimizing the loss of long fibers through reject streams of fine screens.
3
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to acoustic surface wave filters which comprises a transit time delay arrangement for a wave passing in one direction in the filter or can also comprise a resonator with an acoustic wave standing in the resonator and the invention can be applied to either of these two different filter arrangements. 2. Description of the Prior Art The publication "Electronics Letters", Volume 9, (1973), Pages 195-197 illustrates in FIG. 2 a 98 MHz oscillator which utilizes a filter of the type to which this invention relates. This filter utilizes a relatively wide band interdigital structure which has a length of r·λ and an interdigital structure which has a narrow band which has a length of p·λ. The narrow band interdigital structure is not completely filled over its length with digital strips or fingers as this would not be necessary for the narrow band condition but this elimination of certain of the fingers increases the insertion loss of the filter. Both of the interdigital structures of the prior art have the same predetermined mean or center frequency f 0 . The reason for not completely filling out a converter or transducer interdigital structure with digital strips, is to decrease the signal interferences (distortion signal through reflections to an interdigital structure of the filter. Such reflections are caused, for example, by waves which pass from the narrow band structure having a length of p·λ in the reverse direction due to reflection which waves impinge upon the wide band structure having a length r·λ and are reflected to the digital strips of such structure again and then proceed as time delay signals to the narrow band structure. A signal thus occurring at the narrow band structure is designated as a "triple transit" signal. The occurrence of such interfering or distortion signals causes a so-called "ripple" in the amplitude and frequency response F 0 ;φ 0 of the filter. In addition to the use of digital structures in which some of the fingers are missing, other methods have been proposed so as to more or less suppress the triple transit signal occurring because of the undesired multiple reflections caused by the interdigital structures. For example, the digital strips have been divided in one structure into two parallel strips connected with one another electrically with in each case having fingers which are only half as large as the width of the conventional fingers. Since, however, the maximum admissable width of a digital strip or finger is determined by the desirable frequency or particularly the mean frequency f 0 of the filter, the use of "split fingers" results in extreme requirements with respect to the manufacture of extremely narrow digital strips and also decreases the maximum useable frequency by a factor of 2 in a filter so constructed. SUMMARY OF THE INVENTION It is an object of the present invention to provide for suppression of signals which are based on reflections in interdigital structures of filters such as triple transit signals which can be realized without additional technical difficulties and which allow the high maximum frequency of the filter to be unchanged which could not be attained with split fingers. In addition to the advantages attained with respect to the upper frequency of the filter, the invention allows low insertion loss with an interdigital structure which can be filled out with a larger quantity of digital strips without having the interfering signal occur. The invention utilizes the feature that the amplitude characteristic or response F R of the triple transit interfering signal which is based upon among other things interdigital reflections by the wider band digital structure has two zero locations at frequencies f R1 and f R2 next below and above its center frequency which is the maximum of the frequency response F. These zero frequency locations f R1 and f R2 lie within the main lobe or maximum of the amplitude characteristic or response F 1 of the wider band interdigital converter or transducer structure and in the invention the main or center frequency f 1 of the digital structure with a wider band amplitude characteristic F 1 is shifted by a frequency Δf relative to the pregiven mean or center frequency f 0 and, thus, to shift it with respect to the mean or center frequency f 2 of the narrower band digital structure such that one of these two zero locations f R1 or f R2 which are related to the mean or center frequency f 1 of the wider band structure coincides substantially with the frequency f 0 of the filter. Because the band width of the narrower band width structure is smaller then the wider band width structure by a factor of at least two or preferably at least five, it will be assured that the interfering signal frequency F R will at most have only a smaller amplitude portion which falls into the pass band F 0 of the filter according to the invention. The invention can be utilized as a filter comprising a narrow band transit time delay line or, alternatively, the invention can be utilized as a filter comprising a resonator according to the invention. Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings although variations and modifications may be affected without departing from the spirit and scope of the novel concepts of the disclosure and in which BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 comprises a top plan view of a filter according to the invention in the form of a transit time delay line; FIG. 2 comprises a plot of the amplitude characteristic for a filter formed according to the prior art; FIG. 3 comprises a plot of the amplitude characteristics of a filter with dimensions selected according to the invention; and FIG. 4 comprises a plan view illustrating an embodiment of the filter wherein the invention is utilized as a resonator. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a design of the invention as a transit time delay line designated generally as 11 which comprises a piezoelectric substrate body 14 made of, for example, quartz or lithium niobate. A first interdigital structure 12 as, for example, an input converter is mounted on the substrate body 14 and a second interdigital structure 13 which may be an output converter is mounted on the substrate 14. The interdigital structure 13 has a geometric length of p·λ, and, thus, it has a relatively narrow frequency band width and a narrow frequency band width characteristic F 2 with a mean frequency of f 2 . The individually represented digital strips or fingers of the interdigital structures 12 and 13 are represented in FIGS. 1 and 4 as lines. The actual practice, they would have a width of, for example, 2 μm, for a maximum frequency of approximately 500 MHz. The lengths of the individual digital strips 17 is adjusted depending upon the signal power which is to be transmitted and in a specific example, the lengths can be 1 mm. The digital strips in the interdigital structures 12 and 13 are respectively alternatingly connected with ridges 121 and 122 in structure 12 and ridges 131 and 132 in structure 13. FIG. 1 only shows those details of the embodiment of a filter which are essential for the invention and such additional details such as connection lines which would be connected to the connection ridges 121 and 122, 131 and 132 are not shown. Neither are the acoustics sumps which would be applied to the end of the substrate are illustrated. If it be assumed that the digital structure 12 is an input converter then the acoustic surface wave which is generated piezoelectrically within structure 12 in the substrate body 14 which is indicated by the wavy line 15 will travel in the direction of the arrow 16 into the vicinity of the structure 13 of the output converter and will there be converted back from piezoelectric energy into an electrical signal wave. FIG. 2 is a diagram illustrating frequency as the abscissa and the amplitude is plotted as the ordinate. The amplitude characteristics are plotted with the amplitude characteristic F 1 for the relatively wide band interdigital structure 12. The amplitude characteristic F R is the characteristic of the signal of the interdigital reflections from the wider band width interdigital structure 12 (triple transit signal; TTS). The relationship of the amplitude characteristics F 1 and F 2 to each other according to FIG. 2 is the same in prior art devices wherein the mean frequency f 2 of the narrow band structure 13 lies generally at the mean frequency f 1 of the wide band structure. The total amplitude characteristic resulting corresponds due to the multiplication of the two amplitude characteristics F 1 and F 2 with each other with the precision which is necessary for observation and within the main maximum of the amplitude characteristic F 1 is shown in FIG. 2. The mean frequency f 0 of the entire filter 11 comprises the mean frequency f 2 of the amplitude characteristic F 2 . The wavy portion 21 of the upper part of curve F 1 results because of the superposition of the signal F R of the interdigital reflections (TTS signal). This waviness is designated as "ripple". The total amplitude characteristic F 0 of the filter has an interfering characteristic indicated by the dotted lines 22 in the amplitude characteristic F 2 . In a corresponding manner, the phase relationship curve of the filter over the frequency band will indicate interference in the phase characteristic. It has been determined for the amplitude characteristic F R of the signal caused by the interdigital reflections and supplied to the interdigital structure 12 plotted here in an isolated manner results in the curve designated by F R . The first two minima f R1 and f R2 fall within the main maximum 23 of the amplitude characteristic F 1 of the wider band structure 12. As shown, the zero locations f R1 and f R2 fall in each case at the half-way spacing between the main frequency f 1 and the points where the characteristic F 1 reaches zero. It has been observed that the amplitude characteristic F 1 of the wider band structure 12 in the case of these frequency values f R1 and f R2 does not have any significant drop compared to the bandwidth of the amplitude characteristic F 2 of the narrower band structure 13 in the relevant cases of the invention where the band width ratio of F 1 :F 2 is at least 2:1 and desirably more than 5:1. FIG. 3 is a frequency characteristic curve which illustrates the basis of the invention. F R in FIG. 3 illustrates the amplitude characteristic of the signal of the interdigital reflections supplied to the wider band structure and has zero locations at f R1 and f R2 . The amplitude characteristic F 1 does not have the waviness or ripple 21 of the prior art curve illustrated in FIG. 2 because it has been eliminated with the invention. In the present invention, the amplitude characteristic F 2 of the narrower band structure 13 is displaced by a frequency displacement of Δf from the mean frequency f 1 so that its mean frequency f 2 occurs at the frequency f R 1. The distance Δf is one half the distance from f 1 to a zero of F 1 . An equivalent solution shown by the broken line curve of the amplitude characteristic F 2 , has a mean frequency f 2 , falling at f R2 . Since for both solutions the zero locations of F R coincide with the mean frequency f 2 and f 2' of the narrow band structure and the amplitude characteristic F 1 does not have any substantial amplitude drop over the width of the main maximum of the amplitude characteristic f 2 of the narrower band structure 13 and there will no longer occur in the total amplitude characteristic F 0 due to the frequency offset Δf the amplitude interference which existed in the prior art structure such as shown in FIG. 2 and particularly in the maximum of the amplitude characteristic F 2 indicated by dotted line 22 in FIG. 2. The amplitude characteristic F 0 corresponds for the main maximum to the quantitative curve of the amplitude characteristic F 2 of the narrower band structure 13. Because the curve of the amplitude characteristic F 1 is unsymmetrical with the mean frequency f 2 , the submaxima due not result in unsymmetrical attenuation. The result of the invention is that a reflection of an acoustic wave which occurs from the narower band width structure 13 to the wider band structure 12 will be substantially suppressed and thus there will be no interfering triple transit signal. FIG. 4 illustrates an embodiment of the invention formed as a resonator 40 which has a piezoelectric substrate body 44 upon which at opposite ends the digital structures 41 and 141 are mounted. Also, the interdigital structures 42 and 43 are mounted as shown on the body 44. The interdigital structure 42 may be assumed to be the input converter and the interdigital structure 43 may be assumed to be the output converter although these, of course, can be interchanged if desired. In addition, in the resonator of FIG. 4 only one interdigital structure as 42 or 43 can comprise both the input and output converter. This depends upon the peripheral connecting circuit of the resonator. The digital structures 41 and 141 illustrated are in FIG. 4 in a manner which is known according to the prior art as reflector pairs which limit an acoustic resonator for the acoustic waves indicated by the wavy line 15 of the resonant filter. Between the two individual digital structures 41 and 141, a standing acoustic wave will occur which is indicated by the double arrow 46. The wave length of the standing wave in the resonator, that is the wave length corresponding to the resonant frequency of the resonator is determined by the dimensions of the periodicity of the digit strips of the two reflector structures 41 and 141 and the spacings of the interdigital structures 41 and 141 from each other. The spacing together with the measurement of the reflection characteristic of the two structures 41 and 141 determine the figure of merit or quality or Q-factor of the passive resonator cavity formed from the structures 41 and 141. The reciprocal of this Q-factor determines the relative bandwidth of the amplitudce characteristic F 2 which is formed from the two digital structures 41 and 141. Essentially because of the spacing of the digital structures 41 and 141 which form the reflectors generally the reflector pair 41 and 141 comprise the structure with the narrower band amplitude characteristic F 2 and phase characteristic of the resonator. In other words, in the case of the filter according to the invention as a resonator, the two digital structures 41 and 141 taken together form a single digital structure consisting of in each case a number of digital strips. The structures 41 and 141 which form reflectors do not require electrical connection. Thus, they can be designed merely as metal strips which are applied to the surface of the substrate body 44 and they also can be formed with corresponding strip-shaped surface indentations or, respectively, grooves in the substrate body or stripped shaped rails formed above the surface of the substrate body. The amplitude characteristic F 2 of the reflector pair 41 and 141 will have a mean frequency of f 2 . The reflector pair 41 and 141 correspond to the narrower band digital structure 13 illustrated in FIG. 1. As in the case of the transit time delay line illustrated in FIG. 1, the amplitude characteristic F 2 and its mean frequency f 2 determine the bandwidth F 0 and the mean frequency f 0 of the total resonator according to FIG. 4 because the smaller band width which is smaller by a factor of at least 2 or preferably 5 relative to the input and/or output converters 42 and 43. In the invention, the following equation results: ##EQU1## where f 0 is the known mean frequency of the filter and f 1 is the mean frequency which is to be selected according to the invention for the wider band digital structure. The total length l measure in the direction of the wave propagation direction 16 and 46 of the wider band digital structure 12 in FIG. 1 or in the case of the example of the resonator shown in FIG. 4 of the two structures 42 and 43 taken together is considered. In the example of FIG. 4, the total length l comprises the distance from the left side of the first digital strip of the structure 42 to the last digit at the right side of the structure 43 since the structures 42 and 43 together function as a single structure for the interdigital reflections of the interfacing signal F R which is to be eliminated. It is to be noted that the space between the structures 42 and 43 is not filled with digital strips completely. For this measurement of l, the factor N 1 of the acoustic wave lengths of the surface wave which fit into the length dimension and in each case must be utilized. Thus, N 1 ×λ=l as stated above and shown in FIG. 4. In the denominator wherein the plus and minus signs are used, depends on whether the case is f R1 to f 2 and of the situation of f R2 to f 2 . In the present invention, the interfering signals occurring due to interdigital reflections are eliminated. In a filter constructed accorded to the invention, the interfering signals from undesired reflections of acoustic waves passing to the left or right sides of the substrate body in each case can occur. So as to prevent such reflections from the ends of the substrate, it is desirable to cut the ends of the substrate bodies 14 and 44, respectively, on lines which are other than 90° relative to the direction of the arrow 15. This is not customary practice for resonator such as illustrated in FIG. 4 thus in the invention forming a resonator with tapered ends as shown in FIG. 4 substantially reduces end reflections. Although the invention has been described with respect to preferred embodiments, it is not to be so limited as changes and modifications can be made which are within the full intended scope of the invention as defined by the appended claims.
An acoustic wave filter comprising a piezoelectric substrate body upon which at least two digital structures are formed and which comprise input and output transducers and form a selective wave reflective pair with at least one of the digital structures having a wide band amplitude characteristic F1 and at least one of the other digital structures having a narrower frequency band amplitude characteristic and wherein the center frequency f1 of the wider band F1 digital structure is displaced relative to the center frequency f2 of the digital structure which has a narrower frequency band F2 by a frequency of Δ f on either side of the center frequency f1 so that one of the zero locations f R1'2 of the distortion signal F R of interdigital reflections is placed close to the value of the center frequency f 0 of the filter.
7
CROSS-REFERENCE TO RELATED APPLICATION This application claims priority from U.S. provisional application No. 60/897,355, filed Jan. 25, 2007. TECHNICAL FIELD The present invention relates to a device for purifying water and more specifically to a device to provide purified drinking water for personal use. BACKGROUND Potable (i.e., drinking) water is a necessity to which millions of people throughout the world have limited access. Water is often seen as the most basic and accessible element of life, and seemingly the most plentiful. There is no standard for how much water a person needs each day, but experts usually put the minimum at 100 liters for adults. Most people drink two or three liters—less than it takes to flush a toilet. The rest is typically used for cooking, bathing, and sanitation. Adult Americans consume between four hundred and six hundred liters of water each day. By 2050, there will be at least nine billion people on the planet, the great majority of them in developing countries. If water were spread evenly across the globe, there might be enough for everyone. But rain often falls in the least desirable places at the most disadvantageous times. More than a billion people lack access to drinking water. Simply providing access to clean water could save two million lives each year. Water purification processes are well known and used throughout the world. Water purification is the removal of contaminants from raw water to produce drinking water that is pure enough for human consumption. Substances that are removed during the process include parasites (such as Giardia or Cryptosporidium), bacteria, algae, viruses, fungi, minerals (including toxic metals such as lead, copper and arsenic), and man-made chemical pollutants. Many contaminants can be dangerous. Other contaminants are removed to improve the water's smell, taste, and appearance. It is not possible to tell whether water is safe to drink just by looking at it. Simple procedures such as boiling or the use of a household charcoal filter are not sufficient for treating water from an unknown source. Even natural spring water considered safe for all practical purposes in the 1800s must now be tested before determining what kind of treatment is needed. Water emerging from shallow groundwater is usually taken from wells or boreholes. The bacteriological quality can be variable depending on the source. Typically located in the headwaters of river systems, upland reservoirs are usually sited above any human habitation and may be surrounded by a protective zone to restrict the opportunities for contamination. Bacteria and pathogen levels are usually low, but some bacteria, protozoa or algae will be present. Low land surface waters, such as rivers, canals and low land reservoirs, will have a significant bacterial load and may also contain algae, suspended solids and a variety of dissolved constituents. Surface water may be contaminated with biological and chemical pollutants and may potentially transmit diseases such as diarrhea, dysentery, typhoid, cholera and hepatitis. Because of risk of contamination, surface water should never be used for drinking without treatment and/or disinfection. Many processes are available for purification of water, with their use depending on the particular contaminants present in the water. Ultrafiltration membranes are a relatively new development; they use polymer film having microscopic pores that can be used in place of granular media to filter water effectively without coagulants. The type of membrane media determines how much pressure is needed to drive the water through and what sizes of micro-organisms can be filtered out. In ultrafiltration, hydrostatic pressure forces a liquid against a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the filter up to about 0.01 microns in size. This removes bacteria and many viruses (which commonly adhere to the bacteria), but not salts (ions), while water and low molecular weight solutes pass through the membrane. It is desirable to have a reusable water filtration device that attaches to a water bottle or other portable water container and contains an ultrafiltration membrane. The device may provide a design that allows water to pass through the ultrafiltration membrane with minimal pressure. Preferably, the device includes a flushing mechanism that cleans the ultrafiltration membrane without having to disassemble the bottle cap. SUMMARY OF THE INVENTION It is an object of the invention to fulfill the need for a reusable bottle cap water filter that can provide purified drinking water free from bacterial contamination. Therefore, the present invention provides a portable and reusable apparatus for purification of water using an ultrafiltration membrane and requires only low pressure, such as may be generated by squeezing the bottle, sucking water through the opening of the bottle cap, or merely through the action of gravity. Preferably, the apparatus comprises a flushing mechanism that is useful for cleaning the ultrafiltration membrane without requiring disassembly of the apparatus. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross sectional view of an embodiment of a water filter unit device which may be attached to a water container. FIG. 2 is a cross section of a water container having an alternative embodiment attached to the top of the water container. FIG. 3 is a cross section of an alternative embodiment having an alternate means of back flushing FIG. 4 is a cross section of a water container and a filter unit which attaches to the top of a water container, with the filter extending into the water container. DETAILED DESCRIPTION At least one advantage of at least some embodiments is that these embodiments provide a reusable bottle cap water filter for use when attached to a water bottle, including an ultrafiltration membrane, and at least one one-way valve to prevent flow of water back into the water bottle. The ultrafiltration membrane is configured such that surface area is maximized, such as by elongated ultrafiltration membrane fibers, and does not require more than minimal pressure to pass water through the filter. The water filter of the present invention would be operable by squeezing the water bottle if the water bottle is made of a resilient polymer compressible skin, or other similar resilient material, thus forcing water through the water filter, by sucking on the outer opening of the bottle cap, thus forcing water through the filter (for use in a rigid polymer or metal container that do not compress), or merely by the action of gravity, inverting the water bottle and allowing water to pass through the filter. In one embodiment, the bottle cap water filter apparatus includes a flushing mechanism for cleaning the ultrafiltration membrane by forcing purified water back through the filter and into the water bottle, thereby flushing any particles off the surface of the ultrafiltration membrane. FIG. 1 is a drawing of one embodiment. The bottle cap may have an elongated, cylindrical shape. In this embodiment, the reusable bottle cap water filter apparatus is attachable to a water bottle, preferably via complementary threading such as on a screw cap. Immediately adjacent to the screw cap is a one-way valve with a mechanical shutoff to prevent water from flowing back through the membrane. With reference to FIG. 1 , screw cap 50 allows attachment of the water purification device onto a liquid holding container, such as a water bottle. In some applications an air intake tube 44 having an air intake inlet 46 to allow inlet of ambient air and an air intake outlet 48 extending into the bottle may be used to equalize pressure. During backflow, allowing air to leave the container may be desirable. During drinking, inlet 46 may be covered with a finger to prevent water from flowing through the tube. Water may be drawn through the system by a user sucking on opening 12 , by squeezing the bottle onto which the filtration device 10 is placed, or by inverting the bottle. When this is done, water will move past valve 40 into chamber 30 and through ultrafiltration membranes 32 . In the illustrated embodiment, the ultrafiltration membranes are tubular structures, having their open ends potted in membrane holder 34 , such that for water to pass from one side of membrane holder 34 to the other side of membrane holder 34 requires that the water first pass through membrane 32 . The water is drawn through a charcoal filter 18 retained within housing 14 . A user can then drink the water from opening 12 . To backflush the membrane, one way valve 16 is closed using mechanical shutoff 15 . This prevents water from flowing to opening 12 . Flushing mechanism 20 in this example is a simple bulb made of a resilient polymer material. Squeezing flushing mechanism will drive water back through the filtration membrane 32 , effectively back flushing the filter using filtered water. The pores of the ultrafiltration membrane will be cleared; allowing the filtration device to one again is used. Flow into the bottle can be stopped using one-way valve 40 controlled by mechanical shutoff 41 . With respect to FIG. 2 , the device of FIG. 1 is shown attached to bottle 60 . The threads on neck 62 of bottle 60 allow screw cap 50 to be screwed onto the bottle. With respect to FIG. 3 , an alternative embodiment is shown. As before, a screw cap 50 allows attachment to the bottle, an air intake tube 44 includes an inlet 46 and an outlet 48 to allow air to be displaced from a bottle or other container to which the device is attached. As water is drawn into chamber 30 , it filters through filter membrane 32 , flows through membrane holder 34 and is drawn by the user through opening 12 . Here arms 13 attached to mechanical actuator 55 allow the purging of water from chamber 9 by mechanically intruding arms 13 into chamber 9 , which mate to displace some of the contents of chamber 9 . It will be readily understood that a number of different mechanisms may be used for back flushing membrane 32 . Any mechanism that reduces the size of chamber over the membrane will cause liquid to be back flushed through the membrane. With reference to FIG. 4 , bottle 60 is shown having a neck 62 , which may taper. Held at this neck is membrane 32 held in membrane holder 34 . Membrane holder 34 may be held in neck 62 that tapers. The housing 14 of the water filtration device has a lip 11 which may snap over an annular lip on neck 62 , attaching the filtration device onto the bottle 60 . As in FIG. 1 , the purified water flows through opening 12 and water may be purged by shutting one-way valve 16 and squeezing flushing mechanism 20 . The apparatus of the above embodiments preferably uses an ultrafiltration membrane capable of filtering bacteria from water, to provide potable water free of contamination. The ultrafiltration membrane of the preferred embodiment has a maximized surface area, produced by stretching the ultrafiltration membrane into tubular filaments. The ultrafiltration membrane used in the preferred embodiment is made from Ultra-Flo DUC 108 ultrafiltration membrane from Ultra-Flo PTE Ltd., 452 Tasgore Industrial Avenue, Singapore 787823. This is described in co-pending application Ser. No. 11/941,713 hereby expressly incorporated by reference for all purposes herein. One embodiment also optionally contains a charcoal filter to further purify and enhance the taste of the water exiting the filter. At the outlet opening of the apparatus is a second, optional one-way valve with mechanical shutoff to prevent water from flowing back into the water bottle during flushing. One problem with ultrafiltration membranes is clogging by particles and bacteria. In the illustrated embodiments, some water is retained within the housing of the filtration device 10 of FIG. 1 to keep the ultrafiltration membrane wet. Further, additional water is retained in the apparatus at a point subsequent to passing through the ultrafiltration membrane. These embodiments contain a flushing mechanism to force the retained water back in the direction of the water bottle, passing through the ultrafiltration membrane in the opposite direction. By flushing water back through the membrane, the filter is thereby cleaned of any particles sticking to it. As depicted in FIG. 1 , the flushing mechanism is a portion of the bottle cap that is capable of being compressed or squeezed, creating pressure that forces the water back in the opposite direction. Alternatively, the flushing mechanism is comprised of complementary threaded portions of the bottle cap such that they can be screwed together to compress the area inside the cap and force water back through the ultrafiltration membrane. One advantage of the flushing device of the present invention is that the bottle cap water filter does not need to be taken apart in order to clean the ultrafiltration membrane. By providing the flushing mechanism and a bottle cap water filter that is a single unit that cannot be disassembled, the present invention protects the ultrafiltration membrane from any damage or drying out that could be caused by disassembly.
An apparatus for producing purified drinking water. The apparatus comprises a container top including an ultrafiltration insert. The container top attaches to the opening of a liquid holding container, such that liquid from the container passes through a filter. The device includes a mechanism for back flushing or cleaning the filter. The resulting water is substantially pure, being free of bacteria, to make it safe for drinking.
1
CROSS-REFERENCE TO RELATED APPLICATION This application is a divisional of U.S. patent application Ser. No. 08/634,783 filed Apr. 19, 1996, now U.S. Pat. No. 5,861,276. TECHNICAL FIELD The present invention relates to cDNAs encoding murine monoclonal antibody against apolipoprotein B-100, the protein of low-density lipoproteins(LDL) in human plasma. More specifically, the present invention relates to cDNAs encoding heavy chain and light chain of murine monoclonal antibody which recognizes and binds to apolipoprotein B-100. Apolipoprotein B-100 is the major protein moiety of LDL which plays an important role in the plasma lipid metabolism, transporting cholesterol from liver to necessary peripheral tissue. BACKGROUND OF ART Apolipoprotein B-100, the protein of low density lipoproteins in human plasma, is reported to be a more reliable positive index than former cholesterol index of LDL-cholesterol, for diagnosis of cardiovascular diseases, such as arteriosclerosis, coronary artery disease, and the like [Brustolin, D. et al., Clin. Chem. 37: 742-747 (1991); Dona, V. et al., Giorn. It. Chim. Clin. 12: 205-214 (1987)]. The specific monoclonal antibody can be used as a diagnostic agent to measure the concentration of apolipoprotein B-100 in blood conveniently and reliably for the global risk estimation of cardiovascular diseases. In addition the specific monoclonal antibody against apolipoprotein B-100 can be used for specific binding and removal of the high level of blood LDL for the treatment of cardiovascular diseases. Therefore, it is necessary to produce specific monoclonal antibodies against apolipoprotein B-100. SUMMARY OF THE INVENTION The object of the present invention is to provide cloned cDNAs, which encode antigen-binding fragment(Fab) of murine monoclonal antibodies binding specifically with human plasma apolipoprotein B-100. These monoclonal antibodies are MabB9 with IgG2b heavy chain and kappa light chain, and MabB23 with IgG2b heavy chain and lambda light chain. The hybridoma cells producing MabB9 and MabB23, H-MabB9 and H-MabB23, respectively, have been deposited with the Korean Collection for Type Cultures, Genetic Engineering Research Institute ("GERI"), KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea, as accession numbers KCTC 0104 BP (H-MabB9) and KCTC 0105 BP (H-MabB23) on Mar. 23, 1994 [Reference Patent Application #94-12084, Republic of Korea, May 31, 1994] The object of the present invention is to provide cDNAs of heavy chain gene(B9H) (SEQ ID NO: 1) and light chain gene(B9L) (SEQ ID NO: 2), which encode antigen-binding fragment (Fab) of murine monoclonal antibody, MabB9, and to provide cDNAs of heavy chain gene(B23H) (SEQ ID NO: 3) and light chain gene(B23L) (SEQ ID NO: 4), which encode the Fab fragment of murine monoclonal antibody, MabB23. And the object of the present invention is to provide Escherichia coli transformant, TG1/pB9HT7, containing the vector pB9HT7, in which the heavy chain gene, B9H (SEQ ID NO: 1), is inserted(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0197 BP; accession date: Oct. 6, 1995) and E. Coli transformant, TG1/pB9LBlue, containing the vector pB9LBlue, in which the light chain gene, B23H (SEQ ID NO: 3), is inserted(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0198 BP; accession date: Oct. 6, 1995). And the object of the present invention is to provide E. coli transformant, TG1/pB23HT7, containing the vector pB23HT7, in which the heavy chain gene, B23H (SEQ ID NO: 3), is inserted(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0199 BP; accession date: Oct. 6, 1995) and E. coli transformant, TG1/pB23LBlue, containing the vector pB23LBlue, in which the former light chain gene, B23L (SEQ ID NO: 4), is inserted(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0199 BP; accession date: Oct. 6, 1995). In addition, the object of the present invention is to provide the method of preparation of recombinant antibody against human plasma lipoprotein B-100 by expressing the cloned cDNAs via the construction of an expression vector for appropriate host cells such as E. coli. In addition, the object of the present invention is to provide the use of recombinant antibody against human plasma apolipoprotein B-100 for diagnosis of cardiovascular diseases by allowing measurement of the concentration of human plasma apolipoprotein B-100. In addition, the object of the present invention is to provide the use of recombinant antibody against human plasma apolipoprotein B-100 for treatment of cardiovascular diseases by allowing the specific binding and removal of the high level LDL or other apolipoprotein B-100 containing harmful substances from blood. In the following, the present invention will be described in detail. BRIEF DESCRIPTION OF FIGURES FIG. 1 shows the structure and restriction map of pB9HT7 vector containing 690 bp cDNA SEQ. ID No. 1 of the heavy chain (B9H) of murine monoclonal antibody, MabB9, against human plasma apolipoprotein B-100, prepared according to this invention. FIG. 2 shows the structure and restriction map of pB9LBlue vector containing 642 bp cDNA SEQ. ID No. 2 of the light chain (B9L) of murine monoclonal antibody, MabB9, against human plasma apolipoprotein B-100, prepared according to this invention. FIG. 3 shows the structure and restriction map of pB23HT7 vector containing 693 bp cDNA SEQ. ID No. 3 of the heavy chain (B23H) of murine monoclonal antibody, MabB23, against human plasma apolipoprotein B-100, prepared according to this invention. FIG. 4 shows the structure and restriction map of pB23LBlue vector containing 642 bp CDNA SEQ. ID No. 4 of the light chain (B23L) of murine monoclonal antibody, MabB23, against human plasma apolipoprotein B-100, prepared according to this invention. FIG. 5 shows nucleotide sequence SEQ ID NO: 1 and deduced amino acid sequence of CDNA (B9H) encoding the heavy chain of murine monoclonal antibody, MabB9, against human plasma apolipoprotein B-100, prepared according to this invention. CDR 1, 2, 3 sequences within V-region and C H 1-region (from nucleotide No. 355) are underlined. Unusual amino acids found when compared with those of mouse heavy chain subgroup II(B) are indicated with dotted line under the very amino acid. FIG. 6 shows nucleotide sequence SEQ ID NO: 2 and deduced amino acid sequence of cDNA (B9H) encoding light chain of murine monoclonal antibody, MabB9, against human plasma apolipoprotein B-100, prepared according to this invention. CDR 1, 2, 3 sequences within V-region and C K 1-region (from nucleotide No. 322) are underlined. FIG. 7 shows nucleotide sequence SEQ ID NO: 3 and deduced amino acid sequence of cDNA (B23H) encoding the heavy chain of murine monoclonal antibody, MabB23, against human plasma apolipoprotein B-100, prepared according to this invention. CDR 1, 2, 3 sequences within V-region and C H 1-region (from nucleotide No. 358) are underlined. Unusual amino acids found when compared with those mouse heavy chain subgroup I(B) are indicated with dotted line under the very amino acid. FIG. 8 shows nucleotide sequence SEQ ID NO: 4 and deduced amino acid sequence of cDNA (B23L) encoding the light chain of murine monoclonal antibody, MabB23, against human plasma apolipoprotein B-100, prepared according to this invention. CDR 1, 2, 3 sequences within V-region and C.sub.λ 1-region (from nucleotide No. 331) are underlined. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hybridoma cells producing murine monoclonal antibody against human plasma apolipoprotein B-100 are cultured with optimal media, such as RPMI medium, (Sigma, R-6504) and harvested. Then, the total RNAs of the cells are extracted by acid guanidium thiocyanate-phenol-chloroform method and the like. Also, the poly(A) + RNA is purified by oligo(dT)-cellulose chromatography method [Aviv, H. and Leder, P., Proc. Natl. Acad. Sci. USA, 69: 1408-1412, 1972]. Next, the first strand of cDNA is synthesized by using reverse transcriptase and oligo(dT) 15 primer. In order to get the cDNAs encoding heavy chain and light chain of antibody, polymerase chain reaction(PCR) is performed by Taq DNA polymerase using the specific oligonucleotide primers corresponding to N-terminal and C-terminal sequences of the heavy and light chains of antibody. The N-terminal primer used is synthesized according to the data obtained from N-terminal sequencing of the purified heavy and light chain proteins of the antibody, and the C-terminal primer used is obtained according to the constant region sequences of the heavy and light chains of the antibody. The DNA fragments obtained by the polymerase chain reactions are cloned into proper vectors, such as pT7Blue(Novagen, USA) and pBluescript(Stratagene, USA). Nucleotide sequences of the cloned cDNAs are determined by chain termination method using dideoxy nucleotides and the like [Sanger, F. et al., Proc. Natl. Acad. Sci. USA, 76: 4350-4354, 1977]. The following examples will further illustrate the present invention, which by no means limit the present invention. EXAMPLE 1 mRNA purification from hybridoma cells producing monoclonal antibodies against human plasma apolipoprotein B-100 The hybridoma cells, H-MabB9(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0104 BP; accession date: Mar. 23, 1994) producing monoclonal antibody MabB9 (IgG2b, kappa) against human plasma apolipoprotein B-100, and H-MabB23(depositary authority: Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea; accession number: KCTC 0105 BP; accession date: Mar. 23, 1994) producing monoclonal antibody MabB23 (IgG2b, lambda) were made by the process, wherein pancreatic cells of Balb/c mouse and myeloma cell that has been previously immunized with human apolipoprotein B-100 were fused with the myeloma cells of Sp2/O-Ag-14 by the well-established hybridoma technique established well [Kohler, G. and Milstein, C., Nature, 256: 495-497, 1975; Galfre, G. et al., Nature, 256: 550-552, 1977]. These hybridoma cells were cultured in optimal media, such as RPMI medium (Sigma, R-6504), and harvested. Then, the total cellular RNA was extracted by acid guanidium thiocyanate-phenol-chloroform method [Puissant, C. and Houdebine, L. M., Biotechnique, 8: 148-149, 1990]. And the poly (A)+RNA was purified by oligo(dT)-cellulose chromatography method [Aviv, H. and Leder, P., Proc. Natl. Acad. Sci. USA, 69: 1408-1412, 1972] EXAMPLE 2 N-terminal amino acid sequencing of heavy and in light chains of monoclonal antibody MabB9 against human plasma apolipoprotein B-100. Murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100 was mixed with Laemmli's sample buffer [Laemmli, E. K., Nature, 227: 680-685, 1970], including mercaptoethanol. The antibody was separated by SDS-polyacrylamide gel electrophoresis and transferred onto PVDF membrane by electroblotting method [Towbin, H. et al., Proc. Natl. Acad. Sci. USA, 76: 4350-4354, 1979). Then, about 50-kD band corresponding to the heavy chain and 25-kD band corresponding to light chain of monoclonal antibody MabB9 were cut to analyze their N-terminal amino acid sequences by amino acid sequence analyzer. As a result, the N-terminal amino acid sequence of the heavy chain of monoclonal antibody MabB9 was determined as E-V-Q-L-V-E--S--G-A-E SEQ. ID No. 5 and that of the light chain of MabB9 was determined as D-I-K-M-T-Q--S--P--S--S SEQ. ID No. 6. EXAMPLE 3 N-terminal amino acid sequencing of heavy and light chains of monoclonal antibody MabB23 against human plasma apolipoprotein B-100. Murine monoclonal antibody MabB23 against human plasma apoliporotein B-100 was incubated with Laemmli's sample buffer. The antibody was separated by SDS-polyacrylamide gel electrophoresis and transferred onto PVDF membrane by electroblotting method. Then, about 50-kD band corresponding to the heavy chain and 25-kD band corresponding to light chain of monoclonal antibody MabB23 were cut to analyze their N-terminal amino acid sequences by amino acid sequence analyzer. As a result, the N-terminal amino acid sequence in heavy chain of monoclonal antibody MabB23 was determined as E-V-Q-L-V-E--S--G-P-G SEQ. ID No. 7 and that in light chain of monoclonal antibody MabB23 as Q-A-V-V-T-Q-E--S--A-L SEQ. ID No. 8. EXAMPLE 4 cDNA cloning of heavy and light chains of murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100. To synthesize the first strand of cDNA, 1 μg of poly (A) + RNA of H-MabB9 Hybridoma cell purified in Example 1 was incubated with 1 mM each of 4 dNTPs, 50 units of RNasin (Boehringer Mannheim, USA), 80 pmoles of oligo d(T) 15 primer and 15 unit of AMV reverse transcriptase in 20 μl of the reaction buffer [50 mM KCl, 50 mM Tris-Cl(pH8.3), 10 mM MgCl 2 , 1 mM spermidine, 10 mM DTT, 4 mM sodium pyrophosphate] at 42° C. for 1 hr. Then, N-terminal and C-terminal oligonucleotide primers and 2 units of Taq DNA polymerase were added to perform the polymerase chain reaction (PCR). The N-terminal oligonucleotide primers were synthesized according to the codons of N-terminal amino acid sequences determined in Example 2, and the C-terminal oligonucleotide primers were synthesized according to the constant region sequences of IgG2b heavy chain and kappa light chain of monoclonal antibody MabB9. The PCR was performed according to the steps, wherein the reaction mixture was incubated initially at 94° C. for 15 sec, at 57° C. for 10 sec and at 72° C. for 15 sec, and then at 94° C. for 5 sec, at 57° C. for 10 sec, at 72° C. for 15 sec sequentially and repeatedly for 33 cycles, and finally at 94° C. for 15 sec, at 57° C. for 10 sec and at 720C for 120 sec. As a result, 690 bp of DNA fragment corresponding to Fab region of the heavy chain of monoclonal antibody MabB9 was obtained. The DNA fragment was cloned into pT7Blue(Novagene, USA) phagemid vector to construct pB9HT7 containing B9H, the heavy chain cDNA of monoclonal antibody MabB9. The structure and restriction map of pB9HT7 is shown in FIG. 1. Likewise, 642 bp DNA fragment corresponding to the light chain of monoclonal antibody MabB9 was obtained and cloned into pBluescript(Stratagene, USA) phagemid vector to construct pB9LBlue containing B9L, light chain cDNA of monoclonal antibody MabB9. The structure and restriction map of pB9LBlue is shown in FIG. 2. With the above described vectors, Escherichia coli TG1 strains were transformed to obtain TG1/pB9HT7 and TG1/pB9LBlue. And the strains were deposited with the Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea, on Oct. 6, 1995(respective accession numbers: KCTC 0197 BP and KCTC 0198 BP). EXAMPLE 5 CDNA cloning of heavy and light chains of murine monoclonal antibody MabB23 against human plasma apolipoprotein B-100 1 μg of poly(A) + RNA of H-MabB23 hybridoma cell purified in Example 1 was incubated with AMV reverse transcriptase, and the same method as described in Example 4 was performed to synthesize the first strand cDNA. Then, N-terminal oligonucleotide primers synthesized according to the N-terminal amino acid sequencing data obtained in Example 3 for the heavy and light chains of monoclonal antibody MabB23, and C-terminal oligonucleotide primers synthesized according to the constant region sequences of the IgG2b heavy chain and lambda light chain, were added to perform the PCR reactions using the same reaction conditions as described in Example 4. As a result, 693 bp DNA fragment corresponding to Fab region of the heavy chain of monoclonal antibody MabB23 was obtained. The DNA fragment was cloned into pT7Blue vector to construct pB23HT7 containing B23H, the heavy chain cDNA of monoclonal antibody MabB23. The structure and restriction map of pB23HT7 is shown in FIG. 3. Likewise, 642 bp DNA fragment corresponding to the light chain of monoclonal antibody MabB23 was obtained, and cloned into pBluescript vector to construct pB23LBlue containing B23L, the light chain cDNA of monoclonal antibody MabB23. The structure and restriction map of pB23LBlue is shown in FIG. 4. With the above-described vectors, Escherichia coli TG1 strain was transformed to obtain TG1/pB23HT7 and TG1/pB23LBlue. The strains were deposited with the Korean Collection for Type Cultures, Genetic Engineering Research Institute, KIST, P.O. Box 115, Yusong, Taejon, 305-600, Republic of Korea, on Oct. 6, 1995 (respective accession number: KCTC 0199 BP and KCTC 0200 BP) EXAMPLE 6 Nucleotide sequencing of heavy chain CDNA of murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100 To determine the nucleotide sequence of the heavy chain cDNA of the murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100, double stranded or single stranded phagemid DNA of pB9HT7 which contains the heavy chain cDNA(B9H) cloned in Example 4 was purified by SDS-alkaline extraction method [Birnboim, H. C., Methods Enzymol., 100: 243-255, 1983]. Nucleotide sequence of the antibody cDNA was determined by chain termination method using dideoxy nucleotides [Sanger, F. et al., Proc. Natl. Acad. Sci. USA, 74: 5463-5467, 1977], wherein the nucleotide sequence was fully determined on both orientations using M13 universal primer or synthetic internal primers. The determined nucleotide sequence SEQ ID NO: 1 of MabB9 heavy chain cDNA in MabB9 is shown in FIG. 5. When compared with the reported immunoglobulin heavy chain cDNA sequences, it was found that the heavy chain CDNA of MabB9, B9H, belongs to mouse heavy chain subgroup II(B) [Kabat, E. A. et al., Sequences of Proteins of Immunological Interest, 5th ed., US Department of Human Services, Public Health Service, National Institute of Health, Bethesda, Md., 1991]. The V(variable)-region was located between amino acid number(No.) 1 and No. 118 and CH1-region located from No. 119. And V-region also contained unique CDR(complementarity determining sequences) 1, 2, 3 sequences, located between amino acid No. 31 and No. 35 (CDR 1), between No. 50 and No. 66 (CDR 2) and between No. 99 and No. 107 (CDR 3), which confer antigen- binding specificity. 7 Cysteine residues were found at amino acid numbers 22, 96, 133, 145, 200, 227 and 230, which would participate in disulfide bonding to form Fab structure of antibody. When compared with the V-region sequence profiles of mouse heavy chain subgroup II(B) [Harris, L. and Bajorath, J., Protein Sci. 4: 306-310, 1995], some unusual amino acids were found at the following locations: Met (No. 13), Thr(No. 25), Thr(No. 48) and Phe (No. 70). EXAMPLE 7 Nucleotide sequencing of light chain cDNA of murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100. To determine the nucleotide sequence of the light chain cDNA of the murine monoclonal antibody MabB9 against human plasma apolipoprotein B-100, double stranded or single stranded phagemid DNA of pB9LBlue which contains the light chain cDNA (B9L) cloned in Example 4 was purified by the SDS-alkaline extration method [Birnboim, H. C., 1983]. Nucleotide sequence of the antibody cDNA was determined by the chain termination method using dideoxy nucleotides [Sanger, F. et al., 1977], wherein the nucleotide sequence was fully determined on both orientations using M13 universal primer or synthetic internal primers. The nucleotide sequence SEQ ID NO: 2 of MabB9 light chain cDNA is shown in FIG. 6. When compared with the reported immunoglobulin light chain cDNA sequences, it was found that the light chain cDNA of MabB9, B9L, belongs to mouse kappa chain subgroup V [Kabat, E. A. et al., 1991]. The V-region was located between amino acid No. 1 and No. 107 and C K -region located from No. 108. And V-region also contained unique CDR 1,2,3 sequences, located between amino acid No. 24 and No. 34 (CDR 1), between No. 50 and No. 56 (CDR 2) and between No. 89 and No. 97 (CDR 3), which confer antigen-binding specificity. 5 Cysteins were found at amino acid numbers 23, 88, 134, 194 and 214, which would participate in disulfide bonding to form Fab structure of antibody. As illustrated in Example 6 and Example 7, cDNAs encoding the heavy chain and light chain of the antigen-binding fragment (Fab) of monoclonal antibody MabB9 (IgG2b, kappa) against apolipoprotein B-100, the protein moiety of low-density lipoproteins(LDL) was shown to have all the requirements of antibody. Unique CDR sequences and some unusual amino acids were also found. These results strongly suggest that the cDNAs are functional. The sequences were submitted to the GenBank/EMBL Data Libraries and have acquired the accession numbers of U28968 (heavy chain CDNA of MabB9; B9H, SEQ ID NO: 1) and U28969 (light chain cDNA of MabB9; B9L, SEQ ID NO: 2)(The sequences release date is Jan. 1, 1997). EXAMPLE 8 Nucleotide sequencing of heavy chain CDNA of murine monoclonal antibody MabB23 against human plasma apolipoprotein B-100. To determine the nucleotide sequence of heavy chain CDNA, B23H in murine monoclonal antibody MabB23 against human plasma apolipoprotein B-100, double stranded or single stranded phagemid DNA of pB23HT7 which contains the heavy chain cDNA (B23H) cloned in Example 5 was purified. Then, the same method as described in Example 6 was performed for nucleotide sequencing SEQ ID NO: 3. The determined nucleotide sequence of MabB23 heavy chain cDNA in MabB23 is shown in FIG. 7. When compared with the reported immunoglobulin heavy chain cDNA sequences, it was found that the heavy chain cDNA of MabB23, B23H, belongs to mouse heavy chain subgroup I(B) [Kabat, E. A. et al., 1991]. The V-region was located between amino acid No. 1 and No. 119 and C H 1-region located from No. 120. And the V-region contained unique CDR 1,2,3 sequences, located between amino acid No. 31 and No. 35 (CDR 1), between No. 50 and No. 65 (CDR 2) and between No. 98 and No. 108 (CDR 3), which confer antigen-binding specificity. 7 Cysteins were found at amino acid numbers 22, 95, 134, 146, 201, 228 and 231, which would participate in disulfide bonding to form Fab structure of antibody. When compared with V-region sequence profiles of mouse heavy chain subgroup I(B) [Harris, L. and Bajorath, 1995], some unusual amino acids were found at the following locations: Glu (No. 1), Val (No. 5) and Val (No. 96). A new amino acid in the heavy chain constant region, Arg(AGG) at amino acid No. 133 instead of Gly(GGG) was found, which has not been hitherto reported. EXAMPLE 9 Nucleotide sequencing of light chain cDNA of murine monoclonal antibody MabB23 against human plasma apolipoprotein B-100. To determine the nucleotide sequence of light chain cDNA of the murine monoclonal antibody MabB23 against human plasma apolipoprotein B-100, double stranded or single stranded phagemid DNA of pB23LBlue which contains light chain CDNA (B23L) cloned in Example 5 was purified. Then the same method as described in Example 6 was performed for nucleotide sequencing. The determined nucleotide sequence SEQ ID NO: 4 of MabB23 light chain cDNA is shown in FIG. 8. When compared with the reported immunoglobulin light chain cDNA sequence, it was found that the light chain cDNA of MabB23, B23L belongs to a typical mouse lambda chain [Kabat, E. A. et al., 1991]. The V-region was located between amino acid No. 1 and No. 110 and C.sub.λ -region located from No. 111. And the V-region contained unique CDR 1,2,3 sequences, located between amino acid No. 23 and No. 36 (CDR 1), between No. 52 and No. 58 (CDR 2), and between No. 91 and No. 99 (CDR 3), which confer antigen- binding specificity. 5 Cysteins were found at amino acid numbers 22, 90, 137, 196 and 214, which would participate in disulfide bonding to form Fab structure of antibody. As illustrated in Example 8 and Example 9, cDNAs encoding the heavy chain and light chain of the antigen-binding fragment (Fab) of monoclonal antibody MabB23 (IgG2b, lambda) against apolipoprotein B-100, the protein moiety of low-density lipoproteins(LDL) were shown to have all the sequence requirements of antibody. Unique CDR sequences and some unusual amino acids were also found. These results strongly suggest that the cDNAs are functional. The sequences were submitted to the GenBank/EMBL Data Libraries and have acquired the accession numbers of U28970 (heavy chain cDNA of MabB23; B23H SEQ ID NO: 3) and U28967 (light chain cDNA of MabB23; B23L SEQ ID NO: 4)(The sequences release date is Jan. 1, 1997). cDNAs of the present invention can be used for expression in microorganisms of the recombinant Fab antibodies specific for human plasma apolipoprotein B-100 of LDL. The recombinant antibodies can be utilized as a diagnostic agent to measure the concentration of plasma apolipoprotein B-100, a positive index for cardiovascular diseases and in global risk assessment of the disease. In addition, the recombinant antibodies can be used for development of an immunotherapeutic protein which can specifically bind with the harmful LDL-containing substances in blood for subsequent removal from circulation in relation to the development of arterosclerosis. __________________________________________________________________________# SEQUENCE LISTING - - - - (1) GENERAL INFORMATION: - - (iii) NUMBER OF SEQUENCES: 8 - - - - (2) INFORMATION FOR SEQ ID NO:1: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 690 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: - - GAGGTGCAGC TGGTGGAGTC TGGAGCTGAG CTGATGAAGC CTGGGGCCTC AG -#TGAAGATA 60 - - TCCTGCAAGG CTACTGGCTA CACATTCAGT AGCTACTGGA TAGAGTGGAT AA -#AGCAGAGG 120 - - CCTGGACATG GCCTTGAGTG GACTGGAGAG ATTTTACCTG GAAGTGGTAC TA -#CTAAATAC 180 - - AATGAGAAGT TCAAGGACAA GGCCACATTC ACTGCAGATA CATCCTCCAA CA -#CAGCCTAC 240 - - ATGCAACTCA GCAGCCTGAC ATCTGAGGAC TCTGCCGTCT ATTACTGTGC AA -#GATCGTAT 300 - - AGGTACGCCC CTATGGACTA CTGGGGTCAA GGAACCTCAG TCACCGTCTC CT -#CAGCCAAA 360 - - ACAACACCCC CATCAGTCTA TCCACTGGCC CCTGGGTGTG GAGATACAAC TG -#GTTCCTCC 420 - - GTGACTCTGG GATGCCTGGT CAAGGGCTAC TTCCCTGAGT CAGTGACTGT GA -#CTTGGAAC 480 - - TCTGGATCCC TGTCCAGCAG TGTGCACACC TTCCCAGCTC TCCTGCAGTC TG -#GACTCTAC 540 - - ACTATGAGCA GCTCAGTGAC TGTCCCCTCC AGCACCTGGC CAAGTCAGAC CG -#TCACCTGC 600 - - AGCGTTGCTC ACCCAGCCAG CAGCACCACG GTGGACAAAA AACTTGAGCC CA -#GCGGGCCC 660 - - ATTTCAACAA TCAACCCCTG TCCTCCATGC - # - # 690 - - - - (2) INFORMATION FOR SEQ ID NO:2: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 642 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: - - GATATCAAGA TGACCCAGTC TCCATCTTCC ATGTATGCAT CTCTAGGAGA GA -#GAGTCACT 60 - - ATCACTTGCA AGGCGAGTCA GGACATTTAT AGCTATTTAA GCTGGTTCCA GC -#AGAAACCA 120 - - GGGAAATCTC CTAAGACCCT GATCTATCGT GCAAACAGAT TGGTCGATGG GG -#TCCCATCA 180 - - AGGTTCAGTG GCAGTGGATC TGGGCAAGAT TATTCTCTCA CCATCAGCAG CC -#TGGAGTAT 240 - - GAAGATCTGG GAATTTATTA TTGTCTACAG TTTGATGAGT TTCCGTACAC GT -#TCGGAGGG 300 - - GGGACCAAGC TGGAAATAAA ACGGGCTGAT GCTGCACCAA CTGTATCCAT CT -#TCCCACCA 360 - - TCCAGTGAGC AGTTAACATC TGGAGGTGCC TCAGTCGTGT GCTTCTTGAA CA -#ACTTCTAC 420 - - CCCAAAGACA TCAATGTCAA GTGGAAGATT GATGGCAGTG AACGACAAAA TG -#GCGTCCTG 480 - - AACAGTTGGA CTGATCAGGA CAGCAAAGAC AGCACCTACA GCATGAGCAG CA -#CCCTCACG 540 - - TTGACCAAGG ACGAGTATGA ACGACATAAC AGCTATACCT GTGAGGCCAC TC -#ACAAGACA 600 - - TCAACTTCAC CCATTGTCAA GAGCTTCAAC AGGAATGAGT GT - # - # 642 - - - - (2) INFORMATION FOR SEQ ID NO:3: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 693 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: - - GAGGTGCAGC TGGTGGAGTC AGGACCTGGC CTGGTGGCGC CCTCACAGAG CC -#TGTCCATC 60 - - ACGTGCACTG TCTCAGGGTT CTCATTAACC GACTATGGTG TAAGCTGGAT TC -#GCCAGCCT 120 - - CCAGGAAAGG GTCTGGAGTG GCTGGGAGTA ATTTGGGCTG GTGGAAGCAC AT -#TCTATAAT 180 - - TCAGCTCTCA AGTCCAGACT GAGCATCAAC AAGGACAACT CCAAGAGCCA AG -#TTTTCTTA 240 - - AAAATGAACA GTCTGCACAC TGATGACACA GCCATGTACT ACTGTGTCAA AC -#ATGAGGAT 300 - - AGGTACGACT GGTACTTCGA TGTCTGGGGC GCAGGGACCA CGGTCACCGT CT -#CCTCAGCC 360 - - AAAACAACAC CCCCATCAGT CTATCCACTG GCCCCTAGGT GTGGAGATAC AA -#CTGGTTCC 420 - - TCCGTGACTC TGGGATGCCT GGTCAAGGGC TACTTCCCTG AGTCAGTGAC TG -#TGACTTGG 480 - - AACTCTGGAT CCCTGTCCAG CAGTGTGCAC ACCTTCCCAG CTCTCCTGCA GT -#CTGGACTC 540 - - TACACTATGA GCAGCTCAGT GACTGTCCCC TCCAGCACCT GGCCAAGTCA GA -#CCGTCACC 600 - - TGCAGCGTTG CTCACCCAGC CAGCAGCACC ACGGTGGACA AAAAACTTGA GC -#CCAGCGGG 660 - - CCCATTTCAA CAATCAACCC CTGTCCTCCA TGC - # -# 693 - - - - (2) INFORMATION FOR SEQ ID NO:4: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 642 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: - - CAGGCTGTTG TGACTCAGGA ATCTGCACTC ACCACATCAC CTGGTGAAAC AG -#TCACACTC 60 - - ACTTGTCGCT CAAATACTGG GGCAGTTACA ACTAGTAACT ATGCCAGCTG GG -#TCCAAGAA 120 - - AAACCAGATC ATTTATTCAC TGGTCTAATA GGTGGTACCA ACAACCGAGT TC -#CAGGTGTT 180 - - CCTGCCAGGT TCTCAGGCTC CCTGATTGGA GACAAGGCTG CCCTCACCAT CA -#CAGGGGCA 240 - - CAGACTGAGG ATGAGGCAAT ATATTTCTGT GCTCTATGGA ACAGCAACCA CT -#GGGTGTTC 300 - - GGTGGAGGAA CCAAACTGAC TGTCCTAGGC CAGCCCAAGT CTTCGCCATC AG -#TCACCCTG 360 - - TTTCCACCTT CCTCTGAAGA GCTCGAGACT AACAAGGCCA CACTGGTGTG TA -#CGATCACT 420 - - GATTTCTACC CAGGTGTGGT GACAGTGGAC TGGAAGGTAG ATGGTACCCC TG -#TCACTCAG 480 - - GGTATGGAGA CAACCCAGCC TTCCAAACAG AGCAACAACA AGTACATGGC TA -#GCAGCTAC 540 - - CTGACCCTGA CAGCAAGAGC ATGGGAAAGG CATAGCAGTT ACAGCTGCCA GG -#TCACTCAT 600 - - GAAGGTCACA CTGTGGAGAA GAGTCTGTCT CGTGCTGACT GT - # - # 642 - - - - (2) INFORMATION FOR SEQ ID NO:5: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 10 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown - - (ii) MOLECULE TYPE: peptide - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: - - Glu Val Gln Leu Val Glu Ser Gly Ala Glu 1 5 - # 10 - - - - (2) INFORMATION FOR SEQ ID NO:6: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 10 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown - - (ii) MOLECULE TYPE: peptide - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: - - Asp Ile Lys Met Thr Gln Ser Pro Ser Ser 1 5 - # 10 - - - - (2) INFORMATION FOR SEQ ID NO:7: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 10 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown - - (ii) MOLECULE TYPE: peptide - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: - - Glu Val Gln Leu Val Glu Ser Gly Pro Gly 1 5 - # 10 - - - - (2) INFORMATION FOR SEQ ID NO:8: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 10 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown - - (ii) MOLECULE TYPE: peptide - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: - - Gln Ala Val Val Thr Gln Glu Ser Ala Leu 1 5 - # 10__________________________________________________________________________
The present invention relates to cDNAs encoding murine antibodies against apolipoprotein B-100, the protein moiety of low density lipoprotein(LDL) in human plasma. In addition, the present invention relates to the method of preparation of recombinant antibodies specific for human plasma apolipoprotein B-100 of LDL, and use thereof, for diagnosis and treatment of cardiovascular diseases.
8
BACKGROUND OF THE INVENTION [0001] The invention relates to a mechanical device designed to dissipate kinetic energy, such as (part of) the kinetic energy of a vehicle seat (in particular an aircraft passenger seat) and its occupant, when involved in a survivable accident or incident (such as an emergency landing of an aircraft). [0002] More particularly the invention relates to such a device which can be used in connection with vehicle seats provided with shoulder belts. [0003] The expression “vehicle seat” as used in the present text refers to seats that are appropriate for road or other surface transport vehicles and for air transport vehicles; the vehicle seats to which the invention most suitably applies are seats for public transport vehicles and aircrafts. [0004] Several energy absorbing systems for transport category aircraft seats have been proposed in the art. [0005] Most of the know systems are however designed to absorb the energy in the underframe structure of the seat. Reference can for instance be made in this respect to the following patent publications: DE 440 57 53, GB 2243540, U.S. Pat. No. 5,699,984, U.S. Pat. No. 5,069,505, U.S. Pat. No. 4,861,103. [0006] These known systems present serious drawbacks in view of the new standards for seats in transport category aircrafts issued in June 1998 by the U.S. Federal Aviation Administration (FAA) and the European Joint Aviation Authorities (JAA), to improve the chances of passenger survival in emergency landing. Essentially the new rules are contained in the FAR/JAR 25-561/562. Of utmost importance to the background of this Patent, is the section prescribing: 1. In § A and § B, the emergency landing conditions governing the design of the seat and restraint system supposed to protect the passengers. 2. In § C, a set of performance pass/fail criteria, related to the human body tolerance to impact loads, that must not be exceeded during the dynamic tests conducted in accordance with § A and § B of this section, in particular the Head Injury Criteria (HIC). [0009] The above set of criteria for seats design is well known by the air transport industry and aircrafts & seats manufacturers since June 1986. It appears however that the new performance standards prescribed in § C didn't receive appropriate attention. [0010] Most of the redesign effort was focused on the seat structure to comply with the § A and § B, leaving the protection of the occupants to a patchwork of partial measures for most of the requirements of § C, resulting in no solution regarding the HIC, with however the exception of an inflatable lap belt system, derived from the air-bag technology, associated to a conventional seat structure. [0011] According to the new rules, the former impact load required to be sustained by the seat structure, and its tie-down to the floor, was raised from a 9 g static load to a dynamic impact pulse triangularly shaped, peaking at 16 g. To meet that condition, most seat manufacturers developed various means to absorb part of the kinetic energy involved, in order to smooth off the peak of the 16 g pulse at a level acceptable by both the structure of the seat and its tie-down to the floor. [0012] This process has however its limitations: Because the space available between seat rows is limited, to protect the egress path of the passengers in emergency conditions, the maximum stroke allowed to the seat structure by any type of energy absorption device is limited to 3 inches by the airworthiness authorities. While this stroke might provide some smoothing off the peak dynamic pulse, it has practically no effect on the occupant excursion. Instead he will be allowed to pick-up speed relatively to the seat or the bulkhead in front, resulting in a secondary impact of the head which can be lethal. [0015] In view of this, one approach to meet the new requirements will probably involve the use of shoulder belt type passenger seats in transport category aircrafts. [0016] Only few energy absorption systems have been proposed which can affect the backrest of the seat and can therefore be used on such shoulder belt type passenger seats. [0017] Thus, for instance, U.S. Pat. No. 6,209,955, involving a deformable back seat structure, U.S. Pat. No. 5,676,421 proposing multiple fragmentation pins on the back seat, U.S. Pat. No. 5,320,308 proposing a structural “breakover” device in association with a friction brake or clutch arrangement on the seat back, or EP 0 651 957 proposing a back seat structure with damping structural parts. [0018] DE 19648974 proposes a rather complex energy absorption device, involving torsion bars and breakable connecting pieces, to be used on the underframe seat structure as well as at different levels of the back seat structure. [0019] U.S. Pat. No. 4,688,662 on the other hand describes an energy absorber system on the interconnection of the seat bottom frame and the seat back frame The system utilises a pair of housings having facing cavities and a hollow deformable torsion member interconnecting the housings. [0020] These state of the art energy absorption systems show several drawbacks with respect to the new criteria referred to above. [0021] It is the object of the present invention to provide an absorption device which meets the following objectives: 1. To restrain the passenger's body in the required dynamic conditions by means of a shoulder harness, single or double, featuring one or two attachments at the top of the frame of the backrest, in association with a lap belt, as currently used in automotive or other applications (such as aircraft applications), comprising rotation means allowing the backrest to break over when loaded forward by the shoulder belts, when the said loads exert a momentum exceeding a predetermined static resistance momentum on a specific part of the device. This component is working directly against the pivot axis of the backrest and is allowed a rotational, energy absorbing stroke, with the same angular amplitude than the backrest breakover, under constant application of the predetermined momentum; to extend this protection to scenarios of successive impacts including the full range of loading less than, and up to, the ultimate required in a variety of directions, while keeping the energy absorption capacity to smooth off the peak of the impact pulses at the predetermined and built-in value. [0025] To allow the return (or rebound) of the occupant to his initial raised up position after each impact breakover. 2. To perform all functions in normal use by the passengers and crew, in particular the control of the backrest recline as provided for in conventional seats. The backrest recline control device is characterised by its integration with the breakover control system, working on the same backrest axle, sharing the space available with the energy absorption system in the breakover mode. Functionally the two systems are independent and provisions are made to avoid any interference in the range of designed angular motions of the backrest, either in recline or in breakover. 3. To provide for easy selection of recline and break-over angular limitations, as required by the cabin layout, and current regulations. Specific means to select the range of angular motions are provided, for use by the maintenance crew. 4. To make use of conventional technology in the design & manufacturing. 5. To design for the lowest possible weight and production cost 6. To design for a minimum maintenance cost 7. To be compatible with a conventional seat configuration & its installation in a current, pressurised, transport category aircraft SUMMARY OF THE INVENTION [0033] The invention thus provides for a vehicle seat for equipment with shoulder belts connected to the seat backrest, comprising an energy absorbing device acting on the seat backrest, in which said energy absorbing device comprises deformable energy absorbing means ( 12 ), with at least one arcuate ( 13 , 14 ) area of plastically fragmentable material, opposing the rotation of said seat backrest ( 21 ) with respect to a lower seat structure ( 20 ) in one direction, corresponding to a forward-leaning movement of said seat backrest. [0034] The concept of deformable energy absorbing means comprising arcuate areas of plastically fragmentable material is known per se in the prior art, in connection with energy absorption on safety belt retractor means and/or retention means. Reference is made in this respect to prior art documents U.S. Pat. No. 5,639,806 and EP 1 000 822. [0035] According to a preferred embodiment of the invention, said deformable energy absorbing means preferably comprise [0000] at least one disc with at least one radially positioned arcuate area of plastically fragmentable material, and [0000] at least one stop plug acting upon said arcuate area of fragmentable material in said disc. [0036] According to a more preferred embodiment of the invention, said disc(s) comprise at least two radially positioned arcuate areas of plastically fragmentable material, and at least two corresponding stop plugs; most preferably the energy absorbing means comprise two discs and (or) two to four radially positioned arcuate areas of plastically fragmentable material, each extending over an angle of, for instance, 0,4 to 3 radiant (approximately 24-180°), and two to four corresponding stop plugs. Depending on the specific application the arcuate areas of plastically fragmentable material may however extend over a smaller angle (as from 0,1 radiant or less), or over a larger angle. [0037] The plastically fragmentable material of the arcuate fragmentation areas is preferably selected from aluminium, aluminium alloy 2024 T3, aluminium alloy AU4G1, or any other metal, synthetic or composite material having equivalent properties. [0038] A very specific embodiment of the invention may involve an energy absorbing device comprising a first part connected to the lower seat structure, respectively to the lower portion of the seat backrest, rotably interconnected with a second part connected to the lower portion of the seat backrest, respectively to the lower seat structure, via said deformable energy absorbing means, whereas the axis of rotation of said rotably interconnected first part and second part is positioned substantially along or in the vicinity of the hip joint axis in the profile of an average occupant. [0039] According to an interesting embodiment of the invention, releasable retention means may be provided between such first part ( 2 ) and such second part ( 4 ), allowing the rotation of said first part with respect to said second part means into the direction opposite to said one direction, corresponding to a backward-leaning direction of the seat backrest, without acting on said energy absorbing means, whereas the rotation of said first part with respect to said second part into said one direction is subjected to the reaction of said energy absorbing means. [0040] According to a preferred feature of this embodiment of the invention, said first part and said second part respectively constitute [0000] a support means of the lower seat structure, and [0041] a shaft connected to the lower portion of the seat backrest (or vice versa), whereas said releasable retention means preferably comprise a ratchet wheel mechanism providing fixed connection of said shaft with respect to said deformable energy absorbing means in said first direction, while providing free rotation of said shaft with respect to said deformable energy absorbing means in said opposite direction. [0042] Said shaft preferably comprises a grooved part interconnecting said shaft to a corresponding grooved aperture in said deformable energy absorbing means, said releasable retention means, said disc(s) with radially positioned arcuate area(s) of plastically fragmentable material and/or said ratchet wheel mechanism. [0043] According to a further feature of the invention, a separate conventional backrest recline control may in addition be integrated into said energy absorbing device, whereas said disc(s) with one or more area(s) of plastically fragmentable material further comprise one or more corresponding radially positioned arcuate open areas, allowing rotation of the disc(s) from a referenced position, defined with the backrest in upright position, into a direction opposite to the arcuate area of plastically fragmentable material. The slot width of said arcuate open area should suitably be slightly larger than the diameter of the stop plug to allow free rotation in the backward-leaning direction, without acting on the energy absorbing means nor making use of the releasable retention means. [0044] The seat preferably comprises one energy absorbing device at one side of the seat, whereas the seat backrest is interconnected, on the corresponding side of the seat, to said energy absorbing device via a grooved shaft, and, on the other side of the seat to the energy absorbing device of the adjacent seat or the seat structure, via a free rotating axle. [0045] The type of vehicle seats to which the invention most suitably applies is the group comprising surface transport vehicle seats, public transport vehicle seats and air transport vehicle seats. [0046] It has further been found that in the vehicle seat according to the invention, the axis of rotation of the backrest has preferably to be moved forward to avoid the bulk of the energy absorbing device protruding beyond the rear envelope of the seat. This position is different from the current position of the reclining axis on conventional seats which are mostly located in the vicinity of the backrest frame. [0047] Resulting from this position of the backrest rotation axis, to make provision for passenger comfort in the lower back area, the support axle is preferably split in two parts on the left and right side of the backrest frame, thus avoiding to install an axle crossing the full width of the backrest. This configuration leads to concentrate the momentum of the backrest to one side of the frame engaged through the axle of the energy absorbing device, the other side being a free rotation axle with no momentum capacity. This design decision, resulting in one energy absorbing unit per backrest, has proved to be the most economical in weight and cost, as well as compatible with the curved shape of a pressurised aircraft cabin, forbidding installation of an energy absorbing device on outboard seats in most seating layouts. [0048] One of the additional design objectives of the invention is to provide a backrest control device with a dual capability: In normal use, to control the recline at the choice of the passenger, In emergency use, to control the breakover by a preset energy absorbing device. 1. To save space and weight, the energy absorbing device according to the invention combines the two functions in one device as compact as possible, located under the armrest, working on the common axle in connection with the backrest frame. [0052] This offset position of the axle a positive effect on the safety and comfort of the passenger. [0053] Indeed, in this position, the axis of rotation of the backrest frame is closer to the natural body hip joint than in conventional seats. As a result, when reclining for comfort, or breaking-over for safety, the rotation of the upper torso matches closely the rotation of the backrest and avoids uncomfortable back friction in recline, while keeping the initial shoulder belt position in break-over conditions. [0054] As a further bonus, for maintenance purpose, it appears that the offset position of the backrest axle offers an easy access when dismounting the backrest from the seat main frame. To that end the axle of the backrest, featuring longitudinal grooves to transfer all momentum controlling the backrest angle, may allow, by axial motion, an easy disassembling of the backrest from the main seat frame. [0055] This feature is also partially used for allowing a full breakover when required by a stretcher installation. [0056] As the arcuate area, expected to absorb energy of a single impact, corresponds to the angular rotation of the back-rest during application of the impact loads, and as this rotation is limited to an angle matching the available striking distance ahead of the occupant, it results that the angular capacity of the arcuate area is from three to four times the capacity needed to absorb a single impact. [0057] The energy absorbing mechanism according to the invention can therefore be designed to use this redundant capacity to cope with successive impacts scenarios. [0058] Introducing a ratchet wheel in between the backrest and the discs supporting the arcuate area, allows the rebound of the backrest while keeping the disc in the position reached by the previous impact. [0059] Ipso facto, the return of the backrest to its initial upright position meets the requirement limiting the breakover, and/or permanent deformation, especially when the seat would be installed next to an emergency exit. [0060] This capacity to return to initial position and be available for a second or a third impact, is a distinctive advantage of the device according to the invention over the inflatable lap belt or any type of energy absorbing devices working on the seat structure. [0061] The axis of rotation of the seat backrest is therefore preferably positioned substantially along or in the vicinity of the hip joint axis in the profile of an average occupant (i.e. the men and woman 50% ile occupant, well known in the art). [0062] The energy absorbing device described above has a triple function in the vehicle seats according to the invention: absorption of the energy on the base structure of the seat; control of the headpath excursion of the head and upper body of the occupant reduction of the deceleration applied to the upper body part of the passenger. [0066] The invention also relates to an energy absorbing device, per se, designed to oppose the rotation of a first part with respect to a second part via deformable energy absorbing means with an arcuate area of plastically fragmentable material, wherein the energy absorbing device comprises releasable retention means subjecting every rotation of said first part with respect to said second part support means into said first direction to the reaction of said energy absorbing means, and allowing the rotation of said first part with respect to said second part into the direction opposite to said first direction, without acting on said energy absorbing means. [0067] According to a preferred embodiment of the energy absorbing device according to the invention, said deformable energy absorbing means comprise [0000] at least one disc with at least one radially positioned arcuate area of plastically fragmentable material, and [0000] at least one stop plug acting upon said arcuate area of fragmentable material in said disc. [0068] The disc(s) preferably comprise at least two radially positioned arcuate areas of plastically fragmentable material and at least two corresponding stop plugs; the energy absorbing means may for instance comprise two discs with each two to four radially positioned arcuate areas of plastically fragmentable material, each extending over an angle of 0,4 to 3 radiant, and two to four corresponding stop plugs. Depending on the specific application the arcuate areas of plastically fragmentable material may however extend over a smaller angle (as from 0,1 radiant or less), or over a larger angle. [0069] The plastically fragmentable material is preferably selected from aluminium, aluminium alloy 2024 T3, aluminium alloy AU4G1, or any other metal, synthetic or composite material having equivalent properties. [0070] According to another preferred feature of the energy absorbing device according to the invention, said first part and said second part constitute a support means and a shaft, whereas said releasable retention means comprise a ratchet wheel mechanism providing fixed connection of said shaft with respect to said deformable energy absorbing means in said first direction, while providing free rotation of said shaft with respect to said deformable energy absorbing means in said opposite direction. [0071] According to still another preferred feature of the invention, said shaft comprises a grooved part interconnecting said shaft to a corresponding grooved aperture in said deformable energy absorbing means, said releasable retention means, said disc(s) with radially positioned arcuate area(s) of plastically fragmentable material and/or said ratchet wheel mechanism. BRIEF DESCRIPTION OF THE DRAWINGS [0072] FIG. 1 A & 1 B: [0073] Isometric view of a typical assembly of a backrest and three point shoulder harness, mounted on a seat structure via a grooved shaft on one side and a free rotation axis on the opposite side. The grooved shaft is engaged in the energy absorbing device according to the invention. [0074] FIG. 2 : Isometric view of the energy absorbing device according to the invention. [0075] FIG. 3 : Exploded view of the energy absorbing device according to the invention. [0076] FIG. 4 : Side view of a disc assembly containing a disc, a ratchet wheel, 3 ratchets, ratchet axles and springs; the arcuate area divided in the energy absorbing semi circular path and the free recline slot, separated by the static stop plug [0077] FIG. 5 : Side view of a disc showing the configuration during the forward impact, when the disc rotate and the material of the arcuate area is fragmented by the static stop plug [0078] FIG. 6 : Isometric view describing the configuration of the discs components during the rebound phase after the forward initial impact [0079] FIG. 7 : Isometric view showing the configuration of the recline control sub-assembly during the backrest recline function DETAILED DESCRIPTION OF THE INVENTION [0080] The following is a detailed description of a preferred embodiment of the invention, as illustrated in the attached drawings. [0081] It will ompbe appreciated by anyone skilled in the art that many modifications and variations of the invention are possible in the light of the above teaching and within the boundaries of the appending claims, without departing from the general scope and spirit of the invention. [0082] The energy absorbing device according to this embodiment of the invention, for use on an aircraft passenger seat, involves: [0083] A casing (the support means referred to above), in the general shape of a flat cylinder containing the working parts of the energy absorbing function, including essentially a grooved shaft extending transversely in the adjacent backrest frame to engage in the internally grooved section of the adjacent backrest bracket, to form a rigid connection in torsion between the backrest frame and the energy absorbing device. Each casing is also rigidly fixed to the seat bottom frame. [0084] Inside the casing, the grooved shaft engages one disc (or wheel), featuring matching internal grooves, to the effect that the discs will be forced by the grooved shaft to follow all angular rotations, in recline or breakover of the backrest. [0085] At the periphery of the discs (or wheels), an arcuate path is provided in a semi circular shape about the shaft axis. In this path, the material is reduced in thickness to leave a relatively thin web featuring a limited strength, dedicated to absorb energy by material fragmenting process, when forced against a static stop plug inserted at a specific point perpendicular and through the disc in the arcuate provided area. [0086] The said static stop plug, mounted parallel to the shaft, is of such length as to extend through the casing at both ends after closure of the casing cover plates. [0087] In this position the plug will oppose a firm stop to the rotation of the disc in the direction and under impulse of the backrest breakover. [0088] In the opposite direction, corresponding to the backrest recline, the disc is free to rotate as the concerned area has been open to rotation by a curved arcuate slot whose width exceed the diameter of the static stop plug. The designed arc of the slot is such as to allow the maximum designed recline angle that the occupant of the seat might wish to adopt by use of a conventional control. [0089] The breakover area features a restriction to the disc, and the associated backrest, in the breakover rotation. This restriction could be a reduced width, smaller than the diameter of the static stop plug, or a web of limited thickness, or a combination of both, tuned to provide by the resistance of the stop plug, a semi circular path opposed to the rotation of the backrest up to a predetermined value of the breakover momentum. When this value is exceeded by the impacts conditions the disc start to rotate and absorb energy by material fragmenting. [0090] The energy absorbing system of this example in particular involves a plurality of discs mounted in parallel on a common shaft connected to one individual backrest. [0091] They are similarly provided in the arcuate area, to propose each a free slot for backrest recline and a reduced thickness slot for energy absorption by material fragmenting process. The stop plug is installed the same way, through all discs and the casing static support, to perform the same stopping function. [0092] The energy absorbing system of the example in particular also comprises two static plugs mounted in parallel with the shaft, positioned diametrically opposed in the arcuate area and sharing equally the available arcs dedicated for clearing the recline on one side and absorb the energy, on the other side, as required by the operational and or impact conditions. [0093] The energy absorbing system according to this example furthermore comprises a ratchet wheel, installed between the shaft and each one of the discs, so that the torque applied by the breakover of the backrest is transmitted to the discs by a set of spring loaded ratchets. [0094] In the energy absorbing system according to the example, the dimensions of the “forced slots” in the breakover area of the discs, are such that, after an impact, the discs will be retained by jamming on the static plugs in the position reached at the end of the impact pulse. In this situation, the ratchet wheels will enable the backrest to return to its initial upright position, and the system will be ready to perform the same function of energy absorption, starting from the new position of the discs. [0095] In the energy absorption system according to the example, the total arc provided for energy absorption, has a capacity to absorb a succession of breakover impacts amounting, for example, to three impacts using each an average arc of 30°, up to a total of 90° arc. [0096] The energy absorption system according to the example, comprises two discs, mounted in parallel on the common shaft, allowing installation of a recline control lever in between, in selective association with the common shaft, to allow control of the recline of the backrest by the occupant of the seat. The selective association is meant to control the recline only while leaving the possibility for backrest breakover without the angular limitations of a conventional recline system. [0097] In the following description, any element identified by a number in one drawing will represent the same element in any other drawing. The following is a list of the major working elements: [0000] Energy absorbing device assembly ( 1 ) [0000] Casing ( 2 ) [0000] Casing cover ( 3 ) [0000] Grooved shaft ( 4 ) [0000] Free rotation axle ( 5 ) [0000] Disc (or discs) chamber ( 6 ) [0000] Recline control sub-assy ( 7 ) [0000] Recline lever ( 8 ) [0000] Recline transmission wheel ( 9 ) [0000] Breakover control sub-assy ( 10 ) [0000] Disc sub-assy ( 11 ) [0000] Disc frame & arcuate area ( 12 ) [0000] Disc arcuate energy absorbing section ( 13 ) [0000] Disc arcuate material area fragmented during impact ( 14 ) [0000] Disc arcuate recline slot section ( 15 ) [0000] Ratchet wheel ( 16 ) [0000] Ratchets & axles ( 17 ) [0000] Ratchet springs & axles ( 18 ) [0000] Static stop plug ( 19 ) [0000] Seat primary structure ( 20 ) [0000] Backrest structure assembly ( 21 ) [0000] Backrest controlled rotation bracket ( 22 ) [0000] Backrest free rotation bracket ( 23 ) [0000] Shoulder harness assembly ( 24 ) [0000] Diagonal shoulder belt ( 25 ) [0000] Casing opening for recline lever ( 26 ) [0000] Lug (casing internal extension) ( 27 ) [0000] Angular gaps in recline control assembly ( 28 ) [0000] Grooved shaft lateral stop cover ( 29 ) [0098] For the convenience of description, a forward direction and a rearward direction are defined by corresponding arrows relative to the perspective of a person sitting normally in passenger seat. [0099] The device ( 1 ) is a mechanical rotative energy absorbing device, designed to dissipate part of the kinetic energy of the occupant of a passenger's seat, in a Transport Category Aircraft, when decelerated in a forward dynamic impact. [0100] The device is fixed to the seat primary structure ( 20 ) and works in association with a backrest structure ( 21 ) on which a shoulder belt ( 25 ), is attached. [0101] The shoulder belt ( 25 ) is associated with a lap belt ( 26 ) as parts of a three point shoulder harness assy ( 24 ) (ref. to FIG. 1 ). [0102] The device controls the use, as a stopping distance, of the space available for breakover in front of the occupant, to the effect that the occupant head path in the direction of forward inertial load will be reduced and to avoid any lethal contact with any aircraft interior partition or seat in front, or any other interior feature. [0103] The device is working, via the grooved shaft ( 4 ), through the structure of the backrest ( 21 ) and the shoulder belt ( 25 ), in opposition to any forward motion of the upper torso of the occupant, and will limit the loads applied to the mass of the upper torso within acceptable human body tolerance, considering the energy level involved, and will also limit the loads in the lower seat structure ( 20 ), including the tie-down to the aircraft floor and the aircraft floor itself, within allowable values. [0104] The backrest structure is also pivotally connected by a free rotation bracket ( 23 ) to the free rotation axle ( 5 ) on the side opposite to the device (ref. to FIG. 2 ). [0105] The energy absorbing function is performed in a break-over control sub-assy ( 11 ) making use of a “fragmented material process” designed to produce an initial predetermined locking momentum on the grooved shaft ( 4 ) of the backrest bracket ( 22 ), therefore opposed to the backrest rotation up to a predetermined level, followed by a continuous braking momentum at a slightly superior level. [0106] The energy absorbing device (ref. to FIG. 3 ) is characterised by a casing ( 2 ), in the general shape of a flat cylinder containing in the disc chamber ( 6 ) the working parts of the energy absorbing function, including essentially a grooved shaft ( 4 ) extending transversely in the adjacent backrest frame to engage in the internally grooved section of the adjacent backrest bracket ( 22 ), to form a rigid connection in torsion between the backrest frame ( 21 ) and the energy absorbing device ( 1 ). The grooved shaft ( 4 ) is fixed laterally to the grooved backrest bracket ( 22 ) by a stop cover ( 29 ). [0107] The casing ( 2 ) is also rigidly fixed to the seat primary structure ( 20 ). [0108] Inside the casing, the grooved shaft ( 4 ) engages, via a ratchet wheel system ( 16 ) featuring internal grooves and associated set of minimum three ratchets spring loaded ( 18 ) pivotally connected to the disc frames ( 12 ) in one or several discs sub-assy ( 11 ), to the effect that the discs sub-assy ( 11 ) will be forced by the grooved shaft to follow all rotations of the backrest in recline or breakover, with the exception of the rebound post-impact. [0109] At the periphery of the discs sub-assy ( 11 ), an arcuate area ( 12 ) is provided in a semi circular ring about the shaft axis. This area is divided in two sections: One section ( 13 ) is in charge of the energy absorbing function. In this section, the material is reduced in thickness to leave a relatively thin web featuring a limited strength, designed to absorb energy by material fragmenting process, when forced against a static stop plug ( 19 ) inserted at a specific point perpendicular and through the disc in the arcuate provided area ( 12 ) (ref. to FIG. 5 ). [0110] In the preferred embodiment, for a better balance of the momentum loads, two static stop plugs ( 19 ) are mounted in parallel to the shaft ( 4 ), diametrically opposed, through the arcuate area and sharing equally the available arcs dedicated for clearing the recline on one way and absorb the energy, on the other way, as required by the operational and or impact conditions. [0111] The said static stop plugs ( 19 ), mounted parallel to the shaft, are of such length as to extend through the casing, through any lug ( 27 ) or casing internal extension provided in between the discs and at both ends in the casing cover plates ( 3 ). [0112] In this position the plugs will oppose a firm stop to the rotation of the disc sub-assy ( 11 ) in the direction and under impulse of the backrest breakover and will transfer any breakover momentum to the casing ( 2 ) and to the seat primary structure ( 20 ). [0113] The arcuate area ( 13 ) opposes a restriction to the disc, and the associated backrest, to the breakover rotation. This restriction could result from a reduced width, smaller than the diameter of the static stop plug ( 19 ), or a web of limited thickness, or a combination of both, tuned to provide against the resistance of the stop plug, a semi circular path opposed to the rotation of the backrest up to a predetermined value of the breakover momentum. When this value is exceeded by the impacts conditions the disc start to rotate and absorb energy by material fragmenting. [0114] A ratchet wheel ( 16 ) is installed between the shaft and each one of the discs, so that the torque applied by the breakover of the backrest is transmitted to the discs by a set of spring loaded ratchets ( 17 ) (ref. to FIG. 4 ). This one-way momentum transmission allows the return of the backrest close to its initial pre-impact position, to meet the requirements regarding the allowable post-impact seat structure deformation. [0115] The device is also designed to perform its energy absorbing function in response to successive impacts, as might be expected in a survivable emergency landing scenario, by allowing, after each impact, the return of the occupant to his initial upright position and offering adequate capacity for further energy absorbing strokes. [0116] Indeed the arcuate area ( 13 ), expected to absorb energy of a single impact, corresponds to the angular rotation, or breakover, of the backrest during application of a single impact load, and as this rotation is, by the seat installation criteria in an aircraft, limited to an angle matching the available stopping distance in front of the occupant (about 25°), it may be observed that the angular capacity of the arcuate area being 120° is from three to four times the capacity needed to absorb a single impact at the highest designed level (16G forward). [0117] This being a direct advantage resulting from the internal geometry of the device, that is, the compact semi circular shape of the arcuate area ( 13 ), the device mechanism is designed with the means to use this redundant capacity to cope with successive impacts scenarios. [0118] By making use of the ratchet wheels ( 16 ) (provided in between the shaft ( 4 ) of the backrest and the discs sub-assy ( 11 ) supporting the arcuate area ( 12 ) to allow the rebound of the backrest), it is provided in the detail design of the arcuate area ( 13 ) the possibility to keep the discs sub-assy ( 11 ) in the position reached under the previous impact (ref. to FIG. 6 ). [0119] To that end, the dimensions of the forced slots in the breakover area of the discs ( 14 ), are such that, after an impact, the discs will be retained by jamming on the static plugs in the position reached at the end of the impact pulse. In this situation, the ratchet wheels will enable the backrest to return to its initial upright position, and the system will be ready to perform the same function of energy absorption, starting from the new position of the discs. [0120] This capacity to return to initial position and be available for a second or a third impact, is a distinctive advantage of the device over the inflatable lap belt or any type of energy absorbing devices working on the seat structure [0121] Besides, designing the arcuate energy absorption section to limit the stroke to about 25° under a 16 g impact is a challenging design objective in consideration of the occupant tolerance and the seat structural limitations. The experience has shown that the margin of success on this criteria is very narrow but not out of reach to those familiar with the art to which this invention relates. [0122] There is also a dual capability of the backrest control device. Due to the particular configuration of the backrest pivot point, it was soon determined that one of the design objective of the invention should be to provide a backrest control device with a dual capability: in normal flight conditions, to control the recline at the choice of the passenger; in emergency conditions, to control the breakover by a pre-set energy absorbing device; [0125] To save space and weight, it was decided to combine the two functions in one assembly ( 1 ), as compact as possible, located under the armrest, working on the common shaft in connection with the backrest frame. [0126] The assembly ( 1 ) integrates the means to allow the occupant of the seat to control the recline of his backrest. [0127] The backrest linear recline control device ( 19 ) is characterised by its integration with the breakover control system, working on the same backrest shaft ( 4 ) sharing the space available in the disc chamber ( 6 ) with the energy absorption system [0128] Functionally the two systems are independent and provisions are made to avoid any interference in the range of designed angular motions of the backrest, either in recline or in breakover. [0129] They are similarly provided in the arcuate area ( 22 ), to propose each a free arcuate recline slot section ( 15 ) for backrest recline opposite to the energy absorbing section ( 13 ). The stop plugs ( 19 ) are installed the same way, through all discs and the casing static support, to perform the same stopping function in the upright position of the backrest. [0130] The two discs are mounted in parallel on the common shaft ( 4 ), allowing installation of a recline control lever ( 8 ) in between, in selective association with the common shaft, to allow control of the recline of the backrest by the occupant of the seat. The selective association is meant to control the recline only while leaving the possibility for backrest breakover without the angular limitations of a conventional recline system. This is achieved by installation of a selective transmission wheel ( 9 ) in between the shaft and the recline lever ( 8 ). Angular gaps ( 28 ) are provided between the wheel ( 9 ) and the lever ( 8 ), allowing the necessary breakover as required by the energy absorbing function without interference (ref. to FIG. 7 ). [0131] For the same purpose, In the opposite direction, corresponding to the backrest recline, the discs sub-assy ( 11 ) are free to rotate as the concerned area has been opened to rotation by the arcuate recline slot ( 15 ) whose width exceed the diameter of the static stop plug ( 19 ). The designed arc of the slot is such as to allow the maximum designed recline angle that the occupant of the seat might wish to adopt by use of a conventional linear control. [0132] While specific embodiments and applications of this invention have been shown and described, it should be clear to those skilled in the art that many more modifications and applications are possible without departing from the inventive concepts herein. [0133] Thus, whereas the invention has been illustrated specifically referring to aircraft seats, it must be stressed that the invention is also particularly suited for any type of surface or air transport vehicle, and in particular for any type of public transport vehicle. [0134] The invention is, therefore, not to be restricted in any way, except in the spirit of the appended claims.
The invention relates to a vehicle seat for equipment with shoulder belts ( 24 ) connected to the seat backrest ( 21 ), comprising an energy absorbing device ( 1 ) acting on the seat backrest, wherein said energy absorbing device comprises deformable energy absorbing means ( 12 ), with at least one arcuate ( 13, 14 ) area of plastically fragmentable material, opposing the rotation of said seat backrest ( 21 ) with respect to a lower seat structure ( 20 ) in a first direction, corresponding to a forward-leaning movement of said seat backrest. The invention also relates to energy absorbing devices opposing the rotation of a first part ( 1 ) with respect to a second part ( 2 ) via deformable energy absorbing means ( 12 ) with an arcuate area ( 13, 14 ) of plastically fragmentable material, wherein the energy absorbing device comprises releasable retention means ( 16 ) subjecting every rotation of said first part with respect to said second part into a first direction to the reaction of said energy absorbing means and allowing the rotation of said first part with respect to said second part, into the direction opposite to said first direction, without acting on said energy absorbing means.
1
This is a continuation-in-part of copending application Ser. No. 07/663,604 filed on Mar. 4, 1991 now U.S. Pat. No. 5,206,116. BACKGROUND OF THE INVENTION 1. Introduction This invention relates to light-sensitive compositions. More particularly, this invention relates to aqueous developable light-sensitive compositions useful as high resolution soldermasks in the manufacture of printed circuit boards. 2. Description of the Prior Art Aqueous developable liquid soldermasks are known. They are typically applied as a wet coating, such as by curtain coating, dried, image-wise exposed to activating radiation, partially cured using heat, developed, such as with an aqueous alkaline solution, and often finally cured. Examples of aqueous developable soldermasks are disclosed in European patent Publication No. 0,255,989 and in Japanese published Patent Disclosures 55-129341 and 60-26943 published Oct. 7, 1980 and Feb. 9, 1985, respectively. Soldermasks disclosed in these publications typically consist of at least one alkali soluble phenolic resin, a compound containing at least two epoxy or vinyl ether groups, generally an epoxy resin, and a photoactive component such as a sulfonium salt or an azide compound capable of initiating crosslinking of the epoxy or vinyl ether compound upon exposure to activating radiation with heating as necessary. The phenolic component, in adequate concentration, enables aqueous development, and the combination of the epoxy or vinyl ether compound and the photoactive component permits cure in exposed areas of the film. In use, image-wise exposure of a dry film of the above composition to activating radiation initiates a photoreaction, such as the liberation of an acid. The acid catalyzes crosslinking of the epoxy or vinyl ether component of the formulation in imaged areas where the photoreaction occurs. Selective curing results in areas of differential solubility that permit development of the soldermask film. It has been found that the aqueous developable soldermasks, as disclosed in the referenced publications, fail to yield a high resolution image upon development. It is believed that a cause of poor resolution is the phenolic component of the formulation. Prior to development, the phenolic component is essentially uncured because the liberation of acid by the photoreaction does not catalyze curing of the phenolic component of the soldermask. Consequently, upon contact of an exposed film with developer, selective development is possible between exposed and non-exposed areas because the epoxy or vinyl ether component is cured, but high resolution images are not obtained because the phenolic component is non-selectively dissolved from both exposed and non-exposed portions of the coating alike. In EPO application publication No. 0,255,989 referenced above, it is disclosed that a thermal curing agent for the phenolic component may be included in the formulation. However, if included, the phenolic of the composition cannot be cured prior to development because curing will take place uniformly in both exposed and non-exposed portions of the film making development difficult or impossible. Therefore, inclusion of a thermal curing agent would not overcome the problem of poor resolution following development. SUMMARY OF THE INVENTION The photoimageable composition of the invention comprises a binder that is a mixture comprising an alkali soluble phenolic resin and a compound containing at least two active groups selected from epoxy groups, vinyl ether groups and mixtures of the two, a photoactive compound that liberates a curing catalyst for binder components in imaged areas upon patterned exposure to activating radiation, and a crosslinking agent for the phenolic resin component of the binder that is activated in the presence of a photogenerated curing catalyst. In a preferred embodiment of the invention, the primary components of the binder comprise a poly(vinyl phenol) and an epoxy resin. The composition of the invention is used in conventional manner. It is applied to a substrate, dried, exposed to patterned radiation at a wavelength that causes a photoreaction that liberates a curing catalyst, heated as necessary to cure the film in exposed areas, developed and optionally heat cured. In accordance with the invention, all primary components of the binder, inclusive of the phenolic component, are cured in imaged areas, but not elsewhere. Therefore, upon development, high resolution images are obtained because uncured binder is essentially not solvated in the exposed areas of the film. Following development, a post development bake step may be employed to complete the curing reactions. DESCRIPTION OF THE DRAWING The drawing is a diagrammatic representation of comparative processes and results using a photoactivated curing agent for all polymer components in accordance with the invention compared to results that would be obtained using a non-photoactivated curing agent for the binder components. More specifically, in the drawings, FIG. 1 illustrates a substrate coated with a solder mask coating; FIG. 2 represents the article of FIG. 1 following exposure to activating radiation; FIG. 3A represents the exposed article of FIG. 2 following heat curing. FIG. 4A represents the article of FIG. 3A following development, and FIG. 5A represents the article of FIG. 4A following subsequent curing. For purposes of comparison with the prior art, FIG. 3B represents the article of FIG. 2 where all components of the solder mask are cured; and FIG. 4B represents the article of FIG. 3B following attempted development of the same. DESCRIPTION OF THE PREFERRED EMBODIMENTS The phenolic resin component of the composition of the invention is a film-forming resin having phenolic hydroxyl groups that permit development of the composition in an aqueous alkaline developer. Phenolic resins are well known in the art. Exemplary phenolic resins include, for example, phenol aldehyde condensates known as the novolak resins, homo and copolymers of alkenyl phenols and homo and copolymers of N-hydroxyphenylmaleimides. The novolak resins are preferred. They are made following procedures known in the art and disclosed in numerous publications such as by DeForest, Photoresist Materials and Processes, McGraw-Hill Book Company, New York, Ch. 2, 1975 and by Moreau, Semiconductor Lithography Principles, Practices and Materials, Plenum Press, New York, Chs. 2 and 4, 1988, both incorporated herein by reference. Novolak resins are the thermoplastic condensation product of a phenol and an aldehyde. Examples of suitable phenols for condensation with an aldehyde, especially formaldehyde, for the formation of novolak resins, include phenol; m-cresol; o-cresol; p-cresol; 2,4-xylenol; 2,5-xylenol; 3,4-xylenol; 3,5-xylenol; thymol and mixtures thereof. An acid catalyzed condensation reaction results in the formation of a suitable novolak resin which may vary in molecular weight from about 500 to 100,000 daltons. The preferred novolak resins are the cresol formaldehyde condensation products. Poly(vinyl phenol) resins may be formed by block polymerization, emulsion polymerization or solution polymerization of corresponding monomers in the presence of a suitable catalyst. Suitable materials, for purposes of the invention, include those materials disclosed in EPO application publication No. 0,255,989 and in U.S. Pat. No. 4,439,516 incorporated herein by reference. An additional, though lesser preferred class of phenolic resins for purposes of the present invention, include homo and copolymers of N-hydroxyphenyl maleimides. Such materials are also disclosed in the above-cited European published application 0,255,989 beginning on page 2, line 45 and continuing to page 5, line 51, incorporated herein by reference for its teaching of such resins. Included within the scope of the term "phenolic resin" as used herein are the copolymers of cyclic alcohols and phenols as disclosed in published European patent application No. 0 401 499 having a publication date of Dec. 12, 1990 and incorporated herein by reference. Another component of the composition of the invention is one containing at least two active groups selected from epoxy groups, vinyl ether groups and mixtures of the two. Useful epoxy-containing materials are disclosed in the above referenced EPO application publication No. 0,255,989. They may vary from low molecular weight monomeric materials to high molecular weight polymers and may vary greatly in the nature of their backbone and substituent groups. The backbone may be of any type and substituent groups may be any group free of an active hydrogen atom reactive with an oxirane ring at room temperature. Illustrative of suitable substituents include halogens, ester groups, ethers, sulfonate groups, siloxane groups, nitro groups, phosphate groups, etc. Exemplary epoxy-containing materials include glycidyl ethers such as the glycidyl ethers of polyhydric phenols obtained by reacting a polyhydric phenol with an excess of chlorohydrin such as epichlorohydrin. Further examples of epoxy materials of this type are described in U.S. Pat. 3,018,262, incorporated herein by reference. There are many commercially available epoxy materials suitable for use in the compositions of the invention. Such materials include epichlorohydrin, glycidol, glycidylmethacrylate, the glycidyl ether of p-tertiarybutylphenol (e.g. those available under the trade designation "Epi-Rez" 5014 from Celanese); diglycidyl ether of Bisphenol-A (e.g. those available under the trade designations "Epon 828," "Epon 1004" and "Epon 1010" from Shell Chemical Co. and "DER-331," "DER-332" and "DER-334," from Dow Chemical Co.), vinylcyclohexene dioxide (e.g. "ERL-4206" from Union Carbide Corp.), 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexene carboxylate (e.g. "ERL-4201" from Union Carbide Corp.), bis(2,3-epoxy-cyclopentyl) ether (e.g. "ERL-0400" from Union Carbide Corp.), aliphatic epoxy modified with polypropylene glycol (e.g. "ERL-4050" and "ERL-4052" from Union Carbide Corp.), epoxidized polybutadiene (e.g. "Oxiron 2001" from FMC Corp.), flame retardant epoxy resins (e.g. "DER-580," a brominated bisphenol type epoxy resin available from Dow Chemical Co.), 1,4-butanediol diglycidyl ether of phenol formaldehyde novolak (e.g. "DEN-431" and "DEN-438" from Dow Chemical co.), and resorcinol diglycidyl ether (e.g. "Kopoxite" from Koppers Company, Inc.). Examples of compounds with at least two vinyl ether groups include divinyl ethers of aliphatic, cycloaliphatic, aromatic or araliphatic diols. Examples of such materials include divinyl ethers of aliphatic diols having from 1 to 12 carbon atoms, polyethylene glycols, propylene glycols, polybutylene glycols, dimethylcyclohexanes, etc. Specific examples include divinyl ethers of ethylene glycol, trimethylene-1,3-diol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, resorcinol, Bisphenol-A, etc. The photoactive compound used in the composition of the invention is one that liberates a photogenerated curing catalyst upon exposure to activating radiation. Preferably, the catalyst is an acid. The photogenerated curing catalyst initiates the reactions that cause cure of the binder components in the presence of curing agents, as necessary. Since the curing reactions are dependent upon a photogenerated catalyst, curing takes place only in exposed areas of a coating formed from the composition. Since all primary components of the binder are cured in the exposed coating, differential solubility between exposed areas and unexposed areas is excellent resulting in developed images of high resolution without significant loss of binder from exposed areas. As stated above, preferred photoactive components of the invention are photoacid generators. Photoacid generators useful in the compositions of the invention are known in the art and extensively described in the literature such as in U.S. Pat. Nos. 4,090,936 and 5,034,304 incorporated herein by reference. One class of preferred acid generators are onium salts of a Group VA element, onium salts of a Group VI A element, and aromatic halonium salts. These complex salts, upon being exposed to activating radiation such as ultraviolet radiation or electron beam irradiation, generate acids capable of initiating the required reactions. Preferred onium photoactive compounds are aromatic iodonium complex salts and aromatic sulfonium complex salts. These materials are fully disclosed in the above noted published EPO application No. 0,255,989. Examples of aromatic iodonium complex salt photoactive compounds include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, phenyl-2-thienyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di(2,4-dichlorophenyl)iodonium hexafluorophosphate, di(4-methoxyphenyl)iodonium hexafluorophosphate and di(3-methoxycarbonylphenyl)iodonium hexafluorophosphate, di(4-acetamidophenyl)iodonium hexafluorophosphate. Examples of aromatic sulfonium compounds include triphenylsulfonium tetrafluoroborate, dimethylphenylsulfonium hexafluorophosphate, tritolysulfonium hexafluorophosphate, 4-butoxyphenyldiphenylsulfonium tetrafluoroborate, tris(4-phenoxyphenyl)sulfonium hexafluorophosphate, 4-acetoxy-phenyldiphenylsulfonium tetrafluoroborate, tris(4-thiomethoxyphenyl)sulfonium hexafluorophosphate, di(methoxynaphthyl)methylsulfonium tetrafluoroborate, dimethylnaphthylsulfonium hexafluorophosphate and phenylmethylbenxylsulfonium hexafluorophosphate. Of the aromatic sulfonium complex salts which are suitable for use in the compositions of the invention, triaryl substituted salts such as triphenylsulfonium hexafluorophosphate are preferred. Another class of photoactive compounds suitable for purposes of the present invention are the photoacid generators such as those disclosed in U.S. Pat. No. 5,034,304. In particular, halogenated photoacid generators are preferred. These materials include 1,10-dibromodecane; 1,1-bis[p-chlorophenyl]-2,2-di-dichloroethane; 4,4 1 -dichloro-2-(trichloromethyl) benzhydrol or 1,1-bis(chlorophenyl)2-2,2-trichloroethane (Kelthane®); hexachlorodimethyl sulfone; 2-chloro-6-(trichloromethyl) pyridine; 0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl)phosporothionate (Dursban®); 1,2,3,4,5,6-hexachlorocyclohexane; N(1,1-bis [p-chlorophenyl]-2,2,2-trichoroethyl acetamide; tris [2,3-dibromopropyl] isocyanurate; 2,2-bis [p-chlorophenyl]-1,1-dichloroethylene; and their isomers, analogs, homologs, and residual compounds. Most preferred of the aforesaid is tris [2,3-dibromopropyl] isocyanurate. An additional component of the composition of this invention is a low temperature curing agent for the phenolic component of the binder catalyzed by photogenerated catalyst. Preferred curing agents are acid catalyzed materials reactive with the phenolic hydroxyl group. An especially preferred agent is a melamine formaldehyde resin. Melamine formaldehyde resins are amino resins formed by condensation of formaldehyde with melamine. The resins are typically ethers such as trialkylol melamine and hexaalkylol melamine. The alkyl group may have from 1 to as many as 8 or more carbon atoms but is preferably methyl. Dependent upon the reaction conditions and the concentration of formaldehyde, the methyl ethers may react with each other to form more complex units. Melamine resins are known in the art, commercially available from American Cyanamid Company of Wayne, N.J. under the trade name Cymel and described in American Cyanamid's product bulletin High Solids Amino Crosslinking Agents, published in 1984 as Bulletin No. 4-2111 5K7/84. In accordance with this invention, the preferred melamine formaldehyde resin has a degree of polymerization varying between 1.3 and 2.0 and most I preferably, is a member of the Cymel 300 Resin series which are highly methylated melamine formaldehyde resins. The most preferred melamine formaldehyde resin for purposes of this invention is Cymel 301 which is a hexamethoxymethyl melamine with a low methylol content having alkoxy groups as the principle reactive groups and a degree of polymerization of 1.5. The preferred catalyzed crosslinking agents are believed to react primarily with the phenolic resin. Consequently, it is believed that the following exposure and low temperature cure and prior to development, the photoimaged composition in exposed portions of the film comprise a network consisting primarily of epoxy condensation products and the reaction product of the phenolic resin and the melamine resin. Other conventional additives may be included in the compositions of the invention such as dyes, fillers, wetting agents, fire retardants and the like. Sensitizers constitute a preferred additive and are added to increase the range of wavelength photosensitivity. Suitable sensitizers include phenothiazines inclusive of substituted phenothiazines, 2-ethyl-9,10-dimethoxy-anthracene, 9,10-dichloroanthracene, 9,10-phenylanthracene, 1-chloroanthracene, 2-methylanthracene, 9-methylanthracene, 2-t-butyl anthracene, anthracene, 1,2-benzanthracene, 1,2,3,4-dibenzanthracene, 1,2,5,6-dibenzanthracene, 1,2,7,8-dibenzanthracene, 9,10-dimethoxydimethylanthracene, and the like. To formulate the composition of the invention, components are dissolved in a suitable solvent such as, for example, one or more glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether; esters such as a methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate and other solvents such as dibasic esters, propylene carbonate and gamma-butyro lactone. The concentration of composition components may vary within wide limits dependent upon the use of the material. Concentration ranges for the principal ingredients of the formulation are set forth in the following table and expressed as dry solids in parts by weight. ______________________________________ Broad Range Preferred Range______________________________________Phenolic Resin 25-65 40-50Epoxy or Vinyl ether 15-50 25-35CompoundCrosslinking Agent 5-35 1-20Photoactive Compound 1-15 2-10______________________________________ In addition to the above components, other additives commonly found in such compositions, such as those described above, are present in minor concentration except for fillers and pigments which may be present in larger concentration such as, for example, in amounts of from 5 to 30 percent by weight of the total of the dry components. The above components are desirably dispersed in a solvent to form a liquid coating composition. Their concentration in a solvent would depend on several factors, for example, the coating method used to apply the material to a substrate. For example, the concentration of the dry components in a slot coating composition would be higher than in a curtain coating composition. In general, the concentration of the dry components in the solvent may vary from about 10 to 50 weight percent or more of the total weight of the coating composition. For example, for a curtain coating composition, the percentage may vary between about 20 and 30 percent of the total concentration, and for slot coating may vary between 40 and 50 percent, it being understood that the weight percentage of solids in the composition would be best determined by the viscosity required for the particular coating method used. If the composition is to be applied as a dry film, of course the dry film would be essentially free of solvent. The coating composition of the invention is used in conventional manner provided there is a step of low temperature cure following exposure and preceding development. Using a method for forming a printed circuit board for purposes of exemplification, the photoimageable composition may be applied to a substrate having a pattern of conductive material disposed thereon. The substrate may be a copper laminate substrate prepared by the method described in the second chapter of Printed Circuits Handbook by Clyde F. Coombs, Jr., 2nd Edition, McGraw-Hill, 1979. Other suitable substrates include those prepared by laminating multilayer boards for the manufacture of printed circuit boards with vias (through-holes) and interconnections which may contain solder, as described in chapter twenty-three of the above reference, both incorporated herein by reference. The composition of the invention is coated onto the substrate using conventional techniques and preferably, the coating is deposited so as to yield a dry film thickness of at least 0.50 mil on top of a trace as required by IPC Specification No. SM-840B. After coating, the wet film formed is dried at a temperature varying between about 80° and 100° C. for a time of from about 20 to 60 minutes to remove solvent. During this drying step, it is desirable to avoid temperatures in excess of 120° C. and drying times of more than 60 minutes to prevent premature curing of the composition as this could make development difficult. The process of transferring an image to the coating involves exposing the coating to a source of patterned activating radiation to initiate the photoreaction in exposed areas. Suitable sources of activating radiation include actinic radiation, x-rays, etc. Following exposure, the layer is subjected to a low temperature bake to initiate crosslinking of the exposed portions of the binder by the liberation of the photogenerated catalyst. The bake conditions comprise heating to a temperature capable of initiating the curing reaction but the temperature should be below that temperature where thermal crosslinking would occur in unexposed areas of the film. Preferably, the bake temperature varies between about 85° to 120° C. and the bake time ranges between 1 and 20 minutes. During this step, catalyst generated by the photoreaction initiates the curing reaction of the binder components in exposed areas of the film. Following the above procedure, the area not exposed to activating radiation which is free of photogenerated, catalyst remains uncured and is readily dissolved by aqueous alkali solutions such as sodium hydroxide, sodium metasilicate, sodium carbonate, potassium hydroxide, potassium carbonate, ethylene diamine and the like. The preferred developer is a metal hydroxide with concentrations between 0.5 to 5% of alkaline hydroxide in water. A typical development time is 30 to 60 seconds. After development of the image, the remainder of the coating is characterized by a partial cure whereby most of the binder components are crosslinked. A second cure is desirable to achieve full thermal and electrical solder mask properties. This may be achieved by heating to a temperature of about 120° to 160° C. for a period of time of between about 10 and 60 minutes. The second cure hardens the developed image and the coating is resistant to soldering and may also be used as a permanent dielectric coating. The above process is depicted in the drawing, Sequence A, where in FIG. 1, substrate 1 is coated with soldermask coating 2. Exposure of soldermask coating 2 in FIG. 2, using a photoacid generator for purposes of illustration, results in a region 3 of the coating having photogenerated acid in exposed areas as represented by the symbol H + . Thereafter, as shown by FIG. 3A, following low temperature cure, coating 2 is cured in region 3 to crosslink the exposed areas of the coating. Following cure, the coating is developed to remove unexposed areas of the coating with exposed and cured region 3 remaining due to decreased solubility in the developer following cure. This is illustrated by FIG. 4A of the drawing. Finally, following full cure, as shown in FIG. 5A, the crosslinking density in region 3 is significantly increased. By comparison, with reference to Sequence 2, if an attempt is made to cure all components of the binder of coating 2 in the absence of a catalyzed crosslinking agent, the result would be a coating 3 where all portions of the coating would be insoluble in developer as shown in FIG. 3B and 4B where in FIG. 3A, high temperature cure is used and in FIG. 4B, development is unsuccessfully attempted. The following examples illustrate the invention. EXAMPLES 1 TO 9 The following compositions were prepared by customary mixing procedures where the phenolic resin used is poly(p-vinylphenol) (PVP); the epoxy resin is a bisphenol-A epoxy; the melamine is hexamethoxymethyl melamine; the photoinitiator (PI) is triphenylsulfonium tetrafluoroantimonate; and the solvents are 100% propylene glycol monomethyl ether acetate (S) or a cosolvent of 50% propylene glycol monomethyl ether acetate and 50% dipropylene glycol monomethyl ether acetate (Co). The concentration of each component for each example is as set forth in the following table. ______________________________________Ex-ampleNo. 1 2 3 4 5 6 7 8 9______________________________________ComponentPVP 45 40 50 50 40 45 50 50 40Epoxy 55 60 50 50 45 40 35 35 45Mela- 0 0 0 0 15 15 15 15 15mineP I 4 8 8 6 6 8 4 8 4Sol- S Co S Co Co Co Co S Svent______________________________________ Components were mixed together as specified and additional optional components (i.e. dyes, sensitizer, wetting agent and filler) were added. The solvent was added to the solids in a one-to-one weight ratio. Precleaned copper clad laminate panels (12"×12") were coated with each formulation using a draw down technique with a #65 Meier rod and dried for 30 to 40 minutes at 95° C. The boards were then exposed using the standard IPC-B25 primary image artwork. After exposure, panels were subjected to a first cure by heating for about 15 minutes at 95° C. Panels were then developed using an aqueous solution of 15 percent sodium hydroxide. After development, panels were subjected to a second cure by heating at 140° C. for 60 minutes. The boards coated with the above compositions were then tested for survival in an alkaline copper plating bath (pH>13) for periods of 7 hours on two consecutive days for a total of 14 hours exposure to the bath. The boards were evaluated based on three criteria: adhesion, halo or encroachment, and spots. The best indication of how well the board survived is by the number of squares which survived 14 hours in the alkaline copper plating bath without lifting from the copper substrate. Adhesion was measured by counting the squares below the pads on the IPC-B25 pattern. The best results are indicated by the highest number of squares remaining on the board after the test. Halo or encroachment was measured at specific locations, indicated by four areas of the IPC pattern, around the edges of a developed image. Halo's are indicative of non-adhesion in those areas and result in unsatisfactory electrical performance of the board. Each of the areas was measured for diameter of the halo and averaged. Because of the spacing between these four areas, a 15 mm encroachment was the worst score. The boards were also visually examined for spots in the unimaged area of the panel. A 1"×1" template was placed on the film in 5 random locations, and the number of spots were averaged. Spots indicate lack of chemical resistance of the coating. Results are shown in the following table where adhesion is in pounds per linear inch: TABLE 1______________________________________Example No. Adhesion Halo Spots______________________________________1 7 15.0 0.82 0 15.0 0.33 2 11.0 0.34 2 13.8 1.85 21 1.5 2.06 21 3.3 1.07 21 1.8 4.58 21 1.9 3.89 21 4.3 3.0______________________________________ Results show that the presence of melamine resin in Examples 5 to 9 significantly contributes to the number of squares that survive the 14 hour alkaline copper plating bath, and significantly reduces the size of the halo around developed areas. However, poly(vinylphenol) resins used in combination with melamine resins do not reduce the frequency of spots. Novolak resins appear to be more effective in reducing spot incidence. EXAMPLES 10 TO 18 In the following examples, the same materials were used except that a novolak resin formed by the condensation of formaldehyde with mixed cresols was substituted for the PVP. ______________________________________Ex-ampleNo. 10 11 12 13 14 15 16 17 18______________________________________ComponentNovo- 50 40 40 45 50 50 45 40 40lakEpoxy 50 60 60 55 35 35 40 45 45Mela- 0 0 0 0 15 15 15 15 15mineP I 4 8 4 8 4 8 6 8 8Sol- Co S S Co S Co Co Co Svent______________________________________ Preparation, processing and evaluation were all in accordance with the procedures of Example 1. The results are shown in the following table. TABLE 2______________________________________Example No. Adhesion Halo Spots______________________________________10 21 15.0 0.811 2 15.0 0.312 1 15.0 0.513 10 15.0 0.014 21 2.0 0.015 21 1.5 0.016 21 1.0 0.017 21 1.5 0.018 21 1.1 0.0______________________________________ Results show that the presence of melamine resin in formulations 14 to 18 improves adhesion, significantly reduces the diameter of any halo and reduces the number of spots on the board. EXAMPLE 19 The following example comprises the most preferred embodiment of the invention. ______________________________________ Parts by Weight______________________________________Mixed Cresol Novolak Resin 45.0Bisphenol A/Epichlorohydrin Epoxy Resin 30.0Triarylsulfonium hexafluroantimonate 4.0Hexamethoxymethylmelamine 15.0Filler (talc) 35.0Additives such as dyes and photosensitizer 3.5Propylene glycol methyl ether acetate - 100.0Dipropylene glycol methyl ether acetatemixed solvent______________________________________ While particular embodiments of the invention have been described in the above Examples, it will be understood that the invention is not limited thereto since various modifications may be made.
A photoimageable composition and process for use of the same. The composition comprises a binder that is a mixture of a phenolic resin and a multifunctional epoxy or vinyl ether pound and a curing system comprising a photoactive compound capable of generating a curing catalyst capable of crosslinking the binder components. The process for use of the composition comprises application of the composition to a substrate, drying of the same, exposing the dried coating to activating radiation, curing the binder in light exposed areas, developing the coating and thermally curing the developed image. The composition is especially useful as a solder mask.
8
RELATED APPLICATION This application is a continuation-in-part application of U.S. Ser. No. 09/670,208 filed Sep. 25, 2000 allowed. FIELD OF INVENTION The present invention relates generally to an automatic dishwasher detergent composition in the form of an aqueous liquid, wherein the composition is pink in color. BACKGROUND OF THE INVENTION Liquid automatic dishwasher detergent compositions, both aqueous and nonaqueous, have recently received much attention, and the aqueous products have achieved commercial popularity. The acceptance and popularity of the liquid formulations as compared to the more conventional powder products stems from the convenience and performance of the liquid products. However, even the best of the currently available liquid formulations still suffer from two major problems, product phase instability and bottle residue, and to some extent cup leakage from the dispenser cup of the automatic dishwashing machine as well as unacceptable color appearance. Representative of the relevant patent art in this area, mention is made of Rek, U.S. Pat. No. 4,556,504; Bush, et al., U.S. Pat. No. 4,226,736; Ulrich, U.S. Pat. 4,431,559; Sabatelli, U.S. Pat. No. 4,147,650; Paucot, U.S. Pat. No. 4,079,015; Leikhem, U.S. Pat. No. 4,116,849; Milora, U.S. Pat. No. 4,521,332; Jones, U.S. Pat. No. 4,597,889; Heile, U.S. Pat. No. 4,512,908; Laitem, U.S. Pat. No. 4,753,748; Sabatelli, U.S. Pat. No. 3,579,455; Hynam, U.S. Pat. No. 3,684,722: other patents relating to thickened detergent compositions include U.S. Pat. No. 3,985,668; U.K. Pat. No. Applications GB 2,116,199A and GB 240,450A; U.S. Pat. No. 4,511,487; U.S. Pat. No. 4,752,409 (Drapier, et al.); U.S. Pat. No. 4,801,395 (Drapier, et al.); U.S. Pat. No. 4,801,395 (Drapier, et al.). All of the prior art examples are yellow in yellow. The instant compositions are bleach stable and pink in appearance. SUMMARY OF THE INVENTION According to the present invention there is provided a novel aqueous liquid automatic dishwasher detergent composition which is pink in color and bleach stable. The composition is characterized by its substantially indefinite stability against phase separation or settling of dissolved or suspended particles, low levels of bottle residue, relatively high bulk density, a pink colored composition which is stable in the presence of bleach and substantial absence of unbound or free water. This unique combination of properties is achieved by virtue of the incorporation into the aqueous mixture of dishwashing detergent surfactant, optionally, an alkali metal detergent builder salt(s), chlorine bleach compound, an effective amount of high molecular weight cross-linked polyacrylic acid type thickening agent; a physical stabilizing amount of a long chain fatty acid or salt thereof; optionally, a noncrosslinked polyacrylate type polymer and a bleach stable red colorant thereby forming a pink colored liquid gelled automatic dishwashing composition. The compositions are further characterized by a bulk density of at least 1.24 g/cc, such that the density of the polymeric phase and the density of the aqueous (continuous) phase are approximately the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The compositions of this invention are pink colored, aqueous liquids containing various cleansing active ingredients, detergent adjuvants, structuring and thickening agents and stabilizing components, although some ingredients may serve more than one of these functions. The advantageous characteristics of the compositions of this invention, including a bleach stable pink color physical stability, low bottle residue, high cleaning performance, e.g. low spotting and filming, food removal, and so on, and superior aesthetics, are believed to be attributed to several interrelated factors such as low solids, i.e. undissolved particulate content, product density and linear viscoelastic rheology. These factors are, in turn, dependent on several critical compositional components of the formulations, namely, (1) the inclusion of a thickening effective amount of polymeric thickening agent having high water absorption capacity, exemplified by high molecular weight cross-linked polyacrylic acid, (2) inclusion of a physical stabilizing amount of a long chain fatty acid or salt thereof, (3) a product bulk density of at least 1.24 g/cc, such that the bulk density and liquid phase density are about the same. The pink colored, liquid gelled automatic dishwashing composition comprises approximately by weight: (a) 0.1% to 55%, more preferably 5% to 40% of an inorganic compound containing alkali metal cations, preferably sodium ions, wherein said inorganic compound is selected from the group consisting of alkali metal detergent builder salts, alkali metal hydroxides and alkali metal silicates and mixtures thereof; (b) 0.1% to 5% of at least one chlorine bleach stable, water-dispersible organic detergent active material; (c) 0 to 2%, more preferably 0.05% to 1.75% chlorine bleach stable foam depressant; (d) at least one chlorine bleach compound in an amount to provide about 0.2% to 4% of available chlorine; (e) 0.1% to 2.5%, more preferably 0.2% to 1.5% of a high molecular weight hydrophilic cross-linked polyacrylic acid thickening agent; (f) 0 to 5%, more preferably 0. 1% to 4.0% of a low molecular weight non-crosslinked polyacrylate-type polymer; (g) 0 to 2%, more preferably 0.05% to 1% of a long chain fatty acid or a metal salt of a fatty acid; (h) 0.001% to 0.5%, more preferably 0.001% to 0.2% of a F203 C.l. Pigment Red 1010 colorant; and (i) the balance being water, wherein the composition is pink in color and has chromaticity coordinate values of x from about 0.3142 to about 0.3300 and, more preferably about 0.3162 to about 0.3290 and y from about 0.3233 to about 0.3450, more preferably 0.3253 to 0.3425. The x and y values were obtained from the tristimulus values (x, y and z) obtained from measurements made using a QA Master spherical spectrophotometer (X-Rite Corp.), 10 degree observer, D65 illuminant at 25° C. and calibrated BTILL=barium sulfate, reflectance mode, specular component included, UV component included, large area view (sample and lens). CIELAB coordinates in the CIELAB system for the composition are (a) equals from about 1.25 to about 1.75, more preferably about 1.30 to about 1.64 and (b) from about −0.1 to about +4.0, more preferably from about −0.05 to about +3.5; L is about 28 to about 40, more preferably about 30 to about 39, C is about 1.0 to about 4, more preferably about 1.25 to about 3.75 and h is about −0.1 to about +0.1, more preferably about −0.05 to about +0.05. Exemplary of the cross-linked polyacrylic acid-type thickening agents are the products sold by B.F. Goodrich under their Carbopol trademark, especially Carbopol 941, which is the most ion-insensitive of this class of polymers, and Carbopol 940 and Carbopol 934. The Carbopol resins, also known as “Carbomer”, are hydrophilic high molecular weight, cross-linked acrylic acid polymers having an average equivalent weight of 76, and the general structure illustrated by the following formula: Carbopol 941 has a molecular weight of 1,250,000; Carbopol 940 a molecular weight of approximately 4,000,000 and Carbopol 934 a molecular weight of approximately 3,000,000. The Carbopol resins are cross-linked with polyalkenyl polyether, e.g. 1% of a polyallyl ether of sucrose having an average of 5.8 allyl groups for each molecule of sucrose. Further detailed information on the Carbopol resins is available from B.F. Goodrich, see, for example, the B.F. Goodrich catalog GC-67, Carbopol® Water Soluble Resins. While most favorable results have been achieved with Carbopol 614 or 617 from BF Goodrich or the Polygel series from 3V Company, preferably Polygel TL, other lightly cross-linked polyacrylic acid-type thickening agents can also be used in the compositions of this invention. As used herein “polyacrylic acid-type” refers to water-soluble homopolymers of acrylic acid or methacrylic acid or water-dispersible or water-soluble salts, esters or amides thereof, or water-soluble copolymers of these acids of their salts, esters or ameides with each other or with one or more other etylenically unsaturated monomers, such as, for example, styrene, maleic acid, maleic anhydride, 2-hydroxyethylacrylate, acrylonitrile, vinyl acetate, ethylene, propylene, and the like. These homopolymers or copolymers are characterized by their high molecular weight, in the range of from about 500,000 to 10,000,000, preferably 500,000 to 5,000,000, especially from 1,000,000 to 4,000,000, and by their water solubility, generally at least to an extent of up to 5% by weight, or more, in water at 250° C. These thickening agents are used in their lightly cross-linked form wherein the cross-linking may be accomplished by means known in the polymer arts, as by irradiation, or, preferably, by the incorporation into the monomer mixture to be polymerized of known chemical cross-linking monomeric agents, typically polyunsaturated (e.g. diethylenically unsaturated) monomers, such as, for example, divinylbenzene, divinylether of diethylene glycol, N, N′-methylene-bisacrylamide, polyalkenylpolyethers (such as described above), and the like. Typically, amounts of cross-linking agent to be incorporated in the final polymer may range from about 0.01 to about 1.5 percent, preferably from about 0.05 to about 1.2 percent, and especially, preferably from about 0.1 to about 0.9 percent, by weight of cross-linking agent to weight of total polymer. Generally, those skilled in the art will recognize that the degree of cross-linking should be sufficient to impart some coiling of the otherwise generally linear polymeric compound while maintaining the cross-linked polymer at least water dispersible and highly water-swellable in an ionic aqueous medium. It is also understood that the water-swelling of the polymer which provides the desired thickening and viscous properties generally depends on one or two mechanisms, namely, conversion of the acid group containing polymers to the corresponding salts, e.g. sodium, generating negative charges along the polymer backbone, thereby causing the coiled molecules to expand and thicken the aqueous solution; or by formation of hydrogen bonds, for example, between the carboxyl groups of the polymer and hydroxyl donor. The former mechanism is especially important in the present invention, and therefore, the preferred polyacrylic acid-type thickening agents will contain free carboxylic acid (COOH) groups along the polymer backbone. Also, it will be understood that the degree of cross-linking should not be so high as to render the cross-linked polymer completely insoluble or non-dispersible in water or inhibit or prevent the uncoiling of the polymer molecules in the presence of the ionic aqueous system. The amount of the high molecular weight, cross-linked polyacrylic acid or other high molecular weight, hydrophilic cross-linked polyacrylic acid-type thickening agent to impart the desired Theological property of linear viscoelasticity will generally be in the range of from about 0.1 to 2.5%, preferably from about 0.2 to 1.5%, by weight, based on the weight of the composition, although the amount will depend on the particular cross-linking agent, ionic strength of the composition, hydroxyl donors and the like. Specific examples of the alkali metal detergent builder salts include the polyphosphates, such as alkali metal pyrophosphate, alkali metal tripolyphosphate, alkali metal metaphosphate, and the like, for example, sodium or potassium tripolyphosphate (hydrated or anhydrous), tetrasodium or tetrapotassium pyrophosphate, sodium or potassium hexa-metaphosphate, trisodium or tripotassium orthophosphate and the like, sodium or potassium carbonate, sodium or potassium citrate, sodium or potassium nitrilotriacetate, and the like. The phosphate builders, where not precluded due to local regulations, are preferred and mixtures of tetrapotassium pyrophosphate (TKPP), potassium tripolyphosphate (KTPP), and sodium tripolyphosphate (NaTPP) (especially the hexahydrate) are especially preferred. Typical ratios of NaTPP to TKPP are from about 2:1 to 1:8, especially from about 1:1.1 to 1:6. The total amount of detergent builder salts is preferably from about 2 to 15%. The gelled compositions of this invention may, contain a small, but stabilizing effective amount of a long chain fatty acid or monovalent or polyvalent salt thereof. Although the manner by which the fatty acid or salt contributes to the rheology and stability of the composition has not been fully elucidated it is hypothesized that it may function as a hydrogen bonding agent or cross-linking agent for the polymeric thickener. The preferred long chain fatty acids are the higher aliphatic fatty acids having from about 8 to 22 carbon atoms, more preferably from about to carbon atoms, and especially preferably from about 12 to 18 carbon atoms, and especially preferably from 12 to 18 carbon atoms, inclusive of the carbon atom of the carboxyl group of the fatty acid. The aliphatic radical may be saturated or unsaturated and may be straight or branched. Straight chain saturated fatty acids are preferred. Mixtures of fatty acids may be used, such as those derived from natural sources, such as tallow fatty acid, coco fatty acid, soya fatty acid, mixtures of these acids, etc. Stearic acid and mixed fatty acids, e.g. stearic acid/palmitic acid, are preferred. Thus, examples of the fatty acids include, for example, decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, behenic acid, oleic acid, eicosanoic acid, tallow fatty acid, coco fatty acid, soya fatty acid, mixtures of these acids, etc. Stearic acid and mixed fatty acids, e.g. stearic acid/palmitic acid, are preferred. When the free acid form of the fatty acid is used directly it will generally associate with the potassium and sodium ions in the aqueous phase to form the corresponding alkali metal fatty acid soap. However, the fatty acid salts may be directly added to the composition as sodium salt or potassium salt, or as a polyvalent metal salt, although the alkali metal salts of the fatty acids are preferred fatty acid salts. The preferred polyvalent metals are the di- and tri-valent metals of Groups IIA, IIB and IIIB, such as magnesium, calcium, aluminum and zinc, although other polyvalent metals, including those of Groups IIIA, IVA, VA, IB, IVB, VB VIB, VIIB and VIII of the Periodic Table of the Elements can also be used. Specific examples of such other polyvalent metals include Ti, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc. Generally, the metals may be present in the divalent to pentavalent state. Preferably the metal salts are used in their higher oxidation states. Naturally, for use in automatic dishwashers, as well as any other applications where the invention composition will or may come in contact with articles used for the handling, storage or serving of food products or which otherwise may come into contact with or be consumed by people or animals, the metal salt should be selected by taking into consideration the toxicity of the metal. For this purpose, the alkali metal and calcium and magnesium salts are especially higher preferred as generally safe food additives. The amount of the fatty acid or fatty acid salt stabilizer to achieve the desired enhancement of physical stability will depend on such factors as the nature of the fatty acid or its salt, the nature and amount of the thickening agent, amount of the acidic sol of the alumina, detergent active compound, inorganic salts, other ingredients, as well as the anticipated storage and shipping conditions. Generally, however, amounts of the fatty acid or fatty acid salt stabilizing agents in the range of from about 0 to 2%, preferably 0.05 to 1%, more preferably from about 0.08 to 0.8% provide a long term stability and absence of phase separation upon standing or during transport at both low and elevated temperatures as are required for a commercially acceptable product. Depending on the amounts, proportions and types of fatty acid physical stabilizers, the amount of the acidic sol of the alumina and polyacrylic acid-type thickening agents, the addition of the fatty acid or salt not only increases physical stability but also provides a simultaneous increase in apparent viscosity. Foam inhibition is important to increase dishwasher machine efficiency and minimize destabilizing effects which might occur due to the presence of excess foam within the washer during use. Foam may be reduce by suitable selection of the type and/or amount of detergent active material, the main foam-producing component. The degree of foam is also somewhat dependent on the hardness of the wash water in the machine whereby suitable adjustment of the proportions of the builder salts such as NaTPP which has a water softening effect, may aid in providing a degree of foam inhibition. However, it is generally preferred to include a chlorine bleach stable foam depressant or inhibitor. Particularly effective are the alkyl phosphoric acid esters of the formula and especially the alkyl acid phosphate esters of the formula In the above formulas, one or both R groups in each type of ester may represent independently a C 12 -C 20 alkyl or ethoxylated alkyl group. The ethoxylated derivatives of each type of ester, for example, the condensation products of one mole of ester with from 1 to moles, preferably 2 to 6 moles, more preferably 3 or 4 moles, ethylene oxide can also be used. Some examples of the foregoing are commercially available, such as the products SAP from Hooker and LPKN158 from Clariant. Mixtures of the two types, or any other chlorine bleach stable types, or mixtures of mono- and di-esters of the same type, may be employed. Especially preferred is a mixture of mono- and di-C 16 -C 18 alkyl acid phosphate esters such as monostearyl/distearyl acid phosphates 1.2/1, and the 3 to 4 mole ethylene oxide condensates thereof. When employed, proportions of 0.05 to 2.0 weight percent, preferably 0.1 to 0.5 weight percent, of foam depressant in the composition is typical, the weight ratio of detergent active component (d) to foam depressant (e) generally ranging from 10:1 to 1:1 and preferably 5:1 to 1:1. Other defoamers which may be used include, for example, the known silicones, such as available from Dow Chemicals. In addition, it is an advantageous feature of this invention that many of the stabilizing salts, such as the stearate salts, for example, aluminum stearate, when included, are also effective as foam killers. Although any chlorine bleach compound may be employed in the compositions of this invention, such as dichloro-isocyanurate, dichloro-dimethyl hydantoin, or chlorinated TSP, alkali metal or alkaline earth metal, e.g. potassium, lithium, magnesium and especially sodium, hypochlorite is preferred. The composition should contain sufficient amount of chlorine bleach compound to provide about 0.2 to 4.0% by weight of available chlorine, as determined, for example by acidification of 100 parts of the composition with excess hydrochloric acid. A solution containing about 0.2 to 4.0% by weight of sodium hypochlorite contains or provides roughly the same percentage of available chlorine. About 0.8 to 1.6% by weight of available chlorine is especially preferred. For example, sodium hypochlorite (NaOCI) solution of from about 11 to about 13% available chlorine in amounts of about 3 to 20%, preferably about 7 to 12%, can be advantageously used. Detergent active material useful herein should be stable in the presence of chlorine bleach, especially hypochlorite bleach, and for this purpose those of the organic anionic, amine oxide, phosphine oxide, sulphoxide or betaine water dispersible surfactant types are preferred, the first mentioned anionics being most preferred. Particularly preferred surfactants herein are the linear or branched alkali metal mono- and/or di-(C 8 -C 14 ) alkyl diphenyl oxide mono- and/or di-sulphates, commercially available for example as DOWFAX (registered trademark) 3B-2 and DOWFAX 2A-1. In addition, the surfactant should be compatible with the other ingredients of the composition. Other suitable organic anionic, non-soap surfactants include the primary alkylsulphates, alkylsulphonates, alkylarylsulphonates and sec.-alkylsulphates. Examples include sodium C 10 -C 18 alkylsulphates such as sodium dodecylsulphate and sodium tallow alcoholsulphate; sodium C 10 -C 18 alkanesulphonates such as sodium hexadecyl-1-sulphonate and sodium C 12 -C 18 alkylbenzenesulphonates such as sodium dodecylbenzenesylphonates. The corresponding potassium salts may also be employed. As other suitable surfactants or detergents, the amine oxide surfactants are typically of the structure R 2 R 1 NO, in which each R represents a lower alkyl group, for instance, methyl, and R 1 represents a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or cetyl group. Instead of an amine oxide, a corresponding surfactant phosphine oxide R 2 R 1 PO or sulphoxide RR 1 SO can be employed. Betaine surfactants are typically of the structure R 2 R 1 N+RCOO-, in which each R represents a lower alkylene group having from 1 to 5 carbon atoms. Specific examples of these surfactants include lauryl-dimethylamine oxide, myristyl-dimethylamine oxide, myristyl-dimethylamine oxide, the corresponding phosphine oxides and sulphoxides, and the corresponding betaines, including dodecyidimethylammonium acetate, tetradecyidiethylammonium pentanoate, hexadecyldimethylammonium hexanoate and the like. For biodegradability, the alkyl groups in these surfactants should be linear, and such compounds are preferred. Surfactants of the foregoing type, all well known in the art, are described, for example, in U.S. Pat. Nos. 3,985,668 and 4,271,030. If chlorine bleach is not used than any of the well known low-foaming nonionic surfactants such as alkoxylated fatty alcohols, e.g. mixed ethylene oxide-propylene oxide condensates of C 8 -C 22 fatty alcohols can also be used. The chlorine bleach stable, water dispersible organic detergent-active material (surfactant) will normally be present in the composition in minor amounts, generally about 1% by weight of the composition, although smaller or larger amounts, such as up to about 5%, such as from 0.1 to 5%, preferably form 0.3 or 0.4 to 2% by weight of the composition, may be used. Alkali metal (e.g. potassium or sodium) silicate, which provides alkalinity and protection of hard surfaces, such as fine china glaze and pattern, is generally employed in an amount ranging from about to weight percent, preferably about 5 to 15 weight percent, more preferably 8 to 12% in the composition. The sodium or potassium silicate is generally added in the form of an aqueous solution, preferably having Na 2 O:SiO 2 or K 2 O:SiO 2 ratio of about 1:1.3 to 1:2.8, especially preferably 1:2.0 to 1:2.6. At this point, it should be mentioned that many of the other components of this composition, especially alkali metal hydroxide and bleach, are also often added in the form of a preliminary prepared aqueous dispersion or solution. In addition to the detergent active surfactant, foam inhibitor, alkali metal silicate corrosion inhibitor, and detergent builder salts, which all contribute to the cleaning performance, it is also known that the effectiveness of the liquid automatic dishwasher detergent compositions is related to the alkalinity, and particularly to moderate to high alkalinity levels. Accordingly, the compositions of this invention will have pH values of at least about 9.5, preferably at least about 11 to as high as 14, generally up to about 13 or more, and, when added to the aqueous wash bath at a typical concentration level of grams per liter, will provide a pH in the wash bath of at least 9, preferably at least about 10, such as 10.5, 11, 11.5 or 12 or more. The alkalinity will be achieved, in part by the alkali metal ions contributed by the alkali metal detergent builder salts, e.g. sodium tripolyphosphate, tetrapotassium pyrophosphate, and alkali metal silicate, however, it is usually necessary to include at least alkali metal hydroxide, e.g. NaOH or KOH, to achieve the desired high alkalinity. Other alkali metal salts, such as alkali metal carbonate may also be present in the compositions in minor amounts, for example from 0 to 4%, preferably 0.1 to 2%, by weight of the composition. The preferred low molecular noncrosslinked polyacrylate polymer is an alkali metal salt such as sodium of a noncrosslinked polyacrylic acid homopolymer having a molecular weight of about 1,000 to about 20,000, preferably about 2,000 to about 4,000. A preferred polymer is Aucsol™ 445N sold by Rohm Haas which has a molecular weight of about 4,500. The red colorant that is bleach stable which is used in the instant compositions is a ferric oxide (Fe203) red pigment sold by Bayer as Levanox Red 130LF01 red dispersion pigment of 60-65% Cl pigment. Red 101, silicon dioxide<3%, nonionic surfactant dispersant 5-10% and the balance being water. A solution of 98.7% of water, 0.8% Levanox Red 130 LFO1 dispersion and 0.5 of 50% sodium hydroxide aqueous solution is prepared and added to the liquid, gel automatic dishwashing composition. Other conventional ingredients may be included in these compositions in small amounts, generally less than 3 weight percent, such as perfume, hydrotropic agents such as the sodium benzene, toluene, xylene and cumene sulphonates and preservatives, all of course being stable to chlorine bleach compound and high alkalinity. The manner of formulating the invention compositions is also important. As discussed above, the order of mixing the ingredients as well as the manner in which the mixing is performed will generally have a significant effect on the properties of the composition, and in particular on product density (by incorporation and stabilization of more or less air) and physical stability (e.g. phase separation). Thus, according to the preferred practice of this invention the compositions are prepared by first forming a dispersion of the polyacrylic acid-type thickener and the low molecular weight noncrosslinked polyacrylate in water under moderate to high shear conditions, neutralizing the dissolved polymer to cause gelation and then introducing, while continuing mixing, the detergent builder salts, alkali metal dilicates, chlorine bleach compound and remaining detergent additives, including any previously unused alkali metal hydroxide, if any, other than the surface-active compounds. All of the additional ingredients can be added simultaneously or sequentially. Preferably, the ingredients are added sequentially, although it is not necessary to complete the addition of one ingredient before beginning to add the next ingredient. Furthermore, one or more of these ingredients can be divided into portions and added at different times. These mixing steps should also be performed under moderate to high shear rates to achieve complete and uniform mixing. These mixing steps may be carried out at room temperature, although the polymer thickener neutralization (gelation) is usually exothermic. The composition may be allowed to age, if necessary, to cause dissolved or dispersed air to dissipate out of the composition. The remaining surface active ingredients, including the anti-foaming agent, organic detergent compound, and fatty acid or fatty acid salt stabilizer is post-added to the previously formed mixture in the form of an aqueous emulsion (using from about 1 to 10%, preferably from about 2 to 4% of the total water added to the composition other than water added as carrier for other ingredients or water of hydration) which is pre-heated to a temperature in the range of from Tm+5 to Tm−20, preferably from Tm to TM−10, where Tm is the melting point temperature of the fatty acid or fatty acid salt. For the preferred stearic acid stabilizer the heating temperature is in the range of 50° C. to 70° C. However, if care is taken to avoid excessive air bubble incorporation during the gelatin step or during the mixing of the detergent builder salts F203 (ferric oxide) red pigment and other additives, for example, by operating under vacuum, or using low shearing conditions, or special mixing operatatus, etc., the order of addition of the surface active ingredients should be less important. The compositions will be supplied to the consumer in suitable dispenser containers preferably formed of molded plastic, especially polyolefin plastic, and most preferably polyethylene, for which the invention compositions appear to have particularly favorable slip characteristics. In addition to their linear viscoelastic character, the compositions of this invention may also be characterized as pseudoplastic gels (non-thixotropic) which are typically near the borderline between liquid and solid viscoelastic gel, depending, for example, on the amount of the polymeric thickener. The invention compositions can be readily poured from their containers without any shaking or squeezing, although squeezable containers are often convenient and accepted by the consumer for gel-like products. The liquid, gelled automatic dishwasher compositions of this invention are readily employed in known manner for washing dishes, other kitchen utensils and the like in an automatic dishwasher, provided with a suitable detergent dispenser, in an aqueous wash bath containing an effective amount of the composition, generally sufficient to fill or partially fill the automatic dispenser cup of the particular machine being used. The invention also provides a method for cleaning dishware in an automatic dishwashing machine with an aqueous wash bath containing an effective amount of the liquid, gelled automatic dishwasher detergent composition as described above. The composition can be readily poured from the polyethylene container with little or no squeezing or shaking into the dispensing cup of the automatic dishwashing machine and will be sufficiently viscous and cohesive to remain securely within the dispensing cup until shear forces are again applied thereto, such as by the water spray from the dishwashing machine. The invention may be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying examples. All the amounts and proportions referred to herein are by weight of the composition unless otherwise indicated. EXAMPLE 1 The following formulations A-F were prepared as described below: INGREDIENT/FORMULATION A B C D E F Sodium tripolyphosphate 6 6 6 6 6 Sodium disilicate 12 12 12 12 12 Potassium hydroxide 3.89 3.89 3.89 3.89 3.89 Sodium hydroxide 0.87 0.87 0.87 0.87 0.87 0.87 Acusol 445N 1.92 1.92 1.92 1.92 1.92 Carbopol 617 0.7 0.7 0.7 0.7 0.7 0.7 Dowfax 3B2 0.23 0.23 0.23 0.23 0.23 0.23 LPKn 158 0.16 0.16 0.16 0.16 0.16 Stearic acid 0.11 0.11 0.11 0.11 0.11 Sodium hypochlorite (13% solution) 9.2 9.2 9.2 9.2 9.2 9.2 Perfume 0.1 0.1 0.1 0.1 0.1 Water Bal. Bal. Bal. Bal. Bal. Bal. Levanox Red Fe2O3 pigment (Cl 0.002 0.002 pigment Red No. 1) FD & C Red #3 0.002 Graphol Red 1116-2 0.002 Xylene Red B 0.002 Vibracolor Red PRE5-L 0.002 Color stability for 13 weeks at 77° F. 100° F. CIE coordinates x 0.3192 0.3289 y 0.3283 0.3412 CIE tresilicas values X 11.21 10.32 Y 11.53 10.70 Z 12.38 10.35 CIELAB coordinates a 1.49 b 0.00 L 33.96 h 0.00 c 1.49
A pink colored automatic dishwasher detergent composition is formulated as a gel-like aqueous product of exceptionally good physical stability, low bottle residue, low cup leakage, red color stability and improved cleaning performance.
2
The present invention relates to microbiological chiral reduction of carbonyl groups and to a novel microorganism for carrying out this reduction. More particularly, the invention relates to the microbiological chiral reduction of ketone groups. The novel microorganism is Aspergillus niveus (ATCC 20922). The invention also relates to a process for preparing the compound dilevalol using the novel microorganism. The compound (-)-5- {(1R)-1-hydroxy-2-[(1R)-1-methyl-3-phenylpropyl)amino]ethyl} salicylamide monohydrochloride, Compound I, also known as dilevalol hydrochloride, exhibits potent vasodilating β-adrenergic blocking activity and is useful for the treatment of hypertension; see U.S. Pat. No. 4,619,919. ##STR1## Stereospecific processes for preparing dilevalol are described in the above noted patent and in U.S. Pat. No. 4,658,060. In preparing dilevalol, chiral reduction of a ketone group is required to afford the proper R stereoisomer configuration. The inventor investigated more than 50 cultures of microorganisms reported to reduce ketone groups to hydroxy groups, for example, bacterial such as Schizomycetes; fungi, such as Ascomycetes, Basidiomycetes and Phycomycetes; however none of the microorganisms tested were active in reducing the ketone group to the proper R stereoisomer. The inventor then searched for new microorganisms from the soil and discovered a microorganism, Aspergillus niveus which was capable of reducing the ketone group to a hydroxy group having the proper R stereo configuration. SUMMARY OF THE INVENTION The present invention embraces the novel microorganism Aspergillus niveus (ATCC 20922) and mutants and variants thereof having the distinguishing characteristics of Aspergillus niveus. The present invention is also directed to a process for chiral reduction of ketone groups to hydroxy groups, which comprises cultivating the microorganism Aspergillus niveus in a medium to which a ketone compound has been added so that a stereospecific hydroxy group can be formed and accumulated in said medium, and collecting said hydroxy compound. The process is particularly useful in preparing dilevalol from 5-{(R)-[(1-methyl-3-phenylpropyl)amino]acetyl} salicylamide. DETAILED DESCRIPTION OF THE INVENTION The microorganim Aspergillus niveus was discovered and isolated by the present inventor from soil obtained from an excavation site in Union, N.J., U.S.A. Separation of the microorganism was accomplished by the soil enrichment method, wherein a sample of soil is mixed with a compound which restricts the growth to those organisms that can use that compound. In this particular case, the compound 5-(methoxyacetyl)-2-hydroxybenzamide was added to the soil sample and the mixture was incubated for several days. From time to time the mixture was sampled using standard microbiological methods and plated out. A number of isolates were purified and tested. One of the isolates was very active in reducing the ketone group of the test substrate. This active pure culture, a white mold, was characterized as belonging to the genus Aspergillus and was further identified as Aspergillus niveus. The bacteriological characteristics of Aspergillus niveus are as follows: (a) Growth in various media: (1) Malt extract agar medium: It grows in abundance in this medium forming a white colony, raised and floccose in center, smooth, with condial heads not apparent to the unaided eye. Outer portion of colony flat, velvety, consisting of abundant conidial heads arising from hyphae appressed to the surface of the agar. Exudate lacking. Colony reverse yellow-brown. Conidial heads at first radiate, becoming loose columnar, sometimes flaring slightly at apex, white, Conidiophores erect, with a distinct foot cell, relatively thick-walled, sometimes with septa, occasionally branched. Conidiophores hyaline in optical view but with a distinct brownish tint in surface view. Apex of conidiophore enlarging gradually to form a vesicle. Vesicles hemisphaerical, bearing sporogenous apparatus on upper surface. Sporogenous apparatus biseriate, but occasionally uniseriate, especially in small heads or at margin of vesicle. Biseriate heads consisting of metulae, bearing phialides that taper to a slender tip. Phialides bearing long chains of conidia. Conidia globose, smooth, thin-walled, hyaline. (2) Czapek agar medium: It grows in abundance in this medium forming a colony heavily floccose, surface appearing smooth and compact with conidial heads not apparent to the unaided eye. Colony white, with a light yellowish-cream or buff color with age. Conidial heads formed amidst aerial mycelium of colony as described on malt extract agar, except slightly smaller and not as uniformly columnar. (3) V-8 juice agar medium: It grows in abundance in this medium forming a white colony, heavily floccose in center, moderately floccose in outer region; center of colony soon becoming light yellow, entire colony cream to yellow-buff with age. Conidial heads abundant, formed on aerial mycelium, as described on malt extract agar. (b) Physiological Properties; (1) Formation of aflatoxin: negative. (c) Source: soil A viable culture of Aspergillus niveus has been deposited in the collection of the American Type Culture Collection (ATCC) in Rockville, Md., where it has been assigned accession number ATCC 20922. Should the deposited culture become lost, destroyed on non-viable during the longer of the thirty (30) year period from the date the culture was deposited or the five (5) year period after the last request for the deposited culture or the effective life of the patent which issues from this application, the culture will be replaced, upon notice, by applicants or assignee(s) of this application. Subcultures of Aspergillus niveus, ATCC 20922, are available during the pendency of this application to one determined by the Commissioner of Patents and Trademarks to be entitled thereto under 37 CFR 1.14 and 35 USC 122 and will be available to the public without restriction once a patent based on this application is granted. Use of the microorganism is dependent on the US Patent Laws. The process aspect of the present invention provides a method for microbiological chiral reduction of ketone groups to the corresponding hydroxy group having the proper stereo configuration. The microbiological chiral reduction process of the present invention is illustrated by the preparation of dilevalol from 5- {((R)-[(1-methyl-3-phenylpropyl) amino]acetyl} salicylamide: ##STR2## The microbiological chiral reduction is carried out by adding the ketone substrate, compound II, to the culture broth of the microorganism. The incubation may be conducted at temperatures in the range between 26° C. and 35° C., but preferably in the range between 33° C. and 34° C., while maintaining the pH value of the reaction mixture in the range between 6.5 and 7.2, but preferably between 6.8 and 7.2. The concentration of the ketone substrate in the reaction mixture may vary from 10 to 50 mg/100 ml, and preferably 25 mg/100 ml. The duration of the chiral reduction reaction may vary from 48 to 120 hours, preferably 72 hours. At the end of the reduction reaction, there may be extracted from the reaction mixture dilevalol by using organic solvents, such as, for example, ethyl acetate, methylene chloride, and the like. From the organic extract thus obtained and concentrated, there may then be separated dilevalol. Purification of the hydroxy compound may be carried out by TLC and HPLC chromatography. Other known microorganisms of the genus Aspergillus have been investigated to determine whether other members of genus class would afford clincal reduction of keto groups. The following microorganisms failed to provide chiral reduction of ketone groups: Aspergillus niger (ATCC 1394); Aspergillus Orxyae (ATCC 1454); and Aspergillus Oryzae (ATCC 11488). The present invention will be described in more detail by the following examples. However, these examples are not intended to limit the scope of the present invention. EXAMPLE 1 The novel fungus Aspergillus niveus was isolated in pure culture by the "soil enhancement method". Master cultures of the active strain were prepared and maintained by the usual microbiological methods one or more of the following agar media: potato dextrose, Sabouraud's agar and yeast extract dextrose agar. Inoculum for fermentation was prepared by subculture to the following sterile liquid medium: ______________________________________Ingredient Amount______________________________________Soy flour 35 gPotato dextrin 50 gCerelose 5 gCalcium carbonate 5 gCobalt chloride 6H.sub.2 O 2 mgSoft water to one literPost sterile pH 7.0-7.2______________________________________ The broth was dispensed into 300-ml flasks containing 100 ml of broth per flask. The flasks were seeded either with spores or mycelium from agar slants and incubated in a water temperature controlled shaker operated at 320 strokes per minute at 32°-34° C. Excellent growth was achieved in 18-48 hours. At that time the bio-conversion production medium was inoculated at 2.5% level with seed from the above-noted medium. The production medium comprises per liter: 5.6 grams of autolyzed yeast; 10 grams cerelose and 2.5 grams mono-basic potassium phosphate. The broth (100 ml) was dispensed into 300 ml flasks and sterilized at 121° C. for 30 minutes; post sterile pH 5.0-5.2. After inoculation, the flasks were placed in an incubator shaker running at 320 strokes per minute at 34° C. At the end of 24 hours, 50 mg of the hydrochloride salt of 5-{(R)-[(1-methyl-3-phenylpropyl)amino]acetyl} salicylamide either dry or dissolved in 1-2 ml of dimethylformamide was added to each flask and incubation continued on the shaker for 24-72 hours. Samples were taken periodically to determine the rate of conversion of the 5-{(R)-[(1-methyl-3-phenylpropyl)amino]acetyl} salicylamide to dilevalol. Sample size was 10 ml placed into a 25×150 ml test tube. Ethylacetate (25 ml) was then added to each tube and shaken 50-60 times. The solvent layer was allowed to settle and then drawn off and evaporated on a steam bath to dryness. The residue was dissolved in 2 ml of methanol and subjected to TLC and HPLC chromatography. Thin layer chromatography indicated a bioconversion of 70-80% of the 5-{(R)-[(1-methyl-3-phenylpropyl)amino]acetyl} salicylamide to dilevalol.
There is disclosed a novel microorganism Aspergillus niveus, ATCC 20922, and a process for chiral reduction of ketones using said mircoorganisms.
8
CROSS REFERENCE TO RELATED APPLICATION(S) This application claims the benefit of U.S. provisional patent application Ser. No. 61/793,814 (filed Mar. 15, 2013) which is incorporated herein by reference in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to tent stakes for use in securing tent structures, and in particular, to tent stakes have illumination capabilities. 2. Description of Related Art Assembly of tents often includes using tent stakes (or pegs) to anchor the tent to the ground. Tent stakes are typically constructed as a spike-like structure, made of metal, wood, plastic, or composite material, and can be driven into the ground and attached to the sheet material of the tent, or to ropes (or cords) attached to the tent. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a tent stake of the present disclosure. FIG. 2 is a back side plan view of the tent stake of FIG. 1 . FIG. 3 is a side elevation view of the tent stake of FIG. 1 . FIG. 4 is a front side plan view of the tent stake of FIG. 1 . FIG. 5 is a cross-sectional view of the tent stake of FIG. 4 , as viewed from line A-A in the direction of the arrows A-A as indicated in FIG. 4 . FIG. 6 a is a right side view of the tent stake of FIG. 1 , showing the tent stake driven into a ground surface, and a fastening cord attached to the tent stake, such as, for example, a rope, having an end-loop that is looped around the tent stake and hooked or retained within a lower holding notch section of the tent stake. FIG. 6 b is the tent stake of FIG. 1 , showing the lighting component with housing having been slidably positioned on a top portion of the tent stake, so that the tent stake can be driving deeper into the ground than in FIG. 6 a. FIG. 7 is a left side view of the tent stake of FIG. 1 , showing a fastening cord, such as, for example, a rope, having an end-loop that is looped around the tent stake and disposed within an upper holding notch section of the tent stake. FIG. 8 is a right side view of another embodiment of the tent stake of FIG. 1 , having only a front facing notch section on the body portion, showing the tent stake driven into a ground surface, and a fastening cord attached to the tent stake, such as, for example, a rope, having an end-loop that is looped around the tent stake and hooked or retained on laterally extending edges of the housing of the lighting component. FIG. 9 is a front elevation view of another embodiment of the tent stake of FIG. 1 , having hooks or notch sections provided on, or formed integral with, the housing for the lighting component. DETAILED DESCRIPTION In the present description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the disclosure. However, upon reviewing this disclosure one skilled in the art will understand that the various embodiments disclosed herein may be practiced without many of these details. In other instances, some well-known structures and materials associated with tents and tent stakes, switches, LEDs, and various materials of construction have not been described in detail to avoid unnecessarily obscuring the descriptions of the embodiments of the disclosure. In the present disclosure, to the extent the terms “about” and “approximately” are used, they mean ±20% of the indicated range, value, or structure, unless otherwise indicated. In the present description, the terms “a” and “an” as used herein refer to “one or more” of the enumerated components. The use of the alternative (e.g., “or”) should be understood to mean either one, both, or any combination thereof of the alternatives. As used herein, the terms “include” and “comprise” are used synonymously, which terms and variants thereof are intended to be construed as non-limiting. The definitions in this paragraph are intended to apply throughout this disclosure unless otherwise expressly stated. Various embodiments in this disclosure are described in the context of use with tents. However, as will be understood by those skilled in the art after reviewing this disclosure, various other structures may be suitable for use with the disclosed tent stakes, such as, for example, tarps or other sheet material used to cover objects. As best seen in FIGS. 1-4 , in some embodiments, a tent stake 2 is provided, which includes a body portion 4 , and a lighting component 6 . The lighting component 6 can have a lens 8 and a housing 10 . The body portion 4 can be constructed of, for example, aluminum, but various other materials of construction may also be suitable. In some embodiments, the body portion 4 is formed in the shape of two longitudinally extending walls 5 that meet at an angle (e.g., without limitation, between 60 and 90 degrees) at inward joined lateral edge portions thereof. In manufacturing, the two walls can be formed by creating a centerline longitudinally extending single bend or crease (e.g., a bend that defines the inward lateral edge portions of the walls 5 ) within a workpiece material of construction (e.g., a metal), with various pre-formed (e.g., pre-cut) features. The body portion 4 can have an upper hook-like notch section 13 at one end portion, with a lower hook-like notch section 11 , formed just below the upper hook-like notch section 13 . In addition, a pointed tip can be provided at an opposite end portion (for use in driving the tent stake 2 into a ground surface). Also, the body portion 4 can include further cut-out sections to, for example, reduce the weight of the tent stake 2 , or provide decorative appeal, without compromising its structural integrity suitable for use. As best seen in FIGS. 1 & 3 , in some embodiments, the upper hook-like notch section 13 comprises two laterally aligned cut-outs, one on each longitudinal wall 5 , opening on lateral outward edge portions of the longitudinal walls 5 , with upper edges 13 ′ of the cut-outs angled slightly downward as they extend outward, for use in securing a cord or other fastening member (as described further below). As best seen in FIGS. 1 & 3 , in some embodiments, the lower hook-like notch section 11 comprises a single cut-out, formed with a center thereof disposed at the joined edge portions of the longitudinal walls 5 , without opening on lateral outward edge portions of the longitudinal walls 5 , with an upper edge 11 ′ of the cut-out angled slightly downward as it extends toward its centerline at the joined walls, for use in securing a cord or other fastening member (as described further below). Referring to FIGS. 1 and 5 , the lens 8 of lighting component 6 , can be transparent or semitransparent, and house one or more LED(s) 14 , which can be attached to a circuit board 16 to mechanically support and electrically connect the LEDs 14 to a switch structure. The LED(s) 14 can rest just beneath the lens 8 , on the circuit board 16 . Also, power to the LED(s) 14 can be supplied by a battery, such as, for example, a single AAA battery 20 , housed within a battery cover 18 , within the housing 10 of the lighting component 6 . In some embodiments, the lens 8 can be constructed of a thermoplastic polymer, such as, for example, polypropylene (PP) plastic. Also, the housing 10 and/or battery cover 18 , can be constructed of, for example, a thermoplastic rubber or elastomeric material. Referring to FIGS. 1 & 5 , in some embodiments, the battery cover 18 and lens 8 are attached to the housing 10 , by being snap fit together from above and below a ridge 28 of the housing 10 . That is, for example, the lens 8 can have a base perimeter indent 26 , extending along all or a part of its base perimeter, and the battery cover 18 can have a corresponding inwardly extending edge 24 , that can be inserted into the indent 26 . The base 8 ″ of the lens 8 (having the perimeter indent 26 ) can be inserted into a top (“top,” relative to FIG. 5 ), or forward facing, opening 10 ′ of the housing 10 , with downward (“downward,” relative to FIG. 5 ) facing wall portions 8 ′ of the lens 8 abutting against the top surface of the housing ridge 28 . The perimeter indent 26 can be pressed into position between the inwardly extending edge 24 portions of the battery cover 18 below the housing ridge 28 . That is, the battery cover 18 can have spring characteristics allowing its edge portions 24 to expand outward under pressure to allow a base 8 ″ of the lens 8 to be pressed between the edge portions 24 , then allowing the edge portions 24 to be biased inward into the perimeter indent 26 of the base 8 ″ of the lens 8 , to grip the base 8 ″. A top surface 24 ′ of the battery cover 18 , or top of the edge portions 24 , can abut against a downward (“downward,” relative to FIG. 5 ) facing wall of the housing ridge 28 , thus cooperatively working with the base 8 ″ of the lens 8 to retaining the lens 8 and battery cover 18 attached to the housing 10 . The lens 8 can serve as a manually depressible switch, depressible from a resting position That is, for example, the lens 8 can be manually pressed (by pushing on its face), such as in the direction of arrow “B,” in FIG. 5 , and can float on the housing 10 , the housing serving as a deformable spring, so that when the lens is depressed, a switch on the circuit board 16 can be contacted to activate or deactivate the LED(s) 14 , as will be appreciated by those skilled in art after reviewing the present disclosure. The housing 10 can return the lens 8 to an original (e.g., resting) position after being depressed so that the lens 8 can be depressed again to switch the LED 14 off. However, in some embodiments, the LED 14 can have more than one mode. For example, the LED 14 can be switched on and provide continuous light in a “flood” mode, after a single press of the lens 8 . When the lens 8 is depressed a second time, the LED 14 can be switched to a second mode, in which it flashes at a pre-set rate. When the lens 8 is depressed a third time, the LED 14 can be switched off. In some embodiments, the housing 10 can be flexible and snuggly wrapped about an exterior portion of the walls 5 of the tent stake 2 body, as can be seen in FIGS. 1 , 5 . The housing 10 can be shorter in length along the centerline or bend between the walls 5 of the body portion 4 , and longer near lateral edge portions of the walls 5 . The battery cover 18 can be disposed within the housing 10 , but with a longitudinal gap 19 extending between the battery cover 18 and an inside wall surface of the housing 10 , the longitudinal gap 19 opening on both end portions of the housing 10 . The longitudinal gap 19 can be sized to snuggly accommodate the walls 5 of the tent stake body 4 . The tent stake 2 body 4 can thus be inserted through the gap 19 , between the housing 10 and the battery cover 18 , to snuggly hold the lighting component 6 on the tent stake body 4 , but to allow the lighting component 6 to be slidably movable along the length of the tent stake body 4 , as shown by arrows “C” in FIGS. 6 a & 7 . That is, the lighting component 6 can be selectively manually positioned along the length of the tent stake body 4 . Referring to FIGS. 6 a , 6 b , and 7 , in some embodiments, during use, the tent stake 2 can be driven into a ground surface 23 , and a cord 22 , or other flexible fastening member, can extend from a tent (not shown in the figures) to the tent stake 2 , to be attached, or hooked, on the tent stake 2 to provide tension to the cord, by being looped about the tent stake body 4 , and hooked, or otherwise retained, within an opposite facing lower notch section 11 , or upper notch section 13 , as will be appreciated by those skilled in the art after reviewing this disclosure. For example, as shown in FIGS. 6 a and 6 b , in some embodiments, when the lower notch section 11 is faced opposite a tent, the lens 8 of the lighting component 6 can face the tent. The tent (not shown in the drawings), is located in the direction from which the fastening cord 22 extends toward the tent stake 2 . In this position, a user can depress the lens 8 , and activate the LED to provide lighting to the tent with the lens 8 directly facing the tent, such as, for example, in a continuous light mode, or flood mode. In another example, as shown in FIG. 7 , when the upper notch section 13 is facing opposite the tent, the lens 8 of the lighting component can also face away from the tent. In this position, a user can depress the lens 8 , and activate the LED while the lens is facing away from the tent, such as, for example, in an LED flashing mode (or flood mode, if desired by a user), which can be useful for locating the tent in the dark, as will be appreciated by those skilled in the art after reviewing this disclosure. Referring to FIGS. 6 a and 6 b , in some embodiments, a user may slide the lighting component 6 (or housing 10 ) in the directions corresponding to arrows “C.” As best seen in FIG. 6 b , a user may slide the lighting component 6 up toward a top portion of the tent stake 2 , to be snuggly retained on a top end portion of the tent stake 2 , so that the tent stake 2 may be driven deeply into the ground 23 without abutting against the lighting component 6 . For example, in regular use, or during storage or transportation, a user may not want to position the lighting component 6 near an end portion of the tent stake, but may do so when the tent stake needs to be driven into the ground deeply, such as, in loosely packed ground. Sliding the lighting component 6 back downward on the tent stake body 4 provides for compact storage and can avoid the lighting component 6 sliding off, unless a stop feature is provided on the tent stake to prevent the lighting component 6 from sliding off the top end portion of the tent stake body 4 . Referring to FIG. 8 , in some embodiments of the present disclosure, only one notch section is provided on a single face, such as notch section 13 , on the front side of the tent stake 2 . However, in such embodiments, a user can still retain a tent cord 22 under tension on an opposite side of the notch section 13 , on the back side of the tent stake 2 , such as by, for example, placing the cord 22 (cord loop) wrapped about the tent stake 2 below the housing 10 of the lighting component, and allowing the cord 22 to abut against laterally extending lower edges 10 ′ of the housing 10 (See, e.g., FIGS. 4 & 8 ). In some embodiments, even though the laterally extending edges 10 ′ may be narrow (e.g., less than ½ cm, or ¼ cm), since the housing 10 is made of non-slick thermoplastic rubber or elastomer, friction between the cord 22 in tension and the housing can be sufficient to retain the cord from slipping away from, or past, the laterally extending edges 10 ′. In other embodiments, the lateral edges 10 ′ are wider than ½ cm. Also, in some embodiments, no notch sections are provided on the tent stake body 4 , either forward facing or backward facing, and the laterally extending edges 10 ′ of the housing 10 may be used to retain a cord 22 with the tent stake facing in either direction. Although the housing can be manually slidable, when the cord abuts against the housing, and the cord is in tension, since it is not parallel to the body portion 4 , only some component of the tension in the cord may be directed upward along the body portion 4 so that most of, or a substantial portion of, the force the cord exerts is not directed toward pushing the housing 10 upward. Furthermore, referring to FIG. 8 , the cord tension may cause some compression of the housing against the body portion 4 , thus also prevent the housing 10 from sliding when used to abut against the cord. Referring to FIG. 9 , in some embodiments of the present disclosure, hooks or notch sections can be provided on, or formed integral with, the housing 10 , for use in retaining the cord 22 . For example, as shown in FIG. 9 , a hook structures 10 ″ can be provided on either side of the housing 10 . In other embodiments, a hook (not shown in the drawings) could be formed on the back side of the housing 10 , extending directly backward away from the center line of the body portion 4 , as will be appreciated by those skilled in the art after reviewing this disclosure. In some embodiments, no notches are provided on the body portion 4 , for use in combination with the hook structures 10 ″ on the housing 10 , and the tent stake 2 could be used to retain the cord using only the housing 10 for the lighting component, with the tent stake facing toward or away from, the tent. Although specific embodiments of the present disclosure have been described supra for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in the relevant art after reviewing the present disclosure. The various embodiments described can be combined to provide further embodiments. The described structures and methods can omit some elements or acts, can add other elements or acts, or can combine the elements or execute the acts in a different order than that illustrated, to achieve various advantages of the disclosure. These and other changes can be made to the disclosure in light of the above detailed description. In general, in the following claims, the terms used should not be construed to limit the disclosure to the specific embodiments disclosed in the specification.
A tent stake has a lighting component. A portion of the lighting component can be disposed between walls of the tent stake, and slidably attached thereto. The lighting component can have a lens attached to a flexible housing of the lighting component. A light source of the lighting component can be actuated by manually depressing the lens, with the lens floating on the housing. Also, in some embodiments, the lens can be pressed multiple times to select different lighting modes.
4
FIELD OF THE INVENTION The invention relates to a packaging material for relatively rigid objects and further to a method for packing electrodes by supplying such a packaging material in two layers, adhering to each other, to a packing unit. BACKGROUND OF THE INVENTION A package for sterile objects, which are used by a surgeon, is known from U.S. Pat. No. 4,437,567. It is stated therein that the package may be made of conventional materials such as a plastic coated metal, glass, plastic film or sheet, plastic coated metal foil or metallized paper or other packaging material impervious to liquid and inert to contents of the package. From British Pat. No. 1,263,217 a packaging material is known for packaging sutures which may be used in surgery, whereby it is important that the sutures prepared from polyglycolic acid are packed in dry conditions and that during storage no moisture penetrates into the package; such moisture would attack the suture of polyglycolic acid and strongly reduce its usability. The invention is especially directed to finding a packaging material for electrodes whereby the packaging material can also be used to package welding flux, welding wires and backing-up strips or other comparable objects. Electrodes which do not have to meet special requirements are packed in cardboard boxes, as is available on the market, whilst electrodes which need to be stored under dry circumstances are packed in hermetically sealed cans. Therefore, the invention especially relates to a packaging material to package electrodes which up to now were stored in tins, said electrodes being of a type such as described in the British patent application No. 2,070,976, titled: "Process for production of a low hydrogen type covered arc-electrode". Low hydrogen covered electrodes are used for welding operations where high standards are set for the welding material in welded joints in structural steel kinds such as Fe E355 or Fe E450, such as are used in, for example, offshore oil and gas producing platforms. One of the standards to be met thereby is that the electrode to be used has a low moisture content, preferably a moisture content so low that the quantity of hydrogen in the welding metal is less than 5 ml per 100 g of melted down welding metal. Customary instructions in connection with thick-walled, rigid constructions require the redrying of coated electrodes at a temperature of 300°-400° C. when the electrodes are supplied in a package which is not completely moisture-proof. Further, it is necessary for coated electrodes to be stored in a dry atmosphere after the redrying treatment, which can be achieved, for example, in warm storage cabinets or tubes at a temperature of about 75°-150° C. It cannot be assumed that these instructions are carried out completely and accurately. These operations also cause important substantial labour expenses. The absorption of moisture by coated electrodes before welding of the electrodes may lead to an undesired high level of diffusable hydrogen, as a result of which the risk of cracks initiated by hydrogen is present in the heavy and rigid steel constructions mentioned above. A moisture-proof package which has been used so far in this field is a hermetically sealed can, but such a package of tinplate usually contains about 25 kg of electrodes; this corresponds to 400-500 electrodes, which cannot be processed within a time span of 4 hours by a welder. Therefore, it is necessary for the electrodes from such a can to be stored in the above-mentioned warm storage cabinets or tubes when the can has been open longer than 4 hours. Efforts have been made, therefore, to find a material for a package unit which contains such a number of electrodes as a welder will use within four hours, and the package covers the electrodes and maintains the low moisture content the electrodes originally have in the unopened package. During long storage in the package the moisture content of the packed electrodes should not increase. This will do away with drying and warm storage before use of the electrodes if the electrodes are used within a few hours, viz. within about 4 hours after the package has been opened. Another problem which occurs when electrodes and the like are packed in a package which must contain relatively heavy electrodes is the mechanical strength of the packaging material that provides moisture-proof storage. These requirements with regard to the mechanical strength are of no influence or play hardly any role with the packaging material which is described in British Pat. No. 1,263,217 in which a packaging material is disclosed to package sutures moisture-proof. SUMMARY OF THE INVENTION This problem is now solved with a packaging material according to the invention; said packaging material is characterized in that an aluminum foil is applied on a creped basic layer of a plastic material or paper, said foil being provided with a protective layer. From the British patent specification it is known that aluminum foil is water-impermeable, but the mechanical strength in the packaging material according to the invention is obtained by applying such an aluminum foil on a creped basic layer; the packaging material has a relatively high deformability in the longitudinal direction and is for this reason not easily damaged. It also is important that the aluminum foil does not directly contact the electrodes, because the aluminum foil would be quickly damaged by the irregular structure of the electrodes. According to the invention, therefore, the aluminum foil is protected by the basic layer at the inside and by a protective layer, such as a plastic material, at the outside. Very thin aluminum foil already provides sufficient moisture-impermeable action, but the thinner the foil the larger the chance of "pin-holes" being present in the foil. Therefore, it is preferable to process two relatively thin aluminum foils into the packaging material, so that the chance of two "pin-holes" being located on each other is neglectably small. Because of the elastic properties of the present packaging material there will be no cracks in the aluminum foil, not even at those places which are most sensitive to the formation of such cracks, viz. the edges in the package where the outer ends of the electrodes are in contact with the package. The creped basic layer may be produced from a plastic material such as polyethylene or polypropylene, which may then be coated with an aluminum foil (not part of the creped basic layer itself) by gluing or the like. However, because the production of a creped layer of a plastic material is somewhat problematic, it is preferable to apply the aluminum foil on crepe paper, which in turn is coated with a plastic layer, such as a layer of polyethylene or polypropylene. DESCRIPTION OF THE INVENTION In the following description it is assumed that creped paper is used for the basic layer and polyethylene for the plastic material. With reference to a packaging material with a core of crepe paper the crepe paper is provided on both sides with an adhesive layer of polyethylene coated with an aluminum foil on both sides. On the inside, the aluminum foil is covered with polyethylene so that the electrodes cannot damage the aluminum foil and is also provided with a further polyethylene layer with which the package can be sealed or closed. On the outside of the package, the aluminum foil is provided with a protective layer so that the package is resistant against undesired mechanical influences from outside. BRIEF DESCRIPTION OF THE DRAWING The FIGURE diagrammatically illustrates a packaging according to the invention, with one electrode shown within the package. In the FIGURE, reference number 1 indicates the package and 2 indicates the electrode, which electrode has a holder end 3 and a starting head 4. The package also has a sealed seam 5 and a tear-open notch 6 on the package. As used herein the phrase "area density," applied to a sheet of material of predetermined thickness, indicates the mass per unit area (e.g., expressed in units of grams per square meter) of the sheet. A preferred embodiment of the packaging material is built up from the inside to the outside from: 90-110 g/m 2 (area density) sealing film of polyethylene, 100-120 g/m 2 protecting layer of polyethylene, 50-60 g/m 2 aluminum foil, 40-50 g/m 2 adhesive or protecting layer of polyethylene, 60-80 g/m 2 creped paper with 40% stretch (40% creping), 30-50 g/m 2 adhesive or protecting layer of polyethylene, 20-25 g/m 2 aluminum foil, 20-25 g/m 2 protective layer of polyethylene and 20 μm thickness transparent polyethylene film. In one an example according to the invention the package according to the invention is built up from: a sealing film of polyethylene with a thickess of about 110 μm of area density 90 g/m 2 ; for this purpose polyethylene with a low density may be used with 5 weight percent of vinylacetate (melting index according to ASTM D 1238 of 5.5 g/10 minutes and a volume density according to ASTM D 1505 of 0.922 g/cm 3 ); a protecting layer of polyethylene having a thickness of about 115 μm of area density 100 g/m 2 ; as such a foil one can use low density polyethylene such as having a melting index according to ASTM D 1238 of 8 g/10 minutes and a volume density according to ASTM D 1505 of 0.915 g/cm 3 ; an aluminum foil with a thickness of 20 μm of area density 55 g/cm 3 ; a coating of polyethylene with a thickness of 50 μm of area density 45 g/cm 3 ; a layer of crepe paper of area density 60 g/m 2 with 40 percent total stretch; a coating on the basis of polyethylene with a thickness of 50 μm of area density 40 g/cm 3 ; an aluminum foil with a thickness of 11-13 μm of area density 22 g/cm 3 and a protective layer or coating of polyethylene being 20 μm of area density 20 g/m 2 , and, if desired, a further transparent polyethylene film being 20 μm thick. The purpose of the inner layers of polyethylene with a total thickness of about 225 μm is to protect the aluminum foil from the comparatively rough surface of the electrodes so that the aluminum foil is not perforated. In the method according to the invention for packaging electrodes in a packaging material, the material is supplied to a packing unit as an upper and lower layer, the electrodes are positioned on the lower layer, the upper layer is provided and the upper and the lower layers are adhered together and the package is cut off at package length. The two layers are preferably at first adhered together in a limited number of spots to maintain their form and a vacuum is generated. The package is preferably sealed and the sealed seam is cooled. Subsequently the package is cut off at package length. In particular the upper and lower layers are stressed and pre-formed in a pre-heated die so that electrodes can be provided to fit therein. The electrodes typically have a length of 350-450 mm and a core diameter of 2.5-6 mm, around which a ceramic mass with a diameter of 4-13 mm is provided, and are maintained at a temperature of about 40° C. before being packed. Especially, the starting heads of the electrodes must be protected from shocks. Before packing the packaging material is supplied from reels, viz. one reel for supplying the upper layer and one reel for supplying the lower layer. During unwinding of the packaging material, both the lower layer and the upper layers are kept under tension, which tension is also maintained when the sheets of the packaging material are not moving. During the stationary position the upper and lower layers are pre-formed in a heated die. The pre-formed upper and lower layers together can be formed into a tube with a height varying from 7 to 25 mm, dependent on the number of layers and the thickness of the electrodes being packed. By means of pusher rolls the upper and lower layers are brought together after the electrodes have been provided on the lower layer. As soon as the upper and lower layers are in contact with each other they are spot-sealed on several spots so that the form of the tube is maintained. The ends of that tube are pressed flat and the tube is placed in a vacuum cabinet in which a vacuum of 60-90 percent of one atmosphere is generated so that in the vacuum cabinet there is a pressure of 0.1-0.4 atmosphere. In the vacuum cabinet the tube is completely sealed and the sealed seam is cooled, or the upper and lower layers are adhered together in a different manner. Subsequently the tube is removed from the vacuum cabinet and cut off at package length so that a package with electrodes according to the invention has been obtained. The sealed seam is obtained as a continuous seam without overlapping, so that the best possible connection of the upper layer to the lower layer is obtained. Sealing or adhering takes place by heating the layers of the packaging material at the outside of the package, whereby within a time of about 4 seconds a temperature of about 180° C. is obtained, dependent on the composition of the polyethylene comprising adhesive layer. During sealing the lower layer and the upper layer are pressed together at the outer adge. In such a tube preferably 1-5 layers of electrodes may be provided above one another; such a package usually has a weight of about 1-4 kg. It will of course also be possible to pack one single electrode in this way; such a packed electrode will fall within the scope of the present invention as long as a packaging material is used as recited in the following claims, or that a method is used as recited in the claims. When using the packed electrodes according to the invention it will be possible to check whether the package still meets the requirements; in other words, whether the electrodes still meet the requirements of "freshness" because before using the package it can be checked whether or not there is still a sub-atmospheric pressure inside the package. As long as there is still a sub-atmospheric pressure, it will be obvious that no leakage has occured.
Packaging material for relatively rigid objects, the material consisting of a metal foil sheet coated on one face of the foil sheet with a layer of plastic material, where a creped basic layer of a plastic material or paper is applied to a second face of the foil sheet.
8
This invention was made under National Institutes of Health grants 5ROI GM 28925 and 5ROI GM 24688. GENERAL DESCRIPTION OF THE INVENTION This invention relates to novel recombinant plasmids for the enhanced expression of an enzyme, to the preparation by gene cloning of such plasmids, to bacterial strains containing said plasmids, to methods for the conditional control of the expression of said enzyme and a method for the purification of said enzyme. The prior art has failed to clone polA, the structural gene which codes for DNA polymerase I (Pol I), onto a multicopy plasmid because the resultant increase above the natural level of expression of Pol I was known to be lethal to a host bacterium (Kelley, W. S., Chalmers, K. and Murray, N. E. (1977), Proc. Natl. Acad. Sci. U.S.A. 74, 5632-5636). In accordance with the present invention a novel recombinant plasmid has been developed and transformed into a host bacterium (E. coli) to produce a strain whose expression of DNA polymerase I is subject to experimental control. Growth conditions are selected to enable the host to express conditionally a greatly enchanced level of DNA polymerase I, even though a lesser enhancement of this enzyme is normally lethal to the host. The growth control conditions produce a broth which is benefited by an improved DNA polymerase I purification scheme. Through the improved purification scheme, Pol I is recovered in relatively high yields of greater purity (specific activity) and stability and with relatively short purification time requirements as compared to prior art purification methods. The novel recombinant plasmid for the production of DNA polymerase I is plasmid pMP5. The viable E. coli strain containing this plasmid is ATL100, which was deposited in the American Type Culture Collection Depository on June 29, 1984, under Accession number 39753. The microorganism so deposited is available to the public and will remain so for the life of this patent. The novel plasmid can be separated from the deposited host microorganism by conventional methods known to the art. An article entitled "Construction of a plasmid that overproduces the large proteolytic fragment (Klenow fragment) of DNA polymerase I of Escherichia Coli" by C. M. Joyce and N. D. F. Grindley (1983) Proc. Natl. Acad. Sci. U.S.A. 80, pp. 1830-1834, teaches the construction of plasmids which direct the overproduction of the carboxyl-terminal two-thirds of DNA polymerase I, known as the Klenow fragment of the enzyme. The Pol I molecule can be split into two enzymatically active fragments, a large fragment and a small fragment. The large or carboxylterminal fragment (the Klenow fragment) contains the polymerase and 3'-5' exonuclease functions whereas the smaller fragment contains the 5'-3' exonuclease activity necessary for the nick-translation reaction of Pol I. The article by Kelley, Chalmers and Murray teaches that the polA gene could not be stably maintained on a multicopy plasmid. Therefore, Joyce and Grindley began their construction with a mutation of the polA gene located amino terminal to the Klenow fragment coding region. The polA gene was then further mutated by the removal of the portion of the gene upstream of the Klenow fragment so that the promoter was by necessity also removed with the gene fragment. The remaining portion of the polA gene, containing the coding region for the Klenow fragment, was fused to translational control signals and cloned downstream of a lac or phage lambda promoter, both of which are more active than the natural promoter of the polA gene. Thereby, a plasmid was produced capable of overproducing only the Klenow fragment of the Pol I molecule. The present invention is directed to a novel plasmid containing the entire nonmutated structural gene coding region for the production of the complete Pol I enzyme, including both the Klenow fragment and the smaller fragment. As stated above, the smaller fragment is necessary for the nick-translation reaction of Pol I. The nick-translation reaction of Pol I is an extremely useful reaction because it is universally used to insert into DNA selected nucleotide bases which are radioactively or otherwise tagged and serve as DNA probes. DNA probe-based diagnostics for cytomegalovirus, Epstein-Barr virus, hepatitis B virus and herpes virus are currently being produced commercially for scientific and medical laboratories. The novel plasmid of the present invention contains the entire and undamaged polA gene coding region enzymatically excised from a DNA molecule. However, it is an important feature of this invention that the cloned polA gene fragment contains essentially none of or at the most only a portion of the activity of its natural promoter. For instance, the natural promoter could be rendered less active by removing at least a portion thereof or by introducing the novel plasmid into a heterologous host where the natural promoter has reduced activity. The promoter is a transcriptional control element in a DNA molecule that regulates the expression of the gene and is adjacent to the gene. The cloned polA gene is fused enzymatically to a foreign promoter whose activity is subject to conditional control and which will be less active than the natural polA promoter under environmental conditions where the foreign promoter is in its non-activated state. We have discovered that the restriction enzyme BglII will cut within the polA promoter sequence and severely damage it. This is a significant discovery of the present invention, since it eliminates or greatly reduces the unregulated expression of Pol I, which would otherwise be lethal to the cell. Had this not been the case, BglII cutting of polA DNA could have been used, followed by treatment with exonuclease BAL-31 to inactivate the polA promoter. An exonuclease such as BAL-31 will carry out step-wise removal of individual nucleotides, eventually giving removal of all or part of the natural promoter. Examples of tightly controllable and potentially more active foreign promoters include the lac promoter, the trp promoter and the leftward promoter p L of phage lambda, all of which are subject to "negative" or repressible control. If desired, the foreign promoter can be subject to "positive" or activator control. Examples of such promoters are the mal promoter and the late promoters of bacteriophage T 7 . The active promoter can be native to the vector plasmid or can be cloned into the vector plasmid from a foreign source. When a plasmid chimera containing the clored complete and undamaged polA gene coding region with at least a portion of its natural promoter removed and provided with a foreign and more powerful promoter is transformed into a host bacterium, the plasmid tends to express an amount of Pol I which is lethal to the host strain or at least inhibitory of cell growth in the host strain. In general, the expression of Pol I above the natural amount is lethal, debilitating or inhibitory to cell growth in a host stain. However, as indicated above, the foreign promoter can be chosen such that its activity is subject to conditional control. Therefore, when the host bacterium receives the novel plasmid of this invention it is maintained under environmental conditions which fail to activate or which "repress" substantially entirely, or to a major extent, the activity of the promoter and under which the cells can multiply substantially normally to produce an enlarged population of cells in which the novel plasmid is replicated. While continuing to repress the foreign promoter, or in the case of a positively regulated promoter not inducing activation of the activity of the foreign promoter, the cells are cultured in a nutrient broth to induce cell multiplication and produce an enlarged cell population containing the replicated novel plasmid. This cell multiplication occurs essentially without an enhanced expression of Pol I. Thereupon, the conditions of promoter repression are "switched" off or the conditions of activation are switched "on", and the foreign promoter is permitted to influence the polA gene to express an enhanced yield of Pol I. After a limited period of such expression, the cells die or become delibitated or growth inhibited. The only surviving or multiplying cells are a subpopulation of natural mutants which do not express an excess quantity of the enzyme. Because of the enlargement of the culture containing the replicated novel plasmid, and the enhanced level of polA expression resulting from the induction of the foreign promoter, the harvestable amount of DNA polymerase I produced by an E. coli host is about 138 times the amount of Pol I produced by wild type E. coli K12. This degree of amplification is remarkable when compared to the current commercial source of Pol I, strain CM5199, which is typically capable of only a 17-fold amplification over wild type K12. The present invention can be performed using temperature as the environmental factor which controls expression of Pol I. For example, a polA coding region can be cloned downstream from the leftward p L promoter of phage lambda, and control over p L activity then provided via a temperature sensitive phage lambda cI gene product (repressor). In this case, the cell colony is cultured in a nutrient broth at a temperature equal to or below 32° C., at which temperature expression of polymerase is repressed, but the cell colony grows. After the cell colony has grown sufficiently, the temperature "switch" can be changed to 42° C., at which temperature a high yield of Pol I is expressed until the cells stop growing after about 40 minutes. Examples of other environmental factors that can be employed include osmotic pressure and chemical inducers of de-repression, each of which can be employed as an on and off mechanism analogous to the temperature switch. An example of a chemical inducer is IPTG (isopropyl-β-D-thiogalatopyranoside), which binds to and turns "off" the lac repressor. A positively regulated promoter can also be turned off and on by environmental factors. Examples are the mal promoter which can be switched on by the addition of the carbohydrate maltose to the growth medium, and the late promoters of bacteriophage T 7 which are utilized only by the virus' own RNA polymerase. T 7 RNA polymerase can be provided by infecting cells with the virus or by co-cloning of its gene under conditions where it too is subject to conditional control. This invention can be applied in a similar manner to plasmids containing a whole undamaged structural gene coding region for an enzyme or protein other than Pol I having its natural promoter partially or entirely removed or otherwise rendered inactive and which is fused to a tightly regulated foreign promoter. This invention will be of utility specifically in those instances, such as with polA, where expression from the natural promoter of the gene of interest is not tightly regulated and where cloning of the intact structural gene onto a high copy number plasmid is impossible because of a lethal or debilitating overproduction of the corresponding gene product. Such other plasmids can be transformed into a host microorganism, such as E. coli, and cultured in a nutrient broth in which they multiply and replicate the plasmid under the influence of an active repressor or an inactive activator for the foreign promoter. When the lambda leftward promoter is used an effective repressor is the temperature sensitive cI857 repressor. This repressor is of a type which can be "switched" off by temperature inactivation after the culture has grown to allow the enlarged cell population within which expression of the enzyme from the cloned gene is induced to effect a yield of the cloned gene's product which is greatly enhanced compared to the wild type yield and which would be lethal, debilitating or growth inhibiting to the host. We have developed a novel method for the purification of Pol I produced by the method of this invention, which is capable of harvesting 10 to 15 weight percent of the available Pol I in a period of about 21/2days, which is both a high recoverable yield and a short purification duration compared to prior methods. For example, present separating procedures require about a week. The novel method is applied to the bulk crude extract, rather than to aliquot portions. A novel feature of the present purification method is the removal of DNA prior to salt precipitation of Pol I. It is known that in the presence of a high level of DNA, protein remains suspended in high salt precipitations and must be filtered because it does not effectively pellet out by centrifugation. We have discovered that if DNA is removed prior to high salt precipitation of Pol I, the Pol I is effectively recovered as a pellet by centrifugation. A crude extract can be prepared for the novel purification method by sonication of the polymerase-containing cell suspension in bulk followed by centrifuging to remove cell debris, yielding a supernate containing DNA polymerase I, together with other proteins and DNA. In the present system, some DNA precipitates with protein in the polyethyleneimine precipitation step. It is a novel feature of this purification method that this DNA is removed by means of an ion exchange resin, which retains DNA, in advance of the salt precipitation steps of the procedure. Since DNA is negatively charged, it adheres to an ion exchange resin having positive charges. If the DNA is not removed prior to these salt precipitation steps and a significant quantity of DNA is present, the polymerase will remain suspended during the high salt precipitation step and will not be removable as a pellet in the centrifugation operation following the high salt precipitation step. Although the suspension can be removed by filtration, it is an advantageous feature of the present procedure that centrifugation can remove the polymerase as a pellet, as described in the following procedure. The DNA polymerase I purification method of this invention comprises in sequence: (a) subjecting the crude extact to a series of treatments with polyethyleneimine each followed by centrifuging with the polyethyleneimine being present in increasing concentrations in the series of steps to precipitate acidic proteins together with some DNA and form polyethyleneimine pellets containing various concentrations of polymerase activity (units/mg); (b) extraction of the polyethyleneimine pellets of relatively high polymerase activity with a buffer and contacting said soluble polyethyleneimine pellet extracts with an ion exchange resin such as diethylaminoethyl cellulose, which retains DNA, and recovering an eluate having DNA removed; (c) treating said eluate having DNA removed with a salt for the precipitation of proteins in relatively low concentration and centrifuging to produce a supernate, and then treating the supernate with the salt in a relatively high concentration and centrifuging to produce a protein pellet, the salt used being ammonium sulfate, preferably, and calcium chloride, less preferably; (d) dissolve said protein pellet in a buffer followed by dialysis to remove salt from protein; and (e) passing said soluble dialyzed protein over an ion exchange resin for the retention of DNA polymerase I and subsequently deionizing said resin to recover ion exchange fractions of high polymerase activity. These fractions are the high activity DNA polymerase product of the procedure. An outline of the polymerase purification procedure is presented in FIG. 3. Prior purification methods for the recovery of polymerase from a system wherein it has been amplified have encountered considerable difficulty because while the polymerase is being greatly amplified, nucleic acids and other proteins are also being amplified making the purification of the polymerase very difficult. It is an important feature of the present system that the DNA is removed from the system before the polymerase salt precipitation step. When the present Pol I amplification method is combined with the present purification method, the recovered polymerase has a higher specific activity than any yet reported, i.e. 32,000 units/mg vs. 18,000 units/mg for the prior art. DESCRIPTION OF THE PREFERRED EMBODIMENTS This following discloses the construction of plasmid pMP5 which contains both the coding sequence for DNA polymerase I with a damaged polA promoter, and the bacteriophage lambda p L promoter for conditional control of the polA gene expression. Transformation of pMP5 into E. coli N4830 yields strain ATL100 which under inducing conditions provides a 138 fold amplification of DNA polyerase I. The plasmid pMP5 was constructed as a derivative of the p L expression vector pHUB2 (Bernard H.-U. Remault, E. Hershfield, M. V., Yanofsky, C., and Franklin, N. (1979) Gene 5, 59-76) using the transducing phage NM825 (Murray, N. E., and Kelley, W. S. (1979) Mol. Gen. Genet. 175, 77-87) as a source of polA + . pHUB2 DNA was digested with BamHI and SalI and ligated to DNA of NM825 cut with BglII and SalI (FIG. 1) This DNA was transformed into strain XK603 and kanamycin-resistant, tetracycline-sensitive clones identified. Strains containing apparent inserts into pHUB2 were assayed for DNA polymerase I levels after growth and heat induction of expression from p L . Strain XK603 contains a heat-inducible lambda prophage whose cI857[Ts]repressor gene provides the conditional control over the plasmid's p L promoter. The plasmid pMP5 was detected by its ability to greatly overproduce DNA polymerase activity upon temperature inactivation of the resident phage cI857 repressor and the purified plasmid DNA had the expected size and restriction endonuclease cleavage pattern. Strain ATL100 was constructed by transforming plasmid pMP5 into E. coli strain N4830 with selection for kanamycin resistance. Strain N4830 contains a defective lambda prophage, including a cI857[Ts] gene, and gives constitutive expression of the lambda N gene product at the inducing temperature (Gottesman, M. E., Adhya, S. and Das, A. (1980), J. Mol. Biol. 140, 57-75). Growth of ATL100 - A standing overnight culture of ATL100 at 28° C. was started by inoculating 15 ml of L broth (L broth contains per liter: 10 g tryptone, 5 g yeast extract, 10 g NaCl) containing 50,μg/ml kanamycin and 0.2% glucose with a 1 ml frozen sample of ATL100 that was previously prepared from a culture showing a high ratio of small to large colony formation. Under these growth conditions the 15 ml overnight culture routinely grew to a Klett value of 100 in a 24 hr period. A second overnight culture was then started in L broth containing kanamycin and 0.2% glucose by inoculating 3×500 ml cultures each with 5 ml from the previous standing overnight culture and allowing these to grow at 28° C. with slow shaking (approx. 90 rpm) to a Klett value of 100. The 3×500 ml cultures were then used to inoculate a 28 L fermentor (New Brunswick Microferm) containing 20 1 of L broth with kanamycin and 0.2% glucose. The cells were grown at 28° C. until they reached a Klett value of 100 at which time a slow temperature induction was started by increasing the temperature to 42° C. over a 40 min. interval. The culture was then allowed to grow at 42° C. for an additional 10 min. Fifty minutes after the start of induction, the fermentor was quickly chilled to 20° C. and the cells harvested by centrifugation. The cell paste was collected and stored frozen at -50° C. Polymerase Purification--All steps of the purification were carried out at 4° C. Frozen cells, stored at -50 ° C., are thawed and resuspended (3-4 ml/gm cells)in 50 mM Tris-Cl, pH 7.6, buffer containing 2 mM EDTA and 1 mM dithiothreitol (DIT). The suspension is sonicated in a Bronson Sonifier, Cell Disrupter 200, at a setting of 10 for 5 minute pulses with the sonication vessel immersed in an ice water bath. Absorbance of the suspension is monitored at 550 nm to determine the extent of lysis after each pulse. Generally, maximal lysis required 15-20 minutes total sonication. The final suspension is centrifuged at 17,300×G for twenty minutes. The supernate is designated as the crude extract. Polymin P titration--A 10% (v/v) solution of Polyethyleneimine (Polymin P, PEI (Miles Laboratories)), titrated to pH 7.6 is added to the supernate to a final concentration of 0.2%. The suspension is allowed to stand 30 minutes at 4° C. and centrifuged at 17,300×G for 15 minutes. The pellet is saved and the PEI concentration of the supernate is raised to 0.4%. After 30 minutes the suspension is again centrifuged, the pellet saved, and the procedure repeated at 0.2% PEI intervals until the supernate remains clear after PEI addition. All pellets are saved at -20° C. until polymerase assays are performed on aliquots from each of the individual PEI supernates saved during the titration. DEAE-Cellulose Chromatography--PEI pellets containing the maximum polymerase activity are combined, resuspended in onethird the original volume of a buffer containing 20 mM K·PO 4 , pH 6.5, 2 mM EDTA, 2 mM DTT, and 0.2 M (NH 4 ) 2 SO 4 . The suspension is homogenized and centrifuged at 17,300×G for 15 minutes at 4° C. The extraction is repeated twice more and the supernates are combined and designated as the PEI resuspension (Table 1). This resuspension is loaded directly onto a 5×30 cm DEAECellulose (DE-52, Whatman) column equilibrated and run in a 0.2 M K·PO 4 , pH 6.5 buffer containing 1 mM DTT. Under these conditions, pol I elutes from the column in the breakthrough volume. The absorbance at 280 and 260 nm is measured and fractions with a 280/260 ratio greater than 1.0 are combined. Using this criterium, pol I assays of DEAE fractions from several preparations have shown that greater than 90 % of the pol activity is recovered from the column in these fractions. This sample is designated as the pooled DEAE fractions (Table 1). Ammonium Sulfate Fractionation--The pooled DEAE fractions are brought to 40% saturation in (NH 4 ) 2 SO 4 at 4° C., allowed to equilibrate 30 minutes and centrifuged at 17,300×G for 15 minutes. The supernate is raised to 80% saturation in (NH 4 ) 2 SO 4 at 4° C., allowed to stand 2-3 hours, and centrifuged at 17,300×G for 15 minutes. At this point the pellet can be saved frozen at -20° C. Bio-Rex 70 Chromatography--The 80% (NH 4 ) 2 SO 4 pellet is resuspended in a 100 mM K·PO 4 , pH7.0, buffer containing 1 mM DTT, and dialyzed against 2×2 liter changes in the same buffer for 2 hours total. The dialyzed, resuspended pellets are adjusted to the conductivity of the column buffer with cold deionized water and loaded onto a 2.5×15 cm Bio-Rex 70 (Bio-Rad) column equilibrated in 50 mM K·PO 4 pH7.0, buffer containing 1 mM DTT. The column is washed until the absorbance at 280 nm returns to baseline following the flow-through material and then a linear gradient to 0.5 M NaCl in 50 mM K·PO 4 , pH 7.0, buffer containing 1 mM DTT (600 ml total volume) is applied. Fractions (12 ml/fraction) are monitored for absorbance at 280 nm, conductivity, and polymerase activity. A 10% SDS polyacrylamide gel is run on fractions containing polymerase activity and fractions are pooled based on maximum activity and minimum protein contamination. Pooled fractions are stored either at 4° C. with 10 mM DTT or at -50° C. after dilution to 50% glycerol and addition of DTT to 10 mM. Miscellaneous Methods--DNA polymerase I assays were performed (Kelley, W. S., Chalmers, K., and Murray, N. E. (1977) Proc. Natl. Acad., Sci. U.S.A. 74, 5632-5636) using nicked calf thymus DNA (Richardson, C. C. (1966) in Procedures in Nucleic Acid Research (Cantoni, G. L. and Davies, D. R. eds.) Vol. 1, pp. 212-223, Harper and Row, New York) or d(AT) copolymers as primer/template. Protein concentration was determined both by the Lowry method (Lowry, O. H. Rosebrough, N. J. Farr, A. L. and Randall, R. J. (1951) J. Biol. Chem. 193, 265-275) using bovine serum albumin as the standard, and by quantitative amino acid analysis on a Durrum D-500 analyzer. Protein analysis by electrophoresis was performed on 10% acrylamide gels under reducing conditions in the presence of sodium dodecyl sulfate according to the procedure of Laemmli (Laemmli, U.K. (1970) Nature 227, 680-685). Optimizing expression of DNA polymerase I--Growth of ATL100 is extremely slow at non-inducing temperatures, with a doubling time (t D ) of 120 minutes in L broth at 32° C. This is consistent with the strain making very small colonies after overnight growth on L broth plates. Surprisingly, shifting a broth-grow culture of ATL100 to the inducing temperature (42° C.) resulted in a transient cessation of growth followed thereafter by an acceleration of the growth rate until it reached t D of 60 min. The level of DNA polymerase increased abruptly upon shifting to the inducing temperature, attaining its maximal specific activity within 40 to 50 min. Thereafter, however, polymerase specific activity gradually declined, while the culture continued to grow (FIG. 2). This rather curious cell growth versus polymerase specific activity behavior led us to plate out samples of the culture from the kinetic experiment for viable counts. It has now been discovered that large-scale cultures of ATL100 actually contain two colony types, one of which is very small after overnight growth, the other larger and more normally sized. A typical large scale growth of ATL100, would show a continual decline in the ratio of small to large colonies. For example, the ratio is approximately 70 after the first overnight incubation, 20 after the second overnight incubation, 9 at the time of induction in the fermentor, and 1 to 2 following 300 minutes of growth after induction. A kinetic experiment using a culture derived from the large colony type showed that such a culture continued to grow after shifting to the inducing temperature (t D of 60 minutes) but did not produce elevated levels of DNA polymerase. The presence of these two colony types thus explains the observed patterns of cell growth and polymerase specific activity. The small colony type over-produces DNA polymerase and does not grow at the inducing temperature whereas the large colony type is non-producing and, by continuing to grow, dilutes polymerase specific activity when it becomes predominant. Three independent experiments were made to explore the possible relationship between the ratio of small to large colonies in the uninduced culture, and the level of DNA polymerase I obtained after induction. There was found to be a positive correlation between the two, with a small to large colony ratio of approximately twenty being indicative of a near maximal amplification. We have consistently observed the appearance of the large colony type when working with ATL100, even when we inoculate cultures from purified single colonies of the small variety. Thus, there is a clear implication that pMP5 is only marginally tolerated by N4830 and that during growth and/or maintenance of pMP5-containing strains there is a continual selection of plasmid derivatives which no longer produce DNA polymerase, even under ostensibly non-inducing conditions. For this reason, sub-culturing of ATL100 is avoided, and starter cultures are stored frozen. Rapid Purification of Pol 1--The purification scheme of this invention both increases the yield and decreases the time of purification over other prior art purification schemes. As stated above, the overall procedure takes two and one-half days and yields 10--15% of the total available polymerase. Traditionally, the PEI titration is performed on an aliquot of the crude extract to determine the appropriate PEI concentration for precipitation of the bulk material. In contrast, the present titration was performed on the whole crude extract. The individual pellets from each PEI precipitation step were stored frozen at -20° C. while polymerase assays were performed on samples of the individual supernates saved during the titration. Appropriate pellets were then chosen for combination based on the loss of polymerase activity from the corresponding supernatant fraction. The major change from previous protocols occurs at the next step. It was found that DNA apparently interfers with the high salt (NH 4 ) 2 SO 4 fractionation (i.e. the 80% cut remains suspended after centrifugation). Therefore, the step involving DEAE-Cellulose removal of DNA was placed before the (NH 4 ) 2 SO 4 fractionation. In this case, the PEI resuspension is placed directly on the DEAE-Cellulose column and 80-90% of the polymerase is eluted from the column before the A 280/260 ratio drops below 1.0. The DEAE elution is followed directly by ammonium sulfate fractionation which yielded a clear supernate after centrifugation of the 80% cut. DESCRIPTION OF THE DRAWINGS The present invention can now be illustrated by the figures in which: FIG. 1 illustrates cloning of polA + onto a plasmid expression vector. Phage NM825 carries the polA + gene (solid dark region) in the left-to-right orientation, as indicated by the arrow extending from the amino (N) to the carboxyl (C) terminus. An att-red deletion in the phage vector's right arm brings the right hand HindIII site into close proximity with the lambda SalI site near gam. The expression vector pHUB2 carries the lambda promoter p L oriented for transcription towards the plasmid's tet gene, as indicated by the arrow. FIG. 2 illustrates growth of and polymerase production from ATL100. Cell density and polymerase specific activity from crude extract aliquots are presented over the time course from 220 minutes prior to induction, through induction at 0 time from either 28° C. or 32° C. to 42° C. to 300 minutes beyond induction. In this case, rapid induction (2° C./min) to 42° C. was performed and cells harvested at 50 minutes from the 28 liter fermenter under these conditions were used in the purification scheme described in Table I. TABLE I______________________________________Analysis of Purification Scheme Spec. Act % YieldSAMPLE mg PROT..sup.a (units/mg).sup.b (units)______________________________________Crude Extract 2051 2,000 100.sup.cPEI Resuspension 728 1,658 29.4Pooled DEAE 528 2,092 26.9Fractions40% Ammonium Sulfate 368 3,647 32.7SupernateDialyzed, Resuspended 344 3,028 25.580% Amm. Sulf. PelletBioRex Fractions 16.2 30,162 11.9(42-44)______________________________________ .sup.a Protein concentration determined both by Lowry protein assay (J. Biol. Chem. 193, 265-275) and by quantitative amino acid analysis. Result from these methods differed by less than 10%. .sup.b Polymerase activity was determined using nicked calf thymus DNA as substrate (J. Biol. Chem. 275, 1958-1964). .sup.c Yield of Pol I from crude extract was arbitrarily set at 100%. 3.1 × 10.sup.6 units were measured in the crude extract from 63 grams o cells. FIG. 3 is a schematic diagram illustrating the purification scheme in detail.
Restriction enzymes are used to remove from DNA a complete and undamaged structural gene coding region for the expression of DNA polymerase I (polA) without the gene's natural promoter or with only a significantly damaged portion of the gene's natural promoter. Also by the use of restriction enzymes, a segment from a plasmid cloning vector is excised at a position adjacent to a promoter which is conditionally controllable and may be more powerful than the damaged or removed promoter. The gene for DNA polymerase I is enzymatically cloned into said vector at the position of said removed segment and adjacent to said conditionally controllable promoter. Multicopies of the cloned vector are introduced into a host baterial strain (E. coli). The host strain is then cultured so that the cell colony grows and replicates new generations containing replicated foreign plasmid. During such said replication the activity of said controllable promoter is repressed. After the cell colony has grown, the repression of said controllable promoter is removed and the cells express an amplified amount of DNA polymerase I which is lethal or inhibitory to the cells. An improved procedure is disclosed comprising a sequence of steps for harvesting purified DNA polymerase I.
2
[0001] This nonprovisional application is a continuation of International Application No. PCT/EP2010/068227, which was filed on Nov. 25, 2010, and which claims priority to German Patent Application No. DE 10 2009 055 715.6, which was filed in Germany on Nov. 26, 2009, and which are both herein incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention concerns an intake manifold with an integrated charge air cooler. [0004] 2. Description of the Background Art [0005] From the practice of motor vehicle construction, proposals are known for integrating charge air coolers into an intake manifold of an internal combustion engine, wherein the charge air cooler is cooled indirectly, which is to say with coolant flowing through it. It is customary in this context to provide the charge air cooler with a flange plate, so that it can be inserted in an opening of an intake manifold housing in the manner of a plug-in unit and the edge of the flange plate can be screwed or welded to the housing. With this type of construction, vibrations or thermally caused distortions are transmitted directly to the charge air cooler via the flange plate. SUMMARY OF THE INVENTION [0006] It is therefore an object of the invention to provide an intake manifold with an integrated charge air cooler, in which the charge air cooler is especially well protected from vibrations and distortions. [0007] Because the charge air cooler is essentially fully enclosed by the housing, it can be accommodated in the housing in a sufficiently damped manner. The required feed-throughs for the coolant have a relatively small cross-sectional area and can be sealed with respect to the housing by suitable devices such that no significant forces from vibrations or thermal distortions are transmitted to the charge air cooler. In accordance with the invention, the charge air cooler is elastically supported with respect to the housing. In this way, vibrations that are first transmitted from the internal combustion engine to the housing are damped with respect to the charge air cooler, or the charge air cooler and the intake manifold housing are decoupled. In accordance with the invention, the support is accomplished by means of at least one elastic support member, which is located on a header of the charge air cooler in a detailed design that is preferred but not required. The support member may be composed of a block of an elastic material such as rubber or the like, for example, but this is not required. For example, fastening to the header can take place by means of clamping, possibly by means of a flexible tab of the header. The arrangement of the support member on the header has in particular the advantage that the support forces act on structures that are relatively insensitive mechanically. [0008] In general, charge air within the meaning of the invention is understood to mean the gas supplied to the internal combustion engine, and in this sense also includes any desired mixtures of air and exhaust gas if exhaust gas recirculation is provided. The intake manifold in accordance with the invention can be combined with diesel engines as well as with gasoline engines. [0009] In an embodiment of the invention, the charge air cooler has essentially the shape of a cuboid, wherein the charge air cooler can be inserted in one of the housing parts perpendicular to the largest side surface of the cuboid. This simplifies assembly of the intake manifold. In a detailed design that is preferred but not required, the charge air cooler is inserted from above. [0010] It is advantageous in general for the charge air cooler of an intake manifold in accordance with an embodiment of the invention to be designed as a tube heat exchanger with a stack of flat tubes, wherein the coolant flows through the flat tubes and the charge air flows around them. Such construction offers high cooling performance with low weight and a small installation space. In a preferred detail design in this regard, one header is located at each end of the flat tubes, wherein the flat tubes and the headers are manufactured as a soldered block from metal, preferably aluminum. In addition to the simple and economical manufacture, there are no seals between the coolant region and the charge air region in such a construction, so that the danger of a water hammer is reduced. In another preferred detail design, at least one of the headers has a base region and a header wall that are produced together as one piece from a formed sheet metal part. This reduces both the manufacturing costs and the number of soldered joints, resulting in an especially low reject rate. For example, it is possible to make a header from only three parts, namely the formed sheet metal part and two cover parts, and in another embodiment from five parts, namely the formed sheet metal part and a total of four cover parts. [0011] In another preferred detail design, the tube bundle includes at least two rows of tubes in a depth direction, so that multiple flow paths are available for the coolant and the heat exchanger performance can be optimized for a given installation space. In a preferred embodiment, the rows of tubes can includes separate flat tubes, and in an alternative preferred embodiment can include a one-piece flat tube with separate flow passages. Such a one-piece flat tube can be manufactured as an extruded part, for example. Furthermore, it is preferred for the coolant to flow through the rows of tubes sequentially in opposite directions, in particular in a counterflow configuration with regard to the direction of flow of the charge air. This optimizes the heat exchanger performance for a given installation space. In addition, in the case of a two-row heat exchanger with a redirection region at the end, for example, both coolant connections can be provided on the same header. [0012] In one possible embodiment of the invention, at least one side part is arranged on the charge air cooler, wherein the side part has a structuring for producing a labyrinth seal with respect to an inside wall of the housing. By this means, a leakage flow of the charge air between the charge air cooler and the housing wall is prevented in a simple way. A labyrinth seal is effective even if the housing wall forms bulges or similar deformations as a result of temperature variations. An elastomer seal can optionally be provided in addition to the labyrinth seal. [0013] In another embodiment, at least two support members are connected to one another via a coupling link. This makes installation easier and ensures retention of the support elements on the charge air cooler, either by itself or as an additional measure. In one preferred detail design, the coupling link has a sealing member to seal the charge air cooler with respect to the housing, so that sealing against such occurrences as leakage flows of the charge air around the charge air cooler can be accomplished at the same time. [0014] It is advantageous in general for a header of the charge air cooler to have an overhang extending in the flow direction of the charge air beyond an inlet plane or outlet plane of a cooler network. For instance, this form can produce improved or simplified sealing against leakage flows of the charge air, for example between the header and a housing wall. In particular, it is preferred for the overhang to be provided with a sealing member and/or to form a support for a sealing member. [0015] Depending on the requirements, the housing can be made of a plastic or a light metal, for example based on aluminum. [0016] It is preferred for an engine flange for attachment to an intake region of a cylinder head to be provided at the outlet of the housing, wherein the engine flange preferably can be made of plastic or a light metal in accordance with requirements. For optimizing the costs, provision can be made for the engine flange to be made of light metal while the housing of the intake manifold is made of a plastic, for example. In this case the engine flange and housing are fastened together as separate parts, for example by means of threaded fittings. If the engine flange and housing are made of the same material, such as plastic or aluminum, they can be designed as a single piece of uniform material. A single-piece design with uniform material also includes the case in which, for structural reasons, the housing and engine flange are prefabricated from plastic and are then welded together as separate parts, for example by means of ultrasonic welding. Alternatively thereto, the engine flange can be molded with the housing in a single casting operation if the shape allows for this in casting. [0017] In another embodiment, a coolant connection of the charge air cooler is elastically sealed in an airtight manner to the housing in the region of the feed-throughs. The elastic sealing reduces the transmission of distortions and vibration from the housing to the charge air cooler. [0018] In generally advantageous manner, provision can be made for at least one coolant connection of the charge air cooler to be joined material-to-material with the charge air cooler, in a preferred detail design by means of soldering, and/or for at least one coolant connection of the charge air cooler to be joined in an interlocking manner with the charge air cooler, in a preferred detail design by means of threaded fittings and/or clips. [0019] In an embodiment, at least one coolant connection of the charge air cooler is provided on a top side of the charge air cooler with respect to gravity. In this way, additional venting openings can be eliminated, since venting of the charge air cooler takes place automatically through its coolant connections. [0020] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0021] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein: [0022] FIG. 1 shows an exploded three-dimensional view of an intake manifold with an integrated charge air cooler according to the invention. [0023] FIG. 2 shows an exploded three-dimensional view of the charge air cooler from FIG. 1 . [0024] FIG. 3 shows a partially cut away, inverted three-dimensional view of the charge air cooler from FIG. 1 . [0025] FIG. 4 shows a partial cross-section of the charge air cooler from FIG. 1 . [0026] FIG. 5 shows a first variant of a housing part of the intake manifold from FIG. 1 with adjoining engine flange. [0027] FIG. 6 shows a second variant of the housing part from FIG. 5 with adjoining engine flange. [0028] FIG. 7 shows a three-dimensional view of a variant of the intake manifold from FIG. 1 with installed support members. [0029] FIG. 8 shows a three-dimensional view of the charge air cooler from FIG. 3 . [0030] FIG. 9 shows an enlarged cutaway view of the charge air cooler from FIG. 4 in the region of a header. DETAILED DESCRIPTION [0031] The intake manifold according to the invention shown in FIG. 1 comprises an outer housing 1 made of plastic, which comprises a bottom housing part la and a top housing part 1 b . The bottom housing part 1 a encloses the majority of the volume of the housing interior, and has an inlet 2 in the form of a tubular flange for connection to a charge air duct and an outlet 3 in the form of a rectangular opening that extends over the majority of one side wall. [0032] The second, top housing part 1 b is designed essentially in the shape of a flat cover with rib structures 4 provided for reinforcement. Reinforcing rib structures 4 are also located over all side walls of the bottom housing part 1 a. [0033] The installation position of the housing 1 relative to an internal combustion engine that is not shown corresponds essentially to the position in FIG. 1 . The parting plane between the housing parts 1 a , 1 b extends essentially horizontally. A charge air cooler 5 installed in the housing has essentially a cuboid shape that is essentially enclosed by the interior space of the housing 1 present between the housing parts la, 1 b . The largest side area of the cuboid extends horizontally and parallel to the parting plane between the housing parts 1 a , 1 b . As FIG. 1 shows, the charge air cooler 5 can be inserted in the bottom housing part 1 a perpendicular to the largest side area of the cuboid. Here, the orientation relative to the perpendicular relates to the installation position in the motor vehicle. It is a matter of course that the preassembly of the parts before installation in the motor vehicle can also take place in another spatial orientation. In the example according to FIG. 1 , the two housing parts 1 a , 1 b are screwed together in a sealing manner along an edge 1 c that is provided with holes. Alternatively, the parts can also be permanently welded or glued together. [0034] In order to avoid lateral leakage flow of the charge air, sides of the charge air cooler implemented as headers 11 , 14 are embedded in convex projections 1 d of the housing part 1 a , which projections form an undercut with respect to the housing in the region of the inlet 2 . Moreover, additional sealing devices that are not shown in FIG. 1 and FIG. 2 can be provided between the headers 11 , 14 and the side walls of the housing part 1 a or convex projections 1 d ; see the variation in FIG. 3 through FIG. 5 , for example. [0035] A first feed-through 6 for accommodating an inlet connection fitting 7 (see FIG. 2 ) for a coolant of the charge air cooler 5 is located in a bottom side of the bottom housing part 1 a . A second feed-through 8 for an outlet connection fitting 9 of the charge air cooler 5 is located in the cover-like top housing part 1 b . The connection fitting 9 is located on a top side of the charge air cooler 5 , so that no additional venting bores are provided on the charge air cooler 5 . Venting of the charge air cooler 5 with respect to the coolant flowing through it takes place without difficulty in the installed state and in operation through the upper coolant connection 9 . [0036] The charge air cooler 5 is designed entirely as a soldered block from aluminum parts. In a known manner, at least some of the parts are solder-plated on one or both sides and are soldered in a soldering furnace after mechanical preassembly and fixturing. [0037] In accordance with the exploded view in FIG. 2 , the charge air cooler 5 comprises a stack of, in the present case, two rows of separate flat tubes 10 , which are arranged sequentially in a depth direction T or a direction of the charge air flow. In the present case, the flat tubes extend in the horizontal plane. The coolant, for example engine coolant of a low-temperature coolant circuit, flows through the two rows R 1 , R 2 of flat tubes in opposite directions. As FIG. 2 shows, the coolant, which enters through the bottom coolant connection 7 , first flows in the row R 2 , which is to the rear in the air flow direction, is then redirected by 180° in a header 11 , and flows through the front row R 1 of flat tubes 10 in the direction opposite the rear row R 2 . With regard to the air flow, flow through the rows R 1 , R 2 takes place first through R 1 and then through R 2 , which is to say in the counterflow method. [0038] Layers of ribs which are not shown are provided in each case between the stacked flat tubes 10 , wherein the ribs are continuous over both rows R 1 , R 2 . Located at each end of the stack of flat tubes 10 are side parts 12 that have multiple corrugation-like ribs 12 a , so that the side parts 12 can be formed from a metal sheet in a simple manner. Together with corresponding rib-shaped formations in the opposite side surfaces of the housing parts 1 a , 1 b , the ribs 12 a form a labyrinth seal; see in particular the detail representation in FIG. 4 . As a result of the multiple overlaps, good sealing of the charge air flow with respect to leakage flows between the charge air cooler 5 and housing parts 1 a , 1 b is achieved with simple means, and a leakage flow along the top and bottom side surfaces is avoided. Depending on requirements, an elastomer seal 13 can also be provided in addition, which in the representation in FIG. 4 is placed on an upward-bent, terminal edge 12 b of the side part 12 as an elongated profile. [0039] The redirecting header 11 that is located on the end, and a header 14 on the inlet side, are made in the same construction style from a formed sheet metal part 16 and four side cover parts 15 . The formed sheet metal part 16 is provided in a center section or base part with two rows of feed-throughs 17 to accommodate the ends of the flat tubes 10 , after which lateral overhangs are folded over to form an outer header wall 18 divided into two parts. The ends of the formed sheet metal part meet in a separating region 19 between the two parts of the header wall 18 . In the case of the redirecting header 11 , openings (not shown) for the coolant to flow through are provided in this separating wall 19 . In the case of the header 14 on the inlet side, the separating wall 19 is made without openings, so that one half of the header 14 is used for the intake of the fluid and the other half of the header 14 is used for the discharge of the fluid. Overall, the charge air cooler is thus designed as a U-flow cooler with regard to the coolant flow. [0040] The headers 11 , 14 are each completed by four cover parts 15 , which are mechanically held in tabs 20 at the edge of the sheet metal part 16 for fixturing. In a variant that is not shown, it is possible to provide only two cover parts per header 11 , 14 . On the inlet-side of header 14 , a profiled fitting 7 is placed in an opening on one of the bottom cover parts 15 , and a fitting 9 that is likewise profiled is placed on a top cover part 15 . The fittings 7 , 9 constitute coolant connections, wherein the bottom fitting 7 is used for the intake of the coolant and the top fitting 9 is used for the discharge of the coolant. [0041] In an alternative embodiment that is not shown, the fittings 7 , 9 can also be put in place after the soldering procedure as separate parts, for example plastic parts, by means of threaded fittings, clips, adhesives or other means. [0042] In a preferred detail design of the exemplary embodiment from FIG. 3 , the charge air cooler 5 is elastically supported on the bottom housing part 1 a by means of a spring member in the form of two spring plates 21 . The spring plates 21 are designed in the form of sheet metal strips with curved ends, wherein the curved ends each rest against one of the cover parts 15 of the headers 11 , 14 . A slight elastic mobility of the charge air cooler 5 relative to the housing 1 is provided by the spring member 21 , so that vibrations of the housing 1 are damped with respect to the charge air cooler 5 , and thermal expansions of the housing 1 and charge air cooler 5 are compensated. In useful fashion for this purpose, sufficient elastic sealing component (not shown) with respect to the feed-throughs 6 , 8 in the housing parts 1 a , 1 b are provided on the coolant connections 7 , 9 . [0043] FIG. 5 and FIG. 6 show two embodiments, in each of which an engine flange 22 for screwing the intake manifold from FIG. 1 to the cylinder head of an internal combustion engine is provided at the bottom housing part 1 a at its outlet-side opening 3 . [0044] In the example from FIG. 5 , the engine flange 22 , as well as the housing part 1 a, is made of plastic, with the engine flange 22 and the housing part 1 a being friction welded to one another. Consequently, they form a one-piece plastic component composed of a uniform material. [0045] In the example from FIG. 6 , the engine flange 22 is made of aluminum, wherein it is screwed by means of threaded fittings 22 a to the housing part 1 a , which is made of plastic like the housing part in FIG. 5 . In a variation that is not shown, it is also possible for both the engine flange 22 and the housing 1 to be made of a light metal such as aluminum. Manufacture from aluminum is desirable in the case of especially high charge pressures or also in the case of high local temperatures, for example in conjunction with a high pressure exhaust gas recirculation system. Insofar as pressures and temperatures allow forming from plastic, this is frequently, but not necessarily, desirable for reasons of cost and weight. Depending on requirements, the housing parts 1 a , 1 b also may be made of different materials, such as aluminum and plastic. [0046] In the most general sense, charge air within the meaning of the invention is understood to mean the gas supplied to the internal combustion engine, and in this sense also includes any desired mixtures of air and exhaust gas if exhaust gas recirculation is provided. The intake manifold in accordance with the invention can be combined with diesel engines as well as with gasoline engines. [0047] In the additional exemplary embodiment shown in FIG. 7 to FIG. 9 , the charge air cooler 5 is supported with respect to the housing 1 by means of elastic support members 23 . The support members, eight in all, are molded as prismatic blocks from an elastic material such as rubber, and they each have bores or recesses 23 a on the top by means of which they are better secured to the housing 1 . [0048] The support members 23 have the cross-section of a right triangle with a curved hypotenuse. They each rest on the side cover pieces 15 of the headers and are fastened in a clamping manner by means of a flexible tab 24 that is provided in a projecting edge of the formed sheet metal part 16 . [0049] Each pair of support members 23 located on opposite side parts 15 of a header constitutes a structural unit together with a coupling link 25 , or is joined together by the coupling link 25 . [0050] The coupling link 25 includes a sealing member formed as an elongated sealing lip that runs along an edge of the header and creates a seal between the housing 1 and the charge air cooler 5 , by which means leakage flows of the charge air are avoided. FIG. 8 shows one of the units composed of support members 23 and coupling link 25 during the process of installation (direction of arrow). The unit [can] be manufactured as a one-piece molded part of a single material, or can also have multiple assembled components. [0051] Another difference from the first exemplary embodiment in FIG. 1 resides in the shape of the headers 11 , 14 . These each have an overhang 26 in the flow direction of the charge air by which they project past an inlet plane formed by the front edges of the flat tubes 10 and an outlet plane formed by the back edges of the flat tubes 10 of the cooler network of flat tubes and ribs. [0052] In the present case, this overhang 26 serves as a support for contact of the coupling link 25 formed as a sealing lip. In alternative embodiments, a separate sealing member can also be arranged on the overhang 26 and/or the overhang forms a labyrinth seal together with a suitable form of the housing that encompasses the overhang. [0053] It is a matter of course that the individual features of the different exemplary embodiments may be appropriately combined with one another as required. [0054] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
An intake manifold is provided that includes an integrated charge air cooler, comprising a housing having a first housing part and a second housing part connected thereto, wherein charge air flows into the housing via an inlet and flows out of the housing via an outlet, wherein the charge air cooler is disposed in the housing and is permeated by the charge air on the path from the inlet to the outlet, wherein the charge air cooler is completely enclosed by the housing, except for passages for passing a cooling fluid, and the charge air cooler is elastically supported relative to the housing, wherein the support takes place by means of at least one elastic bearing element in particular disposed on a collector of the charge air cooler.
5
FIELD OF TECHNOLOGY [0001] The present invention relates to a power tool, and more especially, to a multi-functional power tool capable of realizing impact wrench function and electric drill function or electric screwdriver set function or impact drill function. BACKGROUND OF THE INVENTION [0002] Among the existing power tools, the impact wrench is used to tighten the screw fastener to work piece. It generally comprises a main shaft driven by the rotation of the motor, impact block connected with the main shaft through spiral scroll and ball, and working shaft fit for the impact block through the end tooth and located in front of the impact block. An impact spring is configured in the back of the impact block, which compresses the impact block to enable the impact block to keep reliable coordination with the working shaft. During working, the rotation movement of the main shaft directly outputs to the screw piece through the impact block and working shaft so as to secure the screw piece to work piece. During the tightening, the load on the working shaft gradually increases. When the load exceeds the preset value, the impact moves toward the motor relative to the working shaft through the rolling of the ball in the spiral scroll, and compresses the spring behind it. At the moment that the impact block and the end tooth of the working shaft are unfitted, under the action of the impact spring, the impact block moves forward in axial direction and beats the working shaft in rotation direction, so as to enable the working shaft to keep tightening the screw piece in the direction of rotation. In such cycles, through endless intermittent beating of the impact block, the screw piece can be secured to a work piece in the end. Electric drill is used to drill holes in work piece. However, the user generally requires tightening screw pieces onto the work piece or drilling holes in work piece during working. In this way, it is very inconvenient when the user is required to change tools again and again for operation. [0003] US patent application No. 2005/0199404A1 discloses a power tool capable of realizing impact wrench and electric drill functions in one tool. The power tool secures the impact block ( 7 ) and working shaft ( 8 ) on the outer circumference through function shifting mechanism (the function shifting button 33 and connecting piece 25 shown in FIG. 1 and FIG. 4 of this patent for application) to keep the impact and working shaft relatively fixed, in this way, to realize the shifting between impact wrench function and electric drill function. With this structure, the user is only required to adjust the function shifting button to shift between impact wrench function and electric drill function. European patent application No. EP 1050381 A2 discloses another power tool with both impact wrench function and electric drill function. The power tool secures the impact block ( 5 ) and working shaft ( 6 ) along the axis through function shifting mechanism (Drawing 15 , 16 , 24 , 35 and 36 attached to the patent for application) to keep the impact and working shaft relatively fixed, in this way, to realize the shifting between impact wrench function and electric drill function. However, the power tool disclosed by the abovementioned US patent for application uses a round sleeve with relatively large size as the connecting piece, in this way to increase the overall volume of the power tool, improve manufacturing cost; while the function shifting mechanism of the power tool disclosed by the abovementioned European patent for application requires multiple components' cooperation, and the reliability is reduced due to the complicated structure. SUMMARY OF THE INVENTION [0004] The present invention provides a multi-functional power tool which can realize the shifting between impact wrench function and electric drill function or functions. This function shifting mechanism features simple structure, low manufacturing cost, convenient and efficient operation. [0005] Aimed to realized the above features, the present invention provides: A multi-functional power tool, characterized in that: the power tool comprises an housing, a motor set in the housing, a main shaft driven through the rotation of the motor, a working shaft used to connect corresponding working head when running, wherein an active impact block, which can make axial motion with respect to the main shaft, is configured on the main shaft, a passive impact block which rotates with the working shaft and can alternatively make axial motion with respect to the working shaft is mounted on the working shaft, the active impact block rotates to drive the passive impact block through the coordination of the first end tooth set on the active impact block and the second end tooth set on the passive impact block; the power tool further includes a function shifting button which can move between the first location and the second location to alternatively limit the passive impact block's axial motion with respect to the working shaft, in this way to realize the shifting between the first function and the second function of the power tool. [0006] As an improvement of the invention, the power tool further comprises a compression piece set on the passive impact block and away from the side of the active impact block, wherein the compression piece compresses the passive impact block so that the passive impact block is apt to make movement toward the active impact block. [0007] Aimed to realized the above features, the present invention also could provides: A drilling tool, characterized in that: the power tool comprises an housing, a power source, a main shaft driven by the power source and a working shaft fit for the working head, the main shaft is provided with impact storage block making axial movement with respect to the main shaft, wherein the working shaft is provided with the passive impact block in axial movement, the first working mode and the second working mode exist between the impact storage block and passive impact block, wherein there is no relative axial displacement between the impact storage block and passive impact block in the first working mode, while there is relative axial displacement between the impact storage block and passive impact block in the first working mode, a function shifting button is set on the housing, which includes a location limiting part alternatively limiting the axial movement of the passive impact block. [0008] Aimed to realized the above features, the present invention also could provides: A power tool, comprising: [0009] An housing; [0010] A power source, set in the housing and outputting rotation power; [0011] A working shaft, extending toward the front of the housing and capable of connecting the external working head; [0012] A gear reduction mechanism, set between the power source and working shaft and transmitting the rotation output of power source to the working shaft; [0013] An active impact block, driven by the rotation of output shaft of the gear reduction mechanism; [0014] A passive impact block, capable of engaging with the active impact block and driven by the rotation, the passive impact block is set on the working shaft and rotates to drive the working shaft, and the passive impact block can make axial motion with respect to the working shaft, wherein the active impact block can alternatively ungear the passive impact block when the load on the working shaft increases to the specific value, then mesh with the passive impact block again under the output shaft's rotation driving, thus to exert intermittent impact on the working shaft in the direction of rotation. [0015] An impact shifting piece, capable of alternatively limiting the passive impact block's axial motion with respect to the working shaft, so as to make the impact mechanism shift between the impact status that the active and passive impact blocks can ungear each other and the limiting status that the active and passive impact blocks cannot ungear each other. [0016] Compared with the existing technology, the present invention has the following favorable effects: the power tool is additionally provided with independent passive impact block, and limits the passive impact block's movement together with the active impact block through function shifting button, thus to realize impact wrench function; moreover, this function shifting button can also cancel the limitation to the passive impact block, so as to make it move together with the active impact block, thus to realize drilling function, wherein the abovementioned function shifting mechanism features simple structure, relatively low manufacturing cost, convenient and efficient operation. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The present invention is further detailed in combination with the drawings attached and embodiments hereinafter, wherein: [0018] FIG. 1 is the front view of the multi-functional power tool in the embodiment for the present invention; [0019] FIG. 2 is the exploded view of working parts of the multi-functional power tool shown in FIG. 1 ; [0020] FIG. 3 is partial and sectional scheme of the multi-functional power tool shown in FIG. 1 , mainly disclosing the realizing mechanism of impact wrench function and drilling function, and function shifting mechanism; wherein the power tool is in the low resisting moment status of the impact wrench function status; at this time, the function shifting button is at the first location, and the passive-active impact block is compressed by the sub-passive-active impact block to deviate from function shifting button location; [0021] Similar to FIG. 3 , FIG. 4 shows the power tool in high resistant status of the impact wrench function status; at this time, function shifting button is at the first location, the active-active impact block has deviated from the passive-active impact block under the driving of the motor, while the passive-active impact block is incapable of following the active impact block to make axial movement due to the limitation of function shifting button, thus to realize impact function; [0022] FIG. 5 is similar to FIG. 3 , but the difference lies in that the function shifting button is at the second location, the passive-active impact block can move together with the active-active impact block, this power tool then realizes drilling function accordingly; [0023] FIG. 6 is sectional scheme along A-A line direction in FIG. 4 ; [0024] FIG. 7 is sectional scheme along B-B line direction in FIG. 6 . DESCRIPTION OF PREFERRED EMBODIMENTS [0025] FIG. 1-7 show an embodiment of the multi-functional power tool for the present invention. In this embodiment, the power tool is provided with impact wrench function and drilling function. As shown in FIG. 1 , the power tool 100 comprises an housing 1 distributed horizontally, a handle 6 arranged to form certain angle with the housing and the detachable battery pack 8 at the bottom of the handle. A tool gripper 52 , set in the front of the housing 1 , used to hold different working heads (no drawings) respectively for realizing different functions. If gripping fastener when realizing impact wrench function, hold twist drill while realizing drilling function. A switch 7 is mounted on the handle 6 , through which the operator can start up the power tool through pressing this switch. [0026] FIG. 2 shows the working parts of the power tool configured in the horizontal housing. As shown in FIG. 2 , from right to left of the figure, working parts include a motor 11 and motor output shaft 12 extended from the front of the motor. A gear reduction system is set in front of the motor 11 . In this embodiment, the reduction system is planetary gear reduction system which comprises gearbox 21 and planetary carrier 22 . Internal gear 213 is set in front of the gearbox 21 and several planetary gears 23 are mounted on the planetary carrier 22 . The motor output shaft 12 is in the center of several planetary gears 23 and is engaged with various planetary gears, while the periphery of the planetary gear 23 and internal gear 213 mesh. When the motor runs, the motor output shaft 12 drives the planetary gear 23 to run inside the internal gear 213 , so as to transmit the rotation speed of motor output to the main shaft 24 linking the planetary carrier 22 through certain reduction ratio. A distribution board 13 is set between the motor and gear reduction system, and secured with the main body of the motor 11 through screw stud 14 . A pair of clamping arms 131 extends forwards from the both sides of the distribution board 13 in a symmetrical way, which is firmly clamped on the lug 211 projecting from the back of the gearbox 21 , wherein the inner recess in the outside of the lug 211 forms a notch 212 which can house the lug projecting from the internal wall of the housing 1 (not shown in the drawings). With this structure, the motor 11 and gear reduction system can be reliably secured inside the housing 1 . In front of the gear reduction system sets a mechanism used to realize the impact wrench function, comprising a set of active impact block 31 on the main shaft 24 , impact spring 32 between active impact block 31 and gearbox 21 , and spiral scroll impact mechanism of internal ball located at the junction of active impact block 31 and main shaft 24 , wherein the impact mechanism consists of outer spiral scroll 241 formed by the depression of the surface of main shaft 24 , ball 25 capable of rolling in the outer spiral scroll 241 . In this embodiment, the ball is steel and set in the inner ring of active impact 31 to house the internal spiral scroll 312 of the ball 25 . A pair of the first end teeth 311 protrudes in the front of active impact block 31 in a radial and symmetrical way. Gaskets 33 , 34 are set between impact spring 32 and gearbox 21 , impact spring 32 and active impact block 31 . [0027] By referring to FIG. 3 , the working parts further comprise function adjusting mechanism in front of the active impact block 31 , working shaft 51 extending from the front of the housing 1 , and tool gripper 52 set around the front of the housing 1 . The function adjusting mechanism consists of passive impact block 41 , function shifting button 44 and compression piece 42 , wherein the function adjusting block 41 is set in the face of active impact block 31 , the second end tooth 411 capable of being engaged with the first end tooth 311 of the active impact block 31 extends from the back in a radial and symmetrical way, a shoulder 412 forms in the front and is set between the shoulder 412 and the second end tooth 411 at certain interval. Several key slots 414 are arranged on the circumference of the inner ring of passive impact block 41 , which can correspondingly house several raised keys 511 formed on working shaft 51 . With this structure, the passive impact block 41 can run together with the working shaft 51 , and the passive impact block 41 can make axial movement with respect to the working shaft 51 . It is easy to figure out the solution for common technicians in this field that key slot and raised key can be interchanged, namely, key slot can be set on the working shaft and raised key can be set on passive impact block. In this embodiment, the compression piece 42 is a spiral spring, wherein the back props up the passive impact block through a gasket 43 , and the front props up the inner wall of the housing 1 . Certainly, the compression piece can be also composed of plate spring or other elastic elements. In front of the working shaft 51 sets housing slot 512 capable of housing corresponding working heads when realizing different functions and being clamped and secured firmly through the tool gripper 52 . [0028] By referring to FIG. 6 and FIG. 7 , in this embodiment, the function shifting button 44 comprises the operating part 441 outside the housing 1 and the location limiting part 442 capable of extending into the housing 1 , wherein the operating part 441 is a sliding block and capable of sliding on the outer circumference of the housing 1 . A slide way 443 is arranged on the operating part 441 along the vertical direction. The operating part 441 and location limiting part 442 are connected through a movable pivot 444 which (the movable pivot 444 ) can roll in the slide way 443 of the operating part 441 . The upper part of the location limiting part 442 is connected with the movable pivot 444 to allow the pivot to rotate around the movable pivot. The location limiting part 442 can extend into the housing through the opening in the wall of the housing 1 , and can be alternatively located in the spacing area 413 between the shoulder 412 of the passive impact block 41 and the second end tooth 411 , and can be against the shoulder 412 at a specific location. The fixed pivot 445 is set in the opening area of the housing 1 . The middle part of the location limiting part 442 is connected with the fixed pivot 445 to allow the pivot to rotate around the pivot. With this structure, the user is only required to glide the operating part 441 on the surface of the housing 1 , in this way, the location limiting part 442 can alternatively enter into the spacing area 413 between the shoulder 412 of the passive impact block 41 and the second end tooth 411 , or stay outside the spacing area 413 , such as in the opening area of the housing. Certainly, it is easy to figure out the solution for common technicians in this field that the function shifting button is made into simple plug-in type element, namely, located in the spacing area after plugging through the housing opening, or outside the spacing area after unplugging. [0029] FIG. 3 and FIG. 4 disclose the working situation when the power tool realizes impact wrench function, wherein FIG. 3 shows the low resisting moment status when the tool is in the impact wrench function status, FIG. 4 shows the high resisting moment status when the tool is in the impact wrench function status. When realizing the impact wrench function, the function shifting button 44 is adjusted to the first location as shown in FIG. 6 , at this time, the function shifting button 44 and the passive impact block fit each other, namely, the location limiting part 442 is located in the spacing area 413 of the passive impact block. The passive impact block 41 is apt to make movement toward the active impact block 31 under the compression of the compression piece 42 . However, the pressure from the impact spring 32 makes the first end tooth 311 of the active impact block 31 and the second end tooth 411 of the passive impact block mesh with each other, so as to limit and stop the movement of the passive impact block 41 . When the power tool runs, the main shaft 24 is driven by the rotation of the motor output shaft 12 . Through the driving of the ball 25 included in inner and outer spiral scrolls 312 , 241 , the active impact block 31 follows to rotate, then the passive impact block 41 rotates as well, and then tightens the nuts (no shown in the drawings) rapidly through the working shaft 51 and tool gripper 52 to drive the working head (now shown in the drawings). [0030] When the nut end face contacts the surface of the working piece (not shown in the drawings), the resisting moment rapidly increases. After reaching a certain value, the active impact block 31 and passive impact block 41 engaged with each other are both held back. The passive impact block 41 stops rotation, but the main shaft 24 keeps rotation under the driving of the motor output shaft 12 , in this way, to force the ball 25 to roll along the scroll by overcoming the friction force between the inner and outer spiral scrolls 312 , 241 , so as to push the active impact block 31 to move toward the motor and compress the impact spring 32 . In this process, the early-stage passive impact block 41 makes axial movement at a tiny distance along with the active impact block 31 under the action of the compression piece 42 . However, when the location limiting part 442 of the function shifting button 44 is propped up, further movement is impossible. Therefore, the active impact block 31 is gradually away from the passive impact block 41 in the axial direction. When the axial movement distance of the active impact block 31 exceeds the height of the second end tooth 411 of the passive impact block, namely, at the moment the active impact block 31 and passive impact block 41 ungear each other, the main shaft 24 drives the active impact block 31 to rotate so that the first end tooth 311 slides over the second end tooth 411 of the passive impact block. At the moment of sliding, due to the impact spring 32 , the ball 25 returns to the original location along the spiral scrolls 312 , 241 again. The active impact block 31 is pushed forwards, and impacts the second end tooth 411 of the passive impact block due to the accelerated rotation of the main shaft 24 so that the passive impact block 41 keeps movement in the rotation direction. In such cycles, the screw piece can be secured under the force of impact. It is easy to figure out the solution for common technicians in this field and the outer ball spiral scroll impact structure can be also adopted to realize the function of impact wrench. The working process and principles are the same to the inner ball spiral scroll impact structure disclosed in this embodiment, so they are not detailed herein. [0031] When realizing the abovementioned impact wrench function, it is required that the active impact block 31 rotates intermittently to impact the passive impact block 41 so as to enable the working head (fastener) capable of tightening the nuts. However, when realizing the drilling function, it is only required that the working head (twist drill) keeps drilling, while the intermittent impact of the active impact block is not required any more. By referring to FIGS. 5 and 7 , when the function shifting button 44 is adjusted to the second location as shown in FIG. 7 , namely, the location limiting part 442 is located outside the spacing area 413 of the passive impact block 41 . At this time, the power tool is in the working status of drilling function. During drilling, since the resisting moment of the working shaft 51 gradually increases, the active impact block 31 moves toward the motor. At this time, due to the lack of the limitation of the function shifting button 44 , the passive impact block 41 makes axial movement along with the active impact block 31 under the compression of the compression piece 42 with respect to the working shaft 51 . Meanwhile, active impact block 31 , passive impact block 41 and working shaft 51 moves together in the rotation direction. Since the passive impact block 41 and active impact block 31 cannot ungear each other, namely the two blocks cannot form an impact, continuous drilling of the working head can be ensured. [0032] In other embodiments, when the function shifting button is at the second location, namely the passive impact block moves together with the active impact block, the clutch structure added between the planetary gear reduction system of the power tool and inner ball spiral scroll impact structure can realize the electric screwdriver set function correspondingly, while the active impact block structure of dynamic, static end teeth in the front of the working shaft can realize impact drill function correspondingly. The abovementioned functions can be set separately and form double-functional power tool in combination with the impact wrench function, form tri-functional power tool or quarter-functional power tool by means of overlying setting. Since the abovementioned functional mechanism added is the existing technology and it has been described in detail in the reference document cited by the background technology of this application, it is unnecessary for the applicant to give details herein.
The invention related to a multi-functional power tool, comprises an housing, a motor set in the housing, a main shaft driven through the rotation of the motor, a working shaft extended outside the housing, an active impact block, which can rotate with and make axial motion with respect to the main shaft, is configured on the main shaft, a passive impact block which rotates with the working shaft and can alternatively make axial motion with respect to the working shaft is mounted on the working shaft, the active impact block rotates to drive the passive impact block through the coordination of the first end tooth set on the active impact block and the second end tooth set on the passive impact block; the power tool further includes a function shifting button which can move between the first location and the second location to alternatively limit the passive impact block's axial motion with respect to the working shaft, in this way to realize the shifting between the first function and the second function of the power tool. This function shifting mechanism features simple structure, low manufacturing cost, convenient and efficient operation.
1
FIELD OF THE INVENTION This invention relates to safety arrangements for electric devices having cutting, shredding or the like members, particularly electric garden shredders. BACKGROUND OF THE INVENTION Electric shredders and similar electrical appliances for shredding, cutting or disintegrating material fed to rotating operating members are known. For example, U.S. Pat. No. 4,360,166 discloses an electric garden shredder having a removable feed chute through which garden trash is fed to a shredding rotor. For cleaning or other purposes the feed chute or other container may be removable so exposing the cutting or shredding members. As a safety precaution it is desirable to interrupt power to the electric motor driving the cutting member when the feed chute is removed. United Kingdom Pat. No. 2,098,504 B discloses an electric garden shredder in which removal of the feed chute automatically opens a switch to disconnect power to the electric motor. However, with the feed chute removed, power can be restored to the motor by manually depressing this safety switch. Also, U.S. Pat. No. 2,899,140 discloses an ice crusher in which removal of the crushed ice container triggers a safety switch to disconnect the electric motor. However, again, after the container is removed and the hammer crushing rotor is somewhat exposed, the safety switch is capable of manual actuation to energize the motor and operate the crushing rotor. SUMMARY OF THE INVENTION It is the object of the present invention to provide a safety arrangement for electric shredders and the like whereby the cord by which electrical power is supplied to the device must be disconnected from the electric motor before a feed chute or other container is removed to expose an operating member. A feature by which this is achieved in a preferred embodiment of the invention is by attaching the supply cord to the devices by means of a "lost-motion" mechanical connection, and arranging a connector of the supply cord to prevent removal of the feed chute or other container while the supply cord is electrically plugged to the device. In a further preferred feature, the connector of the supply cord is mechanically coupled to the removable feed chute or other container so that the supply cord is totally removed therewith. This has the advantage that once the removable container is removed to expose the operating member, the motor cannot be energized. A further preferred feature provides a supply cord with incompatibly configured or dimensioned connectors at both ends so that a normal extension cord cannot be plugged directly to the device. This has the advantage that the motor can then only be readily energized via the supply cord attached to the removable container, this only being possible when the removable container is in position concealing the cutting or other operating member. Accordingly, therefore, there is provided by the present invention an electric device having an electric motor drivingly connected to an operating member, for example a rotatable cutting or shredding assembly. A removable container, for example a feed chute, is associated with the operating member, to normally shield the latter, but the operating member is exposed when the container is removed. Motor socket means provides for connection of electrical power to the motor, and is preferably mounted on the motor. Cable socket means, preferably connected to one end of a cord set, plugs to the motor socket means for supplying electrical power thereto. Coupling means, for example a lost-motion linkage, may mechanically couple the cable socket means to the device, preferably to the removable container thereof, and allow relative motion between the two socket means when the container is in position shielding the operating member. Stop means prevents removal of the container from the device when the two socket means are plugged together, and allows such removal when the two socket means are relatively moved apart to unplug them. The cable socket means may be movably mounted on a bracket attached to the removable container, and may engage under a base frame portion of the device when plugged to the motor socket means but clear this base frame portion when unplugged. Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIG. 1 is a side elevational view diagrammatically illustrating an electric garden shredder to which the present invention has been applied; FIG. 2 is a simplified diagrammatic vertical section of part of the electric shredder of FIG. 1 and illustrates the shredding mechanism; FIG. 3 is a perspective view of a cord set according to the present invention and shown removed from the electric shredder of FIG. 1; FIG. 4 is a fragmentary perspective view showing a bracket according to the invention for attaching the cord set of FIG. 3 to the upper part of the electric shredder in FIG. 1; FIG. 5 is an elevational view looking into the upper end connector of the cord set of FIG. 3 and showing the bracket of FIG. 4 engaged therein; FIG. 6 is a front view of a portion of the electric shredder according to the invention in the direction of the arrow 6 in FIG. 1 with the upper connector of the cord set and the bracket of FIG. 4 shown in section, and with the upper end of the cord set in a position in which it is electrically disconnected from the electric motor of the electric shredder; FIG. 7 is a diagrammatic fragmentary view of part of FIG. 6, with parts omitted for clarity and the upper connector of the cord set not shown in section, and with the upper end of the cord set plugged to the electric motor and in electrical connection therewith; and FIG. 8 is a diagrammatic view in the direction of FIG. 1 illustrating a male electrical connection socket on the electric motor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show an electric garden shredder to which the safety arrangement of the present invention has been applied, the preferred embodiment of this safety arrangement being shown in greater detail in FIGS. 3 through 8. FIG. 1 shows the electric garden shredder 10 having an upper vertical cylindrical feed chute 12 mounted on and attached to a three legged base 14. An electric motor 16 for driving the mechanism of the shredder is mounted under the upper part of the base 14. A cord set 18 for connecting the motor 16 to a source of electrical supply has a lower end connector 20, for connection to an outside extension cable, and an upper end connector 22 attached to the shredder 10. The feed chute 12 has an upper main inlet 24 and a smaller auxiliary inlet 26 to one side. A thumb screw 28 tightly secures a flanged base 29 of the feed chute 12 to the base 14. In use, garden trash is fed into the feed chute 12 through either of the inlets 24, 26 and the shredded trash 30 is discharged into a container 32. FIG. 2 illustrates the shredding mechanism of the shredder 10, and shows a rotor 34 having upwardly inclined cutting blades 36 and surface cutting blades 38, the rotor 34 being mounted on a short shaft 40 journaled in a bearing 42. A pulley 44 on the lower end of the shaft 40 is driven by a pulley 46 of the motor 16 via an endless belt 48. The motor 16 is mounted for adjustable movement sideways relative to the base 14 for adjusting the tension of the belt 48. For further details of this cutting and shredding mechanism and the operation thereof to shred garden trash, reference is made to U.S. Pat. No. 4,360,166 the disclosure of which is hereby incorporated herein by reference. FIG. 3 shows in greater detail the cord set 18. The upper end connector 22 is formed with a large shroud-like housing 50 of electrically insulating plastic material. In side view, the housing 50 has a narrower top portion and a wider lower portion with a step 52 on each side therebetween. Each side step 52 is formed with an inwardly projecting lip 54 of box-like cross section which extends from the front to the back of the housing 50. Below each lip 54 is a partition structure 56 which defines a channel 58 below the respective lip 54 with a gap 60 between the top of the partition structure 56 and the underside of the respective lip 54. The lower portion of the housing 50 has two concentric cylindrical partitions 62, 64 formed integrally therewith, the larger cylindrical partition 62 being connected to lower wall portions of the partition structures 56. The smaller inner cylindrical partition 64 is recessed below the outer edge of the cylindrical partition 62 and contains a female electrical socket 66. The female socket 66 is secured by a screw 70 and has two bores 68 for receiving electrical plug prongs. The upper portion of the housing 50 has a series of radially extending reinforcing webs 72 recessed below the front edge thereof, i.e. the right hand edge in FIG. 3. Transverse webs 74 extend between the lips 54 and the partition structures 56, and support sockets for securing a retaining metal plate between the partition structures 56 as will be described in greater detail later. The lower end connector 20 has a cylindrical wall socket 76 containing two rectangular cross sectioned plug prongs 78. It should be particularly noted that the plug prongs 78, apart from being of different cross sectional shape to the bores 68 of the female socket 66, will not plug into the bores 68 as the bores 68 are smaller. The size and configuration of the plug prongs 78 are determined by the type of electrical supply available and to be used with the shredder; whatever the shape and size of the prongs 78 are, the shape and size of the bores 68 are chosen to be incompatible so that the available electrical supply could not be connected to the female socket 66, as will be more fully understood later. FIG. 4 is a perspective view of a metal bracket 80 attached to a side flange of the base 29 of the feed chute 12. In FIG. 1 the bracket 80 is concealed by the upper end connector 22 inside which it is also attached. The upper end of the bracket 80 has a transverse slot 82 through which two screws 84 extend and secure the bracket to the flange of the base 29. Washers 86 are disposed between the heads of the screws 84 and the bracket 80, the slot 81 enabling the bracket to be moved a limited amount relative to the flanged base 29 for alignment purposes. In end view the bracket 80 is L-shaped and has a base leg or step 88 which extends outwardly away from the flanged base 29. On either side of the leg 88 is a downwardly turned side flange 90. At the outer extremity of the leg 88, between the side flanges 90, is a shorter downwardly turned front flange 92 which functions as a stop, as will be described later. FIG. 5 shows a view looking into the upper connector 22, i.e. from the right hand side in FIG. 3, with the L-shaped bracket 80 assembled therein. For clarity, the bracket 80 is not shown connected to the flanged base 29. The bracket 80 fits inside the side walls of the housing 50 and between the inwardly turned lips 54 with the downward side flanges 90 slidably engaging in the channels 58. After the bracket and the upper connector 22 have been so assembled, a metal retaining plate 94 is secured by two screws 96 to the housing 50 to cover the transverse flange 92 of the bracket 80 and so retain the bracket in the housing 50. The side flanges 90 are capable of limited sliding movement backwards and forwards in the channels 58 with the transverse flange 92 engaging the retaining plate 94 to limit movement of the plate 80 out of the housing 50. FIG. 5 also shows a front view of the female socket 66 with the electrical connection bores 68, and a member 98 physically anchoring the cord of the cord set 18 inside the cylindrical partition 62. FIG. 6 is a view in the direction of the arrow 6 in FIG. 1 and shows the bracket 80 and upper cord set connector 22, both in section, inter-connected and the bracket 80 connected by screws 84 to the flanged base 29 of the feed chute 12. A cylindrical connection socket 102 extends from the side of the electric motor 16 and contains two cylindrical plug prongs 104. The plug prongs 104 align with the bores 68 of the female socket 66, but are shown in FIG. 6 disengaged therefrom with the upper cord set connector 22 moved in the direction of the arrow D to its maximum distance away from the shredder's base 14 and the socket 102. In this position the feed cylinder 12 can be removed from the base 14 by unscrewing the thumb screw 28 and then lifting upwardly, the cord set connector 22 being able to move upwardly therewith clearing the motor socket 102 and the side of the base 14. In the position shown in FIG. 6, the connector 22 is prevented from moving to the left further and being disconnected from the bracket 80 by the retaining plate 94 of the connector 22 engaging the flange 92 of the bracket 80. One of the screws 96 securing the retaining plate 94 in position can be seen threadedly engaged in a socket 100 extending from the back wall of the connector 22. The connector 22 can be moved towards the base 14 and motor socket 102 with the bracket side flanges 90 sliding in the channels 58 (see also FIGS. 3, 4 and 5) and the transverse flange 92, together with the lower leg 88 of the bracket 80, sliding inwardly into and along a cavity 110 inside the connector 22. Such movement is not hindered by the base 14 due to the narrower top portion of the connector 22, and the step 52 at the bottom thereof being at a slightly lower lever than the bottom outside edge 106 of the base 14, i.e. the step 52 can pass under the lower edge 106 of the base 14. During such inward movement of the connector 22, the cylindrical partition 62 passes over the outside of the cylindrical motor socket 102, and the female socket 66 enters inside the motor socket 102 so that the plug prongs 104 enter into the bores 68 and make electrical connection between the cord set 18 and the motor 16. As can be seen, the inner surface of the cylindrical partition 62 and the outer surface of the motor socket 102 are both slightly tapered to ensure a tight fit therebetween as the cylindrical partition 62 is pressed over and onto the motor socket 102. FIG. 7 illustrates the cord set connector 22 in electrical connection with the motor socket 102 after the connector 22 has been moved in the direction of the arrow C fully towards the flanged base 29 and the motor socket 102. The step 52 between the upper and lower portions of the connector 22 has passed below the lower edge 106 of the base frame 14, and in broken lines the motor socket plug prongs 104 can be seen engaged in the female socket 66 of the connector. In this position electrical connection between the cord set 18 and the motor 16 is established, and the feed cylinder 12 cannot be lifted off the base frame 14 even if the thumb screw 28 (see FIGS. 1 and 6) is unscrewed. This is firstly because of the engagement of the plug prongs 104 in the female socket 66, secondly because of the engagement of the outer cylindrical partition of the connector 22 over the motor socket 102, and thirdly because of the engagement of the step 52 of the connector 22 underneath the lower edge 106 of the base frame 14. Thus, the cutting rotor 34 cannot be exposed while there is electrical connection between the cord set 18 and the motor 16. FIG. 8 is a fragmentary view in the direction of the arrow C in FIG. 7 but with the cord set connector 22 and the bracket 80 omitted to clearly show the motor socket 102. Spaced concentrically inwardly of the peripheral wall of the motor socket 102, and recessed well below the outwardly extending end thereof, is secured a plug base 112 carrying the two outwardly extending plug prongs 104. These motor plug prongs 104 are differently configured and shaped to the plug prongs 78 of the lower end connector 20 of the cord set, so that the female end of any electrical extension cord to which the lower end cord set connector 20 could be plugged, will not plug to the motor plug prongs 104. This provides the safeguard that when the feed chute 12 together with the cord set connector 22 have been removed from the shredder, the available electrical extension cord cannot be plugged directly into the motor socket 102; this further prevents energisation of the motor 16 when the cutting blades 36, 38 are exposed. It will be appreciated, therefore, that by attaching the cord set connector 22 to the feed chute 12 with a type of lost-motion connection therebetween, both physical and electrical connection between the cord set connector 22 and the motor 16 have to be broken before the feed chute 12 can be removed to expose the cutting blades. Further, electrical connection between the cord set connector 22 and the motor 16 cannot be re-established until the feed chute 12 is correctly positioned. It should be further noted that even should feed chute retaining screw 28 become loosened, the feed chute would still be retained in position on the base frame 14 by the cord set connector 22 and the bracket 18 as long as there was electrical connection between the cord set connector 22 and the motor 16. Although the preferred embodiment of the present invention has been described above in relation to a garden shredder, it will be appreciated that it could be applied to other electrical devices having a feed chute or container covering one or more movable cutting blades. For example, the present invention could be employed with a food processor and other kitchen appliances having rotating cutting, shredding or beating members. The above described embodiments, of course, are not to be construed as limiting the breadth of the present invention. Modifications, and other alternative constructions, will be apparent which are within the spirit and scope of the invention as defined in the appended claims.
An electric device, for example a shredder, comprises a cutter mounted on a base and driven by an electric motor, the cutter being concealed by a removable feed chute. A plug connector of a cord set is movably secured to the feed chute, and is moved towards and away from the feed chute to plug it with and unplug it from a plug connector of the motor. The plugging together of the plug connectors prevents removal of the feed chute; it being necessary to unplug the connectors to disconnect electrical supply to the motor by moving the cord set plug connector outwardly of the base before the feed chute can be removed to expose the cutter. Preferably, the cord set has incompatible plug connectors at each end to prevent a normal extension cord being plugged to said motor plug connector when said feed chute is removed.
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CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 13/614,988, filed Sep. 13, 2012, and entitled “SECURELY FILTERING TRUST SERVICES RECORDS.” The entire content of the foregoing application is incorporated by reference herein in its entirety. BACKGROUND Computers have become highly integrated in the workforce, in the home, in mobile devices, and many other places. Computers can process massive amounts of information quickly and efficiently. Software applications designed to run on computer systems allow users to perform a wide variety of functions including business applications, schoolwork, entertainment and more. Software applications are often designed to perform specific tasks, such as word processor applications for drafting documents, or email programs for sending, receiving and organizing email. In many cases, software applications are designed to interact with other software applications or other computer systems. For example, web browsers allow users to access information such as web pages, email, videos, music and other types of data. In some cases, enterprises or other organizations may provide data on these web servers that is intended only for certain users (e.g. employees). In such cases, the employees typically log in and are authenticated before being given access to the data. In other scenarios, enterprises or other organizations may provide some or all of their data via a third party data host such as a cloud hosting company. Such cloud hosting companies may provide the organization's data and/or applications to a wide variety of authenticated and unauthenticated users. BRIEF SUMMARY Embodiments described herein are directed to securely filtering trust services records. An embodiment includes receiving a trust services record that includes a plurality of security components that are selected from the group comprising: a trust services certificate, a principal certificate, a group certificate, and a trust services policy. The trust services record is usable to secure data that is stored in an untrusted location. The embodiment also includes determining whether the trust services record has been tampered with. The determination includes verifying each of the plurality of security components of the trust services record. The trust services record is determined to have not been tampered with when verification of each of the plurality of security components passes, and is determined to have been tampered with when verification of any of plurality of security components fails. The embodiment also includes filtering the trust services record based on the determination of whether the trust services record has been tampered with. The filtering includes, when the trust services record is determined to have not been tampered with, allowing performance of at least one task with respect to the secured data; and, when the trust services record is determined to have been tampered with, disallowing performance of any task with respect to the secured data. This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Additional features and advantages will be set forth in the description which follows, and in part will be apparent to one of ordinary skill in the art from the description, or may be learned by the practice of the teachings herein. Features and advantages of embodiments described herein may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Features of the embodiments described herein will become more fully apparent from the following description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS To further clarify the above and other features of the embodiments described herein, a more particular description will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only examples of the embodiments described herein and are therefore not to be considered limiting of its scope. The embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 illustrates a computer architecture in which embodiments described herein may operate including securely filtering trust services records. FIG. 2 illustrates a flowchart of an example method for securely filtering trust services records. FIG. 3 illustrates a flowchart of an alternative example method for securely filtering trust services records. FIG. 4 illustrates an embodiment in which bad trust services records are filtered out. DETAILED DESCRIPTION Embodiments described herein are directed to securely filtering trust services records. In one embodiment, a client computer system receives at least one of the following trust services records: a trust services certificate, a principal certificate, a group certificate and a trust services policy. The client computer system performs a time validity check to validate the trust services record's timestamp, performs an integrity check to validate the integrity of the trust services record and performs a signature validity check to ensure that the entity claiming to have created the trust services record is the actual creator of the trust services record. In another embodiment similar to that described above, a client computer system receives at least one of the following trust services records: a trust services certificate, a principal certificate, a group certificate and a trust services policy. The client computer system performs a time validity check to validate the trust services record's timestamp, performs an integrity check to validate the integrity of the trust services record and performs a signature validity check to ensure that the entity claiming to have created the trust services record is the actual creator of the trust services record. The client computer system then, based on the time validity check, the integrity check and the signature validity check, determines that the trust services record is valid and allows a client computer system user to perform a specified task using the validated trust services record. The following discussion now refers to a number of methods and method acts that may be performed. It should be noted, that although the method acts may be discussed in a certain order or illustrated in a flow chart as occurring in a particular order, no particular ordering is necessarily required unless specifically stated, or required because an act is dependent on another act being completed prior to the act being performed. Embodiments described herein may comprise or utilize a special purpose or general-purpose computer including computer hardware, such as, for example, one or more processors and system memory, as discussed in greater detail below. Embodiments described herein also include physical and other computer-readable media for carrying or storing computer-executable instructions and/or data structures. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer system. Computer-readable media that store computer-executable instructions in the form of data are computer storage media. Computer-readable media that carry computer-executable instructions are transmission media. Thus, by way of example, and not limitation, embodiments described herein can comprise at least two distinctly different kinds of computer-readable media: computer storage media and transmission media. Computer storage media includes RAM, ROM, EEPROM, CD-ROM, solid state drives (SSDs) that are based on RAM, Flash memory, phase-change memory (PCM), or other types of memory, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store desired program code means in the form of computer-executable instructions, data or data structures and which can be accessed by a general purpose or special purpose computer. A “network” is defined as one or more data links and/or data switches that enable the transport of electronic data between computer systems and/or modules and/or other electronic devices. When information is transferred or provided over a network (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a transmission medium. Transmission media can include a network which can be used to carry data or desired program code means in the form of computer-executable instructions or in the form of data structures and which can be accessed by a general purpose or special purpose computer. Combinations of the above should also be included within the scope of computer-readable media. Further, upon reaching various computer system components, program code means in the form of computer-executable instructions or data structures can be transferred automatically from transmission media to computer storage media (or vice versa). For example, computer-executable instructions or data structures received over a network or data link can be buffered in RAM within a network interface module (e.g., a network interface card or “NIC”), and then eventually transferred to computer system RAM and/or to less volatile computer storage media at a computer system. Thus, it should be understood that computer storage media can be included in computer system components that also (or even primarily) utilize transmission media. Computer-executable (or computer-interpretable) instructions comprise, for example, instructions which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, or even source code. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the described features or acts described above. Rather, the described features and acts are disclosed as example forms of implementing the claims. Those skilled in the art will appreciate that various embodiments may be practiced in network computing environments with many types of computer system configurations, including personal computers, desktop computers, laptop computers, message processors, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile telephones, PDAs, tablets, pagers, routers, switches, and the like. Embodiments described herein may also be practiced in distributed system environments where local and remote computer systems that are linked (either by hardwired data links, wireless data links, or by a combination of hardwired and wireless data links) through a network, each perform tasks (e.g. cloud computing, cloud services and the like). In a distributed system environment, program modules may be located in both local and remote memory storage devices. In this description and the following claims, “cloud computing” is defined as a model for enabling on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services). The definition of “cloud computing” is not limited to any of the other numerous advantages that can be obtained from such a model when properly deployed. For instance, cloud computing is currently employed in the marketplace so as to offer ubiquitous and convenient on-demand access to the shared pool of configurable computing resources. Furthermore, the shared pool of configurable computing resources can be rapidly provisioned via virtualization and released with low management effort or service provider interaction, and then scaled accordingly. A cloud computing model can be composed of various characteristics such as on-demand self-service, broad network access, resource pooling, rapid elasticity, measured service, and so forth. A cloud computing model may also come in the form of various service models such as, for example, Software as a Service (“SaaS”), Platform as a Service (“PaaS”), and Infrastructure as a Service (“IaaS”). The cloud computing model may also be deployed using different deployment models such as private cloud, community cloud, public cloud, hybrid cloud, and so forth. In this description and in the claims, a “cloud computing environment” is an environment in which cloud computing is employed. Additionally or alternatively, the functionally described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Program-specific Integrated Circuits (ASICs), Program-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), and other types of programmable hardware. Still further, system architectures described herein can include a plurality of independent components that each contribute to the functionality of the system as a whole. This modularity allows for increased flexibility when approaching issues of platform scalability and, to this end, provides a variety of advantages. System complexity and growth can be managed more easily through the use of smaller-scale parts with limited functional scope. Platform fault tolerance is enhanced through the use of these loosely coupled modules. Individual components can be grown incrementally as business needs dictate. Modular development also translates to decreased time to market for new functionality. New functionality can be added or subtracted without impacting the core system. FIG. 1 illustrates a computer architecture 100 in which at least one embodiment may be employed. Computer architecture 100 includes server computer system 101 and client computer system 115 . Either or both of server and client computer systems 101 and 115 may be any type of local or distributed computer system, including a cloud computing system. The computer systems include various modules for performing a variety of different functions. For instance, server computer system 101 includes trust service 102 and portal 103 . An administrator or other computer user may use portal 103 to control and manage the trust services A and B. The trust services allow encryption keys, certificates and data policies to be stored in a public or untrusted data store (perhaps trust services storage 130 , which may be trusted or untrusted) in encrypted form, while ensuring that only authorized users can access the data. The trust services may use trust services records 104 in their communication with the client computer system 115 and/or with of other computer systems. These trust services records 104 may include multiple different elements including a trust services certificate 105 , a principal certificate 106 , a group certificate 107 and a trust services policy 108 . Each of these elements may have its own timestamp 109 and/or digital signature 110 . These elements will be explained further below. The client computer system 115 may include various different elements including modules 116 - 120 . Each of these modules may represent a separate software function, or the functions may be combined into a trust services software development kit (SDK). The software modules include receiving module 116 . The receiving module may receive the trust services records 104 from trust service 102 . The receiving module 116 may also receive data and/or metadata from trust service 102 and/or trust services storage 130 . The receiving module may pass the received trust services records to various modules including the time validity check module 117 , the integrity check module 118 and/or the signature validity check module. If a record has passed each of these checks (or, in some cases, at least a certain number of them), the record validation module 120 will indicate that the record is valid and send the record 121 (as validated by module 120 ) to the client 125 and/or store the record internally. This validated record may then be used by the client 125 to perform a specified task 126 . In some cases, client 125 may be a business owner, or an IT operator for a business. Businesses and other organizational entities may be constrained by privacy and security concerns. In such cases, trust services (e.g. 102 ) may be used to allow the business to use (potentially untrusted) cloud data storage and use other cloud platform services. The trust services provide data-centric security that allows data to reside in a public cloud, while ensuring that only authorized users can access the data. The modules of the client computer system 115 allow trust services records 104 to be securely filtered to ensure that the records are valid, have not been injected by the server computer system, by another computer system or by a third party, have not been tampered with, etc. This filtering system also prevents the server computer system 101 from tricking the client into migrating data that should be encrypted, in the clear, to the cloud. Embodiments described herein provide the ability to perform trusted filtering of trust services records on the client computer system 115 . The embodiments also describe the various checks that are performed to ensure proper filtering. A trust service (e.g. 102 ) application programming interface (API) may be used to provide the checks including a time validity check 117 , an integrity check 118 and a signature validity check 119 . Each of these operations is cryptographically provable and uniquely traceable to the person who performed it. Moreover, operations performed by entities residing in or external to the cloud cannot compromise the privacy of the client's data and encryption keys. Each record in used by the trust services is digitally signed and, as such, can be traced to the creator. When the receiving module 116 on the client computer system 115 downloads records from the trust services, the client computer system makes sure that only records signed by locally trusted certificates are decrypted and used during encryption or decryption operations. Then, if a new record is injected into the trust services by the server 101 or by a third party, the client computer system will filter the new record out based on the signature validity check 119 and trusted principals. If the server or a third party manages to somehow delete a trust services record, a client application (e.g. a software development kit (SDK)) on the client computer system will find no trusted record and raise an error, ensuring that no clear text data will be leaked. Trusted filtering of records on the client computer system 115 protects clients (e.g. 125 ) from malicious servers and untrusted entities. Trusted filtering also ensures that the client does not get tricked into compromising sensitive data in the cloud (e.g. by sending sensitive data in the clear to the cloud). Any record that has been tampered with, deleted or injected into the trust services by the server or an untrusted party is filtered out and can thus be prevented from causing harm to the client computer system 115 . Trust services 102 stores non-user data in three federations: Key Federation, Policy Federation and Certificate Federation. These federations store the keys, certificates and policies that govern who is authorized to access what data and how user data is pushed to the cloud. Before clients can pull user data from the cloud and access it, they first interact with data stored in trust services (e.g. records in trust services that are relevant to the client) to check if they are authorized to access the data, and if yes, then how they can decrypt the data. Clients cannot blindly trust information in the records obtained from trust services as this information can be corrupted/misrepresented by the server or a third party. In order to introduce client trust in these records, a set of rules or policies may be established while reading data from trust services storage 130 . The various checks ( 117 - 119 ) made by the client using a combination of these rules ensure that the client does not get tricked into accessing manipulated data. At least in some embodiments, elements of the trust services records 104 , including certificate records 105 , principal certificate records 106 , group certificate records 107 and policy records 108 , each include a time validity check. When a client computer system downloads these records from a trust service (e.g. 102 ) the client computer system verifies that, for example, the expiration date on the record is not passed and that the “valid from” and “timestamp” fields on the record are in the past. One of the checks made on multiple different record types including record certificates, principal and group certificate records and policy records, is the integrity check 118 . This check works by constructing a new record globally unique identifier (GUID) based on the content and metadata of the record and then comparing it with the GUID on the record obtained from the trust service. This ensures that if a record was manipulated in the cloud, its GUID would not match the one constructed from the manipulated content. This prevents the user from decrypting records that may have been tampered with. Another check performed is the signature validity check 119 . This check is performed on each of the four kinds of records mentioned above (i.e. 105 - 108 ). The client computer system 115 performs this check to ensure that the entity claiming to be the creator of the record is the actual creator. The client computer system also ensures that the record was created by one of its trusted entities. If one or more of the checks fails, the record will be filtered out and discarded. Each of these concepts will be explained further below with regard to methods 200 and 300 of FIGS. 2 and 3 , respectively. In view of the systems and architectures described above, methodologies that may be implemented in accordance with the disclosed subject matter will be better appreciated with reference to the flow charts of FIGS. 2 and 3 . For purposes of simplicity of explanation, the methodologies are shown and described as a series of blocks. However, it should be understood and appreciated that the claimed subject matter is not limited by the order of the blocks, as some blocks may occur in different orders and/or concurrently with other blocks from what is depicted and described herein. Moreover, not all illustrated blocks may be required to implement the methodologies described hereinafter. FIG. 2 illustrates a flowchart of a method 200 for securely filtering trust services records. The method 200 will now be described with frequent reference to the components and data of environment 100 . Method 200 includes an act of the client computer system receiving at least one of the following trust services records: a trust services certificate, a principal certificate, a group certificate and a trust services policy (act 210 ). For example, receiving module 116 of client computer system 115 may receive trust services record 104 which includes trust services certificate 105 , principal certificate 106 , group certificate 107 and/or trust services policy 108 . Other trust services records not mentioned may also be included within record 104 . Any of the trust services records may be digitally signed by the record's creator. Thus, if an administrator signs trust services policy 108 with their digital signature 110 , the policy will include the administrator's signature. This signature may be used by the signature validity check 119 to ensure that the record is from the alleged author. In such cases, the creator may provide their public key for signature verification by the client. Method 200 also includes an act of the client computer system performing a time validity check to validate the trust services record's timestamp (act 220 ). Time validity check module 117 may perform the time validity check to ensure that the trust services record's timestamp is proper. Any or all of the trust services records 104 (e.g. records 105 - 108 ) may include a timestamp 109 with expiration date, a valid from field and a timestamp field. The expiration date indicates the date and time past which the record will no longer be valid. The valid from field indicates the first date and time from which the record can be valid, and the timestamp field indicates when the record was created (or last changed). The time validity check 117 includes verifying that the expiration date has not passed and/or verifying that the valid from field and timestamp fields have dates that are in the past. If the expiration date has not passed, and the valid from fields and timestamp fields are in the past, the record is valid, and may be indicated as such by the time validity check module 117 . Method 200 further includes an act of the client computer system performing an integrity check to validate the integrity of the trust services record (act 230 ). The integrity check module 118 of client computer system 115 may perform the integrity check. The integrity check may include constructing a record globally unique identifier (GUID) based on the trust services record's content and metadata and then comparing the record GUID with a previously generated record GUID corresponding to the same record. If the GUIDs do not match, then it can be inferred that the trust services record has been tampered with or altered in some manner. If such is the case, the record is filtered out and is discarded. Method 200 then includes an act of the client computer system performing a signature validity check to ensure that the entity claiming to have created the trust services record is the actual creator of the trust services record (act 240 ). The signature validity check module 119 may perform the signature validity check that ensures that the entity claiming to have created the record is the actual creator. The signature validity check may access the digital signature 110 to ensure that the signature is the expected signature and that it corresponds to the expected author of the record. Moreover, the signature validity check may verify that the trust services record was created by a trusted entity. It should be noted that while each of these checks has been described separately, each check may be used in combination with the other checks ( 117 - 119 ) or with other validation checks. The checks may be used in any order and at any time during client-server communication. FIG. 3 illustrates a flowchart of a method 300 for securely filtering trust services records. The method 300 will now be described with frequent reference to the components and data of environments 100 and 400 of FIGS. 1 and 4 , respectively. Method 300 includes an act of the client computer system receiving at least one of the following trust services records: a trust services certificate, a principal certificate, a group certificate and a trust services policy (act 310 ). As mentioned above, the receiving module 116 of client computer system 115 may receive trust services record 104 which includes trust services certificate 105 , principal certificate 106 , group certificate 107 and/or trust services policy 108 . The client computer system 115 may then perform one or more checks on the trust services record 104 including a time validity check to validate the trust services record's timestamp (act 320 ), an integrity check to validate the integrity of the trust services record (act 330 ) and a signature validity check to ensure that the entity claiming to have created the trust services record is the actual creator of the trust services record (act 340 ). Each of these checks is cryptographically provable and uniquely traceable to the creator. As such, the checks can be performed securely, with little to no risk that an outsider could insert a counterfeit trust services record. Method 300 also includes, based on the time validity check, the integrity check and the signature validity check, an act of determining that the trust services record is valid (act 350 ). For example, the record validation module 120 may determine that if trust services record 104 has passed each of the three aforementioned checks ( 117 - 119 ), that the record is valid. This validated trust services record 121 may then be used by a client 125 or other user to perform a specified task (act 360 ). The client may be a publisher who has published data to the cloud (or to another data store) or may be a subscriber who is accessing data from the cloud (or from another data store). Accordingly, the client 125 may publish data to the cloud, access data from the cloud, or perform some other specified task 126 using the validated trust services record 121 . As shown in FIG. 4 , trust services records 104 may be filtered by filter 450 (which may be similar to or the same as record validation module 120 ). Each check has a “Pass” box and a “Fail” box. If one or more of the checks fails, the trust services record will be labeled as a bad record 452 and will be filtered out and discarded (e.g. deleted or sent to trash bin 453 ). Records that pass each of the checks will be labeled as good records 451 and will be retained by the client computer system 115 . In this manner, records that have been tampered with, or are counterfeit, or are expired will be filtered out by at least one of the time validity check 117 , the integrity check 118 and the signature validity check 119 . If the client computer system 115 determines that a trust services record has been deleted by an entity, it will raise an error that prevents clear text data from being accessed by a third party. Thus, if the record is invalid from being altered, edited or deleted, the record will be filtered out and the user attempting to access data using the record will be prevented from doing so. Accordingly, methods, systems and computer program products are provided which securely filter trust services records. Because trust services records allow users to access data stored on the cloud, properly filtering out altered or counterfeit trust services records prevent unauthorized users from accessing other users' data, and will allow clients to securely store data on the cloud. The concepts and features described herein may be embodied in other specific forms without departing from their spirit or descriptive characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Embodiments include method, systems, and computer program products for filtering trust services records. Embodiments include receiving a trust services record that includes a plurality of security components and that is usable to secure data that is stored in an untrusted location. It is determined whether the trust services record has been tampered with, including verifying each of the plurality of security components of the trust services record. The trust services record is filtered based on the determination of whether the trust services record has been tampered with. The filtering includes, when the trust services record is determined to have not been tampered with, allowing performance of at least one task with respect to the secured data; and, when the trust services record is determined to have been tampered with, disallowing performance of any task with respect to the secured data.
7
This is a continuation of copending application Ser. No. 329,772, filed Dec. 11, 1981, abandoned. The present invention relates to an onsite system for treating oil-contaminated drill cuttings before disposal and more particularly relates to a method for treating such drill cuttings so that the treated cuttings can be disposed of without ecological risk. In a rotary drilling operation, a fluid commonly called "mud" is circulated from a storage area on the surface, downward through the drill pipe, out openings in the drill bit, and upward within the borehole to the surface. This return mud carries with it the drill cuttings from the bottom of the borehole. The returning mud along with its entrained drill cuttings is passed onto a "shale shaker" before it is returned to the storage area. The shaker, which normally sits above the mud storage area, is essentially a screen that is used to separate the drill cuttings and cavings from the mud. The mud falls by gravity through the screen and the cuttings pass over the end of the screen. Disposal of these separated cuttings is sometimes a real problem. When a drilling mud system such as an oil-base mud is used which coats the cuttings with undesirable contaminants, e.g., oil, the cuttings cannot be disposed of directly without the risk of polluting the area around the drilling site. Although the disposal of contaminated drill cuttings is complicated at an offshore location, it may also be a major problem at onshore locations where ecological considerations prevent the normal disposal of untreated cuttings. There are two general techniques for treating these contaminated cuttings to make them ecologically acceptable. Either they must be transported to disposal facilities or they must be treated on site to remove the contaminants before disposal. The added expense involved in transporting the cuttings from an offshore drill site is substantial, and accordingly, seriously detracts from widespread commercial application of this technique. Further, the technique of transporting the cuttings to shore for disposal may be impractical in areas of bad weather and rough seas. Therefore, for obvious reasons, it is much preferred to treat and dispose of the drill cuttings, especially for offshore operations, directly at the drilling site. To treat contaminated cuttings onsite, different types of methods have been proposed. One approach is to burn oil off the cuttings with high intensity lamps. However, this approach presents problems (i.e., possible fire hazards due to the lamps and the difficulty of equally exposing all the cuttings to the lamps) which makes it unfeasible in most instances. Another approach involves washing the cuttings with a detergent to remove the contaminants, separating the washing solution and contaminants, and dumping the clean cuttings into the water. One example of this approach is disclosed in U.S. Pat. No. 3,688,781 to William A. Talley, Jr. In a further approach as set forth in U.S. Pat. No. 4,209,381 to John Kelly, Jr., the contaminated cuttings are separated from the drilling mud and passed to a heating unit where they are sprayed with steam to flash distill the oil from the cuttings. The distilled oil and the spent steam are passed to a cooling unit where they are condensed before being passed to a water-oil separator. In a yet further approach, as set forth in U.S. Pat. No. 4,242,146 to John Kelly, Jr., the drill cuttings are sufficiently ground and mixed so that the contaminated oil is absorbed into the additional solid, oil-absorbent material of the cuttings themselves as exposed through the grinding. The ground and mixed cuttings are then compacted into pellets or briquettes before disposal to insure that the cuttings will safely sink to the bottom of the water into which they are disposed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view, partly in section, of an offshore drilling platform incorporating the present invention. FIG. 2 is a schematic of the drill cutting treating unit of FIG. 1 in accordance with the present invention. SUMMARY OF THE INVENTION The present invention is directed to a system for treating oil-contaminated drill cuttings from a well drilling operation in which a drilling fluid is circulated to remove drill cuttings from the well being drilled. A shaker separates the drill cuttings from the drilling mud. A holding tank collects the separated drill cuttings. A grinder increases the surface area of the drill cuttings to expose additional solid oil-absorbent material. A mixer enhances the absorption of free oil into the additional solid, oil-absorbent material exposed through the increased surface area of the ground cuttings. In a further aspect, a controlled amount of additional solid oil-absorbent material is added to the holding tank and a stirring member within the holding tank blends the drill cuttings with the added solid oil-absorbent material. A conveyor transports the blended drill cuttings to the grinder. A portion of the blended drill cuttings is diverted back into the holding tank to enhance the blending process. The rate of flow of the blended drill cuttings from the holding tank to the grinder is controlled so that the rate of disposal of the drill cuttings is no less than the sum of the rate at which the drill cuttings are being produced plus the rate at which the oil-absorbent material is being added. In a still further aspect, the conveyor between the holding tank and grinder is a blending conveyor. Additional solid, oil-absorbent material may be added to the blending conveyor, whereby the drill cuttings are blended with the added solid, oil-absorbent material as they are being transported from the holding tank to the grinder. In a yet further aspect, a compactor presses the ground cuttings into individual masses having sufficient density to sink in water. A screen separates from the compacted cuttings the fine materials which do not have the desired quality for disposal into the water. The fine materials separated from the compacted drill cuttings are recycled through at least some portion of the treating system. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there will be described a well drilling operation with which the treating system of the present invention may be utilized. A typical offshore drilling rig 10 has a platform 11 supported on marine bottom 12 of the body of water 13 by means of legs 14. A derrick 15 is mounted on platform 11 which is used to carry out normal rotary drilling operations. Although a fixed offshore platform is shown for illustrative purposes, it should be realized that the present invention can be used equally as well with other offshore drilling operations, e.g., floating drilling vessels or submergible barge platforms, as well as with onshore drilling operations. In rotary drilling operations, a fluid, commonly mud, is circulated into and out of the hole being drilled for a number of reasons, one being to carry drill cuttings out of the borehole. A typical, well known mud circulation system for a rotary drilling operation is partially illustrated in FIG. 1. A conductor pipe 21 extends from platform 11 into marine bottom 12. Mud is circulated down a drill string (not shown) which is positioned in and extends through conductor pipe 21. The mud exits from the drill pipe through openings in a drill bit (not shown) on the lower end of the drill pipe and flows upward through conductor pipe 21 to mud return line 24. The mud carries drill cuttings with it back to the surface. As is well known in the art, the mud exits mud return line 24 and flows through shale shakers, desanders, desilters, hydrocyclones, centrifuges, and/or other known devices of a treating unit 27 to separate the cuttings from the mud. The mud is then returned to a storage area (not shown) for reuse. Where the mud being used does not coat the cuttings with any undesirable contaminants, the cuttings are sometimes returned directly to the body of water 13 or are disposed of in some other manner. However, as is often the case, a special mud system has to be employed in certain drilling operations, both offshore and onshore, which coats the cuttings with contaminants. This presents serious problems in disposing of the cuttings. For example, in offshore operations, the contaminants may wash free when the cuttings are returned to the water, thereby causing undesirable pollution problems. An example of such a mud system is one commonly called an "oil-base" mud system. The mud used in this system coats the cuttings with oil which remains adhered thereto even after the cuttings are mechanically separated from the mud. If these cuttings are returned untreated to the water, some of the oil most likely will wash off and may form an oil slick on the water. Also, in some instances, the cuttings, after separation, are "washed" with diesel or other suitable oil to remove whole mud and other chemical contaminants therefrom. However, some of the diesel or other oil is likely to adhere to the cuttings which complicates their disposal. The contaminated cuttings, after being separated from the mud by the treating unit 27, may be further treated with one or more of the techniques set forth and described in the aforementioned U.S. Pat. Nos. 3,688,781; 4,209,381; and 4,242,146. It may be particularly desirable, as a final step in the treating process, to compact the mixture of cuttings into pellets or briquettes of sufficient density to sink in water as described in U.S. Pat. No. 4,242,146. Any of several known, commercially available compactors which compact a solid mixture and extrude the mixture as pellets or briquettes, may be employed, one such compactor being the K-G Briquetting System sold by Komarek-Greaves and Co., Rosemont, Ill. The treated, and preferably compacted cuttings, pass to the discharge member 30 for conveying the treated and compacted cuttings from the drill platform to the ocean. It is a specific feature of the present invention to provide for a discharge member which allows the cuttings to enter the water without being broken up or disintegrated from impact or other contact with the discharge member itself, the drill platform, the platform support legs and pilings, or the water itself. In this manner the cuttings can be disposed of in the ocean with minimum pollution to the area around the drilling site with oil from the cuttings. The discharge member 30 may be a vertical member for disposing of the cuttings directly downward beside the drill platform or may be inclined from the vertical along some portion of its pathway so as to carrying the cuttings away from the drill platform. By disposing of the cuttings at some distance from the platform, the possibility of break-up of the cuttings upon impact with the platform or the pilings around the base of the platform is eliminated. Having described a well drilling operation in conjunction with FIG. 1, with which the present invention may be utilized, reference may now be made to FIG. 2 illustrating the treating system for oil-contaminated drill cuttings of the present invention. Referring now to FIG. 2, the oil-contaminated drill cuttings from the well drilling operation pass through the mud return line to one or more of a plurality of shakers 40. These shakers permit the mud fluid to pass through the shaker screens while leaving the drill cuttings on top of the screen. The cuttings are conveyed from the shakers 40 to a holding tank 41 by means of a suitable conveyor 42 such as, for example, a screw feed conveyor for providing some blending of the drill cuttings during transport. Such drill cuttings may comprise either sandy material or shale material, or both. The tank 41 may preferably include a stirring member for mixing and blending any sandy material present with any shale material present. The tank 41 further serves to distribute the drill cuttings at a uniform rate to the rest of the treating system even though the production rate of the drill cuttings increases or decreases with time depending upon the well drilling operation. From tank 41, the drill cuttings travel by means of a further blending conveyor 43 to a grinder, or crusher. This grinder breaks up the drill cuttings into smaller particles to provide an increased surface area for the further absorption of the contaminating free oil on the cuttings. From the grinder 44, the cuttings pass to a mixer-muller 45 which provides for further mixing of the cuttings to cause absorption of any of the free oil into the cuttings which was not absorbed during the mixing that is inherent in the grinding process. Mixer-muller 45 can also provide for additional grinding if yet additional surface area is required for further absorption of the free oil present. From the mixer-muller 45, the drill cuttings are transported to the compactor 46 which compacts the cuttings and extrudes them as pellets or briquettes. The pellets or briquettes then pass over a screen 47 which serves to separate out those pellets, briquettes, or other fine material having insufficient size to sink in water at a rapid enough rate to prevent their carriage away from the area surrounding the drill platform by ocean currents, those fine materials being recycled through the treating system. Having described the flow of the oil-contaminated drill cuttings through the various components of the treating system, the operation of the system will now be described in more detail with respect to the flow rate through the system and the addition of any absorbent or surfactant materials for aiding in the free oil absorption process. During drilling operation, if there is sufficient shale in the drill cuttings, the grinding process will provide enough additional solid absorbent surface area to absorb the free oil contaminating the drill cuttings. However, if there is too much sand present in the drill cuttings, the pellets or briquettes from the compacting process will be too sandy, or too wet, and will not hold together on the final screening step or upon impact with the water. In this event, a solid absorbent material such as a clay, for example, is blended with the drill cuttings so that the grinder 44 and mixer-muller 45 will provide drill cuttings of sufficient composition and dryness to allow the compactor to produce pellets or briquettes that will not break up or disintegrate. This absorbent material may be added and blended with the drill cuttings in the holding tank 41 and also in the blending conveyor 43. A metering conveyor 49 can be activated to supply a desired rate of absorbent material flow from an absorbent supply 50 into the holding tank 41 and a metering conveyor 51 can be activated to supply a desired rate of absorbent flow from absorbent supply 50 to the blending conveyor 43. Referring again to the discharge of the drill cuttings into the water, the compacted drill cuttings need to be of sufficient composition to resist break-up and disintegration and also to have sufficient densities to sink to the water bottom. It is therefore important that any fine material exiting from the compactor 46 along with the desired pellets and briquettes, be separated and recycled through at least a portion of the treating system and reprocessed so that they will not contaminate the water surrounding the drill platform. The screen 47 may selectively pass to discharge only those pellets or briquettes of one-quarter to one-half inch in size, for example. A conveyor 55 carries these separated fine materials preferably back to the holding tank 41 where they may be recycled through the entire treating system. However, it is apparent that such recycling could be designed to carry the fine materials back to any portion of the system as desired, even to the extent of recycling just through the compactor 46. Having now described the flow of the drill cuttings, absorbent material and fine material through the treating system, the rate at which such cuttings and materials flow through the system will be described. An important aspect of the invention is to be able to discharge treated drill cuttings from the system at the same rate, or faster, than the rate at which the oil-contaminated drill cuttings are being drilled. Otherwise, storage would have to be provided for the untreated cuttings, which could be quite a problem on an offshore drill platform. In one embodiment, the treating system is designed to process up to 40 tons of drill cuttings per hour. Referring again to FIG. 2, up to 40 tons of drill cuttings per hour can pass from the shaker 40 into the holding tank 41. Also entering the holding tank 41 is the fine material from the screen 47 which, in this embodiment, is about 8 tons per hour. From the absorbent supply 50 up to 8 tons per hour of absorbent material can be metered into the holding tank 41 or onto the blending conveyor 43 as needed. From the blending conveyor 43 up to 10 tons per hour of mixed drill cuttings, absorbent material and fine material can be recycled by means of conveyor 56 back into holding tank 41 to further aid in the mixing or blending within the holding tank. Therefore, 56 tons of the blended drill cuttings per hour will be processed through the grinder 44, mixer-muller 45, compactor 46 and screen 47. Since the screen 47 will separate out each hour the previously mentioned 8 tons of fine materials, 48 tons per hour of treated drill cuttings are disposed into the water. This 48 ton per hour discharge rate of treated drill cuttings corresponds to the total input rate to the system of 40 tons per hour of drill cuttings and 8 tons per hour of added absorbent material. Again, the important feature is to be able to treat and dispose of the drill cuttings at the rate at which they are being produced. However, fluctuations in the drilling rate can be temporarily handled within the holding tank 41. Ideally the holding tank will be filled to about 20 to 30 percent capacity. Should the drilling rate decrease such that, in the particular embodiment described herein, less than 40 tons per hour of drill cuttings are being produced, the level of the holding tank will lower and the treating system can be turned off until the level again rises. Should the drilling rate, again in the particular embodiment herein, exceed 40 tons per hour of drill cuttings, the level within the holding tank will rise. In the event the holding tank begins to reach its capacity and the drilling rate does not decrease, a separate storage facility would have to be made available, or preferably, a separate and parallel treating system would have to be available on the drill platform for activation to handle the overload of drill cuttings, otherwise the drilling would have to be shut down until the level in the holding tank reaches a level whereby drilling could be resumed. As can be seen from the foregoing, the present invention provides a safe, reliable system for treating oil-contaminated drill cuttings from drilling operations. While a particular embodiment for the system has been described above, many modifications and variations may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
A system for treating oil-contaminated drill cuttings includes a grinder for increasing the surface area of the drill cuttings to enhance the absorption of free oil on the cuttings. A mixer enhances the absorption of free oil into the additional solid, oil-absorbent material exposed through the increased surface area of the ground cuttings. After mixing, the ground cuttings may be compacted into individual masses of sufficient density to sink in water. Fine materials are separated from said compacted masses prior to disposal in a marine environment.
1
This Application is a continuation-in-part of copending Application Ser. No. 373,730 filed Apr. 30, 1982 now U.S. Pat. No. 4,414,826. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guidebar shogging apparatus for warp knitting machines and the like and, in particular, to an apparatus that is adjustable and automatically programmable in fixed increments that are proportional to the knitting machine needle spacing. 2. Discussion of the Relevant Art As is shown in the disclosure of our co-pending parent Application Ser. No. 373,730 filed Apr. 30, 1982, the ordered control elements can be displaced in a substantially frictionless manner while the guide bars and paths of the summation drive are in force-transferring contact. This permits substantially higher working speeds that have been customary with those summation drives wherein the guide bars have to be taken out of contact with the summation drive when the control arrangement is activated. There is a need to provide an arrangement of the previously described type which is improved in such a way as to increase the availability of different types of patterns to be produced by the machine. SUMMARY OF THE INVENTION A summing arrangement for controlling the underlap and overlap motions of a guide bar of a warp knitting machine has a plurality of ordered elements. Each of these elements has at least one bearing face and each is mounted in the machine to allow a variation in the spacing between each. Also included is a plurality of spreading means. A different corresponding one of the spreading means is engaged between each adjacent pair of the elements for pushing at least one of the elements at its bearing face. The summing arrangement also employs a control means having an underlap and an overlap arrangement. This control means is coupled to the plurality of spreading means for operating them according to a predetermined pattern to influence the underlap motions. The overlap arrangement is operable to move against at least a predetermined one of the ordered elements to influence each of the overlap motions. According to a related method of the same invention the overlap and underlap motions of a guide bar are controlled and driven by a plurality of ordered elements having an adjustable composite length. The method includes the step of adjusting the spacing between predetermined ones of the elements to produce the underlap motion. The method also includes the step of moving at least a predetermined one of the elements to influence each of the overlap motions. By using apparatus and methods of the foregoing type an improved control arrangement is provided which may be so activated during the appropriate portion of the working cycle that it performs an underlap displacement and causes a displacement during the appropriate time of the working cycle to perform one overlap displacement. Preferably, during a working cycle, control arrangements influence a summation arrangement and may be timely displaced so that there is provide an underlap displacement and an overlap displacement. Both are desirable for patterning. The summation drive permits the size and direction of the underlap displacement to be varied. Preferably the control arrangement for the overlap displacement is constructed in the same manner as that for the underlap displacement control arrangement. Suitably, the overlap displacement control arrangements have a similar impulse roller which can work substantially without frictional burdens. In the preferred embodiment of the invention, at least one of the underlap displacement control arrangements may simultaneously serve as an overlap displacement control direction in that it is activatable during the course of the work cycle so that it can perform either an underlap displacement and/or an overlap displacement. This reduces the complexity for the overlap displacement. A twofold use of the work cycle may be put into effect without further technical control problems. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which: FIG. 1 is a schematic side elevational view of a first embodiment of an arrangement in accordance with the present invention; FIG. 2 is a schematic side elevational view of a second embodiment in accordance with the present invention; FIG. 3 is a partial cross-sectional view along lines III--III of FIG. 1; FIG. 4 is a partial lapping diagram showing the underlap and overlap occurring in one work cycle; and FIG. 5 is a timing diagram showing the underlap and overlap times. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, its upper portion is substantially equivalent to the apparatus shown in FIG. 3 of copending Application Ser. No. 373,730 filed Apr. 30, 1982. Hence the same components will be designated with the same reference numbers. Guide bar 201 carries a plurality of spaced, parallel, conventional guides 202 and is biased by tension spring 203. Thread guide bar 201 is mounted to slide longitudinally and perform a shogging motion. One end of spring 203 is held by a fixed support 204 and its other end connects to and acts upon guide bar 201 via connecting means 205, an upright bar attached to one end of guide bar 201. Rod 206 is held in contact with the guide bar 201 via roller bearing 207. The other end of rod 206 is held via roller bearing 208 against the free end 209 of summing arrangement 210. This summing drive 210 comprises seven ordered elements, 211 through 217 in the shape of blocks which are longitudinally slidable in fixed guideway 218. Element 217 has inside curved displacement surface 219, whose two end plateaus 220 and 221 represent the extremes of displacement caused by surface 219 to element 217. A plurality of spreading means is shown employing roller means 222 and 234, illustrated in FIG. 1 and in more detail in FIG. 3. Rollers 222 are a pair of spaced coaxial rollers mounted on common axis 235. Mounted between roller pair 222 on the same axle 235 is roller 234, structured the same as rollers 222. Rollers 222 roll on surface 219 of element 217. Since surface 219 has a shallow groove aligned with roller 234 (FIG. 3) roller 234 does not engage surface 217 and instead rotates independently of rollers 222. The axle of axis 235 is supported by the forked upper end of connecting rod 225 whose lower end terminates in circumferential ring 226. Rod 225 can be reciprocated by eccentric rotation of eccentric cam 227 within circumferential ring 226. Cam 227 is rigidly affixed to shaft 228. Impulse roller 234 rolls on the central ridge (FIG. 3) of running surface 233. This running surface 233 also serves as a displacement curve and is oriented conversely (mirror-image) to that of displacement surface 219. Because it is ridged, surface 233 does not engage rollers 222. When cam 227 is rotated 180° from the bottom position to the illustrated upper position, the impulse rollers 222 and 234 move upwardly, across surfaces 219 and 233, respectively, whereby element 217 is moved to the left by 16T units relative to element 216 (wherein T corresponds to one needle space of the needle bar). The foregoing described a portion of an underlap displacement control arrangement 236. The other underlap control arrangements 237, 238, 239, 240 and 241, operate in a similar manner. Each have a similar structure employing an eccentric cam driving the lower circumferential ring of a connecting rod whose forked upper end supports three coaxial rollers. The rollers of arrangement 237 are between elements 216 and 215. The rollers of arrangements 237, 238, 239, 240 and 241 are positioned in front of ordered elements 215, 214, 213, 212 and 211, respectively. Each of the elements 211-217 is slidably mounted in guideway 218. However, arrangement 237 provides a displacement of 16T units, arrangement 238 a displacement of 8T units, arrangement 239 a displacement of 4T units, arrangement 240 a displacement of 2T units, and arrangement 241 a displacement of 1T unit. Thus, it is possible to provide for a guide bar displacement of between 1T and 47T units. There is further provided an overlap displacement arrangement 242. This is structurally equivalent to the underlap displacement control arrangement described herein above. Specifically arrangement 242 comprises a pushing means including an eccentric cam 242b rotatable within the lower ring of rod 242a whose forked upper end supports three coaxial rollers. However, in this case, the impulse rollers of rod 242a rest in part, against a supplemental element 244 fixed within guideway 218 so that by activation of the overlap displacement control arrangement 242, resistance surface 243 on displaceable element 211 (namely the resistance surface of the outermost underlap displacement setting arrangement 241) is displaced. This setting arrangement 242 may thus cause a displacement of 1U which corresponds to one needle space in the overlap setting. A control means is shown connected to the shafts of arrangements 236-242 to rotate them, reciprocate their rods and change the spacing between elements 211-217 and 244. All shafts, such as shaft 228, are activatable by a shaft 245 running at main shaft rotation speed. Shaft 245 is coupled to couplers 246 through 252 which have an output for driving the cams of arrangements 236 through 242, respectively. Couplers 246-251 are part of a underlap arrangement, coupler 252 being part of an overlap arrangement. All couplers are controlled by electrical control signals emanating from the program arrangement 253. Upon provision of such a control signal, one or more of the appropriate shafts, such as shafts 228, turns through an angle of 180° in the direction of arrow Z. This rotation causes a displacement of the impulse roller from the lower position to the upper position or the reverse. Program arrangement 253 may take the form of a computer such as a mirocomputer having sufficient memory to produce a pattern of output signals to couplers 246-252. The pattern is preferably updated before the end of each cycle of shaft 245. Computer 253 may have a transducer coupled to the main shaft 245 to trigger the computer and cause the above mentioned updating. The choice of the control arrangement to be activated can be provided either by means of a jacquard apparatus, an electronic program controller, or the like. The desired correct activation time point may be readily provided by the main shaft 245 of the machine. It is particularly advantageous if both the underlap displacement control arrangement 246-251 as well as the overlap displacement control arrangement 252 is activated by a program steerable coupling. Such a program steerable coupling can be activated either by a simple instruction and thus lead to a displacement of the appropriate control arrangement. By means of programs both the appropriate underlap displacements as well as the overlap displacements may be utilized to provide a variety of desired patterns. In the embodiment of FIG. 1, the overlap control arrangement 242 need not be located at the end of the summing drive but may also be located at another position. However, it is advantageous to provide the overlap displacement control arrangement 242 at the support surface of the first (or outermost) underlap displacement control arrangement, which may be located at the end of the summation drive furthest away from the guide bar. In this way the rest of the summation drive may remain undisturbed. Also, it is desirable to provide the support surface on an element (e.g. surface 243 of element 211) displaceable in the direction of the drive by an impulse roller of the overlap displacement control arrangement. The overlap displacement control arrangement thus has practically the same construction as the underlap displacement control arrangement. This leads to a readier and simpler form of construction. In the modification of FIG. 2, many of the same parts are utilized as those in FIG. 1. Similar parts are therefore shown increased by one unit in the one hundreds digit. The system may, however, be differentiated in that the running surface 333 for the impulse roller of first underlap control arrangement 341, is formed by the angled head surface of a displaceable slider 356 set at an angle to the drive displacement direction of the underlap setting arrangement 342. Slider 356 carries at its upper outside end impulse roller 357 which is contacted by control cam 358. Cam 358 is supported by shaft 359 which rotates at 1/4 of the rate of rotation of the main shaft (shaft 245 of FIG. 1). Cam 358 has four protrusions 360. Thus during each work cycle there is provided a reciprocating overlap movement of one needle space, i.e. 1U. Slider 356 will be urged against cam 358 by the same spring forces described in connection with FIG. 1. There exists another possibility in that the overlap displacement control arrangement is activated either by the above illustrated control cam or control chain. In either case, the patterning caused by the overlap displacement is limited to the instructions carried by the appropriately chosen control cam or chain. However, in most cases this has been found adequate. It is advantageous to provide support surface 333 as the angled face surface of slider 356, which is angularly displaceable with respect to the drive displacement direction of the overlap displacement control arrangement. Such a control arrangement may be added to an already constructed summation drive. In an arrangement such as the foregoing, the overlap displacement can be in the same direction, reversal occurring preferably during underlap. It is further advantageous if, for the maintainence of the direction of the overlap displacement direction in sequential working cycles, the overlap displacement setting arrangement 342 is simultaneously activatable with the underlap displacement control arrangement 336-341. This permits the overlap displacement control arrangement 342 to return to the starting position it held in the previous work cycle. In this latter control movement, the actual underlap displacement is different than the one obtained by utilizing the regular underlap displacement control arrangement alone. In operation, guide bar 201 may be displaced as shown by the ordinate of the timing diagram of FIG. 5. This diagram may be considered the motion intervals corresponding to the magnitude of shogging velocity. In the following description the apparatus of FIG. 1 will be considered, although the operation of the apparatus of FIG. 2 will be similar except its overlap motion will be defined by its cam 358. In FIG. 5, it will be seen that each work cycle, comprises a 360° rotation (abscissa) of main shaft 245 (FIG. 1). During period A which, for example, runs from 0° to 110°, there is provided an underlap and during a period B which similarly runs from 185° to 220° there is provided an overlap. In FIG. 4, there are illustrated a plurality of needles 254 and a line 255 schematically illustrating the travel path of guide 201 (FIG. 1). In this example it is assumed that prior to time Ao all arrangements 236-242 are retracted to provide the minimum spacing between elements 217 and 244. The activation of the underlap displacement control arrangements 236-241 by the appropriate couplings 246-251 are initiated at the beginning of the underlap period A, that is to say at point Ao or shortly before. In this example, at time point Ao, the underlap displacement control arrangement 240 and 241 are activated so that an underlap displacement of 3T occurs. At time Ao computer 253 energizes couplers 250 and 251. Accordingly, shaft 245 causes rotation of the cams and lifting of the rollers of arrangements 240 and 241 during interval A. Arrangements 240 and 241 provide displacements to guide 201 of 2T and 1T, respectively, for the total displacement of 3T shown in FIG. 4. This causes an underlap motion in front of the needles (not shown). After interval A, guide bar 201 may swing backwardly, completing the swing before time Bo. At time point Bo the overlap displacement control arrangement 242 is activated to provide an overlap of 1U in the same direction as underlap motion 3T, in this cycle. To this end computer 253 energizes coupler 252 to crank cam 242b 180°, thereby raising rod 242a to the position shown in FIG. 1. This cranking shogs guide bar 201 and provides an overlap motion occurring over approximately 35° of rotation of main shaft 245. As noted, the activation of the overlap displacement control arrangement 242 by the appropriate coupling 252 commences at the beginning of the underlap period B, that is to say at time point Bo or shortly before. Thus, the activation time points Ao and Bo occur approximately 185° relative to each other. After interval B the knitting machine may perform a stitch before the start of the next cycle. The coupler 252 of the appropriate main shaft 245 may turn around 180° with greater speed than the other couplers since for overlap a smaller rotational angle of the work cycle is available than for the underlap. In this example, this is between 185° and 220° as opposed to 0° through 110°. Since the overlap movement usually comprises at the most two needle spaces, it is no great problem to achieve this displacement during the work angle B of FIG. 5. On the other hand, in an underlap when one has the displacement of 4, 8 or 16T, a longer time is necessary. The angular displacements in FIG. 5 preferably have substantially the shown size and position. They may, however, be somewhat varied. For example, the length of segment A may lie between 100° and 120° and segment B may lie between 30 and 40°. The displacements in the next work cycle would depend upon the desired pattern. If it is desired in the next work cycle that the overlap displacement will proceed in an opposite direction, the overlap displacement setting arrangement 242 can be reversed in the next time interval B. On the other hand, if it is desired that in the next work cycle the overlap displacement direction proceed in the same direction, then the overlap displacement control arrangement 242 is activated at time point Ao so that at time point Bo it may again provide the same overlap displacement as it did in the previous cycle. This movement of the overlap displacement control arrangement 242 at time point Ao can be compensated in that the underlap displacement provided by control arrangement 236-241 are increased by 1T unit with respect to the actually desired underlap displacement. For example, it an extension of 3T units is required (that is a total of 7T units, taking into account the prior underlap of 3T and overlap of 1U) arrangements 239 and 242 will be actuated by computer 253. As a result, arrangement 239 will provide a displacement of 4T, but the opposite displacement of arrangement 242 of 1U produces a net displacement of 3T. Therefore arrangement 242 has been retracted and is a condition to raise rod 242a during the succeeding overlap interval B so that two succeeding overlap intervals work with shogging motions in the same direction. The embodiment of FIG. 1 can also be activated in such a way that no sharp division is made between the control arrangement 236-241 provided for the underlap displacement and the control arrangement 242 providing for overlap displacement. In fact, the control arrangement 242 can be so activated in dependence upon a program to provide for underlap displacement at time point Ao, provided this activation of arrangement 242 is consistent with the overlap motion required in the next interval B. During the above-described process example, there is an overlap displacement during each working cycle. If desired, however, one can interrupt the automatic overlap displacement so that the pattern threads may float. By means of the present invention, it is thus possible not only to achieve an underlap displacement, but also an overlap displacement as often as desired, or not at all, and in the desired direction, at higher machine speeds than has heretofore been possible. It will be understood that various changes in the details, materials, arrangement of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of instant invention.
A summing arrangement controls the underlap and overlap movement of a guide bar of a warp knitting machine. The arrangement has a plurality of ordered elements each having at least one curved face. The ordered elements are mounted on the machine to allow a variation in the spacing between each. Also included is a plurality of adjustable roller devices, one between each adjacent pair of elements. Each of these roller devices can roll upon and push at least one of the elements at its curved face. An overlap arrangement can move against at least one of the ordered elements to influence each overlap movement.
3
CROSS REFRENCE TO RELATED APPLICATIONS [0001] This application claims benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 61/1311,266, filed Mar. 5, 2010. FIELD OF THE INVENTION [0002] The present invention relates to fasteners used for fastening a fabric cover to surfaces of a vehicle. BACKGROUND OF THE INVENTION [0003] It is well known to provide fabric covers which engage over the grill of a vehicle. Such covers can be imperforate for acting as a winter front to reduce the amount of cooling air passing through the grill or can constitute a bug screen in which case the fabric cover is formed from a perforated screen material to allow air to flow through while preventing passing of insects and other debris. [0004] It is also well known to provide a cover for the box of a pick-up truck which is known as a tonneau cover. [0005] In many cases these fabric covers are fastened using press fasteners which comprise a female cap member attached to the fabric cover around a peripheral edge portion thereof together with a male stud member which has a peripheral rim extending into the cap member for readily releasable and reengageable snap fastening arrangements. A plurality of such fasteners are arranged at spaced positions around the periphery of the fabric cover. Such arrangements have been manufactured and widely sold for many years. [0006] On prior art technique for attachment of the male stud member to a surface of the vehicle involves drilling a hole in the vehicle surface and using a self-tapping screw engaged through a central hole in the stud member to clamp the stud member to the vehicle surface. However this technique has a significant disadvantage that the vehicle owner in many cases does not want to perforate the vehicle surface in view of the difficulties which can be caused to the rust and corrosion prevention coatings of the surface. There is a reluctance therefore to purchase covers of this type which require the user to drill holes in the vehicle surface. [0007] One solution which has been provided therefore in regard to the tonneau cover on the truck box is to manufacture a rail system which is initially attached to the vehicle using openings already available in the vehicle following which the tonneau cover is attached to the rails using the conventional press fastener systems. This system however of course requires significant extra parts to be manufactured, transported and assembled for the finished product. However the reluctance of users to perforate the vehicle surface has lead to such complex solutions to this long standing problem. [0008] Applicant's U.S. Pat. No. 5,797,643, incorporated herein by reference, outlined a further solution in which a male stud portion having a rigid disc-shaped base and a cylinder projecting from one side of the disc to carry the peripheral engagement rim is adhesively secured to the vehicle surface, either by an adhesive layer fixed directly to the bottom surface of the disc or an adhesive layer fixed to a bottom surface of a flexible plastic sheet to which the male stud portion can be engaged by fitting a stud member on the flexible sheet through a hole in the disc of the male stud portion. The disc of the male stud portion can be mounted directly when the vehicle surface in question is flat, but the separate stud-equipped flexible sheet is needed to mounted the rigid male portion on an arcuate or curved surface. [0009] The present invention improves on the prior art by providing a one-piece male stud portion that can be mounted to flat, curved or bent surfaces without requiring a separate piece for accomplishing the adhesive attachment to the vehicle surface. SUMMARY OF THE INVENTION [0010] According to a first aspect of the invention there is provided a vehicle comprising: [0011] a vehicle body having at least one opening therein to be covered; [0012] a plurality of vehicle surfaces arranged around said at least one opening; [0013] a fabric cover for engaging over the opening and having edge portions for engaging respective ones of the vehicle surfaces; and a plurality of fastening elements for fastening the edge portions to the respective vehicle surfaces; [0014] each fastening element comprising: a female cap member attached to a respective fabric edge portion; a unitary male stud member having a flexible base portion and a projecting portion integral therewith, a peripheral rim of the projecting portion standing upwardly from the base portion and being engageable into the cap member as a readily releasable and reengageable snap fastener and a bottom surface of the flexible base portion opposite the projecting portion following a curvature of the respective vehicle surface; and a layer of adhesive having one surface adhesively fastened to the bottom surface of the base portion and an opposed surface fastened to the respective vehicle surface; [0018] wherein at least one of the respective vehicle surfaces is non-planar and at least some of the bottom surface of the flexible base portion on said one of the respective vehicle surfaces is deformed to conform thereto. [0019] According to a second aspect of the invention there is provided an apparatus comprising: [0020] a body having a portion thereon to be covered; [0021] a plurality of body surfaces arranged around said portion; [0022] a fabric cover for engaging over the portion and having edge portions for engaging respective ones of the body surfaces; and [0023] a plurality of fastening elements for fastening the edge portions to the respective body surfaces; [0024] each fastening element comprising: a female cap member attached to a respective fabric edge portion; a unitary male stud member having a flexible base portion and a projecting portion integral therewith, a peripheral rim of the projecting portion standing upwardly from the base portion and being engageable into the cap member as a readily releasable and reengageable snap fastener and a bottom surface of the flexible base portion opposite the projecting portion following a curvature of the respective body surface; and [0027] a layer of adhesive having one surface adhesively fastened to the flexible attachment member and an opposed surface fastened to the respective body surface; [0028] wherein at least one of the respective body surfaces is non-planar and at least some of the bottom surface of the flexible base portion on said one of the respective body surfaces is deformed to conform thereto. [0029] According to a third aspect of the invention there is provided a kit of parts for attachment of a cover to a vehicle comprising: [0030] a fabric cover for engaging over a portion of the vehicle and having edge portions for engaging respective vehicle surfaces; [0031] a plurality of fastening elements for fastening the edge portions to the respective vehicle surfaces; [0032] each fastening element comprising: a female cap member attached to a respective fabric edge portion; a plurality of male fastening elements, each comprising a unitary male stud member having a flexible base portion and a projecting portion integral therewith, a peripheral rim of the projecting portion standing upwardly from the base portion and being engageable into the cap member as a readily releasable and reengageable snap fastener, a bottom surface of the flexible base opposite the projection portion being deformable relative to the projecting portion; and a layer of adhesive having one surface adhesively fastened to the flexible attachment member and an opposed surface and an opposed surface covered by a removable covering layer and exposable by removal of the covering later for fastening to the respective vehicle surface. [0036] According to a fourth aspect of the invention there is provided a fastening element comprising: [0037] a female cap member; [0038] a unitary stud body defining a flexible base portion and a projecting portion integral therewith, a peripheral rim of the projecting portion standing upwardly from the base portion and being engageable into the female cap member as a readily releasable and reengageable snap fastener, a bottom surface of the flexible base opposite the projection portion being deformable relative to the projecting portion; and [0039] a layer of adhesive having one surface adhesively fastened to the bottom surface of the flexible base portion and an opposed surface covered by a removable covering layer and exposable by removal of the covering later for fastening to a surface of a body on which the snap fastener is to be used. [0040] Preferably the flexible base portion has a plurality grooves formed therein and each extending fully across the base portion. [0041] Preferably the grooves are formed in a top surface of the base portion opposite the bottom surface thereof. [0042] Preferably the grooves are formed on opposite sides of the projecting portion. [0043] Preferably the grooves are parallel with one another. [0044] In use of the fastening element, said one of the respective vehicle surfaces may feature a bend from which portions of said one of the respective surfaces diverge, one of the grooves in the flexible base portion on said one of the respective vehicle surfaces extending along said bend with the flexible base portion bending across the groove. [0045] Preferably the projecting portion of each fastening element has a first outer diameter from which the peripheral rim projects outwardly and has a second outer diameter smaller than the first outer diameter where the flexible base connects to the projecting portion integral therewith. [0046] Preferably the projecting portion of each fastening element is hollow and a hollow interior of the projecting portion is open at a top end thereof opposite the base and closed at a bottom end thereof by the base. BRIEF DESCRIPTION OF THE DRAWINGS [0047] In the accompanying drawings, which illustrate an exemplary embodiment of the present invention: [0048] FIG. 1 is an isometric view showing simply a vehicle of the type having a vertical front grill and an open rear box with the front grill covered by a fabric cover and the box cover covered by a tonneau cover. [0049] FIG. 2 is a cross sectional view showing one of the fastening elements by which the covers are fastened to the vehicle surfaces installed on a flat one of those surfaces. [0050] FIG. 3A is a vertical cross sectional view through the male stud of a second fastening element installed on a bent vehicle surface. [0051] FIG. 3B is a vertical cross sectional view through the male stud of a third fastening element installed on a curved vehicle surface. [0052] FIG. 4 shows a kit of parts which can be purchased by a user for attachment to a vehicle of the type shown in FIG. 1 . DETAILED DESCRIPTION [0053] In FIG. 1 shows a vehicle which is generally indicated at 10 and is of the pick-up truck type including a nearly vertical upright front grill 11 and a rear box 12 . The front grill 11 is covered by a fabric panel 13 and the box is covered by a tonneau cover 14 . The vehicle is of conventional construction and shown only schematically. The covers 13 and 14 are also shown only schematically as these are well known to one skilled in the art and can vary in accordance with the requirements. [0054] The present invention is concerned with the technique for fastening the covers 13 and 14 to the vehicle, and the elements for forming this fastening technique are shown in FIGS. 2 , 3 and 4 . Thus in FIG. 4 is shown one of the covers which is generally indicated at 15 comprising a fabric sheet 16 and a plurality of female cap-type fasteners 17 . Also in FIG. 4 is shown a male fastener generally indicated at 28 . Further details of the male fastener 28 are shown in FIGS. 2 and 3 . [0055] In general each of the fasteners is of a type best shown in FIG. 2 . In this type of fastening arrangement, there is provided a female cap portion 17 which defines a relatively shallow cap having a female recess 18 and a peripheral engagement rim 19 surrounding the recess 18 . The fabric 16 has portions 16 A clamped to the cap 17 , and in the arrangement shown this is effected by an outer cap section 20 which pinches the portion 16 A between the outer cap section 20 and an inner cap section 21 defining the recess 18 . The female cap 17 cooperates with the male portion 28 in a snap fastening arrangement. [0056] The male portion 28 is a single, unitary, integral piece made of a single material that defines a flexible disc 30 , which has a bottom circular surface 31 , and an upstanding fastening portion 32 with an engagement rim 33 . The rim 19 of the cap 17 is thus arranged as a snap-fit over the rim 33 of the upstanding projecting portion 32 . The flexible circular disc 30 underlies and surrounds the cylindrical portion and projects outwardly therefrom. The flexible disc and upstanding fastening portion 32 are seamlessly integral with one another as a result of the one-piece construction of the male portion 28 , as opposed to the seam that would result from instead trying to produce a similar structure by fastening two originally-separate pieces together to form a flexible base on a significantly more rigid piece carrying the fastening portion. [0057] In the installed arrangement shown in FIG. 2 , the disc is bonded to a planar vehicle panel surface 40 of the vehicle by a layer 41 of an adhesive material. The layer 41 has an upper surface 42 adhesively bonded to the bottom surface 31 of the disc. The layer 41 has a bottom surface 43 adhesively bonded to an upper surface of the vehicle panel 40 . [0058] In the kit of parts shown in FIG. 4 , the layer 41 is supplied in a condition in which it is covered by a sheet 44 of a non-adhesive plastics material which covers the adhesive surface 43 of the layer 41 and thus prevents inadvertent adhesion to surrounding elements. In operation, the layer 44 is removed and the adhesive layer 41 applied to the vehicle surface to provide an adhesive bonding effect of the male portion 28 to the vehicle surface. [0059] With the male portion so bonded in place, the fabric cover can be snap-fastened into place simply by pressing the female caps over the respective male portions in their bonded positions, which are arranged in an array matching the array of female caps 17 on the fabric cover 16 . [0060] In a situation where the vehicle surface at the position where the snap fastener is to be located is entirely flat over the area at which it desirable to secure the stud, the male fastening portion 28 functions in the same manner as the rigid-base stud disclosed in Applicant's aforementioned prior art patent by being directly fastened atop the planar vehicle surface. However, while the prior art male portion 28 required a separate flexible piece in order to allow the male portion to be adhesively secured to a non-planar surface that is curved or features multiple planar sections interconnecting at and diverging away from bends or corners in the surface, the flexible disc-shaped base 30 of male fastening portion 28 of the present invention allows direct adhesion to such non-planar surfaces without requiring an additional piece. [0061] FIG. 3 illustrates this added functionality. [0062] FIG. 3A shows the male portion 28 adhered to a three section surface 40 ′ in which three flat, but not coplanar, sections collectively make up the area at which it is desirable to secure a male fastening portion 28 . With reference to FIG. 4 , a top surface of the flexible disc-shaped base 30 of the male fastener portion 28 features a plurality of parallel grooves 30 a recessed therein. The illustrated embodiment features four such parallel grooves, two on each side of the projecting portion 32 projecting upward from this top surface of the disc 30 . Each linearly extending groove travels fully across the disc along a. respective chord of the disc's circular shape, therefore extending fully to the perimeter of the disc at each end of the groove to open to the disc's outer periphery. As best seen in FIGS. 2 and 3 , the top surface of the illustrated disc 30 has a slight linear slope toward the bottom surface of the disc in each radial direction extending outward from the disc's center positioned coaxially beneath the projecting portion 32 . With the bottom surface of the disc 30 being planar when the disc is seated flat on a horizontal surface, the slight slope of the top surface of the disc means that the thickness of the disc 30 tapers slightly moving radially outward toward its peripheral edge. The thinner nature of the disc 30 closer to its outer edge means that the disc is more flexible further away from the projecting portion 32 . [0063] FIG. 3A demonstrates that in order for the flexible disc 30 to best conform to a bent vehicle surface to which it is adhesively secured, one of the grooves 30 a in the disc 30 can be placed to overlie a linear bend line in the surface 40 ′ so that the disc 30 bends along that groove 30 a in order to change direction at the same angle as the bend in the surface 40 ′, thereby providing the best possible conformance between the adhesive-carrying bottom surface of the disc 30 and the relatively sloped sections of the surface. The particular configuration of the surface to which the male piece 28 of the fastener is secured in FIG. 3A , with a central horizontal section and two obliquely inclined sections sloping respectively upward and downward from the central section on opposite sides thereof, is illustrated not to represent a particular vehicle surface for which the fastener is intended for use, but rather to illustrate that the outer portions of the disc defining the peripheral edge thereof can be bent upward or downward relative to the central portion of the disc disposed to the inside of the grooves. Accordingly, the bend lines provided in the disc 30 by the grooves 30 a give the male piece 28 the flexibility to adapt to a number of different possible surface configurations in which it may be desirable to use a fastener of the present invention. Providing more than one groove 30 a on each side of the projecting portion 32 also helps by providing multiple fold or bend axes on each side whereby placement of a different groove 30 a over a particular surface bend allows control over how much of the disc 30 rests on each of the two surface sections joining at that bend to allow the user to select a best one of the possible positions for the application. While the disc 30 of FIG. 3A is positioned on surface sections with rather minor relative slopes between them, it may be able to bend through ninety degrees, for example allowing the piece to be installed in a recessed cavity or elevated position while still using the full bonding surface area provided by the disc by folding upward or downward at the outer grooves to position opposing outer regions of the disc along side walls of the recess or wall profile. [0064] FIG. 3B shows the male piece 28 adhered to a curved surface 40 ″, illustrating that it is not limited to use on an entirely planar surface area ( FIG. 2 ) or adjacently connected but non-parallel surface areas ( FIG. 3A ). With the male fastener piece 28 oriented to lay the grooves 30 a in the disc 30 parallel to a linear axis L about which the surface 40 ″ curves, the bend lines provided by the reduced-thickness grooved portions of the disc 30 aid in the curved bending of the disc 30 abut the axis to better conform to the surface curvature. [0065] The flexibility of the disc 32 for deforming the bottom surface thereof to conform to the recipient surface to which it is adhesively secured is further enhanced by the illustrated configuration of the projecting portion 32 as a hollow structure with cylindrical wall sections of varying diameter that increases moving away from the disc 30 . The projecting portion has a lower cylindrical section 32 a at which the integral connection to the disc 30 is formed, and an upper cylindrical section 32 b disposed atop the lower section with a larger outer diameter than the lower section and larger inner diameter of the lower section. The change in diameter moving along the projection portion 32 is stepwise in nature, with the projection portion extending outward in a radial plane normal to its longitudinal axis at the integral joining of the two sections. The wall thickness over the full height of the projecting portion is substantially uniform, and so the increase in diameter not only applies to the outer diameters moving from the lower section to the upper section, but also to the inner diameters. The hollow interior of the stud defined by the projecting portion 32 may thus be considered as a larger diameter upper chamber, and a smaller diameter lower chamber open thereto immediately therebeneath. The engagement rim 33 of the stud is integrally defined with the periphery of the larger diameter upper section 32 b at the upper extent thereof. Accordingly, moving downward from the distal end of the projecting portion 32 opposite the disc 30 , the projecting portion decreases twice in outer diameter: once from the rim 33 to the outer peripheral surface of the remainder of the upper section 32 b, and again from the upper section 32 b to the lower section 32 a therebeneath. [0066] The hollow structure of the stud provides an interior space capable of accommodating any feature that may be disposed in or project from the female recess 18 of a female cap member 17 to be engaged on the stud. For example, with reference to FIG. 2 , if the cap member 17 was instead riveted to the flexible cover sheet 16 , a portion of the completed rivet would depend into the female recess 18 , and thus require a hollow space in the stud to accommodate it. The hollow stud structure thus allows it to be used with different types of female snap elements. Having the stud hollow over most of its height, but yet closed at the bottom by a circular central portion of the disc 30 disposed beneath the stud's hollow interior balances the maximization of the hollow interior depth to accommodate projecting features of female cap members with maximization of the available bottom surface area of the disc 30 for adhesion to the vehicle surface to increase the bond strength of the male piece 28 to the vehicle. Positioning of the grooves 30 a in the top of the disc also contributes to the use of the entire bottom surface of the disc for adhesion purposes to maximize the overall adhesive bonding strength. [0067] The slight increase in disc thickness from the outer edges of the disc 30 to the central portion thereof helps increase the rigidity with which the integral engagement rim 32 on the projecting portion is carried on the central portion on the disc 30 to help substantially retain the shape and position of the rim 33 during pushing of a female cap onto the stud to effect the snap fit, while the full-depth hollow interior of the stud reaching fully down to where the disc joins the lower cylindrical section balances with this so as to retain some flexibility in the central portion of the disc 30 disposed directly beneath the stud. While some or all of the stud interior could instead be filled with material, this would not only be detrimental the suitability of the male piece 28 as a universal snap fastener stud cooperable with female cap types with or without projecting features, but also may result in a reduction of the deformability of the bottom surface of the disc 30 directly beneath the projecting portion 32 , thereby reducing the overall effective flexibility of the disc and its degree of shape conforming capability. The illustrated positioning of an inner one of the grooves 30 a on each side of the projecting portion at a position directly beneath the larger diameter upper section thereof, nearly immediately adjacent the integral joining of the disc and projecting portion, increases the flexibility of the disc 30 near the projecting portion across the bend line or axis defined by this linear groove. [0068] The multi-step reduction of the projecting portion 32 moving therealong toward the disc 30 also helps maximize the flexibility of the disc 30 to better ensure compliance to the shape of an intended recipient surface of a vehicle. If the larger diameter of the illustrated upper section 32 b was alternatively applied fully from the engagement rim 33 to the base disc 30 , the annular outer portion of the disc 30 left outward from the integral connection to the projecting portion 32 would be smaller. As the flexibility of the disc 30 increases moving away from the central projecting portion 32 , the amount by which the outer periphery of the disc can flex upward and downward would accordingly be reduced, again reducing the conforming abilities of the disc 30 and thus reducing the number of differently shaped vehicle surfaces the male piece 28 could be secured to with maximum adhesion surface area between the disc and vehicle surface. [0069] The use of the illustrated circular disc shape of the flexible base 30 , or an oval-shaped disc, lacks corners so as to avoid the presence of points or sharp corners which, when the base is attached to the vehicle, can be picked or abraded and thus increase the possibility of the sheet being removed from its adhesive position on the vehicle surface. The adhesive layer, as may be provided by double sided tape applied to the male part, is coextensive with the undersurface of the flexible disc itself. [0070] The fasteners described above are not limited to the illustrate use for a tonneau cover, and for example may be used to mount a grill cover in the position described in Applicant's aforementioned prior patent or for other vehicular or non-vehicular applications. The one-piece male or stud element described herein can be molded from Lexan™ polycarbonate material, but it may be possible to use other suitable materials to produce the described the one-piece configuration with a flexible base and relatively more rigid stud projection carried thereon. An additional drawing sheet is enclosed herewith as an appendix, and presents exemplary dimensions of a particular embodiment, which are not intended as limiting to the scope of the present invention. [0071] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
A fastening element features a female cap member and a unitary stud body defining a flexible base portion and a projecting portion integral therewith. A peripheral rim of the projecting portion stands upwardly from the base portion and is engageable into the female cap member as a snap fastener, and a bottom surface of the flexible base is deformable relative to the projecting portion. A layer of adhesive is sandwiched between the bottom surface of the flexible base portion and a removable covering layer for adhering to a surface on which stud is to be mounted. The one piece stud body can be produced efficiently while its flexible base is adaptable to mount on any of a variety of differently shaped surfaces, such as non-planar surfaces of a vehicle body to allow selective securing of a fabric cover on the vehicle via a corresponding female cap secured on the cover.
1
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to heat exchange devices for use with air conditioning devices and the like and especially for heat exchange structure which will greatly increase the overall efficiency of such process. 2. Description of the Prior Art A common problem with known type heat exchange devices used with air conditioners and especially of the automotive type, is that an efficient exchange between the gas/liquid flowing in the air conditioning system with the ambient air circulating over the heat exchange surfaces leaves quite a bit to be desired. The overall cooling in the automobile with which such an air conditioner is used depends greatly upon the efficiency of the condensing coil as well as the evaporating coil. Any improvement in either or both of these heat exchange coils will greatly increase the overall efficiency of the system. Another problem with known type heat exchange systems as used with automotive air conditioners and the like is that the construction expense and material expense are quite great. Anything that can be done to decrease the cost of the cooling and condensing units will be of great benefit. SUMMARY OF THE INVENTION An object of the present invention is to provide a heat exchange structure for use with automotive-type air conditioner systems and the like which will increase the overall efficiency of such system. Another object of the present invention is to provide a heat exchange system which will be more readily manufactured with less expense than known type devices. A further object of this invention is to provide a heat exchange structure which may be used for either the condensing coil unit of an air conditioning system, or the cooling coil unit of said system, or both if desired. A still further object of this invention is to provide a heat exchange structure which includes a basic plate member for mounting upon appropriate associated structure, tubular flow structure firmly attached to said mounting plate in good heat flow relationship thereto and projecting pin members arranged in various embodiments, and alternately in single or double rows with the flow tubing structure in order to greatly increase the overall efficiency of the device. A further object is to provide a heat exchange structure which is more easily manufactured at less cost and more quickly than conventional type exchange structures. The heat exchange structure and the various embodiments thereof of this invention consists basically of a primary plate member or members supporting securely attached and in good heat flow relationship thereto flow structure for conducting the gas/liquid medium as used in conventional air conditioners and especially as used in automotive type air conditioners. Projecting from the support plate member are pins securely attached thereto for greatly increasing the surface area over which the surrounding air flows, either by convection or preferably by forced blower means, in order to greatly increase the overall efficiency of the heat exchange process. The flow tubing is arranged to alternately reverse the flow path of the medium being conducted thereby and also alternately spaced with the projecting pins arranged in single or double rows therebetween. The pins may be supported through punched or drilled apertures in the plate member and then secured by brazing, soldering, or other deposition of metal material to securely attach and hold the projecting pins within and on the plate member. Another embodiment utilizes the primary plate together with a secondary plate to form a flow path therebetween for the gas/liquid medium. In this embodiment the flow tubes are eliminated and the plate members themselves form the conducting flow channel for such refrigerant medium. These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partly in cross section, of an automotive type air conditioner system using the heat exchange device of this invention. FIG. 2 is a view, in part, of a heat exchange device as used in FIG. 1. FIG. 3 is an end view, in part, of another type of heat exchange device as used in FIG. 1. FIG. 4 is a side cross-sectional view taken generally along line 4--4 of FIG. 3. FIG. 5 is an enlarged detail of one of the heat exchange pins as mounted and secured in one of the plate members. FIG. 6 is a modified embodiment of the plate members for providing an integral gas/liquid flow channel. FIG. 7 is another embodiment as arranged to provide for an automobile type radiator cooling coil. FIG. 8 is a side cross-sectional view taken generally along line 8--8 of FIG. 7. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, reference numeral 10 indicates in general, the arrangement of two heat exchange devices as used with a automotive type air conditioning system. The top of the auto air conditioner is indicated by reference numeral 12 with two end portions 14, 14' and a bottom structure 13. Air flow grilles 15, 15' are provided in each of the ends with a cooling air container 16 being provided in one-half of the overall housing and a condenser unit 18 being provided in the other. A partition 20 of insulating material separates the two portions of the air conditioner system. A conventional type auto or house refrigeration compressor 22 is provided on or within the condenser portion of the overall air conditioner. This structure is basically conventional and will not be described in greater detail. Blower units 24 and 24' provide a forced air flow over the respective cooling and condenser units. A water and condensate collecting pan 26 is provided mounted upon appropriate supports 28 from the bottom structure 13. This collection pan may be connected to discharge tubing for feeding any collected water outside of the overall housing. A support structure 29 also is provided and associated with the housing for the condenser structure 18. An air inlet grille 27 is also provided for the cooling unit while an air intake flap 31, shown in part and which may be adjustable, is provided for the condenser unit. Mounted upon the cooling end of the air conditioner is an adjustable thermostat 21, having a knob 23 and associated wiring 25 for connection to the electrical wiring of the air conditioner. As is conventional with air conditioner units the compressor 22 compresses the refrigerant within the system into normally liquid form which passes through the heat exchange unit 30 within the condenser portion 18 of the system. At this point, forced air from the blower 24' which enters through the flap 31 at the bottom of the air conditioner housing upwardly into the inlet A of the blower for pressure exhaust at B and for flow over the heat exchanger plate 32 to the top thereof at gap C, and then downwardly and outwardly over projecting pins 36 for exhaustion through the grille 15. The liquid refrigerant is the passed through an expansion valve or other conventional type cooling means into the cooling unit 30' at the right of the view of FIG. 1. Input air is drawn in through the grille 27 and into the blower 24 at input A' for forced discharge at B' and upward flow over the backside of plate 32' through the gap C' and then downwardly and outwardly past the projections 36' for discharge out grille 15'. The expanding refrigerant in the heat exchanger 30' within cooling portion 16 greatly cools the air being forced thereover to provide the appropriate cooling at the discharge 15' of the air conditioner. While the refrigerant flow tubing 34, 34' in FIG. 1 is shown as transversing back and forth in a horizontal direction, the units will work equally as well with the tubing transversing vertically. This manner of construction is best seen in the embodiment of FIG. 2. In this embodiment, the flow tubing 34 is appropriately connected at respective ends thereof by the continuing portions of the tubing 35 so that the tubing traverses the plate 32 as seen. The tubing is securely fastened to the plate member 32 by means of soldering, brazing, or other type of metal welding procedures. Appropriate outer flanges 33 may be provided at the edges of the plate member 32 for strength and rigidity. In order to increase the overall efficiency of the heat exchange between the refrigerant flowing through the tubing and the air passing over the combined tubing and plate, projecting pins 36 are provided. These projecting pins as shown in FIG. 2 may be arranged in two rows alternating with the refrigerant flow tubing. This arrangement has been discovered to greatly increase the heat transfer relationship of the structure. In FIG. 3, the flow tubing is arranged alternately and traversely in a horizontal direction with flow tubing 34' connected at the respective ends thereof with continuous flow tubing 35'. In this embodiment single rows of pins 36' alternate with the flow tubing. This embodiment also may be seen in cross section in FIG. 4 wherein the length of the pins 36' with respect to the diameter and size of the refrigerant flow tubing 34' may be compared. As indicated generally by reference numeral 40 in FIG. 4, the pins are secured to the plate member 32' as best seen in the enlarged view of FIG. 5. Here the plate 32 is shown with a single perforation or aperture provided therein. This aperture 41 may be appropriately punched, drilled, or otherwise provided in the plate. Normally, if a punching process is used a flanged edge 42 will surround the hole in the direction opposite from which the punch was made. A punching operation is a relatively quick and inexpensive method of providing the needed number of holes in the plates 32. Pins 36 having heads 37 thereon are then placed through the apertures 41 and then metal solder or brazing material 44 completely covers the head and surrounds the aperture to secure the pins within the holes. It should be noted that the diameter or outer circumference of pins 36 preferably are just slightly larger than the apertures 41 so that said pins must be force fitted into the respective holes. This in addition to the weld or solder material 44 functions to positively hold said pins in good heat exchange relationship with the plate 32. While the embodiment of FIG. 2 shows alternately spaced flow tube paths alternately with double rows of heat exchange pins, and the embodiments of FIGS. 3 and 4 show single rows of spaced heat exchange pins between the traversing flow tubing, the embodiment of FIG. 6 eliminates the traversing alternating tubes 34, 34' and replaces them with a second plate structure for containing the refrigerant flow. In this arrangement, the primary plate 52 supports and contains the spaced projecting pins 36 as described for the previous embodiments. However, in addition to this plate another plate 53 having apertures 51 therein is attached at the edges 50 to the first plate 52. The spacing between the plates 52 and 53 provides the refrigerant flow channel in place of the tubing 34, 34'. Inwardly flange portions 56 on the plate 52 meet and complement inwardly flange portions 57 on the plate 53, and are appropriately welded or otherwise joined together along line 50 at the junction point therebetween. An input tube 48 and an exhaust tube 49 are also provided in apertures in one of flanges 56, or 57 of the respective plates. Obviously, all the connections of the tubing projecting pins, apertures, flared junction joints, etc. are securely brazed or welded to form fluid and air tight junctions. In this embodiment, the refrigerant flow will directly contact the portions 36a of the heat transfer pins contained within the plates 52 and 53 while the outer portions of the pins 36b will conduct the heat to the air flowing thereover. Thus, one can readily visualize how the overall efficiency of this heat exchange device will be greatly increased by this method of arrangement and construction. FIGS. 7 and 8 show another embodiment of the heat exchange device as used for the condenser unit normally mounted adjacent an automotive radiator in an automobile type air conditioning structure. This embodiment is quite similar to that of FIGS. 3 and 4, but has a plurality of plate members 62 instead of a single plate member 32 as in the embodiment of FIGS. 3 and 4. These plurality of plate members 62 are mounted upon end support structure 64 which in turn may be appropriately secured adjacent the radiator of an automobile. Pins 36' are provided on either side of the flow tubing 34' for the refrigerant. Again, all the component parts are secured together by soldering, brazing, welding or the like. From the above description, one can readily visualize how the improved heat exchanger structure as disclosed herein will greatly increase the efficiency of same and also increase the overall efficiency of the entire air conditioner system. The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
A heat exchange device for air conditioners and the like comprising a primary body member of sheet plate material having tubular flow conduit fastened thereto for receiving and containing the flow of fluid such as the liquid/gas used with air conditioners and the like. Projecting pins securely attached to the plate member or members in single or double rows alternately with the tubing material provide the heat exchange improvement. Several different embodiments of the tubing and rows of projecting pins are provided for various type of applications. Another embodiment replaces the tubular flow conduit with a second plate member with the refrigerant flow being between the two plate members.
5
BACKGROUND OF THE INVENTION [0001] The present invention relates to printed matter, and more particularly to books and bookselling (Class 283/63.1). [0002] Books are publicized to readers in a variety of ways, including book reviews, author interviews on radio and television, author readings at bookstores, advertising, etc. However, the most effective method of publicizing books remains word of mouth. [0003] The Internet bookseller Amazon has pioneered new ways to publicize books. Most successful is their “Associates” program (http://www.amazon.com/associates). 900,000 Amazon Associates recommend their favorite books on their websites. In return, Amazon gives Associates a 5% sales commission. This helps Amazon sell millions of books, while providing income to Associates. Associates include individuals as well as institutions such as libraries and public radio stations. Amazon's computer technology is new but beneath it all is old-fashioned “word of mouth.” [0004] Amazon Associates sell millions of books each year, but far more books are sold when readers simply tell their friends about a book they like. Publishers may be grateful to such readers, and might be willing to pay such readers a sales commission, but publishers have no way to identify such readers. A need exists for a simple, easy to use method and system that encourages readers to recommend books to their friends, and enables publishers to identify and remunerate such readers. [0005] Publishers also give away dozens, often hundreds of free books for promotional purposes. Publishers stamp such books “Review Copy-Not For Sale” or a similar message. Scrupulous used booksellers, including Amazon, forbid the sale of such promotional copies. Many newspapers and magazines have ethics policies forbidding employees from selling promotional items. However, promotional copies inevitably turn up for sale by used booksellers. Publishers would benefit from a way to trace back such illicit copies to identify the book reviewer or other person who sold the book to the used bookseller. BRIEF SUMMARY OF THE INVENTION [0006] Generally speaking, in accordance with the Invention, a combination of cards bound into books and a computer database system to track such cards is provided. [0007] Accordingly, it is an object of the Invention to encourage readers to recommend favorite books to friends and acquaintances. [0008] It is another object of the Invention to enable publishers to remunerate readers who recommend books to friends and acquaintances. [0009] It is another object of the Invention to enable publishers to identify readers who recommend books to friends and acquaintances, and use this information to improve marketing programs. [0010] Still other objects and advantages of the invention will, in part, be obvious and will, in part, be apparent from the specification. [0011] The invention accordingly comprises the features of construction, combinations of elements and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 shows the front of a card that enables readers to register their books and the back of the cards a reader gives to friends. [0013] FIG. 2 shows the back of a card that enables readers to register their books and the front of the cards a reader gives to friends. [0014] FIG. 3 shows the front of a card that enables readers to recommend a book to their friends, and encourage the friends to order the book from a bookstore. [0015] FIG. 4 shows the back of a card that enables readers to recommend a book to their friends, and encourage the friends to order the book from a bookstore. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] In the first configuration of the Invention, two postcard-sized (six inches by four inches) cards are bound into a book. The cards are most easily bound into the book between the back cover and text pages, or between the front cover and the text pages. [0017] The first card explains to the reader that he or she will receive a sales commission (typically 15%) for recommending the book to his or her friends. This card also explains that the friends will receive a discount (typically $5) when ordering the book from the publisher (or from a fulfillment house representing the publisher). [0018] The first card also suggests that reader can specify a charity that the publisher will donate the sales commission to, if the reader doesn't wish to receive a sales commission (or if the reader doesn't wish to identify himself or herself to the publisher). [0019] The first card also suggests that the reader can photocopy the second cards as often as he or she wishes, or e-mail the information on the cards to many friends. [0020] The first card has spaces for the reader to fill in his or her name and address. This card also has a space to write the serial number from the second cards. This serial number could be pre-printed on the first card, but this introduces the possibility of mixing up matched first and second cards when binding the books. To eliminate such errors, the serial number is printed only on the second cards, and the reader is expected to copy the serial number from the second cards to the first cards. [0021] The first card also lists a website where the reader can register his or her book electronically, instead of mailing the card. Readers outside the United States may prefer this option, to save paying for postage. [0022] Lastly, the converse side of the first card has the publisher's address and pre-paid postage indicia. This enables the reader to simply drop the card in the mail. The card is perforated for easy removal from the book. [0023] The second cards are actually four business-sized (three inches by two inches) cards, perforated for easy separation. The second cards say “I recommend” and the title of the book. The second cards are intended for the reader to give to friends and acquaintances. The cards inform the friends that they will receive a discount (typically $5) when ordering the book from the publisher. The cards then provide the publisher's telephone number and website for ordering. [0024] The second cards also have a serial number. Direct mailing services can easily print serial numbers using inkjet printers. The same serial number is printed on all four business-sized cards. [0025] Lastly, the converse side of the second card shows a small version of the book's cover. [0026] After the readers mail their cards to the publisher, the publisher enters the data into a relational database. The database has fields for each reader's name, address, telephone number, and e-mail address. Other fields store the book title (or ISBN number) and the serial number of the reader's book. [0027] A second, related database stores the invoices for books sold. This database has similar fields for the name, address, etc. of the person buying the book. In addition, an optional field stores the serial number used to order the book (and receive a discount). This is the serial number of the book owned by the person who recommended the book. [0028] The second database can also have a field for the serial number of the book being shipped out. This is less important and introduces the possibility of error when matching invoices and books. To reduce such errors, it's better not record the serial of the book on the invoice. [0029] At certain intervals (e.g., monthly) the publisher runs several reports from the two related databases. The first report lists the number of books shipped that were ordered using the same serial number. This report enables the publisher to pay readers who recommend a book to their friends. [0030] A second report ranks the readers in order of number of referral sales. The publisher may then contact the top readers and ask what they did to recommend the book. E.g., the publisher may discover that a hair stylist recommended a book to fifty clients. The publisher then markets the book to other hair stylists. Or the publisher may see that the top sellers are in a certain city or state, and plan an author book tour in that region. [0031] A publisher may also record the serial numbers of books sent out. E.g., a publisher is considering sending free copies of a book to psychologists. The publisher has a choice of buying mailing lists from several psychology associations and journals. Each mailing has thousands of addresses. The publisher “tests the waters” by sending out one hundred copies to a sample of each database. The publisher records the serial numbers of each set of books, and then later runs a database report to see which mailing list produced the most referral sales. [0032] A publisher might also record the serial numbers of promotional books mailed out, e.g., to book reviewers. When used books stamped “Review Copy—Not For Sale” appear in bookstores, the publisher checks the serial numbers on the list and contacts the recipient to inquire as to how a promotional copy got into a used bookstore. For example, I traced a promotional copy of a book sold on Amazon to a magazine publisher. The magazine publisher assured me that their book reviewers never sold promotional copies and that this copy must have been taken from their dumpster by a scavenger. The magazine publisher profusely apologized and offered to promote the book on their website, even though their reviewers had chosen not to review the book. [0033] This configuration of the Invention could also be used to promote compact disk (CD) music recordings and digital video disk (DVD) recordings of movies. [0034] In the second configuration of the Invention, a single card (approximately six inches by four inches) is bound into a book, usually between the back cover and text pages. This card is divided into four small cards (approximately three inches by two inches), perforated for easy separation. [0035] These cards say “I recommend” and the title of the book. The cards are intended for the reader to give to friends and acquaintances. The cards then say “Available at” and have a blank space for bookstores to rubberstamp their addresses. [0036] The converse side of these cards show a small version of the book's cover. [0037] No computer database is necessary for the second configuration of the Invention. [0038] The new technology that makes this Invention useful isn't fully described in the above paragraphs. The real technological advances are in printing, such as Xerox Docutech “print on demand” systems that enables small publishers to print small quantities of books easily and cheaply; and the Internet (including Amazon), which enables small publishers to promote specialized books to niche markets. [0039] These new technologies have engendered many small publishing companies. According to Bowker's Books in Print, there are 73,000 publishers in the United States. 11,000 new publishing companies start each year. This figure grows 30% annually. [0040] At the same time, the percentage of books sold in bookstores is dropping, and is now well below 50%. [0041] Big, traditional publishers would not find this Invention useful. They sell books through bookstores. Their books are stocked in all mainstream bookstores. They don't want to sell books via readers calling a fulfillment house, as this would anger bookstores. Readers can recommend a traditional publisher's book without saying where to buy the book, because the book will be available in almost any bookstore. [0042] In contrast, small publishers can't get their books into bookstores. Small publishers prefer to sell directly to readers, skipping the distributors, wholesalers, jobbers, retailers, etc. that take most of the money readers pay for books. Small publishers usually publish niche books, where “word of mouth” marketing is most effective. This Invention is most useful for small, niche publishers; who use novel technologies such as “print on demand” and Internet marketing; and this Invention is not obvious to anyone familiar with how traditional book marketing. [0043] Thus, by utilizing the above construction, a combination of cards bound into books and a computer database for improving “word of mouth” promotion of books is realized. [0044] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and 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. [0045] It will also be understood that the following claims are intended to cover all of the generic and specific features of the invention, herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
A set of postcards bound into book (or packaged with a CD or DVD) encouraging a reader to recommend the book to friends, and enabling the reader to register the book with publisher, and a computer database system for the publisher to reward and/or remunerate the reader for recommending the book to friends, and to enable the publisher to evaluate the effectiveness of marketing campaigns.
6
REFERENCE TO RELATED APPLICATION This application is a continuation of application Ser. No. 710,612, which was filed Aug. 2, 1976, and is now abandoned. BACKGROUND OF THE INVENTION Webs of microfibers as taught in the prior art have significantly limited utility utility as thermal insulation. This is true despite the fact that previous investigators of microfibers have almost routinely included thermal insulation in their lists of potential uses for the fibers. See several patents dealing with blown microfibers, including Francis, U.S. Pat. No. 2,464,301; Ladisch, U.S. Pat. No. 2,571,457; Watson, U.S. Pat. No. 2,988,469; and Buntin et al, U.S. Pat. No. 3,849,241 (blown microfibers are very fine, discontinuous fibers prepared by extruding liquified fiber-forming material through orifices in a die into a high-velocity gaseous stream, where the extruded material is first attenuated by the gaseous stream and then solidifies as a mass of the fibers); or see Vinicki, U.S. Pat. No. 3,388,194, which describes microfibers formed by a centrifugal spinning operation. While these previous workers did not report thermal insulation values for a web of microfibers, or give any indication of having measured such values, they appear to have automatically considered that a new fibrous web should be useful as thermal insulation. The limited value of existing microfiber webs as thermal insulation is true despite another fact, which is not set forth in any known prior literature, namely that microfiber webs provide unique insulating values. For example, a one-centimeter-thick web of polypropylene blown microfibers will give 1.8 clo of thermal resistance, in contrast to the about 0.9 exhibited by a 1-centimeter-thick web of commerical polyester staple fibers. 1 (Footnotes and methods of measurement are at the end of the specification). The reason why existing microfiber webs have only limited value as thermal insulation is that, at least after these microfiber webs have undergone a normal compression history, they are heavier than alternative types of fibrous insulation. This heaviness is an inherent consequence of the very nature of microfibers; their very fine size and comformability causes the microfibers to come together as a dense, fine-pored web. As an illustration, a one-centimeter-thick web of blown microfibers is about five times as heavy as a one-centimeter-thick web of commercial polyester staple fibers. Even if a blown microfiber web only half as thick as a web of polyester staple fibers is used (so as to provide roughly equivalent thermal insulation resistance), the blown microfiber web will still be about two-and-one-half times as heavy as the polyester staple fiber web. When weight is only of secondary importance (as in glove or boot insulation, for example), thin, dense, blown microfiber webs can be quite useful. But when weight is a more primary consideration, as in such insulated articles as coats, snowmobile suits, sleeping bags, etc., existing microfiber webs will be passed by. Since the latter kinds of uses are major ones, the foreclosing of microfibers from such uses is a severe limitation on their utility in the insulation field. SUMMARY OF THE INVENTION The present invention provides a new fibrous web which has a moderate weight comparable to or lower than the weight of alternative forms of fibrous insulation, but which nevertheless exhibits the same order of high thermal resistance per unit of thickness that characterizes existing microfiber webs. This new web incorporates microfibers (generally less than 10 micrometers in diameter), but only as one component fiber in the web. In addition, a web of the invention includes bulking fibers, i.e. crimped, generally larger-diameter fibers, which are randomly and thoroughly intermixed and intertangled with the microfibers and account for at least 10 weight-percent of the fibers in the web. The crimped bulking fibers function as separators within the web, separating the microfibers to produce a lofty resilient web capable of filling a much larger volume than a conventional microfiber web. Correspondingly, the density of the composite web is greatly reduced from that of a conventional microfiber web. Yet, despite the dilution of the web with bulking fibers, and the loosening or opening of the web caused by those fibers, the thermal resistance per unit of thickness remains the same or is only moderately reduced in comparison to an all-microfiber web. Since a composite web of the invention is thicker than an all-microfiber web that includes the same weight of microfibers, the total thermal resistance of the web from face to face is greater than that of the all-microfiber web. And per unit of weight, the composite web provides much more insulation than an all-microfiber web. The latter advantage gives rise to a concept of "thermal insulating efficiency by weight", which is equal to the thermal resistance for a sample in clo per unit of thickness divided by the density of the web in units of weight per unit of volume. Webs of the invention have higher values of thermal insulating efficiency by weight than any other known fibrous web. The reason for the high values of thermal resistance per unit of thickness or high values of thermal insulating efficiency per unit of weight exhibited by composite webs of the invention is not fully understood. The microfibers are spaced apart by the presence of the bulking fibers, which increases the size of the pores within the web; if fine pore structure contributes to the good insulation value of conventional microfiber webs, it does not determine the insulation value of a composite web of the invention. The most likely explanation for the high insulating values of a web of the invention, in our view, is that a thin layer of air contacting a fiber or other surface is held by that surface against movement. Since the surface area of microfibers is greater than for larger fibers such as polyester staple fibers, more air is held in place by the microfibers, which results in a reduced transfer of heat within a web containing microfibers. Although the percentage of microfibers in a web of this invention is less than that in an all-microfiber web, sufficient microfibers are apparently retained to make the thermal resistance per unit of thickness of the web comparable to that of an all-microfiber web. Also, when the microfibers are opened up or spaced apart by the presence of bulking fibers in a web of the invention, the surface area of the microfibers is more effectively used, making it possible to hold more air in place and even further reduce the transfer of heat. Whatever the explanation, the invention makes a major advance in the use of microfibers. A practical effect of the change made by the present invention can be shown with this illustration: A representative composite web of the invention one-half as thick and lighter in weight than the widely commercialized webs of polyester staple fibers will produce the same thermal resistance as the polyester web. Thus, a jacket insulated with a web of the invention may be thinner and lighter in weight than a jacket insulated with a polyester staple fiber web and yet be just as warm. The lesser bulk and lighter weight are significant effects, and mean that for the first time microfibers offer a significant advantage to widespread areas of the insulation field. Webs of the invention are useful for other purposes also, especially where the presence of microfibers, with the special properties provided by them, in combination with loft and moderate density offers a special advantage. Webs of the invention are not the first to mix microfibers with other fibers. The Francis and Watson patents noted above teach the mixing of tacky blown microfibers with preformed fibers to form a bonded web. Perry, U.S. Pat. No. 3,016,599 is directed to a method of uniformly mixing microfibers and staple fibers to form a composite web. And Wyly et al, U.S. Pat. No. 3,532,800 teaches paper-type products useful as electrical insulation for cables made by blending microfibers with staple fibers. But none of these prior art teachings suggests the lofty resilient microfiber-based products of the present invention or the unique properties provided by such products. Loft and resilience are provided in webs of the invention by the crimped bulking fibers, thoroughly separated and mixed with the microfibers; and none of the prior-art references teaches such a blend of fibers. Use of crimped fibers in the processes of the references would require mechanical force to separate the fibers; lacking such apparatus, the prior-art processes would produce webs with isolated concentrations or clumps of crimped fibers, through which heat energy would be more rapidly transferred and which would not contribute to the lofty microfiber-based mixture that provides special properties in webs of the invention. Although the Watson and Francis patents noted above list wool fibers, which are commonly used in a crimped form, as potentially useful in their processes, it seems clear that they never prepared webs using such fibers; in any event, these references do not contemplate or suggest a web of the present invention, with its unique lofty structure obtained by a thorough blend of microfibers and crimped bulking fibers; do not teach apparatus or process conditions for preparing such a web; and do not recognize the useful properties provided by the unique structure of a web of the invention. Loft as well as resilient compressibility and conformability, are also reduced by the bonded nature of the webs taught in prior art such as Francis and Watson. Such bonding, i.e. fiber-to-fiber bonding resulting from collection of fibers while the microfibers are tacky, is especially undesirable in webs of the invention to be used as thermal insulation for garments, sleeping bags, etc. Unbonded fiber structures of the invention, which are greatly preferred, offer excellent conformability, drape, hand and feel, which give them further appeal in the thermal insulating field. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of illustrative apparatus for preparing webs of the invention; and FIG. 2 is side elevation view of representative crimped bulking fibers useful in webs of the invention. DETAILED DESCRIPTION FIG. 1 of the drawing shows one arrangement of apparatus useful to prepare a web of the invention. This apparatus prepares webs with melt-blown microfibers (prepared by extruding molten fiber-forming material and which are preferred in many webs of the invention), but solution-blown and other types of microfibers may also be used. The microfiber-blowing portion of the illustrated apparatus can be a conventional structure as taught, for example, in Wente, Van A. "Superfine Thermoplastic Fibers," in Industrial Engineering Chemistry, Vol. 48, pages 1342 et seq (1956), or in Report No. 4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Superfine Organic Fibers" by Wente, V. An.; Boone, C. D.; and Fluharty, E. L. Such as structure includes a die 10 which has an extrusion chamber 11 through which liquified fiber-forming material is advanced; die orifices 12 arranged in line across the forward end of the die and through which the fiber-forming material is extruded; and cooperating gas orifices 13 through which a gas, typically heated air, is forced at very high velocity. The high-velocity gaseous stream draws out and attenuates the extruded fiber-forming material, whereupon the fiber-forming material solidifies as microfibers during travel to a collector 14. The collector 14 is typically a finely perforated screen, which in this case is in the form of a closed-loop belt, but which can take alternative forms, such as a flat screen or a drum or cylinder. Gas-withdrawal apparatus may be positioned behind the screen to assist in deposition of fibers and removal of gas. The crimped bulking fibers are introduced into the stream of blown microfibers in the illustrative apparatus shown in FIG. 1 through use of a lickerin roll 16 disposed above the microfiber-blowing apparatus. A web 17 of bulking fibers, typically a loose, nonwoven web such as prepared on a garnet machine or "Rando-Webber", is propelled along a table 16 under a drive roll 19 where the leading edge engages against the lickerin roll 16. The lickerin roll turns in the direction of the arrow and picks off fibers from the leading edge of the web 17, separating the fibers from one another. The picked fibers are conveyed in an air stream through an inclined trough or duct 20 and into the stream of blown microfibers where they become mixed with the blown microfibers. The air stream is generated inherently by rotation of the lickerin roll, or that air stream may be augmented by use of an auxilliary fan or blower operating through a duct 21 as known in the art. The mixed stream of microfibers and bulking fibers then continues to the collector 14 where the fibers form a web 22 of randomly intermixed and intertangled fibers. Under close examination, the microfibers and crimped bulking fibers are found to be thoroughly mixed; for example, the web is free of clumps of crimped fibers, i.e. collections a centimeter or more in diameter of many crimped fibers, such as would be obtained if a chopped section of multi-ended tow of crimped filament were unseparated or if crimped fibers were balled together prior to introduction into a microfiber stream. The web 22 is peeled off the collector, and typically wound into a storage roll. Subsequently the web may be processed in cutting or handling operations appropriate for microfiber webs. The composite web prepared may consist of a single layer deposited by apparatus as shown, or may be a multi-layer product (in which the layers are typically indistinguishable to at least casual inspection). Such products can be formed either by passing the collected web under mixing and depositing apparatus such as illustrated in FIG. 1 two or more times or by having additional mixing and depositing apparatus disposed along the length of a collecting belt. The insulating quality of microfibers is generally independent of the material from which they are formed, and microfibers useful in the invention may be formed from nearly any fiber-forming material. Representative polymers for forming melt-blown microfibers include polypropylene, polyethylene, polyethylene terephthalate, polyamides, and other polymers as known in the art. Useful polymers for forming microfibers from solution include polyvinyl chloride, acrylics, and acrylic copolymers, polystyrene, and polysulfone. Inorganic materials also form useful microfibers. The finer the microfibers in a web of the invention, the better the thermal resistance. Blown microfibers can conveniently be prepared in diameters smaller than one micrometer. To form useful webs, the aspect ratio (ratio of length to diameter) of the microfibers should approach infinity, though blown microfibers are known to be discontinuous. Crimped fibers, i.e. having a continuous wavy, curly, or jagged character along their length, are available in several different forms for use as the bulking fiber in a web of the invention. Three representative types of known crimped fibers are shown in FIG. 2: FIG. 2 a shows a generally planar, regularly crimped fiber such as prepared by crimping the fibers with a sawtooth gear; FIG. 2 b shows a randomly crimped (random as to the plane in which an undulation occurs and as to the spacing and amplitude of the crimp) such as prepared in a stuffing box; and FIG. 2 c shows a helically crimped fiber such as prepared by the so-called "Agilon" process. Three-dimensional fibers as shown in FIGS. 2 b and 2 c generally encourage greater loftiness in a web of the invention. However, good webs of the invention can be produced from fibers having any of the known types of crimp. The number of crimps i.e. complete waves or cycles as represented by the structure 23 in FIGS. 2 a, b, and c, per unit of length can vary rather widely in bulking fibers useful in the invention. In general the greater the number of crimps per centimeter (measured by placing a sample fiber between two glass plates, counting the number of complete waves or cycles over a 3-centimeter span, and then dividing that number by 3), the greater the loft of the web. However, larger-diameter fibers will produce an equally lofty web with fewer crimps per unit of length than a smaller-diameter fiber. An indication that variation is permissible is provided by the following table, which shows the approximate crimp count we presently prefer for a given diameter fiber. ______________________________________Fiber Size Crimp Count______________________________________(decitex) (crimps/centimeter) 3-20 3-620-40 2-5 40-100 1-3100-400 1-2______________________________________ Processability on a lickerin roll is usually easier with smaller-diameter fibers having higher numbers of crimps per unit of length. Bulking fibers used in the invention will generally average more than about one-half crimp per centimeter, and since the bulking fibers will seldom exceed 40 decitex, we prefer fibers that have a crimp count of at least about 2 crimps per centimeter. Crimped fibers also vary in the amplitude or depth of their crimp. Although amplitude of crimp is difficult to uniformly characterize in numerical values because of the random nature of many fibers, an indication of amplitude is given by percent crimp. The latter quantity is defined as the difference between the uncrimped length of the fiber (measured after fully straightening a sample fiber) and the crimped length (measured by suspending the sample fiber with a weight attached to one end equal to 2 milligrams per decitex of the fiber, which straightens the large-radius bends of the fiber) divided by the crimped length and multiplied by 100. Bulking fibers used in the present invention generally exhibit an average percent crimp of at least about 15 percent, and preferably at least about 25 percent. To minimize processing difficulties on a lickerin roll with fibers as shown in FIGS. 2 a and 2 b the percent crimp is preferably less than about 50 percent; but processing on a lickerin roll of helically crimped fibers as shown in FIG. 2 c is best performed if the percent crimp is greater than 50 percent. The bulking fibers should, as a minimum, have an average length sufficient to include at least one complete crimp and preferably at least three or four crimps. When using equipment such as a lickerin roll, the bulking fibers should average between about 2 and 15 centimeters in length. Preferably, the bulking fibers are less than about 7-10 centimeters in length. Many different materials are useful for forming synthetic crimped bulking fibers, which are preferred; but naturally occuring fibers may also be used. Polyester crimped staple fibers are readily available and provide useful properties. Other useful fibers include acrylics, polyolefins, polyamides, rayons, acetates, etc. Webs of the invention will have the best resistance to compression and the highest thermal insulating efficiency by weight when the bulking fibers are moderately stiff, that is, have a flexural rigidity of 1.5 × 10 -4 gram-square centimeters per tex or more (defined by W. E. Morton and J. W. S. Hearle, Physical Properties of Textile Fibers, Butterworth, London, 1962, p. 380-383). More preferably the bulking fibers have a flexural rigidity of at least 3.5 × 10 -4 gram-square centimeters per tex. Webs of the invention may include more than one variety of bulking fiber, as well as more than one variety of microfiber. The finer the staple fibers, the greater the insulating efficiency of a composite web, but the web will generally be more easily compressed when the staple fibers are of a low denier. Most often, the bulking fibers will have sizes of at least 3 decitex and preferably at least 6 decitex, which correspond approximately to diameters of about 15 and 25 micrometers, respectively. The amount of crimped bulking fibers included or blended with microfibers in a composite web of the invention will depend upon the particular use to be made of the web. Generally at least 10 weight-percent of the blend will be bulking fibers to provide the desired low weight for a given amount of thermal resistance, and preferably at least 25 weight-percent of the blend will be bulking fibers. On the other hand, to achieve good insulating value, especially in the desired low thickness, microfibers will account for at least 25, and preferably at least 50 weight-percent of the blend. For purposes other than thermal insulation, microfibers may provide a useful function at lower amounts, though generally they will account for at least 10 weight-percent of the blend. Stated another way, the weight ratio of microfibers to bulking fibers in webs of the invention to be used as thermal insulation will generally be between 9:1 and 1:3, and preferably between 3:1 and 1:1, though for other purposes, the ratio of microfibers to bulking fibers may extend to 1:9. Webs of the invention can be supplied in any desired thickness depending again on the particular use to be made of the web, but a convenient thickness is between about 4 and 100 millimeters. The loft or density 2 of the web can also be varied for particular uses, though generally the webs will have a loft of at least about 30 cubic centimeters/gram, and preferably of at least about 50 cubic centimeters/gram. Composite fibrous webs of the invention are resilient so that after they have been stored under compression and then released from compression they quickly recover a substantial part of their original thickness. Military specifications specify that fibrous insulating webs to be used for garments, sleeping bags, etc., should, after a 24-hour period of compression under a pressure of 0.4 kilogram per square centimeter, achieve a 90 percent recovery of original thickness, within one hour after release of compression. Webs of the invention generally satisfy that test. Fibrous webs of the invention may include minor amounts of other ingredients in addition to the microfibers are crimped bulking fibers. For example, fiber finishes may be sprayed onto a web to improve the hand and feel of the web. Or solid particles or non-crimped macrofibers may be included (see Braun, U.S. Pat. No. 3,971,373 for methods of inclusion) to add features provided by such particles or fibers. Solid materials added to the web generally lie in the interstices of the fiber structure formed by the microfibers and crimped bulking fibers, and are included in amounts that do not interrupt or take away the coherency or integrity of the fiber structure. The weight of the fiber structure minus additives is known as the "basis weight". This "basis weight" fiber structure, formed of microfibers and crimped bulking fibers, exhibits the resilient loftiness of a non-additive web of the invention. Loft of this "basis weight" fiber structure may be determined by following the process conditions used to prepare the additive-included web except for omitting introduction of the additives and measuring the loft of the resulting fiber structure. Additives, such as dyes and fillers, may also be added to webs of the invention by introducing them to the fiber-forming liquid of the microfibers or crimped bulking fibers. Fibrous webs of the invention may be used by themselves or in combination with other sheet materials such as a liner for use in garments. In addition, the web may be processed after formation, as by quilting it to improve its handling characteristics for use in garments. The invention will be further illustrated by the following examples: EXAMPLES 1-4 A series of composite fibrous webs of the invention were prepared on apparatus as shown in FIG. 1 of the drawing using polyethylene terephthalate blown microfibers 0.7-1.8 micrometers in diameter and 13-decitex, 3.4 centimeters-long, 40-percent-crimp polyethylene terephthalate staple fibers. A series of webs were prepared including 12 weight-percent staple fiber (example 1 in the table below), 25 percent staple fiber (example 2), 41 weight-percent staple fiber (example 3), and 65 weight-percent staple fiber (example 4), with the balance in each case being blown microfibers. The webs were 1.2 centimeters thick and had a loft as given in Table 1. The thermal resistance of the webs, as measured by Method 2 of footnote 1, and the thermal insulating efficiency by weight of each of the samples is listed in Table 1. For the sake of comparison, the table also includes Comparative Examples A and B, A being a web prepared from 100 weight-percent polypropylene blown microfibers averaging 1-2 micrometers in diameter, with a thickness and loft of 1.2 centimeters and 21 cubic centimeters/gram, respectively; and B being a commercially available web of polyester staple fiber (6.3 decitex, 5.5 centimeter long, 40 percent crimp; "Dacron 88" fibers available from duPont). Absolute values of thermal resistance for Comparative Examples A and B were determined on a guarded hot plate (Method 1 in footnote 1) and then used to calibrate the water calorimeter used to obtain the rest of the results. TABLE I______________________________________ Loft Thermal Thermal Insulating (cubic Resistance Efficiency by Weight centimeter/ (clo/ (x 10.sup.-3 clo-squareExample No. gram) centimeter) meter per gram)______________________________________ComparativeEx. A 21 1.8 3.81 52 1.85 9.62 71 1.85 13.23 72 1.77 12.74 71 1.34 9.6Comparative -Ex. B 104 0.9 9.0______________________________________ EXAMPLES 5-7 Three different composite fibrous webs of the invention were prepared using apparatus as shown in FIG. 1, from meltblown polypropylene microfibers that averaged 1-2 micrometers in diameter (with a few being in the 6-8 micrometer range) and polyethylene terephthalate fibers of three different diameters. In Example 5 the polyethylene terephthalate fibers were 7 decitex (25 micrometer diameter), 5.1-centimeter-long, 45 percent crimp; in Example 6, were 13 decitex (34 micrometer), 3.4-centimeter-long, 40 percent crimp; and in Example 7, were 60 decitex (74 micrometer), 6-centimeter-long, 25 percent crimp. The staple fibers were included in an amount as listed in Table II. The thermal resistance of the composite webs of Examples 5 and 6 was measured by Method 1 of footnote 1, and that of the web of Example 7 was measured by Method 2. Results were as given in Table II. TABLE II______________________________________Amount Thermal Insu-of Staple Loft Thermal lating Effici-Fiber (cubic Resistance ency by WeightEx. (weight centi- (clo/centi- (× 10.sup.-3 clo-squareNo. percent) meter/gram) meter) meter per gram)______________________________________5 37 78 1.8 146 34 94 1.8 177 31 76 1.7 13______________________________________ EXAMPLES 8-10 Composite fibrous webs of the invention were prepared in apparatus as generally described in FIG. 1 using 18-decitex (40 micrometer), 3.8-centimeter-long, 34-percent-crimp, polyethylene terephthalate staple fibers and microfibers, 70 percent of which were less than or equal to 0.8 micrometers in diameter and 30 percent of which were between 0.8 and 2 micrometers in diameter, and which were solution-blown from a solution comprising 18 percent polyacrylonitrile, 1 percent styrene, and 82 percent dimethylformamide. Three different webs were prepared using 10, 50 and 75 weight-percent, respectively, of the staple. The webs were 1.2 centimeters thick. The thermal resistance and thermal insulating efficiency by weight of the samples as measured by Method 1 of footnote 1 were as shown in Table III. TABLE III______________________________________Amount Thermal Loft Thermal InsulatingStaple Resistance (cubic centi- Efficiency by weightEx. (weight (clo-centi- meter (x 10.sup.-3 clo-squareNo. percent) meter) per gram) meter per gram)______________________________________8 10 2.5 44 119 50 1.56 130 2010 75 1.21 150 18______________________________________ EXAMPLES 11-12 Two composite fibrous webs of the invention were prepared using melt-blown polypropylene microfibers averaging about 1-2 micrometers in diameter and 30-decitex (52micrometers), 4.9-centimeters-long, 23-percent-crimp nylon staple fibers, each web including a different proportion of staple fiber as reported in TABLE IV. Thermal resistance values as measured on a guarded hot plate (ASTM D 1518-64) are reported in TABLE IV. TABLE IV______________________________________Amount Loft (cubic Thermal Thermal InsulatingStaple centi- Resistance Efficiency by WeightEx. (weight- meter (clo/centi- (× 10.sup.-3 clo-squareNo. percent) per gram) meter) meter per gram______________________________________11 11.5 60 1.7 1012 18.1 81 1.6 13______________________________________ EXAMPLE 13 A composite fibrous web of the invention was prepared using microfibers blown from a solution of polyacrylonitrile in dimethylformamide solvent, 70 percent being 0.8 micrometer or less, and the rest 2 micrometers or less in diameter, and 3-decitex (16 micrometer) 33-percent-crimp, 3.8-centimeters-long polyacrylonitrile staple fibers. The web included 42 weight-percent staple fiber and had a thickness and loft, respectively, of 1.2 centimeters and 103 cubic centimeter/gram. Thermal resistance measured by Method 2 was 1.7 clo per centimeter and the thermal insulating efficiency by weight was 17.6 × 10 -3 clo-square meter per gram. These values compare with a thermal resistance of 0.87 clo per centimeter and a thermal insulating efficiency by weight of 9.2 × 10 -3 clo-square meter per gram for a web made solely from the staple polyacrylonitrile fibers. FOOTNOTES (1) The clo is a unit of thermal resistance defined as the amount of thermal resistance provided by an arbitrarily selected standard set of clothing. It is defined mathematically as: ##EQU1## Values of thermal resistance reported in the specification have been measured in either of two ways as specified below; the 1.8 and 0.9 values reported in the second paragraph of the specification were measured by Method 1. METHOD 1 Measurement on a guarded hot plate in the manner described in ASTM S1518-64, with thickness measured as described in footnote 2 below. METHOD 2 Water calorimeter Three aluminum cylinders, 2.63 centimeters in diameter and 15.40 centimeters high, with a 3-centimeter-thick disc of cork insulation fit onto each end, are wrapped with layers of the test insulation to a thickness of 1.2 centimeters. The cylinders are then filled with 476 grams of water at 90° C. A thermometer and mixer bar are placed in the cans and each are placed on a magnetic mixer in an air conditioned room at 23 ± 0.5° C., and the temperature of the water in the cans and room temperature are recorded after 30 minutes and each 15 minutes thereafter for 4 hours. The cooling curves obtained are then fit to the following equation using the method of least squares. 1n Δ t = a - bT, where: Δ t = the difference between the temperature of water in the can and room temperature 1n = natural log T = time elapsed since the first reading in minutes a = experimentally determined intercept of the curve b = experimentally determined slop of the curve which is a function of the calorimeter design, thickness of insulation which is held constant and thermal resistance of the test insulation Since the absolute calculation of heat flow in this type of calorimetric measurement is difficult and subject to error, each run was made with two standard samples, which had been run on the guarded hot plate, and one unknown sample. By using a commercial polyester fiber web known to have a thermal resistance of 0.9 clo/centimeter and a 100% blown polypropylene microfiber web known to have a thermal resistance of 1.8 clo centimeter as standards, linear interpolation can be used to find the thermal resistance of test web thus: I = 0.9 + 0.9 [(b.sub.f - b.sub.x)/(b.sub.f - b.sub.m)] I = thermal resistance b f = slope of the experimentally measured curve for the commercial polyester fiber web b m = slope of the experimentally measured curve for the blown polypropylene microfiber web. b x = slope of the measured curve for the web being tested (2) Since some webs take on an initial compression set when first compressed, the following procedure is used to measure thickness and loft: A 10-centimeter by 10-centimeter section of web is cut and weighed to the nearest 0.01 gram and then placed under a flat plate and a weight of 40 kilograms (providing a pressure of 0.4 kilogram/square centimeter) for 24 hours, at which time the weight is removed and the sample allowed to recover undisturbed for 1 hour. The height is then measured using a plate and dial indicator exerting a total force of 14 gram (pressure of 1.4 × 10 -4 kilogram/square centimeter) on the web. From the weight and the thickness, the loft is easily calculated from the following equation: L = (h) (100)/W where: L = loft in cubic centimeter/gram h = thickness in centimeter W = weight of 10-centimeter-by-10-centimeter sample
Mixtures of microfibers and crimped bulking fibers produce a lofty resilient web having properties that are unique for microfiber-based webs. Included in these properties are a combination of high thermal resistance per unit of thickness and moderate weight, as well as other properties which give the web a distinctive utility as thermal insulation.
3
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to the transfer of electrostatically formed toner images using an intermediate transfer member and in particular, to creation of multicolor toner images with small particle toners using an intermediate transfer member with a surface sectioned to enhance the transfer of the toner particles. 2. Description of the Prior Art The use of an intermediate transfer member is useful in electrophotography for a number of reasons, including simplified receiving sheet handling, single pass duplexing, saving wear on photoconductors, and superposition of images to form multicolor images. Typically, a toner image is created on a photoconductive member electrophotographically and is then transferred to an intermediate transfer member, such as a roller or web. For example, a negatively charged toner image is transferred from a photoconductor having an electrically grounded backing electrode, to an intermediate web or roller biased to a strong positive polarity. The toner image is then transferred from the intermediate member to a receiving sheet under the influence of a second electric field. The second electric field can be created, without changing the voltage on the intermediate member, by placing a roller behind the receiving sheet, which is biased in a stronger, positive direction. The most desirable use of intermediate transfer is for creating multicolor images. When an intermediate transfer member is used, two, three, four or more separate images of different color can be transferred in registration to the intermediate transfer member to create a multicolor image. The multicolor image can then be transferred in one step to the receiving sheet. This system has a number of advantages over the more conventional approach to making multicolor images in which the receiver sheet is secured to the periphery of a roller and rotated repeatedly into transfer relation with the photoconductor to receive the color images directly. The most important advantage is that the receiving sheet itself does not have to be attached to a roller. Attaching the receiving sheet to a roller has been a source of misregistration of images due to independently transferring each color image to the receiver, as well as complexity in apparatus. Other advantages, such as wear and tear on the photoconductive member and a straight and simple receiving sheet path are also important. High resolution in electrophotographic color printing is desirable. In order to obtain higher resolution, fine toners are necessary. Toners less than 10 μm in size give substantially improved resolution in color imaging with high quality equipment. Unfortunately, fine toners are more difficult to transfer electrostatically than are traditional coarse toners. This is a problem using both single transfer and intermediate transfer members. When transferring toners having a volume weighted average diameter less than 12 μm, and using electrostatics at both transfers, a number of transfer artifacts occur. For example, a well known artifact called "hollow character" is a result of insufficient transfer in the middle of high density toned areas, e.g., in alphanumerics. Another artifact, "halo" is experienced when toner fails to transfer next to a dense portion of an image. These problems cannot be eliminated merely by an increase of the transfer field, since that expedient is limited by electrical breakdown. Another problem is that typical receivers have a surface roughness with surface irregularities having larger dimensions than the diameters of the small toner particles, as shown in FIG. 1. In some areas, particles 12 will be adjacent to peaks 13 in the roughness profile of the receiver 14 while others will be adjacent to valleys 15. When surface forces are balanced or nearly balanced, the applied electrostatic transfer force determines which surface the particle remains attached when the surfaces are subsequently separated. Particles near the receiver peaks will contact both surfaces and will transfer to the receiver presumably because of the balancing of surface forces. Particles adjacent to valleys in the receiver never contact the receiver and do not transfer because the surface forces are not balanced. In this case the electrostatic force on the small particles cannot be made large enough to overcome the surface forces holding the particles to the imaging surface because of the limitation imposed by electric field breakdown. See Schaffert, R. M., Electrography, Focal Press, New York, 1975, pp. 514-518. Incomplete transfer can also be caused by toner particles having varying sizes. Larger toner particles, shown in FIG. 2, may contact both transfer surfaces while nearby smaller particles 17 do not. Larger particles, therefore, are preferentially transferred. (To simplify the description, both transfer surfaces shown are smooth in FIG. 2.) A similar problem occurs when stacks of large toner particles are adjacent to stacks of smaller toner particles. These effects are compounded by the previously described problem of rough receivers. Both effects contribute to a reduction in transfer efficiency and degradation in the granularity of the image, especially in areas with low toner densities. Rimai and Chowdry have shown that by avoiding air gaps between toner and receiver, the surface forces can be at least partially balanced, thereby permitting images made using small toner particles to be transferred with high efficiency. See Rim and Chowdry, U.S. Pat. No. 4,737,433. See, also, Dessauer and Clark, Xerography and Related Processes, page 393, Focal Press (N.Y.), N. S. Goel, and P. R. Spencer, Polym. Sci. Technol. 9B, pp. 763-827 (1975). Use of a simple compliant intermediate transfer member improves transfer efficiency compared to a non-compliant intermediate transfer member because it conforms to the variations in the roughness of the receivers and to any peaks caused by particulate contamination. One attempt to solve the small toner transfer problem is disclosed in Rimai et al, U.S. Pat. No. 5,084,735 and Zaretsky, U.S. Pat. No. 5,187,526. These patents disclose the use of an intermediate transfer member with a compliant intermediate blanket with a thin overcoat, which has a higher Young's modulus than the underlying blanket. The blanket gives compliance, whereas the overcoat controls adhesion. At a transfer point, the compliant blanket, under pressure, conforms to the profile of a relatively rough receiver, which balances the surface forces, and the thin, hard overcoat improves the release properties of the toner. The overcoat is necessary because the compliant blanket is too "sticky" to allow the toner to be transferred to a receiver, usually paper, and particles become embedded in the soft material of the compliant blanket, thereby increasing the surface holding force. This adhesive force cannot be balanced by the surface forces attracting the particles to the receiver. When a composite intermediate transfer member, comprised of a soft blanket with a hard overcoat, is in the form of a belt or drum, uncontrolled cracking and delamination of the hard, thin overcoat may occur. Cracking of the overcoat occurs because the hard overcoat cannot stretch when the intermediate transfer member is deformed by another contacting drum or roller. Such cracks in the overcoat introduce defects in the image. One attempt to remedy this problem is disclosed in U.S. Ser. No. 08/648,846 in which the hard, thin overcoat is sectioned into small segments which remain bonded to the compliant blanket. The method and apparatus disclosed may be degraded if the space between the small segments is larger than the diameter of the toner particles. Also, the point at which toners are applied to and cleaned from the intermediate transfer member are important when the hard thin overcoat is sectioned into small segments because the small diameter toner particles may become lodged in the crack between the sections if the intermediate transfer belt is flexed at the time of transfer or cleaning. SUMMARY OF THE INVENTION It is the object of the invention to provide a method and apparatus for transferring toner images electrostatically from a first image member, to an intermediate transfer member, and then to a receiving sheet with a minimum of image defects and a maximum of toner transferred. The above and other objects are accomplished by forming a toner image on a receiving sheet in which an electrostatic image is first formed on a primary image member. The electrostatic image is toned with a dry toner to form a toner image, and the toner image is transferred from the primary image member in the presence of an electric field urging toner particles from the primary image member to the intermediate transfer member. The toner image is then transferred from the intermediate transfer member to a receiving sheet in the presence of an electric field urging the toner particles from the intermediate transfer member to the receiving sheet. The invention is characterized by an intermediate transfer member comprised of a substrate, a relatively thick compliant blanket of elastomeric material, and a hard, thin surface overcoat sectioned into segments. According to a preferred embodiment, the segments are formed by breaking the hard overcoat into discrete, small segments which remain bonded to the compliant blanket, and the space between the segments is less than the average weighted diameter of the toner particles. The invention enhances the micro-compliance of the intermediate transfer member without allowing a significant amount of toner particles to become trapped in the space between the segments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is cross-sectional view of a prior art intermediate transfer member and receiver showing surface irregularities on the receiver. FIG. 2 is a cross-sectional view of a prior art intermediate transfer member and receiver showing toner particles having a variety of sizes. FIG. 3 is a schematic side view of a color printer apparatus utilizing the invention. FIG. 4 is a cross-section of a portion of an intermediate transfer drum constructed according to the invention. FIG. 5 is a cross-section of a portion of an intermediate transfer member in the form of a web according to an alternate embodiment of the invention. FIGS. 6(a)-6(d) are top plan views of sectioned overcoats on an intermediate member according to the present invention. FIG. 7 is a cross-sectional view of an intermediate transfer member according to the present invention. FIG. 8 is a cross-sectional view of an intermediate transfer roller according to the present invention. FIG. 9 is a cross-sectional view of an alternate embodiment of an intermediate transfer web according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 3 illustrates an apparatus 20 in which the invention is intended to be used. A primary image member 21, for example, a photoconductive web, is trained about rollers 27, 28, and 29, one of which is drivable to move primary image member 21 past a series of stations well known in the electrophotographic art. Primary image member 21 is uniformly charged at a charging station 33, imagewise exposed at an exposure station 34 by means of, for example, an LED print head or laser electronic exposure station, to create an electrostatic latent image. The latent image is toned by one of toner stations 35, 36, 37, or 38 to create a toner image corresponding to the color of toner in the station used. The toner image is transferred from primary image member 21 to an intermediate transfer member, for example, an intermediate transfer drum 42, at a transfer station formed with roller 28. Primary image member 21 is cleaned at a cleaning station 49 and reused to form more toner images of different colors, utilizing toner stations 35, 36, 37, and 38. One or more additional images are transferred in registration with the first image transferred to intermediate transfer drum 42, to create a single or multicolor toner image on the surface of transfer intermediate transfer drum 42. The single or multicolor image is transferred to a receiving sheet which has been fed from supply 50 into transfer relationship with intermediate transfer intermediate transfer drum 42 at transfer station 51. The receiving sheet is transported from transfer station 51 by a transport mechanism 52 to a fuser 53 where the toner image is fixed by conventional means. The receiving sheet is then conveyed from the fuser 53 to an output tray 54. The toner images are transferred from the primary image member 21 to the intermediate transfer intermediate transfer drum 42 in response to an electric field applied between the core of intermediate transfer drum 42 and a conductive electrode forming a part of primary image member 21. The multicolor toner image is transferred to the receiving sheet at transfer station 51 in response to an electric field created between a backing roller 56 and transfer intermediate transfer drum 42. Thus, intermediate transfer drum 42 helps establish both electric fields. As is known in the art, a polyurethane roller containing an appropriate amount of anti-static material to impart some conductivity can be used for establishing both fields. Typically, the electrode buried in primary image member 21 is grounded for convenience in cooperating with the other stations in forming the electrostatic and toner images. If the toner is a positively-charged toner, an electrical bias applied to intermediate transfer intermediate transfer drum 42 of typically -200 to -1500 volts will effect substantial transfer of toner images to intermediate transfer drum 42. To transfer the toner image onto a receiving sheet at transfer station 51, a bias of about -3000 volts, is applied to backing roller 56 to again urge the positively charged toner to transfer to the receiving sheet. Schemes are also known in the art for changing the bias on intermediate transfer drum 42 between the two transfer locations so that the bias of roller 56 need not be at such a high potential. A partial cross-section of a preferred embodiment of a transfer intermediate member is shown in FIG. 4 in which the intermediate transfer drum 42 has a compliant blanket 19, comprised of an elastomeric material such as polyurethane. The compliant blanket 19 has a thickness of greater than 0.1 mm and the thickness is preferably in the range of 2 mm to 30 mm. The compliant blanket 19, supported by a drum 60 is fabricated of a rigid material such as aluminum. The compliant blanket 19 must be flexible enough to conform to the irregularities encountered in electrostatic toner transfer. This is accomplished by using an elastomeric material that has a Young's modulus of between 0.5 MPa. (MegaPascals) and 10 MPa. Preferably, the Young's modulus of the compliant blanket should lie between 1.0 MPa. and 5 MPa. The compliant blanket of the intermediate transfer member typically would not be insulative so that an electric field could be applied to cause transfer. The optimum resistivity of the elastomeric blanket is affected by the thickness of the intermediate transfer member, the speed of the process, and the geometry of the transfer system. The elastomeric material should have an electrical resistivity between about 10 6 ohm-cm and about 10 12 ohm-cm, and preferably between about 10 8 and about 10 10 ohm-cm. Examples of suitable materials for the compliant blanket include but are not limited to: polyurethane, silicone rubber, and silicone foam. A hard, sectioned overcoat having a Young's modulus ≧0.1 GPa, 80 is formed on top of the compliant blanket 19. Increased compliance of the intermediate transfer member is achieved, without affecting the release properties of the overcoat, by sectioning the hard, thin overcoat in a controlled manner, creating cracks which extend through the overcoat. Cracks 85 penetrate the overcoat 80 from a top surface to compliant blanket 19. The average width of the cracks 85 should be less than 20 μm on a flat portion of the intermediate, preferably, having an average crack width less than 12 μm, and more preferably less than 6 μm. The crack width refers to the unstretched intermediate and can be measured using standard techniques such as a atomic force microscopy, optical microscopy or scanning electron microscopy. The segments 81 are free to move somewhat independently of the surrounding sections as shown in more detail FIG. 5. This independence of movement enhances the micro-compliance of the intermediate transfer member when compared to an intermediate transfer member having a continuous overcoat. The sectioned overcoat can be formed on the intermediate transfer member in many different ways, all of which enhance micro-compliance. Examples of methods of sectioning the overcoat include etching, either chemically, with laser, or other radiation; cracking the layer in a controlled manner with mechanical means, such as bead-blasting, rolling the surface across a dimpled surface or, in the case of a belt, simply running the belt over a roller of small diameter, and under tension; or by selection of an appropriate solvent in cases where the overcoat is a thermoplastic. To achieve cracking by the mechanical method recited, the ratio of the thickness of the intermediate transfer member to the diameter of the roller should be greater than 0.1 and, preferably, greater than 0.2. The tension on the web belt is not critical. The shape of the segments 81 of the overcoat are not critical and can be regularly shaped, e.g., square, hexagonal, or rectangular, as shown in FIGS. 6(a) and 6(b), or they can be irregular, as shown in FIG. 6(d). Long, thin segments would also be acceptable as shown in FIG. 6(c). It is preferred that the longest dimension of each segment be less than 3 mm, regardless of the shape. For very high quality imaging, even smaller segments are preferred, wherein the largest dimension of any segment is less than 0.3 mm so that any resultant sectioning of the final image is not perceptible by the human eye. The thickness of the sectioned overcoat should be between 0.1 and 30 μm and preferably between 1 and 10 μm. Many materials are suitable for the overcoat and examples include but are not limited to: polyurethane, and diamond-like carbon. The Young's modulus of the sectioned overcoat should be significantly larger than the underlying blanket and is preferably greater than 0.1 GPa=100 MPa. The electrical resistivity of the sectioned overcoat is not an important consideration when the overcoat is very thin. However, it is preferred that the resistivity be in the range of 10 7 ohm-cm and 10 13 ohm-cm. The overcoat should be strongly bonded to the compliant blanket to preclude delamination. A preferred method is to coat layers of the polymer overcoat material on the compliant blanket so that the polymer chains of the layers are interpenetrating. Sol-gel technology may be used to deposit the overcoat on the compliant blanket. Sol-gel refers to material that is actually gelatinous when applied, but a solid when cured. Alternatively, other methods, such as chemical bonding and the use of adhesion promoters or adhesives, could be used. The multilayer structure comprised of compliant blanket and overcoat, described above, must reside on a supporting layer, such as a drum or a web. When employing an electrostatic transfer means, the support should be sufficiently conductive so that a voltage applied to it affects transfer of the toned image. In an alternative embodiment, a conducting layer 82 is isolated between the supporting layer and the compliant blanket, as shown in FIG. 7. The transfer bias would then be applied to the conducting layer. The intermediate transfer member structure described is suitable for use as a drum or a web belt. The intermediate transfer member, when it takes the form of a web belt 86 shown in FIG. 7, can be made to traverse an irregular path. For use as a web belt, the intermediate transfer member consists of a compliant blanket 19 and an overcoat 80 with the properties described above, optional conducting layer 82, and backing member 84. It is preferred, however, to incorporate backing member 84 adjacent to the compliant blanket 19. Backing member 84 consists of a flexible material having a Young's modulus greater than 1 GPa (GigaPascal) and serves as a support for the elastomeric blanket 19. When used without conducting layer 82, this material should be sufficiently conductive so as to allow the intermediate transfer member to be electrically biased. In this embodiment, the transfer bias can be applied using techniques such as incorporating electrically biased, conducting back-up rollers in the transfer nips. Suitable backing member materials include nickel and stainless steel, which can be made sufficiently thin so as to allow them to flex around any rollers and angles encountered in the path of the web. Alternatively, polymers or other materials having suitable Young's modulus and flexibility are also acceptable. If the material used for the backing member is electrically insulating, it should be coated with an electrically conductive layer such as evaporated nickel on the side contacting the compliant blanket. It is preferable, however, to use a semi-conducting support, such as a polymeric material, having a sufficiently high Young's modulus, doped with a charge transport material, such as those described in U.S. Pat. Nos. 5,212,032; 5,156,915; 5,217,838; and 5,250,357. This allows the voltage applied to the web to be varied spatially. When using the intermediate transfer member structure defined here, the problem of image defects is minimized. The sectioning of the overcoat allows the outer surface of the intermediate transfer member to stretch when it travels over rollers because the coating is essentially comprised of separate segments which are free to move independently. The average crack width between segments is important. A hard, sectioned overcoat having a Young's modulus ≧0.1 GPa, 80 is formed on top of the compliant blanket 19. Increased compliance of the intermediate transfer member is achieved, without affecting the release properties of the overcoat, by sectioning the hard, thin overcoat in a controlled manner, creating cracks which extend through the overcoat. Cracks 85 penetrate the overcoat 80 from a top surface to compliant blanket 19. The average width of the cracks 85 should be less 20 μm on a flat portion of the intermediate, preferably, having an average crack width less than 12 μm, and more preferably less than 6 μm. The crack width refers to the unstretched intermediate and can be measured using standard techniques such as a atomic force microscopy, optical microscopy or scanning electron microscopy. As shown in FIG. 8, when the intermediate transfer member is in the form of an intermediate transfer drum, the crack width typically varies during transfer of the toner from the photoconductor to the intermediate transfer member, or from the intermediate transfer member to a receiver, because the intermediate transfer member is compressed. When the intermediate transfer member is in the form of a web, however, the crack width increases when the web traverses supporting rollers 100, as shown in FIG. 9. To prevent the toner from lodging in the cracks under this circumstance, cleaning of the intermediate transfer member should take place only when the web is flexed in a manner that reduces the crack width thus cleaning roller 92 should be placed as close as practical to backing roller 56 while the web 86 is flexed in the direction shown which tends to close the cracks between the segments 81. Placing cleaning roller adjacent to either of the support rollers 100 should be avoided since web 86 flexes in the direction which would tend to widen the cracks between the segments 81. In a similar manner the toned image should be transferred to the intermediate transfer member 86 at a location where the sectioned overcoat is not flexed in a manner which would separate the segments 81 as shown in FIG. 9 and a photoconductor drum 102 is used with a soft back up roller 104 to transfer the toned image to intermediate transfer member 86 at a location where the sectioned overcoat 80 is not flexed by transfer rollers 100. EXAMPLE 1 An intermediate transfer system which included a photoconductive element, a roller and a backup roller was constructed according to the present invention. The photoconductive element was an organic photoconductor such as those found in the Kodak 2100 copier duplicator. The intermediate transfer member consisted of a compliant blanket and a sectioned overcoat over an aluminum core. The compliant blanket was 5.1 mm thick and was composed of polyurethane doped with an antistatic material to yield a resistivity of 10 9 ohm-cm. The Young's modulus of the compliant blanket was 2 MPa. The overcoat was a urethane resin sold under the trade name Permuthane® by Stahl Finish. The thickness of the overcoat was 12 μm, the Young's modulus was 320 MPa, and the resistivity was 10 12 ohm-cm. The diameter of the intermediate transfer member was 146 mm. The intermediate transfer member was prepared as follows. TU-400 is a commercially available two part polyurethane system from Conap, Inc., Olean, N.Y. TU-400 Part A is a polyisocyanate resin, and TU-400 Part B is a hardening agent consisting primarily of a chain extender and a catalyst. An antistat comprising a complex of one mole sodium iodide with three moles diethylene glycol was prepared. To a three liter glass kettle containing 7.876 grams antistat, 1041.240 grams TU-400 part B were added. The mixture was mechanically stirred for three minutes at room temperature. Then 1601.18 grams of TU-400 Part A were added to the kettle and the reaction was mixed under nitrogen for five minutes. The incorporated nitrogen was removed under reduced pressure (0.1 mm Hg) and the mixture was poured into a prepared mold with a roller core in the middle. The polyurethane was cured at 80° C. for sixteen hours. After eighteen hours, the roller was removed from the mold and ground to 14.6 cm in diameter. The roller was then overcoated with 12 μm layer of Permuthane U6729. The irregular segments on the overcoat were made by rolling a hard, small diameter roller across the overcoat at high pressure. The resulting segments formed in the overcoat had dimensions ranging from about 0.1 mm to 0.5 mm and the average width of the cracks between the segments was approximately 6.8 μm. To achieve transfer from the intermediate transfer member to the receiver, the receiver was passed through nip formed by the intermediate transfer member and a backing roller. The backing roller consisted of a steel core, with a layer of polyurethane doped with antistat to achieve a resistivity of 2×10 9 ohm-cm. The thickness of the polyurethane layer on the backing roller was 5.1 mm and the Young's modulus was 40 MPa. The diameter of the backing roller was 37 mm. The marking toner was comprised of a 3.5 micron, volume weighted diameter dry toner made by the limited coalescence process (silica stabilized). The binder was Piccotoner® 1221 binder, a styrene butylacrylate copolymer (80/20), available from Hercules Sanyo Inc. The pigment was bridged aluminum phthalocyanine, 12.5% by weight of the toner. The charge agent was tetradecylperidinium tetraphenyl borate, 0.4% by weight of the toner. The charge to mass ratio of the toner was 62 μC/g (micro Coulombs per gram) and the toner concentration of the developer was 6% by weight of the developer. The marking toner had 0.1 μm diameter silica particles, adhering to its surface, comprising 0.5% by weight based on the weight of the toner particles. The brand of these particles is T604, available from DeGussa Corp. The silica particles were dry blended using a Hobart mixer with the toner particles to achieve a uniform distribution of adhered or embedded or both, transfer assisting particles on the toner particles. Materials suitable for transfer assisting addenda particles include titanium dioxide and magnetite. An acceptable range for the diameter of the transfer assisting addenda particles is 0.03 to 0.2 μm. The carrier was a lanthanum doped, hard ferrite core coated with a 1:1 blend of a polyvinylidene fluoride, Kynar 301F (Penwalt Corp.) and polymethylmethacrylate made as described in U.S. Pat. No. 4,764,445. The method of depositing the toner onto the photoconductor was the same as the process used in the Kodak ColorEdge copier duplicator, a product previously manufactured by the Eastman Kodak Company. The marking toner was developed on a single frame of the photoconductor to yield a toner scale or patches having a range of image densities. The marking toner frame was then transferred to the intermediate transfer member by applying -700V to the core of the intermediate transfer member. The patches were then transferred to a clay coated paper, Krome Kote®, produced by Champion, Inc. in the transfer nip formed by the intermediate transfer member and the backing roller by applying a potential difference of 2300V between the intermediate transfer member and the backup roller. The sectioned overcoat introduced no defects or image degradation in the print, and excellent transfer efficiency was demonstrated. EXAMPLE 2 Example 2 used the same process and parameters as in Example 1 except that a different intermediate transfer member and different marking toner were used. The intermediate transfer member was a roller consisting of a compliant blanket layer and an overcoat. The compliant blanket consisted of polyurethane material doped with antistatic material having a resistivity of 4×10 8 ohms-cm, a thickness of 5.1 mm, and a Young's modulus of 3.8 MPa. The overcoat consisted of a 12 mm thick layer of Permuthane® available from Stahl Finish. The intermediate transfer member was prepared as follows. L42 is a polyisocyanate resin available from Uniroyal. EC-300 is an amine chain extender available from Ethyl corporation. An antistat complex comprising one mole ferric chloride and three moles diethylene glycol, was added to a three liter glass beaker containing 0.437 grams tetraethylene glycol, and the mixture was stirred for five minutes. Then 846.76 grams of L42 resin were added and the reaction was stirred for two minutes. Then 9.53 grams of EC-300 were added, and the reaction was stirred for five minutes. Then the air was removed under reduced pressure (0.10 mm Hg). The resulting mixture, which is a type of polyurethane, was poured into a prepared mold with a roller core in the middle and was cured at 80° C. for eighteen hours. The roller was removed from the mold and ground to a diameter of 14.6 cm. The roller was then overcoated with a 12 micron layer of Permuthane U6729. The sectioned overcoat was formed as in Example 1. The harder blanket resulted in smaller segments which averaged about 0.3 mm in length and 0.1 mm and the average width of the crack between the segments is approximately less than 10 μm. The sectioned overcoat introduced no defects in the final print and excellent transfer efficiency was demonstrated. The marking toner was the same as in Example 1 except that it had no silica transfer assisting addenda. An acceptable range for the diameter of the transfer assisting addenda particles is 0.03 to 0.2 μm. The invention has been described in detail with particular reference to preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as set forth in the claims. For example, it's expected that toner particles will have a volume weighted average diameter between 1 and 10 microns and preferably between about 3 to 8 microns. ______________________________________PARTS LIST______________________________________12. Toner particles 81. Segments13. Peaks 82. Conducting layer14. Receiver 84. Backing member15. Valleys 85. Cracks16. Large Particles 86. Web17. Small particles 92. Cleaning roller18. Overcoat 100. Support roller19. Compliant blanket 102. Photoconductor drum20. Apparatus 104. Soft back up roller21. Primary Image member or Photoconductive web27. Roller28. Roller29. Roller33. Charging station34. Exposure station35. Toner station36. Toner station37. Toner station38. Toner station42. Intermediate transfer drum49. Cleaning station50. Supply51. Transfer station52. Transport mechanism53. Fuser54. Output tray56. Backing roller60. Intermediate transfer drum80. Sectioned overcoat______________________________________
A particle toner image is formed on a primary image member (21), such as a photoconductor; electrostatically transferred to an intermediate transfer member (42); and then electrostatically transferred to a receiving sheet. The intermediate transfer member (42) includes a substrate, a compliant blanket (19), and a thin, hard overcoat (80) sectioned into small, discreet segments (81), said segments being separated cracks (85) having a width less than 20 μm
6
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to impact printing and in particular to impact printers in which dots are recorded on a print medium to form images, lines, symbols or the like. 2. Discussion of the Prior Art In a dot matrix printer, which in some cases may also be referred to as an all-points addressable dot printer, individual dots are recorded selectively at all addressable point positions in a continuous line of dots extending across a record medium. In order to produce recorded images of good print quality, the recorded dots must be precisely located and uniformly spaced at all addressable points of the line and it is desirable to be able to record successions of spaced dots as closely together as possible. In the multiple blade and helix printers of the type for printing characters, a separation or gap exists between the print elements or type-carrying elements to permit interference-free individual operation. To enhance interference-free individual operation, the prior art shows the use of an over-under hammer and print element structure. This type of structure generally involves the use of carrier elements having engraved characters on the front side and projections alternatively arranged on two levels on the backside, with respect to the print medium. The carrier elements are mounted for movement along a print line. Hammers for striking the projections are arranged in superimposed fashion in two rows, one row being on an upper level and the other row being on a lower level. U.S. Pat. No. 3,698,529 describes a back-printer using a stationary interposer with over-under projections that are acted on by hammers which move on a carriage and uses a wheel containing engraved characters which moves along with the hammers to accomplish serial printing. This arrangement would be unsatisfactory for use as a dot matrix line front printer which must print using a plurality of hammers simultaneously. Also, there is difficulty in moving the relatively massive hammers. U.S. Pat. No. 3,719,139 describes a high-speed printer wherein the type-carrying member is provided with staggered rows of projections (over-under) on the reverse side of each type character and wherein a plurality of hammers operating at a print position selectively cooperate with the projections of a respective row. Both the type carrying members and the hammers are moved and the printing elements are presented in sequence to carry out serial printing. This arrangement would not be adaptable for use as a dot matrix printer wherein many positions are printed simultaneously. U.S. Pat. No. 3,773,161 describes a high speed on-the-fly serial printer wherein character printing is accomplished one character at a time along a succession of printing positions. A print carriage is movable from one printing position to the next. A pair of printing hammers are mounted on the printing carriage and they are arranged on two levels so that the two printing heads are partially overlapping. This arrangement would also be unsatisfactory for use as a dot matrix line front printer which must print many positions simultaneously. Also, it is desirable to have hammers which are stationery. The over-under hammer and print element structures in the above prior art are satisfactory to permit interference-free individual operation. The blade separation presents little problem for character printing since such printing naturally requires some separation between characters for legibility. However, in the all-points addressable printing of dots, the present invention uses a plurality of fixed cantilevered hammer elements which co-act with a plurality of cantilevered print elements which are mounted on a reciprocating shuttle. With the use of a reciprocating shuttle, it became apparent that an over-under arrangement for the hammer elements and print elements was required which would prevent interaction between adjacent print elements and which also would prevent the crashing between impactor bars and impact receiving bars when the shuttle reached the end of its movement in one direction and then reversed to move in the opposite direction. SUMMARY OF THE INVENTION In a preferred embodiment of the present invention, there is provided a dot matrix printer having a row of fixed uniformly spaced cantilevered hammer elements. The hammer elements alternately have horizontal impactor bars aligned at upper and lower levels in an over-under fashion, and in partial overlapping relation with adjacent impactor bars. A row of uniformly spaced cantilevered print elements are provided which have upper and lower non-overlapping horizontal impact receiving bars aligned at upper and lower levels, in an over-under fashion, and positioned opposite the hammer elements and which are impacted by corresponding upper and lower level impactor bars on the hammer elements for transverse deflection to form dot impressions on print lines of a print medium. The print elements have dot producing print elements thereon which face the print medium. A row of suitable hammer magnets is provided for actuating the hammer elements. The hammer elements are fixed and have no horizontal movement, whereas, the print elements are mounted on a horizontally reciprocating shuttle which is driven back and forth by a cam mechanism whereby the print element impact receiving bars move back and forth across the hammer element impactor bars. The shuttle moves horizontally, in either direction, a distance which is only slightly greater than one dot pitch which is the center-to-center distance between dots. There are a pair of hammer magnets provided for each hammer element and a dot producing element on each print element. As the shuttle moves back and forth, the hammer elements may act on the print elements at anytime to produce dots on the print medium at horizontal positions which are predetermined by suitable control logic. This is accomplished by providing overlapping of the over-under arrangement of the impactor bars on the hammer elements. The position of the shuttle may be sensed by emitter signals which can be produced by an optical or magnetic emitter means. An ink ribbon is provided between the dot producing elements and the print medium, such as, paper which is supported and is indexed vertically by an indexing platen or other suitable means. In all cases, the reciprocating impact receiving bars on the print elements never move horizontally off of its corresponding impactor bars on the hammer elements. This is very desirable since it precludes the nipping problem that is applicable to printers having hammers which act on dot producing elements that move serially in front of the hammers. Also, sufficient overlap of the impactor bars is provided to assure that when the last print position is passed, that all print elements impact receiving bars do not fall off the edge of the impactor bars on the corresponding hammer elements. This prevents crashing between the impactor and impact receiving bars upon reversal of shuttle motion. And because the impactor bars on the hammer elements are arranged in an over-under fashion, no interaction will take place due to the actuation of adjacent hammer elements. Accordingly, a primary object of the present invention is to provide a novel and improved dot matrix printer. Another object of the present invention is to provide an improved dot matrix printer which comprises a row of fixed hammer elements and a row of print elements mounted on a reciprocating shuttle. A further object of the present invention is to provide an improved dot matrix printer which comprises a novel over-under hammer element and print element structure. A still further object of the present invention is to provide an improved dot matrix printer which comprises a row of fixed spring hammer elements alternately having horizontal impactor bars aligned at upper and lower levels and in partial overlapping relation with adjacent impactor bars, and a row of reciprocating spring print elements alternately having upper and lower non-overlapping impact receiving bars positioned opposite the hammer elements for being impacted by corresponding alternate upper and lower impactor bars on the hammer elements for transverse deflection to form dot impressions on a print medium. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged partial front view of the hammer element and print element arrangement of the present invention showing the front sides of the hammer elements and the overlapping over-under arrangement of the impactor bars thereon and also showing the front sides of the print elements with the dot print elements thereon. FIG. 2 is a full scale view showing the back sides of the print elements and showing the non-overlapping over-under arrangement of the impact receiving bars thereon and also showing the cam mechanism for reciprocating the print blades. FIG. 3 is an enlarged end view of the hammer element and print element arrangement and the hammer magnet assembly and the print receiving structure. FIG. 4 is a front view similar to FIG. 1 and showing the position of the print elements when the shuttle reaches the end of its travel towards the left, as viewed from the print plane. FIG. 5 is a block circuit diagram for effecting selective release of the hammer elements. FIG. 6 is a view looking down on the top of an impactor bar, an impact receiving bar, and the top edge of the print paper. DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, there is shown the hammer element and spring element arrangement of the present invention. The arrangement comprises a row of uniformly spaced cantilevered hammer elements 10 which are fixed at one end in the manner of elastic cantilever beams by a suitable means such as clamping plate 11 and screws 12. The plate 11 and screws 12 attach the bottom strip portion of the hammer elements to the base of a hammer magnet assembly which will be later described. The hammer magnet assembly is attached by screws 13 to a support bar 14 which is suitably attached to the machine frame. Although only a few hammer elements are shown, it will be understood that the row could comprise any number of elements depending upon the printing requirement. For example, in one printing application, there would be 45 hammer elements used. The hammer elements are preferably fabricated from a single sheet of magnetically premeable material such as 8620 steel. Arranged on an upper level is a row of protruding impactor bars 15, there being one impactor bar 15 welded to the front side of each one of alternate hammer elements. Also, arranged on a lower level is a row of similar protruding impactor bars 16, there being one impactor bar 16 welded to the front side to each one of the other alternate hammer elements. This is referred to as an over-under arrangement. It will be noted that the impactor bars 15 partially overlap the adjacent impactor bars 16 and that the impactor bars 15 and 16 do not overlap their adjacent hammer elements. Arranged above the row of hammer elements is a corresponding row of uniformly spaced cantilevered print elements 17 with the lower ends of the print elements partially overlapping their corresponding hammer elements. Attached to the front or printing side of each print element is a dot print element 18 for recording dots on a print medium. The print elements are also preferably fabricated from a single sheet of magnetically permeable material such as 8620 steel. The print elements are fixed at one end in the manner of elastic cantilever beams at uniformly spaced positions by wrapping the base strip portion 19 partially around an elongated hollow cylinder 20 and attaching it thereto. Attached to each end portion of the cylinder 20 is a rod 21. If desired, a single rod could be used which extends through the cylinder and beyond the ends of the cylinder. Referring to FIG. 2, the print elements 17 of FIG. 1 are now shown flipped over to more clearly show the back sides of the print elements which face the front sides of the hammer elements. Arranged on an upper level is a row of protruding impact receiving bars 22, there being one impact receiving bar 22 welded to the back side of each one of alternate print elements, the bars 22 being aligned opposite to their corresponding upper level impactor bars 15 on the hammer elements. Also, arranged on a lower level is a row of similar impact receiving bars 23, there being one impact receiving bar 23 welded to the back side of each one of the alternate print elements, the bars 23 being aligned opposite to their corresponding lower level impactor bars 16 on the hammer elements. Upper and lower level bars 22 and 23 do not overlap each other. Also, shown in FIG. 2 is the cam mechanism for reciprocating the cylinder 20 and rods 21 which form a shuttle to which the print elements are fixed. The rod 21 at one end of the cylinder extends through the ball and sleeve portion 24 of a linear/rotary bearing block 25 and is slideable therein. Bearing block 25 has a base portion 26 which is suitably fastened to the machine frame. Rod 21 extends beyond the bearing block and the end portion of the rod has plate 27 loosely mounted on the rod and also a plate 28 which is fixed on the rod. A compression coil spring 29 is mounted on the rod between the plates 27 and 28. Plate 28 has an arm 30 which rotatably supports a cam follower roller 31. The roller 31 co-acts with the periphery of an elliptical cam 32 fixed on a shaft 33 which is rotated by a suitable motor, not shown. The rod 21 at the other end of the cylinder, not shown in FIG. 2, would also be slideably mounted in a similar linear/rotary bearing block suitably fastened to the machine frame. As viewed in FIG. 2, the cam follower is forced against the low rise point 2 on the cam by the compression spring. In this position, the spring has driven the shuttle and print elements to the end of their travel to the left. As the cam rotates clockwise, it will cause the cam follower to move toward the right against the force of the compression spring and the contour of the cam is such that the shuttle and print elements will reverse their motion and will first accelerate to a constant velocity and then decelerate until the high rise point 1 on the cam reaches the position previously occupied by the low rise point 2 and in this position the shuttle and print blades will have been driven to the end of their travel toward the right. It can be seen that in similar fashion, further rotation of the cam presents low rise point 4 at which point the shuttle and print elements will have reversed motion and moved all the way toward the left and as high rise point 3 is presented the shuttle and print elements will again reverse motion and move all the way toward the right. Thus, as the cam continuously rotates, the shuttle and print elements will reciprocate back and forth with respect to the hammer elements. The shuttle does not reverse instantly. The hammer blades and dot print elements are equally spaced. For example, in the present embodiment there is an equal spacing of 0.300 inches between the centers of the dot print elements and between the centers of the hammer elements. The shuttle movement is 0.360 inches for total horizontal travel in each direction and the difference between 0.360 inches and 0.300 inches is to allow for the acceleration and deceleration of the shuttle motion. The normal constant velocity of the shuttle is 20 inches per second. When the last dot printing position is passed, the shuttle is decelerated to a 0 velocity and then accelerated back to its normal velocity in the opposite direction. the cam at the end of the shuttle provides this characteristic motion. As was previously mentioned, FIG. 2 is a view looking at the back of the print elements. FIG. 1 is a view looking at the front of the print elements and hammer elements in which case the cam mechanism will be at the right-hand end of the assembly and the cam would be rotating counter-clockwise. As a result, the direction of shuttle motion caused by the cam will be the reverse of that just described. Referring now to FIG. 3, there is shown an end view of the hammer magnet assembly and the print receiving structure. The hammer magnet assembly is fully shown and described in common assignee's copending application, Ser. No. 207,503, and will be but briefly described here. It should be mentioned at the outset that FIG. 3 shows one magnet assembly for one hammer element. There would be a plurality of identical assemblies arranged in a row, there being one assembly provided for each hammer element. The assembly includes a core means comprising base member 34 having outer pole piece 35, inner pole piece 36 and a support post 37 all of which are constructed of a magnetically permeable material. As was previously mentioned, the flexible hammer element 10 is fixed at one end to the surface of post 37 in the manner of an elastic cantilever beam by means of the clamping plate 11 and screws 12. The surface of post 37 is preferably slanted giving the hammer element 10 in outward print or actuated position when in its unflexed condition. The hammer element 10 is normally held in a retracted, spring loaded, non-print position, as shown, by magnetic forces produced by two permanent magents 38 and 39 coupled to the faces of the pole pieces 35 and 36. A focusing plate 40 of magnetically permeable material is applied over the outer magnet 38. There is provided a center pole piece 41 of magnetically permeable material which is surrounded by an electric coil 42. Coil 42 is connectable for energization to an external power source via connector pins 43. Center pole piece 41 is located in line with the hammer element position between pole pieces 35 and 36 and extends outwardly from base portion 34 to form an E-core structure. The center pole piece 41 terminates in a pole face covered with a cap 44, of non-magnetic residual material. The center pole piece 41 is made to extend beyond the respective surfaces of focusing plate 40 and inner permanent magnet 39 so that the cap makes contact with the hammer element when in its retracted position so as to maintain an air gap 45 between the focusing plate and hammer element and also between permanent magnet 39 and hammer element. The permanent magnets 38 and 39 are polarized in the same direction and are supported and magnetically coupled to the E-core structure made up of the base member 34, outer pole piece 35, inner pole piece 36 and the center pole piece 41. The magnetic surface structure produces dual closed magnetic holding circuits for holding the hammer element in spring loaded condition. In the outer magnetic holding circuit, magnetic flux from permanent magnet 38 passes through outer pole piece 35 through base member 34 and returns through center pole piece 41 across cap 44 into the extremity of the hammer element across gap 45 to focusing plate 40. In the second or inner magnetic holding circuit, magnetic flux from permanent magnet 39 passes through inner pole piece 36 and center pole piece 41 into the inner part of the hammer element and across gap 45. The center pole piece 41 provides a common return path for holding flux from both permanent magnets 38 and 39. Because flux from both magnets 38 and 39 passes in the same direction through a common path provided by the center pole piece 41, the selective release of the hammer element is expeditiously performed simply by energizing the coil 42 with current applied through connector pins 43 in the direction which produces a counter flux sufficient for reducing the magnetic holding force of both holding circuits on the flexible extremity of the hammer element. The hammer element is shown carrying the lower level impactor bar 16 which is in alignment with the lower level impact receiving bar 23 on the flexible print element 17. As was previously described, the print element is partially wrapped around and attached to the shuttle cylinder 20. The front of the print element carrier the dot print element 18 which protrudes through a hole 46 in a steel stripper plate 47 which extends across all of the print elements and has a hole in alignment with each dot print element 18. Stripper plate 47 has a wrapped around portion 48 which is suitably fastened around portion 19 which is then attached to the shuttle cylinder 20. The stripper plate 47 is provided to prevent an ink ribbon 49 from snagging and catching on the dot print elements 18. Ribbon 49 is moved across the print line by means of a conventional reel-to-reel drive, not shown. A thin steel clamp blade 50 is attached to a suitable frame member 51 and the flexible end portion of the blade extends partially between the ribbon 49 and the paper print medium 52 and serves to lightly clamp the paper against the platten 53 to prevent fluffing or rippling of the paper along the print line position. The platen 53 is indexed by suitable indexing means, not shown, to move the paper vertically one print line at a time. Referring to the block diagram shown in FIG. 5, the selective release of the hammer elements to effect printing is accomplished by an emiter 54 which senses the position of the print element shuttle 20. The emitter may comprise either an optical or magnetic emiter means. Emitter signals from the emitter are fed to suitable control logic 55 which determines the position to be printed. The output of the control logic is fed to a magnet coil driver circuit 56 which supplies current to the selected magnet coil 42 to release its associated hammer element. FIG. 4 is a front view similar to FIG. 1 and showing the position of the print elements when the shuttle reaches the end of its travel towards the left, as viewed from the paper plane, and is in position for reverse travel toward the right. Referring now more particularly to FIG. 6, there is shown a view looking down on the top of the lower level impactor bar 16 on the hammer element which is at the left end of the hammer element row and also the top of the corresponding lower level impact receiving bar 23 on the print element which is at the left end of the print element row. In one illustrative example of the arrangement of the present invention, all of the upper and lower level impactor bars have a width of 0.340 inches and all of the upper and lower level impact receiving bars have a width of 0.090 inches. All of the impact receiving bars travel a total distance of 0.360 inches in either direction. The impact receiving bar 23 travels 0.360 inches from its position shown in dotted lines to its stop position shown in solid lines. The 0.360 inches of travel may be considered in terms of including the impactor bar width of 0.340 inches plus 0.010 inches at each end of the bar. As shown, at the left end stop position there is 0.010 inches between the center line of the dot print element 18 and the end of the impactor bar and 0.035 inches of overlap between the end of the impactor bar and the end of the impact receiving bar. The same overlap condition occurs at the right end stop position. In all cases, the reciprocating impact receiving bars on the print elements never move horizontally off of its corresponding impactor bars on the hammer elements to preclude any nipping between the impactor and impact receiving bars. The 0.035 inches overlap provides sufficient overlap to assure that when the last print position is passed, that all print element impact receiving bars do not fall off the edge of the impactor bars on the corresponding hammer elements. This prevents crashing between the impactor and the impact receiving bars upon reversal of shuttle motion. And because the impactor bars on the hammer elements are arranged in an over-under fashion, no interaction will take place due to the actuation of adjacent hammer elements and also good impact is provided at the last dot printing position because the hammer element impactor bar always extends beyond the last dot position to provide the required force for impact. FIG. 6 also shows a view looking down on the top edge of the print paper 52. In one application of the present invention, a print zone having a width of 0.300 inches is provided for each hammer position. There are 5 print positions for each 0.100 inches of the print zone making 15 print positions for the zone. In the case of a 45 hammer unit, for example, this results in 135 character positions and 675 dot positions across 13.5 inches on the paper. The last print position is indicated at 57 and when the print element 18 passes this position, the cam mechanism will decelerate the shuttle to 0 velocity. This also occurs when the shuttle travels all the way to the right. In some high speed printer applications where a larger number of hammer elements and print elements may be required, the width of the impactor bars and impact receiving bars could be decreased and the adjacent impact receiving bars arranged to partially overlap each other. It will be understood that the present invention is not limited to the specific velocity and dimensions described. These factors may be varied to meet the requirements of different printing application. While the invention has been particularly shown and described with reference to a preferred embodiment thereof, 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.
A dot matrix printer is provided which has a row of hammer elements having horizontal impactor bars aligned at upper and lower levels and in partial overlapping relation with adjacent impactor bars. A row of print elements is also provided which alternately have horizontal upper and lower level non-overlapping impact receiving bars positioned opposite the hammer elements and in alignment with corresponding upper and lower impactor bars. Each print element has a dot print element on its opposite side and the row of print elements is mounted on a reciprocating shuttle. Means are provided for actuating the hammer elements whereby selected hammer impactor bars will impact the impact receiving bars to effect transverse deflection of the print elements to form dot impressions on a print medium.
1
BACKGROUND OF THE INVENTION The invention relates to a gas spring having speed regulation. Various forms of gas spring are known and may be used, for example, for raising or opening doors, such as hatchback doors, and lids in motor vehicle bodies for example, though they may be used in many other applications. In such springs, a cylinder is at least partially filled with gas which tends to expel a piston rod. It is desirable to be able to regulate the speed of movement of the piston rod so as to be able to achieve a desired speed of operation but with appropriate deceleration at the end of the travel of the piston rod. BRIEF SUMMARY OF THE INVENTION According to the invention, there is provided a gas spring, comprising a cylindrical body with a hollow interior containing a fluid which at least partly includes gas under pressure, first piston means slidable within the interior and dividing the interior into a first chamber on one side of the first piston means and a second chamber on the opposite side of the piston means through which a piston rod carried by the first piston means passes and extends sealingly outwardly of the cylindrical body such that the gas pressure within the cylindrical body tends to move the piston rod outwardly of the cylindrical body, means defining a fluid passageway past the first piston means for allowing gas pressure to transfer from the second chamber to the first chamber at a predetermined controlled rate during a first part of the outward travel of the piston rod, the fluid passageway having an opening in a face of the first piston means in the second chamber, control means within the cylindrical body having a face into contact with which the said face of the piston means moves during a second part of the outward travel of the piston rod so as to close the opening except for a subsidiary passage of reduced and predetermined cross-section which is open to the fluid passageway and which is not closed off by the contact between the said faces, whereby to allow reduced speed of travel of the piston rod during the second part of its outward travel. According to the invention, there is further provided a gas spring, comprising a cylindrical body having a hollow interior, first piston means slidable within the cylindrical body between first and second ends thereof and dividing the cylindrical body into a first chamber and a second chamber, a piston rod attached to the first piston means and extending through the second chamber and sealingly outwardly of the cylindrical body through the second end thereof, the cylindrical body containing fluid which at least partly includes gas under pressure and which tends to move the piston rod in a direction outwardly of the cylindrical body, the first piston means including means defining a first fluid passageway connecting the first and second chambers to permit transfer of the fluid from the second chamber to the first chamber as the gas pressure moves the piston rod outwardly of the cylindrical body, second piston means mounted on and slidable relative to the piston rod in the second chamber and biassed away from the second end of the cylindrical body so as to divide the second chamber into first and second parts thereof which are interconnected through or around the second piston means, the first fluid passageway having an opening in a face of the first piston means which opens into the first part of the second chamber to allow relatively rapid transfer of fluid from the second chamber into the first chamber during an initial part of the outward movement of the piston rod, the effective cross-sectional area of this opening being reduced to a predetermined size when the said face of the first piston means comes into contact with the second piston means so as to reduce the rate of transfer of fluid from the second chamber to the first chamber during the second part of the outward movement of the piston rod, and valve means carried by the first piston means for opening a second fluid passageway when the piston rod moves inwardly of the cylindrical body to allow relatively free flow of fluid from the first chamber to the second chamber when the piston rod moves in the inward direction. DESCRIPTION OF THE DRAWINGS Gas springs embodying the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: FIG. 1 is a longitudinal section through one of the gas springs on the line I--I of FIG. 2; FIG. 2 is a section on the line II--II of FIG. 1; FIG. 3 is a section on the line III--III of FIG. 1; FIG. 4 shows the flow of fluid through a piston in the gas spring of FIG. 1 during outward movement of the piston rod; FIG. 5 corresponds to FIG. 4 but shows the flow of fluid during return movement of the piston rod; FIG. 6 is a section on the line VI--VI of FIG. 1; FIG. 7 diagrammatically shows the gas spring of FIG. 1 to a reduced scale having a certain proportion of gas and oil within it, and also shows a graph illustrating the speed of movement of the piston rod over different parts of its travel; FIGS. 8, 9 and 10 correspond to FIG. 7 but show different proportions of gas and oil in the gas spring and the correspondingly different speeds of movement; FIG. 11 is a longitudinal cross-section through another of the gas springs embodying the invention on the line XI--XI of FIG. 12; FIG. 12 is a section on the line XII--XII of FIG. 11; and FIG. 13 is a section on the line XIII--XIII of FIG. 11. DESCRIPTION OF PREFERRED EMBODIMENTS The gas spring of FIG. 1 comprises a cylinder 10 made of suitably strong material, such as metal. It is closed off at one end by an end plate 12 supporting a fixture 14. It is closed off at the other end by a sealing assembly indicated generally at 16. The sealing assembly comprises a guide 18, a seal 20 and an abutment member 22. A piston rod 24 slidably passes through the sealing assembly 16, the seal 20 providing a gas and liquid-tight seal around the periphery of the piston rod 24. The piston rod 24 carries a piston 26 which comprises a piston body 28 having a peripheral groove 30 in which is situated a sealing ring 32. The width of the groove 30 (that is, its dimension measured axially of the cylinder 10) is greater than the thickness (the cross-sectional diameter) of the sealing ring 32. The piston body 28 is provided with four passageways 34, 36, 38 and 40 (see FIG. 2 also) which extend from the end face 42 of the piston body into the groove 30. The face 42, however, has portions 44, 46 and 48 which are recessed, in an axial direction, with respect to the remainder of the face 42. An axially directed bore 50 extends from the face 42 to the opposite axial end of the piston body 28 where it opens into a labyrinthine passageway 52 (see FIG. 6). The passageway 52 is in fact formed by a zig-zag channel formed in the face 53 of the piston body 28, but this channel is closed off by a circular plate 54 which is held in position by a rivet 56 (FIG. 1). The passageway 52, closed off by the plate 54, leads to an open end 58 (FIG. 6) which is in turn in communication with a chamber 60 (FIG. 1) via the gap between the periphery of the plate 54 and the inner surface of the cylinder 10. The bore 50 is open at its end 50A in the face 42 of the piston body 28. In addition, a narrow radially directed channel 62 (see FIGS. 2 also) connects the open end of the bore 50 to a space 64 around the free end of the piston body 28. The gas spring also includes a second or damping piston 70. The piston 70 is freely slidable on the piston rod 24 and is urged to the position shown in FIG. 1 by a compression spring 72, one end of which is located in a recess in the abutment 22 and the other end of which is located in a recess in a piston 70. The piston 70 closely though not sealingly slides within the cylinder 10. It is provided with four (in this example) axially directed grooves 74 arranged around its periphery (see FIG. 3). During manufacture, the interior of the cylinder 10 is charged with gas under pressure and also with some oil. The oil is shown at 76. The amount of oil may be varied, as will be explained. In addition to the chamber 60, the cylinder also contains a chamber 78 positioned between the face 42 of the piston 26 and the adjacent face 79 of the damping piston 70, and a chamber 80 positioned between the damping piston 70 and the abutment 22. Chamber 78 is in communication with the space 64. Obviously, the relative sizes of the chambers will vary according to the positions of the pistons 26 and 70 as will be described. Chambers 60 and 78 are interconnected at least through the bore 50 and the labyrinthine passage 52, and the chambers 78 and 80 are connected through the grooves 74. The operation of the gas spring of FIG. 1 will now be considered. The gas pressure within the cylinder 10 exerts a force on the inner end of the piston rod 24, tending to move it in an outward direction, that is, the direction A. As the piston rod, and thus the piston 26, move in this direction, friction between the sealing ring 32 and the inside wall of the cylinder 10 forces the sealing ring into sealing contact with the surface 84 of the groove 30 as shown in FIG. 4. The arrows B in FIG. 4 show how the pressurised gas transfers from chamber 78 into chamber 60 during this movement, the gas being compelled to flow through the labyrinthine passage 52. The speed of movement of the piston rod is thus controlled by the dimensions of the labyrinthine passageway and can be designed to be appropriate to the particular application. During this transfer of gas pressure, corresponding transfer of gas from chamber 80 to chamber 78 (FIG. 1) takes place through the grooves 74 in the damping piston 70. As the piston 26 continues to move, its face 42 will come in contact with the face 79 of the damping piston 70. This contact will close off the end 50A of the bore 50. Now, gas pressure can only transfer from chamber 78 into chamber 60 through the narrow feed channel 62. The speed of movement is significantly reduced. Continued movement of the piston rod is thus now controlled principally by the dimensions of the narrow feed channel 62 and also by the characteristics of the spring 72 which becomes progressively compressed as the movement of the piston 26 drives the damping piston 70 towards the abutment 22. If the quantity of oil 76 in the cylinder 10 is sufficient, some of this oil will then transfer from chamber 80 into chamber 78, through the grooves 74 in the damping piston 70, and thence through narrow feed channel 62, bore 50 and the labyrinthine passage 52, into chamber 60, providing further speed reduction. Piston 26 then forces piston 70 into contact with the abutment 22, and further piston movement stops. Such controlled movement of the piston rod 24 in the direction of the arrow A may be used to open or raise a door or lid in a motor vehicle. The fixture 14 may be connected to the vehicle's body and the free end of the piston rod 24 may be connected to the door or lid. The presence of the damping piston 70 and its effect in closing off the end of the bore 50, so as to force the transferring gas (or liquid) to pass through the narrow feed channel 62, enables the speed of movement of the piston rod to be varied during its travel. In this way, for example, rapid initial movement can be obtained, followed by slower movement ending in a smooth rather than an abrupt stop. Return movement of the piston rod 24 (that is, movement in the direction opposite to the direction of the arrow A) is normally carried out by the application of manual closing force to the door or lid controlled by the gas spring. As shown in FIG. 5, the frictional force acting on the sealing ring 32 moves the sealing ring axially out of contact with the surface 84 and into contact with the surface 86 of the groove 30. Gas can now transfer substantially freely from chamber 60 into chamber 78 by passing around the periphery of the piston body 28, past the sealing ring 32 and thence through the bores 34, 36, 38 and 40. In addition, gas can also flow into the labyrinthine passageway 52 through its opening 58 and into chamber 78 through the bore 50. During at least the initial part of the return movement of the piston rod 24, the damping piston 70 will be in contact with the face 42 of the piston body 28 and will close off the end 50A of the bore 50. The returning gas flowing through bore 50 will thus be forced to pass along the narrow feed channel 62. In addition, the bores 34 and 40 will be closed off by their contact with the face 79 of the damping piston 70. However, this will not have any significant effect on the return speed of the piston rod 24, because sufficient connection between chambers 60 and 78 is provided through the bores 36 and 38. When the return movement of the piston rod 24 has become sufficient, the damping piston 70 will reach the limit of its travel (defined by the maximum length of the compression spring 72), and the piston 26 will then move away from the now-stationary damping piston 70. Continued gas transfer can now take place through the bores 34 and 40, as well as the bores 36 and 38, and through the now-open end 50A of the bore 50. FIGS. 7, 8, 9 and 10 show how the gas spring can be given different speed characteristics according to the proportions of gas and oil within it. FIG. 7 diagrammatically shows the gas spring of FIG. 1 and illustrates the case where the level of the oil 76 is less than the face 79 of the damping piston 70. The graph in FIG. 7 has a portion A showing a relatively rapid speed of outward movement of the piston rod 24 during the time for which the piston 26 is clear of the damping piston 70. Over a period shown by the curve B. the speed of piston rod movement is reduced because the face 42 of the piston body 28 has come into contact with the face 79 of the damping piston 70, thus closing off the end 50A of the through bore 50 as explained above. After further outward movement of the piston rod, the oil, instead of the gas, now starts to transfer from chamber 80 into chamber 78 and possibly through piston 28 into chamber 60. The speed is further reduced as shown by curve C, until the piston rod comes to rest at the point D. FIG. 8 shows the case where the oil fills the interior of the cylinder up to the level of the face 79 of the damping piston 70 when the latter is in its innermost position. Over the region indicated by the curve A in FIG. 8, the speed of outward movement of the piston rod 24 is relatively rapid (corresponding to the speed shown by curve A in FIG. 7), because the piston 26 is clear of the damping piston 70. However, when the face 42 of the piston 26 comes into contact with the face 79 of the damping piston 70, not only is the end 50A of the through bore 50 closed off, but continued movement of the piston rod requires transfer of oil, not gas, into chamber 60. The speed of outward movement of the piston rod is thus reduced as shown by curve B in FIG. 8, until the piston rod comes to rest at the point D. FIG. 9 illustrates the case where the level of oil 76 within the cylinder is above the face 79 of the damping piston 70 when it is in its innermost position. Curve A in FIG. 9 shows that the piston rod 24 moves outwardly at relatively high speed for a short time, while gas is transferred from chamber 78 to chamber 60, piston 26 being clear of piston 70. Curve B illustrates the reduced speed which occurs when the face 42 of the piston 26 comes below the level of the oil 76, the oil now flowing through the labyrinthine passage. When the face 42 of piston 26 comes into contact with face 79 of damping piston 70, the speed is now further reduced as shown by curve C, because the open end 50A of the through bore 50 is closed off, and the oil is forced to flow through the narrow feed passage 62. The piston rod comes to rest at point D when the damping piston 70 reaches the abutment 22. FIG. 10 shows the case where there is no oil within the cylinder 10. Curve A corresponds to relatively rapid speed of outward movement of the piston rod while the piston 26 is clear of the damping piston 70. When the face 42 of the piston 26 comes into contact with the face 79 of the piston 70, the speed is reduced as shown by curve B. The piston rod comes to rest at point D when the damping piston 70 comes into contact with the abutment 22. FIGS. 11,12 and 13 show a modified form of the gas spring of FIG. 1. Items in FIGS. 11,12 and 13, corresponding to those in the other Figures are correspondingly referenced. In the gas spring of FIGS. 11,12 and 13, the face 42 of the piston body 28 is not provided with the narrow radially directed feed channel 62. Instead, a similar radially directed narrow feed channel 96 is formed in the face 79 of the damping piston 70. As shown in FIG. 13, this feed channel 96 leads into a circular channel 98 which is radially positioned so as to be in communication with the open end 50A of the through bore 50 in piston 28 when the face 42 of the piston 28 is in contact with the face 79 of the damping piston 26. In addition, the end face 42 of piston body 28 is not provided with the recessed portions 44, 46 and 48 shown in FIG. 2. Instead, the end 79 of the damping piston 70 is provided with a recessed portion 100. It will be apparent that the operation of the gas spring of FIGS. 11,12 and 13 is the same as the gas spring shown in FIG. 1. In other words, the provision of the damping piston 11 and the narrow feed channel 96 enables the outward movement of the piston rod 24 to be controlled so as to be relatively rapid at the beginning of its travel, then reducing when the face 42 of piston body 28 comes into contact with face 79 of the damping piston 70.
A gas spring comprising a cylindrical body in which a main piston is slidable and carries a piston rod extending in sealed manner outwardly of the cylinder. The main piston includes a bore connecting with a labyrinthine passageway. The interior of the cylinder contains a fluid comprising gas under pressure and (optionally) some oil. The gas urges the piston rod outwardly of the cylinder. During the corresponding travel of the piston, the fluid transfers from one side of the piston to the other in a controlled manner through the bore and the passageway to allow relatively rapid travel. However, when the main piston comes into contact with a second piston, freely slidable on the piston rod and biassed towards the main piston by a compression spring, this contact closes off the end of the fluid passageway, and fluid can now only transfer through the main piston by passing through a narrow radial channel, thus reducing the speed of outward travel of the piston rod. During this further outward travel, the main piston drives the second piston towards an abutment against the force of the spring.
5
[0001] This application claims the benefit of U.S. Provisional Patent Application 61/847,093, filed on 17 Jul. 2013, and U.S. Provisional Patent Application 61/865,625, filed on 14 Aug. 2013, the specifications of which are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Embodiments of the invention generally relate to implantable biventricular heart therapy devices that detect ventricular tachycardia and fibrillation. [0004] 2. Description of the Related Art [0005] Typically, tachycardia identification units allow biventricular detection of tachyarrhythmias, such as ventricular tachycardias (VT) or fibrillations (VF). Generally, therapy device control may initiate suitable therapies based on the detection. [0006] A system known as an S-ICD system typically operates with a far-field channel for VT/VF identification. [0007] For example, a specific type of tachyarrhythmias is “dissimilar” ventricular tachycardias, in which different (beat or contraction) rates prevail in the right ventricle (RV) and in the left ventricle (LV). [0008] Generally, ICD systems available on the market operate exclusively with a right-ventricular VT/VF identification channel. The left-ventricular sensing signals are typically used only for the inhibition of unnecessary LV stimulation and for the recording of an intracardial electrocardiogram (IEGM), but not for VT/VF identification. Based on the observation that there are ventricular tachycardias that have a considerable frequency difference between the right and left ventricle over a considerable period of time, typically, in the event of just right-ventricular detection, there is a potential risk that patients having these dysrhythmias are not being cared for sufficiently. [0009] For example, with a much quicker VT/VF in the left ventricle with a moderate VT in the right ventricle, generally, there is a risk of a lethal appearance of the dysrhythmia, since the time it takes for effective defibrillation is considerably too long as a result of the underestimation only using right-ventricular sensing. [0010] Typically, purely biventricular sensing poses a risk that, for example in the event of a left-ventricular electrode (coronary sinus electrode) dislocated in the region of the atrium, an atrial fibrillation is incorrectly classified as left-ventricular fibrillation (left-VF) and thus leads to an inadequate therapy delivery. A dislocated right-ventricular electrode, generally, may cause a comparable effect. [0011] As such, typically, isolated left-ventricular tachyarrhythmias may be cited as particularly relevant, since they are not generally correctly detected and treated using existing right-ventricular systems. Analyses of biventricular IEGM recordings, generally, reveal a considerable proportion of dysrhythmias of this type. [0012] Known biventricular heart therapy devices are generally inadequate with respect to dissimilar ventricular tachycardias. In view of the above, there is a need for a biventricular heart therapy device, which is able to adequately respond to dissimilar ventricular tachycardias. BRIEF SUMMARY OF THE INVENTION [0013] One or more embodiments of the invention are related to an implantable biventricular heart therapy device having a therapy device control unit, which includes a tachycardia identification unit connected, at least indirectly, to a right-ventricular sensing electrode and a left-ventricular sensing electrode. In at least one embodiment of the invention, the right-ventricular sensing electrode and the left-ventricular sensing electrode feed at least one signal from the heart's right ventricle and at least one signal from the heart's left ventricle, respectively to the tachycardia identification unit. In one or more embodiments, the signals represent a course over time of electrical potentials in the heart. During operation, in one or more embodiments, the signals representing a course over time of electric potentials in the heart or signals derived therefrom are fed to the tachycardia identification unit. By way of at least one embodiment, the tachycardia identification unit may evaluate the signals fed thereto or the course over time thereof, and generate a tachyarrhythmia signal if the fed signal meets predefined criteria, for example frequency criteria with regard to specific signal features, such as detected R waves. Due to the output of a tachyarrhythmia signal, in one or more embodiments, the tachycardia identification unit may signal a (pathological) tachycardia or fibrillation. In at least one embodiment, the heart therapy device may include an implantable cardioverter-defibrillator (ICD). Embodiments of the invention are generally configured to respond adequately to dissimilar ventricular tachycardias. [0014] In one or more embodiments, the tachycardia identification unit may simultaneously evaluate the heart rate at the right-ventricular and at the left-ventricular sensing electrode to identify ventricular tachycardia. [0015] In at least one embodiment, the therapy device control may include a dislocation identification unit connected, at least indirectly, to the right-ventricular sensing electrode and the left-ventricular sensing electrode. As such, in one or more embodiments, during operation, the signals representing a course over time of electric potentials in the heart or signals derived therefrom are fed to the dislocation identification unit. In at least one embodiment, the dislocation identification unit may simultaneously evaluate the heart rate at the right-ventricular and the left-ventricular sensing electrodes, signal a right-ventricular or left-ventricular dislocation, and generate a corresponding dislocation signal whenever the dislocation identification unit senses a sudden rise in heart rate at the right-ventricular or left-ventricular electrode, without detecting a significant rhythm change at the left-ventricular or the right-ventricular electrode within a predefined and/or adjustable time window. In one or more embodiments the therapy device control unit, in the event of a signaled dislocation of the right-ventricular or the left-ventricular electrode, may ignore the rhythm information of the dislocated right-ventricular or left-ventricular sensing electrode, or electrode in question, during tachycardia detection. [0016] The left-ventricular and/or right-ventricular signals fed into the tachycardia identification unit and to the dislocation identification unit, in at least one embodiment of the invention, may be signals derived from the signals sensed by the respective electrodes, for example marker signals generated by corresponding right-ventricular/left-ventricular sensing units, when one or more of the right-ventricular sensing unit, the left-ventricular sensing unit, the right-ventricular sensing electrode and the left-ventricular sensing electrode detect right-ventricular or a left-ventricular chamber contraction, for example on the basis of a corresponding R-spike in the electrocardiogram. [0017] The heart therapy device, according to one or more embodiments the invention, ensures an adequate antitachycardia therapy for ICD patients, in which dissimilar ventricular VT/VF episodes occur, for example tachycardia dysrhythmias, that may progress at different speeds in the right ventricle and in the left ventricle. The heart therapy device, according to at least one embodiment the invention, may prevent an atrial fibrillation from accidentally being incorporated into the VT/VF detection via a dislocated ventricle electrode. [0018] One or more embodiments of the invention allow an adequate therapy in good time in patients having ventricular tachycardias of different speeds in both ventricles, without an inadequate therapy being delivered in the event of an electrode dislocation. In at least one embodiment, the heart therapy device enables the avoidance of incorrect detections in the event of a dislocated probe, or electrode, and simultaneous atrial fibrillation. [0019] During operation, the heart therapy device according to at least one embodiment of the invention, may include an implantable defibrillator having at least one right-ventricular electrode and at least one left-ventricular (preferably coronary sinus) electrode, wherein each electrode may be connected to a tachycardia identification unit. In one or more embodiments, the tachycardia identification unit may, to identify ventricular tachycardias, simultaneously evaluate the heart rate at the right-ventricular and at the left-ventricular electrode. In at least one embodiment, the right-ventricular and left-ventricular electrode, in each case, correspond to a sensing electrode pole for bipolar or unipolar sensing of electric potential courses in the myocardium of the respective ventricle. In one or more embodiments, the electrode poles, for example, may be part of a corresponding electrode line and may be connected via the electrode line to the heart therapy device. According to at least one embodiment, the dislocation identification unit allows the detection of a possible dislocation of one of the ventricular electrodes and may simultaneously evaluate the heart rate at the right-ventricular and the left-ventricular electrode. In one or more embodiments, the dislocation identification unit may signal a right-ventricular or left-ventricular dislocation whenever a sudden rise in heart rate is sensed at the right-ventricular or left-ventricular electrode, without detecting a considerable change in rhythm at the left-ventricular or right-ventricular electrode around the same time, such that, in the event of a signaled dislocation of one of the ventricular electrodes, the rhythm information of the dislocated electrode, or electrode in question, may be ignored for, or during, tachycardia detection. [0020] In one or more embodiments, the tachycardia identification unit, following a dislocation signal of the dislocation identification unit, may ignore a signal originating from a respective dislocated electrode, or electrode in question, for, or during, the tachycardia detection. In at least one embodiment, the signal originating from an electrode identified as being dislocated, may not be fed to the tachycardia identification unit. [0021] One or more embodiments of the invention include at least one atrial electrode, wherein the heart therapy device may only carry out the electrode dislocation check using the dislocation identification unit when an atrial fibrillation (AF) is sensed at the at least one atrial electrode. For example, in at least one embodiment, an AF identification unit that detects atrial fibrillations may be provided. In one or more embodiments, in the event of a detected atrial fibrillation, the AF identification unit may output an AF signal that may cause a deactivation of the dislocation identification unit. [0022] By way of at least one embodiment, the dislocation identification unit may use at least one criteria of the following criteria or a combination thereof, to identify, or signal, the left-ventricular dislocation identification: a maximum permissible anteriority of a left-ventricular contraction before a right-ventricular contraction, stability of A-RV conductor time (conductor time from the atrium to the right ventricle), a rate comparison between the atrium and heart's left ventricle, a left-ventricular stimulation stimulus threshold, and morphology of left-ventricular R-waves before a preliminarily detected tachycardia with confirmed amplitudes impedances and stimulus thresholds. [0023] According to at least one embodiment, the heart therapy device may include a three-chamber device and a right-atrial electrode wherein the three-chamber device is connected to the right-atrial electrode, the right-ventricular electrode and the left-ventricular electrode. The tachycardia identification unit, in at least one embodiment, may perform a three-chamber discrimination algorithm, which is extended by comparison, in which, to classify the origin of a tachycardia, interval information of the left ventricle is and A-LV conductor times from the atrium to the left ventricle are recorded. [0024] By way of one or more embodiments, to discriminate between a physiological rise in heart rate (which leads to a sinus tachycardia) and a ventricular tachycardia of sudden onset, the tachycardia identification unit may extend an onset criterion (such as a sudden onset or a sudden rise in the heart rate within one heart cycle or just a rather low number of heart cycles) by the left-ventricular rhythm evaluation, and may signal a sinus tachycardia (by outputting a corresponding tachyarrhythmia signal) whenever there is no sudden rise in heart rate in the right ventricle and no sudden rise in heart rate in the left ventricle, and/or the interventricular conductor times (the A-LV conductor times and the A-RV conductor times) remain unchanged under consideration of a tolerance. [0025] In at least one embodiment, the tachycardia identification unit may apply a ventricular stability criterion to distinguish between a stable monomorphic ventricular tachycardia and a conducted atrial fibrillation in extended form, wherein a ventricular tachycardia (VT) is then only detected when the rhythm in both ventricles is classified as stable. [0026] The heart therapy device, in at least one embodiment, includes a therapy control, such that the heart therapy device may automatically switch the timer control over to the left-ventricular side (such that the times are controlled based on detected left-ventricular events) using the therapy device control unit. In one or more embodiment, using the timer control, the heart therapy device may control blank-out times necessary for the tachycardia detection, the left-ventricular signals are classified as suitable for the tachycardia detection, for example when no dislocation is identified. United Stated Patent Publication 2011/0082512 and European Patent 2 308 558, both of which are incorporated herein by reference, relating to a cardiac stimulator that may detect a stability parameter, include a timer control and a programmable automatic switch applicable to the present invention. Blank-out time, that is to say periods in which a respective sensing unit either cannot sense cardiac events or periods in which sensed cardiac events, in at least one embodiment, are ignored for the tachycardia identification. [0027] According to at least one embodiment, the tachycardia identification unit for the biventricular detection may include two separate detection counters for the right-ventricular and the left-ventricular signal, such as a right ventricle detection counter and a left ventricle detection counter. In at least one embodiment, when a predefined counter state is reached, one of the two counters, the right ventricle detection counter and the left ventricle detection counter triggers a corresponding detection and therefore a corresponding tachyarrhythmia signal. [0028] In one or more embodiments, the tachycardia identification unit for biventricular detection may include at least one single common detection counter for both the at least one right-ventricular signal and the at least one left-ventricular signal, wherein, in the event of, or during, a deviating interval time between the at least one right-ventricular signal and at least one the left-ventricular signal, tachycardia detection is always determined by the quicker ventricle, via the at least one single common detection counter. [0029] Regarding a termination criterion, used for the therapy device control unit to terminate an antitachycardia therapy (ATP, antitachycardia pacing), by way of at least one embodiment, the therapy device control unit may implement a termination criterion, which is then only considered to be met when measured interval times in both the right ventricle and in the left ventricle are greater than a predefined interval limit for the termination. [0030] In one or more embodiments, the therapy device control unit may consider the termination criterion to be met when the measured interval time, only in the right ventricle, is greater than a predefined interval limit for the termination. [0031] According to at least one embodiment, the heart therapy device may include a right-ventricular and left-ventricular undersense identification, for example, using a plausibility check of numbers of one or more of right-ventricular and left-ventricular intervals and atrial intervals. In one or more embodiments, the heart therapy device may switch over to a right-ventricular or left-ventricular detection whenever one of the ventricular electrodes has considerable undersensing, for example when one of the ventricular electrodes detects much fewer cardiac cycles than the other electrode(s), due in part to undetected cardiac events. [0032] In at least one embodiment, the tachycardia identification unit may be switched between a purely, or exclusively, right-ventricular tachycardia identification, in which only signals originating from a right-ventricular electrode and possibly additionally from an atrial electrode are evaluated for the tachycardia identification, and a biventricular tachycardia identification, in which signals also originating from a left-ventricular electrode are evaluated for the tachycardia identification. After implantation of the heart therapy device or a connected electrode line, in at least one embodiment, a purely, or exclusively, right-ventricular detection may thus always initially occur, until a stable electrode position in the left ventricle has been automatically determined by the heart therapy device, and the biventricular detection is then automatically activated. In at least one embodiment, the heart therapy device enables and may carry out automatic switchover between different tachycardia identification techniques. [0033] In at least one embodiment, one or more of the heart therapy device may include a shock electrode that delivers at least one defibrillation shock, wherein the heart therapy device and/or the therapy control unit may carry out an additional dislocation check of the left-ventricular sensing electrode as discussed above, or after each delivery of the at least one defibrillation shock. [0034] According to at least one embodiment, the dislocation identification unit may only detect a dislocation of a left-ventricular electrode, wherein the dislocation identification carried out by the dislocation identification unit relates only to a respective left-ventricular (coronary sinus) electrode, wherein the likelihood of a dislocation is greater. BRIEF DESCRIPTION OF THE DRAWINGS [0035] The above and other aspects, features and advantages of at least one embodiment of the invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: [0036] FIG. 1 : shows an example of a dissimilar ventricular tachyarrhythmia; [0037] FIG. 2 : shows a biventricular cardiac pacemaker, with a right-ventricular defibrillation shock coil, as an implantable cardiac stimulator; [0038] FIG. 3 : shows components of the implantable cardiac stimulator of FIG. 2 in the form of a simplified block diagram; [0039] FIG. 4 : shows a biventricular three-chamber cardiac pacemaker and implantable cardioverter-defibrillator (ICD) as an implantable cardiac stimulator; [0040] FIG. 5 : shows a flow diagram illustrating the dislocation identification; [0041] FIG. 6 : shows an example of biventricular detection; and [0042] FIG. 7 : shows a three-chamber discrimination algorithm. DETAILED DESCRIPTION OF THE INVENTION [0043] The following description is of the best mode presently contemplated for carrying out at least one embodiment of the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. [0044] FIG. 1 shows an example of a dissimilar ventricular tachyarrhythmia. As shown in FIG. 1 , the rhythm changes in the right ventricle (RV) from a stable VT over a short phase of VF to a slower VT 110 , and at the same time the rhythm in the LV channel changes at a later moment in time from a stable VT to a lasting VF, which is not sensed with a purely right-ventricular detection and may lead to an incorrect choice of therapy. [0045] FIG. 2 shows a biventricular cardiac pacemaker-defibrillator (ICD or CRT-D), having a right-ventricular defibrillation shock coil, as an implantable cardiac stimulation such as an implantable heart therapy device (heart stimulator) 10 , according to at least one embodiment of the invention. In at least one embodiment, the implantable heart therapy device 10 is connected via electrode lines 16 and 30 to stimulation electrodes 18 and 20 , and to sensing electrodes 32 and 34 , in the right and left ventricle of a heart respectively. In one or more embodiments, the heart therapy device may deliver stimulation pulses to the heart and record electric potentials from the heart. [0046] The electrode lines 16 and 30 , in at least one embodiment, are electrically connected via plug connections to contact sockets in a header (terminal housing) 11 of the heart stimulator 10 . In one or more embodiments, the electrode lines 16 and 30 may be connected to electronic components inside a hermetically tight metal housing 42 of the heart stimulator 10 . The electronic components, according to at least one embodiment, schematically illustrated hereinafter in FIG. 3 , may determine the operating principles of the heart stimulator 10 . [0047] In one or more embodiments, the electrode line 16 is a right-ventricular electrode line and has at its distal end a right-ventricular tip electrode pole RV Tip 18 , and in a direct or indirect vicinity thereof a right-ventricular ring electrode pole RV Ring 20 . In at least one embodiment, both electrode poles may be arranged in the apex of the right ventricle of the heart 12 . [0048] According to at least one embodiment, the electrode line 30 is a left-ventricular electrode line and includes at the distal end a bipolar stimulation and sensing electrode having a distal tip electrode pole LV Tip 34 , and in the direct or indirect vicinity thereof a left-ventricular ring electrode pole LV Ring 32 . In one or more embodiments, the left-ventricular electrode line 30 may be guided from the right atrium 26 of the heart 12 (illustrated in FIG. 4 ) via the coronary sinus into a lateral vein branching therefrom, also referred to as the coronary sinus electrode line or CS electrode line. [0049] In at least one embodiment, the right-ventricular electrode line 16 may include a right-ventricular shock coil RV Shock 38 , such as a large-area electrode pole that delivers defibrillation shocks. [0050] FIG. 3 shows components, such as key functional units, of the heart stimulator 10 . Also in FIG. 3 , additional components are illustrated via dashed lines, as may be provided in at least one embodiment of the invention. [0051] By way of one or more embodiments, as shown on the left hand side, electrical terminals for the various electrode poles 18 , 20 , 32 , 34 and 38 are illustrated. The shock electrode (shock coil) 38 , in at least one embodiment, is connected to a shock pulse generator 50 . In one or more embodiments, the shock pulse generator 50 may be connected to a control unit 54 , which controls the shock pulse generator 50 , as required, to generate and deliver a cardioversion or defibrillation shock. In at least one embodiment, the control unit 54 acts as a therapy device control unit 54 ′. The therapy device control unit 54 ′, in at least one embodiment of the invention, may be connected, for example, to the shock pulse generator 50 , to a right-ventricular stimulation unit 56 , and to a left-ventricular stimulation unit 64 . [0052] The control unit 54 , in at least one embodiment, may include a tachycardia identification unit 90 and a dislocation identification unit 92 . [0053] By way of one or more embodiments, the terminal for the right-ventricular tip electrode pole RV Tip, and the terminal for the right-ventricular ring electrode pole RV Ring, are each connected to both the right-ventricular stimulation unit 56 and to a right-ventricular sensing unit 58 . Both the right-ventricular stimulation unit 56 and the right-ventricular sensing unit 58 , in one or more embodiments, are each connected to the control unit 54 . [0054] According to at least one embodiment, the right-ventricular stimulation unit 56 , following a control signal of the control unit 54 , may generate a right-ventricular stimulation pulse and may deliver the right-ventricular stimulation pulse via the terminals for the right-ventricular ring electrode pole and the right-ventricular tip electrode pole. In one or more embodiments, the housing 42 of the heart stimulator 10 may form a neutral electrode, and the right-ventricular stimulation unit 56 may be connected to the terminal for the right-ventricular tip electrode pole RV Tip and to the housing 42 as another electrode to deliver a stimulation pulse. In at least one embodiment, a right-ventricular stimulation pulse differs from a defibrillation shock in that the stimulation pulse has a much lower pulse intensity, such that, by contrast to a defibrillation shock, it does not excite the entire heart tissue (myocardium) of an atrium in one attempt, but only the heart muscle cells in the direct vicinity of the right-ventricular tip electrode pole 18 . In one or more embodiments, the excitation then propagates further as a result of natural conduction over the entire ventricle and thus ensures a stimulated contraction of the ventricle. [0055] In at least one embodiment, the right-ventricular sensing unit 58 may first amplify, using an input amplifier, and then filter electric potentials applied across the terminal for the right-ventricular ring electrode pole RV Ring and the right-ventricular tip electrode pole RV Tip. By way of one or more embodiments, the right-ventricular sensing unit 58 may evaluate the course of the electric signals applied across its inputs in such a way that the right-ventricular sensing unit 58 automatically detects a natural (intrinsic) beat, such as an automatic contraction of the right ventricle. In at least one embodiment, the evaluation may be achieved, for example, by comparing the course of the signal applied across the inputs of the right-ventricular sensing unit 58 to a threshold value. In one or more embodiments, the largest amplitude of the signal is in the form of an R-spike, which is characteristic for a natural contraction of the right ventricle and which may be detected by comparison with a threshold value. In at least one embodiment, the right-ventricular sensing unit 58 , therefrom, may output a corresponding output signal (for example a marker signal), indicating a natural contraction of the right ventricle, to the control unit 54 , the tachycardia identification unit 90 and the dislocation identification unit 92 thereof. [0056] In one or more embodiments, the terminal for the left-ventricular tip electrode pole LV Tip and the terminal for the left-ventricular ring electrode pole LV Ring are also connected to the left-ventricular stimulation unit 64 and a left-ventricular sensing unit 66 . In at least one embodiment, the left-ventricular stimulation unit 64 and the left-ventricular sensing unit 66 may be connected to the control unit 54 . In one or more embodiments, the left-ventricular stimulation unit 64 and the left-ventricular sensing unit 66 may function similarly to the stimulation units 56 and 60 and sensing units 58 and 62 as described above. [0057] In at least one embodiment, the heart stimulator 10 may include an activity sensor 72 connected to the control unit 54 . The activity sensor 72 , in one or more embodiments, may detect a signal, for example a motion signal, dependent on the physical activity of a patient and may output a corresponding signal to the control unit 54 indicating the physical activity of the patient. As such, in at least one embodiment, the control unit 54 may adapt the timing of the stimulation pulse to the demand of the patient (haemodynamic demand). [0058] According to at least one embodiment, the heart stimulator 10 may include a memory unit 80 , connected to the control unit 54 , that stores signals generated or evaluated by the control unit 54 . In one or more embodiments, the memory unit 80 may store control programs for the control unit 54 in modifiable form. In at least one embodiment, the control unit 54 may be connected to a timer 82 . [0059] By way of one or more embodiments, the heart stimulator 10 may include at least one bidirectional telemetry interface 84 to transfer stored data from the implant 10 to an external device 100 and, vice versa, to also receive program settings and therapy commands from the external device 100 . [0060] FIG. 4 shows a biventricular three-chamber cardiac pacemaker and implantable cardioverter-defibrillator (ICD) as an implantable cardiac stimulator. As shown in FIG. 4 , the implantable cardiac stimulator 10 ′, in at least one embodiment, is connected via its terminal block 11 (header) to one or more of a right-ventricular electrode line 16 , a left-ventricular electrode line 30 and a right-atrial electrode line 14 . [0061] In one or more embodiments, the electrode lines may be implanted permanently in the heart 12 . In at least one embodiment, the right-ventricular electrode line 16 has at the distal end a bipolar stimulation and sensing electrode with a tip electrode pole RV Tip 18 and ring electrode pole RV Ring 20 . According to at least one embodiment, the electrode line may include a distal shock coil RV Coil 38 and additionally a proximal shock coil SVC Coil 40 . The distal shock coil RV Coil 38 , in at least one embodiment, may be arranged such that it is located in the right ventricle 28 . The proximal shock coil SVC Coil 40 , in at least one embodiment, may be located in the upper part of the right atrium 26 or in the superior vena cava (precava). [0062] By way of one or more embodiments, the electrode line 14 is an atrial electrode line and may include at the distal end a bipolar stimulation and sensing electrode, formed by a tip electrode pole RA Tip 22 and a ring electrode pole RA Ring 24 , implanted in the right atrium 26 . [0063] As shown in FIG. 4 , according to one or more embodiments, the left-ventricular electrode line 30 may include a left-ventricular shock coil 36 to deliver defibrillation shocks to the left ventricle. In at least one embodiment, the shock coil 36 may reach out from the left ventricle 44 as far as the left atrium 46 . In at least one embodiment, the implantable cardiac stimulator 10 ′ may include a second electrode, to deliver a shock, as the electrically active housing 42 of the implant 10 ′. [0064] As shown from FIG. 3 , in at least one embodiment of the invention, according to the components illustrated in a dotted manner, the terminal for the right-atrial tip electrode pole and the terminal for the right-atrial ring electrode pole may be connected to both a right-atrial stimulation unit 60 and to a right-atrial sensing unit 62 , which are each in turn connected to the control unit 54 . In one or more embodiments, the right-atrial stimulation unit 60 may generate stimulation pulses, of which the intensity is sufficient to excite the right-atrial myocardium. In at least one embodiment, the right-atrial stimulation pulses may have a pulse intensity different from the right-ventricular stimulation pulses. The right-atrial sensing unit 62 , in at least one embodiment, may detect a P-wave from the course of the differential signal applied across the inputs thereof, wherein the P-wave represents a natural (intrinsic) contraction of the right atrium. If the right-atrial sensing unit 62 detects a corresponding P-wave, in at least one embodiment of the invention, it generates an output signal and forwards the output signal to the control unit 54 , wherein the output signal represents a natural contraction of the right atrium. [0065] As shown in FIG. 3 , according to the components shown in a dotted manner, the left-ventricular shock coil 36 , as illustrated in FIG. 4 , may be connected to the shock generator 50 via a terminal LV-COIL and an electrode selection unit 52 . Using the electrode selection unit 52 , in one or more embodiments, the control unit 54 may select two or more electrodes (including the conductive housing 42 ), via which a shock is delivered. [0066] According to the heart therapy devices illustrated in FIGS. 2 to 4 , according to at least one embodiment of the invention, the tachycardic ventricular dysrhythmias may be classified simultaneously by the right-ventricular and the left-ventricular electrode line, primarily via the sensed heartbeats, wherein the quicker dysrhythmia primarily determines the therapy selection. At the same time, in at least one embodiment, a check is also performed for a possible dislocation of one of the ventricular electrodes in order to prevent inadequate therapy delivery. If such a dislocation is determined, in one or more embodiments, the relevant, dislocated or possibly dislocated, electrode is no longer used for the tachycardia detection. [0067] FIG. 5 shows a flow diagram illustrating the dislocation identification. In at least one embodiment, the dislocation identification is provided for the biventricular detection and may be carried out by the dislocation identification unit 92 . FIG. 5 shows an example of an LV dislocation identification, that is to say an identification of a dislocation of the left-ventricular electrode, according to at least one embodiment of the invention. [0068] Since the left-ventricular electrode line 30 (and therefore the left-ventricular electrode that surrounds the left-ventricular tip electrode pole LV Tip 34 and the left-ventricular ring electrode pole LV Ring 32 ), in one or more embodiments, may shift within the coronary vein in such a way that the electrode poles 32 and 34 are therefore located in the region of the atrium, it is not ruled out that an atrial tachycardia is incorrectly sensed as a left-ventricular tachycardia, and an inadequate therapy is initiated with biventricular detection (as described further below with reference to FIG. 6 ). [0069] In at least one embodiment, the dislocation identification unit 92 checks a possible dislocation of the left-ventricular electrode as follows: [0070] If the left-ventricular rate lies in a range of a VT/VF zone 310 , and if the right-ventricular rate lies in no zone or in a slower zone 320 , in one or more embodiments, the right-ventricular rate is checked as to whether it has changed significantly at the start of a respective left-ventricular tachycardia 330 . In at least one embodiment, if the right-ventricular rate remains largely unchanged, the heat therapy device thus detects a dislocation of the left-ventricular electrode 350 , and otherwise an actual ventricular arrhythmia 340 . [0071] According to at least one embodiment, to further improve the specificity of the dislocation identification, further electrodes and ECG discharge lines, such as a right-atrial electrode or a far-field ECG, may be used. In one or more embodiments, the criteria for LV dislocation identification may additionally include one or more of the following information for example: maximum anteriority of an LV sense before RV sense; stability check of the A-RV conductor time; comparison of the atrial frequency with the LV frequency or interval time; LV simulation stimulus threshold; LV-R wave morphology analysis; and, QRS far-field analysis (if the FF-QRS morphology remains the same, a dislocation is to be assumed when L-VF is indicated—specifically in the case of atrial fibrillation). [0078] FIG. 6 shows an example of biventricular detection. As shown in FIG. 6 , in at least one embodiment, biventricular detection includes counter logic and is represented as a marker chain. [0079] In one or more embodiments, the detection using the tachycardia identification unit may be performed via just one detection counter, which is incremented whenever an interval falls below the programmed tachycardia zone limit. In at least one embodiment, intervals sensed at the right ventricle and at the left ventricle are used to evaluate which ventricle is quicker using a count interval, wherein a right-ventricular interval is only permitted for the counting whenever it is shorter than or equal to the preceding left-ventricular interval, and a left-ventricular interval is only permitted for the counting whenever it is shorter than the preceding right-ventricular interval. [0080] According to at least one embodiment, the detection counter, implemented in the following example by the function cnt(RV), may increment a counter value by 1 whenever it is addressed: [0000] IF RV ( n )≦ LV ( n− 1) THEN cnt ( RV ); and, [0000] IF LV ( n )< RV ( n− 1) THEN cnt ( RV ); [0081] In one or more embodiments, only the “quicker” ventricle side is therefore always used for the tachycardia evaluation. As shown in FIG. 6 , in at least one embodiment, the interval markers permissible for the tachycardia evaluation are characterized by the following symbol: ↓. [0082] FIG. 7 shows a three-chamber discrimination algorithm with biventricular detection. According to at least one embodiment, the algorithm as shown in FIG. 7 demonstrates one of the possible implementation variants, since the biventricular discrimination may be integrated into any discrimination algorithms. In one more embodiments, the sensitivity and specificity of VT/SVT discrimination (the distinction between original ventricular tachycardias (VT) and supraventricular tachycardias (SVT)) may be improved. [0083] According to at least one embodiment, FIG. 7 illustrates the following symbols: RV: interval time, measured at the right-ventricular electrode; LV: interval time, measured at the left-ventricular electrode; A: interval time, measured at the atrial electrode; AV: atrio-ventricular conductor time (wherein, the algorithm may be extended by a distinction between the right-ventricular and left-ventricular conductor) VT: evaluation of the current ventricle excitation as the ventricular origin of tachycardia; and, SVT: evaluation of the current ventricle excitation as the supraventricular origin of tachycardia. [0090] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teaching. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention.
A heart therapy device having a right-ventricular electrode and a left-ventricular electrode connected to a tachycardia identification unit. The tachycardia identification unit identifies ventricular tachycardia and simultaneously evaluates the heart rate at the right-ventricular and left-ventricular electrodes. The ventricular electrodes each include an electrode line having a corresponding sensing electrode pole that senses electric potential courses in the myocardium of the respective ventricle. The heart therapy device includes a dislocation identification unit that detects a possible dislocation of one of the ventricular electrodes, simultaneously evaluates the heart rate at both ventricular electrodes, and signals a right-ventricular or left-ventricular dislocation when a sudden rise in heart rate is sensed at the right-ventricular or left-ventricular electrode, without detecting a considerable change in rhythm at the respective electrode. In the event of the dislocation of one of the ventricular electrodes, the rhythm information of the electrode in question is ignored for tachycardia detection.
0
This application is a continuation-in-part of copending application Ser. No. 06/564,435filed Dec. 21, 1983, abandoned. BACKGROUND OF THE INVENTION The invention relates to coatings to be used on ceramic fiber insulation, and more particularly to such coatings which are resistant to severe thermal shock and chemical attack. Ceramic fiber insulation is currently used as a high temperature lining for the interior walls and ceiling of furnaces and kilns. This insulation takes many forms, including blanket, felt, board, and modules with end strip and pleated configurations. Such materials have excellent insulating properties and are resistant to thernal shock, i.e. rapid changes in temperature. However, ceramic fiber insulation is fragile and susceptible to corrosive attack by chemicals such as compounds of sodium, boron, and iron. This insulation is also susceptible to the erosive effects of fine particulate matter entrained in high velocity gases typically present in many furnace environments. Fuels such as natural gas, oil and coal produce carbon dioxide, carbon monoxide, water, hydrogen, hydrocarbons, carbon particles, and entrained ash particles. To meet the need for protection of ceramic fiber insulation, various coatings have been developed. These coatings are typically blends of ground ceramic fiber and binders. U.S. Pat. No. 3,231,401 (Price et al) shows a combination of a ceramic fiber with an aqueous dispersion of colloidal inorganic oxide to produce a thermally shock resistant refractory coating or adhesive useful to about 2300° F. By making the coating out of the material to be coated, the problem of thermally matching coating to substrate (i.e. the surface of the underlying ceramic fiber insulation) is essentially eliminated but at great economic expense. A major disadvantage of ceramic fiber-based coatings is their high cost. Ceramic fiber if an expensive material, and these coatings are dense and therefore use a relatively great quantity of fibers. Additionally, these coatings generally fail to satisfactorily meet the requirements of a protective coating: good adhesion to the substrate and resistance to severe thermal shock combined with good chemical resistance. These coatings often crack and peel off the substrate, especially under thermal shock conditions. Many of the problems associated with the prior art are overcome to a substantial extent by the practice of the invention. SUMMARY OF THE INVENTION The present invention is directed to a fiber-free refractory composition for coating a ceramic fiber substrate consisting essentially by weight of 0 to 46.2% of an aluminosilicate mineral selected from the group consisting of kyanite, andalusite and sillimanite; 17.6 to 60.0% alumina; 2.9 to 5.7% colloidal silica; and 22.9 to 66.4% water. This mixture is characterized by good adhesion to substrate material, and excellent resistance to thermal shock and chemical attack through a wide range of firing temperatures up to 3000° F. The specific values of the components of the coating are selected to match the thermal expansion or shrinkage of the substrate. DESCRIPTION OF THE PREFERRED EMBODIMENTS Table 1 lists various values of the constituents of the invention which experimentally were found suitable to coat substrates of different thermal expansion or shrinkage characteristics. TABLE 1______________________________________Alumino- ColloidalTest silicate Alumina Silica Water CoefficientNo. % % % % of Expansion______________________________________ 5 0.0 51.0 3.1 45.9 Very Negative 6 0.0 30.7 2.9 66.4 Negative25 11.4 60.0 5.7 22.9 Neutral 4 15.9 31.8 4.8 47.5 Positive24 23.1 49.1 4.6 23.2 Positive 3 31.1 17.6 4.7 46.6 Very Positive23 34.6 37.6 4.7 23.1 Very Positive20 46.2 26.1 4.6 23.1 Very Positive______________________________________ The table is arranged in increasing levels of the aluminosilicate constituent. The coefficient of expansion terms of negative and positive refer to the thermal shrinkage and expansion behavior of the substrate. The experimental values given for the coating composition were determined for compatability with this behavior and adhesion to the substrate. A composition that has proved particularly successful in tests was applied to a ceramic fiber module fabricated from a combination of aluminosilicate and high-alumina fiber, and organic binders. One such ceramic fiber module is the Unifelt 3000 module manufactured by The Babcock & Wilcox Company, assignee of this invention. This module typically consists by weight of 71.7% alumina, 2.8% silica, and 5.5% loss-on-ignition. The aluminosilicate fiber is for example Kaowool ceramic fiber manufactured by The Babcock & Wilcox Company; the high alumina fiber is for example Saffil alumina fiber manufactured by Imperial Chemical Industries. A coating tailored to the above described module consists essentially by weight of 11.4% kyanite, 60.0% alumina, 5.7% colloidal silica, and 22.9% water (Test No. 25). The kyanite has a sieve size of minus 200 mesh, i.e. only material which passes through a 200 mesh screen is used. The alumina is a polycrystalline alpha alumina. In the preferred embodiment, 34.2% by weight of the total wet mixture is a minus 200, plus 325 mesh alumina grain, i.e. alumina that is smaller than 200 mesh and larger than 325 mesh. An example of such an alumina is T-61 alumina, a commercial alumina product manufactured by Alcoa. Likewise, in the preferred embodiment, 25.7% by weight of the total wet mixture is a minus 325 mesh alumina, such as A-2 alumina, a commercial alumina product manufactured by Alcoa. An example of a colloidal silica is Ludox HS-40, a colloidal silica dispersion manufactured by DuPont. This dispersion is an aqueous suspension of sodium stabilized silica particles of 40 weight percent solids. The colloidal silica acts an an inorganic binder which holds the other material together and functions as a bonding agent to insure a good bond between substrate and coating. The kyanite, alumina, and colloidal silica are mixed together. Water is then added to the mixture, and the resulting coating is applied to the fiber substrate by trowelling, spraying, or dripping. After air drying, the coated module is ready for use. A first test panel was coated with the coating described above and placed inside of a gas furnace. Upon firing, the furnace and panel were rapidly heated to 2500° F., after which the panel was removed from the furnace and exposed to a blast of cold air to shock the coating. The procedure was repeated on a 10 minute cycle. After 25 such cycles, the coating proved to be intact and had not cracked or flaked off the substrate. Prior art coatings tested under the same conditions failed after only two cycles. Thus the composition in accordance with the present invention has very good thermal shock resistance. A thickening agent may optionally be added to the composition, preferably about 0.2% by weight of the total wet mixture. Some examples are methycellulose, starch, gums, and clays. The thickener simply affects the consistency of the coating, and is neither critical to nor necessary for the invention. Suitable substitutes for the colloidal silica include ethyl silicate, such as tetraethyl orthosilicate, tetraethoxysilane, ethyl orthosilicate, silicate polymers, ethyl polysilicate, ethoxypolysiloxane; and colloidal alumina, such as aluminum oxide sol. The beneficial characteristics of the fiber-free coating of the present invention are especially unexpected in view of the different shrinkage and expansion characteristics of the aluminosilicate aggregate of the present invention to match and adhere to the substrate in comparison to the ceramic fiber of the prior art. While the composition described above as a preferred embodiment is tailored for a particular ceramic fiber module, modification of the constituents of the fiber-free coating allows for adoption of such coatings to other ceramic fiber modules having different expansion or shrinkage factors or different temperature ratings. As an example, for a module with a somewhat lower temperature rating (lower weight percent of high alumina ceramic fiber) than the module composition described above, the amount of kyanite present in the coating composition may be reduced to provide a composition thermally compatible with the substrate of the lower temperature module.
A fiber-free refractory coating composition consisting essentially of an aluminosilicate mineral selected from the group consisting of kyanite, andalusite, and sillimanite; alumina; colloidal silica; and water. This mixture is characterized by good adhesion to substrate material, and excellent resistance to thermal shock and chemical attack through a wide range of firing temperatures up to 3000° F.
8
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. application Ser. No. 09/531,543, filed Mar. 20, 2000 and now U.S. Pat. No. 6,296,470. BACKGROUND OF THE INVENTION The present invention relates to heat staking machines for joining parts together, and more particularly to a device for use on such a machine and having a radiant heat source to heat and thereby soften the part to be deformed. Heat staking is a process for permanently joining first and second parts at one or more discrete points marked by a plastic protrusion, hereinafter referred to as a stud, which extends upwardly from the first part and through an aperture in the second part when the second part is placed over the first part. The stud is sufficiently long to provide a volume of thermoplastic material which extends beyond the upper surface of the second part. Therefore, the plastic stud is heated until it is plastically deformable and then flattened and flared out with a metal punch to form a rivet-like head which locks the two parts together. It is possible to accomplish the heating and the deforming of the stud simultaneously by heating the punch prior to bringing it into contact with the stud, the punch transferring its heat to the stud to soften it as it is being shaped. In such an operation, the punch is typically resistance heated by electrical current. Heat staking machines operating in this manner are disclosed in U.S. Pat. Nos. 4,767,298 and 5,227,173. Another known heat staking technique is to heat the stud prior to it being contacted by the punch. In the past, this has been achieved by blowing hot air over the stud. U.S. Pat. No. 5,018,957 discloses a staking machine using electric heaters to generate the hot air and blowers to circulate the hot air over the stud. In some manufacturing operations, this pre-impact heating of the stud has been found to be advantageous in that it minimizes the amount of residual stress in the deformed stud after it has cooled. In the past, however, the apparatus necessary for the heating and circulation of air has resulted in a relatively large and mechanically complicated machine. Also, such a machine is relatively energy inefficient in that a large percentage of the heat generated is not transferred to the stud but rather is wasted. Moreover, the heat may be damaging to elements, such as printed circuits, on the parts being joined. It is therefore desirable to provide a heat staking machine that is energy efficient and that is simple and compact in construction, and which overcomes the problems associated with prior devices. SUMMARY OF THE INVENTION The present invention addresses and solves the above-mentioned problems and meets the enumerated objects and advantages, as well as others not enumerated, by providing an apparatus for heat staking in which the stud is heated by precisely focused infrared energy. The apparatus comprises a housing for holding the apparatus and for defining a cavity which can be placed in such a position as to substantially surround the stud. An infrared energy source is affixed to the housing with an energy directing means for directing the energy to the stud for the purpose of softening the stud. A deforming tool, hereinafter referred to as a punch, is mounted on a moveable carriage and designed for movement relative to the energy source toward and away from the stud. A preferred embodiment of the present invention hereinafter described utilizes at least one broadband incandescent lamp as the infrared energy source. This lamp is preferably a halogen lamp. The energy directing function is performed by one or more reflectors which are preferably gold plated to provide preferentially high reflectivity of infrared, thus increasing the percentage of total energy produced which reaches the stud. In a specific embodiment comprising primary and secondary reflectors, the secondary reflector is segmented to direct infrared energy to different areas of the stud, thus distributing the infrared energy over a larger area of the stud and reducing the time required to produce the softened state. In an alternate embodiment, the energy directing means includes a lens for focusing the energy into fiber optic cables. The fiber optic cables are arrayed around the stud, whereby the energy is directed from the cables onto the stud. BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the present invention will become apparent by reference to the following detailed description and drawings, in which: FIG. 1 is a side elevation view of a staking device according to a first embodiment of the invention with a staking punch in a retracted position; FIG. 2 is a cross-sectional view taken along line 2 — 2 of FIG. 1; FIG. 3 is a side-elevation of the heat staking device of FIG. 1 with the staking punch in the extended position to contact a workpiece; FIG. 4 a is a side elevation view of a secondary reflector in the heat staking device of FIGS. 1-3; FIG. 4 b is a side elevation view of a secondary reflector in the heat staking device of FIGS. 1-3 with a plurality of curved sections for directing the energy onto a stud; FIG. 5 is a view of the primary reflector/punch assembly of the heat staking device of FIGS. 1-3; FIG. 6 is a view of the body assembly portion of the heat staking device of FIGS. 1-3; FIG. 7 is a partial side view of a second embodiment of a heat staking device according to the present invention; FIG. 8 is a cross-section view taken along line 8 — 8 of FIG. 7; FIG. 9 is a partial side view of a heat staking device according to another embodiment of the invention; FIG. 10 is a bottom view of the heat staking device of FIG. 9; FIG. 11 is a side view of another embodiment of the present invention during the stud heating cycle; FIG. 12 is a side view of the heat staking device of FIG. 11 in a raised position; FIG. 13 is a side view of the heat staking apparatus of FIGS. 11-12 during the staking stroke; and FIG. 14 is a schematic view of a heat staking apparatus using fiber optic cables to focus the energy. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1-3, a heat staking device 10 according to the present invention is shown positioned above first and second workpieces 12 , 14 which are to be joined. As is well known in the heat staking art, a boss or stud 16 formed of a thermoplastic material such as ABS plastic projects upwardly from the first workpiece 12 , passes through a hole 18 formed in the second workpiece 14 and extends above the second workpiece 14 to provide a volume of deformable plastic material. The stud 16 is deformed into a fastener head utilizing heat staking device 10 in the manner to be described below to secure the first and second workpieces 12 , 14 together. The heat staking device 10 comprises a hollow cylindrical body 20 , an assembly 22 having a cylindrical portion which is received within the hollow interior of the body 20 and a parabolic portion which surrounds an incandescent lamp 40 and defines a primary parabolic reflector 38 . An end cap 24 attaches to the body 20 and defines a secondary reflector to receive radiation from the primary reflector 22 and directs it to the strut 16 where it is located within the end cap 24 . In essence, the primary reflector 38 captures radiation emitted radially from lamp 40 and directs it axially toward the end cap 24 . The secondary reflector defined by the end cap redirects the radiation radially inwardly toward a stud 16 protruding through the aperture in the end of cap 24 to heat and soften it. As shown in FIGS. 2 and 4 a, the body 20 and end cap 24 are circular in cross section. The lower end of end cap 24 has a polished interior surface 48 with an axis of symmetry 50 oriented vertically as shown in FIG. 4 a. A central aperture 52 is formed at the vertex of the cap 24 and is sized to allow stud 16 to protrude upwardly therethrough as seen in FIG. 1. A cylindrical rim 54 extends upwardly from secondary reflector 48 and has an annular shoulder 56 immediately adjacent the upper edge of secondary reflector 48 . As seen in FIGS. 1, 2 and 5 , the assembly 22 further comprises a punch 42 a having legs 42 b straddling the lamp 40 and connected to a carriage 42 for vertical sliding movement relative to the lamp 40 and the primary reflector 38 . As shown in FIG. 5, the carriage 42 moves between the retracted position, shown in solid lines, and the extended position shown in phantom lines. The punch head 42 is shaped in this case like an inverted cup to define the desired shape of the stud 16 after deformation. The punch head 42 a and legs 42 b are typically cast from a suitable metal and the contact surface may be cast, engraved or embossed to impart any desired design or logo to the finished plastic fastener formed from stud 16 . Punch legs 42 b are connected at the top by plate 42 c. The incandescent lamp 40 is preferably a 100 watt halogen lamp which produces substantial radiant energy in the infrared band, and is hereinafter referred to as an infrared lamp 40 . The adjustable carriage 42 is selectively driven toward and away from the stud 16 by a drive piston 28 a of an air cylinder 28 . The infrared lamp 40 projects through a round opening 44 at the vertex of primary reflector 38 (see FIG. 2 ). The body portion 20 which holds the reflector/punch assembly 22 and the end cap is shown in FIG. 6 . The body portion 20 comprises a generally cylindrical housing 26 , an air cylinder 28 mounted to an upper end of the housing and is supplied with air pressure through hoses 30 , a hollow receptacle 32 at a lower end of the housing, and electrical connectors 34 at an upper end of the receptacle 32 . Electrical power is supplied to connectors 34 through a power cord 36 . In an alternative embodiment, the secondary reflector 48 comprises a plurality of connected curved sections 49 with a central aperture 52 , as shown in FIG. 4 b. The secondary reflector 48 concentrates the light directed from a primary reflector 38 onto the stud 16 . The plurality of curved sections distributes the concentrated light over the portion of the stud 16 inserted into the cavity through the aperture 52 , rather than concentrating the light on a single smaller area of the stud 16 . This provides for a more rapid and more even distribution of energy to the portion of the stud 16 inserted into the cavity, and therefore a more rapid softening of the stud 16 . In another alternative, the secondary reflector 48 may comprise a single nonparabolic curved section for distributing the concentrated light over the portion of the stud 16 inserted into the cavity. To assemble the heat staking device 10 from the three components shown in FIGS. 4-6, the primary reflector/punch assembly 22 is inserted upwardly into receptacle 32 in the bottom of the body portion 20 so that the infrared lamp 40 makes contact with electrical connectors 34 and carriage butt plate 42 c contacts a drive piston 28 a of air cylinder 28 . Air cylinder piston 28 a preferably has a magnet 64 at its lower end which magnetically engages the butt plate 42 c of the carriage 42 so that when the piston 28 a returns to the retracted position it carries the carriage 42 along with it. This magnetic connection provides for superior field servicing of the heat staking device 10 , as there is no mechanical connection which must be disconnected before disassembling the heat staking device 10 . Although the magnetic connection is preferred, any means to create a detachable mechanical connection is contemplated to be within the scope of this invention. Alternatively, a spring (not shown) may be provided to return the punch 42 to the retracted position when air cylinder piston 28 a is withdrawn. The end cap 24 is then fitted over the lower end of the body portion 20 such that the outer rim of the primary reflector 38 is seated on shoulder 56 . The end cap 24 and body portion 20 may be secured together by a friction fit with a detent at the fully seated position, or rim 54 of the end cap 24 may have female threads formed on its inner circumference which mate with male threads formed on the lower end of the body portion 20 . An O-ring 58 may be provided around the body portion 20 to achieve a moisture-tight seal with the end cap 24 . As seen in FIG. 1, the workpieces 12 , 14 are supported on top of a lower platen 60 of a staking machine, and the heat staking device 10 is attached to an upper platen 62 of the staking machine. Upper and lower platens 60 , 62 are vertically movable relative to one another so that the heat staking device 10 is movable between a lowered position wherein stud 16 projects through aperture 52 in the end cap 24 (as shown in FIGS. 1 and 3) and a raised position (not shown) wherein the stud is withdrawn from the aperture 52 . In operation, a staking cycle begins when the workpieces 12 , 14 are positioned directly below the heat staking device 10 and the device is moved to a lowered position shown in FIG. 1 . The lamp 40 is energized and the radiation emitted thereby is directed downwardly by the primary reflector 38 , collected by the concave inner surface of the secondary reflector 48 , and focused radially inward onto the stud 16 . The lamp 40 is energized for a length of time sufficient to heat the stud 16 to a temperature at which it is plastically deformable. The required heating time depends upon the power output of the lamp 40 and the type and color of the plastic being heated. Using a 35 watt lamp 40 and white ABS plastic, for example, it has been found that it takes approximately 15 seconds to heat the stud 16 to 350-400° F., the temperature at which it may easily be formed. Darker colored plastic will heat up more quickly. In a preferred embodiment, the energy source is a 100 watt halogen lamp. The halogen lamp 40 produces energy across a broad band including the infrared, and heats the plastic to the desired temperature rapidly. Once the stud 16 is sufficiently softened, the lamp 40 is de-energized and the air cylinder 28 is actuated so that the drive piston 28 a is extended to drive the carriage 42 downwardly, urging the punch 42 a into contact with the stud 16 and deforming the stud as shown in FIG. 3 . The stud 16 is deformed into a fastener head to secure the first and second workpieces together. Punch 42 a preferably has a highly reflective surface finish so that it remains relatively cool. Accordingly, contact between the punch 42 a and the stud 16 causes the stud 16 to quickly cool and resolidify so that it retains its deformed shape when the air cylinder drive piston 28 a is retracted and the carriage 42 and punch 42 a return to their raised position. Rather than completely de-energizing the lamp 40 prior to actuation of the air cylinder 28 , it may be advantageous instead to reduce the electrical voltage supplied to the lamp 40 to a low level. This keeps the lamp 40 filament somewhat warm between heating cycles so that the lamp 40 can quickly return to the desired operating temperature when full power is reapplied. It should be noted that lamp 40 , primary reflector 38 , and secondary reflector 48 are oriented so that nearly all of the output of the lamp 40 is collected by the secondary reflector 48 and is concentrated onto the stud 16 . Accordingly, there is very little undesirable and wasteful heating of the structure of the heat staking device 10 or the surface of the first workpiece 12 surrounding the stud 16 . The concave inner surfaces of the primary reflector 38 and secondary reflector 48 are highly reflective of the wavelengths of infrared radiation emitted by lamp 40 . It has been found that a polished aluminum or stainless steel surface has desirable reflective properties. The secondary reflector 48 may be machined from a billet of aluminum or stainless steel, with the complex shape of the concave inner surface being formed by a computer numerically controlled milling machine. Preferably, a layer of gold is deposited on the surfaces of the primary reflector 38 and the secondary reflector 48 . The gold is deposited by dip-plating, electroplating, or by any means that deposits a thin layer of gold on the reflectors 38 , 48 surfaces. Preferably, the gold is deposited only on the surfaces of the reflectors 38 , 48 , but in an alternative, as an example, the entire end cap 24 may be dipped. Considerations for choosing the method of coating the reflectors 38 , 48 include balancing the cost of the method of coating the reflectors 38 , 48 with gold against the amount of gold used in the process of coating. Gold has the desirable property of reflecting virtually all of the energy in the infrared band thereby providing a very high efficiency for the transfer of infrared energy from the lamp 40 to the stud 16 . After punch 42 is returned to the retracted position, workpieces 12 , 14 are lowered relative to the staking device 10 (this may be achieved by raising upper platen or by lowering lower platen) to withdraw stud 16 from central aperture 52 , and another pair of workpieces to be joined are placed in the position shown in FIG. 1 . The heat/punch staking cycle is then repeated. Although FIGS. 1-3 depict a single staking device 10 , it is well known in the art to construct heat staking machines having a plurality of staking devices which are driven simultaneously, sometimes by a single air cylinder, so that multiple heat staked joints may be formed with a single stroke of the machine. In an alternative, rather than using a true parabolic primary reflector which is designed to direct its rays parallel to its central axis, it is possible to use a primary reflector having a convergent design. This type of reflector directs its rays inwardly toward a focal point, and this allows the secondary reflector 48 to be of smaller outer diameter than the primary reflector while still capturing all of the output of lamp 40 . In another embodiment of the invention shown in FIGS. 7 and 8, a heat staking device 110 comprises two primary reflectors 138 and two lamps 140 disposed in a side-by-side relationship above a secondary reflector 148 generally similar to that described in relation to the embodiment of FIGS. 1-6. The adjustable carriage 142 is disposed between the two primary reflector/lamp combinations and is movable along the central axis of the secondary reflector 148 during the staking stroke. The adjustable carriage 142 is a cylindrical shaft, rather than having two legs for straddling the centrally located lamp 40 in the embodiment shown in FIGS. 1-6. This multiple primary reflector configuration may be desirable in order to construct a staking press to meet certain space constraints, or where higher heat requirements require the use of two or more lamps. The interior surface of secondary reflector 148 may be specially designed to collect and focus the radiant energy from radiant heat sources located away from the main vertical axis of the secondary reflector. Any number of primary reflector/lamp assemblies may be disposed about the axis of adjustable carriage 142 , space permitting. When multiple lamps are used, and disposed around the axis of the adjustable carriage 142 , the lamps may include the primary reflector in the lamp unit. The use of a commercially available lamp and reflector unit provides for an energy source properly positioned within the reflector. This also provides for the convenient replacement of halogen lamps and reflectors. In another embodiment of the invention shown in FIGS. 9 and 10, a heat staking device 210 has first and second lamps 240 disposed in a side-by-side relationship within the concave interior of single reflector 248 . Reflector 248 has a central aperture 252 for receiving stud 16 , just as in the previously described embodiments, and a significant portion of the output from lamps 240 is captured and focused onto the stud by the single reflector without the need for primary reflectors to initially direct their output downwardly. As in the embodiment of FIGS. 7 and 8, adjustable carriage 242 passes between the lamps 240 during the staking stroke. Any number of lamps 240 may be used in this embodiment and spaced around the central axis of reflector 248 and adjustable carriage 242 . In another embodiment of the invention depicted in FIGS. 11-13, a heat staking device 310 has a primary reflector 338 , a radiant energy source 340 disposed within the primary reflector, and a secondary reflector 348 disposed below the primary reflector 338 to collect and focus energy from the source onto a stud 16 . A punch 342 a is disposed on an arm 343 pivotingly mounted on the outside of the reflector assembly. An air cylinder 328 is connected to the reflector assembly and has a vertically oriented drive piston 328 a which is connected to the arm 343 . During the heating cycle of the staking operation, staking device 310 is in a lowered position relative to the workpieces 12 , 14 and air cylinder drive piston 328 a is retracted to rotate arm 343 and punch 342 a to a raised position wherein it is pivoted outwardly and upwardly as shown in FIG. 11 . After the stud 16 has been heated for a sufficient length of the time to soften it, the entire heat staking device 310 is raised upwardly with respect to the workpieces as shown in FIG. 12 . The air cylinder piston 328 a is then extended to rotate the arm 343 in a downward direction until punch 342 a is located directly below the secondary reflector 348 , blocking its central aperture 352 as shown in FIG. 13 . The heat staking device 310 is then moved downwardly to urge punch 342 a against the stud 16 and deform it, as shown in FIG. 13 . In an another alternative embodiment of the invention shown in FIG. 14, an air cylinder 28 drives a selectively adjustable carriage 42 toward and away from stud 16 in a manner generally similar to the first embodiment disclosed hereinabove. In this embodiment, the energy source, such as an infrared lamp 40 , is mounted in a housing 26 , and adjacent to the adjustable carriage 42 . The movement of the adjustable carriage 42 being selectively driven by the air cylinder 28 . The energy from the lamp 40 is directed toward a convergent lens 70 by a reflector 38 . The energy is then focused by the convergent lens 70 into a fiber optic cable 64 . The fiber optic cable 64 extends from the lens 70 and splits into a plurality of sub-cables 66 which have distal ends 68 . The distal ends 68 are arrayed around and directed at a region into which the stud 16 is positioned. Preferably, the distal ends 68 are arrayed evenly around the region that encompasses the circumference of the stud 16 . The energy travels along the cable 64 and is split among a plurality of sub-cables 66 , and exits the sub-cable ends 68 . Fiber optic cables are thin glass or plastic filaments which conduct light by internal refraction, and are well know in the art. The use of a heat lamp in a staking machine according to the present invention provides a heat source with nearly instant on/off control, thereby providing precise temperature control. The radiant heat source heats only the stud, thus achieving an overall efficiency of approximately 80%. Commercially available infrared lamps are relatively inexpensive and have lives on the order of 2000 hours, contributing further to the economic advantage of the invention over the prior art. The use of commercially available 100 watt lamps provide sufficient energy for most plastics, but when greater energy is needed larger wattage lamps can be used. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
An apparatus for heat staking utilizes an infrared lamp to direct radiant energy onto a plastic part to heat and so soften it prior to the staking punch impacting the part. The apparatus comprises an energy directing means for concentrating the infrared energy onto the part, and a moveable carriage for moving the punch toward and away from the part. One embodiment of the energy concentrating means is a reflector, wherein the reflector includes a central aperture for admission of the part, and wherein the reflector comprises different curved sections for concentrating the energy over the surface of the part. In an alternate embodiment, the energy directing means comprises fiber optic cables for directing the infrared energy to the surface of the part.
1
BACKGROUND OF THE INVENTION The selection of needles according to a desired pattern is conventional practice on circular knitting machines and various control systems have been devised for this purpose. All such systems to applicants' knowledge have the disadvantage of requiring that the machine be shut down to provide for a new pattern of needle selection or comprising complicated and expensive apparatus to effect the desired change in needle selection. SUMMARY OF THE INVENTION According to the invention, a removable stand member is provided having a plurality of seats to accommodate pins which may be selectively positioned to activate an associated pattern blade which in turn is moved in the path of desired jacks. In a practical embodiment, the pattern blades are normally urged to an inoperative position by spring means. The spring means is overcome through the appropriate placement of pins in a supporting stand to engage a desired blade and move it into the path of the jack butts. Each blade includes two cammed surfaces, one of which is higher than the other and either of which can be alternatively positioned in the path of the jack butts to provide greater variations in the height the jacks and their associated needles can be raised. The invention includes means for removably attaching stands containing a desired pin arrangement for the activation of a selected needle pattern and the simple means by which the stands can be attached and removed from the machine makes it possible to program the needle selection in an area remote from the knitting machine and to quickly change the needle selection by simply changing the stand containing the pins controlling the selection of needles. OBJECTS OF THE INVENTION An object of the invention is to provide an apparatus of simple construction which may be easily removed and installed on an operating knitting machine to vary the selection of needles as desired at each feed station. The set-up is economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood from the following description taken in connection with the accompanying drawings in which: FIG. 1 is a vertical sectional view of one feed of a multi-feed circular knitting machine, partially in elevation and showing one needle and its associated lifting mechanism in accordance with the invention; FIG. 2 is a vertical sectional view, mostly in elevation taken substantially along the line II--II in FIG. 1 which coincides with the needle groove illustrated in FIG. 1; FIG. 3 is a vertical sectional view taken substantially along the line III--III in FIG. 1 and mostly in elevation; FIG. 4 is an enlarged sectional plan view taken substantially along the line IV--IV in FIG. 1; FIG. 5 is an enlarged elevation of a pattern blade removed from the machine; FIG. 6 is an end view of the pattern blade looking in the direction of the arrows VI--VI in FIG. 5; and FIG. 7 is an enlarged detail view of the medial portion of FIG. 1 showing the associated lifting mechanism between the jack and needle. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, there is shown, in pertinent part, a conventional multi-feed circular knitting machine of the type particularly adapted for the knitting of ladies stockings and panty hose and which comprises a needle cylinder 1 and an annular stationary frame 3. The needle cylinder rotates relative to the frame in the illustrated embodiment, but the invention is equally applicable with that class of machine wherein the frame rotates relative to the cylinder. The needle cylinder has a plurality of vertically extending grooves within each of which is mounted a knitting needle, only one of which is indicated at 5. The machine also includes a like number of sinkers 7 which cooperate with the needle to form the knit stitches. A yarn guide 9 feeds the yarn to the needles at each of the feed stations, only one being indicated in the drawings. Each feed station includes a stitch cam which draws successive needles downwardly to their knockover or maximum draw position. The needles are raised at each feed station to any desired height, such as the inactive position or the clearing position, or to any other position above the knockover position by jacks assembled in the needle grooves of the cylinder 1 and responsive to actuation by conventional camming to directly contact its associated needle spaced immediately above the jack in their respective needle grooves to raise it to a predetermined height. According to the invention, auxiliary linkage is provided between the upper end of each jack and the lower end of its associated needle. The linkage comprises first and second levers (19 and 23) for each needle groove, the first levers 19 each being journaled in the needle cylinder and extending radially outwardly therefrom. The second levers 23 are journaled in the frame 3 and extend toward the needle cylinder for engagement with their respective first levers 19. More specifically, each of the first levers 19 are journaled in a circular recess 15 communicating with respective needle grooves at a position between the lower ends of their respective needles and the upper ends of their associated jacks. The circular recesses or seats 15 communicate with their corresponding needle grooves, and the walls of the grooves each have extensions or flanks 17 extending radially therefrom. Each lever 19 is positioned between a pair of flanks 17, and has a circular extension 19A of corresponding configuration with the circular recesses 15. With the extension 19A seated within its recess 15, the lever 19 extends radially between the extensions or projecting flanks 17. An annular rim 21 is engaged to the outer ends of the flanks 17 which extend radially from the needle cylinder 1 and the rim 21 is movable with the needle cylinder. The rim 21 has a circular recess or seat for the reception of the circular extension 23A on each of a plurality of levers 23 corresponding in number to the levers 19 and co-acting with the same to raise the needles an amplified amount in relation to the movement of the jack. Each lever 19 is in contact with its lever 23 through respective cam surfaces 19B and 23B which retain the pairs of levers 19 and 23 in their respective seats. The rim 21 is provided with an annular projection 21X and an annular member 221 is clamped on rim 21 by screws 321. Flanks 17 have annular projections 117 which overlap and are clamped between projections 21X and 221 by the screws 321. Each lever 19 is raised with the aid of the upper end 13A of the corresponding jack 13, which engages a point X a short distance radially upwardly from the seat 15 of the extension 19A. The upper end of the cam surface 19B contacts the lever 23 at the point Y which is located further from the seat 15 and the circular extension 19A than is the point X. The lever 23 contacts the lower end of its associated needle 5 at the point Z which is further from the extension 23A than is the point Y. It follows from the above that any elevation or lifting of a jack 13 causes a much higher elevation or lifting of its respective needle, owing to the amplification resulting from the interaction of the two levers 19 and 23 making contact at the points X, Y and Z in response to elevation of a jack. Consequently, it is possible to use a relatively low cam surface in the trajectory S1 of the jacks to cause the desired higher elevation of the trajectory S2 of the needles previously obtained by a direct contact of the needles by their respective jacks in the prior art. The use of a low profile in the trajectory S1 of the jack is beneficial in operating at higher speeds. The use of the auxiliary levers for lifting the needles is also advantageous in that it makes possible a circumferential reduction of the space required for the jack cams and yet results in the needles being elevated to the same height as in the conventional system. Of course, any decrease in the circumferential space requirements correspondingly increases the available space for yarn feed stations in a given circumference. Spaced around the annular frame 3, and in correspondence of the row of removable control butts of the jacks 13, small blocks 31 are located in radially adjustable position, there being one such block for each yarn feed station, and more specifically in correspondence of each lifting trajectory S1 and S2. In each block 31, through suitable racks 32A and 32B, there are formed tangentially positioned radial seats for the reception of a plurality of pattern blades 33, arranged to act on the jack butts. Each blade 33 has on its inner end a first cammed surface 33A and a second cammed surface 33B, the first cammed surface 33A being at a lower elevation than the second cammed surface 33B. The first cammed surface 33A acts on the jack butts when the blade 33 is advanced only partially in a centripetal direction to a first position, while the cammed surface 33B acts on the jack butts when the blade 33 is advanced centripetally to its fullest extent. Each blade 33 includes a rear leg 33C having a head on its free end which retains a compression spring 35 encircling the rear leg 33C and engagable with the rear rack 32B to urge its respective blade 33 in the centrifugal direction to a suitable stop comprising a bar 37 bearing against the rear rack 32B. Each blade 33 also includes at its rear a stepped profile comprising two step portions 33E and 33F. The step portion 33E defines the rear edge of a laterally extending projection which has a forward edge or stop 33G. A stand member 39 is removably supported at 40 on each block 31, and the stand members 39 may be quickly connected in place by vertically extending racks 41 and 43. The rack 41 has a lower end releasably confined by a roller stop 45 while the upper rack 43 is bifurcated at its upper end and is releasably retained by a washer 47 retained on a threaded stud 49 by a suitable locknut in an adjustable manner. A sprocket wheel 51 is journaled for engagement with the teeth of the racks 41,43 intermediate the roller wheel 45 and the threaded stud 49 and each of the racks 41 and 43 extend sufficiently beyond the sprocket wheel to be operatively engaged thereby. Rotation of the sprocket wheel 51 in a counter clockwise direction in FIG. 3 will retract the racks 41 and 43 inwardly of the upper and lower edges 39A and 39B of the stand 39. The stand 39 is dimensioned to fit between the roller 45 and the stud 49 when the racks 41, 43 are retracted. Thus, the stand 39 may be quickly positioned with the racks retracted, after which the sprocket wheel 51 may be rotated in the clockwise direction in FIG. 3 to project the racks 41, 43 outwardly beyond the edges 39A, 39B of stand 39. As explained, the roller 45 retains the rack 41 and the washer 47 and its associated nut retain the bifurcated upper end of rack 43. The two racks 41,43 are guided in their vertical movement within the stand 39. A cover 53 retains the rack 41,43 and the sprocket wheel 51 in the stand 39. Each stand 39 contains a plurality of vertically arranged holes on the inner surface, said holes being arranged in two staggered rows, indicated respectively at 57 and 59 in FIGS. 2 and 4 and located in correspondence of the steps 33E and 33F on the respective blades 33. The holes 57 and 59 provide seats for pins 61 which may be removably retained within their seats formed by the holes in the rows 57 and 59. The pins 61 are of equal length and are arranged in selected seats before applying a stand 39 to its block 31 to obtain predetermined positionings of the blades 33. For example, a pin 61 in a hole of the row 57 acts (after assembly of the stand) on the corresponding blade 33 by contacting the surface 33E and thus urging the blade 33 centripetally until the cammed surface 33B lifts the jacks to a relatively high position (FIG. 4). By way of further example, a pin 61 in a hole of the row 59 acts, upon assembly of the stand 39, on the corresponding blade by contacting the surface 33F and thus urging the blade 33 centripetally until only the stepped portion 33A contacts the jacks to raise them a relatively lesser height. The absence of a pin 61 results in the corresponding blade 33 not being advanced and thus remaining excluded. Assuming the desired number of pins 61 to be positioned as desired within the holes in rows 57 and 59 in a stand 39, and assuming the stand 39 to have been attached to its respective block 31, the pins 61 will instantly contact one of the stepped portions 33E or 33F. However, centripetal movement of the blades 33 contacted by the pins 61 may be prevented because the jacks are in a non-raised position or are not raised to a position coinciding to the selection conditions required by the particular arrangement of the pins 61 in the stand 39 which is assumed to have been attached to its respective block 31. In order to preposition the jacks to be receptive to the desired placement of the pins 61, a cam 63 is mounted on a manually rotatably shaft 65, the cam 63 being adjustable by rotation of shaft 65 to act on a lower butt 13B of the jacks 13 causing all of the jacks 13 to climb in correspondence of the centripetally projecting blades 33 through engagement with their respective cammed surfaces 33A or 33B. This prevents interference of the blades 33 with the butts 13C. Whereupon the shaft 65 is manually rotated through a passage 69 formed between the block 31 and the stand 39 to inactivate the cam 63 and permit needle selection by the blades 33. With the foregoing apparatus, it is easy to make a desired needle selection and it is easy to modify the needle selection according to the working requirements. It is possible, also, to arrange a set of stands 39 with the pins 61 located in the desired manner to provide the desired needle selection before removing from the knitting machine stands having pin placements for a different pattern of needle selection. Thus, the present invention provides an effective and efficient means of needle selection which may be readily changed with a minimum of down time. A preferred embodiment of the invention has been described, but without limitation; the scope of the invention being defined by the claims.
The invention relates to a control system for the selection of knitting needles in a multi-feed circular knitting machine with the aid of jacks and means for selectively activating and inactivating desired jacks. A removable stand having holes for the reception pins to actuate selected pattern braids is programmed with pins in accordance with desired jack manipulation and replaced.
3
CROSS REFERENCE TO RELATED APPLICATION This application claims the priority of Federal Republic of Germany Application No P3931074.4, filed Sep. 18th, 1989, the subject matter of which is incorporated herein by reference. BACKGROUND OF THE INVENTION This invention relates to the production of profiles, strips, tapes, plates and the like of a thermoplastic material with fillers which influence the characteristics of the plastic and which are added to the basic thermoplastic before shaping. German Offenlegungsschrift (Non-examined Published Application) No. 2,228,677 discloses a plastic to which various fillers are added before the plastic is shaped. Examples of the fillers are calcium carbonate, asbestos, clay, kaolin and talcum. A small quantity of glass fibers can also be added to the substance. There is a high filler content of at least 300 and more parts by weight per 100 parts by weight of plastic. The glass fiber percentages, on the other hand, vary between 0.2 and 5 weight percent with reference to the total substance. The plastic substances which use these fillers and additives exhibit excellent processing characteristics and very good physical and mechanical characteristics such as reduced brittleness and improved abrasion resistance. A plastic material, for example, polyvinyl chloride, enriched in the above-outlined manner can be processed into floor coverings. The drawback of such plastic materials, however, is that other fields of use are not available because of the high filler content. German Patent No. 3,623,795, to which corresponds U.S. Pat No. 4,826,638, discloses the use of a fraction of hardened particles of an elastomer material as an additive to unhardened elastomer material before the latter is hardened. Particle sizes from 0.1 to 1 mm of hardened particles of an elastomer material can be added in an order of magnitude from 5 to 60 parts per every 100 parts of the unhardened elastomer material. Articles of elastomer material produced from this mixture such as, for example, silicone rubber, have a definitely irregular surface. It is important in the manufacture of such products that exclusively hardened particles of a hardened elastomer material can be added to the unhardened elastomer material as the starting product. The hardened elastomer particles may be silicone or caoutchouc elastomers. Thermoplastics or other materials, such as polyesters and the like, are excluded from such treatment. German Offenlegungsschrift (Non-examined Published Application) No. 2,255,033 discloses a method of introducing color pigments into the surface of plastic particles. The color pigments, which have a significantly higher melting point than the plastic particles, are embedded into the surface of the plastic particles as it begins to melt. In a second process step, the substance of the plastic particles is completely melted with the color pigment embedded in its surface, resulting in a completely died-through melt. SUMMARY OF THE INVENTION It is an object of the invention to provide articles of thermoplastic materials and a method of producing articles of thermoplastic materials such that the articles exhibit a special configuration of their surfaces in addition to the mechanical and chemical properties required for processing and later use. This object and others which will become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, particles of a plastic material which does not melt in the melt stream are introduced as influencing fillers to the basic thermoplastic material as, for example, surface roughness influencing fillers. Such particles are present in a maximum percentage of about 15 weight percent and have a maximum particle size of about 0.7 mm. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a shaped thermoplastic material with fillers and a method for producing a shaped thermoplastic material with fillers. Particles of a plastic material which does not melt in the melt stream are added to the thermoplastic as fillers that influence the plastic's characteristics, for example, surface roughness influencing fillers. Since the particles are of a plastic material which does not melt in the melt stream, the melting temperature of the plastic material should be higher than the melting temperature of the thermoplastic material. The basic thermoplastic used in the invention may be polyvinyl chloride (PVC), acrylonitrile butadiene styrene terpolymer (ABS) or polypropylene (PP). Other matrix materials may be used insofar as they can be processed with the particles to be added. The particles for influencing the surface roughness may be, for example, polyterephthalate (polyester) particles. Such particles can be obtained, for example, in regular or irregular sizes from a polyester sheet. An ultra-thin layer of a metal--e.g aluminum--may be vapor-deposited on one or both sides of the polyester sheet. In this way, special effects can be produced on the surfaces of the manufactured end products by means of the particles that are visible on the outside. These effects may even be augmented in that before the particles are produced, the polyester sheet is covered with a lacquer coating which may be colored in any desired hue, in addition to the vapor-deposited metal layer. It is to be understood that the lacquer layer must be heat resistant to such an extent that the processing temperatures for the thermoplastic material will not denature the lacquer layer. The particles may be cut, for example, in regular shapes from a polyester sheet. Such regular particles of smaller or larger dimensions may be combined to form a particle mixture which is able to impart a special configuration to the surface of the product. In addition to the regular cutting of the particles in any desired dimensions and configurations, the particles may also be produced by grinding the starting product. The starting product composed, for example, of a polyester sheet may be ground at cold temperatures. The grinding may occur in ball mills or impact crushers in liquid nitrogen at, for example, -120° C. In these known grinding processes, the optimum particle sizes can be set so that only the desired particle fraction is produced along with a negligible amount of dust. According to the present invention, the optimum particle size lies between about 0.002 mm and 0.7 mm, preferably between about 0.01 mm and 0.2 mm. These particles are added in a preferred quantity ratio of about 0.1 to 8 weight percent to every 100 parts of the basic thermoplastic material. The basic thermoplastic material enriched in this way can be used to produce profiles, strips, tapes, plates, hoses, tubes and the like. They may be produced in an extrusion process, by injection molding, or by blow molding. In processing the basic thermoplastic material with the particles according to the invention, the flexibility inherent in the particles is particularly significant. The particles made of polyester have similar processing characteristics as the basic thermoplastic material and have no abrasive characteristics which would adversely affect the processing machines. Such abrasive characteristics would be present if the particles were composed, for example, of metal foils (such as aluminum) or quartz or the like. Although the addition of such particles would also affect the surface characteristics of the resulting products, the particles' sharp-edged faces embedded in the surface would be undesirable in many cases. In addition to the negative effect of such abrasive particles on the conveying regions of the processing machines, the end products would have poor surface characteristics so that the use of such particles is undesirable. In contrast, the polyester particles of the present invention do not have a negative effect on the processing machines. During transport in the processing machines, the particles disposed in the edge regions of the starting matrix remain without difficulty at the surfaces of the conveying means until they reach the shaping tools. At the shaping tools the particles retain their sliding characteristics until they leave the processing machines. Since the particles in the present invention do not bond with the melt stream of the thermoplastic material during processing, the particles lie embedded as foreign bodies in the cross section of the melt stream as well as at its boundary faces. In the cross section of the melt stream and in the cross section of the resulting finished product, the foreign bodies are fully surrounded by and enclosed in the matrix of the basic thermoplastic material. Due to the small quantity of particles as enclosed foreign bodies, they do not have a negative effect on the end products. The particles that eventually settle in the boundary regions contact the inner faces of the tools in the final phase of manufacture. These particles are more or less embedded in the matrix and, when manufactured in an extrusion process, create a special surface configuration of the end products upon leaving the tool gap. The particles embedded near the surface may give the surface the character of stone with the roughness of a stone surface, which is influenced by the size and quantity of the added particles. The characteristics of the end product can be further varied by using particles having different surface colors. The particles may be coated on one or both sides, for example, with a colored lacquer of stone colors such as gray, brown, green or red. These different colored particles may be mixed together and added to the starting matrix to produce a specific coloration of the surface and of the cross section of the end products. It is a significant characteristic of the end products produced according to the present invention that after manufacture they can be further mechanically worked. Since the special surface configuration of roughness and color design is present not only at the surface but also throughout the entire cross section of the end product, further mechanical working is possible. The cross-sectional regions exposed by such mechanical working have approximately the same characteristics as the surfaces produced during manufacture of the product. Thus, the finished product has optimum use since it can be processed further after manufacture without quality loss on the surface or on the externally disposed cross-sectional regions. In addition to extrusion, an injection molding process can be used in the present invention. However, since the final shaping of the products takes places in a static region in the injection molding process, rather than by a sliding movement along the tool surfaces, the particles are firmly pressed into the surface by the injection pressure so that the end products will have an almost smooth surface characteristic. The present invention's end products produced in an injection molding process have the appearance of a smooth, polished stone surface and may have the same color designs as extruded end products. End products produced in a blow-molding process have similar characteristics as the injection molded articles since once the two-part mold has been closed, the extruded semi-finished products are pressed against the surfaces of the closed mold halves by the application of internal blow pressure. Such articles, when finished, also have the appearance of a polished stone, at least on their exterior contours. Due to the addition of particles, the extruded products can have a maximum roughness depth of 50 μm on their surfaces, depending on the size and quantity of the added particles. The preferred roughness depth is between about 10 μm and 40 μm. The roughness may be changed by the number and surface configuration of the added particles in order to suit the intended use of the end product. The particles may also be produced from a duroplastic material. They may have a regular shape in the form of cut particles or an irregular shape. The irregular shape may be produced by grinding. Preferably, previously produced sheets are used as the starting materials for the production of the particles. These sheets may be colored throughout or by surface coating. The surface coloration may be made by lacquer coatings or the vapor-deposition of metal. Metal covered sheets may additionally have a transparent colored coating of lacquers to produce special optical characteristics. The particles cut out of such sheets may be cut in regular shapes, such as squares, hexagons, rectangles, or in the shape of stars or the like. The use of different sizes of such regularly shaped cut particles permits the creation of special optical characteristics in the end products. It is also feasible to irregularly comminute the sheets to thus obtain an irregular effect in the cross section and on the surfaces of the end products. The particles may be introduced directly into the mixture ready for processing or as color granules of increased concentration. Mixing the particles in the matrix may occur before the manufacturing step in a special mixing process, for example, by producing the granules. If dye concentrates are used, the mixing may also take place during processing of the basic thermoplastic material. The roughness depth of the end products extruded according to one embodiment of the invention is a genuine roughness depth that can be discerned by touch and has the corresponding surface unevenness. The unevenness differs from a stamped surface which always has a certain similarity in the stamped patterns and does not imitate stone surfaces with a genuine appearance. In order that those skilled in the art may better understand how the present invention may be practiced, the following examples are given only by way of illustration, and not by way of limitation. EXAMPLE 1 A polyvinylchloride (PVC) matrix was used as the starting material. This starting material was mixed with 4 weight percent of the particles. The particles were a mixture of particles of sizes 0.01 mm and 0.4 mm. The particles were cut types represented at 2 parts of 0.01 mm and 2 parts of 0.4 mm, respectively. The end product produced in an extrusion process had a roughness depth of about 40 μm. EXAMPLE 2 Again, a polyvinyl chloride (PVC) matrix was used as the starting material. This starting material was mixed with 1 weight percent particles. In each case, 0.5 parts of particles of the size 0.01 mm and 0.5 parts of particles of the size 0.4 mm were used in the particle mixture. The particles were of the cut type. A roughness depth of 15 μm was measured on the surfaces of the extruded end product. EXAMPLE 3 Acrylonitrile butadiene styrene terpolymer (ABS) as the starting matrix was mixed with a quantity of 3 parts of particles of the size 0.02 mm. The roughness depth of the extruded end product was approximately 35 μm. EXAMPLE 4 A starting matrix of polypropylene (PP) was mixed with 1.5 parts of particles of the size 0.02 mm. A roughness depth of about 30 μm was measured in the extruded end product. 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 method of making a shaped thermoplastic article includes the following steps: mixing plastic filler particles of a maximum size of 0.7 mm to a thermoplastic material in a maximum percentage of about 15 weight percent for affecting a surface roughness of the article; processing the mixture resulting from the mixing step to obtain the shaped thermoplastic article; and maintaining the temperature of the mixture during the performance of the mixing and processing steps at a level below the melting temperature of the plastic filler particles.
2
TECHNICAL FIELD [0001] This invention relates to modeling a logic design using functional block diagrams and to generating simulation code that corresponds to the logic design. BACKGROUND [0002] Logic designers typically model logic designs, which may include circuit elements such as flip-flops, registers, and logic gates, using block diagrams. Computer-aided design (CAD) systems may be used to generate such block diagrams electronically. Conventional CAD systems, however, do not provide the flexibility and types/extent of information desired by many logic designers. [0003] Moreover, models created using conventional CAD systems are often of little assistance when simulating the logic design. Heretofore, a logic designer had to make a separate “simulation” model of the logic design using a simulation code, such as Verilog and Very High-Level Design Language (VHDL). The simulation model can be cumbersome and difficult to understand, particularly for complex logic designs. DESCRIPTION OF THE DRAWINGS [0004] [0004]FIG. 1 is a flowchart showing a process for modeling a logic design using functional block diagrams and generating simulation code that corresponds to the logic design. [0005] [0005]FIG. 2 is a block diagram of a menu for selecting functional block diagrams for the logic design. [0006] [0006]FIG. 3 shows functional block diagrams that were selected from the menu. [0007] [0007]FIG. 4 shows the functional block diagrams of FIG. 3 interconnected using virtual wire. [0008] [0008]FIG. 5 is a block diagram of a computer system on which the process of FIG. 1 may be executed. DESCRIPTION [0009] Referring to FIG. 1, a process 10 is shown for modeling a logic design. Process 10 may be implemented using a computer program running on a computer or other type of programmable machine, as described in more detail below. [0010] In operation, process 10 displays ( 101 ) a menu, such as menu 12 shown in FIG. 2. Menu 12 includes options for use in creating a graphical representation of a logic design. These options correspond to functional block diagrams for various circuit elements, such as registers 14 , ports 16 , AND gates 18 , OR gates 20 , buffers 22 , multiplexers 24 (MUX), and so forth. Data, including computer code, that defines the functional block diagrams for these circuit elements is stored in a database. The data defines inputs and outputs of each functional block diagram, as well as the operation to be performed on the inputs by the functional block diagram to generate the outputs. In one embodiment, the functional block diagrams are software “objects”. By way of example, in the case of an “AND” gate, the data specifies that the functional block diagram includes N (N>1) inputs, one output, and the definition of an operation to be performed on the inputs to generate the output. In the case of state elements, such as registers and flip-flops, the inputs may include one or more clock signals. [0011] The options on menu 12 also include a combinational (COMBO) box option 26 . COMBO box option 26 provides an undefined functional block diagram for use in a logic design. The undefined functional block diagram may be defined by the user to simulate any circuit element or combination of circuit elements. The user may enter simulation code via a graphical user interface (GUI) (not shown) to define the functionality of an undefined functional block diagram. The simulation code may specify inputs, outputs and operations to be performed on the inputs to generate the outputs. Examples of simulation code that may be used include, but are not limited to, Verilog, C++ and VHDL. [0012] Process 10 receives ( 102 ) an input selection from menu 12 . That is, a designer selects one or more of the options from menu 12 . The selection is transmitted to process 10 , which retrieves ( 103 ), from the database, a functional block diagram that corresponds to the selection. For example, a designer may select register option 14 . In response, process retrieves a “register” functional block diagram from the database. If the designer selects COMBO box option 26 , process 10 retrieves an undefined functional block diagram from the database. The designer specifies the function of that block diagram using, e.g., simulation code. [0013] Process 10 creates ( 104 ) a graphical representation of a logic design using retrieved ( 103 ) functional block diagrams. That is, process 10 displays the retrieved functional block diagrams and the designer arranges the functional block diagrams to represent a logic design. Although the designer is moving the block diagrams by, e.g., dragging and dropping, process 10 arranges ( 104 a ) the block diagrams in the sense that their movement is executed and stored via process 10 . FIG. 3 shows functional block diagrams 30 that have been arranged prior to being interconnected. [0014] Once the functional block diagrams are arranged, process 10 interconnects ( 104 b ) the block diagrams using virtual wires. That is, the designer selects wire option 22 from menu 12 and connects the inputs and/or outputs thereof using the virtual wires. Process 10 stores the configuration of the logic design, including the virtual wire connections, in memory. FIG. 4 shows the functional block diagrams of FIG. 3 following interconnection. It is noted that process 10 may display the definitions (e.g., 34 , 36 and 38 ) of each input or output terminal, or not, as desired. [0015] If there are any problems with the interconnections ( 107 ), process 10 displays a visual indication of the problem(s) with the design. In this regard, process 10 automatically runs a diagnostic on the logic design to confirm that the logic design comports with a set of predefined rules specifying, e.g., proper connections between terminals on different functional block diagrams. Examples of connection problems include, but are not limited to, unterminated connections and outputs running into the wrong inputs (e.g., a logic gate output running into a clock terminal input). [0016] In this embodiment, process 10 illuminates the logic design in red if there is a problem. Other indicators may be provided instead of, or in addition, to, illuminating the logic design in red. For example, the indication may specify the nature of the problem in words or graphics and its location within the logic design. [0017] If there are any problems with the displayed logic design, process 10 returns to one of the previous blocks 101 , 102 , 103 , and 104 , where the problem may be corrected. [0018] Assuming that there are no problems with the design, or that the problems have been corrected, process 10 generates ( 105 ) simulation code for the design. In this embodiment, process 10 generates Verilog, VHDL, and/or C++ simulation code. However, the simulation code is not limited to generating only these two types of simulation code. [0019] Generally speaking, the designer may select, e.g., via a GUI (not shown), which simulation code (C++, VHDL, Verilog) process 10 will generate. The type of simulation desired may dictate the simulation code that process 10 will generate. [0020] Process 10 generates the simulation code knowing the functional block diagrams that make up the logic design, their inputs and outputs, and their interconnections. For each functional block diagram, process 10 generates appropriate simulation code and provides the appropriate inputs and outputs. Process 10 combines the generated simulation code for the various functional block diagrams into simulation code that defines the logic design. [0021] Once simulation code for the logic design has been generated ( 105 ), process 10 tests ( 106 ) the logic design. This may be done by propagating one or more states through the simulation code and determining if there is an error based on the state propagation. For example, process 10 may propagate a logical one (1), a logical zero (0), and/or an undefined (X) state through the simulation code. If the resulting output of the simulation code is not what is expected, process 10 will indicate to the logic designer that an error exists in the logic design. The designer may then go back and change the logic design, as desired. [0022] [0022]FIG. 5 shows a computer 40 on which process 10 may be executed. Computer 40 includes a processor 42 , a memory 44 , and a storage medium 46 (e.g., a hard disk) (see view 48 ). Storage medium 46 stores data 50 that defines a logic design, a database 52 that includes the functional block diagrams, simulation code 54 (e.g., C++, Verilog, VHDL) for each functional block diagram and for the resulting logic design, and machine-executable instructions 56 , which are executed by processor 42 out of memory 44 to perform process 10 . [0023] Process 10 , however, is not limited to use with the hardware and software of FIG. 5; it may find applicability in any computing or processing environment. Process 10 may be implemented in hardware, software, or a combination of the two. Process 10 may be implemented in one or more computer programs executing on programmable computers or other machines that each includes a processor, a storage medium readable by the processor (including volatile and nonvolatile memory and/or storage elements), at least one input device, and one or more output devices. Program code may be applied to data entered using an input device, such as a mouse or a keyboard, to perform process 10 . [0024] Each such program may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language. The language may be a compiled or an interpreted language. [0025] Each computer program may be stored on an article of manufacture, such as a storage medium or device (e.g., CD-ROM (compact disc read-only memory), hard disk, or magnetic diskette), that is readable by a general or special purpose programmable machine for configuring and operating the machine when the storage medium or device is read by the machine to perform process 10 . Process 10 may also be implemented as a machine-readable storage medium, configured with a computer program, where, upon execution, instructions in the program cause the machine to operate in accordance with process 10 . [0026] The invention is not limited to the specific embodiments set forth above. For example, process 10 is not limited to the types and content of displays described herein. Other displays and display contents may be used. Process 10 is not limited use with the simulation languages noted above, e.g., Verilog, VHDL, and C++. Process 10 also is not limited to the order of execution set forth in FIG. 1. That is, the blocks of process 10 may be executed in a different order than that shown to produce a desired result. [0027] Other embodiments not described herein are also within the scope of the following claims.
Modeling a logic design includes displaying a menu comprised of different types of functional block diagrams, receiving an input selecting one of the different types of functional block diagrams, retrieving a selected functional block diagram, and creating a graphical representation of a logic design using the selected functional block diagram. The graphical representation is created by interconnecting the selected functional block diagram with one or more other functional block diagrams to generate a model of a logic design and defining the selected functional block diagram using simulation code if the functional block diagram is undefined when retrieved.
6
BACKGROUND OF THE INVENTION [0001] This invention relates to a multipath noise reducer, an audio output circuit including a multipath noise reducer, and a frequency-modulation (FM) radio receiver including a multipath noise reducer. [0002] Radio receivers are afflicted by various types of electromagnetic noise. Radio broadcast receivers mounted in automobiles, for example, must contend with ignition noise and mirror noise, which are impulsive in character and are generally referred to as impulse noise. These so-called car radios also experience episodes of multipath noise due to reflection of radio waves from hills, high buildings, and other passing objects. Multipath noise occurs because the car radio antenna receives both a line-of-sight signal, coming directly from the transmitting antenna, and reflected signals, reflected from the passing objects. The reflected signals tend to be out of phase with the line-of-sight signal, causing the line-of-sight signal to be partly attenuated by the reflected signals. The resulting deterioration in quality of the audio output from a car radio is a familiar experience to automobile riders. [0003] Various methods of reducing noise are known. In an FM stereo car radio, one method is to detect the strength of the electric field received at the antenna, and take noise countermeasures when the field is weak. One countermeasure is to reduce the degree of stereo separation, or to switch completely from stereo to monaural operation. This countermeasure will be referred to below as stereo separation control. Another countermeasure is to attenuate or “cut” high-frequency components in the demodulated signal. This countermeasure will be referred to below as high-cut control. Both of these countermeasures improve the signal-to-noise (S/N) ratio during intervals when the electric field received at the antenna is weak. [0004] To reduce impulse noise, car radios may also include an impulse noise reducer that detects the onset of impulse noise and generates a gate signal having a predetermined length sufficient to cover the expected duration of the impulse noise. When the gate signal is active, the signal output by the car radio is held constant, effectively suppressing the noise. [0005] The gate pulse used in this type of impulse noise reducer is too short to mask multipath noise, the duration of which is typically much longer than the duration of impulse noise. The gate pulse could be lengthened to cover multipath noise intervals, but a long gate pulse would noticeably distort the audio output signal. Furthermore, the long gate pulse would be triggered by each short occurrence of impulse noise, resulting in much needless audio distortion during times when no noise was present. [0006] Another problem is that although the effects of multipath noise vary depending on signal reception conditions and the audio signal level, the gate pulse width is conventionally the same for all reception conditions and audio signal levels. Accordingly, regardless of how the gate pulse width is set, it will sometimes be too long, causing needless audio distortion, and will sometimes be too short, so that multipath noise is inadequately reduced. [0007] Further details of these problems will be given in the detailed description of the invention. SUMMARY OF THE INVENTION [0008] An object of this invention is to reduce multipath noise adequately, with minimal output distortion. [0009] The invented multipath noise reducer includes a signal state determiner determining a state of an input signal, a threshold generator generating a threshold value responsive to the resulting state information, a high-frequency signal extractor detecting high-frequency components of the input signal, a comparator unit comparing the resulting high-frequency signal with the threshold value, thereby generating a multipath noise detection signal, and a correction unit modifying the input signal responsive to the multipath noise detection signal and the state information. [0010] By comparing the high-frequency signal with a threshold value, the invented multipath noise reducer is able detect and remove individual multipath noise spikes, thereby removing bursts of multipath noise without distorting other parts of the input signal. [0011] By determining the threshold value adaptively, on the basis of the state information, and by modifying the input signal adaptively, again on the basis of the state information, the invented multipath noise reducer is able to reduce multipath noise adequately under all signal conditions, without unnecessary distortion. [0012] The multipath noise reducer preferably also includes an input smoothing unit that smoothes the input signal. The smoothed input signal is used when the input signal is modified, enabling the correction unit to reduce distortion in the corrected signal still further. [0013] In this case, the correction unit preferably includes a gate generator that generates a gate signal by expanding pulses in the multipath noise detection signal by an amount depending on the state information, and a replacement unit. The replacement unit latches the smoothed input signal during each expanded pulse in the gate signal, and replaces the input signal with the latched value for the duration of the expanded pulse. The length of the gate pulse is thereby tailored to signal conditions, and replacement of the input signal with possibly distorted values is avoided. [0014] The gate generator preferably expands the gate pulses by increasing amounts as the received field strength of the input signal decreases, so that as the effects of multipath noise worsen, more of the multipath noise is removed. [0015] The gate generator also preferably expands the gate pulses by increasing amounts as the audio signal level decreases, so that as multipath noise becomes more noticeable, more of the multipath noise is removed. [0016] The high-frequency signal extractor preferably includes a high-pass filter and an absolute-value calculation unit, which together generate a high-frequency signal suitable for comparison with a threshold value. [0017] The multipath high-pass filter preferably receives input from the absolute-value calculation unit, an arrangement that tends to shorten the intervals in which multipath noise is detected so that they match the actual multipath noise intervals more closely. [0018] The threshold generator preferably includes a high-frequency smoothing unit that smoothes the high-frequency signal, and an adaptive limiting unit that limits the smoothed high-frequency signal according to the state information. The threshold value can thereby be kept from becoming too large during episodes of multipath noise. [0019] The threshold generator may also include an amplitude limiter that limits variations of the high-frequency signal before the high-frequency signal is smoothed, so that the threshold value can be kept from becoming too large without the need for a long smoothing interval. [0020] The adaptive limiting unit preferably includes a parameter adjustment unit that selects a comparison value and a limit value responsive to the state information, and a limiting unit that reduces the high-frequency signal to the limit value when the high-frequency signal exceeds the comparison value. The threshold value can thereby be lowered during episodes of multipath noise, so as to be sure of detecting all of the multipath noise. [0021] The parameter adjustment unit preferably increases the comparison value as the received field strength of the input signal decreases, to avoid reducing the threshold value when multipath noise is absent. [0022] The invention also provides an audio output circuit including the invented multipath noise reducer. [0023] The invention furthermore provides an FM receiver including both the invented multipath noise reducer and an impulse noise reducer, the impulse noise reducer removing residual impulse noise from the corrected signal output by the multipath noise reducer. [0024] The invention moreover provides a method of reducing multipath noise, essentially as described above. The invented method is useful when the invention is practiced using digital signal-processing circuitry. BRIEF DESCRIPTION OF THE DRAWINGS [0025] In the attached drawings: [0026] [0026]FIG. 1 is a block diagram of an FM stereo radio receiver illustrating a first embodiment of the invention; [0027] [0027]FIGS. 2A and 2B illustrate a typical multipath noise waveform; [0028] [0028]FIGS. 3A to 3 E are waveform diagrams illustrating the operation of the multipath noise reducer in FIG. 1; [0029] [0029]FIGS. 4A to 4 C are waveform diagrams illustrating the operation of the comparator unit and gate generator in the multipath noise reducer; [0030] [0030]FIG. 5 is a block diagram illustrating one possible structure of the threshold generator in FIG. 1; [0031] [0031]FIGS. 6A to 6 D are waveform diagrams illustrating the operation of the limiting unit in FIG. 5; [0032] [0032]FIGS. 7A to 7 D are waveform diagrams illustrating the operation of the parameter adjustment unit in FIG. 5; [0033] [0033]FIG. 8 is a block diagram illustrating another possible structure of the threshold generator in FIG. 1; [0034] [0034]FIG. 9 is a block diagram illustrating the internal structure of the gate generator in FIG. 1; [0035] [0035]FIGS. 10A to 10 D are waveform diagrams illustrating the operation of the gate generator in FIG. 9; [0036] [0036]FIG. 11 is a block diagram of an FM stereo radio receiver illustrating a second embodiment of the invention; [0037] [0037]FIGS. 12A to 12 E are waveform diagrams illustrating the operation of the multipath noise reducer in FIG. 11; and [0038] [0038]FIG. 13 is a block diagram of a conventional FM stereo radio receiver. DETAILED DESCRIPTION OF THE INVENTION [0039] Embodiments of the invention will be described with reference to the attached drawings, following a description of a conventional FM stereo radio receiver with an impulse noise reducer. This description is relevant because the impulse noise reducer is also used in the embodiments of the invention. Like elements in different drawings will be indicated by like reference characters. [0040] Referring to FIG. 13, the conventional FM stereo radio receiver comprises an antenna 1 , a radio-frequency (RF) front-end circuit 2 , an intermediate-frequency amplifier (IF AMP) 3 , an FM detector (DET) 4 , an impulse noise reducer 6 , a stereo demodulator (DEMOD) 7 , a low-frequency amplifier (AMP) 8 , a pair of loudspeakers 9 , 10 , a stereo separation controller (SP CNTRL) 11 , and a high-cut controller (HC CNTRL) 12 . [0041] The RF front end 2 amplifies the radio-frequency signal received from the antenna 1 and down-converts the amplified RF signal to the intermediate frequency. The IF amplifier 3 amplifies the resulting IF signal, and outputs both the amplified IF signal and a signal-meter signal or S-meter signal. The S-meter signal indicates the field strength received at the antenna. The FM detector 4 demodulates the amplified IF signal to generate an FM composite signal. The impulse noise reducer 6 reduces impulse noise in the FM composite signal. The stereo demodulator 7 separates the FM composite signal into a left-channel signal and a right-channel signal. The low-frequency amplifier 8 amplifies these two signals for output to the loudspeakers 9 , 10 . The stereo separation controller 11 performs stereo separation control on the basis of the S-meter signal. The high-cut controller 12 performs high-cut control, also on the basis of the S-meter signal. [0042] The impulse noise reducer 6 comprises a buffer amplifier 6 a, a delay unit 6 b, a gate unit 6 c, a high-pass filter (HPF) 6 d that extracts high-frequency impulse noise from the output of the FM detector 4 , a noise detector (DET) 6 e, a gate pulse generator 6 f that generates a gate pulse of a predetermined duration or width on the time axis when noise is detected, an automatic gain control (AGC) circuit 6 g for the noise level, an output unit 6 h, and a memory unit 6 i that stores the immediately preceding output signal. When noise is not detected, the gate unit 6 c remains closed, and the FM composite signal output from the FM detector 4 propagates through the buffer amplifier 6 a, delay unit 6 b, gate unit 6 c, and output unit 6 h to the stereo demodulator 7 and memory unit 6 i. When noise is detected in the FM composite signal by the noise detector 6 e, a gate pulse of the predetermined width is output from the gate pulse generator 6 f, opening the gate unit 6 c. While the gate unit 6 c remains open, the output signal from the delay unit 6 b is blocked, and the signal stored in the memory unit 6 i just before noise was detected is output instead, so that the noise does not reach the stereo demodulator 7 . [0043] The impulse noise reducer 6 is designed primarily to reduce impulse noise, but when the FM composite signal includes multipath noise, the multipath noise is also detected, and is reduced to some extent. [0044] The waveform in FIG. 2A shows a typical episode of multipath noise in an FM composite signal. The waveform in FIG. 2B shows an enlargement of one multipath noise burst. Multipath noise comprises a series of spikes occurring at intervals equal to the FM composite subcarrier period. The enlarged burst, for example, includes ten such noise spikes, each having a positive component and a negative component. [0045] The gate pulse generated by the gate unit 6 c, if set to reduce ignition noise, for example, has a width equivalent to only the first few spikes in the waveform in FIG. 2B. Consequently, the impulse noise reducer 6 is inadequate to the task of rejecting multipath noise. If the gate pulse width in the impulse noise reducer 6 were to be increased to cover the longest bursts of multipath noise, however, then much valid information would be lost following shorter bursts of multipath noise, leading to noticeable distortion of the audio output signal. In the worst case, the audio output signal might completely disappear for a noticeable length of time. [0046] Valid information is also lost in the brief intervals between noise spikes in the multipath noise waveform. [0047] As a first embodiment of the invention, FIG. 1 shows an FM stereo radio receiver comprising an antenna 1 , an RF front end 2 , an IF amplifier 3 , an FM detector 4 , a multipath noise reducer 5 , an impulse noise reducer 6 , a stereo demodulator 7 , a low-frequency amplifier 8 , a pair of loudspeakers 9 , 10 , a stereo separation controller 11 , a high-cut controller 12 , and a signal state determiner 13 . The multipath noise reducer 5 comprises a high-pass filter (HPF) 5 a, an absolute-value calculation unit (ABS) 5 b, a comparator unit (COMP) 5 c, a threshold generator 5 d, a delay unit 5 e, a replacement unit 5 f, a gate generator 5 g, and a smoothing unit 5 h. [0048] The high-pass filter 5 a and absolute-value calculation unit 5 b constitute a high-frequency signal extractor 5 ab in which the output of the high-pass filter 5 a becomes the input of the absolute-value calculation unit 5 b. The gate generator 5 g and replacement unit 5 f constitute a correction unit. The multipath noise reducer 5 , impulse noise reducer 6 , stereo demodulator 7 , low-frequency amplifier 8 , stereo separation controller 11 , high-cut controller 12 , and signal state determiner 13 constitute an audio output circuit. [0049] The elements other than the multipath noise reducer 5 and signal state determiner 13 are similar to the corresponding elements in the conventional FM receiver in FIG. 13, so detailed descriptions will be omitted. The gate pulse width in the impulse noise reducer 6 is adjusted for the removal of impulse noise such as, for example, automobile ignition noise. [0050] The signal state determiner 13 and multipath noise reducer 5 may include either analog or digital circuit elements, or a combination of both. The signal state determiner 13 and multipath noise reducer 5 may also be implemented partly or entirely by software running on a computing device such as a digital signal processor. [0051] Next, the overall operation of the first embodiment will be described. [0052] An FM broadcast signal is received by the antenna 1 and processed by the RF front end 2 , IF amplifier 3 , and FM detector 4 as described above. The FM composite signal output by the FM detector 4 will be referred to below simply as a demodulated signal. The demodulated signal passes through the multipath noise reducer 5 , which reduces multipath noise, then through the impulse noise reducer 6 , which reduces impulse noise. After these two types of noise reduction, the demodulated signal is supplied to the stereo demodulator 7 . The stereo demodulator 7 , low-frequency amplifier 8 , stereo separation controller 11 , and high-cut controller 12 operate as in the conventional FM radio receiver. The amplified left-channel and right-channel audio signals are reproduced through the loudspeakers 9 , 10 . In addition, the S-meter signal from the IF amplifier 3 and the audio signals output from the stereo demodulator 7 are supplied to the signal state determiner 13 . The signal state determiner 13 determines the state of the signal as received at the antenna 1 and as output from the stereo demodulator 7 , recognizing both the received field strength and the audio signal level, and provides corresponding state information to the threshold generator 5 d and gate generator 5 g in the multipath noise reducer 5 . [0053] Next, the operation of the multipath noise reducer 5 will be described in more detail with reference to the waveforms in FIGS. 3A to 3 E and 4 A to 4 C. [0054] The waveform in FIG. 3A is the enlarged multipath noise waveform that was shown in FIG. 2B. The waveform in FIG. 3B is the corresponding output of the high-pass filter 5 a in the multipath noise reducer 5 . The cut-off frequency of the high-pass filter 5 a is set to detect the noise spikes, while flattening out the slower variations between the noise spikes. The signal output by the high-pass filter 5 a accordingly sits substantially at the ground level between noise spikes, and reverses between positive values in the rising parts of each noise spike and negative values in the falling parts of each noise spike. [0055] The absolute-value calculation unit 5 b rectifies the output of the high-pass filter 5 a by replacing negative values with positive values of like magnitude, as shown in FIG. 3C. Multipath noise can accordingly be detected by comparing the signal output by the absolute-value calculation unit 5 b with a threshold signal, indicated by the dotted line in this waveform (FIG. 3C). The comparison is performed by the comparator unit 5 c; the threshold signal is generated by the threshold generator 5 d. The comparison results are then modified by the gate generator 5 g to generate a gate signal, shown in the FIG. 3D. [0056] [0056]FIGS. 4A to 4 C illustrate the operation of the comparator unit 5 c and gate generator 5 g. The first waveform (FIG. 4A) illustrates a single noise spike occurring in a multipath noise burst. The next waveform (FIG. 4B) illustrates the output of the comparator unit 5 c, referred to below as the multipath noise detection signal. The noise spike is detected as a single pulse. The gate generator 5 g delays and enlarges this pulse, as indicated in the third waveform (FIG. 4C). The enlargements are shown with dotted lines because the degree of enlargement varies, depending on the state information received from the signal state determiner 13 . The delay D also depends on this state information, as will be described later. [0057] The threshold generator 5 d generates the threshold signal by smoothing and limiting the output of the absolute-value calculation unit 5 b. Accordingly, the threshold signal is not constant, but tracks variations in the average level of the absolute value of the high-frequency signal output by the high-frequency signal extractor 5 ab. The reason for using this type of threshold signal is that under adverse receiving conditions, as the field strength at the receiving antenna 1 deteriorates, so does the signal-to-noise (S/N) ratio of the demodulated signal, raising the base noise level or ‘noise floor’ and causing the high-frequency signal extractor 5 ab to generate an increasing level of output due to noise other than multipath noise. The threshold value used by the comparator unit 5 c must be high enough so that the comparator unit 5 c does not detect noise that is part of the general noise floor. [0058] The delay unit 5 e delays the demodulated signal for the length of time taken by the high-frequency signal extractor 5 ab, comparator unit 5 c, threshold generator 5 d, and gate generator 5 g to detect multipath noise therein and generate the gate signal. The resulting delayed demodulated signal is supplied to the replacement unit 5 f. [0059] The smoothing unit 5 h smoothes the demodulated signal, and supplies the smoothed signal to the replacement unit 5 f. The smoothing process involves a delay substantially equal to the delay imparted by the delay unit 5 e. A detailed description of the smoothing unit 5 h will be omitted, because a detailed description of a smoothing circuit in the threshold generator 5 d will be given later. [0060] The replacement unit 5 f operates as both a latch and a switch. When the gate signal output by the gate generator 5 g is at the low level, indicating that the delayed demodulated signal is free of multipath noise, the replacement unit 5 f passes the delayed demodulated signal received from the delay unit 5 e to the impulse noise reducer 6 . When the gate signal goes high, the replacement unit 5 f latches the current value of the smoothed demodulated signal received from the smoothing unit 5 h. While the gate signal remains high, the replacement unit outputs the latched value to the impulse noise reducer 6 , in place of the delayed demodulated signal. When the gate signal goes low again, the replacement unit 5 f resumes output of the delayed demodulated signal received from the delay unit 5 e. The signal output by the replacement unit 5 f will be referred to as the corrected output signal. [0061] The corrected output signal is illustrated by the waveform in FIG. 3E. During each of the gate pulses in the 3 D, the corrected output signal remains constant. For simplicity, the delay introduced by the gate generator 5 g is ignored in this waveform (FIG. 3E) and the preceding waveform (FIG. 3D). [0062] Each spike in the multipath noise is thereby replaced with a smoothed version of the preceding demodulated signal value. The reason for using a smoothed value, instead of the actual demodulated signal value preceding the spike, is that the part of the demodulated signal waveform immediately preceding each noise spike is somewhat distorted by the noise spike, so use of a value latched from this part of the waveform might lead to audio distortion. By replacing each noise spike with a smoothed value, the multipath noise reducer 5 is able to remove the noise spikes without risking such distortion. Moreover, by replacing only the noise spikes, and not the parts of the waveform between the noise spikes, the multipath noise reducer 5 is able to avoid loss of the audio signal even during relatively long episodes of multipath noise. [0063] Next, more detailed descriptions of several of the components of the multipath noise reducer 5 will be given. [0064] [0064]FIG. 5 shows a circuit that can be used as the threshold generator 5 d. The values received from the high-frequency signal extractor 5 ab are denoted x(n), n being a discrete time variable; x(n) will also be referred to as the n-th sample received from the high-frequency signal extractor 5 ab. The letter K denotes a positive constant that operates as a time constant. Roughly speaking, the threshold generator 5 d smoothes out variations lasting less than K samples in the output of the high-frequency signal extractor 5 ab. The letter L is a coefficient or gain by which the smoothed value is multiplied to raise the threshold value above the noise floor. L is set to produce a threshold value intermediate between the noise floor level and the typical noise level when multipath noise is present. [0065] The circuit in FIG. 5 comprises multipliers 5 d 1 , 5 d 4 , 5 d 5 , an adder 5 d 2 , a one-sample delay unit 5 d 3 , a limiting unit 5 d 6 , and a parameter adjustment unit 5 d 7 . Multiplier 5 d 1 multiplies the n-th received sample x(n) by 1/K. Adder 5 d 2 adds the outputs of multipliers 5 d 1 and 5 d 4 to obtain a smoothed signal y(n). Delay unit 5 d 3 delays the smoothed signal y(n) by one sample period and supplies the delayed signal y(n−1) to multiplier 5 d 4 . Multiplier 5 d 4 then multiplies the delayed signal y(n−1) by (K−1)/K. The smoothed signal y(n) is accordingly given by the following equation. y ( n )=(1/ K )· x ( n )+{( K− 1)/ K )}· y ( n− 1) [0066] Multipliers 5 d 1 , 5 d 4 , adder 5 d 2 , and delay unit 5 d 3 constitute a high-frequency smoothing unit. Multiplier 5 d 5 multiplies the smoothed signal y(n) by L and supplies the result to the limiting unit 5 d 6 . The limiting unit 5 d 6 compares the received signal L·y(n) with two values c 1 , c 2 supplied by the parameter adjustment unit 5 d 7 (c 1 <c 2 ), replaces L·y(n) with a smaller value r 1 if L·yn)exceeds c 1 , replaces L·y(n) with a still smaller value r 2 if L·y(n) exceeds c 2 , and thereby obtains the threshold signal t(n) supplied to the comparator unit 5 c. The values of r 1 and r 2 are also supplied by the parameter adjustment unit 5 d 7 . The threshold signal t(n) can be described by the following equations. t ( n )= L·y ( n [0067] when L·y(n)≦c 1 t ( n )= r 1 [0068] when c 1 <L·y(n)≦c 2 t ( n )= r 2 [0069] when c 2 <L·y(n) [0070] The parameter adjustment unit 5 d 7 selects c 1 , c 2 , r 1 , and r 2 on the basis of the state information (STT-INF) obtained from the signal state determiner 13 , indicating whether receiving conditions are good or bad. The limiting unit 5 d 6 and parameter adjustment unit 5 d 7 constitute an adaptive limiting unit 5 d 67 . [0071] [0071]FIGS. 6A to 6 D illustrate how the threshold value t(n) varies during periods when multipath noise is present and absent. The first waveform (FIG. 6A) is the signal x(n) received from the high-frequency signal extractor 5 ab during a certain interval, indicated schematically using vertical lines. Multipath noise begins about halfway through this interval. As is commonly the case, there is considerable variation in the height of the multipath noise spikes. [0072] The next waveform (FIG. 6B) is the smoothed waveform L·y(n) output from multiplier 5 d 5 . If this waveform were to be used directly as the threshold value, some of the smaller noise spikes in the multipath noise interval might be missed. [0073] The next waveform (FIG. 6C) shows the smoothed signal L·y(n) again, and the two comparison values (c 1 , c 2 ) supplied by the parameter adjustment unit 5 d 7 . The last waveform (FIG. 6D) shows the threshold signal t(n) output by the limiting unit 5 d 6 . During the multipath noise interval, the threshold value is reduced first to r 1 , then to r 2 , then again to r 1 . While the threshold value is limited to these relatively low values (r 1 , r 2 ), no noise spikes are missed. [0074] The parameter adjustment unit 5 d 7 raises the comparison values (c 1 , c 2 ) and limit values (r 1 , r 2 ) as receiving conditions deteriorate; that is, as the received field strength decreases. When receiving conditions improve, these values (c 1 , c 2 , r 1 , r 2 ) are lowered again. FIGS. 7A to 7 D show this process for two cases, in both of which multipath noise begins halfway through the illustrated interval. The first waveform (FIG. 7A) is the output of the high-frequency signal extractor 5 ab under good reception conditions, with a strong electric field received at the antenna 1 . The second waveform (FIG. 7B) shows the smoothed signal L·y(n) and the two comparison values c 1 , c 2 selected by the parameter adjustment unit 5 d 7 under these conditions. The third waveform (FIG. 7C) shows the output of the high-frequency signal extractor 5 ab under poor reception conditions, with a weak electric field. Under these conditions, the noise floor rises, as illustrated in the left part of the fourth waveform (FIG. 7D), and the parameter adjustment unit 5 d 7 increases the comparison values to higher values c 1 ′, c 2 ′. Under both strong and weak field conditions, the comparison values are well above the noise floor, but are low enough to limit the threshold value appropriately during multipath noise. [0075] If the circuit in FIG. 5 uses analog components, then the multipliers 5 d 1 , 5 d 4 , 5 d 5 are amplifiers with the indicated gain values, the adder 5 d 2 is a summing amplifier, the delay unit 5 d 3 is an analog delay line, and n is a continuous time variable. [0076] [0076]FIG. 8 shows another circuit that can be used as the threshold generator 5 d. This circuit is identical to the circuit in FIG. 5, with the addition of a limiter 5 d 8 on the input side of the first multiplier 5 d 1 . The limiter 5 d 8 compares the received sample value x(n) with the output of multiplier 5 d 4 ; that is, with the delayed smoothed signal y(n−1) multiplied by the quantity (K−1)/K. If x(n) differs greatly from the output of multiplier 5 d 4 , the limiter 5 d 8 limits x(n) so that the signal received by multiplier 5 d 1 does not differ from the output of multiplier 5 d 4 by more than a predetermined amount. [0077] The limiter 5 d 8 operates as a type of amplitude-swing limiter, limiting the range of variation of the threshold signal output by the threshold generator 5 d. Even during intervals of multipath noise, accordingly, the threshold value does not increase too rapidly, enabling an appropriate threshold signal to be obtained without the use of an extremely large value of K. The reduction in the necessary value of K in turn enables the threshold generator 5 d to track changes in the noise floor more accurately. [0078] [0078]FIG. 9 shows a circuit that can be used as the gate generator 5 g. The multipath noise detection signal d(n) received from the comparator unit 5 c is delayed by a variable amount in a delay unit 5 g 1 , then held for a variable length of time in an expansion unit 5 g 2 , and finally sent as a gate signal g(n) to the replacement unit 5 f. The state information (STT-INF) provided by the signal state determiner 13 is received by a parameter setting unit 5 g 3 , which controls the delay time applied in the delay unit 5 g 1 and the holding time applied in the expansion unit 5 g 2 . [0079] [0079]FIGS. 10A to 10 D illustrates the operation of the gate generating means 5 g in FIG. 9. The first waveform (FIG. 10A) shows the multipath noise detection signal output from the comparator unit 5 c, illustrating a single pulse corresponding to the detection of a single noise spike. [0080] The next waveform (FIG. 10B) shows the gate signal output from the gate generator 5 g to the replacement unit 5 f when the gate pulse is delayed but not expanded. In this case, the parameter setting unit 5 g 3 designates a delay D in the delay unit 5 g 1 , and a holding time of zero in the expansion unit 5 g 2 . The value of D is predetermined so that the delayed gate pulse is centered on the noise spike received by the replacement unit 5 f from delay unit 5 e. [0081] The next waveform (FIG. 10C) shows the gate signal when the pulse is expanded by one unit of time (e.g., one sampling period) both in front and in back. In this case, the parameter setting unit 5 g 3 shortens the delay time by one time unit (from D to D−1), and designates a holding time of two (1*2) time units for the expansion unit 5 g 2 . The expanded pulse is consequently centered at the same point as the non-expanded pulse in the preceding waveform (FIG. 10B). [0082] The last waveform (FIG. 10D) shows the gate signal when the pulse is expanded by w units of time both in front and in back, where w is an arbitrary quantity not exceeding D. In this case, the parameter setting unit 5 g 3 designates a delay of D minus w time units (D−w) in the delay unit 5 g 1 , and a holding time of two times w time units (w*2) in the expansion unit 5 g 2 . The expanded pulse is again centered at the same point as the non-expanded pulse. [0083] The gate generator 5 g thus outputs gate pulses that are expanded by varying amounts, depending on the state information received from the signal state determiner 13 , but are always centered on the corresponding noise spikes. [0084] As noted above, the signal state determiner 13 receives both the S-meter signal indicating the received field strength at the antenna 1 , and the audio signals output by the stereo demodulator b 7 . The signal state determiner 13 provides the parameter setting unit 5 g 3 with information indicating both the received field strength and the audio signal level. The parameter setting unit 5 g 3 increases the amount of expansion (w) as the received field strength decreases, because under weak field conditions, the effects of multipath noise become relatively greater, so more of the noise must be removed. The parameter setting unit 5 g 3 also increases the amount of expansion (w) as the audio level decreases, because as the audio output becomes more quiet, the effects of multipath noise become more noticeable. Conversely, when the audio level is high, the effects of multipath noise tend to be masked by the strong audio output, and it is more important to avoid unnecessary blocking of the audio signal than to remove all of the multipath noise. [0085] By replacing noise spikes with a smoothed version of the demodulated signal, and by adapting the operation of the threshold generator 5 d and gate generator 5 g to the reception conditions and the audio signal level, the first embodiment is able to reject multipath noise effectively without causing noticeable audio distortion. [0086] In a variation of the first embodiment, the positions of the impulse noise reducer 6 and stereo demodulator 7 are interchanged. The stereo demodulator 7 now receives the output of the multipath noise reducer 5 . The impulse noise reducer 6 receives the output of the stereo demodulator 7 , and removes impulse noise from the left- and right-channel audio signals. [0087] As a second embodiment of the invention, FIG. 11 shows an FM stereo radio receiver that differs from the first embodiment only in the internal configuration of the high-frequency signal extractor in the multipath noise reducer. The high-frequency signal extractor 50 ab in the multipath noise reducer 50 in the second embodiment has the same high-pass filter 5 a and absolute-value calculation unit 5 b as the multipath noise reducer 5 in the first embodiment, but connects them in the reverse order, the high-pass filter 5 a now following the absolute-value calculation unit 5 b. Accordingly, the output of the FM detector 4 is supplied to the absolute-value calculation unit 5 b, the output of the absolute-value calculation unit 5 b is supplied to the high-pass filter 5 a, and the output of the high-pass filter 5 a is supplied to the comparator unit 5 c and threshold generator 5 d. [0088] Referring once again to FIGS. 3A to 3 E, a typical noise spike in the demodulated signal (FIG. 3A) has a negative component followed by a positive component. It therefore has a falling transition followed by a rising transition, then by another falling transition. In the first embodiment, the high-pass filter 5 a converts the two falling transitions to negative values and the rising transition to positive values, producing a negative component followed by a positive component, then another negative component, as seen in the waveform in FIG. 3B. The absolute-value calculation unit 5 b then converts the two negative components to positive components, so that all three components are detected above the threshold value, as indicated in the waveform in FIG. 3C. [0089] Referring to FIGS. 12A to 12 E, in the second embodiment, the absolute-value calculation unit 5 b converts the negative component of each noise spike in the demodulated signal (FIG. 12A) to a positive component, as shown in the waveform in FIG. 12B, so that each noise spike has two positive components. Each noise spike therefore has a rising transition followed by a falling transition, then another rising transition, then another falling transition. The high-pass filter 5 a converts the two rising transitions to positive values, as indicated in the waveform in FIG. 12C, and the two falling transitions to negative values, which have been omitted from this waveform (FIG. 12C) because they automatically fall below the threshold value, which is indicted by the dotted line. [0090] In the second embodiment, accordingly, only the leading edges of the negative and positive components of each noise spike are detected. The gate pulses, shown in FIG. 12D, are narrower than in the first embodiment, which detected both leading and trailing edges. The signal output from the multipath noise reducer 50 , shown in FIG. 12E, therefore includes more of the actual waveform of the demodulated signal than in the first embodiment. The gate pulses in the second embodiment (FIG. 12D) represent the actual widths of the noise spikes more accurately. Thus in eliminating multipath noise, the second embodiment causes even less distortion of the audio output signal than does the first embodiment. [0091] Another advantage of the second embodiment is that the high-pass filter 5 a can have a simpler internal structure than in the first embodiment. To detect multipath noise spikes accurately, the high-pass filter 5 a in the first embodiment requires a sharp cut-off characteristic, to avoid spreading out the noise spikes. The high-pass filter 5 a in the second embodiment does not require such a sharp cut-off characteristic; more spreading of the noise spikes can be tolerated, because only leading edges are detected. Thus the high-pass filter 5 a can be less expensive and more compact in the second embodiment than in the first embodiment. [0092] The variations described in the first embodiment can also be applied in the second embodiment. [0093] Those skilled in the art will recognize that further variations of the embodiments described above are possible within the scope claimed below.
A multipath noise reducer detects and removes the individual noise spikes occurring in an interval of multipath noise, thereby reducing the multipath noise with relatively little distortion of the output signal. The threshold signal used to detect multipath noise is varied depending on reception conditions. The gate pulses indicating the presence of multipath noise spikes are preferably expanded by variable amounts, depending on both reception conditions and the signal level. Multipath noise spikes are preferably replaced by a smoothed signal. These provisions further reduce perceived distortion of the audio output signal.
7
FIELD OF THE INVENTION The present invention relates generally to vessel harvesting and in particular to an improvement over existing endoscopic vessel harvesting techniques and devices. BACKGROUND OF THE INVENTION Endoscopic harvesting of vessels is well known in the surgical field and has been the subject of a great deal of recent technological advancement. Typically, the harvesting of vessels is performed so that the vessels can then be used for procedures such as Cardio Artery Bypass Grafting (CABG). In this procedure the saphenous veins of the legs are harvested for subsequent use in the CABG surgery. Devices and methods for such vessel harvesting are well known and have been described in numerous publications including U.S. Pat. No. 5,667,480 issued Sep. 16, 1997 and U.S. Pat. No. 5,722,934 issued Mar. 3, 1998 to Knight et al, both of which are incorporated herein by their reference. The devices and methods of these patents are briefly described below. In the traditional harvesting devices, there is provided a hollow shaft connected to a concave headpiece located at the distal end of the shaft which provides a workspace. An endoscope is typically inserted in the shaft so that the surgeon may view workspace. The leading edge of the headpiece is used for dissecting the vessel from the surrounding tissue. The device may also have guide rails located on the underside of the device which allow for the entry of other devices such as dissectors, ligation tools, and cutting tools into the workspace. The traditional method for removal of a vessel section is as follows. Initially an incision is made and the vessel is located. Then, the vessel is dissected form the surrounding tissue using the leading edge of the headpiece of the device to separate the tissue from the vessel. At this time there is sufficient workspace created around the vessel so that other instruments can be inserted into the incision via the guide rails located on the underside of the device. These instruments include ligation tools for securing side branch vessels, a vessel dissector for performing a more complete dissection of the vessel, which is to be removed, and laproscopic scissors for the transection of both the side branch vessels and the vessel which is to be removed. Of the known devices and methods for removal of vessels there remains one constant problem. The problem is that to perform each an every one of the side branch ligation and transactions, extra tools must be inserted along the guide rails of the device through the original incision. Often times this means that to perform a single transection of a side branch vessel three tools must be inserted in succession into the body. The various tools include, a dissector to dissect the side branch from the surrounding tissue, a ligation tool to clamp the side branch vessel and the vessel to be removed, and a cutting tool to perform the transection. Additionally, the harvesting device remains in the body throughout the procedure. This requirement of inserting the tools in succession and exchanging one tool for another to perform each step of the operation requires extra time, this in turn can be a drain on the individual surgeons resources. Further, because of this increased amount of time, which the surgeon requires to perform the operation, the stress on the patient is increased. Minimization of patient stress is naturally a concern during any surgical procedure. Therefore, the elimination of some or all of the time extending tool exchanges would greatly benefit not only the patient but the surgeon as well. SUMMARY OF THE INVNETION The present invention is directed to solving the shortcomings of known vessel harvesting devices, by providing a superior vessel harvesting device, promoting efficient removal of vessels, and limiting the stress on patients. The objects of the present invention are the minimization of the tool exchanges, increased efficiency of operation, minimization of patient stress, and increased ease of the overall harvest operation. Further, the present invention pertains to a device having a means for capturing side branch vessels so that they may be ligated and transected. Accordingly a vessel harvesting device is provided. The endoscopic device comprises a shaft having a lumen for insertion of an endoscope therethrough, a headpiece defining a workspace and disposed at a distal end of the shaft, a handle disposed at a proximal end of the shaft, a plunger disposed at the distal end of the shaft and movable between a retracted and extended position, wherein in the extended position the plunger interacts with at least a portion of the headpiece to capture a vessel there between, an actuation means for moving the plunger between the retracted and extended positions, and a ligation means for cauterizing the vessel captured between the plunger and the portion of the headpiece. The vessel harvesting device preferably comprises a transection means for transecting the cauterized vessel, wherein the portion of the headpiece comprises a hook projecting into the workspace. The headpiece preferably comprises side projections extending from an edge of the headpiece and projecting towards the plunger of the headpiece, the side projections facilitating the positioning of the vessel for capture. The ligation means preferably comprises the plunger having at least two electrodes of opposite polarity separated by at least one dielectric layer, the electrodes being energized with RF energy to cauterize the captured vessel. The transection means preferably comprises the plunger having an extendable knife separated from each of the at least two electrodes by a dielectric layer, wherein the at least two electrodes comprises a first and second electrode and one of the first and second electrodes is a knife separated from the other electrode by at least one dielectric layer. The portion of the headpiece preferably comprises a slidable hook projecting into the workspace, movable from an extended to a retracted position, wherein the hook interacts with the plunger to capture the side branch when in the extended position. The vessel harvesting device further preferably comprises a control rod actuation means for moving the slidable hook between the extended and retracted positions, wherein the control rod actuation means comprises a flexible control rod operably connected to the slidable hook for sliding the slidable hook between the extended and retracted positions, the control rod having an extension stop which limits the travel of the slidable hook and also having a capturing means which prevents the slidable hook and the control rod from entering the workspace, and wherein the control rod is formed of a flexible material conforming to the shape of the headpiece while transitioning from the retracted to the extended position and maintaining its conformance with the headpiece when in the extended position. Also provided is a method of removing a vessel utilizing the above-described device. The method of harvesting a vessel comprising the steps of providing a vessel harvesting device comprising a shaft having a lumen for insertion of an endoscope therethrough, a transparent headpiece defining a workspace and disposed at a distal end of the shaft, a handle disposed at a proximal end of the shaft, a plunger disposed at the distal end of the shaft and movable between a retracted and extended position, wherein in the extended position the plunger interacts with at least a portion of the headpiece to capture a vessel therebetween, an actuation means for moving the plunger between the retracted and extended positions, a ligation means for cauterizing the side branch, and a transection means for transecting the cauterized side branch, locating a vessel to be harvested, making an incision to expose the vessel, inserting the vessel harvesting device into the patient through the incision, dissecting the vessel from the surrounding tissue with the vessel harvesting device to expose a side branch of the vessel, actuating the plunger in the distal direction to capture the side branch between the plunger and the portion of the headpiece, applying RF energy to cauterize the captured side branch, transecting the cauterized side branch using the transection means, ligating and transecting the vessel, and removing the vessel. The step of ligating the side branch preferably comprises applying RF energy to the side branch using first and second electrodes, wherein the first and second electrodes are of different polarity and are housed in the plunger. The step of transecting the side branch preferably comprises extending a knife housed in the plunger towards the distal end of the device. The step of capturing preferably comprises placing the headpiece over the side branch and extending the plunger in the distal direction to allow the side branch to be compressed between the plunger and the portion of the headpiece. The step of transecting the side branch preferably comprises advancing a knife housed in the lower jaw towards the distal end of the device subsequent to the ligation of the side branch vessel. The step of actuating preferably comprises extending a slidable hook in the distal direction prior to extension of the plunger. This use of the plunger and the ligation and transection means located therein limits the number of tools which must be inserted into the incision. Further, by having the ligation and transection means located in the plunger the procedure is more easily performed, and with a minimum of stress to the patient and in a decreased amount of time. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a perspective view of preferred implementation of an endoscopic vessel harvesting device of the present invention. FIG. 2 illustrates an enlarged front view of the headpiece of the endoscopic vessel harvesting device of FIG. 1 . FIG. 3 illustrates an enlarged side view of the headpiece of the endoscopic harvesting device of FIG. 1 FIG. 4 illustrates an enlarged bottom view of the headpiece of the endoscopic harvesting device of FIG. 1 . FIG. 5 illustrates an enlarged side view of a distal end of the headpiece for the endoscopic harvesting device of FIG. 1 in which a plunger is being extended. FIG. 6 illustrates an enlarged side view of a distal end of the headpiece for the endoscopic harvesting device of FIG. 1 in which a knife is extended from the plunger. FIG. 7 illustrates an enlarged view of a plunger with the knife retracted. FIG. 8 illustrates an enlarged view of a plunger with the knife extended. FIG. 9 illustrates a cross sectional view of the actuator and handle of the device of FIG. 1 . FIG. 10 illustrates an enlarged front view of an alternative headpiece having a movable hook. FIG. 11 illustrates an enlarged sectional side view of the headpiece of FIG. 10 having the movable hook extended. FIG. 12 illustrates an enlarged bottom view of FIG. 11 . FIG. 13 illustrates an enlarged side view of the headpiece of FIG. 11 having the movable hook retracted. FIG. 14 illustrates an enlarged side view of the actuator of FIG. 1, showing the position of the components of the actuator when the plunger is retracted. FIG. 15 illustrates an enlarged side view of the actuator of FIG. 1, showing the position of the components of the actuator when the plunger is extended. FIG. 16 illustrates an enlarged side view of the actuator of FIG. 1, showing the position of the components of the actuator when the knife is extended. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a preferred implementation of an endoscopic vessel harvesting device (EVH) for the removal of vessels from a body is illustrated therein, generally referred to by reference number 100 . Specifically, the EVH 100 is often used for the removal of the saphenous vein from the leg of a patient undergoing a CABG operation. The embodiments discussed herein are directed to the removal of such saphenous veins, however, it should be noted that they are not limited to the removal of saphenous veins and could be utilized for the removal of any vessel from a patient. As described above, traditional procedures for removing the saphenous vein required the exchange of various tools multiple times for each side branch ligation and transection. Accordingly, the EVH 100 is provided to overcome the disadvantages of the prior art. The vessel harvesting device (EVH) 100 is comprised of a shaft 110 , the shaft is used to house an endoscope 116 inserted therein. The shaft 110 is preferably formed of a medical grade material, such as stainless steel. On the distal end 161 of the shaft 110 there is disposed a headpiece 112 . The headpiece 112 is preferably formed of a medical grade transparent material such as, polycarbonate. The headpiece 112 is used for dissection of a vessel from the surrounding tissue. The headpiece 112 defines a workspace 127 , which can be viewed through an endoscope 116 inserted into the shaft 110 to which the headpiece 112 is attached. Referring now to FIGS. 2-4, on a distal end 161 of the headpiece 112 there is preferably located a hook 126 . The hook 126 is angled toward the proximate end 151 of the EVH 100 . As will be discussed below, the hook 126 assists in the dissection of vessels and is used in the compression, ligation and transection of the dissected vessel. On the sides of the headpiece 112 there are extensions 130 which extend downward and towards the center of the device, as can be seen in FIG. 4 . As will be discussed below, these extensions 130 assist in the dissection of vessels. Referring back to FIG. 1, on a proximal end 151 of the EVH 100 there is disposed a handle 114 . The handle 114 is preferably formed of a thermoplastic. The handle is used to manipulate the EVH 100 . The handle 114 also preferably provides an insertion point for.the endoscope and may house various controls. Referring to FIG. 4 a plunger 118 is disposed on the distal end 161 of shaft 110 and is movable from a retracted position to an extended position within the workspace 127 . The plunger 118 interacts with a portion of the headpiece 112 . In a first variation the portion is an integrally formed hook 126 . The plunger 118 is extendable in the direction of hook 126 , and this movement facilitates the capture of vessels between the plunger 118 and the hook 126 . The EVH 100 preferably comprises a ligation means. The ligation means is preferably located on the plunger 118 as shown in FIG. 7 . The ligation means is preferably a pair of electrodes 144 which can be energized with RF energy to cauterize a vessel captured between the plunger 118 and the hook 126 . Additionally, the EVH 100 preferably comprises a transection means. The transection means is preferably housed in the plunger 118 as shown in FIG. 8 . The preferred transection means is a knife 140 housed between the electrodes 144 . The knife 140 is used to cut a vessel captured between the plunger 118 and the hook 126 and cauterized by the electrodes 144 . The plunger 118 is preferably formed of two electrodes 144 of opposite polarities, separated from one another by at least one insulator 142 , as shown in FIG. 7 . The electrodes are preferably formed of a medical grade stainless steel and are electrically connected to an RF generator as is known in the art. The electrodes are energized by either controls (not shown) located in the handle 114 , or by a foot pedal (also not shown) as is commonly used in the art, and shown in FIG. 1 . As shown in FIG. 7 it is preferable that a knife 140 is disposed between the two insulators 142 , and the electrodes 144 are separated from the.insulators 142 to isolate them from each other electrically and/or the knife 140 . The knife 140 is formed of a medical grade material, such as a stainless steel hardened to maintain a sharp edge for the life of the device. The insulators 142 are preferable formed of a medical grade insulating material such as, but not limited to polycarbonate and polyethylene, in of a thickness in the range of about 1-2 mm. The electrodes are preferably offset from one another by the insulators 142 and the knife 140 a distance 2.5 mm. This minimizes the collateral damage done to the vessel and the surrounding tissue. In an alternative implementation of the invention the knife 140 can serve as an electrode of one polarity and the two electrodes 144 can serve as a single electrode of a second polarity. Referring now to FIG. 9, the EVH 100 also includes an actuator 120 for the actuation of the plunger 118 . The actuator 120 is preferably disposed on the proximal end 151 of the shaft 110 . The actuator 120 is comprised of a control knob 122 , a biasing means 124 , a carriage 125 (shown in FIGS. 14 - 16 ), and a stop 132 . The control knob 122 is connected to the plunger 118 . The biasing means 124 may be a spring 124 , as shown in FIG. 9, and acts upon the stop 132 to return the control knob 122 to a certain position. As shown in FIG. 1, extending from the headpiece 112 to the actuator 120 and covering the shaft 110 is a plastic sheath 111 formed preferably of a polycarbonate. Referring now to FIG. 4 the sheath 111 , as shown in FIG. 1, provides a housing for a slot 146 in which the plunger 118 is slidably housed, and may also provide a second slot (not shown) for a control rod 244 , when used with a slidable hook 226 configuration, as shown in FIG. 14, and discussed below. The plunger 118 extends from the actuator 120 to the headpiece 112 , and is housed in a slot 146 . The control knob 122 , in connection with a carriage 125 , is used to move the plunger 118 from a retracted to an extended position. FIG. 3 shows the plunger 118 in a retracted position. Referring now to FIGS. 14-16, the control knob 122 is independently connected to the plunger 118 and a knife 140 housed therein. In the preferred implementation, the control knob 122 slides along a portion of the shaft 110 in a carriage 125 , as shown in FIG. 14 . The control knob 122 is prevented from moving in the carriage 125 by the biasing means 124 . The carriage 125 is connected to the plunger 118 . Therefore a movement of the carriage 125 results in a corresponding movement of the plunger 118 . When the carriage 125 has met the stop 132 , any force applied by the user on the control knob 122 causes the biasing means 124 to compress, as shown in FIG. 15 . This compression of the biasing means 124 allows the control knob 122 to move independently of the carriage 125 . The knife 140 is connected to the control knob 122 and any further movement of the control knob 122 results in movement of the knife 140 , as shown in FIG. 16 . Since the knife 140 is slidable between the two insulators 142 , additional movement of the control knob 122 after the carriage 125 has meet the stop 132 allows the knife 140 to extend beyond the end of the plunger 118 , as shown in FIG. 9, because the knife 140 is slidable between the two insulators 142 . When in the retracted position, the biasing means maintains the knife 140 in a position between the two insulators. This insures that the knife 140 will not inadvertently cut tissue which comes in contact with the headpiece. Upon subsequent release of the control knob 122 , the knife 140 is retracted into the plunger 118 by the force of the biasing means as shown in FIG. 10 . However, the biasing means 124 preferably does not move the plunger 118 in relation to the hook 126 , as can be seen in a comparison of FIGS. 15 and 16. Movement of the plunger 118 is performed by movement of the control knob 122 in the proximal direction 150 by the user which acts on the carriage 125 to move the plunger 118 , as shown in FIG. 14 . The capture, ligation and transection of a side branch vessel is as performed as follows. The operator of EVH 100 hooks a side branch vessel with the hook 126 , as shown in FIG. 5 . Upon hooking the vessel, the plunger 118 is extended compressing the vessel between the plunger 118 and the hook 126 , as shown in FIG. 6 . The electrodes 144 are then energized with RF energy, cauterizing the vessel. Then the knife 140 is extended, cutting the cauterized vessel. Referring now to FIGS. 10-13, in an alternative configuration, the portion of the headpiece which interacts with the plunger comprises a hook 226 which is slidably engaged with the headpiece 212 . In this configuration the hook 226 is connected to a control rod 244 . The hook 226 is formed preferably of a medical grade thermoplastic or elastomer. The control rod 244 is actuated by an actuation means (not shown). Since it is preferable that the control rod is flexible to conform to the shape of the head piece 212 , the control rod is preferably formed of a medical grade material, such as high density polyethylene. As shown in FIGS. 11 and 12, the control rod 244 has a stop 242 which prevents the hook 226 from extending beyond the end of the headpiece 212 . The stop 242 stops the movement of the control rod 244 upon coming in contact with capturing means 240 . The capturing means 240 limits the travel of the control rod 244 , and thereby limit the travel of the hook 226 . Referring to FIG. 13, the capturing means 240 also prevents the control rod 244 and hook 226 assembly from entering the workspace. The capturing means 240 insures that the control rod 244 and the hook 226 follow the contours of the headpiece 212 and do not block the field of view (F.O.V.) for the endoscope 216 , as shown in FIG. 16 . As shown in FIG. 11, the slidable hook 226 is also used for the ligation and transection of side branch vessels. Upon discovery of a side branch vessel, the hook 226 is slid towards the distal end 161 of the headpiece 212 using the control rod 244 . Upon reaching the stop 242 the hook 226 is properly positioned, as shown in FIG. 11 . The hook 226 is used to capture the side branch vessel and a plunger 218 is extended. The device preferably comprises similar ligation and transection means as that described above, and their descriptions are therefore not reiterated here. After transection, the hook 226 can then be retracted as shown in FIG. 13, to insure that it is not impeding the F.O.V. of the endoscope. The traditional method for the removal of the saphenous vein is well known in the art. Initially, an incision is made in the patients leg. The incision is typically three or four cm in length and provides access to the vessel. The vessel is surrounded by tissue from which it must be dissected. This is accomplished using the edge of the headpiece of the harvesting device. This allows the vessel to be accessed by the harvesting device and through the dissection the head provides a workspace to continue the dissection and proceed with removal of the vessel. During the dissection process, the surgeon will uncover numerous side branch vessels which are attached to the saphenous vein. Each of these side branch vessels must be individually dissected, ligated and transected so that the saphenous vein may be removed. A method of removing the saphenous vein using the EVH 100 as described above will now be discussed with reference to the Figures. Those skilled in the art will appreciate that the methods of the present invention limit the number of extraneous tools which must be inserted into the same incision. The method includes the steps of locating the vessel to be removed, making an incision, and inserting the EVH 100 into the incision. The blunt dissection of the vessel is performed by moving the headpiece 112 of the EVH 100 along the vessel. This separates the vessel from tissue above the vessel and exposes the vessel to the EVH 100 . Once the vessel is exposed, and separated from the surrounding tissue, a workspace 127 is defined by the headpiece 112 . The workspace provides a location for the plunger 118 to be operated, shown in FIGS. 5, 6 , and 11 . The vessel will undoubtedly have a number of side branch vessels connected to it. Each of these will have to be individually ligated and transected before removal of the vessel. Upon the exposing of a side branch vessel the headpiece 112 can be placed over the side branch as shown in FIG. 5 . With the headpiece 112 over the side branch the EVH 100 can be drawn back towards the operator so that the vessel can be captured by the hook 126 , as shown if FIG. 5 . The plunger 118 is moved in the distal direction 160 by moving control knob 122 towards the distal end 161 of the EVH 100 . Upon the plunger 118 meeting the hook 126 the vessel is captured, as shown in FIG. 6 . In the alternate configuration discussed above, the hook 226 is first extended before the vessel is captured. The captured vessel is then compressed by the pressure applied by the plunger in the distal 160 direction. The side branch vessel is sandwiched between the hook and the plunger 118 . The plunger vessel 118 may also be fitted with transection and ligation means, as show in FIGS. 7 and 8. These means are actuated by the operator using their respective controls. The surgeon can actuate the ligation means, which are preferably a pair of electrodes, by energizing the electrodes 144 with RF energy via a switch (not shown) located in the handle 114 of the EVH 100 or by using a foot pedal (not shown) as is common in the art. With the plunger 118 extended and the side branch vessel captured between the hook 126 and the plunger 118 , as shown in FIG. 6, RF energy can be supplied to the electrodes 144 . This effectively ligates the side branch vessel by cauterization. After the side branch vessel is ligated it can be transected. The side branch vessel can be transected using a knife edge 140 located in the plunger 118 between the insulators 142 , as shown in FIG. 8 . This knife 140 is actuated by moving control knob 122 in the carriage 125 in the distal 160 direction to overcome the force of the biasing means 124 , as shown in FIGS. 14-16. This movement exposes the knife 140 and transects the compressed and cauterized side branch captured between the plunger 118 and the hook 126 . Upon transection of the side branch vessel the surgeon can proceed with the dissection of the vessel and move to the next side branch vessel requiring ligation and transection. Those skilled in the art will appreciate that the methods of the present invention do not require the insertion of any extraneous tools to perform the transection and ligation procedure. Nor do they require multiple tool exchanges. Accordingly, the procedure as a whole is far easier, and efficient that those previously known. As a result the stress on the patient is reduced. Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modification are intended to be included within the scope of this invention as defined in the following claims. EXAMPLE As discussed above, the present invention has particular utility in a coronary artery bypass graft procedure (CABG), however, the use of the instruments of the present invention is now described with regard to the CABG procedure by way of example only and not to limit the scope or spirit of the present invention. A patient is prepared for cardiac surgery in a conventional manner using conventional techniques and procedures. The patient is then anesthetized and ventilated using conventional techniques. A conventional CABG procedure is performed by harvesting the greater saphenous vein from one or both of the patient's legs. The surgeon prepares an opening to the heart by dividing the patient's sternum (conventional median sternotomy) and spreading the rib cage apart using a surgical retractor. The surgeon next begins dissecting the internal mammary artery (IMA) from the chest wall of the patient, so that the distal end of the vessel may be anastomosed to the diseased lower anterior descending (LAD) coronary artery on the distal side of a lesion on the septum near the left ventricle of the heart as a source of oxygenated blood. During the surgical procedure, the surgeon optionally elects to have the patient's heart beating to perform a conventional beating heart CABG, although the surgeon has a cardiopulmonary bypass machine (CPB) primed with the patient's blood and available if it is necessary to convert the beating heart procedure into a conventional stopped heart procedure. The surgeon prepares the heart for attaching the graft vessels by cutting and pulling away the pericardium. After checking the graft vessels for patency, collateral damage and viability, the surgeon prepares to do the anastomoses necessary to bypass the lesions in the coronary arteries. The surgeon sutures the proximal end of each graft vessel to the patient's aorta and the distal end to the diseased coronary artery, distal to the blockage or lesion. The distal end of the LAD is similarly anatomosed to a coronary artery distal to a lesion in a conventional manner. The surgeon checks the bypass grafts for adequate blood flow in a conventional manner, and then completes the remainder of the operation in a conventional manner. The veins used in the CABG procedure are harvested endoscopically using the vein harvesting instruments of the present invention. Using these instruments, initially the patient's leg is positioned to be slightly bent and is turned to expose the inner leg. A marker is used to show on the skin the location of the vein to be harvested. Then an incision is created on the inner leg near the knee, through the skin and subcutaneous layers. The vein typically lies directly beneath the subcutaneous layers and so a middle portion of the vein is accessed through the incision. After some initial dissection with conventional blunt dissectors around this portion of the vein, a surgical instrument is introduced into the incision. An endoscope provides visualization of the vein and surrounding tissue within the working space inside the head. The instrument is advanced along the vein. Side branches off of the vein are ligated and divided a few millimeters away from the vein, taking great care not to injure the vein in any way. The harvesting procedure continues in this manner until the vein is hemostatically isolated from surrounding tissues and blood supply along the portion to be harvested. Then stab incisions are created through the skin and subcutaneous layers at the distal and proximal ends of the vein, ligation clips are applied, and the vessel is transected in order to remove the vein from the knee incision. The harvested vein is prepared for use as grafts in a conventional manner.
An endoscopic device including a shaft having a lumen for insertion of an endoscope therethrough, a transparent headpiece defining a workspace and disposed at a distal end of the shaft, a handle disposed at a proximal end of the shaft, a plunger disposed at the distal end of the shaft and movable between a retracted and extended position, wherein in the extended position the plunger interacts with at least a portion of the headpiece to capture a vessel therebetweeen, an actuator for moving the plunger between the retracted and extended positions, and a ligator for cauterizing the vessel captured between the plunger and the portion of the headpiece.
0
TECHNICAL FIELD [0001] The disclosure generally relates to the field of pistons for internal combustion engines. BACKGROUND [0002] Cooling channel pistons, in which a cooling channel (also known as cooling space) is arranged in the piston upper part (also known as piston crown), are known. The cooling channel generally has at least one opening into which a coolant is introduced. Once the latter has passed through the cooling channel, it leaves the cooling channel at a further opening or at the same opening. [0003] DE 10 2011 007 285 A1 relates to a piston for an internal combustion engine, having a piston upper part and a piston lower part, an internal, preferably annular cooling channel for cooling the piston during operation of the internal combustion engine, and at least one inlet opening arranged on the piston lower part and at least one outlet opening arranged on the piston lower part, an inflow of coolant into the cooling channel and an outflow of coolant out of the latter taking place via said at least one inlet opening and at least one outlet opening, respectively, wherein the at least one inlet opening and/or the at least one outlet opening is/are surrounded by an annular bead or a ramp-like elevation which prevents a coolant level from dropping below predefined level, and which is formed integrally with the piston lower part. However, the annular bead can be created only at the level of the displaced material. Therefore, the possibility of influencing the level of the coolant in the cooling channel is also limited. SUMMARY [0004] The invention relates to a cooling channel piston for internal combustion engines and to a method for regulating the cooling level in the cooling channel. [0005] Therefore, it is the object of the invention to be able to set the coolant level in a greater range and also to provide a method for setting the coolant level in the cooling channel. [0006] This object is achieved by a piston and a method having the features in the independent claims. [0007] The invention provides a piston, in particular for an internal combustion engine, having a piston lower part and a piston upper part, an internal, preferably annular cooling channel and at least one inlet opening arranged on the piston lower part and at least one outlet opening arranged on the piston lower part, an inflow of coolant into the cooling channel and an outflow of coolant out of the latter taking place via said at least one inlet opening and at least one outlet opening, respectively, wherein the at least one inlet opening and/or the at least one outlet opening is/are formed by a rim hole and the latter is formed integrally with the piston lower part, wherein the at least one rim hole has a thread into which at least one tubular element is inserted. As a result of the provision of a thread in at least one inlet opening and/or outlet opening, any desired elements through which coolant can flow can be screwed into the piston. As a result of the piston being manufactured with at least one thread, subsequent manufacture with regard to the coolant level in the cooling channel of the piston can take place. The pistons in question can be manufactured identically up to this step. [0008] Furthermore, provision is made according to the invention for the at least one rim hole to terminate level with the surface of a cooling channel wall. As a result, the coolant level can be set freely via the length of engagement of a tubular element. Thus, there is no minimum filling level. [0009] Alternatively, provision is made according to the invention for at least one rim hole to have at least one collar. As a result, the thread to be introduced there is reinforced. The connection between the piston and screwed-in component, for example a tubular element, becomes firmer. [0010] Furthermore, provision is made according to the invention for the at least one collar to be formed on that side of the cooling channel wall that faces the pin bores. As a result, the at least one rim hole can be created in the piston assembled from the piston lower part and piston upper part. [0011] Alternatively, provision is made according to the invention for the at least one collar to be formed on that side of the cooling channel wall that faces away from the pin bores and thus to project into the cooling channel. As a result, a minimum coolant filling level is achieved in the cooling channel. [0012] Furthermore, provision is made according to the invention for the at least one tubular element to terminate flush with the at least one rim hole or with the collar of the at least one rim hole. In this case, the tubular element serves to supply coolant to the cooling channel better, but not to influence the coolant level in the cooling channel. [0013] In a further configuration, provision is made according to the invention for the at least one tubular element to project into the cooling channel from the at least one rim hole and/or the collar of the at least one rim hole. As a result of the depth of penetration of the tubular element into the cooling channel, the level of the coolant in the cooling channel is influenced. [0014] Furthermore, provision is made according to the invention for the at least one tubular element to project from the thread in the direction away from the cooling channel. In this case, the tubular element serves to supply coolant to the cooling channel better; for example, the coolant can be delivered directly into the tubular element with the aid of a nozzle. [0015] Furthermore, provision is made according to the invention for that end of the at least one tubular element that is directed away from the cooling channel to be funnel-shaped. A funnel-shaped structure of the tubular element increases the collection of sprayed-in coolant from the nozzle. As a result of the funnel-shaped configuration of the tubular element, tolerances of the oil jet can be compensated. If the oil jet is fanned out, virtually the entire or preferably the entire volume flow can nevertheless be passed into the cooling channel between top and bottom dead center during the up and down movement of the piston. [0016] According to the invention, a method is provided for regulating the coolant level in a cooling channel of a piston, in particular for internal combustion engines, which has at least one inlet opening and/or outlet opening in the cooling channel, formed by at least one rim hole, wherein the coolant level in the cooling channel is set via an adjustable tubular element. [0017] Furthermore, provision is made according to the invention for the rim hole for forming the at least one inlet opening and/or outlet opening to have been created by friction drilling. Friction drilling does not produce any chips and is thus ideal for use in the production of pistons, since when the piston is used in an internal combustion engine, any chips would jeopardize operation of the internal combustion engine. [0018] Furthermore, provision is made according to the invention for the thread in the rim hole, which forms the at least one inlet opening and/or outlet opening, to have been created by thread cutting. Thread cutting is a known and proven method in manufacturing. Therefore, thread cutting represents an alternative to thread forming. [0019] Alternatively, provision is made according to the invention for the thread in the rim hole to have been created by thread forming. Thread forming is the ideal follow-on step to friction drilling, since, just like in friction drilling, no chips are produced in thread forming, either. [0020] Furthermore, provision is made according to the invention for the cooling level to be regulated via the length of engagement of the tubular element in a thread located in the cooling channel. The length of engagement in this case denotes that length of the tubular element that projects into the cooling channel from the rim hole or the collar of the rim hole. By way of a thread, particularly precise regulation of the coolant level is possible. After the coolant level has been set, the tubular element can be secured in a force-fitting, form-fitting and/or material integral manner, in order that the setting of the coolant level is fixed during operation of the internal combustion engine. [0021] The coolant level is regulated by the variation in the depth of engagement of the tubular element in the cooling channel. [0022] Furthermore, provision is made for the tubular element to serve to transport coolant. Thus, coolant can be supplied to and/or drained from the cooling channel. Its design can be matched to the particular application. [0023] A method is provided for regulating the coolant level in a cooling channel of a piston, in particular for internal combustion engines, wherein the coolant level in the cooling channel is set via an adjustable tubular element. By way of this method, a precisely defined quantity of coolant can be kept in the cooling channel of the piston during operation of the internal combustion engine. [0024] The piston in question is also referred to as a cooling channel piston and can consist of at least two piston parts, for example a piston lower part and a piston upper part, which are assembled to form a piston by a force-fitting and/or form-fitting and/or materially integral joining method. Alternatively, the piston comprising the piston lower part and piston upper part can also be produced integrally in a production process, for example a casting method; in this case, the working step for joining the piston lower part and piston upper part is dispensed with. In order to create the cavities, grains of sand for example are used in a casting method, and after the casting process, these can be flushed out through openings provided separately for this purpose. These openings are closed after the flushing-out operation. [0025] At the start of the friction drilling process, a relatively high axial force and rotational speed are required in order to create the necessary frictional heat between the friction drill and the cooling channel wall. In this case, the temperature of the friction drill rises very quickly to for example about 650° to 800° C., and that of the cooling channel wall rises for example locally to about 600° C. [0026] The material that is displaced first out of the cooling channel wall initially flows upward counter to the feed direction, and with increasing depth of penetration, the actual rim hole is created in the feed direction. The ratio between material flowing upward and downward is for example about ⅓ to ⅔. This varies depending on the drilling diameter and the material thickness and can also be less (for example ¼ to ¾). [0027] Once the friction drill has penetrated through the cooling channel wall, it then either forms the material that has flowed upward into a homogeneous collar or bead or directly removes this material again, depending on the type of friction drill. In this case, the geometric shape of the tool is reproduced in the material. [0028] It has surprisingly been found that friction drilling (also known as flow drilling or form drilling) is an advantageous chipless method for producing rim holes in pistons, in particular in pistons for internal combustion engines. In this case, the material is not removed but displaced with the aid of force and frictional heat, thrown up in the form of a bead and formed into a type of bushing or rim hole in the piston, thereby avoiding the production of chips. The displaced piston material that has been thrown up in the form of a bead can be formed into a collar or removed. The stable bushings or rim holes that are produced are created by material displacement and not by removal of material. This homogeneous deformation not only effects additional material consolidation but also has a considerable time- and material-saving effect. The shape and diameter of the rim hole created in the piston are determined by the dimensions of the cylindrical part of the friction drill. On account of material displacement, no chips arise during the production of an opening in a piston. The displaced material is advantageously used to shape the region around the passage opening of the friction drill. As a result of the formation of a collar by the material thrown up in the form of the bead, the thread flight that is subsequently to be created can be extended. The stability with regard to the component, for example tubular element, accommodated in the thread is increased. In a screw-in connection, the screw-in depth has an influence on the stability of the connection between the accommodated piston and the screwed-in element, for example a tubular element. The risks of damage, cratering, thread deformation and/or thread shear are reduced by a screw-in depth increased by a collar on the rim hole in a piston. The screw-in depth is that length along which the component, for example a tubular element, that is received by the thread in the piston and the internal thread are actually in load-bearing engagement. A thread is provided to be fully load-bearing only in the range of the ideal screw-in depth. The terminal thread turns are not considered to be equivalent in terms of load-bearing capacity to the fully load-bearing thread turns located in between. Therefore, length deductions from the physically load-bearing screw-in depth are carried out, resulting in the ideal screw-in depth. In this way, a collar formed on the piston by friction drilling advantageously increases the number of the thread turns at the connection in the piston, for example the connection between the piston and a tubular element. The weakening of the load-bearing capacity at the thread runouts of internally threaded component and component received in the thread is referred to as end influences. As a result of the formation of the collar and the thread introduced into the latter, the end influences on the screw-in connection on the piston are at least compensated. Advantageously, the load-bearing capacity of the thread is increased by the formation of a collar at the rim hole in the piston, produced by friction drilling, compared with a conventional opening, produced for example by drilling or casting, in the piston. [0029] The application of the friction drilling method to pistons results, in addition to the abovementioned advantages, in the following advantages, inter alia. As a result of the application of the friction drilling method in pistons, stable rim holes or bushings for receiving screw connections, such as tubular element through which coolant can flow, are produced. Furthermore, diagonal friction drilling is possible, in which case the central axis of the friction drilled hole or of the resulting rim hole deviates by an acute or obtuse angle from the vertical line formed by the piston stroke axis. Friction drilling is a chipless production method and connecting elements are not necessary. Friction drilling entails a large saving of time, work and material, since no additional components are necessary. The production of rim holes in pistons takes place in only one work operation. Friction drilling is a fully automatable method with minimal setup times. No rivet nuts or weld nuts are required for joining components, for example tubular elements. The friction drilling method affords greater reliability by homogeneous deformation and the service life of the piston is thus increased. Friction drills have long service lives and produced excellent surface qualities. No waste costs and disposal costs are incurred since the method is chipless. Furthermore, it is particularly advantageous that no chips jeopardize the operational reliability of the piston in the internal combustion engine. Thus, less failure of products can be noted. Friction drilling therefore affords high process reliability through durable carbide tools. [0030] Friction drills are solid carbide tools having a polygonal contour. When pressed at a high rotational speed and axial force against thin-walled metal materials, they produce extreme frictional heat. As a result, the material of the cooling channel wall can be plasticized locally at the friction drilling position. The friction drill is guided through the cooling channel wall within a few seconds. As a result, without any loss of material whatsoever, a rim hole or a bushing is produced from the starting material. The length of this bushing can be for instance three to five times the original material thickness. The maximum material thickness to be machined is proportional to the core hole diameter of the friction drill. Depending on the core hole diameter, material with a thickness of between 0.5 mm (with optimum lining) and 12 mm (requires very high spindle power) is able to be machined. Depending on the material thickness and quality, it thus possible for 5000 to 10000 bores to be produced with a friction drill. [0031] During thread forming, the advantages of friction drilling are pursued. Chipless bushing or rim-hole production effects strain hardening of the material to be machined and the cold rolled-in thread additionally reinforces the thread turns. For thread forming, any conventional thread cutting device can be used. However, care should be taken to carry out machining with a higher rotational speed (3 to 10 times the process speed). During thread forming, it is also possible to machine using a hand drill. The latter should in this case exhibit right-hand and left-hand rotation and sufficient power. Hand drill is the name given to handheld drilling machines. Depending on the construction type, they are suitable for friction drilling and/or thread forming in different materials such as metal or metal alloys of a piston. A common feature of all hand drills is the possibility of introducing friction drills and other rotating tools, for example thread formers, into a chuck fitted to the end side. The most important distinguishing feature of hand drills is the type of energy supply, which can occur manually by hand with the aid of muscular force, electrically, hydraulically or pneumatically. Such hand drills can preferably be used to produce small batches of pistons. Thus, any number of pistons that is desired by the customer can be produced with rim holes produced by friction drilling and threads produced by thread forming. [0032] In what is known as threading, the thread former pushes the material of the rim hole or of the bushing into the thread flanks and, by chipless cold forming, effects compaction of the microstructure of the piston material. As a result, very high strength of the thread in the piston and exact thread guidance is achieved. As a result of the uninterrupted course of the piston material in the thread turns and the cold rolling of the thread forming process, a highly loadable connection has been created. On account of the exact thread guidance, there is no risk of miscutting. [0033] The production of threads on pistons with the aid of the thread forming method has, inter alia, the following advantages. Thread forming is a chipless method and thus advantageously supplements the friction drilling method. Since no chips are produced in this production step, they cannot subsequently jeopardize the operation of the piston in an internal combustion engine. In thread forming, an increase in productivity is achieved by a higher process speed. The connection produced in the piston by thread forming is highly loadable and has exact thread guidance. As a result for example of a special TiN coating, an increase in service life can be achieved. Furthermore, the length and wall thickness of the rim hole produced in the friction drilling method are fully retained. The thread forming method, too, is a fully automatable method. Existing production facilities can be used, since the thread forming method is employable on all conventional thread cutting devices. [0034] In contrast to conventional thread cutting, thread forming in conjunction with friction drilling has enormous advantages. The previous warm displacement of the material during friction drilling and the subsequent cold rolling during thread forming effect strong consolidation of the material of the cooling channel wall. This ensures highly pull-out resistant threaded connections. The chiplessly operating thread former brings about a considerable increase in productivity on account of the very high cutting rate and extremely long service life. [0035] The opening to which the coolant is fed is oriented in the direction of a cooling oil nozzle, wherein the coolant is sprayed out of the cooling oil nozzle in the direction of the opening. In this case, care should be taken during the fitting of the cooling channel piston in the cylinder of the internal combustion engine and also during operation to ensure that the cooling oil jet leaving the cooling oil nozzle during the oscillating up and down movement of the piston in the cylinder chamber strikes precisely the opening on the underside of the piston inner region in order that the cooling oil can pass into the cooling channel. [0036] The cooling channel is realized for example in a manner known per se with the aid of a lost core during the casting of the cooling channel piston, wherein at least one opening, for example a bore, is introduced from the piston inner region after the casting process, in order to reach the lost core and flush it out. [0037] In addition to this embodiment, it is known that an extended inflow is realized as an additional bore in the actual piston. In this case, a thickening is generally cast or formed in the piston main body in the region of the piston hub, wherein this thickening is subsequently drilled out. [0038] This extended inflow opening from the piston inner side in the direction of the cooling channel has the advantage that the coolant sprayed or introduced into this inflow can be guided better and deflected in a more targeted manner into the cooling channel and circulate therein. [0039] The invention is based on a cooling channel piston in which, following the production of the cooling channel piston in any desired manner, a cooling channel (or a plurality of cooling channels all portions of the like) is provided in the piston crown, wherein the at least one opening for the inflow of the coolant is located approximately beneath the plane in which the piston crown ends as viewed toward the bottom (that is to say above the pin bore or the crown of the pin). Such a piston, which forms the basis of the invention, thus does not have a thickening at the piston hub, which is cast and formed and subsequently drilled out. [0040] Proceeding from the at least one opening for the inflow (or outflow) of the coolant approximately beneath the plane of the axial end of the piston crown, a component is arranged at the inflow opening, said component forming an extended cooling channel inflow (or an extended cooling channel outflow). This component is in one piece or can also be produced from several components. The at least one component consists for example of a steel material (e.g. sheet metal), plastics material, a composite material or a light metal material and can be produced cost-effectively for example in the form of a widening or narrowing tubular component or tubular element. The attachment can take place by a simple attachment method such as screwing, adhesive bonding, stitching, form-fitting, clip-fastening, soldering, welding, shrink-fitting or pressing or the like. [0041] The component can be embodied such that it projects into the interior of the cooling channel inflow, in other words beyond the plane in which the inflow or outflow opening is located. The resulting shoulder that projects into the cooling channel advantageously prevents a backflow of coolant in the direction of the component. This ensures that, during the oscillating up and down movement of the piston in the cylinder of the internal combustion engine, a certain quantity of coolant always remains in the cooling channel. This can absorb heat from the surrounding regions of the piston crown and is mixed with inflowing fresh coolant by the shaker action and as a result can dissipate heat in an improved manner. [0042] As a result of the extended cooling channel inflow by the supplementation of the cooling channel with the at least one component according to the invention, the filling of the cooling channel piston with coolant can be considerably improved especially at bottom dead center. Measurements have in this case revealed an improvement of 60% not only for filling but also for heat dissipation. [0043] Furthermore, there is a reduction in weight when thickened regions, into which a bore would need to be introduced for the purpose of an extended cooling channel inflow, do not have to be provided next to the piston hub. As a result, the attachment of the piston skirt of the cooling channel piston to its hub is more convenient. [0044] Furthermore, it is conceivable to equip any desired pistons which have a cooling channel, wherein the cooling channel itself has at least one outflow and/or inflow opening, with an extended cooling channel inflow or outflow according to the invention. [0045] This invention is intended to realize an extended cooling channel inflow by way of one or more additional components on the piston. The extended cooling channel inflow is intended to be provided as (an) additional component(s) for pistons for an internal combustion engine, for example as a tubular element. [0046] The invention makes it possible to considerably improve the filling of the cooling channel. More cost-effective production is possible. [0047] An extended inflow has hitherto been realized as an additional bore in the actual piston. A thickening is cast or formed in the piston material at the piston hub and is subsequently drilled out. This has been state of the art for many years in the case of aluminum pistons; in this case the bore can be cast. [0048] As a result of the extended cooling channel inflow, the filling of the cooling channel in the piston with cooling oil can be considerably improved especially at bottom dead center. Measurements show an improvement of up to 60%. [0049] The invention achieves more cost-effective production of the extended cooling channel inflow, especially in pistons which are not cast. With such a solution, the attachment of the piston skirt to the hub is more cost-effective, since no material has to be provided to be subsequently drilled out. A reduction in the piston weight or the mass of the piston is possible. However, in the prior art, the piston is embodied with the conventional design, that is to say the thickening is forged on and subsequently the extended inflow is drilled out. [0050] It is also possible to produce a relatively short collar, with regard to the passage length of the inlet opening and/or outlet opening, by friction drilling. In this case, the cooling action is primarily improved in that a collar is produced in the cooling channel, said cooling channel preventing backflow of the cooling oil. For extension, a small tube, for example a tubular element, can be screwed in. [0051] This method also has the advantage that a bore is created without chips being produced. Friction drilling can therefore replace the currently very complicated opening using an ECM method. Electrochemical machining (ECM) is a material-removing manufacturing method in particular for very hard materials, belonging to the cutting group of methods. ECM is suitable for simple deburring work all the way through to the production of openings in pistons. [0052] In the case of a rim hole having a collar or surrounded by an annular bead or a ramp-like elevation, the coolant level can be prevented from dropping below a predefined level. This at least one rim hole is implemented in the cooling channel wall facing the pin bores. BRIEF DESCRIPTION OF THE DRAWINGS [0053] Further configurations of the invention are specified herein which further advantages can be gathered. Exemplary embodiments of the invention are described in the following text and shown in the figures, in which: [0054] FIGS. 1A and 1B each show a sectional view of a piston according to the invention transversely to the pin axi;, [0055] FIGS. 2 shows sectional views of the piston upper part and piston lower part before they are joined to form a piston; [0056] FIGS. 3A and 3B each show a sectional view of the piston lower part from FIG. 2B during machining; [0057] FIG. 4 shows a sectional view of a piston assembled from the piston upper part and piston lower part according to FIGS. 2 ; [0058] FIG. 5 shows a sectional view of a piston according to FIG. 4 during machining; [0059] FIG. 6 shows a sectional view of a piston according to FIG. 5 during thread forming; [0060] FIG. 7 shows a sectional view of a piston according to FIG. 6 after the thread has been completed; [0061] FIGS. 8 schematically shows the machining steps A through G during the friction drilling of a piston; [0062] FIGS. 9 shows the configurations A through H of friction drilled holes in pistons; and [0063] FIG. 10 schematically shows the production of a thread. DETAILED DESCRIPTION [0064] In the following description of the figures, terms such as top, bottom, left, right, front, rear etc. relate exclusively to the exemplary illustration and position, selected in the respective figures, of the device and other elements. These term should not be understood as being limiting; in other words, these references can change as a result of different positions and/or a mirror-symmetrical construction. [0065] FIGS. 1A, 1B, 2, 3A, 3B, 4, 5, 6 and 7 show a piston 1 or components of the piston 1 in the form of a piston lower part 2 and/or of a piston upper part 3 . The following description of the figures deals with the common features of the piston 1 in question. [0066] The piston lower part 2 has at least one pin bore 4 . Furthermore, the piston 1 has a radially encircling cooling channel 5 behind a ring zone 7 that is not shown in more detail. This cooling channel 5 is bounded in the direction of the pin bores 4 by a cooling channel wall 6 . The piston upper part 3 has a combustion bowl 8 . The combustion bowl 8 can be present, but does not have to be. During operation of the piston 1 in an internal combustion engine, the piston 1 moves in the direction of a piston stroke axis 9 . The piston lower part 2 and the piston upper part 3 are joined to form a piston 1 by way of a materially integral connection. An appropriate method for materially integral joining is welding, in particular friction welding. During welding, an external joining seam 16 and an internal joining seam 17 are produced. FIG. 2 shows the piston lower part 2 before the piston 1 is assembled and FIG. 2 shows the piston upper part 3 before the piston 1 is assembled. [0067] The cooling channel wall 6 has at least one rim hole 12 . This rim hole 12 is provided with a collar 13 (see FIGS. 1A, 1B, 3A, 3B, 6 and 7 ). The at least one rim hole 12 serves as at least one inlet opening and/or the at least one outlet opening for coolant. The at least one rim hole 12 is provided with a thread 14 . A straight tubular element 15 (having the same diameter) or a tubular element 115 that is widened on at least one side (in a funnel-shaped manner, having a diameter that varies at least in subregions) can be introduced into this thread 14 . Coolant flows into and/or out of the cooling channel 5 via these tubular elements 15 , 115 . The level of the coolant in the cooling channel 5 can be set by the length of engagement of these tubular elements 15 , 115 . X indicates the distance between the cooling channel wall 6 and the opening located at the end of the tubular elements 15 , 115 . Y denotes the distance between the collar 13 and the opening located at the end of the tubular elements 15 , 115 . The level of the coolant in the cooling channel 5 is set using the smallest value of X. If several tubular elements 15 , 115 have been installed, the tubular element 15 , 115 that projects into the cooling channel 5 with the smallest free length thus determines the level of the coolant in the cooling channel 5 . If the inlet opening 10 is located higher up than the outlet opening 11 , a continuous coolant flow is established between the inlet opening 10 and the outlet opening 11 . The level of the coolant in the cooling channel 5 is determined by the position of the outlet opening 11 in the cooling channel 5 . The end-side opening, located in the cooling channel 5 , of the tubular elements 15 , 115 can thus act as the inlet opening 10 and/or outlet opening 11 . At the outer circumference, the tubular elements 15 , 115 have a thread at least in one subregion. This thread is executed such that it can be screwed into the thread 14 . Depending on the thread structure, very precise adjustment of the inlet opening 10 and/or outlet opening 11 in the cooling channel 5 is allowed. Thus, the coolant level in the cooling channel 5 of the piston 1 can be set precisely for subsequent use. It allows a piston 1 having different coolant levels to be marketed. Furthermore, a tubular element 15 with a straight design or alternatively a tubular element 115 that is widened on at least one side can be installed. The piston 1 is therefore variable in terms of the coolant quantity provided during operation in an internal combustion engine. Depending on the piston, it is also possible for only one tubular element 15 , 115 to be used. The tubular element 115 that is widened on at least one side is suitable in particular for collecting a coolant jet sprayed through nozzles. [0068] FIG. 1A shows the piston 1 with two tubular elements 15 . FIG. 1B shows a piston 1 having a tubular element 115 that is widened on at least one side. Following the adjustment of the tubular elements 15 , 115 , these can be fixed in a force-fitting, form-fitting or materially integral manner. Fixing can take place for example at the rim hole 12 or at the cooling channel wall 6 . [0069] FIGS. 3A and 3B show a piston lower part 2 during the production of a rim hole 12 in the region of the cooling channel wall 6 with the aid of a friction drill 18 . The rim hole 12 is virtually complete here, since the collar 13 has already been fully formed. [0070] FIG. 4 shows the piston 1 according to FIGS. 2 (piston upper part 3 ) (piston lower part 2 ) after a materially integral joining method, in particular a friction welding method, has been carried out. Weld beads have been formed at the joining seams 16 , 17 . [0071] FIG. 5 shows a piston 1 assembled from the piston lower part 2 and piston upper part 3 during the action of friction drills 18 on the cooling channel wall 6 . The friction drilling method can be applied to the piston lower part 2 before joining (see FIGS. 3A and 3B ) or after joining (see FIG. 5 ). After joining or machining of the cooling channel wall from the direction of the pin bores 4 , the collar 13 is produced on that side of the cooling channel wall 6 that faces the pin bores (see FIGS. 3A and 5 ). As a result of the subsequent forming of a thread 14 (see FIGS. 5 and 6 ) or the forming of a thread 14 from the direction of the pin bores 4 (see FIGS. 3A and 6 ) into the rim hole 12 , it is not necessary for a collar to be produced within the cooling channel 5 ; as a result of the tubular element 15 , 115 , the level of the coolant in the cooling channel 5 can be set freely. The collar 13 develops its thread-extending action and thus also its connection-reinforcing action regardless of whether it is arranged on that side of the cooling channel wall 6 that faces the pin bores 4 or is arranged on that side of the cooling channel 6 that faces away from the pin bores 4 . Thus, the machining of the cooling channel wall 6 can take place by friction drilling and subsequent thread forming can also take place on the piston lower part 10 and piston upper part 11 . Alternatively, the combination of friction drilling and thread forming can be carried out on a piston cast or forged in one piece. [0072] FIG. 6 schematically shows the production of the thread 14 in the rim hole 12 by way of a thread forming method. A thread former 19 for producing the thread 14 acts on the rim hole 12 , previously produced by friction drilling, in the cooling channel wall 6 . [0073] FIGS. 1A, 1B, 3A, 5, 6 and 7 show the parallel production of two rim holes 12 or two threads 14 ; it should be noted, however, that it is also possible for only one rim hole 12 or one thread 14 to be produced, as illustrated in FIG. 3B . It is also possible for more than two rim holes 12 with threads 14 to be formed on the piston 1 , for example on a cooling channel wall 6 of the cooling channel 5 . It is also possible for a central cooling chamber (not illustrated here) to be provided with at least one rim hole and at least one thread. [0074] FIG. 7 shows a piston 1 after the production of rim holes 12 with threads 14 . [0075] The friction drilling process illustrated schematically in FIGS. 8A to 8G comprises the following steps. [0076] The first step, illustrated in FIG. 8A , contains the placing of the top of the friction drill 18 on the cooling channel wall 6 . [0077] FIGS. 8B and 8C show preheating. To this end, the friction drill 18 is pressed with high axial force and rotational speed against the cooling channel wall 6 , with the result that the necessary frictional heat is generated and the material thereof is heated up. The friction drill 18 can then penetrate into the material and form the rim hole 12 . [0078] The third step is illustrated in FIGS. 8D to 8F and comprises the forming operation. The friction drill 18 initially displaces the material of the cooling channel wall 6 upward counter to the feed direction. With increasing depth of penetration, the rim hole 12 is then produced in the feed direction. The ratio between the material flowing upward and the material flowing downward is about ⅓ to ⅔. [0079] FIG. 8G shows the fourth step, shaping. The friction-formed rim hole 12 is finished. Depending on the friction drill 18 , the material of the cooling channel wall 6 that flowed upward is formed into a homogeneous collar 13 or bead. In the tools trade, the friction drills required for this purpose are usually designated as the “forming” or “standard” type. Alternatively, the material of the cooling channel wall 6 that flowed upward was directly removed again. In the tools trade, the friction drills required for removal are usually designated as the “cutting” or “flat” type. If the collar 13 has been removed or virtually removed, a tubular element 15 , 115 can nevertheless be advantageously provided in the thread 14 formed in the rim hole 12 . It is also possible for two tubular elements 15 , 115 to be introduced into a thread 14 , wherein they preferably butt against one another within the thread turns. [0080] The collar 13 is formed depending on the tool type, for example as a rim in the form of a sealing ring or as a planar surface. FIGS. 9A to 9H show configurations of rim holes 12 with collars 13 , produced by different tool types. [0081] FIG. 10 schematically shows the production of the thread 14 by thread forming. The process sequence during thread forming is as follows. [0082] The production of the thread 14 by thread forming is referred to as threading; in this case, the thread former 19 pushes the material of the rim hole 12 into the thread flanks and effects compaction of the microstructure by way of chipless cold forming. As a result, very high strength of the thread 14 and an exact thread guidance are achieved. As a result, on account of the uninterrupted course of the material in the thread turns and the cold rolling of the thread forming process, a highly loadable connection has been produced. On account of the exact thread guidance, there is no risk of miscutting.
The invention relates to a piston in particular for an internal combustion engine, having a piston lower part, an upper part, an internal cooling channel having at least one coolant inlet opening and at least one outlet opening defined by a rim hole. The rim hole having a screw thread into which at least one tubular element is inserted and selectively positioned relative to the cooling channel for regulating the coolant level in a cooling channel.
5
CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application claims priority from Japanese Patent Application No. JP 2010-111484 filed in the Japanese Patent Office on May 13, 2010, 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 to a battery pack, an electronic device, and an inspection method of a battery pack, and more particularly, to a battery pack used in a portable electronic device, such as a notebook computer, an electronic device including the same, and an inspection method of a battery pack. [0004] 2. Description of the Related Art [0005] Many portable electronic devices, for example, notebook computers, are driven by a battery pack. There have been proposed various techniques for such a battery pack to ensure safety by preventing serious accidents, such as emission of smoke from the battery pack and firing of the battery pack as are described, for example, in JP-A-2010-40499 and JP-A-2005-321963. [0006] According to a technique proposed in JP-A-2010-40499, a microcomputer is incorporated in a battery pack to calculate a charge current including temperature information of the battery pack using the microcomputer so that a current amount and an output stopping function on the charger side are controlled according to the calculation result. [0007] Further, according to a technique proposed in JP-A-2005-321963, information on a defect of a battery pack is detected by a power supply controller in an electronic device when the battery pack is attached to the electronic device so that charge to the battery pack is regulated in the event of a defect. SUMMARY OF THE INVENTION [0008] As has been described, various inspection techniques have been proposed to improve safety of the battery pack in the related art. However, it is quite difficult to detect all abnormal causes of the battery pack by various inspection techniques described above. For example, in order to detect an abnormal event causing a slight variance that is difficult to detect during charge and discharge cycles, special equipment or a circuit change becomes necessary separately. Further, it is well anticipated that the safety standards for the battery pack are set more strictly. [0009] Thus, it is desirable to further improve safety of a battery pack by detecting an abnormal cause that has been difficult to detect in the related art, using a simpler configuration. [0010] According to an embodiment of the present invention, there is provided a battery pack including a chargeable and dischargeable battery, and a microcomputer that acquires information on a voltage drop across the battery in a condition equivalent to no load and stores the information therein. [0011] The phrase, “condition equivalent to no load”, referred to herein includes not only a condition in which the battery pack is neither charged nor discharged, but also, for example, a condition in which power consumption of the battery pack is constant with respect to time. [0012] According to another embodiment of the present invention, there is provided an electronic device including: a chargeable and dischargeable battery, a voltage information acquisition portion, and an abnormal determination portion. Functions of the respective components are as follows. That is, the voltage information acquisition portion acquires information on a voltage drop across the battery in a condition equivalent to no load and stores the information therein. The abnormal determination portion reads out the information on the voltage drop across the battery stored in the voltage information acquisition portion and determines presence or absence of an abnormality in the battery on the basis of the read information on the voltage drop across the battery. [0013] According to still another embodiment of the present invention, there is provided an inspection method of a battery pack in an electronic device including the battery pack described above, a battery pack attachment portion to which the battery pack is attached, and an abnormal determination portion. The inspection method is carried out as follows. Herein, the abnormal determination portion determines presence or absence of an abnormality in the battery pack attached to the battery pack attachment portion. Initially, the microcomputer in the battery pack acquires information on a voltage drop across the battery in a condition equivalent to no load and stores the information therein. Subsequently, the abnormal determination portion reads out the information on the voltage drop across the battery stored in the battery pack via the battery pack attachment portion. The abnormal determination portion then determines the presence or absence of an abnormality in the battery pack on the basis of the read information on the voltage drop across the battery. [0014] As has been described, according to the embodiments of the present invention, the microcomputer (or the voltage information acquisition portion) in the battery pack acquires information on a voltage drop across the battery while the battery pack is in a condition equivalent to no load and makes an abnormal determination of the battery pack on the basis of the acquired information. It thus becomes possible to detect an abnormal event causing a slight variance that is difficult to detect while the battery pack is charged or discharged. [0015] Hence, according to the embodiments of the present invention, it is possible to detect even an abnormal event causing a slight variance that is difficult to defect during charging and discharging cycles. Also, according to the embodiments of the present invention, the microcomputer in the battery pack acquires information on a voltage drop across the battery in a condition equivalent to no load and makes an abnormal determination of the battery pack on the basis of the acquired information. Hence, in the embodiments of the present invention, for example, neither special equipment nor a circuit change is necessary in order to detect an abnormal event causing a slight variance. [0016] In other words, according to the embodiments of the present invention, it is possible to detect an abnormal cause of the battery pack that has been difficult to detect in the related using a simpler configuration, which can in turn further improve safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1A and FIG. 1B are outward perspective views of an information processing apparatus according to an embodiment of the present invention; [0018] FIG. 2 is a block diagram showing the configuration of the information processing apparatus according to the embodiment of the present invention; [0019] FIG. 3 is a view schematically showing the configuration of a battery pack according to the embodiment of the present invention; and [0020] FIG. 4 is a flowchart depicting the procedure of an inspection method of the battery pack according to the embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT [0021] Hereinafter, examples of an electronic device, a battery pack, and an inspection method of a battery pack according to an embodiment of the present invention will be described with reference to the drawings in the following order. [0022] 1. Configuration of information processing apparatus [0023] 2. Configuration of battery pack [0024] 3. Inspection method of battery pack [0025] In the following, descriptions will be given to a case where a portable information processing apparatus, such as a notebook computer, is used as an electronic device by way of example. It should be appreciated, however, that the present invention is not limited to this case. For example, the configuration of a battery pack and an inspection method thereof described below are also applicable to arbitrary electronic device and electric automobile driven by a battery pack. <1. Configuration of Information Processing Apparatus> [Outward Configuration of Information Processing Apparatus] [0026] FIG. 1A and FIG. 1B are outward perspective views of an information processing apparatus according to an embodiment of the present invention. FIG. 1A is an outward perspective view of the information processing apparatus on a display screen side described below and FIG. 1B is an outward perspective view of the information processing apparatus on the side opposite to the display screen. [0027] An information processing apparatus 100 includes a main body portion 1 , a display portion 2 , and two hinges 3 . In an example shown in FIGS. 1A and 1B , the two hinges 3 are attached to the main body portion 1 in the vicinity of the both ends of a longer end portion 1 a on the side of the display portion 2 . The display portion 2 is attached to the main body portion 1 via the two hinges 3 . Also, the display portion 2 is attached to pivot with respect to the main body portion 1 about a line linking centers of the two hinges 3 as a center axis. The display portion 2 is opened and closed with respect to the main body portion 1 by pivotal motions of the display portion 2 . [0028] The main body portion 1 includes a palm rest unit 4 (keyboard unit) forming a portion on the top side (side opposing the display portion 2 ) and a main body unit 5 forming a portion on the bottom side of the main body 1 . The main body portion 1 is formed by integrally combining the palm rest unit 4 and the main body unit 5 . Both the palm rest unit 4 and the main body unit 5 are formed of a plurality of members without noticeable screws or the like on the exterior. [0029] The palm rest unit 4 is provided with operation devices, for example, a keyboard 6 , a stick pointer 7 , and a first click button 8 . The stick pointer 7 is an operation device used, for example, for an operation to move a cursor (pointer) displayed on a display screen 10 described below and an operation to scroll the display screen 10 . [0030] Although it is not shown in FIG. 1A and FIG. 1B , the main body unit 5 incorporates, for example, a printed circuit board on which a plurality of electronic components are mounted, a radiation unit, and drives, such as a hard disc drive. On the printed circuit board are mounted a CPU (Central Processing Unit), a memory, and other electronic components. [0031] As is shown in FIG. 1B , the main body unit 5 includes a battery pack 20 re-attachable to the main body unit (main body portion 1 ) on the bottom side. The internal configuration of the battery pack 20 will be described in detail below. [0032] Further, the main body unit 5 includes a battery pack attachment portion 21 to which the battery pack 20 is attached. The battery pack attachment portion 21 has input and output terminals (not shown) that electrically connect various electronic components mounted on the printed circuit board and the battery pack 20 . In this embodiment, the battery pack attachment portion 21 is formed to recess in the exterior surface of the bottom portion of the main body unit 5 . When the battery pack 20 is attached to the battery pack attachment portion 21 as is shown in FIG. 1B , the exterior surface of the battery pack 20 is flush with the bottom surface of the main body unit 5 . [0033] The display portion 2 includes a case 9 , and the display screen 10 , a touch pad 11 , and a second click button 12 provided to the case 9 on the surface opposing the main body portion 1 , as well as a display processing unit (not shown) provided inside the case 9 and performing predetermined display processing. [0034] The display screen 10 is a screen on which to display various types of information, for example, characters and images. The touch pad 11 is an operation device used for an operation to move the cursor (pointer) displayed on the display screen 10 and an operation to scroll the display screen 10 . In this embodiment, a capacitance sensor is used as the touch pad 11 . [Internal Configuration of Information Processing Apparatus] [0035] The internal configuration of the information processing apparatus 100 of this embodiment will now be described with reference to FIG. 2 . FIG. 2 is a block diagram showing the hardware configuration of the information processing apparatus 100 . It should be appreciated, however, that FIG. 2 shows only a portion necessary for an inspection method of the battery pack 20 of this embodiment described below for ease of description. [0036] The information processing apparatus 100 includes a CPU 101 , a ROM (Read Only Memory) 102 , a RAM (Random Access Memory) 103 , the display portion 2 , the battery pack attachment portion 21 , and the battery pack 20 . The CPU 101 , the ROM 102 , the RAM 103 , the display portion 2 , and the battery pack attachment portion 21 are electrically interconnected via a bus 104 . Also, the battery pack 20 is connected to the CPU 101 , the ROM 102 , the RAM 103 , and the display portion 2 via the battery pack attachment portion 21 . [0037] The CPU 101 functions as an arithmetic processing unit and a controller. More specifically, the CPU 101 controls all or a part of operations by the information processing apparatus 100 according to various programs recorded, for example, in the ROM 102 or the RAM 103 . Accordingly, an inspection operation of the battery pack 20 by the information processing apparatus 100 of this embodiment described below is controlled by the CPU 101 . [0038] The ROM 102 stores programs, computation parameters, and the like used by the CPU 101 . Accordingly, an inspection program used for the inspection method of the battery pack 20 described below is also stored in the ROM 102 . The RAM 103 temporarily stores programs used when the CPU 101 performs predetermined processing and parameters necessary to run the programs. It should be noted that data, such as the programs and the computation parameters, is inputted in and outputted from any of the CPU 101 , the ROM 102 , and the RAM 103 via the bus 104 . [0039] Although it is not shown in the drawing, the battery pack attachment portion 21 has, for example, a detection portion detecting attachment of the battery pack 20 , a power charge and discharge terminal, and an information terminal via which information from and to a microcomputer in the battery pack 20 described below is inputted in and outputted from the main body portion 1 . Accordingly, when the battery pack 20 is attached to the battery pack attachment portion 21 , various types of monitor information (for example, a voltage and a temperature) measured by the battery pack 20 are outputted, for example, to the CPU 101 via the information terminal of the battery pack attachment portion 21 . [0040] It should be appreciated that the internal configuration (hardware configuration) of the information processing apparatus 100 described above is a mere example and the information processing apparatus 100 may be formed using general-purpose members as the respective components described above or may be formed of hardware specialized in functions corresponding to those furnished to the respective components. Hence, a hardware configuration to be used can be changed appropriately according to technical levels at which this embodiment is implemented. <2. Configuration of Battery Pack> [0041] FIG. 3 shows the internal configuration of the battery pack 20 used in the information processing apparatus 100 of this embodiment. The battery pack 20 includes a control board 23 on which a plurality of battery cell blocks 22 and a microcomputer 24 are mounted, and an input and output port 25 . [0042] Each battery cell block 22 is formed of a plurality of battery cells 30 (battery). In this embodiment, lithium-ion batteries are used as the battery cells 30 . In each battery cell block 22 , cathodes of a plurality of the battery cells 30 are connected together at a positive electrode 31 and anodes at a negative electrode 32 . In short, a plurality of the battery cells 30 are connected in parallel in each battery cell block 22 . It should be noted that the number of the battery cells 30 forming each cell block 22 can be set, for example, according to intended use. Hence, each cell block 22 may be formed of only one battery cell 30 depending on intended use. Also, the type of the battery cells 30 is not limited to a lithium-ion battery and the type can be also changed, for example, to suit intended use. [0043] In the battery pack 20 of this embodiment, a plurality of the battery cell blocks 22 are disposed in line so that the cathodes (or anodes) of the battery cells 30 are oriented in the same direction and the negative electrode 32 of one battery cell block 22 and and the opposing positive electrode 31 of the adjacent battery cell block 22 are electrically connected to each other. In short, a plurality of the battery cell blocks 22 are connected in series in the battery pack 20 . [0044] Also, in the battery pack 20 of this embodiment, each of the positive electrode 31 and the negative electrode is connected in parallel to the microcomputer 24 via a voltage detection line 33 . When connected in this manner, the microcomputer 24 becomes capable of measuring a voltage of each voltage cell block 22 . [0045] The microcomputer 24 (voltage information acquisition portion) is formed, for example, of an integrated circuit having, for example, a CPU and a ROM mounted on a single chip. The microcomputer 24 controls, for example, charge and discharge of the battery pack 20 when the battery pack 20 is attached to the main body portion 1 and measures, for example, a voltage and a temperature of each battery cell block 22 . Also, as will be described below, in this embodiment, even after the battery pack 20 is detached from the main body portion 1 and the operation mode shifts to a power saving mode, the microcomputer 24 acquires information for abnormal determination by measuring, for example, a voltage drop across each battery cell block 22 and an elapsed time since the detachment. [0046] The input and output port 25 is provided with terminals corresponding to the respective terminals provided to the battery pack attaching portion 21 . When the battery pack 20 is attached to the main body portion 1 , charge and discharge operations of the battery pack 20 and an output operation of information for abnormal determination (information on a voltage drop across the battery) are performed via the input and output port 25 . <3. Inspection Method of Battery Pack> [0047] An example of an inspection method of the battery pack 20 described above and the battery pack 20 of the information processing apparatus 100 including the same will now be described. [Principle of Inspection Method] [0048] In this embodiment, for example, abnormal events, such as an initial failure, an abnormal consumption current (capacitor leakage) of the control board 23 , poor welding of electrodes, poor soldering at the midpoint of a battery cell, entrance of foreign matter into the battery cell 30 (contamination), and breaking (perforation) of the battery cell 30 , are detected. [0049] Upon occurrence of abnormal events as above, for example, a voltage drop rate of one or both of the entire battery pack 20 and each battery cell block 22 or an unbalance amount of the voltage drop rate among the battery cell blocks 22 are increased. Hence, the abnormal events as above can be detected by measuring the voltage drop rate of one or both of the entire battery pack 20 and each battery cell block 22 . [0050] In a case where a voltage drop rate and an unbalance amount caused by the abnormal events as above are large, the abnormal events can be detected while the battery pack 20 is attached to the main body portion 1 . However, a voltage drop rate and an unbalance amount caused by the abnormal events other than an initial failure are normally so small that influences of charge and discharge make it difficult to detect the abnormal events while the battery pack 20 is attached to the main body portion 1 . In addition, influences of the abnormal events are substantially negligible at the time of shipping but become more significant with an increasing number of charge cycles and may possibly develop into a quite serious trouble. [0051] Such being the case, in order to detect abnormal events causing only a slight variance as described above, this embodiment is configured to measure a voltage of the battery pack 20 and a variance thereof while the battery pack 20 is in an unloaded condition (condition where the battery pack 20 is neither charged nor discharged) and also to perform an abnormal detection on the basis of the measurement result. This configuration makes it possible to detect the abnormal events described above that are otherwise difficult to detect while the battery pack 20 is attached to the main body portion 1 . [0052] In the following, the principle of the inspection method of the battery pack 20 of this embodiment will be described more concretely. In this embodiment, the battery pack 20 is detached from the main body portion 1 first to bring the battery pack 20 in an unloaded condition. Thereafter, information on a voltage drop across the battery cells 30 is automatically measured and recorded by the microcomputer 24 in a state, for example, where a voltage drop across the battery pack 20 stays at substantially a constant level or becomes more stable. In this embodiment, as the information on a voltage drop across the battery cells 30 , a voltage of each battery cell block 22 and a variance thereof in an unloaded condition and an elapsed time since the detachment of the battery pack 20 are measured by the microcomputer 24 and the acquired information is recorded in an internal ROM of the microcomputer 24 . [0053] Subsequently, when the battery pack 20 is re-attached to the main body portion 1 , various types of data recorded in the battery pack 20 while it was detached are read on the side of the main body portion 1 to calculate a voltage drop rate ΔV/h of one or both of the entire battery pack 20 and each battery cell block 22 while the battery pack 20 was detached. The CPU 101 in the main body portion 1 then determines the presence or absence of an abnormality in the battery pack 20 on the basis of the calculation result. [0054] It should be noted that a lithium-ion battery has a small self-discharge amount. Hence, in a case where lithium-ion batteries are used as the battery cells 30 as in this embodiment, there is a relatively large difference between a voltage drop rate at a normal time and a voltage drop rate at the occurrence of an abnormality in an unloaded condition and the abnormal events described above can be detected more easily. [Concrete Example of Inspection Method] [0055] A concrete example of the inspection method of the battery pack 20 of this embodiment will now be described with reference to FIG. 4 . FIG. 4 is a flowchart depicting the procedure of the inspection method of the battery pack 20 carried out in this embodiment. [0056] The inspection method of the battery pack 20 described below is mainly carried out between after the manufacturing of the battery pack 20 and an inspection of the main body before shipment. Accordingly, a defective battery pack 20 can be rejected at a high degree of accuracy before shipment. Safety of the information processing apparatus 100 can be thus improved. It should be appreciated, however, that the present invention is not limited to this configuration. The inspection described below may be conducted automatically after shipment of the information processing apparatus 100 to notify the user of an abnormality of the battery pack 20 in the event of an abnormality by displaying a message informing the presence of an abnormality on the display portion 2 . [0057] Initially, the battery pack 20 is detached from the main body portion 1 (Step S 1 ). It should be noted that Step S 1 is not performed immediately after the completion of manufacturing of the battery pack 20 . When the battery pack 20 is brought into a detached condition, the microcomputer 24 shifts to a power saving mode (sleep condition) (Step S 2 ). [0058] When ten minutes (first time) have elapsed since the battery pack 20 was brought into a detached condition, the microcomputer 24 measures a voltage Vout of each cell block 22 and stores the voltage Vout in an internal ROM of the microcomputer 24 as an initial voltage Vout (first voltage) while the battery pack 20 was detached. In this instance, the microcomputer 24 starts to count an elapse time Tout (hereinafter, referred to as the detachment time Tout) since detachment of the battery pack 20 (Step S 3 ). Further, in Step S 3 , the initial voltage Vout is recorded as an initial value of an attachment voltage Vin of each battery cell block 22 used in abnormal determination made when the battery pack 20 is re-attached to the main body portion 1 next time. [0059] The reason why a voltage of each battery cell block 22 is measured after ten minutes since the detachment of the battery pack 20 in Step S 3 is because a voltage fluctuation of each battery cell block 22 is relatively large immediately after the detachment of the battery pack 20 . A voltage fluctuation of each battery cell block 22 becomes stable after an elapse of about ten minutes since the detachment of the battery pack 20 . The voltage value after ten minutes since the detachment of the battery pack 20 is therefore used as the initial voltage Vout in a detachment state. It should be appreciated, however, that a time at which to measure the initial voltage Vout is not limited to after ten minutes since the detachment of the battery pack 20 . For example, the time can be changed to suit the type of the battery cells 30 , the cell block configuration, and the intended use. [0060] Subsequently, the microcomputer 24 determines whether ten minutes have elapsed since the counting of the detachment time Tout was started (Step S 3 ) or the detachment time Tout was updated (Step S 5 described below)(Step S 4 ). [0061] When ten minutes have elapsed since the counting of the detachment time Tout was started (Step S 3 ) or the detachment time Tout was updated (Step S 5 described below) in Step S 4 , “YES” is determined in Step S 4 . In this case, the microcomputer 24 measures a voltage of each battery cell block 22 and defines the measured voltage as the attachment voltage Vin. The microcomputer 24 further adds ten minutes to the detachment time Tout (Tout=Tout+10 [min]) (Step S 5 ). In short, the microcomputer 24 updates the attachment voltage Vin and the detachment time Tout in Step S 5 . After the processing in Step S 5 , the flow returns to Step S 4 and determination processing in Step S 4 is repetitively carried out. [0062] Meanwhile, in a case where ten minutes have not elapsed since the counting of the detachment time Tout was started (Step S 3 ) or the detachment time Tout was updated (Step S 5 ) in Step S 4 , “NO” is determined in Step S 4 . In this case, the microcomputer 24 determines whether the battery pack 20 is attached to the main body portion 1 (Step S 6 ). [0063] In a case where the battery pack 20 is not attached to the main body portion 1 in Step S 6 , “NO” is determined in Step S 6 . In this case, the flow returns to Step S 4 and the microcomputer 24 repeats the processing in and after Step S 4 described above. [0064] Meanwhile, in a case where the battery pack 20 is attached to the main body portion 1 in Step S 6 , “YES” is determined in Step S 6 . In this case, the microcomputer 24 records the attachment voltage Vin (second voltage) of each battery cell block 22 and the detachment time Tout (predetermined time), both of which are updated in Step S 5 most recently (second time), into an internal ROM of the microcomputer 24 . Further, in this instance, the microcomputer 24 records the initial voltage Vout measured in Step S 3 in the internal ROM of the microcomputer 24 . More specifically, the microcomputer 24 records a data set (information on a voltage drop across the battery) made up of the latest attachment voltage Vin and detachment time Tout of each battery cell block 22 as well as the initial voltage Vout, all of which are measured while the battery pack 20 was detached, in the internal ROM of the microcomputer 24 (Step S 7 ). [0065] Subsequently, the microcomputer 24 reads out a data set for abnormal determination used when the battery pack 20 was attached last time (a data set in which the detachment time Tout is the maximum (Tout_max)) from the internal ROM of the microcomputer 24 . The microcomputer 24 then compares the maximum detachment time Tout_max in the read data set for abnormal determination with the detachment time Tout in the data set recorded in Step S 7 upon attachment this time (Step S 8 ). [0066] In a case where the detachment time Tout in the data set recorded upon attachment this time is as long as or shorter than the maximum detachment time Tout_max in Step S 8 , “NO” is determined in Step S 8 and the flow proceeds to processing in and after Step S 10 described below. [0067] Meanwhile, in a case where the detachment time Tout in the data set recorded upon attachment this time is longer than the maximum detachment time Tout_max in Step S 8 , “YES” is determined in Step S 8 . In this case, the microcomputer 24 records the data set recorded in Step S 7 upon attachment this time into the internal ROM of the microcomputer 24 as the data set for abnormal determination of the battery pack 20 (Step S 9 ). In short, the microcomputer 24 updates the data set for abnormal determination of the battery pack 20 in Step S 9 . [0068] The reason why the data set in which the detachment time Tout is the maximum is used as the data set for abnormal determination of the battery pack 20 is because a voltage drop across the battery cell 30 is detected more easily when the detachment time Tout is longer and an abnormality is therefore detected in a more reliable manner. [0069] Subsequently, the CPU 101 (abnormal determination portion) of the main body portion 1 runs an inspection program of the battery pack 20 and reads out the data set for abnormal determination updated in Step S 9 from the battery pack 20 . The CPU 101 then calculates a voltage drop rate ΔV/h of each battery cell block 22 and a voltage drop rate ΔV_all/h of the entire battery pack 20 in accordance with the following equation (Step S 10 ). [0000] ΔV/h=(Vout−Vin)/(Tout_max) [0000] ΔV_all/h=(Vout_all−Vin_all)/(Tout_max) [0070] Where Vout_all in the equation is an initial voltage of the entire battery pack 20 calculated by adding up the initial voltage Vout of each battery cell block 22 in the data set for abnormal determination, and Vin_all is an attachment voltage of the entire battery pack 20 calculated by adding up the attachment voltage Vin of each battery cell block 22 in the data set for abnormal determination. [0071] Subsequently, the CPU 101 determines the presence or absence of an abnormality in the battery pack 20 on the basis of one or both of the voltage drop rate ΔV/h of each battery cell block 22 and the voltage drop rate ΔV_all/h of the entire battery pack 20 it has calculated (Step S 11 ). More specifically, for example, the CPU 101 compares the voltage drop rate ΔV_all/h of the entire battery pack 20 with a determination threshold (for example, 1 [mV/h]) of the voltage drop rate ΔV_all/h pre-stored in the ROM 102 . [0072] In a case where the calculated voltage drop rate ΔV_all/h is equal to or below the determination threshold in Step S 11 , the CPU 101 determines the absence of an abnormality in the battery pack 20 . In this case, “NO” is determined in Step S 11 and the inspection of the battery pack 20 is ended. [0073] Meanwhile, in a case where the calculated voltage drop rate ΔV_all/h is above the determination threshold in Step S 11 , the CPU 101 determines the presence of an abnormality in the battery pack 20 . In this case, “YES” is determined in Step S 11 and the abnormality in the battery pack is notified to the user, for example, via the display portion 2 (Step S 12 ). It should be noted that the determination using the voltage drop rate ΔV_all/h of the entire battery pack 20 as above makes it possible to detect an abnormality, for example, a consumption current abnormality of the control board 23 and breaking of the battery cell 30 . [0074] Further, the CPU 101 compares, for example, the voltage drop rates ΔV/h of the respective battery cell blocks 22 in Step S 11 . [0075] In this instance, in a case where differences of the voltage drop rate ΔV/h among the battery cell blocks 22 are equal to or smaller than a predetermined threshold, the CPU 101 determines the absence of an abnormality in the battery pack 20 . In this case, “NO” is determined in Step S 11 and the inspection of the battery pack 20 is ended. [0076] Meanwhile, in a case where the differences of the voltage drop rates ΔV/h among the battery cell blocks 22 are larger than the threshold, the CPU 101 determines the presence of an abnormality in the battery pack 20 . In other words, in a case where there is a battery cell block 22 having a voltage drop rate ΔV/h larger than the predetermined threshold in comparison with the other battery cell blocks 22 , the CPU 101 determines the presence of an abnormality in the battery pack 20 . In this case, “YES” is determined in Step S 11 and the CPU 101 notifies the user of the abnormality in the battery pack 20 , for example, via the display portion 2 (Step S 12 ). It should be noted that the comparison determination of the voltage drop rates ΔV/h of the respective battery cell blocks 22 makes it possible to detect an abnormality of cell balance due to influences, for example, of poor welding of electrodes, poor soldering at the midpoint of the battery cell, and entrance of foreign matter (metal) during the manufacturing of the battery cell 30 . [0077] In this embodiment, an abnormality in the battery pack 20 is detected as described above. It is preferable to conduct an abnormal inspection of the battery pack 20 for a battery pack 20 that has been charged to some extent. To be more concrete, it is preferable to apply the inspection method to a battery pack 20 having a remaining filling amount within a region in which a voltage linearly drops with a decrease in remaining charge amount according to the discharge characteristic of the battery pack 20 . Using such a battery pack 20 can lessen a variance of the voltage drop rate calculated in the inspection method. [0078] As has been described, according to the inspection method of this embodiment, the battery pack 20 is brought into an unloaded condition and a voltage of the battery pack 20 and a variance thereof during the unloaded condition are measured by the microcomputer 24 in the battery pack 20 to detect an abnormality on the basis of the measurement result. Hence, in this embodiment, besides abnormal events detectable in the related art, the battery pack 20 is capable of detecting various abnormal events causing a slight variance that have been difficult to detect during charge and discharge cycles. Further, by applying the inspection method of this embodiment to the battery pack 20 before shipment, it becomes possible to supply a higher quality battery back 20 to the market. [0079] In addition, because various abnormal events causing a slight variance as described above are detected by the inspection method of this embodiment, it is not necessary, for example, to provide special equipment or to make a circuit change. In other words, according to the battery pack 20 and the inspection method thereof of this embodiment, it becomes possible to detect, using a simpler configuration, an abnormal cause of the battery pack 20 that has been difficult to detect and thereby to further improve safety of the battery pack 20 . [Various Modifications] [0080] The procedure of the inspection method of the battery pack 20 according to the embodiment of the present invention is not limited to the example described above with reference to FIG. 4 and can be modified as follows. It should be appreciated that the same advantages as the embodiment described above can be achieved by respective modifications described below. [0081] According to the inspection method of the embodiment above, Step S 4 in which to determine the count time is performed before Step S 6 in which to determine attachment or detachment of the battery pack 20 . The present invention, however, is not limited to this configuration. For example, the determination processing in Step S 6 may be performed before the determination processing in Step S 4 . [0082] Also, according to the inspection method of the embodiment above, processing to calculate a voltage drop rate (Step S 10 ) is performed immediately before the abnormal determination processing (Step S 11 ). The present invention, however, is not limited to this configuration. The processing to calculate a voltage drop rate can be performed at any timing before Step S 11 . For example, the voltage drop rate ΔV/h of each battery cell block 22 and the voltage drop rate ΔV_all/h of the entire battery pack 20 may be calculated when the data set is recorded into the internal ROM of the microcomputer 24 in Step S 7 of FIG. 4 . In other words, the data set for abnormal determination may contain the voltage drop rate ΔV/h of each battery cell block 22 and the voltage drop rate ΔV_all/h of the entire battery pack 20 . [0083] The inspection method of the embodiment above has described a case where a data set containing the maximum detachment time Tout_max is constantly used as the data set for abnormal determination. The present invention, however, is not limited to this configuration. For example, the latest data set recorded in Step S 7 of FIG. 4 may be directly used as the data set for abnormal determination each time the battery pack 20 is reattached. In this case, the comparison determination processing of detachment time Tout (Step S 8 of FIG. 4 ) and update processing of the data set for abnormal determination (Step S 9 of FIG. 4 ) can be omitted. The inspection method therefore becomes further simpler. [0084] According to the inspection method of the embodiment above, in the comparison determination of the detachment time Tout (Step S 8 of FIG. 4 ), the flow proceeds to the processing in and after Step S 10 in a case where the detachment time Tout in the data set recorded upon attachment this time is as long as or shorter than the maximum detachment time Tout max. The present invention, however, is not limited to this configuration. In a case where “NO” is determined in Step S 8 , because data inspected in the past is used as the data set for abnormal determination, the inspection result in the past using this data set is known. Hence, in a case where “NO” is determined in Step S 8 and an abnormality is absent in the inspection result in the past, the inspection may be ended after Step S 8 . [0085] According to the inspection method of the embodiment above, the detachment time Tout is used in Step S 8 of FIG. 4 . However, a voltage drop amount ΔV (ΔV_all) may be used instead for the comparison determination so that a data set containing the maximum voltage drop amount is constantly used as the data set for abnormal determination. [0086] The inspection method of the embodiment above has described a case where processing in Step S 10 of FIG. 4 in which to calculate the voltage drop rate and thereafter is carried out by the main body portion 1 . The present invention, however, is not limited to this configuration. [0087] For example, all the processing in FIG. 4 may be carried out by the microcomputer 24 in the battery pack 20 . In this case, for example, a warning lamp or the like is provided to the battery pack 20 and the warning lamp is lit in the event of an abnormality in the battery pack 20 . [0088] Alternatively, the comparison determination processing of the detachment time Tout (Step S 8 ) of FIG. 4 and processing thereafter may be carried out by the CPU 101 of the main body 1 . It should be noted, however, that when a different battery pack 20 is attached, because the characteristic of the battery pack 20 differs from one to another even the type is the same, it is necessary in this case to perform processing that suits the attached battery pack 20 . To this end, it is preferable to include information (for example, ID information) to individually identify the attached battery pack 20 in the data set for abnormal determination. [0089] The inspection method of the embodiment above has described a case where the voltage drop rate ΔV/h(ΔV_all/h) is used as a parameter for abnormal determination in Step S 11 of FIG. 4 . The present invention, however, is not limited to this case. For example, the voltage drop amount ΔV(ΔV_all) may be used as a parameter for abnormal determination. [0090] The inspection method of the embodiment above has described a case where both the voltage drop rate ΔV/h of each battery cell block 22 and the voltage drop rate ΔV_all/h of the entire battery pack 20 are used for abnormal determination in Step S 11 of FIG. 4 . The present invention, however, is not limited to this case. For example, either one of these voltage drop rates alone may be used depending on intended use. [0091] The inspection method of the embodiment above has described a case where information on a voltage drop across the battery cell 30 is acquired by the microcomputer 24 while the battery pack 20 is in a state (unloaded condition) where the battery pack 20 is detached from the main body portion 1 . The present invention, however, is not limited to this case. For example, in a case where the main body portion 1 is furnished with the function of inhibiting charge and discharge of the battery pack 20 even when the battery pack 20 is attached to the main body portion 1 , the inspection method of the embodiment above is applicable. In addition, even in a case where power consumption of the battery pack 20 is constant with respect to time while the battery pack 20 is attached to the main body portion 1 , because a voltage drop across the battery pack 20 becomes constant, the inspection method of the embodiment above is applicable, too. [0092] In a case where the inspection method of the embodiment above is used while the battery pack 20 is attached to the main body portion 1 , information on a voltage drop across the battery cell 30 may be acquired by the microcomputer 24 in the battery pack 20 or, for example, by the main CPU on the side of the main body portion 1 . In other words, in a case where the inspection method of the embodiment above is carried out while the battery pack 20 is attached to the main body portion 1 , the voltage information acquisition portion that acquires information on a voltage drop across the battery cell 30 may be provided on the side of the main body portion 1 (on the outside of the battery pack 20 ). [0093] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
A battery pack includes: a chargeable and dischargeable battery; and a microcomputer that acquires information on a voltage drop across the battery in a condition equivalent to no load and stores the information therein.
6
CROSS REFERENCE TO RELATED APPLICATIONS This application is the US National Stage of International Application No. PCT/EP2009/050614, filed Jan. 21, 2009 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 08003487.9 EP filed Feb. 26, 2002. All of the applications are incorporated by reference herein in their entirety. FIELD OF INVENTION The invention relates to a device for the nondestructive material testing of an at least sectionally solid test subject by applying ultrasonic waves to the test subject and detecting the ultrasonic waves reflected inside the test subject, according to the claims. BACKGROUND OF INVENTION In the case of many objects which are fully or partially formed solidly, their internal structure needs to be examined for material defects. To this end, nondestructive testing methods are required in order to obtain information about the internal structure which cannot be seen. This is necessary in particular for components subjected to heavy mechanical stress. For example, steel components are forged after casting in order subsequently to be brought into their final shape by turning or other cold treatments. In this case, the testing for internal material defects may be carried out directly after forging. Such components which are already in use must also be subjected regularly to material testing. This applies in particular to components which are exposed to heavy loads. The component to be tested may, for example, be a turbine blade for a gas or steam turbine. The turbine blade roots, in particular, are exposed to heavy loads during operation. These loads may lead to cracks, which can be detected and located with the ultrasonic measurement method by scanning the surface. Since the surface has a complex geometry, special measurement methods are necessary. Conventionally, such metal parts are tested using ultrasound. In this case, the sound waves which are reflected at interfaces inside the metal part are detected. With the time of flight of the reflected sound wave it is possible to detect, and from this the path length travelled and therefore the distance can be determined. By applying sound from different directions, further information can be obtained about the material defect or defects. From this, material defects can be located. For example, the geometrical orientation of the material defect can be determined in this way. From the shape of the reflected sound waves, deductions can be made about the type of material defect. By scanning the surface of the test subject using an ultrasonic detector and recording the acquired data, the volume accessible to the ultrasound can be examined fully. From the acquired data, it is possible to generate an image which can be used for assessment. In one known method, shaped parts are manufactured, for example from casting resin. These shaped parts can be applied with an accurate fit onto the surface to be scanned. The shaped parts contain holes into which an ultrasonic testing head is inserted. In order to be able to scan the entire surface to be tested, the ultrasonic testing head is displaced manually by discrete distances. This, however, is very laborious. In another known method, the ultrasonic testing head is located on a carriage which is applied by means of a holding device on a neighboring test subject. The holding device can be moved by means of motors over the surface to be scanned. The testing head is pressed onto the surface of the test subject by springs. Optimal orientation of the testing head, however, is not possible in this case. SUMMARY OF INVENTION It is an object of the invention to provide a device for the nondestructive material testing of an at least sectionally solid test subject, of the type mentioned in the introduction, with which the possibilities for positioning the testing head are improved and the outlay on measurement technology is reduced. This object is achieved by the subject-matter according to the claims. According to the invention, the device mentioned in the introduction has the following components: at least one testing head for transmitting the ultrasonic waves and for detecting the ultrasonic waves reflected from the test subject, at least one mobile carriage, on which the testing head is attached or can be attached, an elongate rail for guiding the carriage, which is adapted or can be adapted to the structure of the surface of the test subject, wherein the carriage can be moved along the rail. The testing head is arranged so that it can be moved relative to the carriage, which achieves at least one further degree of freedom for the movement of the testing head. The essential point of the invention is that the carriage can be moved along a rail, and the rail can be applied onto the surface of the test subject. The rail in this case extends along a predetermined path on the surface of the test subject, and the carriage can be moved along this path. The carriage can be positioned at any desired location along the rail. The carriage can therefore be moved continuously along the rail. Preferably, the rail is produced or can be produced by means of a stereolithography method. In this way, the rail can be produced, and adapted to the surface of the test subject, merely with the aid of a drawing of the surface of the test subject. The rail can therefore be adapted even to particularly complex surfaces. According to the preferred embodiment, the rail is produced or can be produced from at least one material which can be cured by a treatment with ultraviolet light. The rail therefore initially consists of a flexible material and is correspondingly deformable. The rail can subsequently be cured in the desired shape. In this way, a matching rail and therefore a suitable testing device can be provided very rapidly for a particular test subject. For example, the rail is produced or can be produced from at least one epoxy resin. In particular, the rail has one or more guiding grooves and/or guiding channels, which are formed complementarily to the carriage or are formed as a section of the carriage. This contributes to accurate guiding of the carriage in the rail. Furthermore, the carriage may have at least one guiding roller. This allows low-friction, accurate movement of the carriage within the rail. Preferably, at least one guiding roller and at least one guiding channel or guiding groove are engaged with one another or can be brought to engage with one another. The possibility for moving the carriage is therefore defined uniquely, i.e. along the rail. According to the preferred embodiment, the carriage has at least one motor for driving the carriage along the rail. To this end, the carriage may have at least one gear wheel or the like coupled to the motor, which engages or can be brought to engage with the rail with a force fit. This creates a unique relationship between the number of full revolutions of the motor and the position of the carriage. Furthermore, the rail may have at least one gear rack. As an alternative or in addition, at least one set of gear teeth may be formed in or on the rail. In this case, the gear wheel may engage or be brought to engage with the gear rack or the gear teeth. This leads to slip-free movement of the carriage. Preferably, the testing head can be tilted on the carriage about an axis which extends parallel to the longitudinal axis of the rail. In this way, the detection region can be optimized with two degrees of freedom for the movement of the testing head. Furthermore, the testing head and the carriage may be coupled to one another by at least one restoring apparatus. A stable position of the testing head can be defined and achieved in this way. For example, the restoring apparatus has at least two magnet elements interacting with one another. As an alternative or in addition, the restoring apparatus may have at least one spring element. Furthermore, at least two guiding rollers may be attached on the carriage in a mutually mobile fashion, so that the positions of the guiding rollers can be adapted to the profile of the rail. The effect which can be achieved by this is that the shape of the carriage is adapted to the rail in a simple way. Preferably, the carriage comprises at least two frame parts which are connected or can be connected to one another in a tiltable fashion, at least one guiding roller being fastened rotatably on each part. In this case, the at least two frame parts may be tiltable about an axis which extends along the movement direction of the carriage. This allows particularly simple adaptation of the shape of the carriage to the profile of the rail. For example, two guiding rollers are arranged next to one another on at least one frame part. In this case, this frame part with the two guiding rollers forms a rigid axle which can be tilted with respect to the upper frame part. In the preferred embodiment, two guiding rollers are respectively arranged next to one another on at least two frame parts, so that the axles respectively having two guiding rollers can be tilted relative to one another. For the coupling of the frame parts, the at least two frame parts may also be coupled to one another by at least one restoring apparatus. For example, the restoring apparatus comprises at least two magnet elements interacting with one another. As an alternative or in addition, the restoring apparatus may have at least one spring element. Furthermore, the device may have at least one control apparatus. The control apparatus may control both the transmission and the detection of the ultrasonic waves. Furthermore, the movement of the testing head and/or the carriage may also be controlled by the control apparatus. In the preferred embodiment, the device is provided for the material testing of a test subject made of metal, and in particular for the material testing of a forged component. The device is particularly suitable for the material testing of a turbine wheel, a turbine wheel blade or a turbine wheel blade root. The dependent claims relate to other features, advantages and particular embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The method according to the invention will be explained in more detail below in the description of the figures with the aid of preferred embodiments and with reference to the appended drawings, in which: FIG. 1 shows a schematic perspective view of a carriage for a device for the nondestructive material testing of a test subject according to a preferred embodiment of the invention, FIG. 2 shows a schematic perspective view of a rail for the device for the nondestructive material testing of the test subject according to the preferred embodiment of the invention, FIG. 3 shows a detailed perspective view of the rail for the device for the nondestructive material testing of the test subject according to the preferred embodiment of the invention, and FIG. 4 shows a schematic perspective exploded view of the carriage with a testing head according to the preferred embodiment of the invention. DETAILED DESCRIPTION OF INVENTION FIG. 1 shows a schematic perspective view of a carriage 14 for a device for the nondestructive material testing of a test subject according to a preferred embodiment of the invention. The carriage 14 is formed essentially as a rectangular frame. The carriage 14 comprises a plurality of individual parts, most of which are made of plastic. On each of the two outer longitudinal sides 16 of the carriage 14 , there are respectively two guiding rollers 18 . The guiding rollers 18 are fastened on the carriage 14 so that they can rotate. In particular, the guiding rollers 18 are fastened on the rectangular frame so that they can rotate. In this specific embodiment, the guiding rollers 18 are made of metal. The rectangular frame is formed in two parts in this exemplary embodiment, as will be described in more detail below. On one of the two longitudinal sides 16 , there is a gear wheel 20 above the guiding rollers 18 . The gear wheel 20 is likewise applied on this longitudinal side 16 so that it can rotate. The gear wheel 20 is furthermore configured as a drive wheel, and is driven by an electric motor 21 . The carriage 14 is intended to accommodate at least one testing head, which is not represented explicitly in FIG. 1 . The carriage 14 essentially comprises the rectangular frame and a reception apparatus 30 for the testing head. The reception apparatus 30 for the testing head is applied by means of a restoring apparatus in the rectangular frame. The testing head is intended to transmit the ultrasonic waves and to detect the ultrasonic waves reflected by the test subject. In the preferred embodiment, the testing head is applied on the carriage 14 so that it can be tilted. For example, the tilt axis extends parallel to the movement direction of the carriage 14 . In the preferred embodiment, the carriage 14 has a restoring apparatus, so that the testing head can be tilted automatically into a predetermined position, in particular into a central position. The restoring apparatus may have magnet elements or spring elements. FIG. 2 represents a schematic perspective view of a rail 22 for the device for the nondestructive material testing of the test subject according to the preferred embodiment of the invention. In this preferred embodiment, the rail 22 is made of epoxy resin. The rail 22 can therefore be cured by a treatment with ultraviolet light. Furthermore, the rail 22 is preferably produced by means of a stereolithography method. This allows the rail to be produced merely with the aid of a drawing of the surface of the test subject. The rail 22 is configured as an elongated rectangular frame. The contour of the rail 22 is adapted to the surface of the test body, so that one of the two large-area sides is formed essentially complementarily to the surface of the test subject and faces towards the test subject during the material testing. On each of the two inner longitudinal sides 24 , there is respectively a guiding channel 26 . The two guiding channels 26 extend parallel to the longitudinal axis of the rail 22 , with the two open sides of the guiding channels 26 facing towards one another. The guiding channels 26 are therefore open towards the inside. The rail 22 furthermore comprises a set of gear teeth 28 , which extend in a similar way to a gear rack along the longitudinal axis of the rail 22 . The rail 22 and the carriage 14 are adapted to one another in respect of their geometry so that the carriage 14 can be displaced inside the rail 22 . The guiding rollers 18 of the carriage 14 can in this case move in the guiding channels 26 of the rail 22 , and the gear wheel 18 of the carriage 14 is engaged with the gear teeth 28 . FIG. 3 shows a detailed perspective view of the rail 22 for the device for the nondestructive material testing of the test subject according to the preferred embodiment of the invention. FIG. 3 illustrates some details of the rail 22 . The guiding channels 26 are located on the two inner longitudinal sides 24 . The two guiding channels 26 are also parallel to one another. The distance between the guiding channels 26 is essentially constant. The guiding channels 26 are open towards the inside, and their open sides faced towards one another. The set of gear teeth 28 is configured and arranged so that the gear wheel 20 engages with the gear teeth 28 and at the same time the guiding rollers 18 engage with the corresponding guiding channels 26 . FIG. 4 shows a schematic perspective exploded view of the carriage 14 with a testing head 36 according to the preferred embodiment of the invention. The carriage 14 comprises the rectangular frame, which in turn has a first frame part 32 and a second frame part 34 . The reception apparatus 30 for the testing head 36 is provided inside the first frame part 32 . The testing head 36 is in turn provided inside the reception apparatus 30 . The drive wheel, configured as a gear wheel 20 , is driven by the electric motor 21 . Two guiding rollers 18 , lying next to one another, are applied on the first frame part 32 . Two further guiding rollers 18 , lying next to one another, are applied on the second frame part 34 . The first frame part 32 and the second frame part 34 are connected or can be connected to one another so that they can be tilted along the longitudinal axis of the carriage 14 . The two axles of the guiding rollers 18 can therefore be tilted with respect to one another, so that the carriage 14 can be adapted to the profile of the rail 22 . Owing to the tilting of the axles, all four guiding rollers 18 are always in contact with the rail 22 . The carriage 14 comprises a multiplicity of magnet elements 40 , which form two restoring apparatuses. One restoring apparatus acts between the reception apparatus 30 and the first frame part 32 . A further restoring apparatus acts between the first frame part 32 and the second frame part 34 . On the reception apparatus 30 , on the first frame part 32 and on the second frame part 34 , there are holes 42 which are intended to accommodate the magnet elements 40 . The holes 42 are slightly larger than the corresponding magnet elements 40 . The reception apparatus 30 can be tilted with respect to the first frame part 32 in two directions perpendicularly to the movement direction of the carriage 14 , and can be restored automatically into a central position by means of the restoring apparatus. The second frame part 34 can likewise be tilted with respect to the first frame part 32 , about the axis which extends parallel to the movement direction of the carriage 14 , and restored automatically into a central position by means of the restoring apparatus. In the central positions, the corresponding openings face one another exactly. The testing head can therefore on the one hand be moved along the rail 22 and on the other hand tilted perpendicularly to it, so that a comparatively large region can be exposed to sound and detected. Only two degrees of freedom of movement are required for the testing head, so that a relatively simple algorithm is sufficient for controlling the testing head and detecting and evaluating the reflected sound waves. The material testing is carried out by moving a testing head, which is applied on the carriage 14 , along the rail 22 and therefore along the outer surface of the test subject. The testing head can be tilted about an axis which is parallel to the longitudinal axis, and at least to the tangent of the rail 22 . With the device according to the invention, it is not absolutely necessary to scan the entire surface of the test subject in order to acquire the full volume of the test subject. A particular section or a particular path on the surface may for example be scanned, since owing to the tilting movements of the testing head at least the relevant region of the volume can be acquired even without full scanning of the surface.
A device for the nondestructive material testing of an at least sectionally solid test subject by applying ultrasonic waves to the test subject and detecting the ultrasonic waves reflected inside the test subject is provided The device includes at least one testing head for transmitting the ultrasonic waves and for detecting the ultrasonic waves reflected from the test subject, at least one mobile carriage, on which the testing head is attached, and an elongate rail for guiding the carriage, which is adapted to the structure of the surface of the test subject. To this end, the carriage may be moved along the rail.
6
This is a continuation of U.S. patent application No. 09/438,865 filed on Nov. 12, 1999, which issued as U.S. Pat. No. 6,452,989 and which is a continuation-in-part of Application No. 09/243,910 filed on Feb. 3, 1999, which issued as U.S. Pat. No. 6,154,501, and claims priority to Provisional Application No. 60/142,179 filed on Jul. 1, 1999. BACKGROUND OF THE INVENTION The invention relates to satellite communications systems generally, and more particularly to satellite communication systems which divide the transmitted signal, either in power or in content, to be synchronized and recombined in the receiving terminal. This concept applies readily to broadcast applications, but it is not so limited. The satellite industry has experienced a progression of performance enhancements evidenced by increased transmit power capability of satellite transponders, improved low-noise amplifier (LNA) characteristics, and smaller receiving antennas. In satellite systems with a large number of receiving stations, it is particularly important to reduce the cost of each receiving unit and to design a system with a small receiving antenna to meet installation and aesthetic requirements. The need for a small receiving antenna has motivated an increase in transponder power output in order to maintain an acceptable signal-to-noise ratio (SNR) with the smaller antenna. As satellite users move from lower power transponders to higher power transponders, falling demand for the lower power transponders reduces the cost of their use. Receiving a signal from a lower power transponder with the smaller receiving antenna size produces a received power at the LNA too low to maintain SNR requirements. The present invention permits the receiver to combine received signals from a plurality of transponders, possibly located on a plurality of satellites to enable again the use of lower power transponders, but with small receiving terminal antennas. SUMMARY OF THE INVENTION A satellite communications system includes a transmitting station that directs information-carrying signals toward an orbiting satellite, which receives the signals and in turn retransmits the signals on a different frequency band toward a plurality of receiving terminals. The satellite contains a transponder which receives signals as a broad band of frequencies and retransmits them on another set of frequencies of equal bandwidth but shifted to another location in the spectrum. The present invention has as its object a satellite communications system including a transmitting facility that divides the signal into a plurality of subchannels directed toward a plurality of transponders located on one or more satellites and a receiving terminal that receives the subchannels, time-synchronizes the subchannels, and combines them into a faithful replica of the original composite signal. The division of the signal into subchannels is carried out by one of two methods. In a first division method, the source signal is replicated across the plurality of transponders. Hereinafter the first division method is referred to as power-division. In a second division method, the content of the source signal is represented by a set of distinct subsignals, each of which subsignals contains less information as the original signal, but said distinct subsignals can be conveniently recombined in the receiver to reconstruct the original signal satisfactorily. Hereinafter this second division method is referred to as content-division. In a system using power-division to create subchannels, the originating transmitter directs more than one identical signal to a plurality of transponders, possibly located on a plurality of satellites. In said system, transponders retransmit and the receiving antenna system conducts all of the aforementioned signals into the receiving system. The receiving terminal provides means of time-synchronizing the plurality of received signals, adjusts the relative power level of the plurality of received signals to be approximately equal, and combines the signals into a composite via a signal adding process. Each of the signals added contains both an information component and a random noise component, such noise having been introduced primarily in the first amplifier of the receiver, typically a low-noise block converter (LNB). Those skilled in the art know that the information component of each signal will be statistically correlated, but the noise components will be statistically uncorrelated, both to each other and to the information component. Thus the information components will add linearly into the composite signal, that is in proportion to their number. The power in the information component of the composite signal will then be in proportion to the square of the number of received signals being added together. In contrast, the power in the noise component of the composite signal will be in proportion to the number of received signals added together. Thus the SNR of the composite signal is improved over the SNR of the individual subchannel signals by a factor of N in power, where N is the number of channels added together to form the composite signal. The foregoing discussion assumes that the signal levels and noise levels in each of the subchannel signals is identical. In a real system, transmission characteristics will vary slightly between subchannels, signal and noise levels being slightly different between subchannels, resulting in an SNR improvement ratio somewhat less than the factor of N described above. In any case, the receiver may require automatic means of adjusting the power of each of the signals to be added at the combining point so as to be approximately equal to each other in level. In a system using content-division to create subchannels, the originating transmitter directs distinct subsignals toward the plurality of transponders, the subsignals being created in such a way as to permit convenient reconstruction of the original signal at the receiving terminal. In an exemplary analog system, the original signal can be divided into sub-band signals using a filter-bank process. If the filters used satisfy quadraturemirror properties, the subsignals can be added directly to reproduce the original signal without phase distortion at the boundary frequencies. If the analog signal contains a strong periodic timing component (as does a television signal), this periodic timing component can be separated from the remainder of the signal before dividing the signal into sub-band components. Said timing component could then be added back to each of the sub-band components to produce subchannel signals with different frequency components, but common timing information. This strategy naturally provides timing information useful to facilitate the necessary time-resynchronizing process in the receiver. As above, in a system using content-division to create subchannels, the originating transmitter directs distinct subsignals toward the plurality of transponders, the subsignals; being created in such a way as to permit convenient reconstruction of the original signal at the receiving terminal. In an exemplary digital system, the original binary signal can be divided into subchannel digital signals, each of which has a bit rate less than the original digital signal. The original digital signal can be divided into subchannel digital signals in any number of ways. Two simple exemplary digital subchannel strategies are as follows. A first exemplary digital subchannel strategy is to direct each successive bit into each subchannel sequentially. A second exemplary digital subchannel strategy is to direct each fixed-size block of bits in the original signal to each successive subchannel sequentially. This second exemplary strategy fits well with digital source signals that are organized in a fixed-blocksize structure in the original signal as in Digital Video Broadcast (DVB) for example. In the case that a plurality of satellites is used to conduct a set of subchannels from a transmitting station to a given receiving terminal, each subchannel will generally experience a different propagation delay. The instant invention provides means to determine the amount of time to delay each subchannel in order to combine them synchronously. The delay required for each received subchannel will in the general case differ. The present invention provides additional means to implement the aforedetermined delay for each subchannel independently. The receiving terminal system, when activated for a particular virtual channel, determines the relative delay between the subchannel signals arriving at the receiver. This could be accomplished by correlating the subchannel signals with each other at all possible delays expected in a particular implementation of the system. As this process is very time consuming and source signal dependent, it is therefore subject to false synchronization and possible failure to synchronize at all, particularly if the source signal does not contain enough timing information. The present invention solves this problem by transmitting a timing signal along with the original signal. Some sources may by their nature guarantee adequate timing information to facilitate reliable synchronization. The timing signal described arrives at the receiving terminal via a plurality of propagation paths, each experiencing a different delay, the timing signal is being added to the virtual satellite system in such a way so as to be separable from the original signal on each subchannel. The receiving terminal then correlates timing signals arriving on different subchannels; to determine the amount of relative propagation delay. All subchannel signals contain common timing information to facilitate the correlation process. This guarantees that the subchannels can be processed and compared in a known way to determine relative propagation delay. The timing signal if required for synchronization can be added to the virtual satellite channel using one of two exemplary methods, but the instant invention is not so limited. A first exemplary method requires that a narrow bandwidth signal be transmitted across each satellite in the virtual channel. The narrow band signal requires a small allocation of the available spectrum, but provides a dedicated timing signal on each satellite actively carrying virtual satellite channels. The narrow band timing signal provides propagation delay information to virtual channel receiving terminals having one or more subchannels on the satellite. The timing signal could consist of one or more of the following exemplary signals, but the instant invention is not so limited. A first exemplary signal is a carrier modulated digitally by a binary pseudorandom noise sequence. A second exemplary signal is a periodic pulse. The pulse could be time-dispersed prior to transmission to create a signal with improved peak to average waveform properties. The receiving terminal in this example would reverse the time-dispersal process to recover a narrow-time pulse. The time period of either exemplary signal above described, after which the signal repeats, would be longer than twice the greatest expected delay difference between subchannels, thus facilitating unambiguous determination of propagation delay. A second exemplary method of incorporating a timing signal in the virtual satellite system consists of adding a spread spectrum component to each of the information-bearing subchannels in the system, and within the bandwidth of each subchannel. The magnitude of the spread spectrum timing component is much lower than the information signal so as not to reduce the performance of the normal receiver demodulation process. The spread spectrum signal is then de-spread in the receiving terminal, thereby increasing its magnitude above that of the information content. The increase in signal level is proportional to the processing gain. This process facilitates delay synchronization in the receiving terminal and has two advantages. A first advantage is that the second exemplary method does not increase the bandwidth requirements of the virtual channel to accommodate a timing signal. A second advantage is that the full bandwidth of the information channel is available to the timing signal resulting in high resolution relative delay estimation. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic and block diagram illustrating the present invention. FIG. 2 is a schematic and circuit block diagram of one embodiment of the present invention. FIG. 3 is a schematic and circuit block diagram of another embodiment of the present invention. FIG. 4 is a schematic and circuit block diagram of another embodiment of the present invention. FIG. 5 is a schematic and circuit block diagram of another embodiment of the present invention. FIG. 6 is a schematic and circuit block diagram of a multiple beam antenna embodiment of the present invention. DESCRIPTION OF THE INVENTION Referring now to the drawings in which like reference numerals indicate like or corresponding elements over the several views, FIG. 1 shows an overview of the satellite communications system consisting of subsystems 12 , 10 , 16 . Original signal 22 feeds subchannel divider 24 which separates the signal into a plurality of numbered subsignals. The exemplary system of FIG. 1 shows the number of subsignals to be four, but the present invention is not so limited. Subchannel divider 24 creates the subsignals by dividing original signal 22 employing one of two methods. A first method divides the signal on the basis of power. In this first method all the subchannel signals emerging from subchannel divider 24 are identical. A second method divides the signal on the basis of content. In this second method, each subchannel signal carries at least some information that is not carried by the other subchannels. The information content may be mutually exclusive or may overlap between subchannels, but in any case the subchannel signals under the second divider method are not identical as in the first method. Each subchannel signal feeds an uplink transmitter 26 a - 26 d , each of which uplink transmitters feeds a separate antenna 28 a - 28 d , directing radio frequency energy toward a plurality of orbiting satellites 14 a - 14 d via propagation paths 18 a - 18 d . Uplink transmitters 26 a - 26 d add timing signal 23 to the signal to be transmitted either on a separate frequency allocation or in the bandwidth of the information-bearing carrier. The exemplary system of FIG. 1 shows the number of satellites used by the system to be four, but the instant invention is not so limited. Each satellite 14 a - 14 d receives a band of frequencies, amplifies the signals received in that band, and retransmits the band at a different location in the spectrum. Each of said satellites has a transmitting antenna pattern that includes receiving terminal system 16 . Propagation paths 20 a - 20 d from each satellite 14 a - 14 d to representative receiving terminal 16 carry radio frequency energy from satellites 14 a - 14 d to the receiving terminal system 16 . It should be understood that although FIG. 1 depicts each uplink signal being carried by a different satellite, the present invention is not so limited. For example, transponders of satellites 14 a , 14 b could be collocated on the same satellite. In this case, uplink transmitters 26 a , 26 b and uplink antenna systems 28 a , 28 b could be combined, in addition to satellites 14 a , 14 b representing the same satellite. Propagation paths 18 a , 20 a , 18 b , 20 b in this case would be combined into single uplink and downlink propagation paths. Receiving terminal system 16 incorporates one of two antenna methods. A first method includes a plurality of antenna components to receive the plurality of satellite signals 20 a - 20 d . A second method incorporates a multiple beam antenna. The exemplary system of FIG. 1 uses multiple beam antenna 30 , but the present invention is not so limited. In either of the aforementioned receiving terminal antenna methods, the antenna subsystem produces a plurality of output signals corresponding to the subchannel signals emerging from subchannel divider 24 in uplink system 12 . In the exemplary system of FIG. 1 , each of the numbered signals emerging from multiple beam antenna 30 correspond to similarly numbered signals emitted by subchannel divider 24 . This signal identity remains true whether satellites 14 a , 14 b of FIG. 1 are distinct or represent the same satellite as indicated in the foregoing description. The subchannel signals emitted by multiple beam antenna 30 feed a plurality of tuners 32 which then drive a plurality of demodulators 34 . A signal emerging from one of the demodulators 34 then represents a version of the corresponding output of subchannel divider 24 , but delayed in time in proportion to the sum of the lengths of the corresponding uplink and downlink propagation paths 18 and 20 . In receiving terminal 16 , delay component 36 further delays first-arriving signals such that all the subchannel components arrive at subchannel combiner 38 at nearly the same time. Said combiner 38 produces a reconstruction 40 of original signal 22 . The method used in subchannel combiner 38 is consistent with and corresponds to the method used to divide original signal 22 in subchannel divider 24 . Digital Content-Division The instant invention uses one of four methods to perform the dividing and combining operations of subchannel divider 24 and subchannel combiner 40 . In each of said methods, subchannel divider 24 of FIG. 1 feeds a plurality of uplink transmitters 26 a - 26 d , but the signals emerging from subchannel divider 24 are different in nature depending of the dividing and combining method used. In a first dividing and combining method, original signal 22 is digital. In said first method, subchannel divider 24 divides said digital signal into lower data rate subchannel signals with binary content that contains at least some mutually exclusive information. The division could be on a sequential bit-by-bit basis, could be on a sequential frame-by-frame basis, and may or may not relate to possible framing in the original digital signal (e.g. DVB transport). The exemplary receiving terminal 16 of FIG. 2 depicts a two-subchannel digital receiving system where the radio frequency carriers feeding the demodulators 36 a and 36 b are quaternary phase shift keying (QPSK) modulated signals, but the present invention is not so limited. Said figure further indicates the use of a multiple beam antenna 30 , but the present invention is not so limited. Referring again to FIG. 2 , multiple beam antenna 30 emits first and second signals into first and second tuners 32 a and 32 b . Each tuner shifts a band of higher frequencies to a band of lower frequencies of equal bandwidth such that receiver controller 42 sets the center frequency of the higher band, but the lower band is fixed. Tuners 32 a , 32 b emit QPSK modulated signals at a frequency that the QPSK demodulators 36 a , 36 b expect to receive. As there are two subchannels in the example of FIG. 2 , the data rate of the binary information contained in these QPSK signals is approximately half the data rate of original signal 22 . The respective outputs of QPSK demodulators 36 a , 36 b emit signals to bit detectors 38 a , 38 b which in turn produce streams of binary data corresponding to the subchannel division in uplink system 12 . Delay operators synchronize the data streams by introducing delay in the first-arriving binary stream such that there is a minimum of relative delay between the respective delay operator outputs. Digital content combiner 48 reverses the content division process of subchannel divider 24 so as to produce at its output a faithful delayed replica 50 of original digital signal 22 . Receiver controller 42 of FIG. 2 responds to user input (not depicted) to select the transponders 14 to combine, subsequently emitting control signals to multiple beam antenna 30 to direct its antenna patterns toward the satellites containing selected transponders 14 . Receiver controller 42 also selects each tuner frequency consistent with the signals emitted from the selected transponder. Receiver controller 42 further processes information from timing signal correlator 44 to determine the correct setting of delays 40 a , 40 b . Timing signal correlator 44 receives and time correlates tuner outputs 34 . For a system with more than two subchannels, correlator 44 processes tuner outputs in pairs to determine relative delay between subchannels. Nonvolatile memory 46 contains parameters regarding the user-selected transponders to enable the correct setting of multiple beam antenna 30 and tuners 32 . Digital Power-Division The instant invention can use a second method for transporting a digital signal across a virtual satellite channel. Referring to FIG. 3 which depicts an example of said second method which combines delayed demodulator outputs from identical subchannels as described previously as power combining. Under the direction of receiver controller 42 , multiple beam antenna 30 emits signals to tuners 32 a , 32 b which translate variable transponder bands into a fixed band of frequencies expected by the QPSK demodulators 54 . FIG. 3 depicts a receiving terminal using a multiple beam antenna, but the present invention is not so limited. FIG. 3 further depicts a receiving terminal with two subchannels, but the instant invention is not limited to two subchannels. The figure in addition shows the use of a QPSK modulation scheme, but the instant invention is not so limited. Subchannel signals 52 emitted by tuners 32 contain identical digital information transmitted at the full rate of original signal 22 . QPSK demodulators 54 produce soft decision outputs I A and Q A for each subchannel. Since the total propagation delay for each subchannel is in general different, first arriving soft decisions must be delayed in time by an amount such that soft decisions emitted by delays 56 emerge with nearly zero relative delay between subchannels. Delays 56 digitize the analog soft decisions produced by demodulators 54 , placing digitized results in a first-in first-out (FIFO) buffer. Receiver controller 42 controls the amount of time delay in delays 56 with input from timing signal processor 44 and digital correlator 58 . Timing signal processor 44 analyzes input from tuner outputs 52 to determine the relative time delay between subchannels. For systems using more than two subchannels, the timing signal processor would process subchannel tuner outputs in pairs. Since the subchannels of FIG. 3 result from use of an uplink system 12 using power division, delay outputs IB and QB from delays 56 a , 56 b are correlated. This enables digital correlator 58 to compare digitized soft decisions between subchannels and provide additional information to receiver controller 42 about relative subchannel delay at the bit level. Digital power combiner 66 processes synchronized I and Q soft decisions from all subchannels to produce a single I and Q decision 68 for every set of soft decisions presented. For the case of QPSK modulation, each final decision from combiner 66 produces two bits in digital output 68 . Analog Division A third method for dividing and combining the original signal address the case that original signal 22 is analog in nature. Referring to FIG. 4 , receiver controller 42 directs multiple beam antenna 30 to point to selected transponder signals and directs tuners 32 a , 32 b to translate said transponder frequencies to a fixed band of frequencies expected by demodulators 70 a , 70 b . The exemplary system of FIG. 4 divides the signal into two subchannels, but the instant invention is not so limited. Demodulators 70 a, 70 b produce analog outputs signals which are faithful replicas of the subchannel signals produced by subchannel divider 24 in the uplink system 12 . Said analog signal outputs in general experience relative delay due to differing lengths of total propagation paths when using transponders on different satellites. Under direction of receiver controller 42 , analog delays 72 add delay to first-arriving subchannel signals so as to create outputs of analog delays 72 which arrive at analog combiner 80 with near zero relative delay. Analog delays 72 consist of a high quality analog-to-digital converter (A/D), a FIFO buffer, and a digital-to-analog (D/A) converter. Each of delays 72 creates a time delay in proportion the instant size of the FIFO buffer contained therein. Delays 72 present output signals to analog combiner 80 which represent faithful replicas of the subchannel signals produced by subchannel divider 24 in the uplink system 12 . These signals differ from outputs of demodulators 70 in that they are now time synchronized. FIG. 4 represents both signal division strategies, power division and content-division. In the first case of power-divided subchannel signals, inputs to analog combiner 80 represent identical signals, differing only in distortion and noise added by satellite transport. In a second case, time-synchronized content-divided subchannel signals arrive at analog combiner 80 . Analog combiner 80 creates output 82 most likely by a simple addition process, but is not so limited. In addition to producing combined output signal 82 , analog combiner 80 optionally provides a measure of time synchronization to receiver controller 42 to improve the accuracy of time alignment by controller 42 . As in first and second digital divider-combiner methods, timing signal correlator 44 provides relative subchannel delay information to receiver controller 42 , which together with further optional delay information from analog combiner 80 provides receiver controller 80 with a basis to create estimates of relative delay between subchannels; which in turn affects the setting of delays 72 . Mux Division A fourth method for dividing the original signal applies specifically to digital signals wherein the signal to be divided consists of a combination of a plurality of individual program streams as in a DVB Multiplex (MUX). As in the three previously described methods, subchannel divider 24 of FIG. 1 represents the signal dividing process. In this method, subchannel divider 24 splits the multiple signal into subsignals, placing information bits associated with any particular program stream entirely in the same subchannel. This requires a remultiplexing operation at the uplink facility but eliminates the need to recombine multiple substreams at the receiving terminal. The required receiver is shown in FIG. 5 which depicts a single tuner and demodulator but requires multiple beam antenna 30 , or multiple antennas, as the totality of signals in the service provided may necessarily pass through a plurality of satellites since the division process substantially increases the total satellite bandwidth requirement. The receiver block diagram is simplified since there is no requirement to recombine subchannels in this method. Internet Multibeam Antenna FIG. 6 provides more details of an exemplary multiple beam antenna 30 a for receiving Internet data. The multiple beam antenna 30 a is preferably a single ellipsoidal dish antenna with a major axis of approximately 24 to 30 inches. This allows simultaneous reception from up to five different satellites that are within a 30-degree arc. Exemplary signals that may be communicated include a 43 watt PAS 3R signal, a 45 watt PAS 1 signal, a 74 watt SBS 6 signal, an 81 watt SATCOM K2 signal, an 87 watt GE 3 signal, and a 123 watt SBS 5 signal. These signals are processed by a synchronization, timing, compression and decoding circuit block 90 . A personal computer 92 may then be the source and/or destination of the Internet data. The embodiment of FIG. 6 enables a reduced size and cost of the multiple beam antenna 30 a and the related processing circuitry 90 by reducing the size of the amplifier by approximately one-third, at the expense of increasing the bandwidth required by approximately three times. Assume the multiple beam antenna 30 a transmits to up to three satellites, and assume the three uplink signals are processed in such a manner as to make them identical after they have been transponded through the satellite transponders and received at a downlink antenna. At the downlink antenna, which may be located at an Internet gateway, the signals are reconstituted into a signal whose signal-to-noise ratio (SNR) is approximately 4.77 dB greater than any one of the received signals. Consequently, the EIRP of each of the channels transmitted from the multiple beam antenna 30 a (also referred to as a virtual antenna) can be 4.77 dB less than would be required should a single channel be employed to receive the same signal power at the gateway antenna. Specifically, assume N signals, which are exactly identical and perfectly synchronized, are to be perfectly combined. The N identical signals of amplitude X add to form a signal with amplitude N*X. The N uncorrelated, random signals with identical statistical properties and equal root-mean-squared (RMS) amplitude Y add to form a random signal with RMS amplitude equal to Y*sqrt(N). This process increases the SNR from X/Y to [N*X]/[Y*sqrt(N)], yielding an improvement of sqrt(N) in the amplitude domain. In the dB domain, the improvement is 20*log 10 (sqrt(N)) or 10*log 10 (N). For N=3, the improvement is 4.77 dB. Timing In first, second, and third divider-combiner methods, tuners 32 provide information to timing signal correlator 44 using one of two timing methods. In a first timing method, receiver controller 42 adjusts tuners 32 to receive timing signal 23 placed on all satellites with transponders used by the virtual satellite system. In this first method, tuner adjustment is necessary as the timing signals are placed at a frequency assignment separate form the information-bearing transponder signal. This out-of-band timing signal may be narrow-band in nature so as to conserve limited bandwidth on the satellite and reduce system cost. In general, timing signal 23 is unrelated to the information-bearing transponder signal in either information content, modulation strategy, or data rate or frame rate in the case of digital transmission, but the present invention is not so limited. The timing signal utilizes allocated bandwidth to enhance the resolution of relative subchannel delay estimation. Possibilities for the timing signals include pseudorandom noise, tone ranging, and time-dispersed pulse, but the instant invention is not so limited. A good timing signal must have a strong sharp cross-correlation with a time-shifted version of itself and have minimum spurious correlations. The instant invention includes two timing signal processor methods. In a first timing processor method, timing signal correlator 44 correlates output signals from tuners 32 at various relative delays until an acceptable correlation occurs indicating that the relative delay between the subchannels has been reproduced in timing correlator 44 . Receiver controller 42 then sets analog delays 72 in accord with this measured relative delay to synchronize inputs to analog combiner 80 . In the case that there are more than two subchannels in the virtual satellite channel, timing signal processor 44 compares subchannel signals pair-wise. In a second timing processor method, timing signal correlator 44 correlates the output from each tuner 32 with a stored version of the known timing signal, or by processing the recovered timing signal through a process that will produce a periodic output in response to the timing signal. One example of such a process is a matched filter, but the present invention is not so limited. Once the delays 40 , 56 , 72 are adjusted to remove relative subchannel delay, tuners 32 are set to conduct the selected information-bearing transponder signals to the respective demodulators in FIG. 1 , FIG. 2 , FIG. 3 . In a second timing method, the timing signal is as wide in bandwidth as the information-bearing transponder and resides in exactly the same bandwidth. In order to prevent distortion of the information signal, the timing signal is greatly attenuated. In order to recover the attenuated timing signal, timing signal correlator 44 first processes the tuner outputs through a linear system that creates a large processing gain to amplify the expected timing signal above the output created by the presence of the uncorrelated information-bearing carrier. The instant invention may use one of three exemplary processes to recover a low-level in-band timing signal, but the present invention is not so limited. In a first exemplary process the timing signal is a time-dispersed pulse with precise time dispersion introduced by a surface acoustic wave (SAW) filter in timing signal generator 23 . A matching SAW filter in receiving terminal 16 performs the inverse of the dispersion process, thus recovering the primary timing signal which is a periodic narrow-time pulse. In a second exemplary process, the timing signal is pseudorandom noise. Timing signal processor 44 then applies spread spectrum techniques to recover the timing of the low-level in-band timing signal. Upon timing signal acquisition, the correlated timing signal will experience a large process gain, but the uncorrelated information carrier will remain at the same relative level. This enables timing signal processor 44 to establish relative delay between subchannels, reporting results to receiver controller 42 . A third exemplary timing process uses a multiple tone signal to establish timing. The sine waves selected are harmonically related in such a way as to create a signal with a relatively long period, but giving good time resolution with the presence of some high frequencies. A linear filter at the selected frequencies recovers the timing signal in favor of the information carrier. Timing signal processor 44 then analyzes filtered timing signals to establish relative time delay between subchannels. In the case of the digital content-division receiver of FIG. 2 , there is typically no correlation between the subchannels to provide feedback as to the accuracy of the delay settings of delays 40 . This is a feed forward control system. Feedback is possible however in the exemplary systems of FIGS. 3 and 4 . Outputs from delays 56 in the digital power-division receiver of FIG. 3 are highly correlated. If the delay setting is slightly in error, a local digital correlation reveals the necessary small correction. Outputs from delays 72 in the analog receiver of FIG. 4 are correlated to some extent depending on the nature of the analog division and the instant properties of the analog content. This provides optional feedback to receiver controller 42 to affect local timing corrections. While several particular forms and variations thereof have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly it is not intended that the invention be limited, except by the appended claims.
A satellite communications system provides an information channel between remotely located transmitters and receivers. A virtual satellite system provides the same service, but divides the signal either in power or in data content into subchannels such that any particular signal is conducted to the intended receiver via a plurality of traditional satellite channels. The receiving terminal accepts the plurality of signals simultaneously from a possible plurality of satellites, combining the subchannels comprising the virtual channel into the original signal content as if conducted via a single channel. The receiving antenna system receives satellite subchannel signals from a plurality of directions using multiple antennas or a single antenna with multi-direction capability. Prior to signal combining, the receiver necessarily time-synchronizes the plurality of subchannels by introducing time delay in some channels before combining the subsignals into the original composite. A timing signal present in the virtual satellite system assists the receiver in determining the amount of delay to apply to each incoming signal. The timing signal is either a separate carrier or an additional modulation on the existing information-bearing carrier.
7
CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of U.S. patent application Ser. No. 09/690,301, filed Oct. 17, 2000 now U.S. Pat. No. 6,458,973. The present invention relates to a novel process for the preparation of 5-carboxyphthalide, a starting material for the manufacture of the well-known antidepressant drug citalopram, 1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile. BACKGROUND OF THE INVENTION Citalopram is a selective serotonin reuptake inhibitor which has successfully been marketed as an antidepressant drug for some years. It has the following structure: and it may be prepared by the process described in U.S. Pat. No. 4,650,884 according to which 5-cyanophthalide is subjected to two successive Grignard reactions, i.e. with 4-fluorophenyl magnesium halogenide and N,N-dimethylaminopropyl magnesium halogenide, respectively, and the resulting dicarbinol compound is subjected to a ring closure reaction by dehydration. The 5-cyanophthalide may in its turn be obtained by reaction of 5-carboxyphthalide with a dehydrating agent and a sulfonamide of the formula H 2 N—SO 2 —R wherein R is NH 2 , alkyloxy, optionally substituted phenyloxy, or substituted phenyl in order to obtain 5-cyanophthalide, cf. our co-pending Danish patent application No. PA199801718. 5-Carboxyphthalide has been described as a useful intermediate in the polymer and paint industry. However, no reliable commercial source is available at present. A known process comprises catalytic hydrogenation of trimellithic acid (DE-A1 2630927). This process provides a mixture of the 5- and 6-carboxyphthalides and, accordingly, it requires elaborate and costly purification. According to J. Org. Chem. 1970, 35, p. 1695-1696, 5-carboxyphthalide is synthesised by reaction of terephthialic acid with trioxanie in liquid SO 3 . During this process, trioxane sublimates and precipitates thereby obstructing the equipment. Though a number of other methods failed, it has now been found that 5-carboxyphthalide may be prepared from terephthalic acid in high yields by a convenient, cost-effective procedure. DESCRIPTION OF THE INVENTION Accordingly, the present invention provides a process for the manufacture of 5-carboxyphthalide comprising reaction of terephthalic acid with paraformaldehyde, HO(CH 2 O) n H, in oleum. By the process of the invention, 5-carboxyphtlialide is obtained with very high purity and in high yields (>about 75%). Furthermore, as compared with the prior art process (J. Org. Chem. 1970, 35, p. 1695-1696), the process of the invention takes place without precipitation of sublimated trioxane which obstructs the equipment e.g. by precipitating in condensers. The oleum used is commercially available oleum. So the following are available from Aldrich/Fluka: 12-17% SO 3 (Fuming sulfuric acid) 15% oleum 18-24% SO 3 (Fuming sulfuric acid) 20% oleum 27-33% SO 3 (Fuming sulfuric acid) 30% oleum From other sources 20% oleum contains 20-25% SO 3 In the method of the invention, the terephthalic acid is condensed with paraformaldehyde liberating water, which reacts with the SO 3 . When the reaction is complete, 5-carboxyphthalide may be isolated as follows. The reaction mixture is hydrolysed with water. The condensed product, 5-carboxyphthalide inclusive possible diphthalide impurities may then be filtered off, and the 5-carboxyphthalide may be dissolved in aqueous medium by adjusting pH to about 6.7 to 7.3, leaving possible diphthalide impurities in the solid phase The diphthalide present may be filtered off whereupon 5-carboxyphthalide may be precipitated by acidification, filtered off, washed with water and dried. Preferably 1.0-1.33 equivalents CH 2 O and 1.0-2.5, preferably 1.0-2.0 are used. More preferably 1.25-1.5 equivalents SO 3 per equivalent terephthalic acid are used. Most preferably, about 1.37 equivalents (corresponding to about 33 kg 20-25% oleum/kg terephthalic acid) are used per equivalent terephthalic acid. The reaction of terephthalic acid with paraformaldehyde is carried out at elevated temperature, conveniently at about 50-148° C., preferably 115-125° C. or 138-148° C. The reaction time is not critical and may easily be determined by a person skilled in the art, a reaction time of 17-21 hours is preferably used for a 210 kg batch at 115-125° C. The time is decreased with increasing temperature. The adjustment of pH to 6.3 to 7.3 in order to dissolve the 5-carboxyphthalide formed may be effected by NaOH, e.g. about 10% aqueous NaOH. Acidification in order to precipitate the 5-carboxyphthalide may be carried out by adding sulphuric acid until pH=2. The terephthalic acid used as a starting material is commercially available. EXAMPLES The invention is father illustrated by the following example. Example 1 5-Carboxyphthalid Terephthalic acid (10 kg) is charged into a reactor. Oleum (20% (18-24% SO 3 ); 6 kg/kg terephthalic acid ) is added and then paraformaldehyde (1.33 equivalents, 0.24 kg/kg terephthalic acid) is added. The mixture is agitated at 125° C. for 17 hours. Water (13 kg/kg terephthalic acid and filter aid is added, the temperature is adjusted to about 70° C. The precipitate is filtered of, washed with water and suspended in water. The pH of the suspension is adjusted to about 7 with NaOH, activated carbon, 0.07 kg/kg terephthalic acid is added, and then the mixture is filtered, the precipitate is rinsed with water. The temperature of the filtrate is adjusted to about 65° C. and the pH is adjusted to about 2 with 50% sulfuric acid. The 5-carboxyphthalide precipitated is separated by filtration washed and dried. Yield 83%. Example 2 5-Carboxyphthalid Oleum (20-25% SO 3 43 kg) is charged into a reactor. Terephthalic acid (13 Kg) and then paraformaldehyde (3.8 Kg) is added. The mixture is agitated at 138-148° C. for 4½ hours. Water (87 L) is added and the temperature is adjusted to about 100° C. The precipitate is filtered of, washed with water and suspended in water. The pH of the suspension is adjusted to about 7 with NaOH (about 10%), activated carbon, 0.5 Kg is added, and then the mixture is filtered, the precipitate is rinsed with water. The temperature of the filtrate is adjusted to about 85° C. and the pH is adjusted to about 2 with 96% sulfuric acid. The 5-carboxyphthalide precipitated is separated by filtration washed and dried. Yield 82%.
5-carboxyphthalide is obtained with very high purity and in high yields by a convenient process comprising reaction of terephthalic acid with paraformaldehyde HO(CH 2 ) n H in oleum.
2
FIELD OF THE INVENTION [0001] The present invention generally pertains to computer systems, and more particularly to a computer system wherein a central processing unit, a plurality of media drivers, various electrical and power cables and other hardware components are all housed within structure used to support a plurality of viewing screens. BACKGROUND OF THE INVENTION [0002] With present day computer systems, the configuration of the system is often limited and does not provide for much flexibility in terms of being able to mix and match peripherals. This is especially so for the display portion of the system. With systems employing a liquid crystal display (LCD) screen, there is often no means for easily attaching additional LCD screens, or for reconfiguring two or more existing screens, or for allowing easy and quick removal and/or replacement of one of more LCD screens of different sizes. [0003] Another disadvantage with present day computer systems is the large number of electrical cables that must be used to couple the CPU with the peripherals. This is especially so when two or more LCD screens are used. Each LCD screen requires its own data cable and power cable, so, for example, a three LCD screen system would require, for example, six cables to be coupled to the LCD screens. As will be appreciated, these cables significantly clutter the user's work area. When power and data cables from additional peripherals such as DVDs, ZIP drives, etc, are added, the collection of cables can significantly interfere with the work space of the user. [0004] In view of these drawbacks, it would be highly desirable to provide a modular computer system which allows one or more LCD screens to be used, according to the user's needs, and which permits easy adding or removal of LCD screens without significant and time consuming disassembly steps being required. [0005] Just as importantly, it would be desirable to provide a computer system which includes a support structure capable of housing the power and data cables needed for coupling the LCD screens and peripherals making up the system to the CPU. In this manner, the large number of data and power cables could be maintained out of the user's sight and out of the user's immediate work area. SUMMARY OF THE INVENTION [0006] In one preferred form the present invention provides a display screen support system which functions to support one or more video display screens, as well as to house a computer system and related electrical and power cabling. In one preferred form the display screens comprise liquid crystal display (LCD) screens. The screen support system includes a support, which in one preferred form comprise a base, having a central processing unit interface portion for selectively interconnecting with a central processing unit housed within the base. A column extends upwardly from the base. A laterally extending arm includes an engagement portion for selectively coupling to a complimentary engagement portion disposed in the column. At least one bracket is coupled to the arm and is operable to slidably traverse the arm. The bracket is configured to couple with an associated LCD screen. [0007] The present invention thus makes use of the structure that would ordinarily just be used to support the LCD screen(s) to also house the central processing unit (CPU), one or more power supplies, and various cables typically used to couple the LCD screen(s) with the CPU and also to provide power to the LCSs and other electronic components of the system. In this manner the numerous cables and power supplies that would typically be present on and around a user's work area are all hidden within the LCD support system. This makes for a very organized and aesthetically appealing support structure. BRIEF DESCRIPTION OF THE DRAWINGS [0008] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: [0009] [0009]FIG. 1 is a rear perspective view of the computer system according to a first embodiment shown with the dual arm in the installed portion; [0010] [0010]FIG. 2 is a rear perspective view of the computer system according to a first embodiment shown with the dual arm and cover detached from the computer system as well as engaged working peripherals; [0011] [0011]FIG. 3 is a view of the computer system of FIG. 1 shown with the cover removed for illustration; [0012] [0012]FIG. 4 is a front perspective view of the computer system of FIG. 1; [0013] [0013]FIG. 5 is a rear perspective view of the computer system of FIG. 1 shown with a central processing unit in an installed position; [0014] [0014]FIG. 6 is a rear perspective view of a central processing unit and a standalone base shown in an uninstalled position; [0015] [0015]FIG. 7 is a perspective view of the central processing unit installed to the standalone base shown with the door partially opened; [0016] [0016]FIG. 8 is a rear perspective view of the computer system according to a second embodiment; [0017] [0017]FIG. 9 is a rear perspective view of the computer system of FIG. 8 shown with the vertical arm and slider brackets in an uninstalled position; [0018] [0018]FIG. 10 is a front perspective view of the computer system of FIG. 8; [0019] [0019]FIG. 11 is a rear perspective view of the computer system according to a third embodiment; [0020] [0020]FIG. 12 is a rear perspective view of the computer system according to a fourth embodiment; [0021] [0021]FIG. 13 is a rear perspective view of the computer system according to a fifth embodiment; [0022] [0022]FIG. 14 is a rear perspective view of the computer system according to a sixth embodiment; [0023] [0023]FIG. 15 is a detailed view of a slider bracket and track incorporated on the dual arm; [0024] [0024]FIG. 16 is a rear perspective view of the computer system according to a seventh embodiment; [0025] [0025]FIG. 17 is a rear perspective view of the computer system of FIG. 16 having the elevator mechanism upwardly extending from a central portion of the base; [0026] [0026]FIG. 18 is rear perspective view of the computer system according to an eighth embodiment; and [0027] [0027]FIG. 19 is a rear perspective view of the computer system according to a ninth embodiment. [0028] [0028]FIG. 20 is a rear perspective view of the computer system according to a tenth embodiment. [0029] [0029]FIG. 21 is a rear perspective view of the computer system according to an eleventh embodiment. [0030] [0030]FIG. 22 is a rear perspective view of the computer system according to a twelfth embodiment having a selectively removable CPU module. [0031] [0031]FIG. 23 is a rear perspective view of the computer system according to a thirteenth embodiment having a primary and secondary docking cradle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0032] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. [0033] With initial reference to FIGS. 1 through 4, a support system 10 in accordance with a preferred embodiment of the present invention is shown. In one preferred form the support system 10 forms an LCD support system, and will be referred throughout herein as such. The LCD support system 10 includes a support forming a base 12 having a central processing unit (CPU) interface portion 14 and a generally upright column 20 extending therefrom. [0034] A central portion 22 of the upright column 20 includes a mounting post 24 for slidably accepting a mounting bracket 30 (FIG. 2) extending from a dual arm LCD support 32 . The dual arm 32 extends generally parallel to base 12 and perpendicular to column 20 in a mounted position (FIG. 1). Slider brackets 28 (FIGS. 3 and 4), as will be described later in greater detail, include a first portion coupled for slidable engagement with dual arm 32 and a second portion configured for engaging a pivot bracket 38 coupled to an LCD viewing screen. A cover 40 (FIG. 3) includes ears 42 extending from opposite ends thereof for engaging complimentary slots (not specifically shown) incorporated along opposite sides of the central portion 22 . The cover 40 encloses the mounting post 24 and bracket 30 connection and creates a more uniform surface across the upper portion of column 20 . [0035] With continued reference to FIGS. 1 through 4, base 12 will now be described in greater detail. It will be appreciated that the base 12 could take a variety of shapes and/or configurations. Accordingly, the illustration of the base 12 as a laterally extending component is merely for exemplary purposes. Base 12 includes a generally longitudinal central portion 50 having selectively removable foot portions 44 transversely extending on opposite ends thereof. The foot portions 44 may comprise non operative structural members (FIG. 1) or alternatively comprise working peripherals 46 , 48 (FIG. 2) such as a digital video disk (DVD) or a compact disk readable writable (CDRW) module for example. In addition, one or both of the foot portions may include an alternative data storage drive such as a secondary hard drive or ZIP drive. The foot portions 44 , 46 and 48 include pins and receivers configured on inboard surfaces thereof (not specifically shown) for mating with complimentary pins and receivers configured on outboard edge surfaces (not specifically shown) of central portion 50 for easy “plug and play” capability. CPU interface portion 14 is centrally configured along central portion 50 and, as with foot portions 46 , 48 , includes pins and receivers for complimentarily mating with pins and receivers disposed on CPU 100 (FIG. 7) for easy “plug and play” capability. In this regard, CPU 100 (FIG. 4) may be easily detached from LCD support system 10 and relocated to a second computer system. As such, the portability allows the user to move from a first computer system configuration to an alternative computer system configuration which may employ different amounts of viewing screens having alternate orientations as will be discussed in the alternate embodiments herein. Also importantly, the inclusion of the CPU interface portion 14 in the base 12 eliminates the need for electrical cabling to be used exteriorly of the system 10 , which would clutter the user's work area. Likewise the attachment of working peripherals 46 , 48 eliminates the need for external electrical cabling to connect with the CPU interface 14 . This further helps to provide a very uncluttered work area around the LCD support system 10 . In one preferred form the base 12 also houses the power supplies needed for powering one or more LCD screens. [0036] As shown in FIGS. 1, 2 and 4 , LCD support system 10 includes two slider brackets 38 arranged on opposite ends of dual arm 32 . FIG. 3 is shown having a third slider bracket 38 centrally located along extended dual arm 26 . Dual arm 26 has a horizontal span sufficient to accommodate three adjacent LCD screens. [0037] Referencing now FIG. 5 the LCD support system 10 according to the first embodiment is shown with CPU 100 in an installed or docked position. CPU 100 includes vertically oriented connection ports 94 for suitably interfacing with an external pointing device, keyboard and the like. FIG. 6 illustrates an alternative configuration wherein a standalone base unit 112 is provided. The standalone base unit 112 may be used when viewing multiple screens is not required. While not specifically shown, a dual connection port arrangement may also be employed in a side-by-side relationship such that two CPU units 100 may be concurrently docked. Such a setup would provide further memory or processing capability when additional computing resources are desired. In each scenario, the pins and receivers incorporated on the CPU interface portion 14 are configured to mate with complimentary pins and receivers (not specifically shown) disposed on a bottom face of the CPU. As shown in FIG. 7, CPU 100 includes a hingedly attached door 102 for easy access to hard drive 104 . [0038] Turning now to FIGS. 8 - 10 , the present invention will be described according to a second embodiment wherein like reference numbers increased by 100 will be used to designate components corresponding to system 10 . In this regard, LCD support system 120 includes base 112 shown in cooperative engagement with vertical arm 160 . A pair of grooves (not specifically shown) are arranged along opposing inner walls 162 of column 120 to interface with a pair of tongues 164 extending along opposite sides of the arm 160 . First and second slider brackets 128 are coupled for slidable engagement with vertical arm 160 . First and second pivot brackets 138 selectively couple to first and second slider brackets 128 to provide pivotal movement for a mounted LCD viewing screen. Such a configuration provides for first and second LCD screens to be adjacently mounted in a vertical orientation. [0039] Turning now to FIG. 11, the present invention will be described according to a third embodiment wherein like reference numbers increased by 200 over those used in connection with system 10 will be used to designate like components. As shown, LCD support system 200 includes a vertical arm 260 mounted to the central portion 222 of upright column 220 as previously described. In addition, a slider bracket (not specifically shown) operably interconnects dual LCD support arm 232 to a lower portion of vertical arm 260 . This arrangement provides a pyramid configuration in which three LCD screens may be selectively mounted to pivot brackets 238 in a triangular relationship. [0040] Referring now to FIG. 12, LCD support structure 300 will be described according to a fourth embodiment. Like reference numbers increased by a factor of 300 over those used in connection with system 10 will be used to designate like components. Again, both the dual arm 332 and the vertical arm 360 are mounted to column 320 . In addition, a second dual arm 332 is slidably mounted on vertical arm 360 with mounting bracket 330 . [0041] [0041]FIGS. 13 and 14 illustrate the invention according to fifth and sixth embodiments, respectively. As such, the LCD support system 400 of the fifth embodiment includes a vertical arm 460 having a dual arm 432 extending from an upper portion thereof. This configuration allows two LCD screens to be adjacently mounted in a side by side relationship as well as a third LCD screen mounted on a lower portion of the vertical arm 460 . While not specifically shown, the LCD screens are preferably mounted to pivot brackets which in turn attach to the slider brackets for slidable movement along dual arm 432 . [0042] Referring to FIG. 14, LCD support system 500 of the sixth embodiment, similar to the fifth embodiment, includes a vertical arm 560 having a dual LCD support arm 532 extending from an upper portion. The lower portion of the vertical arm 560 , however, includes a horizontal arm 566 mounted thereat. The horizontal arm 566 includes three mounting portions for coupling slider and pivot bracket combinations. This configuration provides two viewing screens adjacently mounted side-by-side on the dual arm 532 as well as three viewing screens adjacently mounted to each other and arranged along horizontal arm 566 under the dual arm 532 . [0043] Referencing now FIGS. 8 and 15, the slider bracket 28 and pivot bracket 38 will be described in greater detail. Pivot bracket 38 , will be described with reference to pivot bracket 138 of the second embodiment in FIG. 8. Likewise, while the description of pivot bracket 138 is described in relation to the second embodiment it is appreciated that the description applies to all pivot brackets referred to herein. In addition, while slider bracket 28 is shown operatively associated with dual arm 32 in FIG. 15, it will be apparent that the same slider bracket 28 configuration is employed for vertical arm 60 (FIGS. 8 and 9). [0044] Slider bracket 28 generally comprises a C-shaped member defined by outwardly extending fingers 70 . A front face portion 72 includes a recessed rectangular portion 74 for receiving a foot 176 of the pivot bracket 138 . The geometry of slider bracket 28 allows for slidable communication along track 80 . In this regard, oppositely extending rails 82 are formed along dual arm 32 for settling into arcuate portions 78 of slider bracket 28 . A quick connector or similar fastening member (not shown) extends through channel 84 for engaging bore 186 formed in foot 176 . Pivot bracket 138 generally comprises a ball 188 received in a socket 190 for pivotal rotation thereabout. Post 192 connects foot 176 to ball 188 . A front face 152 (FIG. 10) of pivot bracket 138 includes a groove channel 154 for receiving a mounting portion (not shown) of a viewing screen (not shown). The rail and track configuration explained herein with respect to dual arm 32 is similarly employed for mounting post 24 extending from central portion 22 of column 20 . It will be appreciated by those skilled in the art that slider bracket 28 and pivot bracket 138 are merely exemplary and other brackets having different geometries may be similarly employed while reaching similar results. [0045] Turning now to FIGS. 16 and 17 an LCD support system 600 is provided according to a seventh embodiment wherein like reference numbers increased by 600 over these used in conjunction with system 10 will be used to designate like components. In this regard, an alternative base portion 612 and column 620 are shown having a CPU interface panel 614 operatively disposed on a vertical rear face 634 . A CPU unit having vertically oriented pins and receivers (not shown) would be used to mate with interface panel 614 . FIG. 17 also shows the computer system having an integrated elevator mechanism 654 . The elevator mechanism 654 provides a vertical mechanical assist for adjusting the vertical orientation of a dual or vertical arm such as those discussed herein. Elevator 654 generally includes a static tower having a movable bracket 656 . Bracket 656 is actuated by a rack and pinion configuration or other suitable mechanism. LCD support system 600 is also shown with foot portions 644 having an alternate geometry. It will be understood that foot portions 644 include pins and fasteners which mate with complimentary pins and fasteners disposed on base 612 . In this regard, foot portions 644 may comprise non-operative structural members or working peripherals as previously described. Although elevator mechanism 654 is shown operatively associated with the seventh embodiment, it will be understood that elevator mechanism 654 may similarly be employed with the other embodiments disclosed herein. [0046] Referencing FIG. 18 an LCD support system 700 according to an eighth embodiment is shown wherein like reference numbers increased by 700 over those used in conjunction with system 10 will be used to designate like components. Support system 700 includes integral base 712 and column 714 . As such, column 714 houses the main motherboard, CPU, hard drive and floppy drive. A sound card is also preferably integrated on the motherboard. Base 712 houses the main power supply and peripheral devices 744 which may include DVD, CD-ROM or ZIP drives for example. Peripherals 744 are built into base 712 . [0047] Arm 726 is laterally mounted using the aforementioned slider bracket configuration. Arm 726 accepts multiple displays 702 by way of pivot brackets 738 . The necessary wiring to run power and signals from the graphics card to the displays 702 is channeled through arm 726 . Speakers 704 are coupled at opposite ends of arm 726 . Likewise, the necessary wiring for speakers 704 is routed through arm 726 . [0048] Column 714 , which operably houses the motherboard and CPU, includes vent ports 734 integrated thereon. Connection panel 794 includes parallel and serial ports, USB, NIC, audio interface ports, AC and PS2 connectors. A multi-output graphics adapter is preferably integrated on the motherboard (within column 714 ) or may also be mounted as a separate card within arm 726 . A power supply vent 756 is incorporated on base 712 . [0049] [0049]FIG. 19 illustrates an LCD support system 800 according to a ninth embodiment wherein like components in common with system 700 are designated by reference numbers increased by 100 over those used in connection with system 700 . As with eighth embodiment 700 , the base 812 and column 814 are an integral unit. LCD support structure 800 includes arm 826 having an arched contour. All necessary wiring for displays 802 is channeled through arm 826 . Column 814 is tapered toward an upper edge and extends a sufficient amount to accommodate the vertical displacement of arm 826 . [0050] [0050]FIG. 20 illustrates an LCD support system 900 according to a ninth embodiment wherein like components in common with system 800 are designated by reference numbers increased by 100 over those used in connection with system 800 . Support system 900 includes integral base 912 and column 914 . Three displays are horizontally arranged across arm 926 . Display 906 incorporating transmitter 964 is arranged together with two displays 902 . Transmitter 964 is integrated with CPU module 966 and provides wireless networking capability to system 900 . Interface panel 968 includes parallel and serial ports, USB, NIC, audio, AC and PS2 connections. Arm 926 includes an internal passage for housing all necessary cables and wires. [0051] [0051]FIG. 21 illustrates an LCD support system 1000 according to a tenth embodiment wherein like components in common with system 900 are designated by reference numbers increased by 100 over those used in connection with system 900 . Three LCD displays are arranged in a triangular relationship. Display 1006 has a transmitter 1064 coupled to column 1014 by way of pivot bracket 1038 and is disposed above adjacent displays 1002 . [0052] Turning now to FIG. 22 an LCD support system 1100 including removable CPU 1166 is shown. Like components in common with system 1000 are designated by reference numbers increased by 100 over those used in connection with system 1000 . Display 1108 includes cradle 1110 for selectively receiving CPU 1166 . In this way, CPU 1166 may be transferred from one support system to another. It should be noted that the central placement of display 1108 is merely exemplary and display 1108 may alternatively be placed on either end of arm 1126 . In addition, it will be appreciated that display 1108 incorporating removable CPU 1166 may be used in conjunction with any support system described herein. [0053] [0053]FIG. 23 shows LCD support system 1200 . Like components in common with system 1100 are designated by reference numbers increased by 100 over those used in connection with system 1100 . Support system 1200 includes a multiport docking system 1296 . Docking system 1296 includes a cradle 1210 integrated with display 1208 as well as a secondary cradle 1258 . Secondary cradle 1258 is coupled to base 1212 . Interface panel 1268 includes parallel and serial ports, USB, NIC, audio interface ports, AC and PS2 connectors. [0054] It will be appreciated that all of the preferred embodiments described herein completely eliminate or substantially reduce the need for any external electrical cabling for coupling various subcomponents making up the various LCD support systems, as well as the need for external power supplies. The preferred embodiments thus all serve to provide a very uncluttered LCD support system which has built in to it all the connectors necessary to effect coupling of the various subcomponents to one another. Also, while reference has been made throughout to LCD screens, it will be appreciated that the support system disclosed herein is equally well suited to be used with virtually any type of flat panel-type display screen, or other form of display screen. [0055] While the invention has been described in the specification and illustrated in the drawings with reference to various preferred embodiments, 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 as defined in the claims. For example, the integral base and column may be incorporated with any of the computer systems disclosed herein. Therefore, it is intended that the invention not be limited to the particular embodiments illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the invention, but that the invention will include any embodiments falling within the present description and the appended claims.
An LCD support system includes structure adaptable to selectively accommodate a central processing unit, a plurality of media drivers and a plurality of viewing screens so that no external electrical cabling is needed to couple the various subcomponents to one another. The plurality of viewing screens are selectively positioned along vertical and/or horizontal arms extending from the structure. Slidable brackets having viewing screens coupled thereto are movable along the arms of the structure to customize the multiple viewing screen arrangement according to a desired spacing and/or setup. A central processing unit may be readily detached from a first computer system having a first viewing screen configuration and attached to a second computer system having an alternative viewing screen configuration. The present invention provides a very compact, uncluttered means for supporting one or more LCD screens.
8
This application claims the benefit of U.S. Provisional Application No. 60/789,673, filed Apr. 5, 2006, and entitled Retrofitting of Fluorescent Tubes with Light-Emitting Diode (LED) Modules for Various Signs and Lighting Applications. FIELD OF THE INVENTION The present invention relates to the design and the installation of retrofit Light Emitting Diode (LED) modules to replace existing fluorescent tube lamps typically found in street lights, parking lot lights, and various other lighting applications. More particularly, the present invention relates to a method and apparatus for installing a retrofit LED module in a conventional fluorescent tube lamp housing. BACKGROUND OF THE INVENTION Light emitting diodes (LEDs) have been widely used in many applications to replace conventional incandescent lamps, fluorescent lamps, neon tube lamps and fiber optic lights. LEDs consume much less electrical power, are far more reliable, and exhibit much longer lifetimes, than their conventional counterparts. As a result, LEDs have been configured to replace conventional light sources for many applications. For example, LED lamps have been. developed to replace screw-in incandescent light bulbs for traffic signals (as shown in U.S. Pat. No. 6,036,336), and exit signs (as shown in U.S. Pat. Nos. 5,416,679, 5,459,955, 5,526,236, 5,688,042, 5,949,347). In each case, the LEDs are mounted onto a lamp housing having a conventional threaded electrical connector that engages with the threaded socket connector in the traffic signal lamp or exit sign. Thus, retrofitting the traffic signal and exit signs simply involves unscrewing the conventional lamp and screwing in the LED lamp. Retrofitting with LED lamps the vast numbers of backlit commercial and street name signs, which utilize fluorescent lighting, is more problematic. These signs typically include a housing containing one or more fluorescent tube lamps, and one or more translucent face plates (sidewalls) that are back-illuminated by the fluorescent lamp(s) (i.e. to form characters, designs, symbols, etc.). FIGS. 1A and 1B illustrate a conventional backlit street name sign, which includes a housing 1 , a pair of fluorescent tube lamps 2 and a pair of opposing translucent face plates 3 that indicate a street name. Each of the fluorescent tube lamps 2 are connected to and suspended by a pair of electrical connectors 4 , which are well known in the art. Connectors 4 have receptacles that accept and make electrical connections with a pair of standard electrical pins protruding from each end of the fluorescent tube lamp 2 . Connectors 4 physically support the fluorescent tube lamp by the pins, as well as apply an operating voltage across them. The face plates 3 are angled slightly downwardly for better viewing from below. FIGS. 2A and 2B illustrate a conventional backlit commercial sign, where there is only a single translucent face plate 3 (which is not angled downwardly), and three fluorescent tube lamps 2 for illumination. Replacing the short-lifespan fluorescent tube lamps in conventional backlit commercial and street name signs can be difficult, because such signs are typically elevated and inaccessible, disposed over roadways, and/or hard to open. What is worse is that there is no standard size for such signs, for the fluorescent tube lamps 2 used therein, and for the spacing between opposing electrical connectors 4 . Thus, designing an LED lamp retrofit that fits a wide variety of such signs, that evenly and sufficiently illuminates such signs, and that is easy to install without the need for special tools, has been difficult. Adding to that difficulty is the fact that many such signs are suspended in a way where the sign rocks, vibrates and shakes in the wind. There is a need for a versatile LED lamp design for retrofitting conventional backlit commercial and street name signs that is easy to install and fits in a variety of sign sizes and configurations. SUMMARY OF THE INVENTION The present invention solves the aforementioned problems by providing a method and apparatus for installing a retrofit LED lamp module in a housing designed for fluorescent tube lamps. An LED lamp, for use in a housing designed for fluorescent tube lights, includes an elongated electrical assembly having a first end terminating in a first electrical connector and a second end terminating in a second electrical connector, a plurality of LEDs mounted to the elongated electrical assembly, a first mounting adaptor having a first end electrically engagable with the first electrical connector and a second end terminating in an electrical connector having two protruding pins, and a second mounting adaptor having a first end electrically engagable with the second electrical connector and a second end terminating in an electrical connector having two protruding pins. A method for retrofitting a fluorescent lamp (containing a fluorescent tube lamp connected between first and second socket connectors) includes removing the fluorescent tube lamp from the first and second socket connectors, and connecting an LED lamp to the first and second socket connectors. The LED lamp includes an elongated electrical assembly having a first end terminating in a first electrical connector and a second end terminating in a second electrical connector, a plurality of LEDs mounted to the elongated electrical assembly, a first mounting adaptor having a first end electrically engagable with the first electrical connector and a second end terminating in an electrical connector having two protruding pins, and a second mounting adaptor having a first end electrically engagable with the second electrical connector and a second end terminating in an electrical connector having two protruding pins. The connecting of the LED lamp to the first and second socket connectors includes connecting the two protruding pins of the first mounting adaptor to the first socket connector and connecting the two protruding pins of the second mounting adaptor to the second socket connector. Other objects and features of the present invention will become apparent by a review of the specification, claims and appended figures. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a partially broken away side view of a conventional backlit street name sign. FIG. 1B is a cross-section view of the conventional backlit street name in FIG. 1A . FIG. 2A is a partially broken away side view of a conventional backlit commercial sign. FIG. 2B is a side cross-section view of the conventional backlit commercial sign in FIG. 2A . FIG. 3 is a schematic of an LED module according to an embodiment of the present invention. FIG. 4A is schematic of a mounting adaptor with extension wires within the coil and spacer of the mounting adaptor. FIG. 4B is schematic of a mounting adaptor with extension wires outside the coil and spacer of the mounting adaptor. FIG. 5A is a cross section view of an LED tube, wherein LEDs are mounted on only one side of an electrical assembly. FIG. 5B is a cross section view of an LED tube, wherein LEDs are mounted on each of two surfaces of an electrical assembly. FIG. 5C is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a triangular configuration. FIG. 5D is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a square configuration. FIG. 5E is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a trapezoidal configuration. FIG. 5F is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a hexagon configuration. FIG. 5G is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having two surfaces, and wherein the LEDs are partially angled towards each other. FIG. 5H is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a circular configuration. FIG. 5I is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having three surfaces, and wherein the LEDs are partially angled towards each other. FIG. 5J is a cross section view of an LED tube, wherein LEDs are mounted onto an electrical assembly having a semi-circle configuration. FIG. 6A is a front-view schematic of a vertical mounting support for the LED module of the present invention. FIG. 6B is a side-view schematic of a vertical mounting support for the LED module of the present invention. FIG. 7 is a side view of the mounting mechanism for the LED module of the present invention. FIG. 8A is front-view schematic of an installed LED module according to an embodiment of the present invention. FIG. 8B is side-view schematic of an installed LED module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to the design and the installation of retrofit LED modules to replace existing fluorescent tube lamps. Moreover, the present invention provides a method and apparatus for installing a retrofit LED lamp module in a housing designed for fluorescent tube lamps. In FIG. 3 , a schematic of an LED module 100 according to an embodiment of the present invention is provided. As illustrated, LED module 100 includes a plurality of LEDs 111 mounted onto an elongated electrical assembly 110 (e.g. a printed circuit board, a plurality of electrical receptacles, etc.), and preferably housed within a translucent LED tube 112 . On both ends, LED module 100 includes bi-pin connectors 114 , which allow LED module 100 to electrically connect to mounting adaptors 120 via bi-pin holes 122 . In a preferred embodiment, each mounting adaptor 120 further comprises bi-pin connectors 124 , which allow each adaptor 120 to electrically connect to a conventional fluorescent tube socket 200 . Conventional fluorescent tube sockets are well known, and include holes or channels for receiving and making electrical contact with bi-pin connectors. Mounting adaptor 120 is designed to facilitate the installation of the LED retrofit tube onto existing fluorescent tube lighting fixtures. In FIGS. 4A and 4B , schematics of a mounting adaptor 120 according to embodiments of the present invention are provided. As illustrated, mounting adaptor 120 includes a housing 129 , a rotatable bi-pin socket 123 , extension wires 121 , tube spacer 126 , coil 128 , and bi-pin connector 124 . Optional rotation threads 125 can be included on the rotatable pin socket 123 and mounting adaptor housing 129 for adjusting the angular position of rotatable pin socket 123 relative to bi-pin connector 124 . It should be further appreciated that the placement of extension wires 121 may also vary. For example, in the embodiment of FIG. 4A , extension wires 121 are located within the coil 128 and spacer 126 of mounting adaptor 120 . In FIG. 4B , however, an alternative embodiment is provided, wherein extension wires 121 are located outside the coil 128 and spacer 126 . In a preferred embodiment, the insertion of mounting adaptor 120 into an existing fluorescent tube socket 200 allows for the orientation of LED module 100 to be easily adjusted within a conventional fluorescent tube lamp housing 1 via rotatable bi-pin socket 123 . Namely, bi-pin connectors 124 will serve the equivalent function of bi-pin connectors on conventional fluorescent tube lamps, while coils 128 provide the necessary force between LED module 100 and mounting adaptor 120 so as to facilitate installation. Moreover, after installation of LED module 100 is complete, and wherein the desired orientation is set, pressure from each compressed coil 128 provides the necessary frictional force to firmly hold LED module 100 in place and to keep the orientation of the LED module 100 fixed. Optional rotation threads 125 can lack any inclination, whereby rotating pin socket 123 simply causes it to spin in place. Alternately, the rotation threads 125 can be inclined, whereby rotation of the pin socket 123 adjusts the distance between the rotatable pin socket 123 and bi-pin connector 124 to custom fit the LED lamp to the lamp fixture. To retrofit a conventional sign, its housing if any is opened and the fluorescent tube lamp(s) therein are removed from sockets 200 . A mounting adaptor 120 is inserted into each of the sockets 200 (i.e. pins 124 are inserted into socket 200 ), and LED module 100 is inserted into the mounting adaptors 120 (i.e. pins 114 are inserted into pin holes 122 ). It should be understood that the LED module 100 could be connected to the mounting adaptors 120 before or after the mounting adaptors 120 are connected to the sockets 200 . Then, the LED module 100 is rotated to its desired rotational position (which possibly could be used to adjust the overall length of LED module 100 and mounting adaptors 120 between sockets 200 ), where the compressed coils 128 maintain this rotational position thereafter. The electrical connection is automatically made to supply the operating voltage to from the sockets 200 , through the mounting adaptors 120 , and to the LED module 100 . The LED module preferably includes an internal power supply 116 that transforms the operating voltage from the sockets 200 to an operating voltage appropriate to the LEDs 111 . Alternately, wires 118 extending from the internal power supply 116 could be used power the LED module 100 independent from the sockets 200 (as shown in FIG. 3 ), whereby sockets 200 and mounting adaptors 120 simply provide mechanical support to the pins 114 of LED module 100 . It is also possible to make power supply 116 external to the LED module 100 . It should also be appreciated that LEDs 111 may be mounted onto electrical assembly 110 in a variety of ways. Several examples of such configurations are provided in FIGS. 5A-5J . As illustrated, some of these configurations include configurations in which electrical assembly 110 comprises a single surface, a plurality of surfaces, a curved surface, and/or surfaces configured in particular shapes. Depending on the length and the weight of the particular LED module 100 used, a special mechanical support structure might be necessary. Some street name signs, for example, because of their size, require mechanical support for there to be an adequate retrofit. In FIGS. 6A and 6B , exemplary schematics of such supports are provided. As illustrated, vertical support 300 comprises a top mount 310 , a bottom mount 320 , and an adjustable tube holder 360 . In a preferred embodiment, adjustable tube holder 360 is used to support and secure LED module 100 , wherein tube holder 360 is secured with position locking nuts 350 by inserting threads 340 into holes 330 , as shown. In applications requiring mechanical support a mounting mechanism 400 may be utilized as illustrated in FIG. 7 . The mounting mechanism 400 includes a mounting member 430 either rigidly connected to or integrally formed as part of one of the support arms 500 , a pair of scissor arms 410 , a pair of adjustment screws 412 , and a tightening screw 414 . The scissor arms 410 are preferably S-shaped, and each includes an upper portion 410 a , a mid-portion 410 b , a lower mid portion 410 c , and a lower portion 410 d . The scissor arm mid portions 410 b are rotatably connected together by a bolt 416 that extends through a vertical slot 418 formed in the mounting member 430 . For each scissor arm 410 , a bolt 420 extends from its lower mid-portion 410 c and through a horizontal slot 422 formed in the mounting member 430 . Each of the adjustment screws 412 is threaded through the lower portion 410 d of one of the scissor arms 410 , and terminates in an engagement surface 413 . In the preferred embodiment, each adjustment screw 412 includes an engagement block of material 424 conducive to forming a friction fit (e.g. compressible or course materials, etc), with the engagement surface 413 at the end of the engagement block 424 . The tightening screw 414 is threaded through one of the scissor arm upper portions 410 a , and is rotatably engaged with the other scissor arm upper portion 410 a . Each of the screws 412 / 414 includes a conventional adjustment end (Phillips, flat blade, Allen key, etc.) for rotation thereof, thus allowing the LED module 100 to be installed with no special tools (i.e. nothing more than just a screw driver or Allen key). To retrofit a conventional backlit sign mounting mechanism 400 , its housing is opened and the fluorescent tube lamps therein are removed. The adjustment screws 412 of the LED module(s) to be inserted inside the sign are adjusted so that the engagement surfaces 413 for each pair of adjustment screws 412 are separated slightly less than the interior depth of the sign's housing at its base. After the LED module is placed inside the sign housing, each of the mounting mechanisms are operated by rotating its tightening screw 414 to separate the scissor arm upper portions 410 a from each other, which also separates the lower portions 410 d from each other as well, thus driving the engagement surfaces 413 away from each other and against the sign's sidewalls to form a secure friction fit there between. As the tightening screw 414 is adjusted, the bolts 416 / 420 slide in slots 418 / 422 to accommodate the movement of the scissor arms 410 , while minimizing the vertical movement of the mounting member 430 during installation. Bolts 416 / 420 secure the scissor arms to the mounting member 430 , to ensure support arm 500 (which is used to support the LED module 100 ) cannot move relative to the sign's housing once installation is complete. The minimum sign depth compatible with the mounting mechanism is dictated mainly by the sizes of the mounting member 430 and scissor arms 410 , and the maximum sign depth compatible with the mounting mechanism 400 is dictated mainly by the length of the adjustment screws 412 (i.e. how far the engagement surfaces 413 can be separated). Thus, a single sized mounting mechanism 400 can be compatible with a very large range of sign depths. Shorter or longer adjustment screws 412 can be swapped in/out of scissor arms 410 to vary the range of compatible sign depths even further. Front and side view schematics of an installed LED module 100 according to an embodiment of the present invention are provided in FIGS. 8A and 8B , respectively. Once the LED module 100 is affixed to the sign housing using the mounting mechanism 400 , power supply 116 is electrically connected to the sign's electrical supply. As discussed previously, this can be done by hard wiring power supply 116 directly to LED module 100 . Within such embodiment, if additional space is needed, socket 200 may be removed from the sign. Alternatively, power supply 116 can obtain power directly from socket 200 via power cord 118 , which negates the need for any hardwiring. It is to be understood that the present invention is not limited to the embodiment(s) described above and illustrated herein, but encompasses any and all variations falling within the scope of the appended claims. For example, as is apparent from the claims and specification, not all method steps need be performed in the exact order illustrated or claimed, but rather in any order that achieves the retrofit of LED lamps within conventional fluorescent lamp housings.
A method and device for replacing a fluorescent tube lamp with an LED lamp. The LED lamp includes an elongated electrical assembly having ends terminating in first and second electrical connectors, and a plurality of LEDs mounted to the elongated electrical assembly. Mounting adaptors connect with the first and second electrical connectors, and have protruding pins to connect with conventional lamp socket connectors. The mounting adaptors have rotating connectors for connecting with the first and second electrical connectors of the LED lamp, so that the LED lamp orientation can be rotated after the LED lamp is fully mounted to the lamp socket connectors.
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This is a Divisional Application of Ser. No. 08/826,656 now U.S. Pat. No. 5,943,690, filed on Apr. 7, 1997 and issued on Aug. 24, 1999. BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to data storage apparatus for use in computer systems. 2. Description of the Prior Art It is known in a computer data storage system to divide the available data storage into a plurality of physical drives, each drive providing a data storage space. A single physical drive may be partitioned to provide different spaces on the drive and/or to create "logical drives". It is known to allocate data to the resultant spaces by giving the spaces names such as A, B, C, D, etc and allocating data to them according to names (A, B, C, D) manually chosen using e.g. a keyboard or pointing device. This is done in DOS, WINDOWS and for networks NOVELL Netware, for example. (DOS, WINDOWS and NOVELL are TradeMarks). Such allocation of data takes no account of the need to quickly access the data with substantially equal ease of access to wherever it is stored. SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided a data storage apparatus having a plurality p of data storage spaces for the storage of sets of data, and allocation means for allocating the sets of data to the p spaces, the allocation means determining for each space p an allocation factor Qp where Qp=Σf(ai,xi) where the xi(i=1 ton) are a predetermined set of variables which influence the ability of a space p to store a data set at the time the set is to be allocated to the space and to allow the data set to be read out, and ai are weighting factors for weighting the variables according to a predetermined ranking of the relative importance of the variables, the Qps of the spaces p being compared and the data being allocated to a space p in dependence upon the comparison. In an embodiment of the invention, Qp=Σai(xi).sup.2 or Σai(xi) and data is allocated to the one of the spaces p having the lowest value of Qp. xi are for example: x 1 --measure of unused space in space p x 2 --measure of data sets stored in space p x 3 --measure of available channels for accessing space p x 4 --measure of number of times a space p is scheduled for reading data out and/or writing data in. Thus, the invention allows data to be automatically allocated amongst spaces p, by comparing the Qp's of the spaces and selecting the best (e.g. the lowest value of Qp). Thus data is allocated efficiently to the spaces and is allocated in a way maximising the efficiency of access to it. The variable x 1 will act with a tendency to evenly distribute the amount of data amongst the spaces p. Variable x 2 will act with a tendency to evenly distribute the number of data sets amongst the spaces p. Variable x 3 will act to allocate data according to the access bandwidth available. Variable x 4 will act to allocate data according to the expected usage of a space. The weighting factors weight the variables in a predetermined ranking. The weighting factors are chosen by the system designer so that the designer can balance the influences of the various variables xi on allocation. The invention allows, for example, data sets to be allocated to a plurality of spaces so that all data sets can be accessed efficiently from all the spaces p. Although four particular variables x 1 to x 4 have been discussed, other variables may affect the efficiency of accessing data storage space. The present invention allows any number of variables to be taken into account. According to another aspect of the invention, there is provided data storage apparatus comprising a plurality p of data storage spaces for the storage of sets of data, and allocation means for allocating the sets of data to the p spaces, according to usage indices of the spaces, the indices of the usage of the spaces being indicative of the ability of the apparatus to transfer data in different modes of operation. In a preferred embodiment of the invention the data storage apparatus accords with both of the said aspects of the invention. The usage indices represent a numerical model of the data storage apparatus and the apparatus is controlled in accordance with that model. The said another aspect of the invention allocates data to that one of the p spaces which at the time of allocation, has resources available to allow the transfer. Thus, it allows data to be transferred to a space p in accordance with the value Qp, only if that space p has the resources available to allow the transfer. In one example of the invention, the data is video data. In that example the modes of use include for example, idle, (i.e. unused), record, and playback. Playback may be at various speeds, e.g. 1×, 2×, 4× normal speed. Other modes discussed hereinafter may exist. Each space p may have a plurality of input/output channels, each of fixed bandwidth. Idle makes no use of the space and of the bandwidth of the channels. Playback may use one or more output channel, with 4× playback using the entire bandwidth of an output channel, slower playback using less. Record similarly uses at least one input channel. Some modes of operation may use two or more channels. Furthermore, one or more channels may be defective. The useage indices may be used to determine which combinations of modes of operation of a storage space can occur simultaneously. For that purpose the apparatus comprises scheduling means for storing a schedule of transfers of sets of data to/from the spaces p, the transferring means transferring data to and/or from a space p at a particular time if, the sums of corresponding useage indices associated with the transfers scheduled for that particular time are all less than respective predetermined values. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will be apparent from the following detailed description of illustrative embodiments which is to be read in connection with the accompanying drawings, in which: FIG. 1 is a schematic block diagram of a video signal recording and reproducing system in which illustrative data storage apparatus of the present invention is useable. FIG. 2 is a schematic block diagram of illustrative data storage apparatus according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an illustrative system in which video signals from a variety of sources 1 are routed by a router 2 optionally via an encoder 3 to data storage 4 where the encoded video is stored. Stored video is played back via a decoder (if encoded) and routed by another router 6 to one of a plurality of output channels 7. Some of the channels 7 may be feeds to broadcast facilities. Others of the channels may be to video processing such as editing. For editing, the channels 7 may be input/output channels allowing the reading of video from storage 4 and the writing of edited video back to the store 4. The system is controlled by a control 8 comprising one or more computers which maintain directories of the files of video data stored in storage 4. The control 8 also maintains a schedule of expected times at which video from the sources 1 are to be recorded on the data storage and of expected times at which video is to be played back (e.g. for broadcast) from the storage. The control 8 controls the recording and playback in accordance with the schedule. The sources 1 may comprise satellite links, 11, video tapes 12 and video stored in an archive 13. FIG. 2 shows an example of the data storage 4 of FIG. 1. In this illustrative example, data storage comprises two RAIDs 40 and 41. Each RAID has a RAID controller 42, 43 which responds to control signals from the system control 8 to control writing in (recording) of video signals onto the RAID and read-out (playback) of video signals from the RAID. Each RAID controller 42, 43 has a single input channel 421, 431 for receiving video to be recorded and a plurality (e.g 4) of output channels 422, 432 for the playback of video from the RAID. The 4 output channels allow the simultaneous playback of 4 channels of video from the RAID. Each RAID controller 42, 43 receives control signals from the system control 8 via two control channels 423, 433. For the purpose of this example each RAID 40, 41 in its entirety is a storage space. Thus, there are p=2 such spaces. There may be more than 2 spaces: p being an integer equal to or greater than 2 in general. In addition to maintaining directories of files, i.e. names of files and addresses of the files on the storage spaces, it is desired that the files are stored so as to be efficiently accessed. It is recognised herein that many factors influence the efficient accessing of files stored in the RAIDs 40, 41. The factors which are considered in this example are: a) a measure x 1 of unused space x 1 available on a RAID, b) a measure x 2 of the number of files stored on a RAID, c) a measure x 3 of the number of input and output channels available to record and replay files, d) a measure x 4 of the number of bookings for record/replay or other mode of operation scheduled for a RAID. Other criteria could be considered, including the bandwidths of the channels, and total file size. The system control can ascertain the unused space (x 1 ) and the number of files (x 2 ) allocated to a RAID from the directory. The number of available channels (x 3 ) in principle is a known fixed number being dependent on the hardware. In practice, faults may reduce the number of channels so x 3 may be variable. If the system control has appropriate monitoring systems, it can detect how many channels are available. The number of bookings (x 4 ) for record/playback from a RAID is ascertained by the system control from the directory and the schedule. In accordance with this example of the invention, the system control calculates for each RAID a value Qp. Qp=a.sub.1 x.sub.1 +a.sub.2 x.sub.2 +a.sub.3 x.sub.3 +a.sub.4 x.sub.4 where x 1 to x 4 are normalised parameters, not simply absolute counts of space, files, channels and bookings. x 1 to x 4 are normalised because the corresponding absolute counts produce numbers whose magnitudes are very different. For example, the space available may be millions of bytes whereas the channels available may be less than ten. In this example: ______________________________________x.sub.1 = available space on RAID p total space available on all raids x.sub.2 = number of files on RAID p total number of files in system x.sub.3 = number of channels of RAID p maximum number of channels per RAID x.sub.4 = number of bookings of RAID p total number of current bookings for all RAIDS______________________________________ Thus x 1 to x 4 are all less than or equal to one. They are also positive numbers. Available space=total space on RAID-bad sectors-used space. a 1 to a 4 are chosen to rank the measures x 1 to x 4 . Thus, if x 1 is chosen to be the most important criterion, a 1 is made larger than a 2 to a 4 . The system control compares the Qps of the spaces and a file is allocated by the system control to the RAID having the lowest value of Qp. Alternative functions for Qp include: Qp=Σai(xi).sup.2 Qp=Σai|xi| where | xi | is the absolute value of xi i=1 to n and is an integer which would be used if any parameter xi could have a negative value. In another example Qp=ax.sub.1 '+bx.sub.2 '+cx.sub.3 ' ______________________________________where x.sub.1.sup.' = unused space on a RAID total space x.sub.2.sup.' = total number of files on a RAID total number of files in system x.sub.3.sup.' = current total bookings on a RAID total bookings on all RAIDs______________________________________ and a to c are weighting factors corresponding to a i . In addition to, or as an alternative to, allocating a file to a RAID in accordance to Qp as discussed above, files may be allocated according to usage indices. A RAID, even if it has the lowest Qp, may be unable to accept a file at a particular time because it is being used. Consider RAID 40 and its controller 42. The controller has one input channel 421 of fixed bandwidth, four output channels 422 also of fixed bandwidth and two data transfer channels 424 between the RAID 40 and controller 422 and two control channels 423, e.g. RS422 channels. The RAID has plural modes of operation, such as record at various speeds, playback at various speeds, edit when used with a video editor, erase and idle. The following Table 1 sets out a set of usage indices which represent a numerical model of the RAID 40 and its controller 42. TABLE 1______________________________________RAID Usage Session Mode (Device B/W) Control Input Output______________________________________Idle 0 0 0 0 Control Y.sub.1 Y.sub.2 Y.sub.3 Y.sub.4 Play ×1 25 0 0 25 Play ×2 50 0 0 25 Play ×4 100 0 0 25 Record 25 0 100 0 Record ×2 50 0 100 0 Record ×4 100 0 100 0 Erase 0 0 0 0______________________________________ The numbers in the table represent percentages of the various RAID resources which may be used in each mode. The resources are: Input--representing the input channel Output--representing the output channels Control--representing the bandwidth of the control channels to the controller. Session--representing the bandwidth of the data transfer channels linking the controller and the RAID. By way of explanation, idle and erase use none of the resources so all values of resource are zero. Play x1 uses one output channel of 4, i.e. 25% of the output channels. It also uses 25% of the bandwidth of the data transfer channels 424 of the RAID. Play x2 and Play x4 also use only one output channel but 50% and 100% respectively of the bandwidth of the data transfer channels 424. Record x1, x2, x4, uses the 1 input channel: i.e. 100% of the input resource, and 25, 50 and 100% respectively of the bandwidth of the data transfer and channels. Control as a mode is, for example editing of video where the control channels 423 are used to control the operation of the controller 42 and RAID 40. An edit operation at normal speed where data is output uses one of four outputs Y 4 =25%, Y 1 =25% of the data transfer bandwidth and Y 2 =50% of the bandwidth of the control channels for controlling the RAID. Because data is output only Y 3 =0. The numbers given in Table 1 are examples only and would change depending on the hardware and the bandwidths of the signals to be recorded/played back, and the control functions being implemented. Providing the usage index is less than 100% for all categories, then the RAID has spare capacity for other functions. Thus, playx1 has an index (25, 0, 0, 25) and so in principle a file can be recorded at the same time as playxl occurs. As discussed above bookings for record/playback are recorded in a schedule by the system control. When a new booking for a particular mode of operation is to be made, reference is made to the schedule for other bookings occurring at the same time as the new booking. The useage indices for the bookings of a space p are derived from the Table 1 and added together. If the value of the sum of the bookings including the new booking for the space p are less than (100, 100, 100, 100) for (Session, Control, Input, Output) respectively then the new booking may be allocated to the space p. As discussed so far, the numbers given in the Table 1 are assured to be percentages of the actual resource available as defined by the hardware for real signals. The numbers of the Table may be adjusted so as to define predetermined modes of operation which are allowed to occur and disallow others. For instance, Play x1 and Play x2 together are allowed by Table 1. If the session and/or output numbers are increased so that they sum to greater than 100, Play x1 and Playx2 together would be disallowed. The invention is not limited to the foregoing examples. There may be more than p=2 RAIDS, each defining a storage space. Each RAID may be partitioned or otherwise divided into 2 or more logical drives, or volumes. Thus, one RAID may define more than one storage space. The storage spaces may be provided by storage devices other than RAIDS, having magnetic discs, such as magneto-optical (MO) disc drives. The data stored may be other than video data. Where both Qp and usage indices are needed, Qp may be determined before or after the usage indices are determined to allocate a file to a storage space. The allocation of data using Qp spreads the data across the spaces p. The usage indices indicate whether a space p is capable of storing the data at the time of allocation. It is desirable to use the spaces p efficiently to maximise the data storage capacity. Thus in a preferred embodiments the allocation means, in addition to allocating data sets to the spaces p in accordance with the said factors Qp, allocates the data sets in accordance with at least one other criterion. As an example of such another criterion, where residual space is available in one of the spaces p which can be filled by a filed, that residual space is used instead of allocating according to Qp. In this way, the unused space on a nearly full space is minimised and available space maximised in the other space(s) p. Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope and spirit of the invention as defined by the appended claims.
A data storage apparatus has a plurality p of storage spaces for storing sets of data. Each of the spaces has: available (unused) space x 1 for storage; a number x 2 of data sets already stored; a number x 3 of channels available for transferring data to the space; and a number x 4 of times the space is scheduled to be used for reading out sets of data therefrom. An allocation factor Qp=f(ai, xi) is calculated for each space where ai are weighting factors ranking xi in order of importance. A data set is allocated to the space having the "best" (e.g. lowest) value of Qp at the time the data is to be allocated. Once allocation factors determined, then data may be allocated according to usage indices representing the ability of a space to store the data at the time of allocation.
8
REFERENCES CITED [0001] [0001] U.S. Patent Documents 3173161 March., 1965 Amsbry 280/609. 3707296 December., 1972 Palazzolo et al 280/610. 4140326 Febuary., 1979 Huber 280/87. 4295656 October., 1981 Moore 280/87. 4697821 October., 1987 Hayashi et al 280/609. 4972868 December., 1990 Morris 280/609. 5005853 April., 1991 Lampl 280/610. 5080382 January., 1992 Franz 280/87. 5238260 August., 1993 Scherubl 280/610. 5320378 June., 1994 Wiig 280/610 6059307 May., 2000 Western 280/609. 6182986 Febuary., 2001 Smith 280/87.042. BACKGROUND TO THE INVENTION [0002] Since the invention of the skateboard, skateboarding has been growing widely and steadily in popularity. Skateboarders have been steadily performing more aggressively. Maneuvers and tricks have been increasing intricately in technical difficulty. [0003] A very important consideration in the development of the skateboard deck has been to make stronger, lighter and more resilient decks. It is widely known that the skateboard deck has been constructed of layers of wood ply laminations, along with the construction of placing cores of fiberglass, other materials and cores covered with fiberglass. These attempts have been to lighten and improve the strength of the skateboard deck. The purpose of these improvements is to enable the skateboarder to continually improve his or her ability in performing maneuvers. [0004] Skateboard decks are continually exposed to high impact stress. Due to this impact stress, skateboard decks are continually breaking. The integrity of the deck is constantly being breached, and as a result of this, skateboarders are being forced to purchase skateboard decks more often and are being exposed to serious injury. [0005] Known prior art includes U.S. Pat. No. 3,844,576; U.S. Pat. No. 4,412,687; U.S. Pat. No. 4,523,772; U.S. Pat. No. 5,005,853; U.S. Pat. No. 5,649,717: U.S. Pat. No. 5,759,664; U.S. Pat. No. 5,803,478; U.S. Pat. No. 5,855,389; U.S. Pat. No. 6,182,986. [0006] While these U.S. Patents probably fulfill their respective objectives and requirements, the aforementioned patents do not produce a skateboard deck that is lighter, stronger and more resilient for the skateboarder all at the same time. [0007] In this respect, the skateboard deck in this new construction placement formula substantially increases the strength, resilience and lightens the overall skateboard deck with the resiliency and strength being the focus of the invention. SUMMARY OF INVENTION [0008] This is an improved method of constructing a skateboard deck provided for all uses of a skateboard with the primary focus of the fundamental improvements being first in the performance and the endurance of the skateboard deck. This improved skateboard deck will allow for the skateboarder to more aggressively perform maneuvers without having to constantly consider the ability of the skateboard deck to perform without a serious breach in the integrity of the deck. [0009] One of the primary objectives of this innovative design is to improve the strength, endurance and resiliency of the skateboard deck. Eliminating wood plies and replacing the wood plies with layers of First Quality Carbon Fiber/Kevlar Hybrid Woven Fabric along with precise placement of Titanium Strip (s) accomplishes this. By installing these non-wood materials precisely according to the design on top and in between the wood plies increases the overall skateboard deck strength and resiliency and to reduce and or eliminate the possibility of the deck snapping. [0010] Another objective of this design is to lighten the overall skateboard deck, thus enabling the skateboarder to more easily perform the intricate maneuvers being attempted each time the skateboarder gets on his or her skateboard. This will also allow the professional and amateur skateboarders to continually create new and more technical maneuvers so as to further progress the sport. [0011] And still another objective, which is obtained by this design, is the direct application of Hook's Law, (which states specifically that if an applied force separates or causes to separate the molecules to the extent that they are unable to return to their original positions, the material is permanently deformed or broken apart). Wherein the exact placement of the non-wood material, specifically, the First Quality Carbon Fiber/Kevlar Hybrid Woven Fabric and the Titanium Strip (s), creates the design feature that wherein the final product produces a continuous spring effect. This spring effect is created by the placement of the Titanium Strip (s) exactly in the center of the skateboard deck laminations exactly centered over, along side and between the truck placement drill holes for the truck bolts. By applying Newton's Second Law, the placement of the Titanium Strips in this location, in combination with the First Quality Carbon Fiber/Kevlar Hybrid Woven Fabric, (when the applied force, the product of mass and velocity; symbol p, units kg.m/s; a vector quantity. ‘Force equals the rate of change of momentum with time, an essential principle in physics) the impact, which is the weight of the skateboarder that creates the load which is placed on the skateboard deck, the load being the impact of the skateboarders weight which occurs when the skateboarder performs maneuvers that places the load of the skateboarder on either end or in the center of the skateboard deck, the Titanium Strips working in conjunction with the bolts of the trucks helps prevent the skateboard deck from being brought to the limit of the skateboard deck's elasticity, therefore preventing the skateboard deck's integrity from being breached. These Titanium Strips and First Quality Carbon Fiber/Kevlar Hybrid Fabric in combination substantially increase the overall strength and resiliency of the skateboard deck and in doing so also lighten the skateboard deck. DETAILED DESCRIPTION [0012] Exactly what I am doing is adding high tech high strength components to the already established process to laminating a skateboard deck. What precisely is being done is placing at strategic locations of the skateboard deck after determination based on the width and length of the skateboard deck by the formula: (p/2×3−L+1 wherein “p” is the number of wood layers and “L” is the overall length of said skateboard deck, the width of the non-wood layers for skateboard decks with four and five layers of wood being determined by the formula w/3×2+1 wherein “w” is the overall width of said skateboard deck and the width of non-wood layers for skateboard decks with six or more layers of wood being determined by the formula w/3×2−1 wherein “w” is the overall width of said skateboard deck.) This formula determines the length and width of the carbon fibre/kevlar hybrid fabric. What we then do is to make a cartridge by using epoxy that encases the fabric so that adhesion is possible when placing these cartridges between or on top of the laminated wood plys. Then the normal laminating process is then completed. Because of the high tensile strength of the fabric the application of Hooks Law takes affect (which states specifically that if an applied force separates or causes to separate the molecules to the extent that they are unable to return to their original positions, the material is permanently deformed or broken apart). I also add a strip of Titanium Metal in the center of the skateboard deck during the laminating process, (Refer to the FIGS. T- 1 thru T- 5 ) When this process is completed and the holes are drilled for the truck mounting, the drill holes go directly thru the titanium metal. When the trucks are mounted the skateboard becomes even stronger. As the rider stresses the skateboard deck the titanium works in conjunction with the truck bolts to prevent the skateboard deck from reaching it point of breach. BRIEF DESCRIPTION OF THE DRAWINGS [0013] [0013]FIG. 1 represents a center cross-section side view of deck design 1 showing the five layers of wood and four layers of non-wood material and the order of their placement. [0014] [0014]FIG. 2 represents a center cross-section side view of deck design 2 showing the six layers of wood and three layers of non-wood material and the order of their placement. [0015] [0015]FIG. 3 represents a center cross-section side view of deck design 3 showing the seven layers of wood and two layers of non-wood material and the order of their placement. [0016] [0016]FIG. 4 represents a center cross-section side view of deck design 4 showing the seven layers of wood and two layers of non-wood material and the order of their placement. [0017] [0017]FIG. 5 represents a center cross-section side view of deck design 5 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 1 . [0018] [0018]FIG. 6 represents a center cross-section side view of deck design 6 showing the five layers of wood and three layers of non-wood material and the order of their placement. [0019] [0019]FIG. 7 represents a center cross-section side view of deck design 7 showing the six layers of wood and two layers of non-wood material and the order of their placement. [0020] [0020]FIG. 8 represents a center cross-section side view of deck design 8 showing the six layers of wood and two layers of non-wood material and the order of their placement. [0021] [0021]FIG. 9 represents a center cross-section side view of deck design 9 showing the six layers of wood and two layers of non-wood material and the order of their placement. [0022] [0022]FIG. 10 represents a center cross-section side view of deck design 10 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 1 . [0023] [0023]FIG. 11 represents a center cross-section side view of deck design 11 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0024] [0024]FIG. 12 represents a center cross-section side view of deck design 12 showing the four layers of wood and three layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0025] [0025]FIG. 14 represents a center cross-section side view of deck design 14 showing the seven layers of wood and two layers of non-wood material and the order of their placement. [0026] [0026]FIG. 15 represents a center cross-section side view of deck design 15 showing the four layers of wood and three layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0027] [0027]FIG. 16 represents a center cross-section side view of deck design 15 showing the four layers of wood and three layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0028] [0028]FIG. 17 represents a center cross-section side view of deck design 17 showing the four layers of wood and three layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0029] [0029]FIG. 18 represents a center cross-section side view of deck design 18 showing the five layers of wood and two layers of non-wood material and the order of their placement. [0030] [0030]FIG. 19 represents a center cross-section side view of deck design 19 showing the six layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 1 . [0031] [0031]FIG. 20 represents a center cross-section side view of deck design 20 showing the six layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 2 . [0032] [0032]FIG. 21 represents a center cross-section side view of deck design 21 showing the six layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip is placed, see FIG. T- 3 . [0033] [0033]FIG. 22 represents a center cross-section side view of deck design 22 showing the six layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 5 . [0034] [0034]FIG. 23 represents a center cross-section side view of deck design 23 showing the six layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip are placed, see FIG. T- 4 . [0035] [0035]FIG. 24 represents a center cross-section side view of deck design 24 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip are placed, see FIG. T- 4 . [0036] [0036]FIG. 25 represents a center cross-section side view of deck design 25 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips are placed, see FIG. T- 5 . [0037] [0037]FIG. 26 represents a center cross-section side view of deck design 26 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips is placed, see FIG. T- 1 . [0038] [0038]FIG. 27 represents a center cross-section side view of deck design 27 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips is placed, see FIG. T- 2 . [0039] [0039]FIG. 28 represents a center cross-section side view of deck design 28 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip is placed, see FIG. T- 3 . [0040] [0040]FIG. 29 represents a center cross-section side view of deck design 29 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip is placed, see FIG. T 4 . [0041] [0041]FIG. 30 represents a center cross-section side view of deck design 30 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strips is placed, see FIG. T- 1 . [0042] [0042]FIG. 31 represents a center cross-section side view of deck design 31 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip is placed, see FIG. T- 2 . [0043] [0043]FIG. 32 represents a center cross-section side view of deck design 32 showing the five layers of wood and two layers of non-wood material and order of their placement and the layer, in which the Titanium strip is placed, see FIG. T- 3 . [0044] [0044]FIG. 33 represents a center cross-section side view of deck design 33 showing the five layers of wood and one layer of non-wood material and order of its placement and the layers in which the Titanium strips are placed between, see FIG. T- 1 . [0045] [0045]FIG. 34 represents a center cross-section side view of deck design 34 showing the five layers of wood and two layers of non-wood material and order of it's placement and the layers in which the Titanium strip are placed between, see FIG. T- 4 . [0046] [0046]FIG. 35 represents a center cross-section side view of deck design 35 showing the five layers of wood and one layer of non-wood material and order of its placement and the layers in which the Titanium strips are placed between, see FIG. T- 5 . [0047] [0047]FIG. 36 represents a center cross-section side view of deck design 36 showing the five layers of wood and one layer of non-wood material and order of its placement. [0048] FIG. T- 1 represents a cross section top view of the laminated layer, which has two Titanium Strips, installed. [0049] FIG. T- 2 represents a cross section top view of the laminated layer, which has four Titanium Strips, installed. [0050] FIG. T- 3 represents a cross section top view of the laminated layer, which has one Titanium Strip, installed. [0051] FIG. T- 4 represents a cross section top view of the laminated layer, which has one Titanium Strip, installed. [0052] FIG. T- 5 represents a cross section top view of the laminated layer, which has two Titanium Strips, installed.
An improved skateboard deck and method of making the same consisting of laminations of wood, Non-wood, (First Quality Carbon Fiber (Warp Direction) & Kevlar Hybrid Fabric) & (Kevlar Fabric) and Metal (Titanium Strips). The lamination of the three or more materials, one material being wood, the other material being non-wood ply's and another material being metal constructed and positioned precisely according to design specifications and placed in accordance to their respective lengths and widths according to their exact determined length and widths and the order in which the materials are placed will structurally enhance the laminated wood skateboard deck. With the combination of the combined materials with their physical properties being so different and placed between the wood ply's in their respective placement and order will yield a superior final product, being a laminated skateboard which is safer, lighter, stronger and more flexible, virtually more unbreakable than any previous wood and non-wood designed skateboard.
0
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an alloy material, and particularly to a process for producing a lithium-containing alloy material. [0003] 2. Related Art [0004] Lithium material is a metal having the lowest density (the density of lithium is 0.534 g/cm 3 ), which makes the density of its alloys relatively decreased, and it is thus a most preferable candidate in the production and design of lightweight structural components. However, lithium is a very active element, has a low melting point (the melting point of lithium is 180.54° C.), and is very easily oxidized and volatilized when being heated, but the melting points of alloy elements added in lithium alloys are much higher than that of lithium, so that the melting of lithium alloys is extremely difficult. [0005] The traditional melting process of lithium alloys uses a vacuum induction melting (VIM) technique, which can be generally divided into two methods, forward feed and backward feed. The melting technique with forward feed includes the steps of (1-1) evacuating the induction melting furnace (10 −1 to 10 −5 Pa) to clean the chamber in the induction melting furnace; (1-2) placing a lithium lump into a crucible which is placed in the chamber of the induction melting furnace, induction heating at low power, and continuously evacuating to completely remove the gas in the chamber; (1-3) charging argon into the chamber, and increasing the heating power, to melt the lithium lump at such a high temperature that can melt other alloy material, for example, the melting temperature of metals such as titanium, aluminum, manganese and magnesium; and (1-4) then continuously adding the alloy material to the molten lithium material for fusion, thereby forming a lithium alloy melt. The alloy material directly settles to the bottom of the crucible due to having a higher specific gravity than that of the lithium material, at this time, the impurities attached to the surface of the alloy material such as moisture and oil stain will enter into the molten lithium material jointly, such that contaminants such as oxygen, hydrogen or carbon are present in the molten lithium material, causing the formation of the compounds such as lithium oxide or lithium carbide in the lithium alloy melt. [0006] It is particularly emphasized here that lithium oxide or lithium carbide has a specific gravity similar to that of the lithium alloy melt, and is mixed into the lithium alloy melt, so that lithium oxide and lithium carbide cannot be gravitationally separated from the lithium alloy melt; moreover, when hydrogen is solid-dissolved into it, the lithium-containing alloy melt will become further stable, so once the lithium alloy melt is contaminated, it will be very difficult to completely remove the contaminants; in (1-5), the only way is raising the temperature by further increasing the power while extending the time, in order to achieve complete fusion of the alloy materials settled to the bottom of the crucible and the molten lithium, however, this can not only cause more lithium to volatilize, but also cause the molten lithium material to absorb more contaminants, leading to a failure of uncontrolled component; in (1-6), after completely fusion (actually, it is difficult to perceive non-molten solid lump that settles to the bottom of the crucible), the lithium alloy melt is allowed to stand for a while and poured into a mold where it is allowed to cool to form an ingot, thereby finishing the production of a lithium alloy. [0007] The melting technique with backward feed includes the steps of: (2-1) evacuating the induction melting furnace first to clean the chamber as possible; (2-2) continuously evacuating, placing high-melting point alloy material into a crucible, heating at low and then high power to melt it, and maintaining at a quite high temperature, until the alloy material is completely melted; (2-3) charging argon, and then placing a lithium material into the crucible in which the lithium material is melted due to intense heat, and floats to the uppermost layer where contamination very easily occurs, however, due to the vast difference in specific gravity between the alloy material and the lithium material (the density ratio is about 3-20), a more longer fusion time is required, so that the problems of contamination and component volatilization caused by too longer fusion time and overheat cannot be avoided at all; and (2-4) standing for a while and then pouring into a mold to form an ingot after complete fusion of the lithium alloy melt. [0008] In summary, in the conventional lithium alloy melting techniques, the vacuum induction melting technique requires that the lithium material must be heated to the melting temperature of the alloy material first, and maintained at such a temperature for a long time to ensure complete dissolution of the alloy material added later. Due to the vast difference in melting point between the lithium material and the alloy material, the lithium material is volatilized in such high temperature environment, causing the content of lithium material in the lithium alloy unable to be controlled efficiently, and the loss of lithium material. Moreover, in the conventional technique, direct addition of the alloy material into the molten lithium material can easily cause the molten lithium material to be contaminated by the impurities attached to the surface of the alloy material, therefore, there exists a problem that contaminants are present in the lithium alloy melt, thereby causing uncontrolled component to make a failure in the lithium alloy production. [0009] Furthermore, in the melting technique with backward feed, because the difference in specific gravity between the lithium material and the alloy material is very high, in the addition of the lithium material into the alloy melt, the molten lithium material will float to the uppermost layer of the alloy melt, and the risk of contamination of the lithium material increases since the lithium material is unable to be wrapped by the alloy melt and thus exposed out of the surface of the alloy melt. Moreover, fully uniformly mixing between the lithium material and the alloy melt cannot be achieved in a short time because the lithium material is unable to settle into the alloy melt, and a uniformly mixed lithium alloy can only be obtained by extending the fusion time between them. [0010] Therefore, all the conventional lithium alloy melting techniques cannot avoid the problems of contamination and uncontrolled component caused by long overheat, to make the whole process uncertain, resulting in the quality of the lithium alloy unable to be improved efficiently. SUMMARY OF THE INVENTION [0011] The present invention is directed to a process for producing a lithium-containing alloy material, to improve the problems occurred in the conventional manufacture process of lithium alloys that the volatilization of lithium material in high temperature environment leads to the loss of lithium material, and uncontrolled component content of lithium material in the produced lithium alloy, as well as the problem that when being fused with the alloy material, the lithium material is easily contaminated with impurities and thus contaminants are present in the lithium alloy resulting in a failure in lithium alloy production, and also improve the inefficient mixing between the lithium material and the alloy material due to the difference in specific gravity, and the problem that a uniformly fused lithium alloy can be obtained only after long time fusion. [0012] The present invention discloses a process for producing a lithium-containing alloy material, including (1) placing at least one alloy element into a crucible in a vacuum induction melting furnace; (2) melting the alloy element into an alloy melt by induction heating in the vacuum induction melting furnace; (3) pouring the alloy melt into a ladle protected with an inert gas and pre-filled with a lithium material; (4) shaking the ladle, to vigorously flush and mix the lithium material with the alloy melt, thus forming a molten lithium alloy; and (5) pouring the molten lithium alloy into a mold to form an ingot, thereby forming a lithium alloy. [0013] In the process for producing the lithium-containing alloy material disclosed in the present invention, the step (2) includes evacuating the vacuum induction melting furnace, to induction heat the alloy element in a vacuum environment. [0014] In the process for producing the lithium-containing alloy material disclosed in the present invention, the step (2) includes induction heating the alloy element in atmospheric environment. [0015] In the process for producing the lithium-containing alloy material disclosed in the present invention, a pre-heating step of the ladle is further included before the step (3). [0016] In the process for producing the lithium-containing alloy material disclosed in the present invention, the step (4) includes strengthening the stirring of the alloy melt and the lithium material by means of an agitating apparatus. [0017] In the process for producing the lithium-containing alloy material disclosed in the present invention, the agitating apparatus is a vibrator. [0018] In the process for producing the lithium-containing alloy material disclosed in the present invention, the agitating apparatus is an induction coil. [0019] In the process for producing the lithium-containing alloy material disclosed in the present invention, the alloy element is one selected from the group consisting of aluminum, magnesium, manganese, zirconium, zinc, titanium, scandium, yttrium, copper, silver, and silicon, or a mixture thereof. [0020] In the process for producing the lithium-containing alloy material disclosed in the present invention, the alloy element is magnesium, to produce a lithium-magnesium alloy by melting. [0021] In the process for producing the lithium-containing alloy material disclosed in the present invention, the alloy element is aluminum, to produce a lithium-aluminum alloy by melting. [0022] The process for producing the lithium-containing alloy material disclosed in the present invention includes placing the alloy element into a vacuum induction melting furnace and melting it by heating to form an alloy melt, by which the contaminants attached to the surface of the alloy element can be completely removed, so as to avoid the contamination of the lithium material by the contaminants. Then, the alloy melt is poured into a ladle protected with an inert gas and pre-filled with the lithium material, where the lithium material is flushed and mixed with, and wrapped by, the alloy melt, such that the lithium material is diffused into the alloy melt while being melted. Therefore, in addition to the avoidance of the contamination of the lithium material by protection with the alloy melt, uniformly mixing of the lithium material with the alloy melt and significant reduction of the mixing time are also achieved, thereby a high quality lithium alloy material is obtained. [0023] The description on the content of the present invention above and the description on the embodiments below are used to exemplify and explain the principle of the present invention and provide further explanation on the claims of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0024] No drawings. DETAILED DESCRIPTION OF THE INVENTION [0025] In order to make the content of the present invention more comprehensible, the embodiments of the present invention are described below. [Embodiment 1] Melting of Lithium-Magnesium Alloy [0026] Magnesium is a very important light metal (1.74 g/cm 3 ), and can maintain the low density property of the lithium alloy if it can be added into the lithium alloy in mass, in view of this, the present invention attempts to use magnesium as the main alloy element in mixing with lithium, to produce a lithium-magnesium alloy with unprecedented performances. The process for producing the lithium-containing alloy material disclosed in the present invention includes mixing the alloy elements having high melting point such as magnesium (Mg), aluminum (Al), zinc (Zn), zirconium (Zr), scandium (Sc), and yttrium (Y) at a required weight ratio, or selecting magnesium as a single alloy element to form a magnesium-lithium alloy with lithium. In this embodiment, a plurality of alloy elements are used for the production of the lithium alloy, and a mixture of the alloy elements obtained by formulation at a required weight ratio has a higher specific gravity and melting point than those of the lithium. [0027] The alloy elements mixed at a required weight ratio are placed into a crucible in a vacuum induction melting furnace, and the induction melting furnace is evacuated to a high vacuum level (10 −1 to 10 −5 Pa), to make the alloy material in a vacuum environment. The weight proportions of each alloy materials are as shown in table 1, expressed in weight percent (wt %). [0028] The alloy material is pre-heated by induction heating at low power, so as to assist in degassing and de-fouling of the alloy material, to remove the contaminants attached to the surface of the alloy material and thus avoid the contamination to the lithium material caused by these contaminants in later steps. Then argon is introduced into the induction melting furnace, and the heating power is increased slowly, to melt the alloy material by induction heating into an alloy melt. The temperature is kept at 700° C. to 850° C. for a suitable period of time (depending on the species and amounts of the alloy elements), until the alloy elements are completely melted into the alloy melt. [0029] Then, the completely melted alloy melt is poured into a particularly sized ladle (such that the depth of the alloy melt is equivalent to the diameter of the ladle), and the ladle is pre-filled with a required amount of lithium lump. When the alloy melt is poured into the ladle, the lithium lump is vigorously flushed and mixed with a hot stream of the alloy melt, and wrapped by the alloy melt, such that the lithium material is melted and diffused into the alloy melt. At this time, the lithium material has a high diffusion property in the alloy melt due to having a lower specific gravity than that of the alloy material, so that the purpose of uniform mixing of the lithium material with the alloy melt is achieved. In such a step, the relationship among the amount of the alloy melt, temperature and the amount of lithium material should be considered in order to improve the success rate of melting of the lithium alloy. Moreover, pre-heating of the ladle can be carried out before pouring the alloy melt into the ladle, and the ladle is disposed on a vibrator or stirring is strengthened with an agitating apparatus such as electromagnetic induction coil, thereby increasing the mixing efficiency between the lithium material and the alloy melt. [0030] The lithium alloy melt formed by uniformly mixing the lithium material with the alloy melt is poured into a mold few minutes after the alloy melt is poured into the ladle, and a lithium-magnesium alloy ingot can be taken out of the mold after cooling to below 100° C. [0031] By the process for producing the lithium-containing alloy material disclosed in the present invention, the problems of contamination and uncontrolled component of the lithium material caused by longtime overheat in conventional meting technique are avoided, and a series of high-quality super-light lithium-magnesium alloys as shown in table 1 below are successfully produced, and the ingots have an outer diameter of 205 mm, a length of 500 mm, and a weight of 25 Kg. [0000] TABLE 1 Element Lithium Magnesium Aluminum Manganese Zinc Zirconium Scandium Yttrium Alloy wt % wt % wt % wt % wt % wt % wt % wt % A 5.5 93.5 — — 1   — — 0.05 B 8 91 1 — — — 0.02 — C 10 89 — 0.3 0.5 0.2 — — D 15 84 — — 1 — — — [0032] No micro-bubble is found when examining the appearance and the section exposed by cutting off the casting head for these ingots. Then these lithium-magnesium alloys are directly extruded between 180° C. and 250° C. into plates of 3 mm thick, and then examined for cold roll process. It is found that these alloys can have a rolling percent of above 50% due to their very excellent and stable forming property, and successfully rolled into thin plates (0.15 to 1.0 mm), in which the inter-annealing temperature used is 220° C. Comparison results of the mechanical physical properties between the lithium-magnesium alloys of the present invention and the light aluminum and titanium materials are summarized in table 2. [0000] TABLE 2 Physical Property Den- Elastic Tensile sity Modulus Strength Specific (ρ) (E) (σ) Elongation Damping Strength Material g/cm 3 GPa MPa (ε) % Capacity E/ρ A 1.58 45 160 25 — 29 B 1.50 44 140 40 0.05 29 C 1.43 43 120 55 0.01 30 D 1.35 43 90 70 0.01 32 Aluminum 2.71 70 9 45 0.002 26 (1100-O) Titanium 4.51 100 500 25 0.002 22 (α-Ti) [0033] All the lithium-magnesium alloys above are very applicable in loudspeaker membranes, since they have physical properties such as low density, high specific stiffness, high damping capacity, and high formability, i.e. three-high and one-low properties. As an attempt, alloy plate C of 0.15 mm thick is selected, pressed into a loudspeaker membrane, and assembled into a loudspeaker unit, which is then tested for changes in sound pressure level (SPL) curve at different frequencies in an anechoic chamber by standard test method for evaluation of loudspeakers, and compared with those of an aluminum loudspeaker of the same type. It is found that sound pressure levels at below 500 Hz are of little difference; in a bandwidth from 500 to 7000 Hz, however, the sound pressure level of the lithium-magnesium loudspeaker is more stable, and the harmonic distortion is smaller, indicating the application potential in this aspect. [Embodiment 2] Melting of Lithium-Aluminum Alloy [0034] Aluminum is also a light metal (2.71 g/cm 3 ), and also a preferable additive for the lithium-containing alloy, so a lithium-aluminum alloy is also selected in the present invention for comparison, and it has the following melting steps. Alloy materials such as aluminum (Al), magnesium (Mg), manganese (Mn), copper (Cu), titanium (Ti), zirconium (Zr), silver (Ag), zinc (Zn), and silicon (Si) are weighed out at the proportions in table 3, melted into an alloy melt at 800° C. following the step in Embodiment 1, then poured into a ladle and uniformly mixed with lithium, and poured into a mold to form an ingot, in this way, the problems of contamination and uncontrolled component caused by longtime overheat are also avoided. The ingots have an outer diameter of 205 mm, a length of about 500 mm, and a weight of about 40 Kg. Again, no micro-bubble is found when examining the appearance and the section exposed by cutting off the casting head of these ingots, and they are directly extruded at 400° C. into pipes and plates, which have an elongation of above 15% under extrusion, have cold rollability and better warm rollability, and are applicable to the design of lightweight structural materials, for example, sports equipments such as bicycle. [0000] TABLE 3 Element Lithium Aluminum Copper Magnesium Manganese Zirconium Titanium Silver Zinc Silicon Scandium Alloy wt % wt % wt % wt % wt % wt % wt % wt % wt % wt % wt % E 2.5 94 2.5 0.3 0.1 0.15 0.1 — — — 0.1 F 2.5 93 1.5 1.0 0.1 0.15 0.1 — 0.2 0.2 — G 1.5 92 5.5 0.4 — 0.15 — 0.4 — — — [Embodiment 3] Semi-Atmospheric Lithium Alloy Melting [0035] In order to further decrease the production cost of the lithium alloy, attempts are made for simplification of the melting process. The magnesium alloy melt in Embodiment 1 is melted in atmosphere by flux covering in stead, and the aluminum alloy melt in Embodiment 2 is alternatively melted in atmosphere. After the degassing (hydrogen) step is completed, both of them are transferred into a compartment protected with an inert gas, poured into a ladle pre-filled with a lithium material, uniformly mixed and then poured into a mold to form an ingot. In this way, the problems of contamination and uncontrolled component caused by longtime overheat are also avoided, and the resulting ingots have comparable quality to that of the ingots above, suggesting that the semi-atmospheric lithium alloy melting has also achieved unprecedented success. [0036] In the process for producing the lithium-containing alloy material disclosed in the present invention, the contaminants attached to the surface of the alloy elements are completely removed since the alloy elements are first placed into the vacuum induction melting furnace and melted by heating, therefore the contamination of the lithium alloy in the manufacture process is avoided. By flushing and mixing of the lithium material with the alloy melt, and diffusion of the lithium material in the alloy melt, the lithium material is melted by the heat from the alloy melt, by which the loss of the lithium material caused by volatilization of the lithium material can be prevented, and the lithium material can be further protected from contamination, and at the same time, the purposes of uniformly mixing the lithium material and the alloy melt, significantly lowering the mixing time, and producing a high-quality lithium alloy material also can be achieved.
A process for producing a lithium-containing alloy material is described. The process supplies a light alloy material applicable to the design of lightweight structural components. The process includes first melting alloy materials at a required ratio into a homogeneous alloy melt, then pouring the alloy melt into a ladle protected with an inert gas and pre-filled with a lithium material, where the lithium material is vigorously flushed and mixed with a hot stream of the alloy melt, and diffused into the alloy melt, and then after uniformly mixing, pouring the lithium-containing alloy melt into a mold to form an ingot and produce a lithium alloy. The process solves the fundamental problems of both contamination and uncontrolled component caused by longtime overheat in traditional melting techniques, and is a novel, safe, economic, and efficient manufacture process.
1
BACKGROUND OF THE INVENTION [0001] The present inventive concept relates generally to an apparatus and method of organizing documents and other tangible items, and more particularly, to an apparatus and a method comprising a wall-mounted receptacle capable of supporting additional receptacles thereon. SUMMARY OF THE INVENTION [0002] The present invention relates to a novel apparatus and method for organizing, storing or filing items including, for example, a substrate, office supplies and/or other tangible articles in one or more hanging receptacles or the like. The apparatus comprises a primary receptacle which may be mounted, for example, to a surface such as the wall of a room, cubicle, or the like. The primary receptacle may then accommodate or support one or more additional receptacles via attachment to and suspension from a attachment mechanism (e.g., a hook) that is pivotally attached to a bottom of the primary receptacle. Additional receptacles may then be successively attached in series or parallel in like fashion. While each additional receptacle may or may not be secured to the wall for additional support, a primary object of the present general inventive concept is to provide a filing apparatus having a primary receptacle that may easily accept additional units depending on a desired application of the filing apparatus, thereby increasing versatility. The retractable attachment mechanism allows adaptability and flexibility for use of the apparatus in a variety of spaces also provides aesthetically pleasing appearance, increased safety, and ease and efficiency for packaging, and shipping and storing the apparatus. [0003] A principal object of the present general inventive concept is to provide a method and system to organize items in one or more receptacles situated on a wall so that files therein may be easily indentified without requiring manual manipulation of the files. [0004] Another object of the present general inventive concept is to provide a method and system to organize files in a first receptacle unit that supports additional receptacle units each arranged successivly and depending one from another. [0005] Another object of the present general inventive concept to provide a method and system to organize files, the system having a first receptacle unit to support additional receptacle units so that only the first receptacle requires securing to a wall. [0006] Another another object of the present general inventive concept to provide a simple low-cost system to organize files and/or individual papers and for separating such files and/or papers into defined areas for easy identification and removal. [0007] Another another object of the present general inventive concept to provide a system to organize files having a number of receptacles that are efficiently designed with a front side, left and right sides, and a partial rear side that is supplemented in part by the wall. [0008] Another another object of the present general inventive concept to provide a system to organize files having a number of units each having a receptacle that is efficiently designed with a front side, left and right sides, and a partial rear side that is supplemented in part by the wall to form the receptacle. [0009] Another another object of the present general inventive concept to provide a system to organize files having a number of units with each unit being identical and self-contained so that each unit may hang from or be hung from each other. [0010] The foregoing and other objects are intended to be illustrative of the present general inventive concept and are not meant in a limiting sense. Many possible embodiments of the present general inventive concept may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of present general inventive concept may be employed without reference to other features and subcombinations. Other objects and advantages of this present general inventive concept will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this present general inventive concept and various features thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0011] A preferred embodiment of the invention, illustrative of the best mode in which the applicant has contemplated applying the principles, is set forth in the following description and is shown in the drawings. [0012] FIG. 1 is a front view of a mountable storage apparatus of the present general inventive concept illustrating an upper primary receptacle with a second identical receptacle attached to the primary receptacle, and an organizer receptacle attached to the second receptacle. [0013] FIG. 2 is a top view of the filing system of the present general inventive concept illustrating an upper primary receptacle with an interior. [0014] FIG. 3 is a side view of the filing system of the present general inventive concept illustrated in FIG. 1 . [0015] FIG. 4 is a back view of the filing system of the present general inventive concept illustrated in FIG. 1 with a rear opening to abut a wall. [0016] FIG. 5 is a perspective view of the filing system of the present general inventive concept illustrated in FIG. 1 . [0017] FIG. 6 is an exploded view of the filing system of the present general inventive concept illustrated in FIG. 1 having a business card holder, a label holder, receptacles, hooks, and an organizer. [0018] FIG. 7 is a front view of the filing system of the present general inventive concept illustrated in FIG. 1 wherein the system is assembled. [0019] FIG. 8 is a front view of a single receptacle of the filing system of the present general inventive concept. [0020] FIG. 9 is a top view of a single receptacle of the filing system of the present general inventive concept. [0021] FIG. 10 is a rear view of a single receptacle of the filing system of the present general inventive concept. [0022] FIG. 11 is a side view of a single receptacle of the filing system of the present general inventive concept. [0023] FIG. 12 is a bottom view of a single receptacle of the filing system of the present general inventive concept. [0024] FIG. 13 is a front perspective view of a single receptacle of the filing system of the present general inventive concept. [0025] FIG. 14 is a rear perspective view of a single receptacle of the filing system of the present general inventive concept. [0026] FIG. 15 is an illustration of the present general inventive concept showing an enlarged fragmentary view of an attachment hook thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0027] Reference will now be made in detail to the embodiments of the present general inventive concept, 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 general inventive concept be referring to the figures. [0028] According to the above objects, the present general inventive concept includes a wall-mounted filing system 1 . In an exemplary embodiment, the filing system 1 is configured with a primary wall receptacle 3 having a generally rectangular shape. The wall receptacle 3 includes an upper lip 10 to support, for example, a business card holder 15 to hold standard business cards and/or other like-shaped objects. The business card holder 15 may be attached to the upper lip 10 via a hook 17 molded into a back of the business card holder 15 . [0029] A label holder 16 may also be attached to the upper lip 10 via a hook 18 molded into a back of the label holder 16 so that a user may indicate a type of use for the wall receptacle 3 , e.g., if the wall receptacle 3 is used as a mailbox, a name can be assigned via the label holder 16 . In the exemplary embodiment, the label holder 16 is oval and manufactured via two pieces of molded plastic with an opening that is approximately ⅛″ slot located at the top of the holder 16 to receive and hold a piece of paper to allow the user to label the receptacle 3 . Any depending wall receptacle 3 may have its own business card holder 15 and label holder 16 . [0030] Attached to either side of a lower end 5 of the primary wall receptacle 3 are two generally u-shaped hooks 4 having an open end 7 and a closed end 8 . The open end 7 has laterally-extending points 9 that are sized and shaped to engage apertures 12 and permit rotation of the hook 4 upon engagement of the hook 4 with the receptacle 3 . [0031] The apertures 12 are located in either side of a groove 19 that extends from the lower end 5 of the wall receptacle 3 to the upper lip 10 . The u-shaped hooks 4 , once engaged within the apertures 12 , may be selectively rotated up and down between an extended position (illustrated in FIG. 1 ) and a retracted position (illustrated in FIG. 15 ). When rotated downward to the extended position, the u-shaped hooks 4 are configured to receive a mating tab 25 from an additional receptacle 30 such that each of the hooks 4 that extend from the primary receptacle 3 provides support or a mounting attachment for the tab 25 of the additional receptacle 30 . When rotated upward to the retracted position, the u-shaped hook 4 is in a collapsed or storage configuration, such that the hook 4 is effectively hidden behind the additional receptacle 30 . [0032] The u-shaped hooks 4 are made of a resilient material such as metal and have bends 22 in arms 23 to provide structural reinforcement of the u-shaped hooks and a degree of resiliency. The u-shaped hooks 4 engage the apertures 12 by pinching or compressing the hooks 4 at the arms 23 , aligning the hook points 9 with the apertures 12 , and releasing the hooks 4 so that the points 9 resiliently spring back or decompress to their original position, thereby entering the apertures 12 . [0033] Each groove 19 has four square projections 20 that extend out from a rear wall 21 of the groove 21 . The projections 20 are arranged in two rows, an upper row and a lower row, each having two of the projections 20 . The upper row is located slightly above the apertures 12 while the lower row is located slightly below the apertures 12 . The projections 20 block and otherwise restrict flexing of the u-shaped hooks 4 when the u-shaped hooks 4 are in the storage or use configuration so as to prevent undesired disengagement of the hooks 4 with the apertures 12 . The projections 20 permit flexing of the u-shaped hooks 4 only when the hooks 4 are rotated to a position that is precisely between the storage and use configuration (not illustrated) so that the u-shaped hooks 4 extend in a direction parallel to the projection direction of the projections 20 project out from the rear wall 21 . [0034] When the u-shaped hooks 4 are in the storage configuration, the u-shaped hooks rest inside the groove 19 so that a rear surface 6 of the wall receptacle 3 is generally flush to provide a planar rear surface 6 and thereby facilitate secure mounting of the wall receptacle 3 to a wall (not illustrated). [0035] When the u-shaped hooks 4 are in the use configuration, the u-shaped hooks may be used to engage an additional receptacle 30 . Specifically, each primary receptacle 3 and additional receptacle 30 are identically shaped and have a mounting tab 25 located in each groove 19 that is sized and shaped to receive the closed end 8 of the hook 4 . The tab 25 extends outward from the rear of the wall receptacle 3 and has a downwardly-protruding point to partially surround and securely engage the closed end 8 of the hook 4 . [0036] The tab 25 is entirely contained within the groove 19 and is flush with the rear surface 6 of the wall receptacle 3 to provide a planar rear surface 6 and thereby facilitate secure mounting of the wall receptacle 3 to the wall. [0037] Any number of additional receptacles 30 may be sequentially attached to each other with the primary limiting factors being space available on the wall and reach of the user required to gain access to the receptacles 3 and 30 . [0038] In the exemplary embodiment, the primary receptacle 3 is mounted to the wall, an additional receptacle 30 is attached to the first wall receptacle 3 via hooks 4 , and an organizer 40 is attached to the second wall receptacle 3 via hooks 4 . The additional receptacles 33 are interchangeable with the organizer 40 and may be arranged in any order depending on application, such as with the organizer 40 as the primary wall mount and the primary receptacle 3 depending therefrom. [0039] In the exemplary embodiment, the organizer 40 is designed exactly the same as the receptacles 3 and 30 , having hooks 4 in grooves 19 with mounting tabs 25 and having the same width as the receptacles 3 and 30 , but the organizer 40 is approximately one-third as deep as the receptacles 3 and 30 . [0040] Additionally, the organizer 40 has four removable dividers 41 within an interior thereof, however, it is foreseen that any number of dividers can be used depending on application. The dividers 41 are easily installed via the user by sliding each divider 40 between laterally extending grooves 42 located on an interior of the front and rear surfaces. The dividers 41 have a bottom surface with via two tabs 43 that extend downward and into two tab-receiver apertures 44 in the organizer 40 bottom surface to further secure the dividers 40 . [0041] In the exemplary embodiment, the primary receptacle 3 is first mounted to the wall, however, the organizer 40 may also be first mounted. On either side of an upper portion of the groove 19 in the rear wall of both the wall receptacle 3 and organizer 40 are upper apertures 49 . On the lower portion of the groove are tabs 48 having lower apertures 50 . The apertures 49 and 50 may be used to mount the wall receptacle 3 and/or the organizer 40 to the wall via screws, nails, or the like. [0042] While the lower apertures 50 are a secondary means of attachment and may not be used depending on the weight of items to be stored via the system 1 , if the lower apertures 50 are to be used, the hooks 4 must be moved to either the use configuration or the storage configuration prior to using the lower apertures 50 . After the lower apertures 50 are used to secure the wall receptacles 3 or 30 , and/or organizer 40 to the wall, the hooks 4 cannot thereafter be rotated. [0043] The wall receptacles 3 and 30 , and/or the organizer 40 have a dip 53 in the upper lip 10 to permit easy access to any contents stored therein. [0044] The wall receptacles 3 and 30 have an opening 55 in the rear wall 6 , which requires less material and provides a system 1 with increased efficiency. Because the receptacles 3 and 30 abut a wall (not illustrated), which provides a rear surface, the wall receptacles 3 and 30 can be designed with only a partial rear wall 6 . [0045] The wall receptacles 3 and 30 , and/or the organizer 40 may be manufactured in various shapes depending on application to accommodate various items [0046] While the exemplary embodiment provides hooks 4 that rotate on a horizontal axis and in two directions, i.e., up and down, it is foreseen that hooks may rotate on a vertical axis and from left to right to provide increased versatility in mounting of add-ons. [0047] Further, while the exemplary embodiment provides a vertical stacking of receptacles, it is foreseen that receptacles may extend horizontally or horizontally and vertically along a wall. In this embodiment, hooks or other like attachment means may be situated on one side or both sides of a primary receptacle to support additional receptacles on either side of the primary receptacle. The additional receptacles may also support further additional receptacles. [0048] Having now described the features, discoveries and principles of the general inventive concept, the manner in which the general inventive concept is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims. [0049] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the general inventive concept herein described, and all statements of the scope of the general inventive concept which, as a matter of language, might be said to fall therebetween.
An apparatus and method for organizing, storing, and/or filing items, with a primary receptacle that is mountable to a wall and supports additional receptacles via attachment to and suspension from a hook that is pivotally attached to a bottom of the primary receptacle.
0
[0001] This is a continuation of U.S. patent application Ser. No. 15/352,699 filed on Nov. 16, 2016, which is a continuation of U.S. patent application Ser. No. 14/363,359 filed on Jun. 6, 2014, which is the National Phase Entry of International Application No. PCT/JP2012/007776 filed on Dec. 4, 2012 which claims priority from Japanese Patent Application No. 2011-266774 filed on Dec. 6, 2011. The contents of these applications are incorporated herein by reference in their entireties. TECHNICAL FIELD [0002] The present invention relates to a storage battery relocation assistance apparatus for providing the assistance for relocating and using a storage battery and also to a storage battery relocation assistance method for the same. BACKGROUND ART [0003] In recent years, a large number of electric vehicles running with electric power from storage batteries, such as HEVs (Hybrid Electric Vehicles), PEVs (Plug-in Electric Vehicles), and EVs (Electric Vehicles), have been utilized. Examples of the storage batteries mentioned herein include a lithium ion secondary battery and a nickel hydrogen secondary battery. [0004] Electricity storage systems for supplementing electric power supply using storage batteries have been put in practical use at, for example, houses, buildings, or factories. In such electricity storage systems, storage batteries are charged with surplus generated electric power or low cost midnight electric power, while the storage batteries are used to supply electric power to electric appliances when the amount of electric power generation decreases, or during a time period when the cost of a commercial power source is high, or when electric power is in shortage. [0005] Moreover, as an example of the related art of the present invention, Patent Literature 1 discloses a power supply service system that manages the use state of the battery of a car and the customers and enables smooth charging and replacing of the battery. CITATION LIST Patent Literature [0006] PTL 1 [0007] Japanese Patent Application Laid-Open No. 2002-140398 SUMMARY OF INVENTION Technical Problem [0008] A storage battery used to run a vehicle is subject to very severe conditions, such as repetitive charging and outputting of a high current. In comparison with the use conditions, the use conditions of a storage battery in an electricity storage system in a house, for example, are moderate. [0009] Conventionally, a storage battery used in a vehicle can be technically recycled when deteriorating and no longer satisfying use conditions. More specifically, the storage battery includes rare materials, so that deteriorated storage battery undergoes a decomposing process and is then utilized as new storage battery materials. [0010] However, since a storage battery in a vehicle is subject to very severe condition, even a storage battery unusable in a vehicle often exerts sufficient performance when used in other facilities. Moreover, recycling of a storage battery requires a relatively high cost. For this reason, there arises a problem in that recycling of a storage battery usable for other facilities increases a comprehensive cost for a life cycle from manufacturing to recycling of a storage battery. [0011] It is an object of the present invention to provide a storage battery relocation assistance apparatus that can provide the assistance for relocating and using a plurality of storage batteries among a plurality of facilities to contribute to a comprehensive cost reduction for life cycles of the storage batteries and also to provide a storage battery relocation assistance apparatus method that can provide the same. Solution to Problem [0012] A storage battery relocation assistance apparatus according to an aspect of the present invention includes: a collection section that collects battery information representing a state of a plurality of storage batteries used in a plurality of facilities; a battery information storing section that stores the battery information collected by the collection section; and a deterioration prediction section that predicts deterioration of the plurality of storage batteries when the plurality of storage batteries are relocated and used among the plurality of facilities, based on the battery information stored in the battery information storing section. [0013] A storage battery relocation assistance method according to an aspect of the present invention includes: collecting battery information representing a state of a plurality of storage batteries used in a plurality of facilities, through a communication network or a storage medium; [0014] storing, in a battery information storing section, the battery information collected by the collecting; and predicting, by a deterioration prediction section, deterioration of the plurality of storage batteries when the plurality of storage batteries are relocated and used among the plurality of facilities, based on the battery information stored in the battery information storing section. Advantageous Effects of Invention [0015] According to the present invention, deterioration of a plurality of storage batteries relocated and used among a plurality of facilities is predicted, and thus determining the optimal relocation time and relocation destination of the storage battery can be assisted based on the result of prediction of deterioration. Accordingly, it is possible to make a contribution to a comprehensive cost reduction for the life cycle of a storage battery. BRIEF DESCRIPTION OF DRAWINGS [0016] FIG. 1 is a configuration diagram illustrating a whole storage battery recycle system; [0017] FIG. 2 is a data table illustrating an example of in-use battery information stored in an in-use battery information storing section; [0018] FIG. 3 is a data table illustrating an example of deterioration prediction information stored in an in-use battery deterioration prediction information storing section; [0019] FIG. 4 is a data table illustrating an example of use-destination-information stored in a use-destination-information storing section; [0020] FIG. 5 is a graph illustrating a time variation in the discharge capacity of the same storage battery charged and discharged repeatedly with a predetermined current amount; [0021] FIGS. 6A to 6C are graphs illustrating changes in deterioration curves in the case of relocation use of the storage battery; [0022] FIG. 7 illustrates an example configuration of a storage battery pack; [0023] FIG. 8 is a flow chart of a storage battery deterioration prediction process performed in an in-use battery deterioration prediction section; [0024] FIGS. 9A to 9D, 9M and 9Q are diagrams for describing various relocation models of the storage batteries; [0025] FIGS. 10A to 10C are graphs illustrating the deterioration prediction curves of the storage battery in one relocation model; [0026] FIGS. 11A to 11C are graphs illustrating the deterioration prediction curves of the storage battery in another relocation model; [0027] FIG. 12 is a flow chart of a relocation determination process performed in a relocation determination section; [0028] FIG. 13 is a table illustrating example determination requirements for relocating a storage battery; [0029] FIGS. 14A and 14B are explanatory diagrams of an example of repacking for relocating a storage battery; [0030] FIGS. 15A and 15B are explanatory diagrams of an example of repacking for relocating a storage battery; and [0031] FIG. 16 is an explanatory diagram of an example of repacking for relocating a storage battery. DESCRIPTION OF EMBODIMENTS [0032] Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. [0033] FIG. 1 is a configuration diagram illustrating a whole storage battery recycle system according to an embodiment of the present invention. [0034] The storage battery recycle system in this embodiment includes storage battery relocation assistance server 1 , a plurality of vehicles 100 , a plurality of houses 200 , a plurality of buildings 300 , a plurality of factories 400 , collected-battery warehouse 500 , and network 600 utilized for data transmission. In FIG. 1 , one each of the plurality of vehicles 100 , houses 200 , buildings 300 and factories 400 is illustrated by one representative element. [0035] In these configurations, storage battery relocation assistance server 1 corresponds to an embodiment of the storage battery relocation assistance apparatus according to the present invention, and vehicle 100 , house 200 , building 300 , and factory 400 correspond to an embodiment of a plurality of facilities using a storage battery. Configuration of Storage Battery Relocation Assistance Server [0036] Storage battery relocation assistance server 1 is a computer including, for example, a CPU (Central Processing Unit) as an arithmetic unit, a RAM (Random Access Memory) and a hard disk as storing section 20 , a communication apparatus, a display or a printer as an information output section, and an input apparatus for inputting an operational command from an operator. [0037] In storage battery relocation assistance server 1 , a software module read from the hard disk is expanded on the RAM and is executed by the CPU to implement a plurality of functional modules. More specifically, storage battery relocation assistance server 1 includes, as the plurality of functional modules, in-use battery state collection section 11 , in-use battery deterioration prediction section 12 , input section 13 for inputting information on use destinations, relocation determination section 14 , reporting section 15 , collected-battery deterioration prediction section 16 , and collected-battery state collection section 17 . [0038] Storing section 20 in storage battery relocation assistance server 1 includes in-use battery information storing section 21 , in-use battery deterioration prediction information storing section 22 , use-destination-information storing section 23 , unused-battery deterioration prediction information storing section 24 , collected-battery deterioration prediction information storing section 25 , and collected-battery information storing section 26 . [0039] This plurality of storing sections 21 to 26 stores and manages predetermined information according to predetermined formats. In-use battery information storing section 21 corresponds to an embodiment of the battery information management section according to the present invention, and use-destination-information storing section 23 corresponds to an embodiment of the requirement information management section according to the present invention. [0040] In-use battery state collection section 11 collects information (referred to as battery information) representing a state of a plurality of storage batteries used in the plurality of vehicles 100 , the plurality of houses 200 , the plurality of buildings 300 , and the plurality of factories 400 , and stores the information in in-use battery information storing section 21 . The battery information is collected always or periodically. In-use battery state collection section 11 is capable of exchanging data with the communication sections of the plurality of vehicles 100 , the plurality of houses 200 , the plurality of buildings 300 , and the plurality of factories 400 through a communication apparatus connected to network 600 . The collected in-use battery information will be described below in detail. [0041] In-use battery deterioration prediction section 12 predicts future deterioration of each storage battery on the basis of the battery information on an in-use storage battery, and stores this prediction result (referred to as deterioration prediction information) in in-use battery deterioration prediction information storing section 22 . This deterioration prediction information will be described below in detail. [0042] Input section 13 receives information, which is inputted by an operator according to a predetermined input format through the input apparatus, on each facility (referred to as use-destination-information) of the plurality of vehicles 100 , the plurality of houses 200 , the plurality of buildings 300 , and the plurality of factories 400 . Input section 13 then stores the inputted use-destination-information in use-destination-information storing section 23 . The content of this use-destination-information will be described below. [0043] Collected-battery state collection section 17 collects information representing a state of a plurality of storage batteries kept in collected-battery warehouse 500 , and stores the information in collected-battery information storing section 26 . Collected-battery state collection section 17 is capable of exchanging data with a communication section of collected-battery warehouse 500 through a communication apparatus connected to network 600 . The collected information in this case is almost the same as information collected by in-use battery state collection section 11 . [0044] Collected-battery deterioration prediction section 16 predicts future deterioration of the plurality of storage batteries kept in collected-battery warehouse 500 , and stores information on the prediction result in collected-battery deterioration prediction information storing section 25 . The details of this deterioration prediction will be described later as a supplement for prediction of deterioration of an in-use storage battery. [0045] Unused-battery deterioration prediction information storing section 24 is a storing section for beforehand storing, as deterioration prediction information, information on the future deterioration property of an unused storage battery that is kept while being unused. [0046] Relocation determination section 14 reads, from storing section 20 , the deterioration prediction information on an in-use storage battery, the deterioration prediction information on an unused storage battery, the deterioration prediction information on a collected storage battery, and the use-destination-information on each facility. Based on the above-described deterioration prediction information and information on predetermined relocation requirements for a storage battery, relocation determination section 14 then performs an optimization process and determines the optimal relocation time and relocation destination of each storage battery. [0047] That is, relocation determination section 14 determines the optimal relocation schedule for each storage battery. [0048] Reporting section 15 extracts, for example, a relocation schedule involving relocation time close to the present time from among the optimal relocation schedules for respective storage batteries determined in relocation determination section 14 , and lists these information items on the display or on a printout. Based on these information items, an operator sets the schedule for relocation exchange for storage batteries in the plurality of vehicle 100 , the plurality of house 200 , the plurality of building 300 , the plurality of factory 400 , and collected-battery warehouse 500 , and advances a procedure of relocation of the storage batteries. That is, the operator and a worker, for example, report to a contractor, an exchange of a storage battery, and then perform exchange maintenance of a storage battery on the basis of the schedule for a relocation exchange. Configuration of Facility Using or Keeping Storage Battery [0049] Vehicle 100 includes storage battery B, charger 101 , battery control section 102 , in-vehicle communication section 103 , and socket 104 . Storage battery B supplies electric power to a running motor (not illustrated) of vehicle 100 to drive the vehicle. Socket 104 is connected to external cable 211 for the input of an external power source and transmission and reception of data. Charger 101 charges storage battery B with the external power source inputted from socket 104 . [0050] Battery control section 102 controls necessary electric power supplied to the running motor from storage battery B. Battery control section 102 measures and monitors, for example, the voltage, input and output currents, a temperature, a state of charge (SOC), and a deterioration state (SOH: State Of Health) of storage battery B, and transmits these information items to storage battery relocation assistance server 1 through in-vehicle communication section 103 . If cable 211 serving as a communication path is connected to socket 104 , in-vehicle communication section 103 performs data communication through cable 211 . Otherwise, in-vehicle communication section 103 is connected to network 600 through radio communication and performs data communication. [0051] Here, the state of charge (SOC) is the ratio of a residual capacity to a fully charged capacity, and the deterioration state (SOH: State Of Health) is a value representing a state of deterioration of a storage battery calculated from the internal resistance value of the storage battery. [0052] House 200 includes, for example, storage battery B, battery control section 201 , electric load 202 , and in-house communication section 203 . For example, storage battery B is charged with electric power from a commercial power source (also referred to as a common power source) in the time zone when an electricity price is low, and supplies electric power to electric load 202 in the time zone when the electricity price is high or when electricity is deficient. Electric load 202 is one of various kinds of electric appliances used in house 200 . Battery control section 201 measures and monitors, for example, the voltage, input and output currents, a temperature, a state of charge (SOC), and a state of health (SOH) of storage battery B, and transmits these information items to storage battery relocation assistance server 1 through in-house communication section 203 . In-house communication section 203 can be connected to network 600 to perform data communication. [0053] Each of building 300 and factory 400 also includes storage battery B, a battery control section, an electric load, and a communication section similarly to house 200 . [0054] When relocation use (also referred to as reuse) of storage batteries B is performed between the facilities which are vehicle 100 , house 200 , building 300 , and factory 400 , collected-battery warehouse 500 is a facility for keeping storage batteries B temporarily collected from any of the facilities. [0055] Collected-battery warehouse 500 includes collected storage battery B, battery management section 501 , and communication section 502 . [0056] Battery management section 501 controls storage battery B so as to be maintained in an appropriate state of charge, or control storage battery B so as to appropriately charge and discharge, in order to delay the progression degree of deterioration of storage battery B. Battery control section 501 measures the voltage, input and output currents, a temperature, a state of charge (SOC), and a state of health (SOH) of storage battery B, and transmits the measurement result to storage battery relocation assistance server 1 through communication section 502 . In-Use Battery Information [0057] FIG. 2 is a data table illustrating an example content of the in-use battery information stored in in-use battery information storing section 21 . [0058] In-use battery information storing section 21 stores a plurality of respective information items representing states of a plurality of storage batteries used in the plurality of facilities. To these information items, the information collected by in-use battery state collection section 11 is sequentially added. [0059] The in-use battery information stored in in-use battery information storing section 21 includes, for example, a model number, a present use place, the history of past use places, an initial capacity, a voltage log, a current log, a temperature log, a state of charge (SOC), a state of health (SOH), and charge/discharge allowable electric power (also referred to as an SOP: State Of Power (prediction electric power ability)). These information items are independently stored for all the registered storage batteries. Information on the voltage log, the current log, and the temperature log is stored as the series of data representing the voltage, current, and a temperature at a plurality of time points (ti), respectively. Information on the state of charge, the state of health, and charge/discharge allowable electric power is also stored as the series of data representing the respective values at a plurality of time points. [0060] Here, the charge/discharge allowable electric power (SOP) represents the maximum charge electric power and the maximum electric discharge electric power estimated from, for example, the voltage and the internal resistance of the storage battery. [0061] In-use battery state collection section 11 collects, from each facility, respective information items on the voltage log, the current log, the temperature log, the state of charge (SOC), the deterioration state (SOH), and the charge/discharge allowable electric power (SOP) among the items in the data table of FIG. 2 . In-use battery state collection section 11 then adds the collected information items to the in-use battery information items and stores the resultant information items. [0062] Collected-battery information storing section 26 also stores respective collected-battery information items including the items in the data table of FIG. 2 . Collected-battery state collection section 17 collects, from collected-battery warehouse 500 , respective information items on the voltage log, the current log, the temperature log, the state of charge (SOC), the deterioration state (SOH), and the charge/discharge allowable electric power (SOP). Collected-battery state collection section 17 then adds the collected information items to the collected-battery information items and stores the resultant information items in collected-battery information storing section 26 . Deterioration Prediction Information [0063] FIG. 3 is a data table illustrating an example of the deterioration prediction information stored in in-use battery deterioration prediction information storing section 22 . [0064] As illustrated in FIG. 3 , in-use battery deterioration prediction information storing section 22 stores a plurality of pieces of curvilinear data of deterioration states predicted according to various relocation models for each storage battery. [0065] The relocation model is a model representing at which time and to which facility a target storage battery is relocated. The relocation model will be described below in detail. As illustrated in FIGS. 9A to 9D, 9M and 9Q , various relocation models are set so as to include various relocation patterns possible for relocation of storage batteries in reality. [0066] The curvilinear data of deterioration states will be described below in detail. As illustrated in FIG. 10 , the curvilinear data is data representing a time variation in a deterioration state (referred to as SOH or “the residual capacity of a battery”). Use-Destination-Information [0067] FIG. 4 is a data table illustrating an example of the use-destination-information stored in use-destination-information storing section 23 . [0068] The use-destination-information includes, as information representing each facility, use destination data for identifying the facility, contractor data for identifying a contractor, and use destination category data for representing the category (for example, a vehicle, a house, a building, and a factory) of the facility, for example. The use-destination-information includes, as requirement information to the storage battery, information on contract electric power demand representing the maximum electric power which can be supplied from the storage battery, information on a contract battery capacity representing the minimum capacity of the storage battery, and information on an installation space for installing the storage battery, for example. [0069] Use-destination-information storing section 23 stores the above-described use-destination-information for all facilities receiving service of the supply of the storage batteries. [0070] When a contractor is added, information representing the facility of the contractor is inputted from input section 13 , and use-destination-information concerning the new contractor is added to use-destination-information storing section 23 . Relationship between Relocation Use and Deterioration Curve [0071] Here, the action and the advantageous effects of the relocated and used storage battery will be explained. [0072] FIG. 5 is a graph illustrating a time variation in the discharge capacity of the same storage battery charged and discharged repeatedly with a predetermined current amount. [0073] Respective three graph lines in FIG. 5 indicate the cases of high, middle, and low charge/discharge currents. [0074] As illustrated in the graph of FIG. 5 , the storage battery deteriorates and gradually decreases the discharge capacity (also referred to as a battery capacity) by repeating charge and discharge. The magnitude of a charge/discharge current for the storage battery, i.e., the severity of use of the storage battery also varies the rate of deteriorating the storage battery. For example, a higher charge/discharge current increases the rate of the deterioration, and a lower charge/discharge current decreases the rate of the deterioration. [0075] The graph line for the high charge/discharge current in FIG. 5 indicates an example case used for a vehicle. Storage battery B of vehicle 100 outputs a large current in the case of running, and rapidly charges in the case of charging. Therefore, the use conditions for the storage battery in vehicle 100 are very severe in comparison with the other facilities. Moreover, since vehicle 100 is required to have a high storage battery performance, the storage battery performance reaches the lower limit of the required performance of vehicle 100 at a stage at which the deterioration degree of the storage battery does not progress so much. [0076] The graph line for the middle charge/discharge current in FIG. 5 indicates an example case used for a house. Storage battery B in house 200 or building 300 charges and discharges relatively moderately. Furthermore, in house 200 or building 300 , the installation space for storage battery B is large in comparison with vehicle 100 , and many storage batteries can be used in parallel. Therefore, in house 200 or building 300 , the use conditions required for storage battery B are moderate in comparison with vehicle 100 . Moreover, since the use conditions are moderate, the storage battery performance required for house 200 or building 300 is low in comparison with that for vehicle 100 . [0077] The graph line for the low charge/discharge current in FIG. 5 indicates an example case used for a factory. In factory 400 , storage battery B charges and discharges in a further planned and stable manner. Moreover, in factory 400 , the installation space for storage battery B is further large in comparison with house 200 and building 300 , and an enormous number of storage batteries can be used in parallel. Therefore, the use conditions for storage battery B in factory 400 are moderate in comparison with the use conditions for house 200 and building 300 . Moreover, since the use conditions are moderate, the storage battery performance required for factory 400 is low in comparison with those for house 200 and building 300 . [0078] Therefore, as illustrated in FIG. 5 in many cases, the progression degree of deterioration is large in the storage battery used in vehicle 100 , and decreases in the storage batteries used in house 200 (or building 300 ) and factory 400 in this order. [0079] Even if vehicles 100 are of the same type, respective vehicles 100 involve different progression degrees of deterioration since, for example, users use vehicles 100 at different frequencies. In the other facilities, the progression degrees of deterioration also differ in the respective facilities similarly. [0080] Moreover, as illustrated in FIGS. 6A to 6C , the storage battery performance required for each application is the highest in vehicle 100 , and decreases in the order of house 200 (or building 300 ) and factory 400 . [0081] FIGS. 6A to 6C are graphs illustrating changes in deterioration curves in the case of relocation use of the storage battery. FIGS. 6A to 6C illustrate deterioration curves of storage batteries when a storage battery used for a certain period in a vehicle continues being used in the vehicle and when the storage battery used for the certain period is relocated to and used in a house or a factory, as an example. [0082] As illustrated in FIGS. 6A to 6C , the deterioration curve of a storage battery variously changes depending on to which facility the storage battery is relocated for use and depending on when the storage battery is relocated. Moreover, assuming that the time point of the storage battery performance reaching the lower limit of the performance required for each facility is defined as a storage battery life, as can be seen from comparison in FIGS. 6A to 6C , the relocation use of a storage battery can lead to a longer storage battery life of the storage battery. Configuration of Storage Battery [0083] FIG. 7 is a configuration diagram illustrating the details of storage battery B. [0084] Storage battery B as an object to be provided in a system of the present embodiment is composed of, for example, a lithium ion secondary battery. Storage battery B is provided by being packaged in a form of battery pack BP which can readily be mounted on each facility. Moreover, battery pack BP includes a plurality of battery modules BM bundled in order to provide predetermined output and capacity. Moreover, each battery module BM has a plurality of battery cells BC mounted therein. [0085] The collection and management of the battery information and the relocation use of the storage battery described above can be performed in units of battery packs BP, and also in units of battery modules BM or in units of battery cells BC. Deterioration Prediction Process on Storage Battery [0086] Next, a storage battery deterioration prediction process performed by in-use battery deterioration prediction section 12 will be explained. [0087] FIG. 8 is a flow chart illustrating the procedure of the storage battery deterioration prediction process. FIG. 9 is an explanatory diagram illustrating the various relocation models subject to deterioration prediction. FIGS. 10A to 10C are graphs illustrating the outline of the deterioration prediction curves of the storage battery in one relocation model. FIGS. 11A to 11C are graphs illustrating the outline of the deterioration prediction curves of the storage battery in another relocation model. [0088] For example, at a time when an execution instruction is inputted from an operator, or at predetermined time intervals, in-use battery deterioration prediction section 12 starts this storage battery deterioration prediction process. If the process starts, in-use battery deterioration prediction section 12 first reads in-use battery information from the in-use battery information storing section in step S 11 . [0089] Next, in step S 12 , in-use battery deterioration prediction section 12 sequentially selectively sets one relocation model for relocating a storage battery in the plurality of facilities from among the various relocation models. [0090] As illustrated in FIGS. 9A to 9D, 9M and 9Q , the various relocation models include a plurality of relocation patterns in which a storage battery is first used for vehicle 100 having severe use conditions and is then relocated to house 200 , building 300 , or factory 400 in order of the gradually loosened use conditions. As illustrated in FIGS. 9B to 9D , the various relocation models also include relocation patterns involving the skip of one or more of house 200 , building 300 , and factory 400 . [0091] Moreover, the various relocation models also include patterns based on changing storage battery relocation time. For example, the relocation models in FIGS. 9A to 9M have patterns in which a storage battery is relocated when the storage battery performance reaches the lower limit of the required performance for the facility using the storage battery. On the other hand, the relocation model in FIG. 9Q has a pattern in which a storage battery is relocated a little earlier (for example, a storage battery is relocated when the storage battery performance reaches a higher level by a predetermined amount than the lower limit of the required performance). [0092] Moreover, as illustrated in FIGS. 9D and 9M , the various relocation models also include patterns in which a relocation destination is set to another house 200 , another building 300 , or another factory 400 in the same category. Even in a facility in the same category (for example, house), a storage battery is severely utilized in some place and less severely utilized in another place, and the progression degree of deterioration is not necessarily the same. In consideration of this, the relocation model in FIG. 9M involves relocation destinations changed independently. [0093] In the case of an enormous number of facilities, if relocation models for relocating storage batteries are prepared for all the facilities, the number of relocation models increases significantly. Therefore, in the case of an enormous number of facilities, in the same facility category, a facility model may be prepared so as to have a standard progression degree of deterioration, a plurality of facility models may be prepared so as to have progression degrees of deterioration shifted from the standard degree at a plurality of levels, and these facility models may be combined to thereby prepare relocation models. [0094] Next, in step S 13 , in-use battery deterioration prediction section 12 predicts deterioration of the storage battery according to the relocation model set in step S 12 . For example, the graphs in FIGS. 10A to 10C illustrate the case of a relocation model in which a storage battery used in vehicle 100 is used down to the lower limit of the required performance in each facility and is sequentially relocated to house 200 and then factory 400 . [0095] In this case, in-use battery deterioration prediction section 12 predicts the deterioration prediction curve in vehicle 100 in FIG. 10A , for example, from the time transition data of the deterioration state (SOH) in the in-use battery information. Alternatively, in-use battery deterioration prediction section 12 can calculate a deterioration prediction curve from the data of the voltage log, the current log, and the temperature log in the in-use battery information, assuming that the same use situation continues. [0096] In-use battery deterioration prediction section 12 also calculates the deterioration prediction curve in house 200 in FIG. 10B , on the basis of the in-use battery information on another storage battery used in house 200 . That is, a deterioration prediction curve is calculated from the data of the time transition data of the deterioration state (SOH) or the voltage log, the current log, and the temperature log included in the in-use battery information, assuming that the storage battery is used in the same situation. [0097] Furthermore, in-use battery deterioration prediction section 12 similarly calculates the deterioration prediction curve of factory 400 in FIG. 10C , on the basis of the in-use battery information on another storage battery used in factory 400 . [0098] Next, another example of a deterioration prediction step will be explained. The graphs of FIGS. 11A to 11C illustrate the case of a relocation model for sequentially relocating a storage battery presently used in vehicle 100 to house 200 and factory 400 in a stage involving a higher level by 10% than the lower limit of the required performance in each facility. [0099] In this relocation model, in-use battery deterioration prediction section 12 calculates a deterioration prediction curve by setting the relocation time for a storage battery to the time when the storage battery performance reaches a higher value by a predetermined ratio than the lower limit of the required performance of each facility. In-use battery deterioration prediction section 12 also summarizes and calculates prediction of the progression degree of deterioration in each facility on the basis of the in-use battery information also in this relocation model similarly to the case of the relocation model in FIG. 10 . [0100] In-use battery deterioration prediction section 12 may also read the use-destination-information from use-destination-information storing section 23 to acquire information on the storage battery required performance in each facility. [0101] Through such deterioration prediction, in-use battery deterioration prediction section 12 obtains the deterioration prediction curve of the storage battery for one relocation model, as illustrated in FIGS. 10A to 10C or 11A to 11C . [0102] Next, in step S 14 , in-use battery deterioration prediction section 12 accumulates the prediction result data representing the deterioration prediction curve obtained in step S 13 , into in-use battery deterioration prediction information storing section 22 . [0103] Through a process loop of steps S 12 to S 15 , in-use battery deterioration prediction section 12 then repeats the deterioration prediction and accumulation of the prediction result data for all the relocation patterns. Through a process loop of steps S 11 to S 16 , in-use battery deterioration prediction section 12 also repeats the deterioration prediction and accumulation of the prediction result data for all the storage batteries. [0104] Through such a storage battery deterioration prediction process, as illustrated in FIG. 3 , in-use battery deterioration prediction information storing section 22 accumulates therein the data of the deterioration curve in the case of the relocation use in the various relocation models for each storage battery. Deterioration Prediction of Collected Battery [0105] Collected-battery deterioration prediction section 16 predicts deterioration of the plurality of storage batteries B that would occur if they are continued to be kept in the collected-battery warehouse, and stores the data of the predicted deterioration curve in collected-battery deterioration prediction information storing section 25 . [0106] This deterioration curve can be predicted and calculated from the time transition data of the deterioration state (SOH) or the data of the voltage log, the current log, and the temperature log stored in collected-battery information storing section 26 , assuming that the deterioration progresses in the same situation. [0107] Additionally, collected-battery deterioration prediction section 16 may also predict deterioration of a collected battery used by relocation, for example, to the house, the building, or the factory similarly to in-use battery deterioration prediction section 12 , and may store the deterioration curve in collected-battery deterioration prediction information storing section 25 . Relocation Determination Process [0108] Next, a relocation determination process performed by relocation determination section 14 will be described. [0109] FIG. 12 is a flow chart illustrating a procedure of the relocation determination process. [0110] FIG. 13 is a table illustrating determination requirements for relocating a storage battery. [0111] Relocation determination section 14 starts this relocation determination process in response to an instruction from an operator or at predetermined time interval. If the process is started, relocation determination section 14 first reads, in step S 21 , the data of predicted deterioration curve (also referred to as “deterioration prediction information”) of each storage battery from in-use battery deterioration prediction information storing section 22 , unused-battery deterioration prediction information storing section 24 , and collected-battery deterioration prediction information storing section 25 . [0112] Next, in step S 22 , relocation determination section 14 reads use-destination-information from use-destination-information storing section 23 . [0113] Then, in step S 23 , relocation determination section 14 determines the combination of the optimal relocation time and relocation destination (referred to as “relocation schedule”) for each storage battery on the basis of the read data, by performing a calculation process (for example, optimization process) for comprehensively improving the sufficiency level of a plurality of predetermined determination requirements. [0114] As illustrated in FIG. 13 , the determination requirements for relocating storage batteries include, for example, a requirement of maintaining the contract electric power demand in each use destination, a requirement of maintaining the contract battery capacity in each use destination, and a requirement of setting relocation time in a way that makes the relocation time close to a time when the storage battery performance comes near the lower limit of the required performance in each facility. Moreover, the determination requirements include, for example, a requirement of decreasing the number of new storage batteries to be supplied, a requirement of reducing a variation in the deterioration degrees of storage batteries simultaneously used in each facility, and a requirement of decreasing the reserved quantity of collected batteries. Moreover, the determination requirements include a requirement of increasing the usage rate of the installation space for storage batteries in each facility. [0115] The respective determination requirements are assigned with weighting factors λ 1 , λ 2 , . . . In step S 23 , relocation determination section 14 performs a calculation process so as to better satisfy a requirement having a larger weighting factor, and determines the relocation schedule for each storage battery. [0116] Through such a relocation determination step, for example, when the storage battery of certain house 200 approaches the lower limit of the required performance, the optimal storage battery which can be relocated from vehicle 100 to this house 200 is extracted to display this information on the relocation schedule. Similarly, when the storage battery of certain factory 400 approaches the lower limit of the required performance, the optimal storage battery which can be relocated from the plurality of vehicles 100 , houses 200 , or buildings 300 to this factory 400 is extracted to display this information on the relocation schedule. Moreover, when abnormality or a sign of failure is found in several storage batteries in a certain facility, information representing that the several storage batteries need to be replaced is displayed on the relocation schedule. [0117] Moreover, through the above-mentioned relocation determination step, the calculation process for comprehensively improving the sufficiency level of each determination requirement calculates a relocation schedule for storage batteries, the relocation schedule surely satisfying a requirement of maintaining the contract electric power demand in each use destination and a requirement of maintaining the contract battery capacity in each use destination. Moreover, the relocation schedule for each storage battery is calculated to set relocation time in a way that makes the relocation time as close as possible to a time when a storage battery comes near the lower limit of the required performance in each facility and so as to minimize the number of new storage batteries to be supplied. Moreover, the relocation schedule is calculated so as to minimize a variation in the deterioration degrees of storage batteries simultaneously used in each facility and so as to minimize the reserved quantity of collected batteries. Moreover, the relocation schedule is calculated so as to relocate many progressively deteriorated storage batteries to a facility having a large installation space to increase the usage rate of the large installation space. The relocation schedule is calculated according to other determination requirements that are set variously. [0118] Next, in step S 24 , relocation determination section 14 distinguishes a relocation schedule involving relocation time close to the present time (for example, within one month from the present time) from among the determined relocation schedules. Then, if relocation determination section 14 finds a relocation schedule close to the present time, relocation determination section 14 outputs information on the relocation schedule to reporting section 15 , in step S 25 . Thereby, the information on the relocation schedule is reported from reporting section 15 to an operator. [0119] Through such a relocation determination process, the optimized relocation schedule, which can better satisfy the determination requirements for relocation, for the storage battery is determined to display information on this relocation schedule for an operator. Based on the information on this relocation schedule, an operator sets the schedule for relocation exchange for storage batteries in the plurality of vehicle 100 , the plurality of house 200 , the plurality of building 300 , the plurality of factories 400 , and collected-battery warehouse 500 in reality, and can advance a procedure of relocation of the storage batteries. That is, the operator and a worker, for example, report an exchange of a storage battery and perform exchange maintenance of a storage battery for a contractor according to the schedule for a relocation exchange. Variation of Relocation Use of Storage Battery [0120] FIGS. 14A to 16 are explanatory diagrams of an example of repacking for relocating a storage battery. [0121] As illustrated in FIGS. 14A and 14B , instead of relocation of a storage battery, battery pack BP 1 , without modification, the storage battery may be relocated after repacking battery pack BP 1 into other battery packs BP 2 and BP 3 according to conditions of a relocation destination or the battery state in battery pack BP 1 . Alternatively, a storage battery may be relocated in units of battery modules BM 1 . [0122] Alternatively, as illustrated in FIG. 15 , a storage battery may be relocated after such repacking that the deterioration degrees of a plurality of battery modules BMa and BMb in battery packs BP 2 and BP 3 are uniform. Then, battery packs BP 2 a and BP 3 a repacked so as to have uniform deterioration degrees may also be relocated. [0123] Alternatively, as illustrated in FIG. 16 , when only one or more battery cells BC 1 in battery module BM 1 have deteriorated significantly, a storage battery may be relocated after replacing this battery cell BC 1 with battery cell BC 2 deteriorated in a similar degree to the other cells. Then, battery module BM 1 a partially replaced may be relocated. [0124] In the above-described relocation determination process, relocation determination section 14 can also determine a relocation schedule in units of battery modules BM or in units of battery cells BC to thereby display information on combination for repacking battery packs and information on combination for uniforming non-uniform deterioration degrees. Advantageous Effects of Embodiment [0125] As described above, according to storage battery relocation assistance server 1 and the storage battery recycle system in this embodiment, the in-use battery information representing the states of the plurality of storage batteries used in the plurality of facilities is collected in storage battery relocation assistance server 1 . Furthermore, in-use battery deterioration prediction section 12 in storage battery relocation assistance server 1 predicts deterioration of storage batteries in the case of relocating the storage batteries in the plurality of facilities, on the basis of these information items. Therefore, this deterioration prediction result can assist determination of the optimal relocation time and relocation destination of a storage battery. [0126] According to storage battery relocation assistance server 1 in this embodiment, relocation determination section 14 determines the combination of the optimal relocation time and relocation destination for each storage battery, on the basis of the deterioration prediction result in the case of relocating each storage battery among the plurality of facilities and the use-destination-information. Storage battery relocation assistance server 1 then outputs information on the relocation schedule of the determination result to the exterior. Therefore, on the basis of the information on this relocation schedule, an operator or a worker can set the schedule for relocating storage batteries in reality among the plurality of facilities and can cause the plurality of storage batteries to be relocated and used in the plurality of facilities. This can contribute to a comprehensive cost reduction for the life cycle from manufacturing to recycling of a storage battery. [0127] The embodiment of the present invention has been described thus far. [0128] The above-described embodiment has been described in an example case where in-use battery state collection section 11 collects battery information through communication network 600 . However, the battery information may also be collected after a delay of one week to several months, instead of real-time collecting of the battery information. Therefore, for example, the battery information may be accumulated in the facility during a predetermined period, and in-use battery state collection section 11 may collect this battery information through a storage medium, such as a record disk, a memory card, or a USB (Universal Serial Bus) memory. Specifically, the storage medium having battery information written in the facility may be sent to the manager of storage battery relocation assistance server 1 , and the manager may read battery information from this storage medium to send the battery information to in-use battery state collection section 11 . [0129] The embodiment has been described above with an example which involves one kind of storage battery, i.e., a lithium ion secondary battery. However, storage battery relocation assistance server 1 may handle a plurality of kinds of storage batteries (for example, a lithium ion secondary battery and a nickel hydrogen secondary battery). Storage battery relocation assistance server 1 then performs a relocation schedule for relocating, to a facility using a first kind of storage battery, and using a second kind of storage battery. [0130] The embodiment has been described using specific examples for the contents of the in-use battery information, use-destination-information, and the determination requirement for relocation. However, the in-use battery information, the use-destination-information, and the determination requirement for relocation are not limited to the contents described in the embodiment. The relocation model which is set for predicting deterioration of a storage battery can also be modified appropriately by, for example, adding a relocation model having a collection period in midstream. [0131] The disclosure of Japanese Patent Application No. 2011-266774, filed on Dec. 6, 2011, including the specification, drawings and abstract, is incorporated herein by reference in its entirety. INDUSTRIAL APPLICABILITY [0132] The present invention can be utilized for the storage battery comprehensive management service for relocating and using a storage battery among the plurality of facilities. REFERENCE SIGNS LIST [0000] 1 Storage battery relocation assistance server 11 In-use battery state collection section 12 In-use battery deterioration prediction section 13 Input section 14 Relocation determination section 15 Reporting section 16 Collected-battery deterioration prediction section 17 Collected-battery state collection section 20 Storing section 21 In-use battery information storing section 22 In-use battery deterioration prediction information storing section 23 Use-destination-information storing section 24 Unused-battery deterioration prediction information storing section 25 Collected-battery deterioration prediction information storing section 26 Collected-battery information storing section 100 Vehicle 200 House 300 Building 400 Factory 500 Collected-battery warehouse 600 Network B Storage battery BP Battery pack BM Battery module BC Battery cell
The present invention serves to reduce the costs associated with the overall life cycle of storage batteries by performing support so that a plurality of batteries are transferred between and used at a plurality of facilities. This storage battery transfer support device comprises: a collection unit that collects battery information representing the status of each battery used at a plurality of facilities; a battery information storage unit that stores the battery information collected by the collection unit; and a deterioration prediction unit that, on the basis of the battery information stored in the battery information storage unit, predicts deterioration of storage batteries that have been transferred between and used at a plurality of facilities.
1
BACKGROUND TO THE INVENTION (a) Field of the Invention The present invention relates to flame-effect heating apparatus. In particular it relates to flame-effect heating apparatus which is adapted for connection to a domestic water heating system. (b) Description of the Prior Art It has long been thought desirable to combine the aesthetically appealing qualities of a burning solid fuel fire, with the convenience and efficiency of an electric heater. Over the years, so-called “flame-effect” systems have been incorporated into a wide range of electric heating appliances, such as radiant, convector and fan-assisted heaters. The flame-effect is often achieved by a combination of the reflection of light onto a screen, and the creation of a flickering effect by means of a spinner mounted above the light source. Alternatively, or additionally, moveable ribbons may be used to reflect light onto the screen. In use, the ribbons are blown by a fan, and the resultant random motion thus adds to the realism of the flame-effect. However, despite the widespread use of flame-effect systems in conventional electric heaters, until now no such system has been satisfactorily incorporated into a so-called “hydronic” heater. The term “hydronic” is used herein to refer to heating apparatus which heats air by causing it to flow over a heat exchanger, through which is passed a heated liquid. For the purposes of domestic heating, the liquid is normally water, with the heat exchanger being in liquid communication with a domestic water heating system. SUMMARY OF THE INVENTION The present invention provides flame-effect hydronic heating apparatus, which also incorporates improvements to existing flame simulation techniques. According to the present invention, there is provided heating apparatus comprising: a housing having walls which define an air duct extending through said housing; simulated fuel supported by the housing, external of the air duct; flame simulation means comprising at least one flame-effect generator disposed in the air duct, a light source supported by the housing to illuminate both said simulated fuel and said at least one flame-effect generator, a mirror supported by the housing so that light from said light source and reflected by said at least one flame-effect generator is incident thereon, a wall of said housing defining the air duct being formed as a viewing screen on which light reflected by said mirror falls, the viewing screen being positioned at a higher level than said simulated fuel; an electrically-driven fan disposed to cause air to flow through the air duct, so causing operation of said at least one flame-effect generator; and a heat exchanger disposed in said air duct so as to cause air passing thereover to be warmed. The term “flame-effect generator” as used herein includes any flexible material capable of reflecting or obstructing light so as to produce simulated flames on the screen. The flexible material may be in the form of one or more ribbons or strips of lightweight fabric, metallised foil or other suitable material. Such ribbons or strips may be tethered at their upper and/or lower ends. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 is a cross-sectional view of flame-effect hydronic heating apparatus according to the present invention; FIG. 2 shows the heating apparatus of FIG. 1, with a diagrammatic representation of airflow therethrough when the apparatus is in use; FIG. 3 shows a preferred embodiment of the heating apparatus of FIGS. 1 and 2, having its viewing screen hingedly mounted to enable access to the air duct; FIG. 4 shows a preferred embodiment of the heating apparatus of FIGS. 1 and 2, having its light source mounted on a removable portion of the housing to enable replacement of a light bulb; and FIG. 5 is a schematic diagram showing the connection of the heating apparatus to a domestic water heating system. DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the present invention, there is more than one flame-effect generator, each of which is formed from a piece of lightweight, flexible fabric having an upwardly-tapering profile so as generally to imitate the shape of a flame. The pieces of light weight flexible fabric preferably have a reflective finish, and advantageously are of silk. In order to facilitate the random movement of the flame-effect generators in the air duct, it is preferred that they be tethered at their lower ends only to a grille provided in the air duct above the electrically-driven fan. The upper ends are thus able to move freely in the air-stream. The grille prevents the generators from falling into the fan when said fan is switched off. For convenience, the flame effect generators may be removably attached to the grille, preferably by the provision of co-operating magnetic attachment means on both the generators and the grille. Alternatively a Velcro®-type hook and loop fastener arrangement may be used. The air duct preferably extends from an air inlet located at a lower front part of the housing, to an air outlet located at an upper front part of the housing, with a forward-facing wall of the housing forming part of the air duct and serving as the viewing screen. Preferably, a single electrically-driven fan is used both to cause operation of the flame-effect generators and to direct air over the heat exchanger. By contrast, conventional non-hydronic electric heaters incorporating similar flame-effect systems usually employ a first fan to operate the flame-effect generators and a second fan to pass air over the heating element. In preferred embodiments, the electrically-driven fan is disposed in the air duct adjacent to the air inlet, the heat exchanger is disposed adjacent to the air outlet, and the flame-effect generators are disposed therebetween. It is currently most preferred that the fan be disposed at the bottom of a flame-effect chamber defined within a substantially vertical portion of the air duct, the nozzle of the fan being directed upwards into said chamber. When the apparatus is in use, air is drawn in through the inlet by the fan, turned through substantially 90°, and blown up through the flame-effect chamber and over the heat exchanger, before exiting through the outlet. The heat exchanger preferably has connectors to permit the liquid communication thereof with a domestic water heating system, when installed. In preferred embodiments of the present invention, the apparatus is provided with control means, arranged automatically to switch on both the electrically-driven fan and the electrically-driven light source upon activation of the water heating system. Preferably, the control means comprises a thermostat, such that the fan and light source are activated when the water in the heating system is heated to a pre-selected temperature. It is currently preferred that this activation temperature should be substantially 47° C. The control means may desirably also permit the electrically-driven fan and the light source to be switched on independently of the temperature of water in the water heating system. In this way the present invention may be used to simulate the visual appearance of a burning solid fuel fire, even when no heating is required. In a most preferred embodiment of the present invention, the control means is adapted to operate the electrically-driven fan at two or more pre-selected speeds. Operating the fan at a higher speed, increases the flow of air over the heat exchanger, thus leading to an increase in the heat given out by the heating apparatus. Additionally, the flame-effect generators are caused to move faster, and the resultant reflections increase the flickering of the simulated flames. This creates the illusion that the increased heat output results from the intensified flame-effect, thus enhancing the realism of the flame-effect. In currently preferred embodiments of the present invention, the viewing screen has a forward-facing surface which is generally non-reflective and a rearwardly-directed surface which is generally diffusing. In order that the flame-effect generators may easily be removed for cleaning, it is preferred that the viewing screen is hingedly and/or removably mounted on the housing, thus enabling access to the air duct. Similarly, in a preferred embodiment, the light source comprises a fitting for a light bulb, said fitting being mounted on a removable portion of the housing, to enable replacement of the light bulb. A particular embodiment of the heating apparatus of this invention will now be described with reference to accompanying FIGS. 1 to 5 . Referring initially to FIG. 1, there is shown heating apparatus, generally indicated 10 , having a housing 11 , within which is defined an air duct 12 . The air duct 12 extends from an inlet 13 , located at a lower front part of the housing 11 , to an air outlet 14 , located at an upper front part of the housing 11 . A cavity 15 is defined externally of the air duct 12 , by a transparent or translucent portion 16 of the housing 11 . A light source 17 located within the cavity 15 , is disposed so as to illuminate both simulated fuel 18 , and also flame-effect generators 19 , located in the air duct 12 . The flame-effect generators 19 are formed from pieces of silk having a flame-shaped profile. The simulated fuel 18 is supported by the transparent or translucent portion 16 of the housing 11 . A mirror 21 provided on a rear wall of the air duct 12 , is disposed to reflect light from the light source 17 and the flame-effect generators 19 , onto a viewing screen 22 which, together with a rear wall of the housing 11 , defines a flame-effect chamber 23 in the air duct 12 . An electrically-driven fan 24 having a nozzle 25 is located in the air duct 12 , and is arranged such that said nozzle 25 is directed upwards towards the flame-effect chamber 23 . Mounted immediately above the fan 24 is a grille 26 , which extends across the air duct 12 , and has a peg 27 upstanding therefrom. The flame-effect generators 19 have a lower end 28 which is removably attached to the upstanding peg 27 , by co-operating magnetic attachment means provided thereon. Alternatively, the upstanding peg 27 and the lower end 28 of the flame-effect generators 19 may each be provided with co-operating hook and loop fasteners, such as those sold under the trade mark Velcro®. Extending across an upper portion of the flame-effect chamber 23 of the air duct 12 is a heat exchanger 29 . The heat exchanger 29 is provided with an air bleeding valve 32 and thermostatic control means 33 , which control means are operatively linked with the fan 24 , the light source 17 , and a control switch 34 located externally on the housing 11 . The heat exchanger 29 is also provided with connectors 31 to permit the linking thereof with a domestic water heating system 46 , as shown in FIG. 5 . Extending across an upper portion of the flame-effect chamber 23 of the air duct 12 is a heat exchanger 29 . The heat exchanger 29 is provided with an air bleeding valve 32 and thermostatic control means 33 , which control means are operatively linked with the fan 24 , the light source 17 , and a control switch 34 located externally on the housing 11 . The heat exchanger 29 is also provided with connectors 31 to permit the linking thereof with a domestic water heating system 46 , as shown in FIG. 5 . During use of the heating apparatus, as shown in FIG. 2, when the temperature of the water in the heat exchanger 29 reaches a pre-selected temperature, the fan 24 and the light source 17 are switched on automatically by the thermostatic control means 33 . The fan 24 draws air from the ambient into the air duct 12 , through the air inlet 13 located at a lower front part of the housing 11 . A decorative facia 35 may be mounted on the front part of the housing 11 . As the air is drawn through the electrically-driven fan 24 , the direction of the air flow (indicated by the arrows) is turned through substantially 90°, and the air is then blown upwards through the flame-effect chamber 23 , causing motion of the flame-effect generators 19 . At the same time, the light source 17 illuminates the flame-effect generators 19 and the simulated fuel 18 through the transparent or translucent portion 16 of the housing 11 . Light from the light source 17 and the flame-effect generators 19 is reflected by the mirror 21 onto the viewing screen 22 which is light-diffusing at its rear surface 47 , and non-reflective at its forward facing surface 48 . An observer, generally indicated at 36 , therefore sees a diffuse image of simulated flames dancing randomly on a portion of the viewing screen 22 immediately above the simulated fuel 18 . The fan 24 drives the air past the flame-effect generators 19 , and on to the heat exchanger 29 . The air is heated as it passes over the heat exchanger 29 . The direction of the air flow is then turned again through substantially 35° by a sloping cowl 37 at the end of the air duct 12 adjacent to the outlet 14 . The heated air is then returned to the ambient through the outlet 14 , immediately above the simulated flames on the viewing screen 22 , and the simulated fuel 18 . The observer 36 thus experiences the illusion that the heat is emanating from the simulated flames on the viewing screen 22 . Alternatively, the control switch 34 may be used to override the thermostatic control means 33 such that the heating apparatus 10 operates in “flame-effect only” mode. In this mode of operation, the electrically-driven fan 24 and the light source 17 are switched on, thus providing the simulated flames on the viewing screen 22 , but no heating of air occurs due to inactivity of the water heating system. The control switch 34 may also be used when the heating apparatus 10 is operating in its normal heating mode, to vary the speed of rotation of the electrically-driven fan 24 . By causing the fan 24 to operate at a higher speed, the flow of air over the flame-effect generators 19 and the heat exchanger 29 is increased. Consequently, the simulated flames on the viewing screen 22 appear to move quicker, whilst a greater amount of heat is emitted through the outlet 14 . For the observer 36 , this adds to the realism of the illusion that the heat emanates from the simulated flames. Referring now to FIG. 3, it will be seen that the viewing screen 22 is mounted by a hinge 38 at its lower end, to the transparent or translucent portion 16 of the housing 11 . The upper end of the viewing screen 22 is releasably attached to a portion of the housing 11 in front of the heat exchanger 29 , by means of a catch 39 . The screen 22 can thus be detached from the housing 11 at its upper end by means of the catch 39 , and hinged forwards about hinge 38 , in order that access may be gained to the flame-effect chamber 23 . The flame-effect generators 19 may thus be removed by detaching the lower end 28 thereof from the upstanding peg 27 . Referring now to FIG. 4, in this embodiment of heating apparatus 10 , the light source 17 comprises a light bulb 41 , and a fitting 42 for said light bulb 41 . The fitting 42 is mounted on a removable portion 43 of the housing 11 . The front of this removable portion 43 forms part of the decorative facia 35 , and has a handle 44 . The removable portion 43 is normally held in place on the main part of the housing 11 by a retaining tab 45 which engages with a complementary slot (not shown) in the housing 11 . The light source 17 is thus normally held in place in the cavity 15 . When the light bulb 41 is to be changed, the removable portion 43 may be withdrawn from the main part of the housing 11 by pulling handle 44 forwards and upwards, until the removable portion 43 is clear of the housing 11 .
Flame-effect heating apparatus comprises a housing with walls defining an air duct extending therethrough. Simulated fuel is supported by the housing, externally of the duct, and at least one flame-effect generator is disposed in the duct. A light source is provided in the housing to illuminate both the simulated fuel and the flame-effect generator. A mirror is supported by the housing so that light reflected by the flame-effect generator is incident thereon. A wall of the housing which defines the air duct, is formed as a viewing screen on which light reflected by the mirror falls, the viewing screen being positioned higher than the simulated fuel. An electric fan causes air to flow through the air duct, so causing operation of the flame-effect generator, and a heat exchanger disposed in the duct warms air passing thereover.
5
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from Provisional Patent Application No. 60/588,460, filed Jul. 16, 2004. TECHNICAL FIELD OF THE INVENTION [0002] The technical field of the invention is in the area of manufacture of topical ingredients for skin and wound care. More especially in the processing and formulation of ingredients developed from natural products, which possess anti-irritant and/or free radical scavenging antioxidant properties. BACKGROUND OF THE INVENTION [0003] Among the agents recently proposed for minimizing skin irritation due to skin irritants are fibers (Creton, I., 2002. U.S. Patent Appl., 20020182238A1), and an immune suppressant such as a composition that blocks CD1d activation (Wilson, S. B., 2002. U.S. Patent Appl., 20020165170A1), discloses a method that blocks antigen presentation by skin located immune cells. Lacharriere et al., have proposed the use of a histamine antagonist and or a TNF-alpha antagonist (Lacharriere, O. De; et al., 2001 in U.S. Appl., No.: 20010022978A1). [0004] Historically, plants have been an important source of both new pharmaceuticals and new cosmetic ingredients. Even today plants have yield more new medicinal compounds and cosmetic ingredients than the chemical synthesis approaches exemplified by the recent reliance on combinatorial chemistry methods (C&EN, Oct. 13, 2003). [0005] The search for novel natural products from plants has led to a worldwide search for exotic plants in tropical rainforests of the Amazon and to the ocean depths. This has produced an array of new plant oils that fill the catalogs of commercial cosmetic ingredient suppliers, and to the harvesting of bacteria that inhabit temperature extremes for the purposes of isolating their heat stable enzymes. Yet, it must be noted, that the screening of higher plants for their useful drugs and cosmetic active ingredients has barely scratched the surface of the more than 250,000 species of flowering plants (Angiosperms), and very few of the 50,000 species of monocots (grasses and ornamentals) relatives to the 200,000 species of dicot herbs, shrubs, trees, and ornamentals). Below the flowering plant, aside from a few hallucinogenic mushrooms, and algal plants and bacteria that produce abundance polysaccharide gums, the realm of other plant phyla has been totally neglected. Aside from the lethal phytotoxins from red tides caused by unicellular Dinoflagellates, none of the highly diverse unicellular plants algae have been screened for useful drugs and cosmetics. Thus, it fair to conclude that a systematic and rationale approach to this task has yet to be formulated. [0006] The inventor has taken a different approach to the search for novel botanicals, i.e., plants with medicinal or cosmetic value. This approach narrows the search to plants that grow in the wild, and are cultivated primarily as a foodstuff but for which there is no present commercial medicinal or cosmetic uses. This has led to the discovery of many novel sources of plant derived anti-oxidants some of which are also anti-irritants [0007] A truly effective anti-irritant strategy seeks to modulate checkpoints in the irritant signal cascade. Earlier, Wille & Kydonieus (2000) reviewed the scientific and patent literature on anti-irritants. The aim of which was to find new agents useful in prevention and treatment of contact irritant due to topical cosmetic, dermatological and transdermal drugs. In a series of patents (Wille, U.S. Pat. No. 6,670,395, 2003; Wille, U.S. Pat. No. 5,716,987, 1998; Wille and Kydonieus, U.S. Pat. No. 5,843,979, 1998; Wille, Kydonieus and Castellan, U.S. Pat. No. 5,618,557, 1997; Wille and Kydonieus, U.S. Pat. No. 5,686,100, 1997; Wille and Kydonieus, U.S. Pat. No. 5,912,010, 1999; Wille, Kydonieus and Castellana, WO Pat. No. 9,718,782, 1997; Wille and Kydonieus, European Pat. No. 5,612,525, 1994; and in reports (Kalish R, Wood J, Wille J, and Kydonieus A, 1995; Wille, J J., Kydonieus, A., and Kalish, R S., 1998; Wille, J J., Kydonieus, A., and Kalish, R S., 1999a; Wille, J J, Kydonieus, A F., and Murphy, G F., 1999b; Wille, J J., Kydonieus, A F, and Kalish, R S., 2000; Wille and Kydonius, 2001; Wille, Kydonieus and Castellana, WO Pat. No. 9,718,782, 1997), it was shown that ion channel modulators and mast cell degranulating agents were effect anti-irritants and counter-sensitizers. Ethacrynic acid (Edacrinn, Merck) was effective in preventing contact sensitization due to the delivery to mouse skin of four sensitizing drugs: Clonidine, Chlorpheniramine, Albuterol, and Nadolol. Ethacrynic acid, a potassium ion channel blocker, was also effective in preventing skin irritation due to the topical application to mouse of 2,4-dinitro-chlorobenzene, arachidonic acid, phorbol myristic acid, trans-retinoic acid, and lactic acid. The calcium ion channel blockers Nifedipine and Verapamil were effective in minimize contact sensitization in mouse skin due to topical application of the sensitizing and transdermally delivered drug, Nadolol. Phenoxyacetic acid and its alkyl derivatives, non-drug analogs of the diuretic, ethacrynic acid, were shown to prevent contact sensitization due to application to mouse skin of the sensitizing hair dye, para-phenylenediamine and to block skin irritation due a panel of known skin irritants, including anionic surfactants such as sodium lauryl sulfate. Finally, agents which induce mast cell degranulation such as cis-urocanic acid and capsaicin were reported to prevent contact sensitization in a mouse skin model. [0008] Natural products and plant extracts have been the focus of recent interest as emollients and anti-irritants. Castro J (1995) in U.S. Pat. No. 5,393,526 discloses Rosmarinic acid (5%), derived from Sage plant, was able to reduce by more than three-fold the irritating action of alpha-hydroxy acids (lactic and glycolic acids). Pretreatment, one-half hour prior to application of cosmetic formulation containing known skin irritants, by para-aminobenzoic acid and balsam of Peru with extracts the Cola nitida plant, have been disclosed in European Pat. No. Application 0,354,554A2 to prevent skin irritation. Oil from Yerba plants have also been claimed in World Pat. No. Application WO 9,114,441 to eliminate irritation and sensitization that accompanies topical, tranmucosal and transdermal delivery of dihydroergotamine mesylate, acetominophen, oxymetazoline, diphenhydramine, nystatin, clindamycin, and para-aminobenzoic acid. Oils of chamomile, containing chamazulene isolated from yarrow, chamomile and wormwood, were disclosed in U.S. Pat. No. 4,908,213 to be good antipuretics when co-administered in transdermal Nicotine patches. [0009] Depletion of antioxidants is known to cause oxidative damage to human skin (Podda et al, 1998). As discussed above, flavonoids are known to be potent anti-oxidants. Topical replacement of skin anti-oxidants may help to alleviate damage due to ultraviolet radiation and ozone exposure. Flavonoids require stabilization against oxidation by addition of co-reductants such as Vitamin E (α-tocopherol) or Vitamin C (Ascorbic Acid). No mechanism exists to reduce oxidized Vitamin E since there is no Ascorbic acid in the upper layers of the epidermis (stratum corneum). Lazendorfer et al., (2002) in U.S. Pat. No. 6,423,747 discloses cosmetic and dermatological preparations with favonoids having anti-oxidant properties. Illustrative examples mention standard water-in-oil and oil-in-water formations without providing any evidence of their efficacy in these formulations. [0010] Of particular importance to the category of polyphenols and flavonoids is the demonstration (Wille, 2003) that the mechanism of action for many plant-derived anti-irritants is their inhibition of protein tyrosine kinases associated with growth factor receptor stimulated autocrine control of cell proliferation that is the hallmark of many useful skin products that cause skin irritation, i.e., retinoic acid. The use of flavonoids as anti-irritants are among the plant-derived anti-irritants that are readily formulated in the novel hydrophobic delivery system claimed in this patent. They include many plants and herbs are rich in flavonoids as well as flavonoids present in Spanish Honeybee pollen. For example, rutin, quercetin, myricetin, and trans-cinnamic acid; all were present at >350 mg/100 g. Recently, it was reported (Bonina et al, 2002), that Kaempferol is the major flavonoid derived from lyophilized extracts of the flowering buds of capers ( Capparis spinosa L). This material was shown to have both anti-oxidant and photo-protective effects in human skin. [0011] Antioxidants and free radical scavengers have been employed in many patented formulations for eliminating or minimizing irritation and contact sensitization reactions. Inhivbitors of the metabolites of the arachidonic acid cascade known to be involved in the irritant mechanism of skin have been claimed in European Pat. No. EP 0,314,528A1. Among the designated anti-irritants claimed were Vitamin E, BHT, para-tertiary butyl catechol, hydroquinone, benzoquinone, N,N-diethylhydroxyamine, and nordihydroguaiareic acid. [0012] Vitamin C (ascorbic acid), a water soluble antioxidant, was disclosed in U.S. Pat. No. 5,516,793 to be effective in decreasing skin irritation caused by topical application of such ingredients as: a-hydroxy acids, benzoyl peroxide, retinal, retinoic acid, quaternary ammonium lactates, and salicylic acid. Vitamin E (a-tocopherol) is disclosed in U.S. Pat. No. 5,545,407 to reduce skin irritation caused by actives in dermatological preparations containing benzoyl peroxide., and in U.S. Pat. No. 5,252,604 it was disclosed that topical α-tocopherol reduced skin irritation due to repeated doses of retinoic acid. Another antioxidant panthenol and its derivatives pantothenic acid, pantethine and pantetheine have been claimed as anti-irritants for formulations containing up to 20% benzoyl peroxide. [0013] The role of antioxidants in protecting the skin from harmful solar exposure, and photoaging is well known. In their book, “Oxidants and Antioxidant in Cutaneous Biology, Thiele and Elsner (2001) have assembled a comprehensive review of free radical chemistry in the skin and the antioxidant network of defense in the stratum corneum. Among the antioxidants discussed for protection of skin are Vitamins E and Vitamin C, green tea polyphenols, resveratol, curcumin, silymarin, ginger, and diallyl sulfide, all of which afford some protection against the development of skin cancer. In addition, the role of carotenoids (lycopenes, luein and α, and β-carotene) as dietary supplements in chemoprevention of cancer were reviewed. The protective effect of topical anti-oxidants against solar radiation result from e.g.: Vitamin E and Vitamin C. Other reported antioxidants that efficiently reduce photodamage include the thiol, N-acetylcysteine and α-lipoic acid, which may prevent oxidative stress in skin. In addition, plant-derived flavonoids (apigerneic genistein, catechin, epicatechin, a-glycosylrutin and silymarin) are polyphenols with good antioxidant activity. [0014] Vitamins C and E are routinely used as antioxidants to either stabilize cosmetic ingredients or more recently for their anti-aging free-radical scavenging properties. The most widely used botanical with accepted anti-irritant activity are is Aloe gel; and Witch Hazel (Hammelis Water) containing polymeric proanthocyanidins is by far the best documented case of a botanical anti-irritant. Other botanically-derived actives with potential anti-irritant activity are the catechins and polyphenols, e.g., green tea leaves, and grape seed oil extracts. Additional antioxidants derived from botanicals are Bisabolol, Epigallocatechine, Epigallocatechinegallate Rutin, Quercetin, Hesperidin, Diomine, Mangiferin, Mangostin, Cyanidin chloride, Astaxanthin, Xanthophylls, Lycopene, Reversatrol, Tetrahydrodiferuloylmethane, Rosmarinic acid, Hypericin, Ellagic acid, Chlorogenic acid, Oleoeuropein, Thiotic acid, Glutathione, and Andrographolide (Gupta, 2001). Few of these have been rigorously shown to have anti-irritant activity. Nevertheless, the prospects for broadening the base of plant derived anti-irritants is tremendous because only a small fraction of the over 250,000 known Angiosperm species has been explored. [0015] Here we claim the anti-irritant and antioxidant activity of several new plant-derived anti-irritants. They include a botanical anti-irritant isolated from corn plant tassels, dried lavender flowers, dried flowers of Hops plants, catkins of the Oak tree ( Quercus sp.), catkins of the Linen tree ( Tialia sp.), an extract from green tea leaves, green onion leaves; and extract from ripened Autumn Olive berries. These extracts have been incorporated into a novel carrier system (Wille, Novel Delivery Systems, 2004), especially designed to improve their cutaneous delivery. REFERENCES CITED U.S. PATENT DOCUMENTS [0000] Creton, I. U.S. Pat. No. Application No.: 20020182238A1. Fibers as anti-irritant agents. Korneyev, A. Y. U.S. Pat. No. 6,576,269 (Jun. 10, 2003). Treating open skin lesions using extract of sea buckthorn Perricone. U.S. Pat. No. 6,437,004 (Aug. 20, 2002). Treatment of skin damage using olive oil polyphenols. Wilson, S. B. U.S. Pat. No. Application No.: 20020165170A1. Method of attenuating reactions to skin irritants. Other Publications: J J Wille. Provisional Pat. No. Application No.: Novel Topical Delivery System for Plant Derived Anti-irritants (Jul. 4, 2003). J J. Wille. U.S.P.T.O Disclosure.—“Anti-Irritant Compounds Derived from Plant Extracts (Jun. 18, 2002). J J Wille. Novel Plant-Derived Anti-Irritants. Abstract in: J. Cosmet. Sci., 54: 106-107, 2003 J J Wille. Novel Topical Delivery System for Plant derived Hydrophobic Anti-Irritant Actives. Abstract presented at National Annual ACS Meeting NY, N.Y. (Sep. 17, 2003). J J Wille. Plant-derived anti-irritants. In Closing with John Wille. Cosmetics & Toiletries Vol. 118(8): 128, 2003. J J Wille. Thixogel: Novel Topical Delivery System for Hydrophobic Plant Actives. In: Personal Care Delivery Systems and Formulations Noyes Publication (in press). J J Wille. Cutaneous delivery of Antioxidant Botanicals. 23 rd Annual Congress of IFSCC Abstract (October 2004, in press). SUMMARY OF THE INVENTION [0027] There is disclosed here a method for screening, and then preparing anti-irritant botanical extracts for use in topical formulations in need thereof of a natural ingredient capable of preventing skin irritation when in combination with other active and inactive ingredients that have the potential to irritant skin. In addition, the natural botanical anti-irritants disclosed herein can be topically applied to skin in a formulation without an irritant for the purpose of preventing skin damage due to solar exposure or to oxidant type pollutants in the environment. [0028] Applicant has developed a novel means of screening for potential plant-derived anti-irritants following the strategy and testing assay was developed (USPTO Disclosure Document No. 514152, June 2002). Human epidermal keratinocytes cultured in a serum free culture medium require protein, two growth factors: insulin and epidermal growth factor (EGF) (Wille et al, 1984), by substituting retinyl acetate for EGF one can sustain continued proliferation under autocrine production of HB-EGF (HB-heparin binding), due to retinoid-inducible HB-EGF growth factor receptor (Wille, J. Invest. Dermatol., SID Abstract, 2002). Applicant has shown by use of a specific phosophotyrosine kinase (TRK) inhibitor, that retinoid inducible keratinocyte cell proliferation is dependent on TRK phosphorylation of the insulin growth factor receptor. In light of these discoveries, the inventor postulated that anti-irritants prevent epidermal hyperplasia by blocking retinoid inducible TRK activation of growth factor receptors. Therefore, the search for novel plant-derived anti-irritants involves screening plant extracts that inhibit retinoid-inducible autocrine regulation of human epidermal keratinocyte proliferation in a specially designed clonal growth assay. This assay has uncovered many potential plant-derived anti-irritants. [0029] The methods developed for preparing novel anti-irritant botanicals involves two steps, the sourcing and harvesting of plant materials and a novel processing methods. [0030] The aroma of herbs has been a source of botanicals with health, beauty and medical value since prehistoric times. Minoan archeological (2,500 BC) sites have revealed the use of botanical herbs that are still in use in the present day culinary arts of Crete and Greece (Greek book). As many as 70 different species were recorded by Theophrastus from Crete in Roman times including Dittany, a relative of the herb, Oregano. [0031] The aroma of plants may be used as a to guide to possible sources of new botanicals. In particular, certain phenoxy acids and benzoic acid derivatives have a peculiarly pungent smell. The inventor has previously disclosed that phenoxyacetic acid esters are in fact anti-irritants in U.S. Pat. No. 6,670,395(2003). Thus, the Inventor has relied primarily on his sense of smell to detect and source many novel anti-irritant plants. There include aromatic tassels of corn plants, and the male flowering structures of Oak ( Quercus genus), Linden ( Tilia genus) and Mimosa trees. All of which produce hydroalcoholic extracts enriched in anti-oxidants. [0032] Another source of botanicals with potential anti-oxidant and anti-irritant properties are edible plant fruiting bodies; in particular, the ripe red edible berries of Autumn Olive ( Eleagnus umbellate ) trees, and the orange berries of Sea Buckthorn ( Hippophae rhanmoides ), a closely related member of the Eleagnacae family. [0033] Hops ( Humulus lupulus ) grown in Europe since the 14 th Century as a bitter substance for brewing of beer was later discovered to contain lupulin, bitter resinous substances (lupulone, humulone) and essential oils in the strobiles from female plants. These lupulins are reputed to have drug like activities for relieving anxiety and inducing sleep. Modern-day cosmetics use this plant in a different form for its beta-hydroxy acids. It is our finding that this scented herb is highly enriched in anti-oxidants. [0034] Green tea leaves are rich in methyl xanthenes (caffeine, theophylline) and antioxidant polyphenols including catchins, and epigallocatechins. They have been the subject of much recent work on topical and dietary use to prevent cancer, and photodamage by exposure to ultraviolet light (UVA and UVB). Hydroalcoholic extracts of dried leaves are disclosed here as a rich source of anti-irritants. Likewise dried powders of cocoa bean plants, or commercial cocoa powder, and green tea leaves, contain both methyl xanthenes and polyphenols. Again, hydroalcoholic extracts of cocoa powder are disclosed here to be a rich source of anti-oxidants. The spice Cinnamon derived from the bark of Cinnamon trees has been reported to contain several polyphenolic compounds an active principle against diabetes (Ag Res Mag., April, 2004), a methyl hydroxychalcone polymer. Hydroalcoholic extracts of pure ground Cinnamon are disclosed here as potent anti-oxidants. [0035] In summary, this patent discloses methods for sourcing new anti-irritant botanicals and identification of anti-irritants among certain male flowering plant parts including corn plant tassels and several the male flowers of deciduous trees. In general, all plant extracts which are rich in anti-oxidants botanicals that also test positive in the in vitro assay for detection of inhibitors of retinoid-stimulated autocrine growth of keratinocytes. These methods have proved to be reliable indicators of anti-irritant activity of plant extracts. BRIEF DESCRIPTION OF THE DRAWINGS [0036] FIG. 1 is a plot of antioxidant activity for standard antioxidants (50 μg/ml): Vitamin E(▪), Ascorbic acid, Ascorbyl palmitate, and Quercetin dihydrate (X). [0037] FIG. 2 is a plot of antioxidant activity some tested botanicals: CTS (X), AOB (⋄), GTL (▪), GOL/RSC(●). [0038] FIG. 2A is a table of the relative antioxidant activity of the botanicals ploted in FIG. 2 . [0039] FIG. 3 is a photograph showing the effect of Quercetin dihydrate on autocrine growth of HaCat keratinocytes, cultured under retinoid-stimulated autocrine growth conditions. [0040] FIG. 4 is a photgraph showing the effect of Allin on autocrine growth of HaCat keratinocytes. [0041] FIG. 5 is a photograph showing the effect of extracts from corn tassels (Tasselin) and tomato paste lycopenes, versus Quercetin on autocrine growth of Ha Cat keratinocytes. [0042] FIG. 6 is a bar chart showing elevated skin hydration following 24-hour occlusion of a 5% GTL extract when co-administered in the carrier gel with a irritating concentration of Benzalkonium Chloride (0.5%). when co-administered in the carrier gel with a irritating concentration of Benzalkonium Chloride (0.5%). Effect of GTL on Skin Hydration: Vehicle (black bar); GTL (gray bar). [0043] FIG. 7 is a bar chart showing elevated skin hydration effect of AOB on Skin Hydration: Vehicle (while bar); AOB (black bar). [0044] FIG. 8 is a photograph of volar arm skin of human subject showing A) positive irritant control (0.5% BC only) versus B) 0.5% BC in combination with 5% Tasselin after 24 hours of occlusion. [0045] FIG. 9 is a table of Chromatographic data for corn tassel extract in methanol. [0046] FIG. 9A is a chromatograph showing the elution profile of corn tassel (Tasselin) extract versus authentic phenoxyacetic acid methyl ester. [0047] FIG. 10 is a UV-spectragraph of the corn tassel extract monitored by UV-scan of HPLC fractions. [0048] FIG. 11 is a table of antioxidant activity of solvent extracts of corn tassel pollen sacs. DETAILED DESCRIPTION OF THE INVENTION EXAMPLE 1 Preparation and Antioxidant Activity of Botanical Extracts [0000] Botanical Extraction: [0049] An equal volume of ice-cold 95% alcohol was added to 100 grams of either dried or wet weight (w/v) of minced plant material and the mixture blended at 23° C. for 2 minutes. The homogenate was clarified by low speed centrifugation at 5° C. and sterile filtered through (0.45 micron filter). All hydroalcoholic extracts so prepared were stored at 0-4° C. and protected from light until further use. Extract concentration was calculated using the percent weight of botanical material to the total volume of botanical weight plus extraction volume. This was 36% (w/v) for Autumn Olive berries (AOB), 5% f (w/v) for Corn Tassel Spikelets (CTS), 11% (w/v) for dried Green Tea Leaves (GTL), 37% (w/v) for Green Onion leaves (GOL), and 36% (w/v) for Red Swiss Chard (RSC, 36% wet weight). [0000] Anti-Oxidant Assay: [0050] Aliquots of botanical hydroalcoholic extracts were assayed for their antioxidant activity by the diphenylpicryl hydrazine (DPPH*) reagent method as described previously (Bonina et al, 2003). In order to standardize the activity of extracts, we defined for each extract an EC 50 value as the concentration of extract that lowers the zero time optical absorbance of DPPH at 515 nm by 50 percent measured after 30 minutes of incubation at 25° C. Antioxidant activity of extracts was calculated by multiplying its EC 50 value by a weighting factor representing the percent weight of the starting material in the extract. [0000] Antioxidant Activity of Botanicals. [0051] FIG. 1 shows a typical plot of antioxidant activity for several standard antioxidants as assayed by the DPPH* method. The molar activities of ascorbic acid, ascorbyl palmitate and vitamin E were calculated as 26 μM, 30 μM and 46 μM, respectively. Indole acetic acid, a weak free-radical scavenger, had a molar activity of 190 μM, Finally, a commercially purchased flavonoid, quercetin dihydrate; it had an intermediate molar activity of 86 μM. [0052] FIG. 2 shows the results of assaying by the DPPH method the antioxidant activity of AOB, GTL, GOL, RSC and CTS. Table 1 ( FIG. 2A ) presents these results as “Relative EC 50 Value”, i.e., normalized to percent weight of total volume of extract. [0053] We have assayed many other botanical hydroalcoholic extracts for their antioxidant activity including: Aloe leaf, Cocoa powder (Hershey brand), Cinnamon spice, Cranberry (27% juice), grapefruit seed oil (Citricidal®), Hops flowers ( Humulus lupulus ), dried Lavender flowers, ripe red seedless grapes, rhubarb stems, lycopenes purified from tomato paste, carotenes purified carrots, oleic acid, catkins from Linden tree ( Tilia americanus sp), and catkins from oak tree ( Quercus sps.), tea tree oil, various commercial food grade vegetable oils, and tomato paste. The majority of these extracts had antioxidant activity less than green tea leaves. EXAMPLE 2 Use of Retinoid-Stimulated Autocrine(RSA) Growth Assay for Detection of Plant Extracts with Putative Anti-Irritant Activity [0054] Since retinoids irritate skin leading to epidermal hyperplasia, it is the inventors idea that plant extracts that act as inhibitors of retinoid -stimulated autocrine growth are themselves anti-irritants. This hypothesis was tested using an in vitro keratinocyte culture model. [0055] An immortalized line of human epidermal kertatinocytes, HaCat keratinocytes, can be cultured in a serum-free culture medium. Sterile Petri dishes (35 mm 2 ) are seeded at 5,000 cells per cm 2 and placed in a humidified CO 2 incubator at 37° C. for 3-5 days or until the culture reaches about 30% confluent monolayer growth. The dishes are washed once with ice-cold serum-free media lacking EGF and insulin, and refed 2.5 ml of serum-free culture medium containing 5 ug/ml insulin and retinyl acetate (RA, 3×10 −8 M).—Duplicate control dishes are fixed and stained with 0.2% crystal violet to record the—amount of clonal growth prior to refeeding with fresh RA-containing medium. Test—dishes refed RA and insulin are split into three groups in duplicate. Group A is refed on the RA plus insulin medium. Group B is refed RA plus insulin medium and a TRK inhibitor (PD 15356), and Group C is refed medium containing RA plus insulin and from 0.1 to 5% of a hydroalcoholic botanical extract. All dishes are adjusted to have the same final concentration of alcohol (1%). All dishes are placed back in the incubator for 2 and 4 days. They are fixed and stained with 0.2% crystal violet. The stained dishes are photographed for comparison of results. [0056] As a proof of principle the effect of Quercetin dihydrate (10 μM) a known inhibitor of growth factor receptor TRK on HaCat clonal growth was compared with growth of HaCat cells grown without Quercetin dihydrate, and both cultured under retinoid-stimulated autocrine growth conditions. As predicted, FIG. 3 shows that 48 hours after treatment with Quercetin dihydrate clonal growth was completely inhibited relative to the untreated control. [0057] In a second study, the effect of a hydroalcoholic extract of green onion leaves (dubbed Allin) on RSA clonal growth was examined. Green onion leaves have been reported to have 1498 mg/k of the aglycone flavonol Quercetin (Miean et al, 2001). FIG. 4 shows that Allin was effectively inhibited autocrine growth of HaCat keratinocytes. [0058] FIG. 5 presents the results of a third study, where the effect of a semi-purified lycopene extract from tomato paste was compared with a hydroalcoholic extract of corn tassels (dubbed Tasselin). A hydroalcoholic solution of Quercetin dihydrate (10 μM) was included as a positive control. The results show that while lycopene had little or no effect, Tasselin was an effective inhibitor of RSA-RTK mediated autocrine regulation of growth of HaCat keratinocytes. [0059] Further studies showed that hydroalcoholic extracts of ripe Autumn Olive berries, extracts prepared from green tea leaves and hydroalcoholic extracts from male flowers (catkins) of Oak and Linden trees were also effective in inhibiting RSA clonal growth of HaCat keratinocytes. EXAMPLE 3 Anti-Irritant Activity of Botanical Extracts [0000] Anti-Irritant Assays. [0060] All carrier system gels were prepared with 0.5% benzalkonium chloride, a mild irritant. To test for anti-irritancy, the irritant-containing carrier gels were also loaded with the test botanical extracts (experimentals). The control and test gels were deposited (100 microliters) on 10 mm square circular filter paper discs and placed in side of Finn chambers (20 mm square), which were then applied to the volar arm skin of volunteers. The chambers were affixed to skin with non-allergic adhesive tape and left in place for 24 hours. Upon termination of the treatments, the chambers were removed and the skin gently wiped clean with moistened cotton swabs. The exposed skin was first examined for signs of erythema (redness) and induration (swelling), and skin sites photographed. The exposed skin sites were probed for skin capacitance (skin moisture levels) using a Corneometer instrument (Courage & Khazaka, Koln, Germany). [0000] Anti-Irritant Activity of Botanicals: [0061] Occlusive patch testing was conducted on extracts prepared by starch gel encapsulation in an oil-in water emulsion system previously described (Wille, 2003). FIG. 6 presents results showing that a 5% GTL extract in vehicle gel elevated skin hydration following 24-hour occlusion when co-administered in the carrier gel with a irritating concentration of Benzalkonium Chloride (0.5%). Similar results were obtained with 5% AOB extract ( FIG. 7 ). The increase in skin hydration may be due to an unexpected moisturizing effect of the botanicals as no visible signs of skin irritation were observed. [0062] FIG. 8 presents a photograph of volar arm skin exposed for 24 hours under occlusion to vehicle containing 0.5% Benzalkonium chloride (BC), the positive irritation control versus vehicle containing 0.5% BC in combination with 5% Tasselin (corn tassel extract). The photograph shows that Tasselin in the presence of BC suppressed BC-induced redness and skin eruptions seen in the irritant control, i.e., Tasselin is an anti-irritant. [0063] In summary, the results of our studies have demonstrated that the cold-processing and hydroalcoholic extraction methods developed to extract botanicals from dried, powdered or wet weight of plant materials is satisfactory in preserving the anti-oxidant as well as the anti-irritant activity of select botanicals. Among the extracts analyzed, Autumn Olive berries have good antioxidant activities similar to that found for green tea leaf extracts. Although, we have not yet been performed detailed chemical analyses, preliminary work suggests that Autumn Olive berries are rich in polyphenols, while Corn tassel extracts have gallocatechins and polyphenols. The anti-irritant properties of Autumn Olive berry and corn tassel extracts may be due to their antioxidant activity as a oxidative loss of anti-oxidant activity coincides with a loss in anti-irritant activity. EXAMPLE 4 Partial Chemical Characterization of Corn Tassel Extracts [0064] A methanol extract of corn tassels was dried by rotary evaporation and taken up in methanol. The concentrated extract was diluted in chromatographic solvent and used to perform HPLC (high pressure liquid chromatography) studies. Table 2 ( FIG. 9 ) presents the results showing the elution times for the four resolved peaks scanned by the UV-detector at 225 nm. FIG. 9A presents results showing the elution profile of corn tassel (Tasselin) versus authentic phenoxyacetic acid alkyl esters. FIG. 10 shows the UV-spectrum of the corn tassel extract. Note: the peak absorbance is at approximately 190 nm with a secondary peak at about 210 nm. EXAMPLE (5) [0000] Preparation of Anti-oxidant Extracts from Powdered Corn Tassel Spiklets [0065] Corn tassel spikelets were collected and stored at −20 degrees centigrade. The material was placed in a clear polyethylene bag and the pollen and spikelet contents shaken loose and recovered separately. The collected pollen and pollen sacs were reddish brown in color and the average particle size was less than 0.5 cm in length. The material so obtained was stored again for varying periods of time at −20 degrees centigrade. For the purposes of the following study, 0.2 grams of dried tassel pollen plus pollen sacs were thawed at room temperature, placed in a ceramic mortar and ground vigorously to a powder with a ceramic pestle. The powdered material was recovered and filtered through a metal cloth mesh (24×24 wires/inch). Greater than 90% of the powdered material passed through the mesh. It was added to a sterile 15 ml conical centrifuge tube and the powdered material was sequentially extracted with 5.0 ml each of a) distilled water, b) 100% methanol and c) 70% ethanol at 25 degrees centigrade. Each final extract was therefore prepared as a 4% (w/v) sample, and were clarified by low speed centrifugation at 5 degrees centigrade for 10 minutes at 3,000 rpm. The resulting solutions were examined for free-radical scavenging activity by the standard diphenyl picryl hydrazine (DPPH*) assay according to the method of Bonina et al (2003). Table (X) presents the results as Percent Decoloration of the DPPH solution after 30 minutes of reaction at room temperature as measured in a Spectrophotometer at 595 nm. The absorbance data are recorded as Optical Density readings. [0066] Note: The water extract had to be diluted 20 fold to obtain a linear reading. The interpolated concentration at which a 50% reduction in color occurred was calculated at a pwder concentration of 0.16%. The Methanol extract of the water-extracted tassel powder material had an equivalent antioxidant activity to the water extract, while the 70% ethanol-water extract had a lower activity, presumably because water and methanol extracts contained the bulk of the antioxidant activity. [0067] The presence of gallo-tannins in the powder extracts was confirmed by development of a positive black color upon drop-wise addition of 10% FeCl 3 to a 5% dilution of the 4% (w/v) extracts. [0068] There has thus been shown and described a novel anti-irritant botanical extracts and methods for making the same, of which fulfill all the objects and advantages sought therefore. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.
Anti-irritant botanical extracts, and a method for screening, and then preparing, anti-irritant botanical extracts for use in topical formulations, providing a natural ingredient capable of preventing skin irritation when in combination with other active and inactive ingredients that have the potential to irritant skin
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CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application relates and claims priority to U.S. Provisional Patent Application No. 61/268,774, filed on Jun. 16, 2009. FIELD OF THE INVENTION [0002] This invention relates to hydrocarbon dehydrogenation processes and more particularly to catalytic naphtha reforming processes. BACKGROUND OF THE INVENTION [0003] Hydrocarbon dehydrogenation processes are important commercially in the petroleum refining and petrochemicals industries for the production of unsaturated hydrocarbons such as olefins and aromatics from saturated or more fully saturated precursors. The most important commercial process utilizing hydrocarbon dehydrogenation is the catalytic reforming process in which straight-run naphthas are converted to more highly aromatic products over a catalyst usually containing platinum as an active component. The products may be either high octane gasolines or petrochemical feedstocks. [0004] The catalytic reforming process is generally regarded as comprising four individual reactions: 1. Dehydrogenation of naphthenes to produce aromatics and hydrogen. The dehydrogenation reactions are strongly endothermic (˜70 kJ/mol) and have the highest reaction rates of the reforming reactions; this necessitates the use of interstage heaters between successive reactors to maintain the reactant hydrocarbons at the required high temperatures for the reactions to proceed at acceptable rates. 2. Isomerization of paraffins, mainly isomerization of n-paraffins to branched chain products and isomerization of alkyl cyclopentanes to cyclohexanes which are subsequently converted to benzenes. This reaction is rapid and is mildly exothermic but is favored by the use of high temperatures to increase reaction rate. 3. Dehydrocyclization of paraffins. This reaction involves difficult molecular rearrangements of paraffins to naphthenes. Higher molecular weight paraffins are relatively easier to rearrange since ring formation tendency is higher. Dehydrocyclization reactions are endothermic (˜44 kJ/mol) and favored by low pressure, high temperature and require acid and metal catalyst functions. 4. Hydrocracking and dealkylation. Paraffin hydrocracking is a high probability reaction due to the difficulty of naphthene isomerization and paraffin cyclization reactions. This reaction is kinetically the slowest and is mildly exothermic but is favored kinetically by the use of higher temperatures along with high pressures. Dealkylation involves either reducing the chain length on the aromatics or completely removing the side chain. Dealkylation is favored by high temperature and high pressure. [0009] Overall, the reforming process is favored by the use of high temperatures by a balance of the thermodynamic equilibria and the kinetics of the respective endothermic and exothermic reactions participating in the process. While metallurgical design considerations may at some point become a limiting factor in operating at higher temperatures other factors also enter into consideration including the economics and environmental factors of fossil fuel use for process heating, the activity and selectivity of the catalyst system at higher temperatures and the extent to which competing reactions will become progressively favored. Process economics would obviously be favored by reductions in the use of fossil fuels for satisfying process heat requirements which would also result in a reduction in the generation of carbon dioxide emissions. Substitution of fossil fuel process heat by other heat sources such as nuclear and solar energy is therefore an economically, environmentally and politically attractive option since in a carbon-constrained economy, the potential to dramatically reduce flue gas and extend fossil resource capacity may depend on nontraditional uses of alternative energy. [0010] A major consideration in reforming is the balance which must be achieved between the hydrogenation/dehydrogenation function of the catalyst and its cracking function at any selected temperature. Generally, with present platinum-based reforming catalysts, the platinum provides the catalytic sites for the hydrogenation/dehydrogenation activity while an acidic function required for the initial cracking step of the hydrocracking and for the paraffin dehydrocyclization is provided by partly by the alumina of the carrier and some may be provided by the feed but since these quantities are usually insufficient, the support material or separate carrier is usually halogenated with the degree of halogenation optimized to provide the desired degree of activity to promote isomerization. Typically, platinum-containing alumina-based reforming catalysts are usually manufactured having a predetermined amount of halide, particularly chloride, on catalyst, sometimes up to about 3 wt. %, depending on the active metals content of the catalyst. As the catalyst ages, chloride loss becomes appreciable and, inter alia, contributes to loss of catalyst activity and chloridation during the catalyst cycle becomes necessary to maintain activity. [0011] At higher temperatures catalyst activity and selectivity may become unfavorable as paraffin cracking becomes more significant even though aromatization of naphthenes will be promoted thermodynamically. A balance between the desired aromatization reactions and the less desired cracking reactions can therefore be achieved in principle by operation at higher temperatures with a catalyst in which cracking activity is inhibited. [0012] Current catalytic reforming such as UOP's Platforming™ process operate with a platinum-containing catalyst at temperatures in the range of 525 to 540° C. and hydrogen pressures of 345 to 3450 kPa n the case of fixed bed processes and rather lower pressures in the moving bed CCR Platforming™ process. There is a need to reduce, eliminate or use lower cost dehydrogenation catalysts in catalytic reforming process technology. This would be possible if the dehydrogenation process can be run more efficiently, e.g., with greater production of aromatics, at higher temperature while considering the factors discussed above relative to the overall scheme of the process. SUMMARY OF THE INVENTION [0013] We now propose that hydrocarbon dehydrogenation processes such as reforming are to be provided with process heat from nuclear and solar thermal energy sources. One of the unique attributes of nuclear and solar thermal technologies is their ability to provide high temperature (800 to 1500° C.) high pressure steam. Heat at these temperatures can be utilized effectively for the highly endothermic high temperature dehydrogenation of acyclic and cyclic paraffins to aromatics. The process occurs may be operated in the absence of catalyst or with reduced amounts of lower cost dehydrogenation catalyst or with a catalyst additive for inhibiting excessive cracking and dealkylation reactions at higher temperature. [0014] Among the advantages of using nuclear and/or solar thermal heat for hydrocarbon dehydrogenation processes are the following: 1 use of lower cost dehydrogenation catalysts arising from conducting the dehydrogenation at high process temperatures; 2 conservation of fossil fuel energy required to provide process heat; 3 elimination of carbon dioxide evolution associated with burning of a hydrocarbon resource to generate process heat; 4 driving aromatization vs. isomerization reactions at higher temperature. [0019] The present invention therefore provides a hydrocarbon dehydrogenation process in which a hydrocarbon feed, normally a straight run naphtha, comprising acyclic and cyclic paraffins is dehydrogenated at elevated temperature of at least 540° C. with process heat provided at least in part by a solar or nuclear thermal energy source. The process is preferably operated with a co-catalyst or additive which is effective to inhibit cracking reactions including dealkylation reactions at the selected operating temperatures. The use of cheaper catalysts which are less active at conventional reforming temperatures also becomes possible at the higher temperatures enabled by the use of nuclear or solar heat sources. DETAILED DESCRIPTION [0020] Although the present invention may be applied to dehydrogenation processes other than reforming, for example, the high temperature dehydrogenation of ethane to ethylene in the steam cracking of ethane and the conversion of ethylbenzene to form styrene, its main application will be to the naphtha reforming process as carried out conventionally for the production of high octane gasoline and aromatic petrochemical feedstocks. The general catalytic reforming process configuration will remain unchanged with an incoming low sulfur (<10 ppmw sulfur, preferably <2 ppmw) naphtha feed being heated to reaction temperature after which the feed is passed over the reforming catalyst in successive reactors with interstage heating between successive reactors. The process may be operated in a in fixed bed units either in a semi-regenerative mode with the catalyst being regenerated and reactivated at extended intervals, in a cyclic mode with the catalyst being regenerated in the reactors at shorter intervals, feed and regeneration gases being switched between reactors in a cyclic manner. Continuous catalytic reforming is also possible with a moving bed of catalyst passing through successive reactor vessels, either in a stacked or side-by-side configuration and then to a regenerator in which coke is burned off and the catalyst re-activated by halogenation to the extent necessary to maintain activity before being returned to the reactor section. The proposed high temperature operation may also be applied to a hybrid fixed/moving bed unit such as shown in U.S. Pat. No. 4,498,873; U.S. Pat No. 5,190,638; U.S. Pat. No. 5,1909,639; U.S. Pat. No. 5,196,110; U.S. Pat. No. 5,211,838; U.S. Pat. No. 5,221,463; U.S. Pat. No. 5,354,451; U.S. Pat. No. 5,368,720; U.S. Pat. No. 5,417,843 as well as in the technical, for example, in the NPRA Papers No. AM-96-50 and AM-03-93. Units converted to moving bed reactor configuration from older, fixed bed units as described in US 2004/0129605 A1, US 2005/0274648 A1 and WO2006/102326 are also amenable in principle to modification for operation with solar and nuclear heat sources provided that metallurgical constraints are observed. [0021] The heat from the solar or nuclear thermal energy sources will be supplied to the process in the form of feed pre-heat and by interstage heating. When solar energy sources provide the heat, the feed and/or the reaction stream may be passed directly through a solar furnace, e.g. at the focus of the furnace, to provide the heat directly or by heat exchangers passing a heat transfer medium from the solar source to the exchanger. With nuclear energy sources where circulation directly through the nuclear reactor is not possible, the feedstream and reaction stream will be passed through heat exchangers fed from the nuclear reactor. The heat exchanger will normally be fed with heat transfer medium in a secondary loop heated in a heat exchanger with the nuclear reactor primary coolant in its own loop passing through the nuclear reactor core but if the primary coolant does not become radioactive in the reactor core, e.g. with helium in a gas-cooled reactor, the heat exchangers for the reformer heat stream and interstage reaction streams may be fed with the primary coolant. Solar Thermal Energy Sources [0022] Solar thermal energy is provided by the conversion of light to heat energy. This is typically achieved by focusing solar radiation onto a point source using mirrors, and the point source increases in temperature thus generating heat. For commercial applications, multiple mirrors are required to be installed to increase light capture. Once the solar radiation is focused on a point, the heat is transferred to fluid heat transfer medium. Three types of solar thermal device designs have been explored: solar tower, solar trough, and solar reactors. [0023] Solar thermal installations with a tower design use mirrors to focus incoming solar radiation on to a point that is often located on a central tower. Typically, the mirrors in a heliostat system are motorized to follow the sun over the course of the day. At this focal point, a liquid heat transfer medium is heated to the required temperature. Solar trough power plants use curved, trough-shaped mirrors to focus light on to a heat transfer fluid that flows through a tube above them. These trough reflectors tilt throughout the day to track the sun for optimal heating. The heat transfer fluid is heated in the troughs and then flows to a heat exchanger, which is used to produce superheated steam. A modified version of the parabolic trough design, the Fresnel reflector design, is uses a series of flat mirrors with a number of heat transfer receivers. Solar reactors, or Concentrated Solar Power (CSP), are useful for applications such as the present that take advantage of the high-temperature capabilities of tower technology which uses reactors similar to closed volumetric receivers except that a rhodium or another catalyst is dispersed on the surface of the ceramic mesh, directly absorbing the solar energy to produce syngas, hydrogen, and carbon monoxide as disclosed by Moller, S. et al., in 2002: Solar production of syngas for electricity generation: SOLASYS Project Test-Phase, 11 th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies, Zurich. In its application to the present invention a solar reactor is used for directly heating the heat transfer fluid to high temperatures. [0024] The solar energy source may be augmented with natural gas or nuclear heat at times the solar thermal reactor output is diminished due to lack of availability of solar radiation. Nuclear Thermal Energy Sources [0025] The high temperatures required for the present invention can also be provided by certain nuclear thermal energy sources. While conventional light water reactors are not adequate to supply these high temperatures, high temperature gas-cooled reactors and others have appropriate characteristics. One example is the Toshiba 4S (super safe, small, and simple) nuclear power system is based on a low-pressure, liquid-sodium design which is therefore capable of supplying the required high temperatures. It can be transported in modules and installed in a building measuring 22×16×11 metres and therefore commends itself for appropriate adaptation to refinery usage. High-temperature gas-cooled reactors (HTGRs) which typically use helium as a coolant are another next-generation reactor design that have the potential for driving endothermic chemical reactions, e.g., the regeneration reactions in the sulfur sorption cycle. One factor making HTGRs advantageous for the present application is that in principle the HTGCR can operate at temperatures well above 800° C., a range of refining operations including cracking, reforming and solid contact sulfur sorption as described above. The Siemens PBMR (the pebble bed modular reactor, or PBMR) is an example of a HTGCR which would be particularly useful for these purposes. The pebble bed modular reactor (PBMR) potentially meets US safety standards and includes a required airtight steel-lined reinforced-concrete containment structure. Operation of the PBMR is based on a single helium coolant loop, which exits the reactor core at 900° C. and 70 bar and therefore can be used to heat a heat transfer medium to comparable temperatures for use in refining processes. The PBMR is described in Weil, J., 2001: Pebble - Bed Design Returns, IEEE Spectrum, 38 (11), 37-40. [0000] Heat Transfer from Source to Process Unit [0026] As noted above, the heat from solar sources may be applied directly to the feed and reaction streams by passing them through heating coils in the solar furnace. I other cases, the heat from the solar or nuclear high temperature heat source will be applied by the use of a heat transfer medium and heat exchange device transferring the heat from the solar or nuclear power source to the reforming process unit. The heat transfer medium will be routed from the solar or nuclear source to a heat exchanger providing pre-heat for the process, direct heat to the process environment e.g. by a heating jacket on the reactor used for carrying out the process or by heat transfer coils or tubes inside the reactor. Heat from solar and nuclear heat sources at temperatures potentially in excess of 1500° C. and heat of this quality can be used very effectively to provide process heat to the reforming reactions, even when transferring heat to the process streams in a heat exchanger. Heat transfer at the high temperatures contemplated, typically above 800° C. and ideally higher, e.g. 900, 1000° C., even as high as 1500° C., can be effected using transfer media such as liquids, gases, molten salts or molten metals although molten salts and molten metals will often be preferred for their ability to operate at the very high temperatures required for high energy densities without phase changes; in addition, corrosion problems can be minimized by appropriate choice of medium relative to the metallurgy of the relevant units. Molten salt mixtures such as mixtures of nitrate salts, more specifically, a mixture of 60% sodium nitrate and 40% potassium nitrate are suitable but other types and mixtures of molten salts may be used as a heat transfer and a thermal storage medium. Liquid metals such as sodium as well as alloys such as sodium-potassium alloy, bismuth alloys such as Woods metal, (m.p. 70° C.) and alloys of bismuth with metals such as lead, tin, cadmium and indium; the melting point of gallium (30° C.) and its alloys would, but for the aggressiveness of this metal towards almost all other metals, generally preclude it from consideration. Mercury is excluded for environmental reasons. Hot helium from a HTGCR can be used in a single loop heat exchange circuit from the nuclear reactor to the hydrocarbon process unit since helium is incapable of becoming radioactive and HTGCR reactor design is inherently safe: in the event of a loss of coolant, the temperature in the core will increase until Doppler broadening leads to a breakdown in the fission chain reaction. Outlet temperature and pressure for the helium coolant of the HTGCR are 850° C. and 70 bar, respectively, making it suitable for the present purposes. If required for safety or other reasons, the primary heat exchange fluid can be used to heat a secondary heat exchange fluid in a secondary circuit with this secondary fluid passing to the hydrocarbon process unit. Application to Reforming [0027] By conducting the reforming process at temperatures above 540° C. and desirably, higher, the potential exists for reducing the amount of catalyst or enabling use of lower cost catalysts and so providing significant cost savings associated with catalyst use. Thus, by expanding the operating temperature envelope significant process economic benefits are to be expected. In addition, the use of higher temperatures may favor the production of the more highly valued aromatics, potentially in greater yields as the conditions for reactions producing aromatics and their precursors become more favorable. [0028] Reaction temperatures which are higher than the current norm for the process are enabled by the use of process heat from nuclear and solar sources: temperatures potentially as high as 1300° C. could be achieved but for practical reasons resort will normally not be made to such values. Temperatures of at least 600, 650, 700, 750 or 800° C. are readily achievable and metallurgies are capable of handling such values. The optimal range of temperatures would be from 650-800° C., in most cases 700-800° C. Pressures will depend on the type of operation, fixed bed, continuous or hybrid. Fixed bed reforming processes generally require relatively high pressures of at least 15 bar for adequate catalyst life between successive regenerations whereas continuous reforming is operated at the lower pressures allowed by the shorter time between successive regenerations, typically about 3 to 10 bar. [0029] Operation at the higher temperatures enabled by the use of solar and/or nuclear thermal energy sources permits catalysts which do not exhibit adequate activity at lower temperature ranges to be used successfully. In particular, base metal catalysts come into consideration, for example, chromium, molybdenum and chromium/molybdenum catalysts as well as those containing other transition metals of groups 5-10 of the long form Periodic Table, for example, iron, vanadium, cobalt, nickel. The base metals may be used in combination with platinum and the promoter metals normally associated with platinum in reforming catalysts including rhenium, iridium, rhodium, tin but the amount of the noble metal may be reduced relative to that conventionally used in the platinum-based catalysts for a more economic catalyst, for example, below about 0.6 wt. percent, e.g. below 0.3 or 0.25 wt. pct. Pt. If used alone, the base metals would typically be at levels of 0.5 to 20, more usually 2 to 10 wt. pct base metal on the total catalyst. Carrier materials will be alumina, silica or silica-alumina with preference given to the alumina-containing materials as these anchor the metal component more effectively. [0030] The use of the higher temperatures will favor the strongly endothermic dehydrogenation reaction which is the most desired reaction in the reforming process. It will also favor the less desired cracking reactions even though some measure of cracking (acidic) functionality must be retained in order to promote the isomerization reactions. Cracking is a first order reaction dependent on time at a given temperature and since most of the reforming reactions are favored kinetically at higher temperatures, their use will enable shorter reaction times to be utilized while attaining similar equilibrium concentrations. In addition, the relative reaction rates will play a role: hydrocracking as the slowest reaction will tend to be kinetically disfavored by the shorter reaction times which can be sued at the higher temperatures and therefore can be expected to result in a net increase in the more difficult napthene isomerization and paraffin cyclization reactions, both of which are desirable. Space velocities can be increased commensurately with the shorter reaction durations, so permitting greater capacities to be achieved within given equipment size or smaller vessel size for the same capacity. [0031] Another potential advantage offered by the use of the higher temperatures is that the acid function of the catalyst may be decreased while retaining the dehydrogenation activity. In this way, the undesired cracking reactions will be less favored relative to dehydrogenation. Control of catalyst acidity may be affected by reduction or elimination of the halide content of the catalyst, the use of less acidic carriers, for example, by using the less acidic forms of alumina such as boehmite (gamma alumina oxide hydroxide) and by less halogenation during the actual processing. Another possibility is to add a co-catalyst or catalyst additive such as calcium carbonate or another alkaline solid to the carrier formulation. [0032] The process might be operated non-catalytically at the contemplated higher reaction temperatures although some loss in reaction selectivity patterns may be encountered. In this case, the process could be carried out in an extended tubular reactor fitted with heating coils, preferably finned coils, fed by the nuclear or solar heat source distributed along the path of reactant flow to maintain reactant temperature. [0033] Naphtha feeds will be conventional in type but may be liberated from the ultra-low sulfur feed specification when the base metal catalysts are used as these are less susceptible to sulfur poisoning than the platinum-based catalysts. The use of the nuclear and solar heat sources may therefore permit a reduction in hydrotreating capacity to be made with consequent further economies of operation. A wider range of naphthas may also fall for consideration with this possibility.
A hydrocarbon dehydrogenation process in which a hydrocarbon feed, normally a straight run naphtha, comprising acyclic and cyclic paraffins is dehydrogenated at elevated temperature of at least 540° C. with process heat provided at least in part by a solar or nuclear thermal energy source.
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SUMMARY OF THE INVENTION [0001] The present invention relates to construction forms and more specifically to a device for making concrete forms for making stairs. Pouring concrete requires a form to hold the liquid concrete until it can dry to its solid form. The top surface of the wet concrete is left open to allow excess material removal. Creating a form to pour stairs involves securing a set of risers to a set of stringers. The risers contain the wet concrete and when removed correspond to the rise of each step. The top surface of the wet concrete hardens to form the tread of each step. Currently, a stair form is created by cutting portions out of a piece of wood (see FIGS. 8 - 9 ). Removing the outline of the stairs, including the thickness of the risers and a finishing space, forms a stringer. The stringer is then hung in place by anchoring at a floor elevation and securing at a landing elevation. Additional stringers are added at regular intervals between the right and left sides of the desired stairs. A portion of each riser is removed to allow a finish tool access to the portion of the tread adjacent the next rise. The risers are then secured at a right angle to the stringer using an additional block of wood attached to both the stringer and the riser. After the concrete dries, the risers and stringers are removed and the stringers must be discarded because of the unlikelihood of needing that exact configuration. This method of creating stair forms is time consuming and wasteful. There is a need for a system that is quicker and allows reuse of the stringers. [0002] U.S. Pat. No. 4,916,796 discloses a method for assembly of stair forms. The apparatus allows the risers to be positioned without having to cut the stringer. This apparatus requires attachment at a pivot point 22 to a line marked on the stringer. The apparatus is then positioned using scales 56 located on an arcuate edge of the scales and the line on the stringer. Kneeboard 72 is added to allow a worker to kneel on the kneeboard to finish the concrete tread. There are a couple of drawbacks to this system. The kneeboard must be removed in order to finish the portion of the tread previously covered by the kneeboard. Concrete work is notoriously messy and the back surface of the apparatus does not pivot well when dirty. In addition, access to the previous apparatus is necessary to install a subsequent apparatus. There is a need for a system that does not require a separate kneeboard. There is also a need for a system that is easy to use and allows repeated use of the apparatus. The present invention meets those needs. [0003] One aspect of the present invention is an apparatus having a bracket having a first end opposite a second end. The bracket further includes a stringer mount face and a riser mount face including first and second riser mounting regions. The stringer mount face and the riser mount face extending longitudinally between the first end and the second end. At least a portion of the stringer mount face defines a stringer mount plane and at least a portion of the riser mount face defines a riser mount plane. The bracket is configured such that the stringer mount plane is generally perpendicular to the riser mount plane. A riser mounting structure is located on the riser mount face. A stringer mounting structure is located on the stringer mounting face. A longitudinally extending stringer stop extends away from and perpendicular to the stringer mount plane. The stringer stop has first and second abutting surfaces. One of the first and second abutting surfaces can abut a bottom of a stringer such that the stringer mounting face can be positioned adjacent a side of the stringer. The apparatus further includes a laterally extending first riser stop having a first riser abutting surface. The first riser stop extends away from the riser mount face and is longitudinally spaced a first distance from the stringer stop. The first riser mounting region is located between the first riser stop and the second end. The first riser abutting surface is adapted to abut a top of a riser such that the first riser mounting region of the riser mounting face is positioned adjacent a side of the riser. [0004] Another aspect of the present invention is an assembly comprising an apparatus, a stringer and a riser. The apparatus has a bracket having a first end opposite a second end. The bracket further includes a stringer mount face and a riser mount face including first and second riser mounting regions. The stringer mount face and the riser mount face extend longitudinally between the first end and the second end. At least a portion of the stringer mount face defines a stringer mount plane and at least a portion of the riser mount face defines a riser mount plane. The bracket is configured such that the stringer mount plane is generally perpendicular to the riser mount plane. The apparatus further comprises a riser mounting structure located on the riser mount face and a stringer mounting structure located on the stringer mounting face. A longitudinally extending stringer stop extends away from and perpendicular to the stringer mount plane. The stringer stop has first and second abutting surfaces. A laterally extending first riser stop has a first riser abutting surface. The first riser stop extends away from the riser mount face and is longitudinally spaced a first distance from the stringer stop. A laterally extending second riser stop has a second riser abutting surface. The second riser stop extends away from the riser mount face and is longitudinally spaced a second distance from the stringer stop. The first distance is equal to the second distance. The first riser mounting region is located between the first riser stop and the second end and the second riser mounting region is located between the second riser stop and the first end. The assembly further comprising a stringer having a stringer bottom, a first stringer side and a second stringer side. The stringer is attached to the apparatus such that one of the first and second stringer sides is adjacent the stringer mounting face and the stringer bottom is abutted by one of the first and second abutting surfaces of the stringer stop. The assembly further comprising a riser having a riser top and a riser side. The riser is attached to the apparatus such that the riser side is adjacent one of the first and second riser mounting regions and the riser top is abutted by one of the first and second riser stops. [0005] Another aspect of the present invention is a method of creating a form for pouring concrete steps. The method comprising providing an apparatus having a bracket having a first end opposite a second end. The bracket further includes a stringer mount face and a riser mount face including first and second riser mounting regions. The stringer mount face and the riser mount face extend longitudinally between the first end and the second end. At least a portion of the stringer mount face defines a stringer mount plane and at least a portion of the riser mount face defines a riser mount plane. The bracket is configured such that the stringer mount plane is generally perpendicular to the riser mount plane. The apparatus further comprises a riser mounting structure located on the riser mount face and a stringer mounting structure located on the stringer mounting face. A longitudinally extending stringer stop extends away from and perpendicular to the stringer mount plane. The stringer stop has first and second abutting surfaces. A laterally extending first riser stop has a first riser abutting surface. The first riser stop extends away from the riser mount face and is longitudinally spaced a first distance from the stringer stop. A laterally extending second riser stop has a second riser abutting surface. The second riser stop extends away from the riser mount face and is longitudinally spaced a second distance from the stringer stop. The first distance is equal to the second distance. The first riser mounting region is located between the first riser stop and the second end and the second riser mounting region is located between the second riser stop and the first end. The method further comprising providing a stringer having a stringer bottom, a first stringer side and a second stringer side. Providing a riser having a riser top and a riser side. Securing the apparatus to the stringer; and securing the apparatus to the riser. [0006] Other features and advantages will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS [0007] [0007]FIG. 1 is a perspective view of an apparatus according to the invention; [0008] [0008]FIG. 2 is a front plan view of the apparatus of FIG. 1; [0009] [0009]FIG. 3 is a side plan view of the apparatus of FIG. 1; [0010] [0010]FIG. 4 is a perspective view of an extension clip according to the invention; [0011] [0011]FIG. 5 is a front plan view of an extension clip and apparatus according to the present invention; [0012] [0012]FIG. 6 is a side view of an assembly according to the present invention; [0013] [0013]FIG. 7 is a perspective view of the assembly of FIG. 6; [0014] [0014]FIG. 8 is a side view of an example of the prior art; and [0015] [0015]FIG. 9 is a perspective view of the example shown in FIG. 8. [0016] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] Referring now to the drawings, FIG. 1 shows an apparatus 20 according to the present invention. The apparatus has a first end 22 opposite a second end 24 of a bracket 26 . The apparatus includes the bracket 26 , a stringer stop 28 , and at least a first riser stop 30 . The apparatus may also include a second riser stop 32 . [0018] The bracket 26 has a stringer mount face 34 and a riser mount face 36 . The riser mount face includes a first mounting region 38 and a second riser mounting region 40 . The stringer mount face and the riser mount face extend longitudinally between the first end 22 and the second end 24 . At least a portion of the stringer mount face defines a stringer mount plane and at least a portion of the riser mount face defines a riser mount plane. The bracket is configured such that the stringer mount plane is generally perpendicular to the riser mount plane. [0019] Referring now to FIGS. 2 - 3 (a side and front plan view respectively of the apparatus of FIG. 1), the riser mount face 36 and the stringer mount face 38 is shown. A riser mounting structure 42 is located on the riser mount face. A stringer mounting structure 44 is located on the stringer mounting face. The stringer stop 28 extends longitudinally away from and perpendicular to the stringer mount plane. The stringer stop has a first abutting surface 46 and a second abutting surface 48 . If one of the first and second abutting surfaces abuts a stringer bottom the stringer mounting face can be positioned adjacent a stringer side. [0020] The first riser stop 30 extends laterally from the riser mount face 36 . The first riser stop has a first riser abutting surface 50 . The first riser stop extends away from the riser mount face and is longitudinally spaced a first distance 52 from the stringer stop 28 . The first riser mounting region 38 is located between the first riser stop 30 and the second end 24 and the second riser mounting region 40 is located between the second riser stop 32 and the first end 22 . The first riser abutting surface 50 is adapted to abut a riser top such that the first riser mounting region 38 of the riser mounting face is positioned adjacent a riser side. [0021] The apparatus can also include the second riser stop 32 . The second riser stop has a second riser abutting surface 54 . The second riser stop extends away from the riser mount face and is spaced longitudinally a second distance 56 from the stringer stop 28 . The second distance 56 is equal to the first distance 52 . The second riser mounting region 40 is located between the second riser stop and the first end 22 . The second riser abutting surface abuts a riser top such that the riser mounting face may be positioned adjacent a side of the riser. [0022] In the embodiment shown, the riser mounting structure 42 is a plurality of first riser holes in the riser mounting face 36 . The first riser holes are spaced longitudinally and located between the first riser stop and the second end 24 . The riser mounting structure 42 can also include a plurality of second riser holes space longitudinally and located between the second riser stop and the first end 22 . The riser holes are dimensioned to receive a wood screw. The stringer mounting structure 44 is a plurality of first stringer holes in the stringer mounting face 24 . The first stringer holes are spaced longitudinally and located between the stringer stop and the first end 22 . The stringer mounting structure may also include a plurality of second stringer holes spaced longitudinally and located between the stringer stop and the second 24 . The stringer holes are dimensioned to receive a wood screw. [0023] Referring now to FIGS. 4 - 5 , the apparatus 20 may also include a riser extension clip 60 . The riser extension clip has an attaching face 62 and an extension face 64 . The extension face includes an extension mounting structure 66 . At least a portion of the attaching face defines an attaching plane and at least a portion of the extension face defines an extension plane. The riser extension clip is configured such that the attaching plane is generally perpendicular to the extension plane. The riser extension clip attaches to the apparatus such that the attaching face 62 is in a face to face orientation with the stringer mount face 34 and the extension face 64 is adjacent the first riser mounting region 38 . In the embodiment shown, the extension clip attaches to the apparatus via an attaching face mounting structure 68 . The attaching face mounting structure 68 is a plurality of holes that align with the plurality of second stringer holes when the extension clip and the apparatus are in a face to face orientation. The extension clip can then be bolted to the apparatus. [0024] Referring now to FIGS. 6 - 7 , the operation of the apparatus 20 can be demonstrated. The apparatus is shown with a stringer 80 and a riser 82 to create a form for concrete stairs. It should be understood that an existing wall (for enclosed stairs) or a side frame (for freestanding stairs) will be utilized to form the lateral boundaries of each step of the stairs. Using formulas known to those skilled in the art and based upon the total rise and run of the stairs, the dimensions of each step (and the number of steps) can be determined. After ensuring the stringer is straight, each step is drawn on the stringer side from a landing down to a floor. A toe-kick, if included, can be accounted for in this step. An additional line 84 is then drawn parallel to each rise drawn on the stringer at a distance equal to the thickness of the riser 82 . The floor is also drawn where it meets the bottom of the initial step. A floor line is drawn parallel to the floor at a distance x. In the embodiment shown, the distance x is equal to a distance x′ from the first stringer abutting surface 46 to the first riser abutting surface 50 . A surplus 86 below the floor line is then removed. Finally, a notch 88 is added to the stringer. The bottom of each riser 82 is bevelled to allow access to the adjacent tread. [0025] An apparatus 20 is then attached to the stringer such that the stringer mount face 34 is adjacent the stringer side 90 at a position where the riser mount plane intersects the additional line 84 . With the stringer stop 28 abutting the stringer bottom, the apparatus 20 is screwed to the stringer using wood screws in the stringer mounting structure 44 . The riser 82 is then attached to the apparatus 20 using wood screws in the riser mounting structure 42 . When the initial riser 82 is positioned properly the stringer is anchored to the floor by affixing an anchor board 94 to the floor and then placing the notch 88 over the anchor board. In the embodiment shown the apparatus is used in a left hand positions (on the left side of the stringer). The riser is attached to the apparatus in the first riser mounting region 38 . A right hand position can be achieved by flipping the apparatus over such that the second end 24 is arranged upright and the riser is mounted in the second riser mounting region 40 . This process is then repeated for each riser. Additional stringers are added and the above process is then repeated. [0026] If a riser is not long enough to cover the step then the riser extension clip 60 is used. Referring to FIG. 4 a riser and an auxiliary are shown in dashed lines abutting one another. The auxiliary is positioned so that the auxiliary top abuts the riser stop and then attaches to the riser extension clip using the extension mounting structure. [0027] In the preferred embodiment, the stingers are 2″×10″ boards and the risers are 2″×6″ boards. After the risers, stringers and a plurality of apparatus have been utilized to create a form, the tops of the risers are strong enough to withstand the weight of an adult. This allows the workers to finish each tread of each step without the necessity of a kneeboard. The clearance between the bottom of the stringer and the step tread allows the tread to be finished beneath the stringer. [0028] After the concrete has been poured and the stairs have dried the form can be removed. Because there are no moving parts the apparatus 20 can easily be reused. [0029] As various changes could be made in the above constructions and methods 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. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto.
The present invention relates to construction forms and more specifically to a device for making concrete forms for making stairs.
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TECHNICAL FIELD [0001] The present invention relates to medical appliances and, in particular, to biodegradable cross-linked polymers, vascular stents, and methods of manufacturing the same. BACKGROUND [0002] Since the 1970s, biodegradable polymeric materials have been extensively used in medical applications, particularly in biodegradable surgical sutures, medical adhesives, biodegradable bone fixation devices, sustained drug release, recent research in biodegradable stents, etc. [0003] Biodegradable polymeric materials are thermoplastic or cross-linked materials. Thermoplastic biodegradable polymeric materials feature long-chain linear molecules. While such materials are soluble in compatible solvents and can be easily molded and processed using injection, extrusion and other common forming technologies, they suffer from an obvious disadvantage of exhibiting stress relaxation behavior. [0004] Cross-linked polymers are three-dimensional networks formed by adding crosslinking agents during the polymerization of monomer or by introducing crosslinkable reactive groups in molecular chains of a linear polymer and then inducing the reaction of the reactive groups on different chains of the polymer by means of radiations, ultraviolet (UV) light, heat or the like. Cross-linked polymers swell rather than dissolving in compatible solvents. Their molding can be performed either before or after the crosslink reaction and the latter case requires the use of special equipment. Although cross-linked polymers exhibit higher structural and dimensional stability and reduced stress relaxation behavior compared to linear polymers, they are disadvantageous in requiring special equipment and technologies for their molding. [0005] In previous research, synthesis of cross-linked polymers was mostly for producing hydrogels and investigating shape memory behavior of the materials. Because such synthesis usually involved complicated multi-step synthesis of pre-polymers, its control was difficult, making it only suitable to be carried out in laboratories for research purposes. Additionally, since materials used in, and by-products produced from, such synthesis were toxic and difficult to be completely removed, use of them in the medical field has not been considered. [0006] In References (1) and (2), the authors introduce their synthesis of cross-linked poly(butyl acrylate) networks and investigations of shape memory behavior of the materials. These cross-linked polymers are both prepared by crosslinking an optically or thermally crosslinkable polycaprolactone macromonomers obtained from methacryloyl chloride in the presence of tetrahydrofuran (or 2-dichloroethane) and an excess of triethylamine as a catalyst. During the reaction, a side reaction will occur between methacryloyl chloride and excessive triethylamine, and triethylamine hydrochlorides remaining in the product are difficult to be completely removed. The authors also propose a cross-linked shape memory polymer defined in claims 1 and 17 of patent Reference (3). The major purpose of this application is for claiming the protection of the cross-linked shape memory polymer which has at least two soft polymeric segments. In addition, exemplary cross-linked shape memory polymers presented in the application exhibit an elastic modulus of only about 71 MPa. With similarity to those of References (1) and (2), in this polymer material, only the cross-linked segments are biodegradable, while the butyl acrylate content that makes a predominant part is non-biodegradable. Further, the preparation of this cross-linked polymer is also associated with the issues of involving multiple synthesis steps, causing remains of by-products and using excessive solvents, arising from the use of the same prepolymer synthesis process as those of References (1) and (2). [0007] Claims 1 and 12 of patent Reference (4) describe a cross-linked biodegradable polymer prepared based on a polymer made from the polycondensation of glycerol and a bifunctional diacid as monomers. This biodegradable polymer has a very low elastic modulus that is ≦5 MPa. [0008] Patent Reference (5) discloses a cross-linked polyester elastomer. However, this polymer also has a very low elastic modulus of ≦1.5 MPa. [0009] Existing stents used in the treatment of postoperative vascular restenosis and other conditions typically include metal stents, drug-eluting metal stents and biodegradable metal stents. Although the continuously progressing technology in the field of metal stents has addressed the issue of post-PTCA elastic recoil, intimal hyperplasia and other complications caused by intimal injury and the presence of metallic foreign bodies still remain unsolved. Drug-eluting metal stents can achieve an extent of intimal hyperplasia inhibition and a reduced incidence of restenosis, but due to the inevitable stimulating effect as metallic foreign bodies, their use is associated with prolonged administration of antiplatelet drugs. Further, metal stents may impede beneficial vascular remodeling after implantation. [0010] The occurrence of restenosis is strongly time-dependent. Biodegradable stents are temporary stents which stay in vivo across specific pathological processes and disappear after fulfilling their therapeutic functions, thus avoiding exerting a long-term foreign body effect on the human body. In addition, biodegradable stents can be further used as carriers for sustained drug release and ultimately achieve intimal hyperplasia inhibition through the drug release. [0011] For these reasons, biodegradable stents have received considerable attention. In the recent twenty years, many biodegradable stents have been made from various polymeric materials, such as L-polylactic acids (i.e., poly(L-lactide)), DL-polylactic acids (i.e., poly(L-lactide-co-D-lactide)), copolymers of L-lactide and other monomers, polycaprolactones and other thermoplastic polymeric materials, as well as their blends, or braided from fibers of these materials. In these materials, poly(L-lactide) are most studied. During the period from 1998 to 2000, human experiments related to poly(L-lactide)-based coronary stents were conducted in Japan. In 2006, Abbott commenced human experiments in Europe about a poly(L-lactide)-based drug-eluting coronary stent and acquired the CE Mark in 2011, leading to the debut of the first biodegradable cardiovascular stent product allowed to enter the market. For more information in this regard, reference can be made to non-patent References 1-14 and patent references such as, for example, U.S. Pat. No. 5,059,211A and U.S. Pat. No. 5,306,286A describing a biodegradable stent formed from a roll-up polymeric sheet, US20020143388A1, US20020019661A1, U.S. Pat. No. 6,338,739B1 and US20010029398A1 describing biodegradable stents formed from a blend of two biodegradable thermoplastic polymers, US20030144730A1 and US20050177246A1 describing a helical or tubular stent formed from absorbable fibers each having an inner core and an outer layer, and US20020188342A1 describing a braided stent formed from resorbable fibers. [0012] However, most of commonly used polymeric materials have drawbacks as follows: insufficient mechanical strength, which makes stents made of such materials less resistant to radial compressing forces and easily to be broken by gripping pressure; stress relaxation behavior, which results in unstable performance of the stents and radial strength decreasing with time; and short shelf-lives. Compared to metallic materials, polymeric materials have much weaker mechanical properties. In contrast to elastic moduli of most metallic materials that are higher than 100 GPa, those of strongest polymeric materials are on the order of several GPa and those of aforementioned polylactic acid polymers for making biodegradable vascular stents are about 2.7 GPa. For example, US20070129784A1 describes a stent made from a shape memory polymer having cross-linked polymer. The polymer can be either a thermoplastic polymer network or a polymer blend exhibiting shape memory characteristics. However, polymer networks have very undesirable mechanical properties, for example, low elastic moduli in the range of 0.5-50 MPa, and show stress relaxation behavior, i.e., gradually decreasing stress with time at a given temperature and strain rate. In order to reduce the effect of such shortcomings, polymeric stents are typically made to have walls that are much thicker than those of metallic ones. This not only leads to non-compact dimensions of the stents but also renders them unable to provide a biodegradation rate compatible with the duration of healing of a vascular lesion where the stent is deployed. [0013] Therefore, the conventional cross-linked polymers cannot meet the requirements for use as materials for developing medical devices in terms of mechanical properties, biocompatibility and controlled biodegradation. In addition, the complexity and excessive use of solvents in their synthesis have imposed a great challenge for controlled mass production. There is thus a need for novel cross-linked biodegradable polymers and methods of manufacturing them. Further, there is also a need for biodegradable vascular stents having sufficient mechanical strength, high elastic moduli at body temperature, compact sizes, sufficient radial strength for supporting blood vessels, minimal compression in blood vessels, stable performance, high resistance to gripping pressure, adequate shelf-lives and capability of providing a biodegradation rate compatible with the duration of healing of the vascular lesion. SUMMARY OF THE INVENTION [0014] In order to overcome the above described shortcomings of the prior art, the present invention provides novel cross-linked biodegradable polymers, vascular stents, and method of manufacturing them. [0015] Specifically, the present invention provides a biodegradable cross-linked polymer which is obtained by bonding crosslinkable reactive groups to terminal groups of biodegradable prepolymer having two or more arms and then subjecting the prepolymer to thermal polymerization and/or light irridation. The cross-linked biodegradable polymer may have an elastic modulus of from 10 MPa to 4,500 MPa and a biodegradation rate of from 3 months to 36 months. [0016] According to the present invention, the biodegradable prepolymer having two Or more arms may be selected from: n-arm-poly(L-lactide), n-arm-poly(L-lactide-co-glycolide), n-arm-poly(L-lactide-co-D-lactide), n-arm-poly(L-lactide-co-DL-lactide), n-arm-poly(L-lactide-co-ε-caprolactone), n-arm-poly(L-lactide-co-trimethyl carbonate), n-arm-poly(DL-lactide), n-arm-poly(DL-lactide-co-glycolide), n-arm-poly(DL-lactide-co-ε-caprolactone), n-arm-poly(DL-lactide-co-trimethyl carbonate), n-arm-poly(ε-caprolactone), n-arm-poly(ε-caprolactone-co-glycolide) and n-arm-poly(ε-caprolactone-co-trimethyl carbonate), wherein n=2, 3 or 4, and if the biodegradable prepolymer is a copolymer, the second comonomer is present in an amount of from 1% to 80%. [0017] According to the present invention, each of the terminal groups on the arms of the prepolymer may be selected from hydroxyl group, amino group or carboxyl group, and preferably hydroxyl group. [0018] According to the present invention, the crosslinkable reactive groups are bonded to the terminal groups of the prepolymer through the reaction of the prepolymer and an acrylate or methacrylate containing functional groups including, but not limited to, acid anhydride, acid, acyl chloride, isocyanate and propylene oxide groups, such as, for example, methacrylic anhydride, 2-isocyanatoethyl methacrylate, epoxypropyl methacrylate, etc. [0019] According to the present invention, the prepolymer having the two or more (n) arms may be formed by adding an initiator containing two or more (n) hydroxyl groups to a monomer. [0020] According to the present invention, the initiator may be an initiator having two hydroxyl groups, preferably ethylene glycol, 1,4-butylene glycol, n-decanediol, tripropylene glycol, triethylene glycol, triethylene glycol dimethacrylate, triethylene glycol dimethyl ether, triethylene glycol mono-11-mercaptoundecyl ether, triethylene glycol monobutyl ether, triethylene glycol methyl ether methacrylate, polyethylene glycol (PEG) having a molecular weight of 100-10,000, poly(tetrahydrofuran)glycol (polyTHF) having a molecular weight of 100-10,000 or poly(ε-caprolactone)glycol (PCL) having a molecular weight of 100-10,000; an initiator having three hydroxyl groups, including but not limited to, polycaprolactone triol (having a molecular weight of 300 or 900), trihydroxy polyoxypropylene ether, 1,2,3-heptanetriol, 1,2,6-hexanetriol, trimethylolpropane and 3-methyl-1,3,5-pentanetriol; or an initiator having four hydroxyl groups, such as 1,2,7,8-octanetetrol, propoxylated pentaerythritol, dipentaerythritol and pentaerythritol. [0021] The present invention also provides a method of preparing the said cross-linked polymer. The method includes: (1) synthesis of a biodegradable polymeric prepolymer having two or more (n) arms from a cyclic monomer and an initiator in the presence of a catalyst by ring-opening polymerization; (2) formation of a crosslinkable polymeric prepolymer by bonding crosslinkable reactive groups to terminal groups of the biodegradable polymeric prepolymer through reaction of the terminal groups with, for example, methacrylic anhydride or 2-isocyanatoethyl methacrylate; and (3) crosslinking of the prepolymer by thermal polymerization and/or light irradiation and formation of a cross-linked polymer. [0025] According to the present invention, the prepolymer may have a molecular weight of from 2,000 to 100,000, preferably from 5,000 to 50,000. [0026] According to the present invention, the crosslinking may be induced by thermal polymerization and/or light irradiation performed during or after a molding process. [0027] According to the present invention, the catalyst may be stannous-2-ethylhexanote present in an amount of from 0.01% to 0.1%, with from 0.01% to 0.5% being more preferred. [0028] The present invention discloses a method for synthesizing a biodegradable prepolymer by ring-opening polymerization. The prepolymer may have a linear or star-shaped architecture and have two or more hydroxyl, amino or carboxyl group, notably hydroxyl group, on terminals of each of its molecules. When the molecular weight of prepolymer reach a designed weight, methacrylic anhydride or 2-isocyanatoethyl methacrylate and a free radical inhibitor are added, so that the reactive group containing C═C double bond are directly bonded to the terminals of the prepolymer. After the reaction, the crosslinkable, biodegradable prepolymer obtained in a melt state may be pulverized and pelletized for further use. The whole process is simple, continuous and does not involve the use of any solvent and allows a reactor to produce several or even more than ten kilograms of the crosslinkable prepolymer. The synthesis may be performed in an even larger scale depending on the volume of the reactor. The pulverized and pelletized crosslinkable prepolymer can be formed into tubes, rods or other shapes by injection, extrusion or other molding process. In addition, crosslinking of the prepolymer may be carried out by UV light irradiation, thermal polymerization or the like during or after the molding and a biodegradable cross-linked polymer can be thereby formed. [0029] In the molding according to the present invention, a transparent glass mold designed to form a tube may be used. The mold may include an inner core rod (column) and an outer cylinder with a larger diameter. A wall thickness of the tube to be formed is determined by diameters of the inner core rod and outer cylinder. The melt-state crosslinkable prepolymer may be injected into a space between the inner core rod and outer cylinder and then subjected to UV light or heat, such that when the inner core rod and outer cylinder are separated, a cross-linked polymer tube is obtained. [0030] Alternatively, the molding according to the present invention may be an extrusion molding process in which the crosslinkable prepolymer may be extruded by an extruder onto a polyethylene rod, during which the rod may be simultaneously fed out from the extruder in order to ensure shape integrity of the crosslinkable tube being formed. The crosslinkable tube may receive a preliminary crosslinking treatment while it is pulling out from an outlet of the extruder and then a further crosslinking treatment after the completion of the extrusion. Afterward, with the polyethylene rod removed, a cross-linked polymer tube can also be obtained. [0031] Cross-linked biodegradable polymers according to the present invention may have an elastic modulus of from 10 MPa to 4,500 MPa and a biodegradation rate of from 3 months to 36 months. In addition, these properties can be designed and adjusted depending on the usage of the polymer, by suitably choosing the initiator, monomer and comonomers. [0032] The cross-linked biodegradable polymer according to the present invention differs from conventional cross-linked biodegradable polymers in terms of synthesis, composition and properties. The cross-linked biodegradable polymer according to the present invention is excellent in mechanical properties, highly compatible with tissues and blood and biodegradable at a rate that is adjustable depending on specific needs. [0033] The present invention further provides a biodegradable vascular stent produced by laser cutting a polymeric tube, characterized in that the polymeric tube is formed from a three-dimensional cross-linked polymer network, i.e., a cross-linked polymer. [0034] According to the present invention, the formation of the polymeric tube may include the steps of: [0035] preparing a prepolymer, wherein the prepolymer may be a biodegradable polymer selected from the group consisting of poly(L-lactide) (L-PLA), poly(DL-lactide) (DL-PLA), poly(glycolic acid) (PGA), poly(ε-caprolactone) (PCL), poly(trimethylene carbonate) (PTMC), poly(p-dioxanone) (PPDO), amino acid-derived polycarbonates (PDTE) and polyorthoesters (POE); or a blend of any two of the above biodegradable polymers, including but not limited to, a blend of L-PLA and PCL and a blend of DL-PLA and PCL in which PCL functions to improve brittleness of the polylactides and adjust the biodegradation rate; or a copolymer of one of the above biodegradable polymers as a monomer and a second monomer present in a small amount, and wherein the prepolymer has a molecular weight of from 5,000 to 1,200,000 (first prepolymer) and an intrinsic viscosity of from 0.1 to 9.0 dl/g; and [0036] molding the prepolymer into a tube and performing a crosslinking process on the tube to obtain the said polymeric tube. [0037] According to the present invention, the crosslinking process may include any of: (1) bonding crosslinkable reactive groups to terminal groups of the prepolymer and inducing crosslinking of the crosslinkable reactive groups during or after the molding; and (2) in case of the terminal groups of the prepolymer being selected from the group consisting of hydroxyl, carboxyl, amino and epoxy groups, adding a crosslinking agent to induce a crosslinking reaction before or during the molding. [0040] According to the present invention, the tube may be formed by extrusion molding or injection molding. [0041] According to the present invention, the crosslinkable reactive groups may be bonded to the terminal groups of the prepolymer by means of an acrylate containing double bonds. The acrylate containing double bonds may be, for example, but not limited to, methacrylic acid, methacryloyl chloride, methacrylic anhydride, 2-isocyanatoethyl methacrylate, epoxypropyl methacrylate or cinnamoyl chloride. [0042] According to the present invention, the crosslinking agent may have two or more functional groups and may be linear or star-shaped crosslinking agents containing isocyanate or epoxy group. The crosslinking agent may have a number-average molecular weight of from 500 to 100,000. [0043] According to the present invention, the second monomer may be selected from the group consisting of D-lactide, DL-lactide, glycolide, ε-caprolactone and trimethyl carbonate. In addition, in order to impart to the stent a fine biodegradation rate compatible with the duration of healing of the vascular lesion, the amount of the second monomer may be adjusted in a range of 1-50 mol %, preferably 1-15 mol %, during the preparation of the prepolymer. [0044] According to the present invention, the tube may have an outside diameter of from 2 mm to 10 mm and a wall thickness of from 50 μm to 250 μm. [0045] The present invention further provides a method of manufacturing a biodegradable vascular stent. The method includes: [0046] preparing a prepolymer, wherein the prepolymer may be a biodegradable polymer selected from the group consisting of L-PLA, DL-PLA, PGA, PCL, PTMC, PPDO, PDTE and POE; or a blend of any two of the above biodegradable polymers, including but not limited to, a blend of L-PLA and PCL and a blend of DL-PLA and PCL in which PCL functions to improve brittleness of the polylactides and adjust the biodegradation rate; or a copolymer of one of the above biodegradable polymers as a monomer and a second monomer present in a small amount, and wherein the prepolymer has a molecular weight of from 5,000 to 1,200,000 and an intrinsic viscosity of from 0.1 to 9.0 dl/g; [0047] molding the prepolymer into a tube and performing a crosslinking process on the tube to obtain the said polymeric tube; and [0048] laser cutting the tube into the biodegradable vascular stent. [0049] A blending or copolymerization ratio of the biodegradable polymers may be adjustable according to the requirements for strength, deformation and biodegradation rate of the stent. In case of blending or copolymerization of two polymers, the ratio may be from 1:1 to 1:20, preferably from 1:5 to 1:20. [0050] The materials for forming the biodegradable vascular stent may be blended using methods, including but not limited to, solvent blending and melt blending. As used herein, “solvent blending” refers to a process in which two or more polymers are dissolved and mixed together in an organic solvent, while “melt blending” refers to a process in which two or more polymers are melted and mixed together at a high temperature. [0051] The materials for forming the biodegradable vascular stent may be copolymerized using methods, including but not limited to, graft copolymerization, block copolymerization and random copolymerization. Monomers suitable for these three copolymerization methods are two or more selected from, but not limited to, L-lactic acid, D-lactic acid, hydroxyacetic acid (glycolic acid), ε-caprolactones, salicylic acid, carbonates, amino acids and their derivatives. [0052] When preparing the prepolymer having a linear or star-shaped architecture, an initiator and a catalyst may be introduced. The initiator having two hydroxyl groups used for forming a linear prepolymer, or the initiator having three or four hydroxyl groups used for forming a star-shaped prepolymer. The initiator may be selected from, but not limited to, initiators having two hydroxyl groups, such as ethylene glycol, 1,4-butylene glycol, n-decanediol, tripropylene glycol, triethylene glycol, triethylene glycol dimethacrylate, triethylene glycol dimethyl ether, triethylene glycol mono-11-mercaptoundecyl ether, triethylene glycol monobutyl ether, triethylene glycol methyl ether methacrylate, polyethylene glycol (PEG) having a molecular weight of 100-10,000, poly(tetrahydrofuran)glycol (pTHF) having a molecular weight of 100-10,000 and poly-caprolactone glycol (PCL) having a molecular weight of 100-10,000, initiators having three hydroxyl groups, such as polycaprolactone triol (having a molecular weight of 300 or 900), trihydroxy polyoxypropylene ether, 1,2,3-heptanetriol, 1,2,6-hexanetriol, trimethylolpropane and 3-methyl-1,3,5-pentanetriol, and initiators having four hydroxyl groups, such as pentaerythritol, 1,2,7,8-octanetetrol, propoxylated pentaerythritol and dipentaerythritol. The catalyst may be selected from, but not limited to, stannous-2-ethylhexanote and dibutyltin dilaurate. The catalyst may be present in an amount of 0.01-0.1%, preferably 0.01-0.5%. [0053] The number-average molecular weight of the prepolymer based on polylactic may be controlled in a range of from 5,000 to 100,000, preferably in a range of from 5,000 to 50,000, through adjusting a ratio of an amount of the initiator or a ratio of an amount of the second comonomer. [0054] A biodegradation rate of the biodegradable material made of the biodegradable prepolymer is determined by a ratio of the first comonomer to the second comonomer. [0055] The biodegradation may be tested using a shaker equipped with a water bath kept at a constant temperature of 37° C. In the test, a sample of the material with given dimensions and weight is submersed in a buffer solution having a pH of 7 in the water bath. At intervals, the sample is taken out, dried and weighed to calculate its weight loss percentages (wt %). [0056] In case of the crosslinking agent being used, the unit or the number-average molecular weight of the prepolymer acting a first prepolymer may be the same or not as a second prepolymer used for the crosslinking agent. And the number-average molecular weight of the second prepolymer is smaller than that of the first prepolymer. The terminal groups of the first prepolymer may be, but not limited to, hydroxyl groups. The number of the arms of the first prepolymer may be determined by the number of reactive groups, for example, hydroxyl groups, of the initiator used in its synthesis, and may be usually 2, 3, or 4. The first prepolymer may have a number-average molecular weight of from 5,000 to 1,200,000 and an intrinsic viscosity of from 0.1 to 9.0 dl/g. Alternatively, the first prepolymer may also be provided as a merchandised product. [0057] In some embodiments, the prepolymer is made from L-lactide and a second monomer. The second monomer may be one or two selected from the group consisting of D-lactide, racemic lactide, glycolide, ε-caprolactone and trimethyl carbonate. The biodegradation time of the biodegradable vascular stent made from the prepolymer is determined by the ratio of L-lactide to the second monomer, compatible with the duration of healing of a vascular lesion. The molar percentage of the second monomer may be 1-25%, preferably 1-15%. The second monomer may be one or two selected from the group consisting of D-lactides, racemic lactides, glycolides, ε-caprolactones and trimethyl carbonates. [0058] The polymeric tube may be added with a drug during its formation such that the drug is distributed uniformly in the tube that acts as a carrier for the drug. A drug-containing biodegradable stent may be further obtained by laser cutting this polymeric tube. Alternatively, the polymeric tube may be cut into a biodegradable stent ( FIGS. 3( a )- 3 ( g )) by laser firstly and the stent is then coated with the drug on its surface. Each of these two approaches enables the drug coated on the surface of or contained within the biodegradable stent to be released in a desired sustained manner to the wall of a target vessel where the stent is deployed, thus inhibiting intimal hyperplasia and reducing the incidence of restenosis. [0059] The drug may be one or more selected from the group consisting of anticancer agents, anticoagulants, microbial immunosuppressive agents and other anti-restenosis agents. [0060] The anticancer agents may be one or more selected from methotrexate, purines, pyrimidines, plant alkaloids, epothilones, triptolide compounds, antibiotics (notably actinomycin D), hormones and antibodies. Preferably, the anticancer agents choose from paclitaxel. [0061] The anticoagulants may be one or more selected from heparin, aspirin, hirudin, colchicine and platelet GPIIb/IIIa receptor antagonists. The platelet GPIIb/IIIa receptor antagonists may be one or more selected from tirofiban, abciximab and eptifibatide. [0062] The microbial immunosuppressive agents may be one or more selected from cyclosporin A, tacrolimus and its analogues, despergualin, mycophenolate esters, rapamycin and its derivatives, FR-900520 substance from Streptomyces strains, FR-900523 substance from Streptomyces strains, daclizumab, pentanamide, kanglemycin C, spergualin, prodigiosin-25C, tranilast, myriocin, cyclosporin C, bredinin, mycophenolic acid, brefeldin A and ketosteroids. [0063] The other anti-restenosis agents may be one or more selected from batimastat, metalloproteinase inhibitors, 17β-estradiol, NO donors, 2-chlorodeoxyadenosine, 2-deoxycoformycin, fingolimod, mycophenolate sodium, ISA TX 247 (a cyclosporin A derivative), elsibucol, daclizumab, basiliximab, anti-thymocyte globulin, everolimus, methotrexate, neoral, cyclophosphamide, brequinar sodium, leflunomide and mizoribine. [0064] Radiopacity may be imparted to the biodegradable stent either by embedding a radiopaque material such as a metallic material, for example, gold, in a terminal portion of the stent or by adding the radiopaque material to the polymeric tube during its formation. The radiopaque material may be selected from, but not limited to: biodegradable metallic materials, such as magnesium alloys; iodides, such as 6-triiodobenzoic acid, sodium 6-triiodobenzoate, iothalamic acid, metrizoic acid, iodamide, ioxaglic acid, iopamide, iohexol and iotrolan; bismuth compounds, such as bismuth oxide; barium sulfate; metal powders, such as tantalum and gold powders; other common radiopaque material; and mixtures of two or more of the above. Preferably, the radiopaque material is an iodide, a gold powder, a platinum powder, a tantalum powder, a titanium powder, a tungsten powder, or barium sulfate. The radiopaque material enables radiological imaging of the stent which helps in navigating the stent to an implantation site during the implantation and in observing whether there is a displacement of the stent after the implantation. [0065] Biodegradable vascular stents according to the present invention are formed by laser cutting polymeric tubes which have three-dimensional cross-linked network structures and elastic moduli of from 2.5 GPa to 4.5 GPa at the room temperature and most of which have elastic moduli of up to 3 GPa even at the body temperature of 37° C. Such high mechanical strength, coupled with the three-dimensional cross-linked network structures, imparts to the stents sufficient radial compression resistance and a maximum extent of reduction in mechanical relaxation behavior, thereby reducing stent retraction. Further, the introduction of a small amount of the second monomer enables effective control of the stent biodegradation rate according to the duration of healing of the vascular lesion and makes the stents able to be biodegraded and absorbed in 1-3 years. BRIEF DESCRIPTION OF THE DRAWINGS [0066] Features of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings. It is apparent that what are presented in the drawings are merely a few non-limiting specific embodiments of biodegradable prepolymers, cross-linked polymers and vascular stents described in this application. [0067] FIG. 1( a ) shows synthesis of a 3-arm-star-shaped prepolymer with hydroxyl groups at its terminals, wherein x=3-300, and y=1-100. [0068] FIG. 1( b ) shows formation of a crosslinkable 3-arm-star-shaped prepolymer having crosslinkable reactive groups by bonding the crosslinkable reactive groups to the terminal hydroxyl groups of the 3-arm-star-shaped prepolymer. [0069] FIGS. 2( a ) to 2 ( c ) show a process of making a polymeric tube having a three-dimensional cross-linked network structure in accordance with embodiments of the present invention, wherein [0070] FIG. 2( a ) shows synthesis of a prepolymer having terminal hydroxyl group; [0071] FIG. 2( b ) shows synthesis of a crosslinking agent by bonding isocyanate group to terminal groups of another prepolymer; and [0072] FIG. 2( c ) shows formation of a tube from a blend blended adequately by the prepolymer having terminal hydroxyl group and the crosslinking agent having terminal isocyanate group. [0073] FIGS. 3( a ) to 3 ( g ) show examples of biodegradable vascular stents having different structures according to embodiments of the present invention. DETAILED DESCRIPTION [0074] For a better understanding of the present invention, its preferred features are described in the following Examples. The description is provided merely for illustrating the features and advantages of the present invention rather than limiting its scope. EXAMPLE 1 Synthesis of Degradable Polymers Having Two or More Hydroxyl Groups [0075] (1a) the degradable polymers according to the present invention refers to, but not limited to, the following polymers, formed by melt ring-opening polymerization and having n arms/terminal groups, where n is determined by the number of arms of an initiator used in the polymerization and is ≧2, preferably 2, 3 or 4: [0076] n-arm-poly(L-lactide), where n=2, 3 or 4, [0077] n-arm-poly(L-lactide-co-glycolide), where n=2, 3 or 4, [0078] n-arm-poly(L-lactide-co-D-lactide), where n=2, 3 or 4, [0079] n-arm-poly(L-lactide-co-DL-lactide), where n=2, 3 or 4, [0080] n-arm-poly(L-lactide-co-ε-caprolactone), where n=2, 3 or 4, and [0081] n-arm-poly(L-lactide-co-trimethyl carbonate), where n=2, 3 or 4, [0082] wherein each second comonomer is present in an amount of 1-80%; [0083] n-arm-poly(DL-lactide), where n=2, 3 or 4, [0084] n-arm-poly(DL-lactide-co-glycolide), where n=2, 3 or 4, [0085] n-arm-poly(DL-lactide-co-ε-caprolactone), where n=2, 3 or 4, and [0086] n-arm-poly(DL-lactide-co-trimethyl carbonate), where n=2, 3 or 4, [0087] wherein each second comonomer is present in an amount of 1-80%; [0088] n-arm-poly(ε-caprolactone), where n=2, 3 or 4, [0089] n-arm-poly(ε-caprolactone-co-glycolide), where n=2, 3 or 4, and [0090] n-arm-poly(ε-caprolactone-co-trimethyl carbonate), where n=2, 3 or 4, [0091] wherein each second comonomer is present in an amount of 1-80%. [0092] (1b) an initiator having 2, 3 or 4 hydroxyl groups was used for each of the said biodegradable polymers, and selected from, but not limited to: [0093] initiators having two hydroxyl groups selected from: [0094] ethylene glycol, 1,4-butylene glycol, n-decanediol, tripropylene glycol, triethylene glycol, triethylene glycol dimethacrylate, triethylene glycol dimethyl ether, triethylene glycol mono-11-mercaptoundecyl ether, triethylene glycol monobutyl ether, triethylene glycol methyl ether methacrylate, polyethylene glycol (PEG) having a molecular weight of 100-10,000, poly(tetrahydrofuran)glycol (polyTHF) having a molecular weight of 100-10,000 and poly(ε-caprolactone)glycol (PCL) having a molecular weight of 100-10,000, wherein biodegradable linear polymeric prepolymer prepared have two terminal hydroxyl groups, wherein in case of PEG, polyTHF, or PCL selected as the initiator, the biodegradable linear polymer is a PLA-PEG-PLA, PLA-polyTHF-PLA, or PLA-PCL-PLA three-block copolymer with improved hydrophilicity, biodegradation rate and mechanical properties; [0095] initiators having three hydroxyl groups selected from: [0096] polycaprolactone triol (having a molecular weight of 300 or 900), trihydroxy polyoxypropylene ether, 1,2,3-heptanetriol, 1,2,6-hexanetriol, trimethylolpropane and 3-methyl-1,3,5-pentanetriol, wherein a star-shaped polymer prepared have three terminal hydroxyl groups; [0097] initiators having four hydroxyl groups selected from: [0098] 1,2,7,8-octanetetrol, propoxylated pentaerythritol, dipentaerythritol and pentaerythritol, wherein a star-shaped polymer prepared have four terminal hydroxyl groups. [0099] (1c) the biodegradable prepolymers had a molecular weight of from 2,000 to 100,000, preferably from 5,000 to 50,000. [0100] (1d) in the synthesis of each of the biodegradable prepolymer, stannous-2-ethylhexanote (CAS: 301-10-0) was used in an amount of from 0.01% to 0.1%, preferably from 0.01% to 0.5%. EXAMPLE 2 Functionalization of (i.e., Addition of Crosslinkable Groups To) Linear or Star-Shaped Prepolymer Containing Hydroxyl Groups [0101] Upon the molecular weight of a biodegradable prepolymer having two or more hydroxyl groups reaching a desired value, there were added in the reactor a free radical inhibitor, for example, but not limited to, 4-methoxyphenol (with an amount of 0.01 wt %-1.0 wt %), and a calculated amount of methacrylic anhydride or 2-isocyanatoethyl methacrylate. As a result, crosslinkable acticve group containing unsaturated double bond were bonded to the terminal groups of the prepolymer and a crosslinkable polymeric polymer was obtained. EXAMPLE 3 Synthesis and Functionalization of 3-Arm-Star-Shaped Copolymeric Prepolymer Based on Polylactic Acid [0102] Prior to the synthesis, a 3L reactor was dried in vacuum at 80° C. for one hour. 2000 g L-lactide, 100 g glycolide and 14 g 1,2,6-hexanetriol were then added in the reactor under the protection of nitrogen gas and dried in vacuum at 60° C. for one hour. Thereafter, 2 g stannous-2-ethylhexanote was further added and the temperature was increased to 140° C. and maintained at 140° C. for 3 hours, forming a star-shaped copolymeric prepolymer based on polylactic acid having a number-average molecular weight of 20,000 (Equation 1). [0103] The molecular weight of the star-shaped copolymeric prepolymer was determined by a ratio of an amount of the initiator or a ratio of an amount of the monomers and its number-average molecular weight might be controlled in a range of from 5,000 to 50,000. Upon the molecular weight of the star-shaped polylactic acid copolymeric prepolymer reaching a designed value, 48 g (0.32 mol) of methacrylic anhydride and 0.6 g (300 ppm) of 4-methoxyphenol were directly added in drops and the system was then maintained at 150° C. for 2 hours to form a crosslinkable star-shaped polymer (Equation 2). With the completion of the reaction, the reactor was cooled down to 60° C. and 5 L of ethyl acetate was added therein to dissolve the prepolymer. The solution was then slowly poured into a mixture of hexane and ethanol and a product was obtained after a precipitate in the solution was dried. [0000] [0104] For the sake of clarity, the biodegradable prepolymer having three hydroxyl groups (n=3) in the Equation is represented hereinafter briefly as: [0000] [0000] EXAMPLE 4 Synthesis and Functionalization of 2-Arm-Linear Prepolymer Based on Polylactic Acid [0105] Prior to the synthesis, a 3L reactor was dried in vacuum at 60° C. for one hour. 2000 g L-lactide and 50 g Poly(THF) were then added in the reactor under the protection of nitrogen gas and dried in vacuum at 60° C. for one hour. Thereafter, 2 g stannous-2-ethylhexanote was further added and the temperature was increased to 140° C. and maintained for 3 hours, forming a linear prepolymer based on polylactic acid having a number-average molecular weight of 20,000. The molecular weight of the linear prepolymer was determined by a ratio of an amount of the initiator or a ratio of an amount of the monomer and its number-average molecular weight might be controlled in a range of from 5,000 to 50,000. Upon the molecular weight of the linear prepolymer reaching a designed value, 2-isocyanatoethyl methacrylate and 300 ppm of 4-methoxyphenol were added to form a crosslinkable linear polymer (Equation 3). [0000] EXAMPLE 5 Synthesis and Functionalization of 4-Arm-Star-Shaped Prepolymer Based on Polylactic Acid [0106] Prior to the synthesis, a 3L reactor was dried in vacuum at 60° C. for one hour. 2000 g L-lactide, 100 g ε-caprolactone and 60 g pentaerythritol were then added in the reactor under the protection of nitrogen gas and dried in vacuum at 60° C. for one hour. Thereafter, 2 g stannous-2-ethylhexanote was further added and the temperature was increased to 140° C. and maintained for 3 hours, forming a star-shaped prepolymer having a number-average molecular weight of 18,000. The molecular weight of the star-shaped prepolymer was determined by a ratio of an amount of the initiator or a ratio of an amount of the monomers and its number-average molecular weight might be controlled in a range of from 5,000 to 50,000. Upon the molecular weight of the star-shaped copolymeric prepolymer reaching a designed value, 72 g methacrylic anhydride and 0.6 g (300 ppm) of 4-methoxyphenol were directly added and the system was then maintained to form a crosslinkable star-shaped polymer (Equation 4). With the completion of the reaction, the reactor was cooled down to 60° C. and 5 L of ethyl acetate was added therein to dissolve the prepolymer. The solution was then slowly poured into a mixture of hexane and ethanol and a product was obtained after a precipitate in the solution was dried. [0000] [0107] where, [0000] [0000] represents the biodegradable polymer having 4 hydroxyl groups (n=4). [0108] In summary, various polymers with different molecular weights can be obtained through ring-opening polymerization of different monomers or comonomers in presence of initiators differing in terms of type, number of arms, etc. While many other biodegradable materials with different properties can be further prepared using the methods described above, their preparation is not exemplified herein. EXAMPLE 6 Crosslinking of Polymers [0109] Each of the above-described prepared linear and star-shaped polymeric prepolymers was adequately blended with a photoinitiator such as, but not limited to, Esacure KIP 150 (with an amount of 0.1 wt %-0.5 wt %) and then melted by heat within a space between two glass blocks. In the space, PTFE film frame were arranged to adjust a thickness of the plate being formed to a desired value. Afterward, crosslinking of the melt blended was induced by UV light irradiation, thereby obtaining a standard model. The mechanical and thermal properties of the sample presented in Table 1. [0110] In addition, biodegradation of the model was tested using a shaker equipped with a water bath kept at a constant temperature of 37° C. A sample of the formed model with given dimensions and weight was submersed in a buffer solution (pH 7) in the water bath. At intervals, the sample was taken out, dried and weighed to calculate its weight loss percentages (wt %) [0000] TABLE 1 Mechanical and Thermal Properties of Cross-linked Biodegradable Polymers Mechanical properties Biodegradation Room temperature Body temperature rate: weight (23° C.) (37° C.) loss Elastic Elongation Elastic Elongation Thermal percentage modulus at break modulus at break property (wt %) at the Cross-linked polymers (Gpa) (%) (Gpa) (%) (Tg/° C.) 52 nd week PLGA (95/5) 4.3 3 3.3 40 58 20% PLGA (90/10) 4.0 3 3.2 75 58 35% PLGA (85/15) 3.0 76 1.7 45 55 60% PLGA (85/15)-pTHF250 3.6 18 3.0 134 50 70% PLGA (85/15)-PCL500 3.4 3 1.8 140 44 60% P(L-LA70-DL-LA30)-TERA 3.1 125 0.9 146 42 15% PLGA (85/15)-PEG400 2.5 47 40 75% PLGA (85/15)-PEG600 0.7 150 29 80% PLGA (85/15)-PEG1000 0.31 220 20 92% PLGA (85/15)-PCL540 0.12 200 24 53% PLGA (85/15)-PCL triol900 0.96 160 36 ND P(DL-LA/ε-CL 2.2 145 35 ND 90/10)-PCL540 PLGA (85/15)-PC500 3.4 3 1.8 140 44 55% [0111] In this table: [0112] PLGA represents poly(L-lactide-co-glycolide), wherein PLGA (95/5) indicates a poly(L-lactide-co-glycolide) with a ratio of its L-lactide content to glycolide content of 95:5, and the same is applied to all the others; [0113] PLLA represents a poly(L-lactide); [0114] PDLLA represents a poly(DL-lactide); [0115] P(L-LA70-DL-LA30)-TERA represents a poly(L-lactide-co-DL-lactide) having a ratio of its L-lactide content to DL-lactide content of 70:30, formed using pentaerythritol as the initiator; [0116] pTHF250 represents a poly(tetramethylene ether)glycol with a molecular weight of 250; [0117] PCL represents poly(ε-caprolactone)glycols, wherein PCL500 and PCL540 indicate poly(ε-caprolactone)glycols with molecular weights of 500 and 540, respectively; [0118] PEG400, PEG600 and PEG1000 represent polyethylene glycols with molecular weights of 400, 600 and 1000, respectively; [0119] PLGA(85/15)-PCL triol900 represents a poly(L-lactide-co-glycolide) having a ratio of its L-lactide content to glycolide content of 85:15, formed using a polycaprolactone triol with a molecular weight of 900 as the initiator; [0120] P(DL-LA/ε-CL 90/10)-PCL540 represents a poly(DL-lactide-co-ε-caprolactone) having a ratio of its DL-lactide content to ε-caprolactone content of 90:10, formed using a polycaprolactone triol with a molecular weight of 540 as the initiator; [0121] PLGA(85/15)-PC500 represents a poly(L-lactide-co-glycolide) having a ratio of its L-lactide content to glycolide content of 85:15, formed using a polycarbonate diol with a molecular weight of 500 as the initiator; and [0122] ND is brief for “not determined”. [0123] It can be seen from the weight loss percentages at the 52 nd week of the samples shown in Table 1, polymers with higher glycolide contents have increased biodegradation rates. Biodegradation rates of the polymers can be adjusted by using different initiators. For example, using a poly(tetramethylene ether)glycol as the initiator will lead to an increase in biodegradation rate because of its high hydrophilicity. [0124] From the data in Table 1, it can also be found that, the biodegradable cross-linked polymers have elastic moduli ranging from 0.12 GPa to 4 GPa depending on their compositions, and at the body temperature, some of them maintain high elastic moduli and show improved elongations at break. That is, such polymers are tough but not brittle. Thermal properties (glass transition temperatures) of the polymers range from 20° C. to 60° C. Biodegradation rates of these polymers can be adjusted to a range of from 3 months to 36 months. Further, other parameters may also be adjusted and diversified to satisfy more practical needs. EXAMPLE 7 Formation and Crosslinking of Polymeric Tube [0125] Each of the above-described prepared crosslinkable prepolymers was sufficiently blended with the photoinitiator Esacure KIP 150 (with an amount of 0.3 wt %) and then dried in a vacuum oven. The dried blend was extruded to form a tube or rod by a twin-screw extruder. During the extrusion, the tube or rod being formed were irradiated with UV light or other radiation to achieve rapid crosslinking. [0126] In addition, this rapid crosslinking during the extrusion might be conducted as a preliminary polymerization process. In order to increase the stability of the tube or rod, the tube or rod was further heated at a temperature lower than a glass transition temperature of the polymer, preferably 5° C. lower than the latter, and then irradiated by UV light again until the gel content of the polymer exceeded 95%. [0127] Crosslinking of the tube or rod might be further enhanced to a higher extent if desired. EXAMPLE 8 Polymeric Tubes with Cross-Linked Network Structure [0128] Biodegradable vascular stents according to the present invention were formed by laser cutting respective polymeric tubes each having a three-dimensional cross-linked network structure. The formation of the polymeric tubes is described below with reference to the following sub-examples. EXAMPLE A Prepolymer Self-Crosslinking [0129] Synthesis of Star-Shaped Copolymeric Prepolymer Based on Polylactic Acid and Addition of Crosslinkable Groups Thereto [0130] Referring to FIG. 1( a ), prior to the synthesis, a 3L glass reactor was dried in vacuum at 80° C. for one hour, and 2100 g L-lactide, 370 g glycolide and 22 g (0.16 mol) 1,2,6-hexanetriol were then added in the reactor. After the reactor was deoxygenated by repeating the process of evacuation and argon filling, stannous-2-ethylhexanote was added therein and the reaction was run at 145° C. Upon a number-average molecular weight of the star-shaped copolymeric prepolymer reaching a designed value, 114 g (0.741 mol) methacrylic anhydride and 0.75 g free radical inhibitor such as, for example, 4-methoxyphenol, to prepare a crosslinkable star-shaped prepolymer ( FIG. 1( b )). With the completion of the reaction, the reactor was cooled down to 60° C. and 5 L of ethyl acetate was added therein to dissolve the prepolymer. The solution was then slowly poured into a mixture of hexane and ethanol and a product was obtained after a precipitate in the solution was dried. [0131] The crosslinkable star-shaped polymer might be formed into a tube by means of extrusion, injection, or other forming technique. During or after the formation, crosslinking of the crosslinkable star-shaped polymer might be induced by UV light irradiation to form a polymeric tube with a three-dimensional cross-linked network structure. Their mechanical properties are provided in Table 2. [0132] Biodegradation rates of synthesized biodegradable materials were tested by a shaker at a constant temperature and indicated by their weight loss percentages, such as the data of weight loss percentages at the 52 nd week shown in Table 2, from which it can also be found that, polymers with higher glycolide contents have increased biodegradation rates. Biodegradation rates of the polymers can be adjusted by using different initiators. For example, using a poly(tetramethylene ether)glycol as the initiator will lead to an increase in biodegradation rate because of its high hydrophilicity. [0000] TABLE 2 Mechanical Properties of Cross-linked Polymers Biodegradation Rate (in vitro Mechanical properties biodegradation): Room temperature Body temperature weight (23° C.) (37° C.) loss Elastic Elongation Elastic Elongation Thermal percentage modulus at break modulus at break property (%) at the Cross-linked polymers (Gpa) (%) (Gpa) (%) (Tg/° C.) 52 th week PLGA (95/5) 4.3 3 3.3 40 58 20% PLGA (90/10) 4.0 3 3.2 75 58 35% PLGA (85/15) 3.0 76 1.7 45 55 60% PLGA (85/15)-pTHF250 3.6 18 3.0 134 50 70% PLGA (85/15)-PCL500 3.4 3 1.8 140 44 60% P(L-LA70-DL-LA30)-PC 3.1 125 0.9 146 42 15% L540 [0133] In this table: [0134] PLGA represents a poly(L-lactide-co-glycolide), wherein PLGA (95/5) indicates a poly(L-lactide-co-glycolide) with a ratio of its L-lactide content to glycolide content of 95:5, and PLGA (90/10) indicates a poly(L-lactide-co-glycolide) with a ratio of its L-lactide content to glycolide content of 90:10; [0135] PLLA represents a poly(L-lactide); [0136] PDLLA represents a poly(DL-lactide); [0137] P(L-LA70-DL-LA30) represents a poly(L-lactide-co-DL-lactide) having a ratio of its L-lactide content to DL-lactide content of 70:30; [0138] pTHF250 represents a poly(tetramethylene ether)glycol with a molecular weight of 250; and [0139] PCL represents poly(ε-caprolactone)glycols, wherein PCL500 and PCL540 indicate poly(ε-caprolactone)glycols with molecular weights of 500 and 540, respectively. [0140] From data in the above table, it can be seen that the cross-linked polymers synthesized in accordance with this sub-example possess high elastic moduli (>3 GPa) at the room temperature. Particularly some of them maintain high elastic moduli (>3 GPa) and exhibit high elasticity (evidenced by their elongation of ≧40% at break) at 37° C. It provides stents made of them with sufficient radial strength and resistance to compression. In addition, selecting suitable comonomers can enable the adjustment of the polymer's biodegradation rate according to the duration of healing of the vascular lesion. EXAMPLE B Crosslinking Between Prepolymer and Crosslinking Agent [0141] Referring to FIG. 2( a ), in a first step, a biodegradable star-shaped polymeric copolymer serving as a first prepolymer was synthesized by ring-opening polymerization from a cyclic monomer or cyclic comonomers, such as L-lactide and ε-caprolactone (molar ratio of L-LA/ε-CL: 95/5). [0142] In a second step, a crosslinking agent was synthesized, as shown in FIG. 2( b ). A hydroxyl group-containing star-shaped copolymer serving as a second prepolymer was synthesized by the same approach as in the first step. For example, the second prepolymer was made from L-lactide and ε-caprolactone (molar ratio of L-LA/ε-CL: 95/5). The second prepolymer differ from the first prepolymer obtained in the first step in the number-average molecular weight controlled within a range of from 500 to 10,000. Subsequently, isocyanate groups were boned to terminals of molecules of the second prepolymer (which might be a linear or star-shaped polymer having 2, 3 or 4 arms, preferably 3 or 4 arms which might lead to a better crosslinking effect). The prepared polymer was then precipitated and rinsed until there is no residue of the isocyanate therein, thus forming the crosslinking agent. [0143] In a third step, as shown in FIG. 2( c ), the first prepolymer prepared in the first step and the crosslinking agent with terminal isocyanate groups were blended sufficiently and optionally added with a suitable amount (0.1 mol %) of a catalyst such as dibutyltin dilaurate (CAS: 77-58-7). The blend was then formed into a tube by extrusion molding or injection molding. The formed tube may be subjected to a suitable thermal treatment to obtain an enhanced crosslinking degree, thus forming a polymeric tube with the three-dimensional cross-linked network structure. EXAMPLE 9 Stents [0144] In general terms, the polymeric tubes with three-dimensional cross-linked network structures might each have an outside diameter of 2-10 mm and a wall thickness of 50-250 μm. The polymeric tubes with three-dimensional cross-linked network structures obtained in accordance with the sub-examples of Example 8 might be laser cut according to practical application requirements to form biodegradable vascular stents as shown in FIGS. 3( a ) to 3 ( g ). [0145] Stent Strength and Stability [0146] The stent shown in FIG. 3( b ) having an outside diameter of 3 mm, a wall thickness of 150 μm and a length of 2 cm was submersed in a 37° C. water bath held between two plates. A tensile test machine was used to compress the stent at a rate of 10 mm/min. When the compressive deformation of the stent reaches 15%, the stress value was recorded. For each type of the stents, 10 samples were tested and the data were averaged and shown in Table 3. Another group of samples was stored in vacuum packaging bags at the room temperature for 3 months and their strength was tested in the same way. The results showed that, the stents with three-dimensional cross-linked network structures had similar radial strength to metallic stents and the radial strength was stable with time and did not show significant decrease. [0000] TABLE 3 Radial strength (N/mm 2 ) Cross-linked PLA stent On the start day 0.131 ± 0.013 3 Months later 0.128 ± 0.008 [0147] During use of a biodegradable stent according to the present invention, it needs to be compressed over a non-inflated balloon of a stent delivery system in advance. After the stent has been delivered to a lesion site of a vessel, the balloon is inflated and the stent is expanded to form a support to the lesion site. Subsequently, the balloon is deflated and withdrawn from the body together with the delivery system. The polymeric tubes prepared in accordance with Example 8 with a three-dimensional cross-linked network structure have high mechanical strength, which provide the stents with sufficient radial compression resistance. In addition, when exposed to the body temperature, the polymeric stents according to the present invention can sense temperature increase and the three-dimensional network structures can exhibit a shape memory effect. This allows the stents to gradually regain their original diameters and reduces mechanical relaxation behavior of their polymeric materials to a maximum extent, which leads to reduced occurrence of stent retraction. [0148] Description of the foregoing examples is presented merely for facilitating the understanding of the core principles of the present invention. It is noted that while many modifications and variations can be made by those of ordinary skill in the art without departing from the inventive concept disclosed herein, it is intended that the appended claims cover all such modifications and variations. REFERENCES [0149] (1) Kelch S, Steuer S. et al., Shape-Memory Polymer Networks from oligo[(ε-hydroxycaproate)-co-glycolate]dimethacrylates and Butyl Acrylate with Adjustable Hydrolytic Degradation Rate, Biomacromolecules 2007, 8, 1018-1027. [0150] (2) Lendlein et al. Shape-Memory Polymer networks from oligo(ε-caprolactone) dimethacrylate J. Polym. Sci. Part A. 2005, 43, 1369. [0151] (3) Langer R. et al. U.S. Pat. No. 6,388,043 B1 shape-memory polymers, 2002. [0152] (4) Wang Y. D. et al. US2003/0118692 A1, Biodegradable polymers. [0153] (5) Bettinger C. J. et al. WO2007/082305 A2 Biodegradable elastomers. [0154] (6) Susawa T et al, Biodegradable intracoronary stents in adult dogs, J. Am. Coll. Cardiol. 1993, 21(supp 1), 483A. [0155] (7) Stack R. S. et al. Interventional cardiac catheterization at Duke Medical Center. Am. J. Cardiol. 1988, 62, 3F-24F. [0156] (8) Zidar J. P. et al, Short-term and long-term vascular tissue response to the Duke biodegradable stent. J. Am. Coll. Cardiol. 1993, 21, 439A. [0157] (9) Tamai et al. Initial and 6-month results of biodegradable P-1-lactic acid coronary stents in humans. Circulation, 2000, 102, 399-404. [0158] (10) Tsuji T, Tamai H, Igaki K, et al. One year follow-up biodegradable self-expanding stent implantation in humans. J Am Coll Cardiol 2001; 37(Abstr): A47. [0159] (11) Eberhart R. C. et al. Expandable biodegradable endovascular stent. I. Fabrication and properties. Annals of biomedical engineering, 2003, 31, 667-677. [0160] (12) Eberhart R. C. et al. Mechanical properties and in vitro degradation of bioresorbable fibers and expandable fiber-based stents, 2005, J. Biomed. Mater. Res. Part B: Appl. Biomater. 2005, 74B: 792-799. [0161] (13) Hietala E. M. et al, Biodegradation of the copolymeric polylactide stent, J. Vascular Research, 2001, 38, 361-369. [0162] (14) Välimaa T et al, Viscoelastic memory and self-expansion of self-reinforced bioabsorbable stents, Biomaterials, 2002, 23, 3575-3582. [0163] (15) Ye Y. W. et al, Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall, Annals of Biomedical Engineering, 1998, 3, 398-408. [0164] (16) Blindt R. et al, Long-term assessment of a novel biodegradable paclitaxel-eluting coronary polylactide stent, European Heart Journal, 2004, 25, 1330-1340. [0165] (17) Venkatraman S. S. et al, Biodegradable stent with elastic memory, Biomaterials, 2006, 27(8): 1573-8. [0166] (18) Gao R et al, A novel polymeric local heparin delivery stent: initial experimental study. J. Am. Coll. Cardiol. 1996, 27, 85A. [0167] (19) John A. Ormiston et al. First-in-Human Implantation of a Fully Bioabsorbable Drug-Eluting Stent: The BVS Poly-L-Lactic Acid Everolimus-Eluting Coronary Stent, Catheterization and Cardiovascular Interventions 69:128-131(2007).
The present invention relates to the field of medical instruments. Specifically, a biodegradable cross-linked polymer and a manufacturing method therefor are provided. The cross-linked polymer is obtained by bonding crosslinkable reactive groups to terminal groups of a biodegradable prepolymer having two or more arms and further subjecting the prepolymer to thermal polymerization and/or light irradiation. The cross-linked polymer has an elastic modulus of 10-4,500 MPa, and a degradation rate of 3-36 months. A biodegradable vascular stent and a preparation method therefor are also provided. The vascular stent is formed by laser cutting of polymeric tubing having a three-dimensional cross-linked network structure. The vascular stent has ample mechanical strength, a high elastic modulus at body temperature, and a regulatable degradation rate.
2
BACKGROUND OF THE INVENTION The invention relates to zigzag sewing machines in general and more particularly relates to a pattern cam driving mechanism of the zigzag sewing machine, in which a first group of pattern cams is rotated in association with the rotation of a drive shaft of the sewing machine with a reduced speed and a second group of pattern cams is rotated in association with the rotation of the first group of pattern cams with a further reduced speed with a transmission mechanism having a predetermined speed reduction ratio and provided between the first and second groups of pattern cams. Generally a sewing machine has a standardized size and accordingly the space within the machine housing is limited. Especially in a zigzag sewing machine of the type having a number of pattern cams incorporated or separately provided as being exchangeable, in any case, to cooperate with a cam follower which is swingable in accordance with the contours of the pattern cams, the diameter of the pattern cams has been accordingly limited resulting in the limitation in the number of stitches produced in one rotation cycle of the pattern cams and therefore the variation of stitched patterns has been limited. SUMMARY OF THE INVENTION Accordingly it is an object of the invention to provide a zigzag sewing machine which is able to produce a number of varied stitch patterns. It is another object of the invention to provide a predetermined number of pattern cams in a limited space of the machine housing, the pattern cams including a first group of pattern cams rotated with a predetermined speed and a second group of pattern cams rotated with a speed different from that of the first group of pattern cams. It is another object of the invention to provide a transmission mechanism between the first group of pattern cams and a second group of pattern cams, the transmission mechanism having a predetermined transmission ratio to vary the rotation speed of the second group of pattern cams from that of the first group of pattern cams. It is still another object of the invention to provide a pattern selecting device for selecting any of the first and second groups of pattern cams by moving a cam follower along the pattern cams. In short, the invention substantially comprises in combination a first group of pattern cams rotated in association with a drive shaft with a predetermined speed reduction; a second group of pattern cams rotated in association with the first group of pattern cams; transmission means arranged between the first and second groups of pattern cams to transmit the rotation of the first group of the pattern cams to the second group of pattern cams, the transmission means having a predetermined transmission ratio to vary the rotation speed of said second group of pattern cams from that of said first group of pattern cams: follower means including a cam follower which is swingable with respect to said first and second groups of pattern cams; means normally biasing the cam follower to engage a selected one of the first and second groups of pattern cams; and cam selecting means operated to disengage the cam follower by way of said biasing means and slidingly move the cam follower along said first and second pattern cams. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further objects and advantages of the invention will be fully understood from the following detailed description when read in conjunction with the accompanying drawings, in which: FIG. 1 is a plan view showing a first embodiment of the invention; FIG. 2 is a side elevational view of FIG. 1 partly eliminated; FIG. 3 is a perspective view of the invention; FIG. 4 is a standard pattern stitched by the invention; FIG. 5 is an elongated pattern of FIG. 4 stitched by the invention; FIG. 6 is a plan view of a second embodiment showing an essential part of the invention; FIG. 7 is a view taken on the line VII--VII of FIG. 6; FIG. 8 is an exploded view showing a part of FIG. 6; and FIG. 9 is a perspective view of an element according to the invention. DETAILED DESCRIPTION OF THE INVENTION In reference to FIGS. 1 to 3 showing a first embodiment of the invention, a machine housing 1 of a sewing machine has a pair of brackets 2, 3 fixedly arranged therein opposite to each other with a space provided therebetween. A pair of shafts 4, 5 are extended in parallel between the brackets 2, 3 and secured thereto. A control shaft 6 is extended between the brackets 2, 3 in parallel with the fixed shaft 5 on the left side thereof and is rotatable with respect to the brackets. The control shaft 6 has one end 6a projected out of the housing 1 on the front side of the sewing machine and a dial 19 secured to the end 6a thereof. Another control shaft 7 is rotatably arranged on the bracket 2 in parallel with the fixed shaft 4 on the right side thereof. The control shaft 7 has one end 7a projected out of the housing 1 on the front side of the sewing machine and a dial 12 secured to the projected end thereof. A drive shaft 8 is rotatably arranged in the housing 1 and extending longitudinally thereof. The drive shaft 8 has a worm 9 secured thereto. The worm 9 is in engagement with a worm gear 11 which is integral with a group of integrated pattern cams 10 mounted on the control shaft 6 and rotatable relative to the latter. As shown in FIG. 1, the control shaft 7 has an angle dividing disk 13 secured to the inner end thereof and a gear 14 secured to the angle dividing disk 13. A gear 16 is rotatably mounted on the fixed shaft 4 and an intermediate gear 15 is provided between the gear 14 and gear 16. The intermediate gear 15 is in engagement with the gears 14, 16 such that the rotation of the gear 14 is transmitted to the gear 16. The gear 16 is integral with a cylinder cam 17 for pattern selection and with a cam 18 for releasing cam followers from the pattern cams as will be described in detail herein. A cam 20 for varying the zigzag amplitude and a cam 21 for pattern selection are made integral with each other and secured to the control shaft 6. A U-shaped frame 23 is swingably mounted on the fixed shaft 5 and is normally spring-biased in the counterclockwise direction in FIGS. 2 and 3. As shown, the U-shaped frame 23 is formed with a groove 27 extended lengthwise thereof. A cam follower 22 is at the intermediate portion thereof turnably mounted on the fixed shaft 5. The cam follower has one end secured to the U-shaped frame 23 by means of a fastening screw 23a and the other end adapted to engage the cam 18 on the fixed shaft 4. A cam follower 22a has one end secured to the U-shaped frame 23 by means of a fastening screw 23b and the other end adapted to engage the cam 20 on the control shaft 6. As particularly shown in FIGS. 3 and 9, a slide member 24 is slidably and swingably mounted on the shaft 5 and a pair of cam followers 25, 25 are secured to one and the other ends of the slide member 24 respectively with a predetermined space being provided therebetween. Each of the cam followers 25 has an projection 26 normally engaging the guide groove 27 of the U-shaped frame 23. Further the slide member 24 is formed with a pair of projections 31 on both sides thereof. Each of the projections has a bent end 29 extended in parallel with the shaft 5. One of the projections 31 is adapted to engage the cylinder cam 17 on the shaft 4 and the other is adapted to engage the pattern selecting cam 21. The slide member 24 is normally spring-biased in the leftward direction in FIG. 3. Another group of integrated pattern cams 28 is rotatably mounted on the control shaft 6 adjacent to a gear 32 which is integral with the worm gear 11. The integrated pattern cams 28 have a gear 37 secured to the side thereof opposite to the gear 32. A pair of spaced gears 35, 36, which are made integral with each other, are rotatably mounted on a shaft 34 supported on an arm 33 which is secured to the bracket 3. The gear 35 is in engagement with the gear 32 and the gear 36 is in engagement with the gear 37 of the pattern cams 28 such that the rotation of the worm 11 is transmitted to the pattern cams 28 through the gears 32, 35, 36, 37. The rotation speed of pattern cams 28 will be varied from that of the pattern cams 10 in dependence upon the transmission ratio of the gears 32, 35, 36, 37. One of the cam followers 25 is adapted to cooperate with the group of pattern cams 10 and the other of the cam followers 25 is adapted to the group of pattern cams 28 to thereby swing the U-shaped frame 23 around the shaft 5 in accordance with the contour of a selected pattern cam. The swinging movement of the U-shaped frame 23 is transmitted to a needle (not shown) through an extension 45 of the frame 23 and a transmission rod 46. According to a second embodiment of the invention as shown in FIGS. 6 to 8, the group of the integrated pattern cams 10 having the worm gear 11 further has a sleeve 38 axially extended from the end of the worm gear 11. The sleeve has an end provided with a coaxial gear 39. Another group of integrated pattern cams 40 is rotatably mounted on the sleeve 38. The integrated cams 40 have an end formed with an internal gear 41. Three small gears 44 are rotatably mounted on a support disk 43 with a predetermined angular space being provided therebetween, and the support disk 43 is secured to the bracket 3 by means of fastening screws 42. The small gears 44 are arranged between the gear 39 of the sleeve 38 and the internal gear 41 of the pattern cams 40, and are in engagement with the gears 39 and 40 such that the rotation of the sleeve 38, which is rotated together with the worm 11, is transmitted to the pattern cams 40 through the series of gears 39, 44, 41. The rotation speed of the pattern cams 40 will be varied from that of the pattern cams 10 in dependence upon the transmission ratio of the series of gears 39, 44, 41. With the structure of the invention as mentioned above, the operation is as follows: When the drive shaft 8 is rotated, the group of pattern cams 10 is rotated on the shaft 6 through the worm 9 and the worm gear 11, and simultaneously the group of pattern cams 28 is rotated through the series of gears 32, 35, 36, 37 with a reduced speed determined by the transmission ratio of the series of gears 32, 35, 36, 37. For example, if the rotation speed of the pattern cams 10 is reduced to 1/8 of the rotation speed of the drive shaft 8 and the rotation speed of the pattern cams 28 is reduced to 1/36 of the rotation speed of the drive shaft 8, a pattern such as a crescent pattern actually obtained may be of a smaller size with a length L 1 by way of example as shown in FIG. 4 in case the corresponding pattern cam is selected from the group of pattern cams 10. On the other hand, the same crescent pattern actually obtained may be elongated twice to the size with a length L 2 by way of example as shown in FIG. 5 in case the corresponding pattern cam is selected from the group of pattern cams 28. The speed reduction of pattern cams 10, 28 may be optionally varied. According to the second embodiment of the invention, when the worm gear 11 is rotated, the pattern cams 10 are rotated together with the worm gear 11, and the rotation of the worm gear 11 is transmitted to the pattern cams 40 through the series of gears 39, 44, 41. The rotation speed of the pattern cams 10 and 40 may be optionally reduced with respect to the rotation speed of the drive shaft 8 just as in the case of the first embodiment. If the control shaft 7 is rotated by rotating the dial 12, the rotation is transmitted to the cylinder cam 17 by way of the gear 14 secured to the control shaft 7, the intermediate gear 15 and the gear 16 secured to the cylinder cam 17. When the cylinder cam 17 is rotated, which is engaged by one of the projections 31 of the slide member 24, the slide member 24 is slidingly moved along the shaft 5, and therefore one of the cam followers 25 is moved along the pattern cams 10 while the other cam follower 25 is moved in the space between the group of pattern cams 10 and another group of pattern cams 28. Thus the one of the cam followers 25 may be engaged to a selected one of the pattern cams 10. If the dial 12 is further rotated, the cylinder cam 17 moves the other of the cam followers 25 along the pattern cams 28 while the one of the cam followers 25 is moved in the space between the group of pattern cams 10 and the group of pattern cams 28. Thus the other cam follower 25 may be engaged to a selected one of the pattern cams 28. During the pattern cam selecting operation by means of the dial 12, the cam 18 is rotated together with the gear 16. The cam 18 timingly swings the follower 22 around the shaft and accordingly the U-shaped frame 23 is caused to swing around the shaft to thereby timingly disengage the cam follower 25 from the pattern cams 10 or 28. The cam follower 25 may therefore be moved along the pattern cams 10 or 28 as the dial is rotated. If the control shaft 6 is rotated by rotating the dial 19, the cam 21 is rotated, which is engaged by the other projection 31 of the slide member 24. When the cam 21 is rotated, one of the cam followers 25 is moved between the first three of the pattern cams 10 in this embodiment. One of the three pattern cams is for straight stitching and the other two are for buttonhole stitching. The cam 20, which is rotated together with the cam 21, cooperates with the follower 22a to slightly swing the U-shaped frame 23 to vary the extent of engagement between the follower 25 and one of the buttonhole cams, so as to produce a series of line-tack stitches on one side of buttonhole. The U-shaped frame 23 is swingingly moved around the shaft 5 in accordance with the contours of the pattern cams 10 or 28 by way of one or the other of the cam followers 25, and the swinging movement is transmitted to the needle of the sewing machine through the extension 45 of the frame 23 and the transmission rod 46. The embodiments of the invention are so constructed and operated as mentioned above, and therefore the structure of sewing machine is compact and the elongated patterns as well as the standard patterns may be optionally produced with easy pattern selecting operation.
In a zigzag sewing machine a first group of pattern cams is rotated with a predetermined speed relative to a second pattern cam group by the arrangement of a transmission means between the first and second groups. A biasing means normally biases a cam follower to engage a selected pattern cam in said first and second groups. Cam selecting means operate to disengage the cam follower by way of the bias means and slidingly move the follower to a selected position along the cam groups.
3
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improvement in a bearing beam structure installed to the bottom part of a cylinder block in order to rotatably support a crankshaft of an automotive internal combustion engine. 2. Description of the Prior Art In usual automotive internal combustion engines, a crankshaft is rotatably supported through bearing metals by a plurality of bearing sections formed at the bottom part of a cylinder block and a plurality of bearing caps which are secured respectively to the cylinder block bearing sections. The bearing caps are installed in positions separate and independent from each other, and accordingly tend to vibrate in fore and aft directions (in the direction of the crankshaft axis) and to come down under the influence of vibration input from the crankshaft due to combustion impact force. This excites vibration of the skirt section of a cylinder block, thereby emitting considerable noise. In view of this, a bearing beam has been proposed in which a plurality of bearing caps are integrally connected with each other by means of a rigid elongated beam located at the bottom part of each bearing cap section. Such a bearing beam structure is effective for preventing each bearing cap from vibrating in the fore and aft direction, but not effective against, for example, the torsional deformation of the cylinder block around the crankshaft axis, thereby allowing noise generation due to such vibration of the cylinder block. SUMMARY OF THE INVENTION A bearing beam structure according to the present invention is secured to the bottom part of a cylinder block of an internal combustion engine. The bearing beam structure comprises a plurality of main bearing cap sections a of which associates with each bearing section formed at the bottom part of the cylinder block so as to rotatably support the journal of a crankshaft therebetween. At least a beam section is connected to the lower end portion of each bearing cap section to securely connect all the bearing cap sections with each other. Additionally, first and second side wall sections are respectively connected to the opposite side portions of each bearing cap section to securely connect all the bearing cap sections with each other. Therefore, the bearing beam structure is greatly improved in torsional and flexural strength. This improves the rigidity of the entire cylinder block and suppresses deformation of a cylinder block skirt section, thereby effectively reducing noise emission from the engine. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the bearing beam structure according to the present invention will be better appreciated from the following description taken in conjunction with the accompanying drawings in which the same reference numerals designate the corresponding parts and elements, in which: FIG. 1 is a front elevation of a cylinder block equipped with a conventional bearing beam structure; FIG. 2 is a vertical sectional view taken in the direction of the arrows substantially along the line II--II of FIG. 1; FIG. 3 is a perspective view of the conventional bearing beam structure of FIG. 1; FIG. 4 is a vertical sectional view of a cylinder block equipped with a preferred embodiment of a bearing beam structure in accordance with the present invention; FIGS. 5A to 5E are plan view, front elevation, bottom view, side view, and sectional view, respectively, of the bearing beam structure of FIG. 4; and FIGS. 6A to 6E are similar to FIGS. 5A to 5E, respectively, but showing another embodiment of the bearing beam structure in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 to 3, a conventional bearing beam structure of an automotive internal combustion engine will be described along with its major shortcomings. The bearing beam structure 1 is securely installed on the bottom part of a cylinder block 2 of the engine and includes a beam section 3 which integrally connects a plurality of bearing cap sections 4 with each other in the fore and aft direction of the engine, thus forming a bearing beam structure of the one-piece type. The bearing cap sections 4 are respectively secured to the bearing sections 5 of the cylinder block 2, so that a crankshaft (not shown) is rotatably supported by the cylinder block bearing sections and the bearing beam structure bearing cap sections. With such a bearing beam structure, the bearing cap sections are prevented from moving by virtue of the beam section 3 and therefore each bearing cap section 4 is suppressed in its coming down vibration (vibration in fore and aft direction). Additionally, the rigidity of the cylinder block 2 is improved against flexure indicated in phantom in FIG. 1, thus suppressing the vibration of the skirt section 6 of the cylinder block 2. This reduces noise emission from the cylinder block skirt section 6. However, the above-mentioned bearing beam structure 1 has encountered the following shortcomings: The bearing beam structure 1 is not effective for suppressing torsional deformation of the cylinder block 2 around the axis of the crankshaft since the bearing cap sections 4 are connected only at their bottom end portion with each other. Besides, the bearing beam structure 1 is not so effective for suppressing flexure applied to each bearing cap section around the axis of each cylinder bore as indicated by arrows in FIG. 3. Thus, the cylinder block 2 and the bearing beam structure 1 emit vibration noise due to such deformations, not giving a sufficient engine noise reduction. In view of the above description of the conventional bearing beam structure, reference is now made to FIGS. 4 to 5E, wherein a preferred embodiment of a bearing beam structure 10 of the present invention is shown in combination with a cylinder block 12 of an automotive internal combustion engine. The cylinder block 12 is formed with a plurality of cylinder barrels 14 each of which defines therein a cylinder bore (no numeral). The cylinder block includes a skirt section 16 which bulges outwardly and extends downwardly to define an upper part of a crankcase (no numeral). The skirt section 16 is integrally connected through a lower block deck 18 with the cylinder barrels 14. A plurality of main bearing bulkheads 20 are aligned parallel with each other and located inside the skirt section 16. Each bearing bulkhead 20 is located below and connected to a portion between the adjacent two cylinder barrels 14. The bearing bulkhead 20 is integrally connected at its top part with the lower block deck 18 and at its sides with the inner wall of the skirt section 16. Each bearing bulkhead 20 is provided at its bottom central portion with a bearing section 22 defining the top of a bore 24 in which the journal of a crankshaft (only its axis X is shown) is rotatably disposed. The bearing beam structure 10 is securely connected to the bottom part of the cylinder block 12 and includes a plurality of main bearing cap sections 26. Each bearing cap section 26 defines the bottom of the bore 24 and is secured onto a bearing bulkhead 20 by means of cap bolts 28 so as to associate with the bearing section 22 of the bearing bulkhead 20, thereby rotatably supporting the journal of the crankshaft in the bore 24. The cap bolts 28 respectively pass through bolt holes 29 of the bearing cap sections 26. In this case, the bearing cap section 28 is generally in the shape of a rectangle, as viewed in the direction of the crankshaft axis X, whose top part has a width generally corresponding to that of the widened bottom part of the skirt section 16. All the bearing cap sections 26 are integrally connected with each other by two side wall sections 30A, 30B which are generally vertical and form opposite side walls of the bearing beam structure 10. The two side wall sections 30A, 30B extend parallel along the crankshaft axis X and are located at or formed respectively along the opposite side portions of each bearing cap section 26. The two side wall sections 30A, 30B are symmetrical with each other with respect to a vertical plane (not shown) containing the crankshaft axis X. These side wall sections 30A, 30B are formed respectively with flanges 32 which are secured to the bottom end portion of the cylinder block skirt section 16 by means of bolts 34, thus forming part of a crankcase. Furthermore, all the bearing cap sections 26 are integrally connected with each other by an elongate central beam section 36 and side beam sections 38A, 38B, all the beam sections extending parallel along the crankshaft axis X. The central beam section 36 is located at or formed along the center of the bottom portion of each bearing cap section 26, while the side beam sections 38A, 38B are respectively located at or formed along the opposite sides of the bottom portion of each bearing cap section 26. These side beam sections 38A, 38B are respectively integral with the side wall sections 30A, 30B at the bottom thereof. The bottom surface of bearing beam structure 10 is formed with flanges 40 to which an oil pan 42 is installed by means of bolts 44 threaded into bolt holes 46 of the flange 40. In this instance, the flanges 40 are integral respectively with the side beam sections 38A, 38B. The bearing beam structure 10 of this embodiment is produced by being integrally cast using a light alloy, such as an aluminum alloy, so that the bearing beam structure is of the one-piece type. With the thus arranged bearing beam structure 10, the coming down vibration of each bearing cap section is of course suppressed in the fore and aft direction. Additionally, each bearing cap section 26 is greatly improved in strength against bending force applied around the axis of each cylinder bore, thereby effectively suppressing torsional and flexural vibrations of each bearing section 22. As a result, noise emission from the cylinder block skirt section 16 is reduced. Furthermore, the entire cylinder block 12 is improved in strength against torsion around the crankshaft axis X, and the cylinder block skirt section 16 is prevented from opening and closing movement or deformation. The combined effect of these effectively suppresses noise generation and emission from the engine. Moreover, as a result of the fact that the bearing beam structure 10 forms part of the crankcase, the oil pan 42 may be smaller in size, thereby noticeably reducing noise generation in the oil pan 42. FIGS. 6A to 6E illustrate another embodiment of the bearing beam structure according to the present invention, in which the bearing beam structure 10 is formed at its rear end with a support arm section 48 which is to be connected to a transmission housing at the peripheral portion of the open end section, though not shown. The support arm section 48 is smoothly integral with the beam sections 36, 38A, 38B and the side wall sections 30A, 30B, and is formed at its tip with a through-hole 50 for a bolt (not shown) by which the support arm section 48 is bolted to the transmission housing. With this embodiment, the connection-rigidity between the cylinder block 12 and the transmission is improved thereby reducing low frequency noise generated within a vehicle passenger compartment which noise is due to lack of connection-rigidity. Additionally, opening and closing movement vibration of the open end section of the transmission housing is also suppressed, thus preventing noise generation from the transmission housing. As will be appreciated from the above, the bearing beam structure according to the present invention effectively suppresses torsional vibration etc. of each bearing cap section, and greatly improves the rigidity of the entire cylinder block, thus achieving greater noise reduction as compared with a conventional bearing beam structure.
A bearing beam structure is secured to a cylinder block of an internal combustion engine and includes a plurality of main bearing cap sections each of which associates with each bearing section of the cylinder block so as to rotatably support a crankshaft. At least a beam section is rigidly connected to the lower end portion of each bearing cap section to securely connect all the bearing cap sections with each other. Additionally, first and second side wall sections are rigidly connected to the opposite side portions of each bearing cap section to securely connect all the bearing cap sections with each other. Accordingly, the bearing beam structure is improved in rigidity to suppress various vibrations of the cylinder block, thereby effectively achieving total engine noise reduction.
5
BACKGROUND OF THE INVENTION The invention relates to the field of intravascular medical devices, and more particularly to a balloon for a catheter. In percutaneous transluminal coronary angioplasty (PTCA) procedures, a guiding catheter is advanced until the distal tip of the guiding catheter is seated in the ostium of a desired coronary artery. A guidewire, positioned within an inner lumen of an dilatation catheter, is first advanced out of the distal end of the guiding catheter into the patient's coronary artery until the distal end of the guidewire crosses a lesion to be dilated. Then the dilatation catheter having an inflatable balloon on the distal portion thereof is advanced into the patient's coronary anatomy, over the previously introduced guidewire, until the balloon of the dilatation catheter is properly positioned across the lesion. Once properly positioned, the dilatation balloon is inflated with liquid one or more times to a predetermined size at relatively high pressures (e.g. greater than 8 atmospheres) so that the stenosis is compressed against the arterial wall and the wall expanded to open up the passageway. Generally, the inflated diameter of the balloon is approximately the same diameter as the native diameter of the body lumen being dilated so as to complete the dilatation but not overexpand the artery wall. Substantial, uncontrolled expansion of the balloon against the vessel wall can cause trauma to the vessel wall. After the balloon is finally deflated, blood flow resumes through the dilated artery and the dilatation catheter can be removed therefrom. In such angioplasty procedures, there may be restenosis of the artery, i.e. reformation of the arterial blockage, which necessitates either another angioplasty procedure, or some other method of repairing or strengthening the dilated area. To reduce the restenosis rate and to strengthen the dilated area, physicians frequently implant an intravascular prosthesis, generally called a stent, inside the artery at the site of the lesion. Stents may also be used to repair vessels having an intimal flap or dissection or to generally strengthen a weakened section of a vessel. Stents are usually delivered to a desired location within a coronary artery in a contracted condition on a balloon of a catheter which is similar in many respects to a balloon angioplasty catheter, and expanded to a larger diameter by expansion of the balloon. The balloon is deflated to remove the catheter and the stent left in place within the artery at the site of the dilated lesion. Catheter balloons are typically manufactured independently of the catheter shaft and then secured to the catheter shaft with an adhesive or other bonding method. In standard balloon manufacture, a polymer tube is blown biaxially under the action of axial tension, internal pressure, and heat within a mold. The polymer tube may either be simultaneously stretched in the radial and axial directions, or sequentially, by first stretching axially and then radially. The starting dimensions of the polymer tube and the finished dimensions of the blow-molded balloon within the mold are a measure of the degree to which the polymeric material has been stretched and oriented during balloon blowing, and affect important characteristics of the finished balloon such as rupture pressure and compliance. The blow-up-ratio (BUR), namely, the ratio of the outer diameter of the blown balloon (i.e., the mold inner diameter) to the inner diameter of the polymer tube, is a measure of those dimensions. Beyond a critical BUR for a given polymer, the balloon blowing process becomes unstable and the polymer tubing often ruptures or tears before a balloon is fully formed. In the standard blow molding process, an initiated bubble rapidly grows in diameter until it is constrained by the mold wall. The hoop stress in the wall of the tubing, as it grows into a balloon, may be approximated by the expression: σ h =( P·R )/δ where P is the inflation pressure, R is the mean radius of the polymeric tube at any time during the inflation and δ, delta, is the wall thickness of the tubing. For a balloon to be initiated from the tubing, the inflation pressure should be such that the wall hoop stress exceeds the material resistance (typically the yield stress) to stretching at the blowing temperature. Once a balloon is initiated from the tubing, it grows rapidly in size until it touches the mold wall. As the balloon grows, the radius increases and the balloon wall thickness decreases. This results in a rapid increase in the wall hoop stress during constant pressure blowing. If the wall hoop stress of the growing balloon exceeds the ultimate hoop strength of the material, rupture will occur. As a result, there is a limit to the BUR (i.e., a maximum attainable BUR) of a polymeric material forming the balloon layer(s). In the design of catheter balloons, balloon characteristics such as strength, flexibility and compliance must be tailored to provide optimal performance for a particular application. Angioplasty and stent delivery balloons preferably have high strength for inflation at relatively high pressure, and high flexibility and softness for improved ability to track the tortuous anatomy and cross lesions. The balloon compliance, which depends on factors such as the nature of the balloon material, the balloon wall thickness, and processing conditions, is chosen so that the balloon will have a desired amount of expansion during inflation. Compliant balloons, for example balloons made from materials such as polyethylene, exhibit substantial stretching upon the application of tensile force. Noncompliant balloons, for example balloons made from materials such as PET, exhibit relatively little stretching during inflation, and therefore provide controlled radial growth in response to an increase in inflation pressure within the working pressure range. However, noncompliant balloons generally have relatively low flexibility and softness, so that it has been difficult to provide a low compliant balloon with high flexibility and softness for enhanced catheter trackability. A balance is typically struck between the competing considerations of softness/flexibility and noncompliance, which, as a result, has limited the degree to which the compliance of catheter balloons can be further lowered. Therefore, what has been needed is a catheter balloon with very low compliance, yet with excellent ability to track within the patient's vasculature and cross lesions therein. The present invention satisfies these and other needs. SUMMARY OF THE INVENTION The invention is directed to a balloon catheter having a multilayered balloon which has a first layer and at least a second layer, and which has noncompliant limited radial expansion beyond the nominal diameter of the balloon. By selecting the polymeric materials forming the balloon layers, and arranging and radially expanding the multiple layers of the balloon in accordance with the invention, a balloon is provided having an improved low compliance, preferably in combination with high flexibility and softness. A multilayered balloon of the invention is preferably formed in whole or in part of coextruded polymeric tubular layers, and provides for ease of manufacture of the balloon and balloon catheter formed therefrom. The multilayered balloon is typically formed by conventional blow-molding in which a multilayered polymeric tube is radially expanded within a balloon mold. The resulting multilayered balloon has an inflated shape which corresponds to the inner surface of the mold and which has a diameter about equal to the inner diameter of the balloon mold, commonly referred to as the balloon's nominal working diameter. The nominal pressure is the inflation pressure required to fill the balloon to the nominal working diameter. In accordance with the invention, the balloon expands a very small amount (i.e., noncompliantly) at pressures above the nominal pressure. As a result, the balloon minimizes injury to a patient's blood vessel, which can otherwise occur if the balloon continues to expand a substantial uncontrolled amount at increasing inflation pressures above nominal. As discussed above, the blow-up-ratio (BUR) of the balloon formed from a polymer tube should be understood to refer to the ratio of the outer diameter of the blown balloon expanded within the mold (i.e., the mold inner diameter) to the inner diameter of the polymer tube prior to being expanded in the mold. Each individual layer of the multilayered balloon similarly has its own BUR based on the ratio of the inner diameter of the mold and the inner diameter (prior to expansion in the mold) of the layer of the polymeric tube. For a given balloon wall thickness, the rupture strength generally increases and the radial compliance decreases as the balloon BUR increases. For standard pressure driven blow molding of catheter balloons, typical BURs range from about 4.5 to about 8.0 depending on the material and the product application. A method of making a balloon of the invention increases the amount of balloon material that is highly oriented in the radial direction, to provide a balloon with limited radial expansion at increasing inflation pressures (i.e., to provide a noncompliant balloon). Specifically, a multilayered balloon of the invention has polymeric materials that can be expanded to higher BURs as the inner layer(s) of the balloon, while lower BUR materials are the outer layer(s) of the balloon. In a presently preferred embodiment, the balloon has a first layer of a first polymeric material and a second layer of a second polymeric material which has a lower Shore durometer hardness than the first polymeric material and which can be expanded during balloon blowing to a higher BUR (without rupturing or tearing) than the higher Shore durometer hardness material of the first layer, and the second layer is an inner layer relative to the first layer. For example, one embodiment, the multilayered balloon inner layer is formed of a polyether block amide (PEBA) material (e.g., commercially available as PEBAX®) having a Shore durometer hardness of about 60-70D while the outer layer is formed of a PEBA material having a higher Shore durometer hardness of about 70-72D. However, a variety of suitable materials can be used including materials which are of the same material classification/family, or different classes of materials. The multilayered balloon generally has two or more layers (i.e., layers formed of materials which differ in some respect such as different Shore durometer hardnesses), although it typically does not have more than five layers. Despite presence of the lower durometer material forming the second (inner) layer of the multilayered balloon, a first embodiment of the invention provides a balloon which has a very low compliance. For example, a balloon of the invention having a first (outer) layer of a first durometer, and one or more inner layer(s) of successively lower durometers (i.e., increasingly softer materials), has a lower compliance than a balloon having about the same wall thickness but formed of 100% of the highest durometer material (i.e., the material forming the outer-most layer of the balloon of the invention). Compared to a balloon formed of 100% of the highest durometer material, a balloon of the invention has effectively replaced a part of the balloon wall thickness with the layer(s) of lower durometer (softer) material(s), which would typically be expected to increase the compliance. While not wishing to be bound by theory, it is believed that the balloon provides the noncompliant behavior through the specific combination of highly oriented layers of the balloon, and particularly by maximizing the orientation of the inner layer(s) of the balloon. The inner layer orientation significantly affects compliance of the balloon. By selecting and arranging different materials that can be blown to different BURs in accordance with the invention, the balloon has layers with successively increasing BURs from the outer to the inner layer(s), such that the BUR of each layer is preferably maximized and the inner layer(s) have particularly high BURs. The layers of the balloon are therefore optimized for compliance purposes. Although additional layers may be added to the balloon, to, for example, increase the total wall thickness to a desired value, the arrangement of the basic layers in accordance with the invention cannot be varied without resulting in a higher compliance balloon. Additionally, the invention can alternatively provide for a balloon with a low compliance but with very thin walls. For example, one embodiment is directed to a multilayered balloon having a first (outer) layer of a first durometer material and one or more inner layer(s) of successively lower durometer materials which has a compliance not substantially greater than (e.g., not more than about 10% to about 20% greater than), and preferably about equal to a balloon which is formed of 100% of the highest durometer material but which has a larger wall thickness than the multilayered balloon of the invention. The embodiment of the balloon having a very thin total wall thickness provides an improved low profile and flexibility due to the thinner walls of the balloon, but, in accordance with the invention, nonetheless continues to provide a low compliance despite the thin wall. The rupture pressure and compliance of a balloon are affected by the strength (e.g., hoop strength) of a balloon. Because a softer material generally has a relatively lower hoop strength, the presence of the lower durometer material forming the inner layer(s) of the balloon is not generally expected to provide a relatively higher modulus balloon. However, a multilayered balloon of the invention preferably has a higher modulus than, and a rupture pressure which is not substantially less than, a balloon formed of 100% of the highest durometer material. The presence of the lower durometer material inner layer(s) does provide layers of increased softness, and therefore preferably provides a balloon that is softer and more flexible than a balloon formed of 100% of the highest durometer material. Prior multilayered balloons with layers of polymers having different strengths/softnesses typically arrange the layers so that the durometer hardnesses decreased from the inner to the outer layer, for various balloon design considerations. For example, lower durometer (softer) materials are typically preferred as outer layers for design considerations such as pinhole resistance, stent retention, and the like. In contrast, a balloon of the invention arranges layers so that the highest durometer material has on an inner surface thereof a layer of a lower durometer material, and configures the layers to provide for a maximized BUR which produces an improved combination of characteristics including a very low compliance. However, with the inner layer(s) of the balloon of the invention optimized for compliance purposes as discussed above, one embodiment of a balloon of the invention has an outer-most layer of a relatively soft material, to, for example, enhance stent retention. The compliance of the balloon should be understood to refer to the degree to which the polymeric wall of the balloon stretches/distends as the balloon expands beyond the nominal diameter of the balloon. The compliance curve expresses the balloon outer diameter as a function of increasing inflation pressure in millimeters/atmospheres (mm/atm), so that a steeper curve or section of the curve indicates a higher compliance than a flatter curve. The term “noncompliant”, should be understood to mean a balloon with compliance of not greater than about 0.03 mm/atm, preferably not greater than about 0.025 mm/atm. In contrast, compliant balloons typically have a compliance of greater than about 0.045 mm/atm. A noncompliant balloon of the invention generally has a compliance above nominal of about 0.01 to about 0.02 mm/atm, for a 3.0 mm diameter balloon. The compliance of the balloon is typically about 25% to about 50% less than the compliance of a balloon with a similar wall thickness but made from 100% of the first (e.g., highest durometer) material. In a presently preferred embodiment, the polymeric material of the first layer and the polymeric material of the second layer of the multilayered balloon are elastomers, which typically have a lower flexural modulus than nonelastomers. Elastomeric polymers suitable for forming the first and/or second layer of the multilayered balloon typically have a flexural modulus of about 40 kpsi to about 110 kpsi. Thus, unlike nonelastomeric materials such as PET which have been used in the past to provide relatively low compliance catheter balloons, the multilayered noncompliant balloon of the invention is preferably formed of one or more elastomers which provide for improved balloon flexibility. One aspect of the invention is directed to a method of making a noncompliant multilayered balloon for catheter. The method generally comprises selecting a first and a second polymeric material, the second polymeric material having been determined to have a higher maximum attainable BUR than the first polymeric material, and forming a multilayered tube having a first layer of the first polymeric material, and a second layer of the second polymeric material wherein the second layer is an inner layer relative to the first layer. The maximum attainable BUR of a polymeric material is typically determined experimentally, although characteristics such as the ultimate tensile strength and elongation to break of the material maybe indicative at least for some materials (e.g., a material having a relatively higher ultimate tensile strength and elongation to break is expected, in general, to have a higher maximum BUR). The inner diameter of each layer of the multilayered tube is selected so that the ratio of the inner diameter of the balloon mold and the inner diameter of the layer of the multilayered tube (prior to being radially expanded in the balloon mold) is substantially at a maximum blow-up-ratio for the polymeric material forming the layer. Thus, the method includes forming the blow-molded multilayered balloon by radially expanding the multilayered tube in a mold, so that radially expanding the tube to the mold inner diameter radially expands each layer substantially to the maximum blow-up-ratio of the polymeric material forming the layer, such that the multilayered balloon has a lower compliance above the nominal working diameter than a balloon consisting of the first elastomeric polymeric material. Various designs for balloon catheters well known in the art may be used in the catheter system of the invention. For example, conventional over-the-wire balloon catheters for angioplasty or stent delivery usually include a guidewire receiving lumen extending the length of the catheter shaft from a guidewire proximal port in the proximal end of the shaft to a guidewire distal port in the catheter distal end. Rapid exchange balloon catheters for similar procedures generally include a relatively short guidewire lumen extending from a guidewire port located distal to the proximal end of the shaft to the catheter distal end. The multilayered balloon of the invention provides a very low compliance for controlled balloon expansion, without compromising relatively high flexibility and softness for excellent ability to track the patient's vasculature and cross lesions. As a result, the balloon catheter of the invention has improved performance due to the flexibility, softness, and controlled expansion of the balloon. The balloon provides the surprising result of a very low compliance from the addition of the lower durometer (softer) second material. Consequently, a multilayered balloon of the invention will provide a much lower compliance than a balloon with the same wall thickness but made from just the higher durometer (stiffer) material, or will provide a much thinner walled balloon but without the expected increase in compliance. These and other advantages of the invention will become more apparent from the following detailed description of the invention and the accompanying exemplary drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partially in section, of an over-the-wire type stent delivery balloon catheter embodying features of the invention. FIGS. 2 and 3 are transverse cross sectional views of the catheter of FIG. 1 , taken along lines 2 - 2 and 3 - 3 , respectively. FIG. 4 illustrates the balloon catheter of FIG. 1 with the balloon inflated. FIG. 5 is a longitudinal cross sectional view of multilayered balloon tubing in a balloon mold prior to being radially expanded therein, in a method embodying features of the invention. FIG. 6 is graphical compliance data, with balloon diameter measured in millimeters as the ordinate and inflation pressure measured in atmospheres as the abscissa, comparing a multilayered balloon of the invention with a single layered balloon formed of 100% of the highest durometer material. FIG. 7 is graphical modulus data, with balloon modulus in kpsi as the ordinate and inflation pressure measured in atmospheres as the abscissa, comparing a multilayered balloon of the invention with a single layered balloon formed of 100% of the highest durometer material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a stent delivery balloon catheter 10 which embodies features of the invention, generally comprising an elongated catheter shaft 11 having a proximal shaft section 12 , a distal shaft section 13 , an inflation lumen 21 , and a guidewire lumen 22 configured to slidably receive a guidewire 23 therein, and having a balloon 14 mounted on the distal shaft section. An adapter 17 on a proximal end of the catheter shaft provides access to the guidewire lumen 22 , and has an arm 24 configured for connecting to a source of inflation fluid (not shown). FIG. 1 illustrates the balloon in a noninflated configuration for advancement within a patient's body lumen 18 . A radially expandable stent 16 is releasably mounted on the balloon 14 for delivery and deployment within the body lumen 18 . The balloon catheter 10 is advanced in the body lumen 18 with the balloon 14 in the noninflated configuration, and the balloon inflated by introducing inflation fluid into the balloon interior to expand the balloon 14 and stent 16 mounted thereon. FIG. 4 illustrates the balloon catheter 10 with the balloon in the inflated configuration to expand the stent against the wall of the body lumen 18 . The balloon 14 is then deflated to allow for repositioning or removal of the catheter from the body lumen 18 , leaving the stent 16 implanted in the body lumen 18 . In the illustrated embodiment, the shaft comprises an outer tubular member 19 defining the inflation lumen 21 , and an inner tubular member 20 defining the guidewire lumen 22 and positioned in the outer tubular member 19 such that the inflation lumen 21 is the annular space between the inner surface of the outer tubular member 19 and the outer surface of the inner tubular member 20 , as best shown in FIG. 2 illustrating a transverse cross section of the catheter of FIG. 1 , taken along line 2 - 2 . The balloon 14 has a proximal skirt section sealingly secured to the distal end of the outer tubular member 19 , and a distal skirt section sealingly secured to a distal end of the inner tubular member 20 , so that an interior 15 of the balloon is in fluid communication with the inflation lumen 21 of the shaft. FIG. 3 illustrates a transverse cross section of the catheter of FIG. 1 , taken along line 3 - 3 , although the space between the inner surface of the noninflated balloon and the outer surface of the portion of the shaft 11 therein is somewhat exaggerated in FIGS. 1 and 3 , for ease of illustration. A variety of alternative suitable catheter shaft configurations can be used as are conventionally known. Although not illustrated, the balloon 14 of the invention typically has a noninflated configuration with wings wrapped around the balloon to form a low profile configuration for introduction and advancement within a patient's body lumen. As a result, the balloon inflates to a nominal working diameter by unfolding and filling the molded volume of the balloon. Balloon 14 has a first layer 30 , and a second layer 31 which is an inner layer relative to the first layer 30 . In the illustrated embodiment, the second layer 31 is on an inner surface of the first layer 30 , with the first layer 30 defining an outer surface of the balloon 14 and the second layer 31 defining an inner surface of the balloon 14 . However, the balloon 14 of the invention can alternatively have one or more additional layers (not shown). Additional layer(s) increase the dimensions of the tube/balloon formed therefrom to a desired value, and/or can be used to provide an inner or outer surface of the balloon with a desired characteristic. Therefore, it should be understood that the balloon 14 of the invention discussed below has at least two layers, and optionally includes one or more additional layers, unless otherwise noted as having a specified set number of layers. The first (outer) layer 30 is formed of a first polymeric material, and the second (inner) layer 31 is formed of a second polymeric material that can be expanded to a higher BUR than the first polymeric material. The second (inner) layer 31 is at a BUR which is typically about 15% to about 40% greater than the BUR of the first (outer) layer 30 . Each layer 30 , 31 is preferably at its maximum BUR, so that the balloon has layers of highly oriented material and, consequently, a very low compliance. A variety of suitable materials can be used to form the first and second layers 30 , 31 , including polyamides, polyurethanes, and polyesters. In a presently preferred embodiment, the first and second polymeric materials are elastomers providing a relatively low flexural modulus for balloon flexibility, although nonelastomers can alternatively be used. Presently preferred materials are from the same polymeric family/class such as polyamides including nylons and polyether block amides (PEBAX). Forming the layers of compatible polymeric materials allows for heat fusion bonding the layers together. The layers can alternatively be formed of different polymer classes which are not sufficiently compatible to fusion bond together, in which case a tie layer is typically provided between the outer and inner layers 30 , 31 to bond the balloon layers together. For example, a PET inner layer and a PEBAX typically have a tie layer of an adhesive polymer such as Primacor (a functionalized polyolefin) therebetween. The balloon 14 is formed by a method in which the layers of material that can be expanded to higher BURs are the inner layers of the balloon tubing, and lower BUR materials are the outer layers, and the balloon is blow-molded such that each layer is optimized for radial orientation. The resulting balloon has an increased resistance to radial expansion at increasing inflation pressures. The balloon 14 is blow-molded from a multilayered tube which has the first layer 30 , and the second layer 31 as an inner layer relative to the first layer 30 . However, as discussed above, a balloon of the invention may have one or more additional layers, so that the tubing used to blow-mold the balloon would similarly be formed with the additional layer(s). The tube is typically formed by coextrusion, although a variety of suitable method may be used. For example, in one embodiment, a multilayered tube is formed by coextruding at least two layers, and one or more additional layers are added to the coextruded tube for example by heat shrinking, dip coating, adhesive or fusion bonding, or frictionally engaging the additional layer(s) to the coextruded tube. The multilayered tube is then radially expanded in a balloon mold to form the balloon 14 . FIG. 5 illustrates the multilayered tube 40 in a balloon mold 41 having an interior chamber 42 with a shape configured to form the balloon 14 , and an inner diameter about equal to the nominal working diameter of the expanded balloon 14 . The multilayered tube 40 is typically stretched axially and heated during blow molding in the balloon mold, as is conventionally known. For example, in one embodiment, the tube is longitudinally stretched by about 200% during blow molding, which produces a biaxially oriented balloon. The single wall thickness of the tube (prior to being radially expanded in the mold) is about 0.1 to about 0.4 mm, and the single wall thickness of the resulting balloon (radially expanded in the mold) is about 0.01 to about 0.04 mm, depending on the desired balloon characteristics and uses. The materials and dimensions of the multilayered tube 40 and balloon mold 41 are selected so that each layer of the resulting balloon has been radially expanded to substantially its maximum possible amount, expressed as the BUR of the balloon layers. In a presently preferred embodiment, the outer layer 30 has a higher Shore durometer hardness and therefore lower elongation than the one or more inner layers. The elongation of each layer is typically about 10% to about 50%, and more specifically about 20% more than the elongation of the outer layer immediately adjacent thereto. In a presently preferred embodiment, the first (outer) layer 30 is a PEBAX having a Shore durometer hardness of about 72D, and the second (inner) layer 31 is a PEBAX having a Shore durometer hardness of about 63D. The PEBAX 72D outer layer 30 typically has a BUR of between about 6 and 7, and the PEBAX 63D inner layer 31 a BUR of between about 7 and 8. In one embodiment, a mid layer (not shown) of intermediate BUR and/or durometer hardness is provided between the outer and inner layers 30 , 31 . For example, in one presently preferred embodiment, the balloon 14 has a first, outer layer 30 of PEBAX 72D, a second, inner layer 31 of PEBAX 63D, and a midlayer (not shown) therebetween of PEBAX 70D. In a presently preferred embodiment, the inner and mid layers have a smaller wall thickness than the highest durometer layer therearound, and typically together make up about 5% to about 15% of the total wall thickness of the multilayered balloon. The balloon 14 can similarly have one or more additional layers (not shown) which similarly continue the pattern of sequentially increasing BUR and/or durometer from the inner toward the outer layers of the balloon. However, in one embodiment, the balloon 14 has a relatively soft outer-most layer (not shown) having a Shore durometer hardness less than the immediately adjacent inner layer of the balloon, which facilitates embedding the stent 16 into the outer surface of the balloon for improved stent retention. Such a relatively soft outer-most layer typically has of a relatively low Shore durometer hardness of about 40D to about 55D. The multilayered balloon of the invention has a low compliance, and a relatively high rupture pressure, particularly when compared to a balloon of otherwise similar construction but formed solely of the highest durometer material used to make the multilayered balloon of the invention (e.g., a 72D PEBAX outer layer of multilayered balloon 14 ), or compared to a balloon formed of layers of different durometer materials but not layered in accordance with the invention. The compliance is typically determined for the pressure range extending from the nominal pressure (i.e., the pressure required to fill the molded volume of the balloon to the blow-molded nominal diameter) to the burst pressure or the rated burst pressure of the balloon. The rated burst pressure (RBP), calculated from the average rupture pressure, is the pressure at which 99.9% of the balloons can be pressurized to without rupturing, with 95% confidence. The multilayered balloon 14 has a nominal pressure of about 6 to about 12 atm, and more typically of about 7 to about 9 atm, and a RBP of about 14 to about 22 atms, more typically about 18 to about 20 atms. The rupture pressure is typically about equal to, greater than, or not substantially less than (i.e., not more than about 5% to about 15% less than) a rupture pressure of a balloon of otherwise similar construction but formed solely of the highest durometer material. In one embodiment, a multilayered balloon of the invention having at least a 72D PEBAX outer layer and a 63D PEBAX inner layer reaches the nominal diameter of the balloon at about 8 to about 9 atm, and thereafter stretches in a noncompliant manner with a compliance of about 0.01 to about 0.02 mm/atm within the working pressure range (e.g., 8-20 atm) of the multilayered balloon to a diameter which is not more than about 8% greater than the nominal diameter. Due to the presence of the softer durometer inner layer(s), the flexural modulus of a multilayered balloon of the invention is expected generally to be about 90% to about 95% of the flexural modulus of a balloon consisting of the first (e.g., higher durometer) elastomeric polymeric material of the layer 30 . EXAMPLE Multilayered balloon tubing, formed by coextrusion, had overall dimensions of 0.0155 inch inner diameter (ID) and 0.0365 inch outer diameter (OD). The tubing had an inner layer of 63D PEBAX with a wall thickness 0.001 inches, a midlayer of 70D PEBAX with a wall thickness of 0.001 inches, and an outer layer of 72D PEBAX with a wall thickness of 0.0085 inches. Wall thickness values are a single wall thickness, unless otherwise identified as a double wall thickness (DWT). The tubing was blow-molded by heating and pressurizing the tubing in a 0.1215 inch ID balloon mold in a single blow cycle, resulting in a multilayered balloon having an average wall thickness (DWT) of 0.00163 inches and the following BURs for the balloon layers: 63D Inner Layer ID of 0.0155 inch gives a BUR of 7.83 (0.1215/0.0155); 70D midlayer ID of 0.0175 inch gives a BUR of 6.94 (0.1215/0.0175); and 72 D outer layer ID of 0.0195 inch gives a BUR of 6.23 (0.1215/0.0195). The calculated BUR value of balloons may vary slightly depending on whether the ID of the mold or the OD of the balloon at blow is used for the calculation. The resulting multilayered balloon had overall dimensions of about 0.1214 inch ID and 0.1230 inch OD. The compliance and modulus of the multilayered balloon were compared to a comparison balloon similarly formed and with approximately the same wall thickness but from a single layer (100%) of the 72D PEBAX. The comparison balloon was blow-molded in a 0.1250 inch ID balloon mold, using balloon tubing extruded to a 0.0190 inch ID and a 0.0365 inch OD, to form a balloon having the desired wall thickness. The resulting balloon had an average wall thickness of 0.00165 inches and a BUR of 6.58 (0.1250/0.0190). The multilayered balloon of the invention and the comparison monolithic balloon each had a nominal pressure of about 8 atm, and a burst pressure of greater than 20 atm, and more specifically, an average rupture pressure of about 25 atm. The compliance curves of the multilayered balloon and the comparison monolithic balloon are shown in FIG. 6 , and are generated by inflating a balloon subassembly and measuring the change in the balloon outer diameter in response to increasing inflation pressures. As illustrated in FIG. 6 , the compliance from nominal (8 atm) to 20 atm is about 0.018 mm/atm for the multilayered balloon of the invention, compared to about 0.028 mm/atm for the monolithic comparison balloon. Thus, despite the presence of the lower durometer material mid and inner layers, such that the 72D PEBAX made up a smaller percentage of the wall thickness of the balloon than in the monolithic balloon made solely of 72D PEBAX, the multilayered balloon of the invention had a lower compliance. Specifically, the outer layer of PEBAX 72 D made up about 87% of the wall thickness of the multilayered balloon, compared to 100% of the monolithic balloon. Similarly, FIG. 7 illustrates the incremental modulus comparison (modulus value from P n to P n+1 ) of a trilayered Pebax 63D/70D/72D balloon of the invention and a monolithic Pebax 72D comparison balloon. The modulus of the multilayered balloon of the invention, illustrated graphically in FIG. 7 , is higher than the modulus of the monolithic comparison balloon. The modulus values are derived from the compliance curve data, and are specifically determined from the equation E =(( P n+1 D n+1 )/ DWT n+1 −( P n D n )/ DWT n )÷( D n+1 −D n )/ D n where E is modulus, P is inflation pressure, D is diameter, and DWT is double wall thickness. The BUR of the 72D PEBAX outer layer of the trilayer balloon of the invention is less than the BUR of the monolithic 72D PEBAX balloon. However, the multilayered balloon of the invention facilitates expanding the lower durometer inner layers to relatively high BURs, and provides a balloon with an overall BUR that is relatively high. The inner and mid layers are at relatively high BURs of about 7 to about 8, and preferably are at higher BURs than are possible if attempting to use the same blow-molding procedure to form a similar balloon but from 100% of the material of either the inner or the mid layer. For example, PEBAX 63D extruded to form tubing having an ID of 0.0195 inches and an OD of 0.0355 inches can not be blown into a 0.118 inch ID balloon mold (i.e., a BUR of 6) in a single blow cycle without rupturing during the blow-molding process. The absolute average wall thickness of the multilayered balloon in the above Example was about equal to the wall thickness of the monolithic balloon, allowing for a direct comparison of the compliance and modulus of the balloons. However, it should be understood that the wall thickness of the multilayered balloon of the invention could alternatively have been made less, so that the compliance and modulus comparisons would have been based on normalized wall thicknesses. The dimensions of catheter 10 are determined largely by the size of the balloon and guidewire to be employed, the catheter type, and the size of the artery or other body lumen through which the catheter must pass or the size of the stent being delivered. Typically, the outer tubular member 19 has an outer diameter of about 0.025 to about 0.04 inch (0.064 to 0.10 cm), usually about 0.037 inch (0.094 cm), and the wall thickness of the outer tubular member 19 can vary from about 0.002 to about 0.008 inch (0.0051 to 0.02 cm), typically about 0.003 to 0.005 inch (0.0076 to 0.013 cm). The inner tubular member 20 typically has an inner diameter of about 0.01 to about 0.018 inch (0.025 to 0.046 cm), usually about 0.016 inch (0.04 cm), and a wall thickness of about 0.004 to about 0.008 inch (0.01 to 0.02 cm). The overall length of the catheter 10 may range from about 100 to about 150 cm, and is typically about 143 cm. Preferably, balloon 14 has a length about 0.8 cm to about 6 cm, and an inflated working diameter of about 2 to about 5 mm. The various components may be joined using conventional bonding methods such as by fusion bonding or use of adhesives. Although the shaft is illustrated as having an inner and outer tubular member, a variety of suitable shaft configurations may be used including a dual lumen extruded shaft having a side-by-side lumens extruded therein. Similarly, although the embodiment illustrated in FIG. 1 is an over-the-wire type stent delivery balloon catheter, the catheter of this invention may comprise a variety of intravascular catheters, such as a rapid exchange type balloon catheter. Rapid exchange catheters generally comprise a shaft having a relatively short guidewire lumen extending from a guidewire distal port at the catheter distal end to a guidewire proximal port spaced a relatively short distance from the distal end of the catheter and a relatively large distance from the proximal end of the catheter. While the present invention is described herein in terms of certain preferred embodiments, those skilled in the art will recognize that various modifications and improvements may be made to the invention without departing from the scope thereof. Moreover, although individual features of one embodiment of the invention may be discussed herein or shown in the drawings of the one embodiment and not in other embodiments, it should be apparent that individual features of one embodiment may be combined with one or more features of another embodiment or features from a plurality of embodiments.
A balloon catheter having a multi-layered balloon which has a first layer and at least a second layer, and which has noncompliant limited radial expansion beyond the nominal diameter of the balloon. By selecting the polymeric materials forming the balloon layers, and arranging and radially expanding the multiple layers of the balloon in accordance with the invention, a balloon is provided having an improved low compliance, preferably in combination with high flexibility and softness.
0
FIELD OF THE INVENTION This invention relates to pillows utilized for travelers and more particularly to a toroidal shaped pillow which permits movement of the head of the individual during sleep without awakening the individual. BACKGROUND OF THE INVENTION It will be appreciated that a wide variety of pillows are utilized by travelers on trains, buses, airplanes, and cars to permit the individual to sleep while traveling. Prior travel pillows have tended to be flawed in terms of either being bulky or requiring permanent attachment to the seat; or fit around the neck of the individual like a collar to provide a stationary support for the head. Neck engaging pillows such as illustrated by U.S. Pat. Nos. 5,129,705; 4,776,049; 4,738,488; 4,617,691; 4,345,347; 4,285,081; 2,522,120; 2,336,707; 941,043; and 673,372 and all have as their major thrust providing a stationary support for the head by providing a neck engaging yoke. It will be appreciated that the entire purpose of these devices is to provide a stationary support for the head and therefore prevent it from moving while at the same time supporting the individual's head so that the pillow does not slip off during sleep. In use these devices actually tend to immobilize the neck and the head which makes them uncomfortable and makes sleep difficult. However, these types of devices are both uncomfortable and limit or do not allow the normal motion of the neck and head of a sleeping individual, in which the head moves from side to side or up and down as part of the natural sleep pattern. These devices are thus uncomfortable and awkward, often causing neck strain and resulting in the waking up of the individual as the head moves during the sleep pattern. There is another class of devices for inducing or promoting sleep while traveling which are characterized by the clamping of the neck or head. Such devices are illustrated by U.S. Pat. Nos. 2,582,571; 2,856,366; 4,114,948; and 4,738,488. It will be appreciated that all of these devices tend to wake up the individual when the head moves during the sleep cycle due to the restriction of the head and neck. Further, as illustrated in U.S. Pat. No. 5,205,611, this is a half clamp type structure in which the head can move in one direction but not in the other. Individuals utilizing this device may wake up either when the head moves into the stationary pillow or when the head moves in the opposite direction where there is no support. Finally, as illustrated in U.S. Pat. Nos. 4,042,278 and 4,440,443, rather than providing a tight fit around the neck or head, they engage the head loosely in the sense that the lateral supports are widely spaced apart. These devices thus do not promote sleep because they permit too much head movement and are therefore ineffective to maintain the sleep cycle. There does exist a class of support pillows such as illustrated by U.S. Pat. Nos. 5,046,205; 5,025,518; 4,768,246; and 3,848,281 which comprise apertured pillows that are adapted to fit the back of the head of an individual in which the head is positioned within the aperture. The problem with these types of devices is that when these apertured pillows are utilized as head supports, the back of the head of the individual contacts the seat back as the head projects through the aperture of the pillow. As a result, as the individual's head moves, the hair is grabbed by the seat back and the individual wakes up with the resulting tug on the hair. Another problem with such devices is that the hair of the individual may be messed up as the individual moves his head which is an annoyance factor. The friction of the back of the individual's head contacting the seat back causes the individual to awaken for two reasons. First, the individual's head does not easily rotate within the aperture of the pillow. Secondly, the pillow does not readily move with respect to the seat back due to the frictional contact of the back of the head with the seat back itself. In summary, the support devices described above are both cumbersome and tend to wake up the individual due to the inability of the support device to readily move against the seat back and due to the inability of the individual's head to move relative to the device. Also it should be noted that many of the above devices are utilized when the individual is in a supine or horizontal position and are not therefore readily suitable for seat back use. SUMMARY OF THE INVENTION In contradistinction to the above-type head pillows or support pillows, whether apertured or not, the Subject Invention is in the form of a smooth apertured pillow in which the pillow is backed with a smooth backing sheet. This provides a convenient, non-bulky, comfortable head support which is adapted to move relative to the seat back while at the same time permitting the head a friction-reducing surface over which to move within the aperture during the sleep cycle. In one embodiment, the Subject Invention is in the form of a torus with a smooth backing sheet in which the backing sheet slips easily over the seat back and forms a slippery surface over which the head can rotate within the torus. The result of placing this torus at the back of the head as a halo is that uninterrupted sleep is obtained by the individual, with the projection of the head into the aperture of the torus maintaining the torus in place at the back of the head. The uninterrupted sleep comes from the fact that the individual's head slips within the torus due to the smooth backing sheet and the smooth sidewalls of the annulus to accommodate normal rotary motions of the head during sleep. This is because there is no significant frictional retarding force against the head as it rotates. Secondly, the entire structure is adapted to slip against the seat back such that lateral and vertical motions of the head are accommodated, again with minimal friction. Because the pillow permits a reduced friction support of the head vis-a-vis the seat back, the normal motions of the head during sleep are accommodated without awakening the individual. Sleep is also promoted from the fact that the sides of the aperture, in conjunction with the portion of the device under the neck, prevent the head from falling off to the side which would eventually cause strain on the neck and wake the user. In one embodiment the torus is an inflated device, with the inflation being adjustable to accommodate different head sizes and to provide adjustment of softness by the user. Alternatively, different size toroids can be provided depending on head size; or an inner bladder can be provided within an outer bladder to provide for adjustment of the toroid to head size. It is a finding of this invention that regardless of the size of the torus vis-a-vis the individual's head, assuming a relative loose fit, the head is allowed to move during sleep and will not slip off from its position at the back of the head of the individual. What will be appreciated is that this low friction device solves a unique problem for the traveler and that is the ability to sleep in a moving vehicle and remain unawakened during normal head motion either induced by sleep patterns or induced by the motion of the vehicle itself. In summary, the smooth apertured and backed pillow is designed to allow the user to relax the neck muscles by supporting the head which enhances the user's ability to relax or sleep while traveling in a sitting position. This device also allows for lateral and vertical movement against the seat surface either while asleep or awake, thus reducing the likelihood of the device becoming dislodged or displaced. The smooth backing piece or covering is designed to allow the head to move without causing tangling of hair and reduces friction between the seat surface and the head by being interposed between the two. The backing also provides for the stability of the device by keeping it flat against the seat back when the head is angled, tilted, or moved while the head and pillow are resting against the seat surface. As mentioned above, the torus can be provided in an inflatable embodiment which additionally allows for adjustment of the softness by the user and provides a degree of portability insofar as the device can be deflated and carried deflated prior to use. Alternatively, the toroid can be constructed of solid foam and can be of different shapes as long as the resulting structure permits rotation of the head within an aperture and sliding of the entire device across the seat back. The toroidal or halo configuration allows the travel pillow to shift while the user is moving his or her head without the pillow losing its utility by becoming dislodged. By angling or tilting the head back while providing some lateral support, the subject device partially immobilizes the neck which prevents the head from angling down towards the shoulder but does not immobilize the neck. With respect to the tilting of the neck back, the apertured pillow permits the easy tilting back of the head which opens the air passageways to make for comfortable breathing and often eliminates snoring. In summary, the apertured pillow with its backing sheet allows for mobility of the neck, head, and shoulders and torso of the user while asleep. Generally such movement is necessary while sleeping in order to prevent various muscles of the neck, shoulders, and torso from stiffening up. This natural motion of the head during sleep is in part why stiffening does not occur naturally but only when the head is supported by a substantially stationary device. It will be appreciated that the user of the subject device can change position while the pillow stays in place as long as the head is not lifted substantially off the plain of the seat back. Note that it has been found that the subject pillow will not dislodge when the head naturally lifts an inch or two off the back of the seat. BRIEF DESCRIPTION OF THE DRAWINGS These and other features of the Subject Invention will be better understood taken in conjunction with the Detailed Description in conjunction with the Drawings of which: FIG. 1 is a diagrammatic illustration of the subject travel pillow illustrating the movement of an individual's head across the seat back as the individual is sleeping while sitting; FIG. 2 is a top view of the subject travel pillow illustrating an inflatable torus along with a smooth backing sheet; FIG. 3 is a bottom view of the travel pillow of FIG. 2 illustrating the positioning of the backing sheet across the entire back surface of the pillow; FIG. 4 is a top view of an individual utilizing the subject pillow, illustrating the ability of the pillow to slip laterally over a seat back; FIG. 5 is a top view of an individual using the subject pillow, illustrating the ability of the individual to easily rotate his head within the aperture of the subject travel pillow during sleep patterns; FIG. 6 is a cross sectional view of the pillow of FIG. 2 illustrating the integral backing sheet and the attachment thereto; FIG. 7 is a diagrammatic illustration of the pillow of FIG. 2 in place as a halo at the back of the head of an individual; FIG. 8 is a diagrammatic representation of the oval shaped cross section of the pillow of FIG. 6 which is produced with flat disks of elastomeric material when the pillow is inflated; FIG. 9 is an exploded view of frustoconical shaped disks for use in place of the flat disks used to manufacture the pillow of FIG. 6; and, FIG. 10 is a diagrammatic representation of a pillow manufactured utilizing frustoconical disks in which the resulting inflated torus has a circular, as opposed to oval, cross section to provide for a more steep tangent line and thus increased lateral support for the head of an individual. DETAILED DESCRIPTION Referring now to FIG. 1, an individual 10 is illustrated seated in a chair 12 having a seat back 14 and arms 16. The individual's head is illustrated at 20 which moves as illustrated by dotted outline 22 during normal sleep patterns as illustrated by arrow 24. Of course the individual can also slide up and down in the chair during sleep periods. It will be appreciated that during sleep the individual's head does not remain stationary, but moves relative to the seat back laterally and vertically. If the head is unsupported, the hair of the individual becomes entangled in the seat back which causes the individual to wake up under normal circumstances. Additionally, the seat back does not in and of itself provide any lateral head support such that as the individual nods off, the head goes to the side and falls forward which wakes the individual. Moreover, the individual is awakened by the stress of the neck muscles as the head moves. It is for this reason that pillows have been provided. As mentioned hereinabove, it was thought that by completely immobilizing the head, the pillow would not drop away from the individual, while still providing head support. More importantly, it was thought by providing a stationary support for the head, not only would the pillows stay in place, but also appropriate sleep would be induced. It is the finding of this invention that providing a stationary support for the head is to be avoided in order to induce sleep or to maintain a sleep pattern once it has been induced. It is a further finding of this invention, and as illustrated in FIG. 2, that through the utilization of the toroidally shaped and backed pillow 30 having an aperture 31 and a smooth backing sheet 32, the head can easily slip across the back of the chair illustrated in FIG. 1 without awakening the individual. The reason for this is that the pillow of FIG. 2, having a smooth backing sheet, slips across the seat back as will be described in connection with FIGS. 4 and 5. It is also important that the individual's head be able to rotate within the pillow aperture, and it is for this reason that the apertured pillow of FIG. 2 is provided with smooth aperture side walls and with the smooth backing sheet or diaphragm 32 which, in one embodiment, is integrally attached as illustrated at 34. In one embodiment, the pillow is in the form of a torus and is inflated in one embodiment through the utilization of a valve 36 which is sealable after inflation. Referring to FIG. 3, the toroidally shaped pillow of FIG. 2 is illustrated in which it can be seen that backing sheet 32 extends across the entire bottom of the torus and is adapted to coact with the seat back to provide for a low friction engagement between the two. Referring now to FIG. 4, it can be seen that the toroidally shaped pillow is permitted to move laterally in the direction illustrated by arrows 40 because the smooth backing sheet engages the surface 42 of seat back 14 to provide low friction engagement. It will be appreciated that while in use, the pillow may also move vertically with equal ease. The result is that lateral and vertical motion is permitted due to the reduced friction. Referring now to FIG. 5, rotation of head 20 illustrated by arrows 44 and 46 is accommodated within the aperture of the toroid such that the back portion of the head 48 is permitted to rotate against the smooth inner surface of backing 32. It will also be appreciated that the sides of the head contact the smooth inner surfaces of the toroid in a low friction engagement such that the head can easily move in the directions shown during the normal sleep process. In order to provide the low friction environment and as illustrated in FIG. 6, toroid 30 may be formed by two elastomeric disks, in one embodiment a polyvinyl or rubber material as illustrated at 52 and 54, with the disks being sealed together along a welded seam 56. When these two disks are so joined and air is introduced at valve 36, the toroid takes the shape shown. Alternatively the shape can be oval or even rectilinear. As can also be seen, backing 32 is joined at the side of the torus through the welding of this backing at seam 56 such that the backing stretches across the bottom of the inflated torus. It will be appreciated that the materials utilized are adapted to have surfaces that permit the slippage of the device across the seat back, whatever the material of the seat back may be, and also slippage of the head within the aperture of the pillow. Referring now to FIG. 7, it will be seen that toroidally shaped pillow 30 is adapted to be positioned at the back of individual 20's head when in use. It is the positioning of the pillow in the manner of a halo which provides lateral support to the head of the individual during sleep, with the pillow providing the usual comfort features of a pillow in terms of non-restricting support. Referring now to FIG. 8, it has been found that torus 30 when formed with identically apertured disks and a backing sheet of equal diameter, produces a torus having a cross section which, instead of being circular, is oval as illustrated at 60, when the torus is inflated. In certain circumstances it has been found that an oval slope of the torus is insufficient to provide adequate lateral support for the back of the head because the slope at a tangent 64 to the surface 66 of the torus at a point 68 is too shallow. Were the cross-section to be circular as illustrated at dotted line 70, then slope 64' would be steeper and thus give greater lateral support. Referring now to FIG. 9, if the two disks utilized to form the torus of FIG. 6 were to be frustoconical in nature as illustrated by shape 80 and are centrally apertured as illustrated at 82, then assuming the joining of these frustoconical disks at their peripheries 84 and the inner edges 86 of the annuli, then as shown in FIG. 10 the final cross section 90 of the torus 30 is more circular such that a tangent 94 to surface 96 of the torus at point 98 is sufficiently steep to provide greater lateral support for the head of the user. In summary by utilizing frustoconically shaped disks or sheets, the cross section of the torus when inflated can be made more circular. Having above indicated a preferred embodiment of the present invention, it will occur to those skilled in the art that modifications and alternatives can be practiced within the spirit of the invention. It is accordingly intended to define the scope of the invention only as indicated in the following claims.
A travel pillow is provided in the form of a torus which is inflated and which has an integral bottom backing member adapted to coact with the seat back of a chair in a plane, train, bus, or automobile in which sleep is promoted regardless of movement of the individual's head during sleep periods because the pillow permits both rotation of the head within the torus during sleep and also movement of the pillow laterally and vertically as it slips against the seat back during natural sleep movements.
0
CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of application Ser. No. 09/544,904 filed Apr. 7, 2000 which claims the benefit of provisional application 60/128,209 filed Apr. 7, 1999. BACKGROUND OF THE INVENTION [0002] The invention relates in general to movable barrier operators and in particular to movable barrier operators such as garage door operators or gate operators which include passive infrared detectors associated with them for detecting the presence of a person or other high temperature object for controlling a function of the movable barrier operator such as illumination. [0003] It has been known to use pyroelectric infrared detectors or passive infrared (PIR) detectors for the detection of a person in a particular vicinity. For instance, it is well known that pyroelectric infrared detectors can be used in combination with illumination lamps, carriage lamps, spot lamps and the like to form a low cost home security system. The pyroelectric infrared detector typically has a plurality of segments. One or more of the segments may be actuated by infrared radiation focused thereon by a Fresnel lens positioned in front of the PIR detector. The pyroelectric detector provides an output signal when a change occurs in the potential level between one element and another element in the array. Such an infrared detected voltage change indicates that a warm object radiating infrared radiation, typically a person, is moving with respect to the detector. The detectors to provide output signals upon receiving infrared radiation in about the ten micron wavelength range. The micron infrared radiation is generated by a body having a temperature of about 90° F., around the temperature of a human body (98.6° F.). [0004] It is also known that garage door operators or movable barrier operators can include a passive infrared detector associated with the head unit of the garage door operator. The passive infrared detector, however, needed some type of aiming or alignment mechanism associated with it so that it could be thermally responsive to at least part of the garage interior. The detectors were connected so that upon receiving infrared energy from a moving thermal source, they would cause a light associated with the garage door operator to be illuminated. [0005] It was known in the past to use timers associated with such systems so that if there were no further thermal signal, the light would be shut off after a predetermined period. Such units were expensive as the passive infrared detector had to be built into the head unit of the garage door operator. Also, the prior PIR detectors were fragile. During mounting of the head unit to the ceiling of the garage a collision with the aiming device associated with the passive infrared detector might damage them. The ability to aim the detection reliably was deficient, sometimes leaving blank or dead spots in the infrared coverage. [0006] Still other operators using pivoting head infrared detectors required that the detector be retrofitted into the middle of the output circuit of a conventional garage door operator. This would have to have been done by garage door operator service personnel as it would likely involve cutting traces on a printed circuit board or the like. Unauthorized alteration of the circuit board by a consumer might entail loss of warranty coverage of the garage door operator or even cause safety problems. [0007] What is needed then is a passive infrared detector for controlling illumination from a garage door operator which could be quickly and easily retrofitted to existing garage door operators with a minimum of trouble and without voiding the warranty. SUMMARY OF THE INVENTION [0008] A passive infrared detector for a garage door operator includes a passive infrared detector section connected to a comparator for generating a signal when a moving thermal or infrared source signal is detected by the passive infrared detector. The signal is fed to a microcontroller. Both the infrared detector and the comparator and the microcontroller are contained in a wall control unit. The wall control unit has a plurality of switches which would normally be used to control the functioning of the garage door operator and are connected in conventional fashion thereto. [0009] The PIR detector is included with the switches for opening the garage door, closing the garage door and causing a lamp to be illuminated. The microcontroller also is connected to an illumination detection circuit, which might typically comprise a cadmium sulphide (CdS) element which is responsive to visible light. The CdS element supplies an illumination signal to an ambient light comparator which in turn supplies an illuminator level signal to the microcontroller. The microcontroller also controls a setpoint signal fed to the comparator. The setpoint signal may be adjusted by the microcontroller according to the desired trip point for the ambient illumination level. [0010] The microcontroller also communicates over the lines carrying the normal wall control switch signals with a microcontroller in a head unit of the garage door operator. The wall control microcontroller can interrogate the garage door operator head unit with a request for information. If the garage door operator head unit is a conventional unit, no reply will come back and the wall control microcontroller will assume that a conventional garage door operator head is being employed. In the event that a signal comes back in the form of a data frame which includes a flag that is related to whether the light has been commanded to turn on, the microcontroller can then respond and determine in regard to the status of the infrared detector and the ambient light whether the light should stay on or be turned off. [0011] In the event that a conventional garage door operator head is used, the microcontroller can, in effect, create a feedback loop with the head unit by sending a light toggling signal to the microcontroller in the head unit commanding it to change the light state. If the light turns on, the increase in illumination is detected by the cadmium sulphide sensor and so signaled to the microcontroller head allowing the light to stay on. If, in the alternative, the light is turned off and the drop in light output is detected by the cadmium sulphide detector, the wall control microcontroller then retoggles the light, switching it back on to cause the light to stay on for a full time period allotted to it, usually two-and-one-half to four-and-one-half minutes. [0012] It is a principal aspect of the present invention to provide a quickly and easily retrofitted passive infrared detector for controlling the illumination of a garage door operator through conventional signaling channels. [0013] It is another aspect of the instant invention to provide a garage door operator having a passive infrared detector which passive infrared detector can-control a variety of garage door operators. [0014] Other aspects and advantages of the present invention will become obvious to one of ordinary skill in the art upon a perusal of the following specification and claims in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0015] [0015]FIG. 1 is a perspective view of a garage including a movable barrier operator, specifically a garage door operator, having associated with it a passive infrared detector in a wall control unit and embodying the present invention; [0016] [0016]FIG. 2 is a block diagram showing the relationship between major electrical systems of a portion of the garage door operator shown in FIG. 1; [0017] FIGS. 3 A-C are schematic diagrams of a portion of the electrical system shown in FIG. 2; [0018] [0018]FIG. 4 is a schematic diagram of the wall control including the passive infrared detector; [0019] [0019]FIG. 5 is a perspective view of the wall control; [0020] [0020]FIG. 6 is a front elevational view of the wall control shown in FIG. 6; [0021] [0021]FIG. 7 is a side view of the wall control shown in FIG. 6; [0022] [0022]FIG. 8 is a rear elevational view of the wall control shown in FIG. 6; [0023] [0023]FIG. 9 is a side view, shown in cross section, of the wall control in FIG. 7; [0024] [0024]FIG. 10 is a plan view, shown in cross section, of the wall control; [0025] [0025]FIG. 11 is a partially exploded perspective view of the wall control shown in FIG. 5; and [0026] FIGS. 12 A-H are flow charts showing details of a program flow controlling the operation of a microcontroller contained within the wall control as shown in FIGS. 3 A-C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0027] Referring now to drawings and especially to FIG. 1, a movable barrier operator embodying the present invention is shown therein and generally identified by reference numeral 10 . The movable barrier operator, in this embodiment a garage door operator 10 , is positioned within a garage 12 . More specifically, it is mounted to a ceiling 14 of the garage 12 for operation, in this embodiment, of a multipanel garage door 16 . The multipanel garage door 16 includes a plurality of rollers 18 rotatably confined within a pair of tracks 20 positioned adjacent to and on opposite sides of an opening 22 for the garage door 16 . [0028] The garage door operator 10 also includes a head unit 24 for providing motion to the garage door 16 via a rail assembly 26 . The rail assembly 26 includes a trolley 28 for releasable connection of the head unit 24 to the garage door 16 via an arm 30 . The arm 30 is connected to an upper portion 32 of the garage door 16 for opening and closing it. The trolley 28 is connected to an endless chain to be driven thereby. The chain is driven by a sprocket in the head unit 24 . The sprocket acts as a power takeoff for an electric motor located in the head unit 24 . [0029] The head unit 24 includes a radio frequency receiver 50 , as may best be seen in FIG. 2, having an antenna 52 associated with it for receiving coded radio frequency transmissions from one or more radio transmitters 53 which may include portable or keyfob transmitters or keypad transmitters. The radio receiver 50 is connected via a line 54 to a microcontroller 56 which interprets signals from the radio receiver 50 as code commands to control other portions of the garage door operator 10 . [0030] A wall control unit 60 embodying the present invention, as will be seen in more detail hereafter, communicates over a line 62 with the head unit microcontroller 56 to effect control of a garage door operator motor 70 and a light 72 via relay logic 74 connected to the microcontroller 56 . The entire head unit 24 is powered from a power supply 76 . In addition, the garage door operator 10 includes an obstacle detector 78 which optically or via an infrared pulsed beam detects when the garage door opening 22 is blocked and signals the microcontroller 56 of the blockage. The microcontroller 56 then causes a reversal or opening of the door 16 . In addition, a position indicator 80 indicates to the head unit microcontroller 56 , through at least part of the travel of the door 16 , the door position so that the microcontroller 56 can control the close position and the open position of the door 16 accurately. FIGS. 3 A-C are schematic diagrams of a portion of the electrical system shown in FIG. 2. [0031] The wall control 60 , as may best be seen in FIG. 4, includes a passive infrared sensor 100 having an output line 102 connected to a differential amplifier 104 . The differential amplifier 104 feeds a pair of comparators 106 and 108 coupled to a wall control microcontroller 110 , in this embodiment a Microchip PIC 16505. The sensor 100 changing signals from the comparators when the infrared illumination changes at the passive infrared sensor 100 . The microcontroller 110 provides an output at line 112 to the line 62 , which is connected to the microcontroller in the GDO head. Also associated with the wall control is a momentary contact light switch 120 , a door control switch 122 , a vacation switch 124 , and an auto-manual select switch 126 . The light switch 120 is connected through a capacitor 130 to other portions of the wall control 60 . The vacation switch 124 is connected through a capacitor 132 to the wall control 60 . The capacitor 132 has a different value than the capacitor 130 . The wall control 60 controls the microcontroller 56 through its switches by the effective pulse width or charging time required when a respective switch closes as governed by its associated capacitor or by the direct connection, as is set forth for the door control switch 122 . [0032] In addition, an ambient light sensor 140 is provided connected in a voltage divider circuit having a variable resistance 134 which feeds a comparator 150 which supplies an ambient light level signal over a line 152 to the microcontroller 110 . [0033] In addition, the microcontroller 110 supplies a setpoint signal on a line 160 back to the comparator 150 so that the microcontroller 110 , through the use of pulse width modulation, can control the setpoint of the light level comparator 150 to determine the point where the ambient light comparator 150 trips and thereby determine the ambient light illumination level. FIGS. 5 - 11 are various views of the wall control 60 discussed above. FIGS. 12 A-H are flow charts showing details of a program flow controlling the apparatus of microcontroller 56 contained within the wall control 60 as shown in FIGS. 3 A-C. [0034] As may best be seen in FIG. 12 when the processor or microcontroller 110 powers up ports and outputs are set as well as the timer in a step 500 at which point a main loop is entered and the timer is read in a step 502 . A test is made to determine if 10 milliseconds have elapsed in step 504 if they have not, control is transferred back to step 502 . If they have, the pulse width modulation cycle is cleared in a step 506 in order to start the pulse width modulation to govern the setpoint for the illumination. In step 508 , the pulse width modulation output is turned on and the pulse width modulation counter is cleared. In step 510 , the pulse width modulation counter is incremented and a test is made to determine whether the pulse width modulation counter is equal to the pulse width modulation value in a step 512 . If it is not, control is transferred to step 510 . If it is, control is transferred to a step 514 where the pulse width modulator has the counter cleared and is turned off and the pulse width modulation value is output. Followed by a step 516 where the pulse width modulation counter is incremented and a test is made to determine whether the value of the pulse width modulation counter is equal to pwm rem in a step 518 . If it is not, control is transferred back to step 516 . [0035] If it is, as may best be seen in FIG. 12B, the pulse width modulation cycle is incremented in a step 520 , and a test is made in step 522 to determine whether it is equal to six. If it is not, control is transferred back to step 508 to restart the pulse width modulation. If it is, the pulse width modulator is turned off in step 526 and a read comparison is made in a step 530 . If the read comparator is high, the plunge counter is decremented in a step 532 , and the increment counter is incremented in a step 534 . In a step 536 , the value of the incremented counter is tested to determine whether it is greater than 10 . If it is, the counter is cleared and a step 538 . If it is not, control is transferred to a step 540 where the pulse width remainder value is set equal to pulse width modulation value compliment. [0036] In the event that the value of the read comparison step 530 yields a low value, a leap counter is cleared in a step 550 and a decrement counter is incremented in a step 552 . A test is made in a step 554 to determine whether the decrement counter value is greater than 10 . If it is not, control is passed to step 540 . If it is, the decrement counter is cleared in a step 556 and a test is made to determine whether the pulse width modulation value is zero in a step 560 . If it is zero, control is transferred to step 540 . If it is not, the pulse width modulation value is decremented, the plunge counter is incremented in a step 562 . In a step 564 , the plunge counter is tested to determine whether it is greater than 12 . If it is, the pulse width modulation value is tested for whether it is less than 20 in a step 566 . If it is not, the pulse width modulation value is set equal to the pulse width modulation value minus nine in a step 568 and control is transferred to the step 540 . [0037] Upon exiting the step 540 , as may best be seen in FIG. 12C, a test step 570 is entered to determine whether the light on state has been set by the head unit of the movable barrier operator. If it is not, a test is made in a step 522 to determine whether the awake timer is active. If the awake timer is active, control is transferred to a step 574 causing a 16-bit counter timer to be incremented and to blank any bit counter. If the timer is not active, control is transferred to determine whether the blank timer is active in a step 576 . If it is, control is transferred to step 574 . If it is not, control is transferred to a test step 578 to determine whether checking is active. If checking is active, the checking counter is incremented in the step 530 and a test is made to determine whether the value of the checking counter is equal to one second in a step 582 . If it is not, control is transferred to a test step 600 , as shown in FIG. 12D. If it is, a test is made to determine whether the light-on flag is on or not in a step 602 . If it is on, a test is made in a step 604 to determine whether the present pulse width modulation value is equal to the stored modulation value. If it is indicated to be lighter, control is transferred to a step 606 to clear checking. If it is indicated to be dimmer, control is transferred to a step 608 causing the work light signal to e toggled by the wall control over the lines connected to the head unit. If the light-on value flag is indicated to be off, a test is made in a step 610 to determine whether the present pulse width modulation value is equal to the stored value. If it's indicated to be dimmer, control is transferred to the step 606 . If it's indicated to be lighter, step 612 turns on the work light toggle to flip the light state and transfers control to step 606 . [0038] Once the light has been toggled, a test is made in step 600 , as shown in FIG. 12D, to determine whether the awake flag has been set. If it has, a test is made in a step 620 to determine whether the work light toggle is active. If it is, the pulse width value is incremented in a step 622 , and a test is made to determine whether the pulse width count is equal to 20 (which is equivalent to 200 milliseconds) in a step 624 . If it is not, the work light is toggled off in a step 626 . In the event that the awake flag has not been set, a test is made in a step 630 to determine whether the RC time constant for the power supply has expired. In other words, has the power been kept high for more than 1.5 minutes as tested for in step 630 . If it has not, control is transferred back to the main loop in FIG. 12A. If it is, the awake value is set and the timer is cleared in the step 634 , and control is transferred back to the main loop. In the event that the time constant has expired in step 630 , the awake flag is cleared and the counts are set high in the step 636 after which control is transferred back to the main loop. After the work light has been toggled and the step 626 , a step is made in a step 660 , as may best be seen in FIG. 12E to determine if the blank timer is active. If it is, it is checked. If it is not, a test is made to determine whether there is indicated to be activity from the passive infrared input indicating a change in a step 662 . If not, a quiet state is entered. If the PIR has been indicated to be active, a second test is made to determine whether the PIR still indicates that it is changing to indicate that a false signal has not been received. If it is, a test is made to determine whether the work light is on within the garage. If the work light is on, control is transferred back to the main loop. If the work light is indicated not to be on, a test is made to determine whether the pulse width value is greater than 128 , in other words, whether the garage is indicated to be bright or dim. If it is indicated to be bright, indicating it's illuminated control is transferred back to the main loop. If it's indicated to be dim, control is transferred to the test step 680 , as may best be seen in FIG. 12G to determine whether two-and-one-half seconds had elapsed. If they have not, the blank timer is turned off in the step 682 . If they have, a test is made in the step 684 to determine whether the light-on state has been set. If it has, a test is made in a step 686 to determine whether six minutes have passed. If they have, the timer is cleared, the light-on flag is cleared, the blank flag is set, and an attempt is made to read the light state from the head unit via serial communication in a step 688 . A test is made in a step 690 to determine whether the serial communication has been successful. If it has, a test is then made in a step 692 to determine whether the light-on flag has been returned from the head unit to the wall control. If it has, indicating the light has been set on, the toggle output is set in a step 694 . If it has not, control has been transferred to the main loop. If serial communication has failed, as tested for in step 690 , the toggle output is set in a step 700 , pulse width modulated value is stored in a step 702 , and checking is set in a step 704 prior to transfer back to the main loop. [0039] In order to respond to the query function, which is used to interpret the word sent back by the head unit, as may best be seen in FIG. 12H. In a step 750 , there is a delay until a key reading pulse in a step 752 and a timer is reset in a step 754 . A 500 microsecond delay is waited for in a step 756 . A series of delays are used to generate an on-off output code of varying pulse widths followed by a 100 microsecond delay in a step 758 . A test is then made in a step 760 to determine whether the wall control input pin is low. If it is not, the test is remade. If it is, control is transferred to a step 762 to set a flag indicating serial communication is successful. A time value is set is a step 766 and status is read in a step 768 . A test is made in step 770 to determine whether the serial is okay and in a test 772 a brake signal is tested for and sent. [0040] In order to respond to the query light, as is shown in FIG. 12F, in a step 800 the query light is called. A test is made in a step 802 to determine whether it was readable by a serial communication with the head. If it was, a test is made in a step 804 to determine whether the light was on. If it was, control is transferred back to the main loop. If it was not, the toggle output is set to indicate that the state was light-on in step 806 to force the light to be on. [0041] In the event that the serial communication was not readable, the toggle output state was set, it's light on in step 810 , pulse width modulation value restored in the step 812 , and the checking flag is set in the step 814 . Attached is an Appendix consisting of pages A-1 to A-12 which comprises a listing of the software executing on the microcontroller 110 . [0042] While there has been illustrated and described a particular embodiment 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 wall control unit for a movable barrier operator sends baseband signals over a wire connection to a head unit of a movable barrier operator to command the movable barrier to perform barrier operator functions. The wall control unit has a wall control unit port for connection to the wire connection. A first switch sends a barrier command signal to the head unit commanding the head unit to open or close a movable barrier. A second switch commands the head unit to provide energization to a light source. An infrared detector causes a command signal to be sent to the head unit to control the illumination state of the light source.
4
BACKGROUND OF THE INVENTION This invention relates generally to couplings and, more particularly, to an improved insulated coupling for a television tuner shaft or the like. Several techniques for providing an insulated shaft coupling are known. The most common technique utilizes a two section metal shaft having an axially extending chamber formed in the end of one of the sections and an axially extending reduced diameter section formed in the other section. An insulating bushing is inserted into the chamber, and the reduced diameter portion of the other metal section is pressed into the bushing which serves to hold the two sections together with a press fit. Although this system provides a way to insulate two sections of a metal shaft, the system necessitates a compromise between the insulating qualities and the mechanical strength of the coupling. For example, when such a prior art system is employed in a television tuner shaft having a nominal 0.250 inch diameter, the reduced diameter section of the mating section must be reduced to approximately 0.150 inch to permit the walls of the insulating bushing to be sufficiently thick to provide the necessary insulating properties. Unfortunately, reducing the diameter of the shaft within the coupling reduces the mechanical strength of the shaft and results in bending and breakage problems occurring at the coupling, particularly with long shafts of the type commonly used in console television sets. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved insulated coupling. It is another object of the present invention to provide an insulated shaft coupling that has greater mechanical strength and better insulating properties than prior art shafts. In accordance with a preferred embodiment of the invention, an axially extending chamber is formed in one end of each of the two metal shaft sections to be joined. A flanged insulating bushing is pressed into each of the chambers and a hardened steel pin is pressed into the two insulating bushings in order to hold the two sections of the shaft together with the flanges of the insulating bushings abutting each other. Because of the above structure provides a doubly insulated coupling, with insulation isolating the pin from both of the shaft sections, the thickness of the walls of the two bushings may be reduced to permit a larger diameter pin to be used to increase mechanical strength without sacrificing the insulating properties of the coupling. Furthermore, the pin may be fabricated from hardened steel or the like, which is substantially stronger than the shaft material, to further increase the mechanical strength of the coupling or to permit a smaller diameter pin to be used to further improve the insulating properties of the coupling without sacrificing mechanical strength. The above and other objects and advantages of the present invention will be readily apparent from the following detailed description and attached drawing, wherein: FIG. 1 is a simplified perspective view of a television tuner utilizing the insulated coupling according to the invention; FIG. 2 is an exploded perspective view of the insulated coupling according to the invention; FIG. 3 is a side sectional view of the insulated coupling according to the invention; FIG. 4 is a cross sectional end view of the insulated coupling taken along the line 4--4 of FIG. 3; FIG. 5 is a cross sectional end view taken along line 5--5 of FIG. 3; and FIG. 6 is a cross sectional side view of an alternative embodiment of the insulated coupling according to the invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawing, with particular reference to FIG. 1, there is shown a television tuner 10 having a selector shaft 12 protruding therefrom. The selector shaft 12 comprises a first section 12a extending outwardly from the tuner 10 and a second section 12b coupled to the section 12a by means of an insulated coupling 14. The insulated coupling 14 serves to isolate the tuner 10 from the shaft section 12b to protect the user from electrical shock in the event that the tuner is used in conjunction with a live chassis receiver and the power plug is inserted such that the potential of the chassis is at line potential. The shaft sections 12a and 12b (FIGS. 2-5) are fabricated from standard tuner shaft stock, and are typically 0.250 inch in diameter. Splined chambers 16a and 16b are formed in one end of each of the respective shaft sections 12a and 12b. The splined chambers 16a and 16b are typically formed, for example, by drilling an axial hole to a depth of 0.625 inch and forming a 16-point internal spline 18a and 18b in each of the respective chambers 16a and 16b. Two bushings 20a and 20b are fabricated from an insulating material such as nylon. Each of the bushings 20a and 20b has a respective body portion 22a and 22b, and a respective flange portion 24a and 24b. The outside diameters of the body portions 22a and 22b are selected to provide a press fit with the respective chambers 16a and 16b. The outside diameters of the flanges 24a and 24b are substantially equal to the outside diameter of the shaft sections 12a and 12b. The diameter of the flanges 24a and 24b may be smaller than the diameter of the shaft sections 12a and 12b, but preferably not larger, as this may prevent the shaft from being fully inserted into relatively small holes of the type found in control knobs, mounting brackets, etc. Axial openings 26a and 26b are formed in each of the respective bushings 20a and 20b for receiving a knurled coupling pin 28 which may be fabricated from any strong material such as hardened carbon steel. The pin 28 has a knurled section 30 and a pair of reduced diameter end sections 32 and 34. The pin in the illustrated embodiment has a 12-point knurl, but any number of points, consistent with good design practice, may be used. The outside diameters of the reduced diameter end sections are smaller than the inside diameters of the openings 26a and 26b, and serve to center the pin 28 in the bushings 20a and 20b during assembly. The outside diameter of the knurled section 30 is larger than the inside diameter of the openings 26a and 26b and provides a press fit between the pin 28 and the bushings 20a and 20b. As shown in FIG. 4, the bushing 20a (and similarly the bushing 20b) is deformed by the spline 18a and the knurled section 30 so that the outside of body 22a conforms to the shape of the spline 18a and the axial opening 26a is deformed to correspond to the shape of the knurled section 30 of the pin 28. Such a deformation causes an extremely tight coupling between the pin 28 and the two shaft sections 12a and 12b. Spaces between the bottom of the shaft chambers 16a and 16b and the ends of the respective bushings 20a and 20b have been shown in the drawings, but it is desirable to minimize these spaces or to provide protrusions at the ends of the bushings 20a and 20b to prevent the bushings 20a and 20b from being excessively stretched when the pin 28 is inserted. In addition, the spaces between the ends of the pin 28 and the bottoms of the bushings 20a and 20b should be minimized to prevent the pin 28 from being inserted substantially deeper into one of the bushings 20a and 20b than the other. In the embodiment described above, the two flanges 24a and 24b serve to separate the ends of the shaft sections 12a and 12b to prevent the two shaft sections 12a and 12b from physically contacting each other. The body portions 22a and 22b serve to insulate the shaft section 12a from the pin 28 and the pin 28 from the shaft section 12b, thereby providing two insulating members connected electrically in series and permitting thinner walls to be used for the body portions 22a and 22b to provide a stronger structure without sacrificing electrical isolation. In this embodiment, each of the bushings 20a and 20b is provided with a flange so that identical bushings may be used as the bushings 20a and 20b, thereby reducing the number of different parts required. However, it is not necessary to make the structure symmetrical, and only one of the bushings need to be provided with a flange, provided the flange is sufficiently thick (in the axial direction) to prevent electrical arcing between the two shaft sections 12 a and 12b. Such an embodiment is shown in FIG. 6. In the embodiment shown in FIG. 6, two shaft sections 112a and 112b, analogous to the shaft sections 12a and 12b, are joined by pin 128. Instead of using two symmetrical bushings, such as the bushings 20a and 20b described in the previous embodiment, insulation is provided by utilizing a flanged bushing 130 and an unflanged bushing 132. The flanged bushing 130 is similar to the bushings 20a and 20b and has a body portion 134 and a flange portion 136. If necessary, the flange portion 136 may be made thicker (i.e. having an increased longitudinal dimension) than the flange portions 24a and 24b to provide the desired isolation. The bushing 132 has a body portion 138 similar to the body portions 22a and 22b, but no flange portion. As in the case of the previous embodiment, the diameters of the pin 128 and the bushings 130 and 132 are selected to provide a press fit between the pin 128 and the bushings 130 and 132, and between the bushings 130 and 132 and the shaft sections 112a and 112b. In another embodiment (not illustrated), two flangeless bushings similar to the bushing 132 may be used, and an insulating washer may be used in place of the flange 136 to separate the two shaft sections. Alternatively, the coupling pin may be encapsulated in an insulating material, and a washer (either separate or integrally formed with the encapsulation) may be used to keep the two shaft sections separated. While certain preferred embodiments of the invention have been described by way of illustration, many modifications will occur to those skilled in the art; it will be understood, of course, that it is not desired that the invention be limited thereto, since modifications may be made, and it is, therefore, comtemplated by the appended claims to cover any such modifications as fall within the true scope and spirit of the invention.
An insulated coupling usable with a television tuner shaft or the like for electrically isolating the tuner shaft from the chassis of the television receiver includes a pair of flanged insulating bushings pressed into axially extending chambers formed in the ends of two coupled sections of the tuner shaft. A knurled pin fabricated from hardened steel or other strong material is pressed into the two bushings to hold the two sections of the shaft together with the two flanges of the bushings abutting to form an insulated section between the two coupled sections of the shaft.
8
This Patent Application claims priority from U.S. Provisional Patent Application No. 60/523,377, filed on Nov. 18, 2003, and entitled “Building Protection Structures and Methods for Making and Using the Protection Structures.” The contents of this provisional application are hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to form molded structures, and more particularly, to the manufacturer, installation and use of molded building component structures. 2. Description of the Related Art In current construction practice, there are two known and common methods of building outdoor decks and balconies, to be used as part of building structure. The first is the classic redwood deck, which allows rain water to leak down between gaps in the planks. The second is the moisture resistant tile or liquid plastic coating deck. Most people are familiar with redwood decks. Floor joists are attached to the house either cantilevered from the second floor, or built on beams and posts for a larger deck. The 2×6 (inch) dimensional redwood boards are nailed down flat perpendicular to the joists with a ¼ inch gap between the planks. This has been a very popular and attractive decking system. One downside to this system is that redwood cracks and ages, and redwood is becoming more scarce and expensive. Recently, firms like Trex™ have addressed these problems by extruding synthetic decking planks, that are similar in shape and size to the redwood 2×6 planks. They can be sawed and drilled almost as easily as wood. By mixing plastic and sawdust these products are longer lasting than redwood, wear and look better than redwood over the years and claim to be termite and mold resistant. The problem that both redwood and synthetic wood decks have is that they are not rain-proof. When it rains, the water drops down between the gaps of the boards, hitting the ground below and wetting the joists and beams. Over time this rots the structural wood, eventually requiring rebuilding of the deck, or worse, complete structural collapse, killing in many cases those on the deck at the time. The other drawback is that no habitable space can be built below. A watertight decking system is required for this application. There has been a long history of watertight decks and balconies built over the years. The most common way is to build a slightly sloping hot mopped deck using modified bitumen and galvanized metal flashings, much the same way a flat roof is done by roofing contractors. The difference is that a walking deck must be built much stronger than a roof, and must have a hard, slip resistant surface over the asphalt coating. Typically this is done like a tile shower pan. Over the hot mop, ¾′ of grout is placed, properly sloped for drainage, then tile or stone or pavers are set, then grouted, and finally weather sealed. Finally flashing must be installed and checked to avoid leaks into the house during rain storms. The hot mopped and tiled exterior rain resistant deck is a very expensive and complex endeavor, involving 4 or 5 building trades, spending weeks on each deck. And worse, the deck is the most vulnerable part of the house to the freeze thaw cycle, the expansion and contraction between hot and cold weather. During hot weather the deck may expand cracking the asphalt coating underneath which may have become brittle over time. In the cold weather the tiles may pull away from the house, allowing water infiltration. Then when it rains, water may seep below the tile and migrate to some other location where the asphalt is cracked, causing leaks down into the sheet rock ceiling below. When the homeowner calls out the contractor it generally happens that the real point of leakage is hidden from view from the deck above. Many times the only fix is to tear up the expensive tile and hot mop and do it all again. In part to address this problem of the invisible leak, as well as the high cost of the installation of rain-proof decks, many liquid epoxy and plastic walkable coatings have been developed over the past 20 years. Firms like Dex-O-Tex sell liquid coatings installed by factory-approved installers, in several coats and with special flashings and fiberglass reinforcing. A sand finish is tossed onto the final coat for skid resistance, and different colors are offered. Durability depends on the sloping and structural strength of the exterior grade plywood on which the liquid coats are spread. A 5-coat job may take a week to complete and is still a relatively expensive and risky endeavor. These have also been leaks and liability problems in housing projects. The deck must be inspected regularly and repaired promptly to protect the habitable areas below. Therefore, what is need is a durable and reliable structure that can be used as a deck or building component, without introducing the aforementioned problems. SUMMARY OF THE INVENTION Broadly speaking, the present invention fills these needs by providing a structure that is form-molded, in one piece. The form-molded structure can take on any number of forms, as will be described below. One particular form is the form of a deck of a building. The resulting deck is defined from plastic, and when formed, defines a plastic deck shell with integral flashing. The deck shell can be installed over or up against structural framing of a building to provide moisture protection and enable human traffic, if the form is a deck. It should be appreciated that the present invention can be implemented in numerous ways, including as a method, a structure, a system, or an article of manufacturer. Several inventive embodiments of the present invention are described below. In accordance with a first aspect of the present invention, a structure for use in building construction is provided. The structure is defined by a body having a top surface, a bottom surface, and side surfaces. A flashing liner is integrally formed with the body, and the flashing liner is defined at one or more of the side surfaces of the body. The body is capable of being attached to a building structure, and the flashing liner provides a weather interface with the building structure. In accordance with a second aspect of the present invention, a deck structure to be attached to a building is provided. The deck structure has a grooved top surface, a bottom surface, and side surfaces, and the deck structure is defined from a plastic mold. A flashing liner is integrally formed from the plastic mold along with the deck structure, and the flashing liner and the deck structure define a unitary structure without connecting seams. The flashing liner is defined at one or more of the side surfaces of the deck structure. The body is capable of being attached to the building, and the flashing liner provides a weather interface with the building and the top surface providing a supporting interface for human support and traverse when the deck structure is attached to the building. In accordance with a third aspect of the present invention, a deck structure to be attached to a building is provided. The deck structure has a rough top surface, a bottom surface, and side surfaces, and the deck structure is defined from a plastic mold. A flashing liner is integrally formed from the plastic mold along with the deck structure, and the flashing liner and the deck structure define a unitary structure without connecting seams. The flashing liner is defined at one or more of the side surfaces of the deck structure, and the flashing liner is configured as an interface with the building at one of a wall or a door way of the building. The flashing liner establishing a weather tight interface between the wall or the door way of the building, and the rough top surface having grooves defined by the plastic mold. The grooves extend substantially perpendicularly away from the building, such that the grooves drive water away from the building. In accordance with a fourth aspect of the present invention, a method for making building structure is provided. The method includes defining a mold. The mold having surfaces for defining a body with a top surface, a bottom, and side surfaces, and the mold further including surfaces for defining flashing liners to be coupled to at least one of the side surfaces of the body. The method then includes filling the mold with a plastic to define a deck structure with integral flashing. The deck structure defined for supporting a human when the deck structure is attached to a building. In one embodiment, the deck is formed in the factory to the size and shape desired by the customer, and includes integral flashing, water run-off channels and a non-skid walking surface. The deck of the present invention provides a cost effective, easy and fail-safe method of installing moisture resistant decking surfaces in residential or commercial construction projects. In one embodiment, the process of making the one piece deck utilizes vacuum-formed technology, which allows the deck to be made as a seamless unitary and integral structure. The integral structure, in the decking application, will include integral flashing. The deck therefore installs easily and quickly to provide rain tight protection to structural wood and habitable space below and around the deck. By using tough and flexible polyethylene plastic, ribbed for strength and surfaced for a skid resistance, a strong and nearly indestructible walking surface is provided. By including integral flashing down over the sides of the deck and up under the building paper and stucco, leaks are eliminated. By design, potential weak spots are strengthened, and expansion and/or contraction is anticipated and allowed. The deck surface can move back and forth through temperature and humidity swings, or earthquakes. As a benefit, due to the single piece design, installation can be done in as little as one half hour per deck. This is compared to over a week for all other rain proof systems. In some markets, total material and labor cost can be as low as 10% of what is currently paid for prior art, less desirable techniques. Further, once a carpenter builds the structural deck and covers the joists with plywood, he can immediately cover the deck with a white neoprene foam, staple building paper to the lower walls, nail on the 1×2 cleats and then screw on the Deck with stainless steel screws and washers, and then tap in the plastic screw cover plugs. Compare to hot mop decks, after the carpenter frames the deck, the following sub-contractors are required: a. roofing/hot mop sub; b. sheet metal flashing sub; c. tile setter; d. sealer/painter; and e. more flashing. Liquid plastic decking subs handle most flashing themselves but the sheet metal sub usually is involved. By design, stops and guides allow the carpenter to install the deck in only one way—the right way. Should the carpenter forget a piece of building paper, he can unscrew a section until he can slip the paper in, then re-screw. Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements. FIG. 1 is a perspective view of a cantilever deck, in accordance with one embodiment of the present invention. FIG. 2 is an exploded view of the deck to be attached to a building, in accordance with one embodiment of the present invention. FIGS. 3A-3I show the deck attached to a building and integral flashing installed up against the building and detailed magnifications, in accordance with one embodiment of the present invention. FIG. 4 illustrates a recessed deck, in accordance with one embodiment of the present invention. FIG. 5 illustrates a recessed deck attached to a building, in accordance with one embodiment of the present invention. FIGS. 6 and 7 illustrate a multi-panel deck, in accordance with one embodiment of the present invention. FIGS. 8 and 9 illustrate an awning with integral flashing, in accordance with one embodiment of the present invention. FIG. 10 illustrates a fireplace roof and integral flashing, in accordance with one embodiment of the present invention. FIG. 11 illustrates a bay window roof with integral flashing, in accordance with one embodiment of the present invention. FIG. 12 illustrates a bow window roof with integral flashing, in accordance with one embodiment of the present invention. FIGS. 13-19 illustrate additional applications of a plastic molded structure for use in building construction, in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An invention is described for plastic form molded structures, which can be used in the construction of buildings. The structures can take on any number of forms, and examples of such forms are provided below. Of particular interest, a deck can be defined from a single plastic piece with integral flashing. In one example, the deck is formed in a mold which is filed with liquid plastic, and the liquid plastic is cured or allowed to cool until a hard material results. The plastic can optionally include fibers to introduce strength, and colors can be added to provide different ready to use styles. It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention. A deck system is a one piece molded plastic unit. In one embodiment, the decking surface curves up the wall and becomes flashing. The flashing is thus integral with the deck body. At a sliding door or French doors, the flashings bend down under the door sill, preventing driving rains from soaking the carpet or wood framing. The plastic used is similar to that used in pickup truck bed liners, many of which have suffered 20 years of abuse (like daily loading and unloading of bricks) in the desert sun without cracking or denting. In one specific example, the plastic material will include fibers to introduce additional strength. Examples of the plastics, without limitation, can be selected from the group consisting of one or a combination of (a) polyethylene, (b) olefin (c) olefin fibers (d) polypropylene and polyethylene, (e) polystyrene, (f) poly (vinyl chloride), and (g) polytetrafluoroethylene. In another alternative and optional embodiment, supporting framing may also be embedded in a mold so that the resulting molded plastic can have additional strength. Slotted screw holes and the inherent flexibility of the plastic make it impervious to expansion, contraction and structural movement. Ample flashing wings are designed for horizontal rains. Radiant heat can be resisted by a light gray color of the plastic, the white painted underside and the white neoprene under-layment. Direct sunlight has no deterioration effect, chemicals or animal urine will not damage surface, and moist or salt air will not damage the plastic or the stainless steel screws. In sum, the resulting form molded deck or other structure, is capable of withstanding harsh outdoor weather elements, while maintaining its serviceability to the structure. FIG. 1 is a perspective view of a cantilever deck, in accordance with one embodiment of the present invention. Made from a single piece of plastic, it is heat formed to the shape shown. The heat is used to melt the plastic used to define the deck, and the plastic is applied to a mold. The molding process can include, for example, a vacuum molded process, a form molded process, a pressure form molded process, or an injection molded process. In essence, the molding process can vary, so long as the mold can receive liquefied plastic, allow the plastic to flow into the appropriate shape, and then allow the plastic to cool until reaching a solid state. In the illustrated example, the deck 20 has a slightly sloping flat surface, sloping about 2% from back to front. Of course, the slope is optional depending on the application. The flat areas at the left and right are the guard railing attachment areas. The drainage grooves 24 also slope back to front and also act as structural ribs spaced inches apart, giving the roughen walking surface 26 strength and the ability to span imperfections in the plywood structural wood surface below. The ribs prevent buckling and tie the entire unit together. Sloping up from the back of the walking surface 26 is the back flashing 32 and to the right and left sides are the side flashings 36 . The flashings 32 / 36 facing forward have embedded grooves to define screw guide grooves 28 . The screw guide grooves 28 let the carpenter or installer know where to place the attachment screws 40 , as well as to help the screw tap into the plastic by starting it in the groove without slipping off the plastic. The screw will not be placed too close to the edge where it might break the plastic. The vertical cut guide grooves 30 in the back flashing 32 are placed to assist the installer in making the vertical cuts needed to install the patio doors and fold back that portion of the back flashing 32 . The grooves are placed at the rough opening widths of common patio doors. The grooves aids the use of a utility knife by providing a scored vertical line. The other horizontal grooves are the bending grooves 48 used when that portion of the back flashing 32 is bent back into the patio door opening. Reference should be made to the description of FIG. 3 for more information. In the front apron 39 and the side aprons 49 , are screw hole recesses 46 which have slotted expansion holes inside. After installing the stainless steel screws 40 and washers provided, screw cap plugs 42 are tapped into the recesses 46 . The caps keep water out and visually hide the screws. Drip ledges 44 are designed to keep rain water away from the structure below. Gutters, stucco or wood trim can be installed by the contractor in the space provided beneath the bottom flashing 38 . FIG. 2 shows the one-piece cantilever deck 20 floating directly above where it will be installed onto a typical wood framed house. We are looking down onto the wood framed second floor of a house under construction from the front right. Directly below the deck is the wood framed cantilever deck. Smaller floor joists 56 cantilever towards us supported by the stud wall 70 , 68 , below. The first floor studs 70 support the double top plates 68 above. The rim joist 58 of the second floor sits on the plates 68 . Note that the deck plywood 52 is 2′-4′ lower 72 than the second floor main level plywood 50 . Perpendicular to the rim 58 and sitting on the top plates 68 are the large second floor joists 60 . Plywood 62 is nailed down on the joists 60 and the second floor wall is built. The sole plate 64 and the studs 66 are shown, as well as the opening 50 for the patio door. A cantilever deck is framed by extending the deck joists 56 out past the wall below and finished of with the deck rim joist 54 . These joists 56 slope down about 2% away from the wall. Plywood 52 is nailed to the top of the joists 56 and the rim 54 . Plywood sheathing and building paper will be placed on the studs later. FIG. 3 shows the deck 20 installed on the wood framing. Building paper installed under the plastic deck is not shown for clarity. The front apron 39 and side aprons 49 are screwed using screw hole recesses 46 to the deck rim joist 54 and the deck joists 56 . The back flashing 32 and side flashings 36 are screwed to second floor studs 66 , sole plate 64 and rim joist 58 . In the patio door opening 50 , vertical cuts 76 are made in the back flashing 32 and the flashing is bent back 90 degrees along one of the bending grooves 48 and screwed down to the plywood 62 . The deck is ready for more building paper, the patio door, lathe and plaster and stucco. After the stucco is painted a guard rail can be installed directly to the top of the plastic deck, or to the deck wood framing below. Nothing else needs to be done to the plastic deck—no paint, no sealer, no surfacing. The decking can take on any number of colors, and the colors are added to the plastic as an additive, to produce the desired color shading. In the case where the rain proof deck is recessed back into the second floor, the recessed deck 78 takes the form shown. Looking at the deck from the front right, we see the drainage grooves 24 , which are also strengthening ribs, and the roughened walking surface 26 . Along the front apron 39 are the screw hole recesses 46 where the screws 40 and screw plugs 42 are installed. The back flashing 32 and side flashings 36 bend up from the walking surface. The entire deck is formed from one sheet of plastic, so it installs as one unit, and thus prevents leaks (as there are not seams). No hot mop or asphalt felt is required below the deck since it itself is rain tight. On the vertical flashings are bending grooves 48 , screw guide grooves 28 and vertical cut grooves 30 . This design allows doors to be installed anywhere on the left, right or back of the deck. Bottom flashing and drip 38 allows for a gutter or wood trim to be installed. Looking at the recessed deck 78 again from the front right, we see it installed in typical wood framing. Note that the level of the deck drops 2′-4′ from the main second floor level 72 . This helps keep blowing rain out of the house. Like we saw in FIG. 3 , the first floor studs 70 support top plates 68 which support rim joist 58 and floor joists 60 , which are taller than the deck joists (not shown). Plywood 62 covers the second floor and is under the deck. Sole plate 64 , studs 66 and the patio door opening 50 are shown. The back flashing 32 is cut 76 at each side of the patio door opening 50 and bent back 74 along the bending grooves 48 , and it is screwed 40 down to the plywood 62 . The flashing are screwed to studs 66 , plates 64 and rims 58 . The front apron 39 is screwed 40 to the rim 58 , finished with tapped in screw plug covers. FIGS. 1 through 5 illustrated the deck in its one piece configuration. Some deck projects are so large that they cannot be produced in one piece due to the size of available sheet plastic, the size of delivery trucks or the ability of the crew to efficiently and safely handle the material. FIG. 6 shows a three piece deck system that when assembled and snapped together creates the watertight deck shown in FIG. 7 . In FIG. 6 we see the roughened walking surface 26 , the structural rib drainage grooves 24 , and the side 36 and back flashing 32 . FIG. 6 shows the three different pieces of the system: the left deck section 80 , center deck section 82 and right deck section 84 . Bottom flashing 38 , drip 44 and screw hole recess 46 are shown. Special overlap snap grooves 86 are shown facing the center section 82 on the left 80 and right section 84 . FIG. 7 shows the three pieces assembled. The patio door opening 50 is shown with the cut section of the back flashing bent back 74 along a bending groove 48 and screwed 40 down Screws 40 are placed in the guide grooves 28 in the side 36 and back flashing 32 . Together, the three pieces can create a large deck that is completely water tight and three times bigger that the one piece deck. Of course, the size will depend on the application and the number of decks that are combined to form a large deck. In some commercial applications, the number of joined decks can be many, while in smaller residential projects a single deck will be sufficient. The one piece awning is very similar to the one piece deck. The main surface slopes steeper like a roof, it has ribs 88 for strength and drainage grooves 24 , but it needs no wood structural support under it. It gains its strength from the triangular shape, the ribs and the screws 40 holding the side 36 and back flashings 32 to the structural wall. The flashing has structural ribs 88 which transfers loads to the screws 40 . It is intended to be installed over doors or windows for sun or rain protection. Since the flashings go under the stucco or siding, it is intended for new construction. But, it can also be used in remodels if appropriate adjustments are made. FIG. 9 shows the optional built-in gutter 92 , which includes a hole to which a down spout can be attached. FIG. 10 provides the detailed illustration of a direct vent gas fireplace roof. The use of a direct vent fireplace is becoming more popular as municipalities are required to reduce pollution, and thus restrict the use of traditional wood burning fireplaces. Direct vent gas-only fireplaces are increasing sold with the gas vent going sideways straight out the back of the firebox. The traditional boxes are projecting into the side setbacks, but the chimneys are eliminated. As something has to cover the 2′×5′ projection so architects have been specifying matching composition or tile roof, or galvanized metal flashing. FIG. 10 shows the DV Fireplace Roof 100 installed over the box 96 with the side vent 98 . The back and side flashing 32 36 are attached with screws 40 though the screw grooves 28 . The top of the roof has structural ribs 88 and a drip 44 around the front and side aprons. There are many smaller projections in residential construction like bay and bow windows that can use rain proof preformed roof and flashing systems. Installing the plastic molded bay and bow window roofs save a lot of time and money. No rafters or plywood are needed, and the structural ribs 88 keep the roof 104 from sagging. Screw 40 the flashing 32 36 and apron on, then snap the strip screw cover 106 into the screw channel 34 , and you are done. FIG. 13 shows a parapet or free-standing stucco wall 102 . Too often no cap at all is placed on a stucco wall, only to discover years later that water has leaked down the wall through small crack in the stucco on the top of the wall. A metal cap is a better solution, but is not attractive if in a visible location such as a 36′ high stucco wall around a deck. FIG. 13 shows one piece plastic decorative caps that interlock with adjacent caps, maintaining the water seal even at the joints 86 . Four caps are offered: the end cap 110 , straight run 112 , 90 degree corner 114 , and end cap terminating into a wall 116 integral with top 32 and side flashing 36 . In this embodiment, all pieces have drips 44 . FIG. 14 is a one piece cap 118 for pilasters 102 such as pilasters that support entry gates. Screws 40 are installed into screw recesses 46 and covered with screw caps. Drip 44 accepts trim or stucco. FIG. 15 shows a railing cap 120 designed to work with the recessed deck of FIGS. 4 and 5 . FIG. 16 shows a patio cover. Similar to the 3 piece deck, the 3 piece Patio Cover spans the full length from wall to beam without any rafters or plywood, just with the strength of the ribs. FIGS. 17 , 18 and 19 illustrate a retro-deck. The retro-deck is designed to go over any size or shape existing redwood deck. Although not 100% watertight, retro-deck is a big improvement in keeping rain out from under the deck, it prevents further rotting of the joists and looks new and clean. All sections 122 are the same and they snap together at the long edges 124 . The top edges at the house side of the deck are finished with head stop 130 , and the front edge is contained by base stop 132 which has an integral drip. Stops are screwed down 40 to the existing decking 126 and joists 127 . Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present 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 equivalents of the appended claims. In the claims, elements and/or steps do not imply any particular order of operation, unless explicitly stated in the claims.
A structure and method for making a structure for use in building construction is provided. The structure is defined by a body having a top surface, a bottom surface, and side surfaces. A flashing liner is integrally formed with the body, and the flashing liner is defined at one or more of the side surfaces of the body. The body is capable of being attached to a building structure, and the flashing liner provides a weather interface with the building structure.
4
TECHNICAL FIELD The present disclosure relates in general to device configuration, and more particularly to a system and method for configuration of devices for wireless communication. BACKGROUND As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. With recent advances in network technology and improved affordability of networking devices, information handling system users are increasingly implementing networks (e.g., local areas networks or LANs) that utilize wireless transmissions (e.g., wireless fidelity or “WI-FI”) and wire-line transmissions in their homes and/or businesses. For example, users may implement a home or business network including an information handling system, one or more wireless-capable network devices, and a wireless access point communicatively coupled to the information handling system and network devices. Such a network may allow an information handling system (or a user thereof) to communicate with the one or more network devices via the wireless access point or vice versa. However, despite the increasing popularity of home and business networking systems, configuration complexity of such systems has prevented widespread acceptance. While network installation and setup for experienced users has been greatly simplified with setup wizards and advances in usability features included in operating systems, network configuration remains a difficult challenge for many users, particularly home consumers. These configuration challenges lead to negative customer experience and numerous technical support calls. For example, one company has reported that it receives in excess of 20,000 technical support calls per day related to digital home products, the majority attributable to wireless access point installation and setup. One difficulty with conventional approaches to configuring a number of devices is that the user must often navigate a number screens and/or dialog boxes to successfully configure a network. In addition, a user may be required to run a plurality of setup programs, which may add to the user's confusion. For example, using traditional approaches, if a user desires to wirelessly couple an information handling system, a wireless access point, and a printer, the user must often run three different setup programs—one for each of the information handling system, the wireless access point, and the printer. Also, in some traditional approaches, a user must connect the information handling system to the wireless access point via a wired connection in order to configure the devices, which may be counterintuitive for a novice user. SUMMARY In accordance with the teachings of the present disclosure, disadvantages and problems associated with configuring devices for wireless communication may be substantially reduced or eliminated. In accordance with one embodiment of the present disclosure, a method for configuring an information handling system for wireless communication with an associated wireless access point is provided. The method may include storing a wireless data file on a computer-readable medium, the wireless data file including factory default information identifying factory defaults regarding one or more wireless access points. The method may also include storing a program of instructions on the computer-readable medium. The program of instructions may be operable to, when executed (a) access factory default information from the wireless data file, and (b) configure the information handling system and the associated wireless access point for secure wireless communication between the information handling system and the associated wireless access point based on at least the accessed factory default information. In accordance with another embodiment of the present disclosure, a method for configuring devices for wireless communication is provided. The method may include detecting one or more available wireless access points. The method may also include accessing filtering information including at least one of (a) factory default information identifying one or more factory defaults for each available wireless access point and (b) a secured status of each available wireless access point. The method may also include filtering the available wireless access points based on at least the accessed filtering information. The method may further include selecting one of the filtered wireless access points as an associated wireless access point to be associated with an information handling system based on at least one of (a) a signal strength of each filtered available wireless access points and (b) a user input. In accordance with a further embodiment of the present disclosure, an information handling system may include a processor and a computer-readable medium communicatively coupled to the processor. The computer-readable medium may have stored thereon a program of instructions operable to, when executed by the processor (i) detect one or more available wireless access points; (ii) access filtering information including at least one of (a) factory default information identifying one or more factory defaults for each available wireless access point and (b) a secured status of each available wireless access point; (iii) filter the available wireless access points based on at least the accessed filtering information; and (iv) select one of the filtered wireless access points as an associated wireless access point to be associated with an information handling system based on at least one of (a) a signal strength of each filtered available wireless access points and (b) a user input. Other technical advantages will be apparent to those of ordinary skill in the art in view of the following specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: FIG. 1 illustrates a block diagram of an example wireless network system, in accordance with an embodiment of the present disclosure; FIG. 2 illustrates a flow chart of an example method for configuring an information handling system for wireless communication prior to delivering the information handling system to an end user, in accordance with an embodiment of the present disclosure; FIG. 3 illustrates a flow chart of an example method for auto-configuring devices for wireless communication, in accordance with an embodiment of the present disclosure; and FIGS. 4A-4B illustrate example user interface screens displayed during a method for auto-configuring devices for wireless communication, in accordance with the present disclosure. DETAILED DESCRIPTION Preferred embodiments and their advantages are best understood by reference to FIGS. 1-4B , wherein like numbers are used to indicate like and corresponding parts. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage resource, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. One type of information handling system is a portable computer, also known as a “laptop” and/or “notebook” computer. Portable computers often contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and efficient power consumption. For example, portable computers may have liquid crystal displays (LCDs), built-in keyboards, and may utilize a touchpad (also known as a trackpad) or a pointing stick for input, although an external keyboard or mouse may be attached. In addition, portable computers may run on a single main battery or from an external analog current/direct current (AC/DC) adapter that can charge the battery while also supplying power to the computer itself. For the purposes of this disclosure, computer-readable media may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Computer-readable media may include, without limitation, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing. For the purposes of this disclosure, the term “wire-line transmissions” may be used to refer to all types of electromagnetic communications over wires, cables, or other types of conduits. Examples of such conduits include, but are not limited to, metal wires and cables made of copper or aluminum, fiber-optic lines, and cables constructed of other metals or composite materials satisfactory for carrying electromagnetic signals. Wire-line transmissions may be conducted in accordance with teachings of the present disclosure over electrical power lines, electrical power distribution systems, building electrical wiring, conventional telephone lines, Ethernet cabling (10baseT, 100baseT, etc.), coaxial cables, T-1 lines, T-3 lines, ISDN lines, ADSL, and/or any other suitable medium. For the purposes of this disclosure, the term “wireless transmissions” may be used to refer to all types of electromagnetic communications which do not require a wire, cable, or other types of conduits. Examples of wireless transmissions which may be used include, but are not limited to, personal area networks (PAN) (e.g., BLUETOOTH), local area networks (LAN), wide area networks (WAN), narrowband personal communications services (PCS), broadband PCS, circuit switched cellular, cellular digital packet data (CDPD), radio frequencies, such as the 800 MHz, 900 MHz, 1.9 GHz and 2.4 GHz bands, infra-red and laser. Examples of wireless transmissions for use in local area networks (LAN) include, but are not limited to, radio frequencies, especially the 900 MHz and 2.4 GHz bands, for example IEEE 802.11 and BLUETOOTH, as well as infrared, and laser. Examples of wireless transmissions for use in wide area networks (WAN) include, but are not limited to, narrowband personal communications services (nPCS), personal communication services (PCS such as CDMA, TMDA, GSM) circuit switched cellular, and cellular digital packet data (CDPD), etc. FIG. 1 illustrates a block diagram of an example wireless network system 100 , in accordance with an embodiment of the present disclosure. As depicted, system 100 may include an information handling system 102 , a wireless access point 116 , and a printer 118 . Information handling system 102 may generally be operable to receive data from, and/or transmit data to printer 118 and/or another device via wireless access point 116 . In certain embodiments, information handling system 102 may be a portable computer. As shown in FIG. 1 , information handling system 102 may include a processor 103 , a memory 104 communicatively coupled to processor 103 , a user interface 106 , a storage resource 108 , and a network interface 114 . Processor 103 may comprise any system, device, or apparatus operable to interpret and/or execute program instructions and/or process data, and may include, without limitation, a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, processor 103 may interpret and/or execute program instructions and/or process data stored in memory 104 , storage resource 108 , and/or another component of information handling system 102 . Memory 104 may be communicatively coupled to processor 103 and may comprise any system, device, or apparatus operable to retain program instructions or data for a period of time (e.g., computer-readable media). Memory 104 may comprise random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), a PCMCIA card, flash memory, magnetic storage, opto-magnetic storage, or any suitable selection and/or array of volatile or non-volatile memory that retains data after power to information handling system 102 is turned off. User interface 106 may be communicatively coupled to processor 103 and may include any instrumentality or aggregation of instrumentalities by which a user may interact with information handling system 102 . For example, user interface 106 may permit a user to input data and/or instructions into information handling system 102 (e.g., via a keyboard, pointing device, and/or other suitable means), and/or otherwise manipulate information handling system 102 and its associated components. User interface 106 may also permit information handling system 102 to communicate data to a user, e.g., by means of a display device. Storage resource 108 may be communicatively coupled to processor 103 and/or memory 104 and may include any system, device, or apparatus operable to retain program instructions or data for a period of time (e.g., computer-readable media) and that retains data after power to information handling system 102 is turned off. Storage resource 108 may include one or more hard disk drives, magnetic tape libraries, optical disk drives, magneto-optical disk drives, compact disk drives, compact disk arrays, disk array controllers, and/or any computer-readable medium operable to store data. As shown in FIG. 1 , storage resource 108 may include a setup utility 110 and a wireless data file 112 . Setup utility 110 may include any suitable program of instructions executable on processor 103 and operable to configure information handling system 102 , wireless access point 116 , and/or printer 118 for wireless communication, as described in greater detail below. Wireless data file 112 may include any database, table, and/or other data structure operable to store data regarding network configuration parameters associated with wireless access point 116 , printer 118 and/or other network-capable devices (e.g., service set identifiers (SSIDs), wireless encryption protocol (WEP) keys, and/or other parameters related to network communication and network security, encryption keys, MAC addresses, serial numbers, manufacturers, model numbers, and/or other identifying information). Network interface 114 may include any suitable system, apparatus, or device operable to serve as an interface between information handling system 102 and wireless access point 116 (e.g., a wireless network interface card). Network interface 114 may enable information handling system 102 to communicate to wireless access point 116 via wireless transmissions and/or wire-line transmissions using any suitable transmission protocol and/or standard, including without limitation all transmission protocols and/or standards enumerated below with respect to the discussion of wireless access point 116 . In some embodiments, network interface 114 may provide physical access to a networking medium and/or provide a low-level addressing system (e.g., through the use of Media Access Control addresses). In certain embodiments, network interface 114 may include a buffer for storing packets received from wireless access point 116 and/or a controller configured to process packets received by wireless access point 116 . Wireless access point 116 may include any system, device or apparatus operable to communicatively couple one or more devices together to form a network. Wireless access point 116 may be a part of a storage area network (SAN), personal area network (PAN), local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a wireless local area network (WLAN), a virtual private network (VPN), an intranet, the Internet or any other appropriate architecture or system that facilitates the communication of signals, data and/or messages (generally referred to as data) via wireless transmissions. For example, wireless access point 116 may be configured to communicate with other devices via wireless transmissions, and thus may communicatively couple a plurality of wireless communication devices together to form a wireless network. In certain embodiments, wireless access point 116 may also be configured to communicate to one or more devices via wire-line transmissions, and thus may relay data among wireless devices and wired devices. Wireless access point 116 may be configured to communicate with other devices via any suitable communication protocol (e.g., TCP/IP) and/or standard (e.g., IEEE 802.11, WI-FI). Printer 118 may include any device, system or apparatus, used alone and/or in combination with one or more information handling systems to print images (e.g., text and/or pictures) on a recording medium (e.g., paper, transparencies, and/or any other suitable medium) using an imaging medium (e.g., toner, ink, and/or other suitable medium). Printer 118 may include, without limitation, a toner-based imaging device or an inkjet imaging device. FIG. 2 illustrates a flow chart of an example method 200 for configuring information handling system 102 for wireless communication prior to delivering the information handling system 102 to an end user, in accordance with an embodiment of the present disclosure. According to one embodiment, method 200 preferably begins at step 202 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 100 . As such, the preferred initialization point for method 200 and the order of the steps 202 - 210 comprising method 200 may depend on the implementation chosen. At step 202 , an order may be received for information handling system 102 . The order may also include a selection of bundled components (e.g., wireless access point 116 , printer 118 , and/or other components) to be included with the ordered information handling system 102 . The order may be received by a manufacturer and/or vendor of information handling system 102 via telephone, online, mail, or any other suitable manner. At step 204 , information handling system 102 may be manufactured according to specifications set forth in the received order. At step 206 , the vendor and/or manufacturer may store setup utility 110 on storage resource 108 of information handling system 102 . At step 208 , the vendor and/or manufacturer may configure wireless data file 112 and store wireless data file 112 in storage resource 108 of information handling system 102 . If a bundled wireless access point was ordered with information handling system 102 , wireless data file 112 may be configured with factory default identifying information regarding the bundled wireless access point (e.g., factory default SSID, factory default administrator user identification, factory default administrator password, wireless setup URL). For example, the Linksys 150N wireless access point manufactured by Cisco Systems, Inc. may have a wireless setup URL of “http://192.168.1.1/Wireless_basic.asp”, a factory default SSID of “linksys,” and a factory default administrator password of “admin.” Accordingly, if a Linksys 150N wireless access point is the bundled wireless access point ordered with information handling system 102 , wireless data file 112 may be configured with such parameters. On the other hand, if a bundled wireless access point was not ordered, wireless data file 112 may be configured with factory default identifying information for different types (e.g., brand, manufacturer, models) of wireless access points that may be supported by information handling system 102 . At step 210 , the information handling system 102 may be shipped. After completion of step 210 , method 200 may end. Although FIG. 2 discloses a particular number of steps to be taken with respect to method 200 , it is understood that method 200 may be executed with greater or lesser steps than those depicted in FIG. 2 . In addition, although FIG. 2 discloses a certain order of steps to be taken with respect to method 200 , the steps comprising method 200 may be completed in any suitable order. Method 200 may be implemented using system 100 or any other system operable to implement method 200 . In certain embodiments, method 200 may be implemented partially or fully in software and/or firmware embodied in tangible computer-readable media. FIG. 3 illustrates a flow chart of an example method 300 for auto-configuring devices (e.g., information handling system 102 , wireless access point 116 , and/or printer 118 ) for wireless communication, in accordance with an embodiment of the present disclosure. FIGS. 4A-4B illustrate example user interface screens displayed (e.g., via a display device at user interface 106 ) during method 300 , in accordance with the present disclosure. According to one embodiment, method 300 preferably begins at step 302 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 100 . As such, the preferred initialization point for method 300 and the order of the steps 302 - 316 comprising method 300 may depend on the implementation chosen. At step 302 , after receiving information handling system 102 , an end user may power on information handling system 102 for the first time (e.g., the initial end user boot of information handling system 102 ). At step 304 , processor 103 may begin execution of setup utility 110 . At step 306 , setup utility 110 may scan for available wireless access points that may be detected by information handling system 102 . At step 308 , setup utility 110 may filter the available wireless access points based on one or more parameters. In certain embodiments, filtering may be based on parameters stored in wireless data file 112 (e.g., data regarding a bundled wireless access point and/or data regarding supported wireless access points) in order to identify available wireless access points that may be unconfigured. Any such unconfigured wireless access point may be the wireless access point that is to be configured for communication with information handling system 102 . For example, because many wireless access points have factory default settings and a wireless access point to be configured with a new information handling system may have its default settings, setup utility 110 may filter based on such factory default settings (e.g., SSID) in order to find the wireless access point 116 to be configured for communication with information handling system 102 . As a specific example, if a LINKSYS 150N wireless access point is bundled with information handling system 102 , setup utility 110 may filter on the factory default SSID value of “linksys,” such that available wireless access points with an SSID other than “linksys” are filtered from the available access points. In a situation where a wireless access point is not bundled with information handling system 102 , setup utility may filter on factory default SSID values for all supported wireless access points. In the same or alternative embodiments, setup utility 110 may filter the available wireless access points based on whether such access points are unsecured or secured. Because many wireless access points are factory configured, such filtering may filter secured wireless access points (which are likely not to be newly-shipped wireless access points) from the available access points. At step 310 , setup utility 110 may identify, from the filtered available access points, the wireless access point with the highest signal strength at information handling system 102 , and select that wireless access point as the wireless access point 116 to be configured for wireless communication with information handling system 102 . In certain embodiments, setup utility 110 may prompt the end user (e.g., via user interface 106 ) to select the wireless access point 116 from a plurality of wireless access points with the highest signal strengths, such as shown in FIG. 4A for example. In other embodiments, setup utility 110 may prompt the end user to select the wireless access point 116 only if there exists an ambiguity as to which wireless access point has the highest signal strength (e.g., two or more filtered available access points have approximately equal signal strengths). At step 312 , setup utility 110 may log into the wireless access point 116 based on information (e.g., wireless access point factory default parameters) stored in wireless data file 112 . As a specific example, if wireless access point 116 is a LINKSYS 150N wireless access point, setup utility 110 may login to wireless access point using the factory default user identification (NULL) and factory default password (“admin”) stored in wireless data file 112 . At step 314 , setup utility 110 may configure wireless access point 116 and information handling system 102 for secure wireless communication. For example, setup utility may set one or more parameters associated with information handling system 102 and/or wireless access point 116 to permit secure wireless communication between information handling system 102 and wireless access point 116 . Such parameters may be assigned default values by setup utility 110 and/or may be set by the end user via user interface 106 (see FIG. 4A ). In some embodiments, setup utility 110 may enable a wireless security standard on wireless access point 116 (e.g., Wired Equivalent Privacy (WEP) or WI-FI Protected Access (WPA)) and set a passphrase, encryption key, password, and/or similar security phrase consistent with such wireless security standard. In such embodiments, setup utility 110 may also configure information handling system 102 in accordance with the wireless security standard and/or security phrase. In such embodiments, the setup utility 110 may set the security phrase based on a service tag, serial number, and/or other unique identifier associated with information handling system 102 . In the same or alternative embodiments, setup utility 110 may change the administrator user identification and/or administrator password from their factory default values (e.g., to prevent others from using such default values to access wireless access point). In these and other embodiments, setup utility 110 may change the SSID of wireless access point (e.g., to reduce the possibility of similarly-named access points in the same geographic area and/or to indicate to setup utility 110 that the wireless access point has been setup). At step 316 , setup utility 110 may display to the end user instructions for configuring printer 118 for secure wireless communication with wireless access point 118 , as shown in FIG. 4B . For example, if printer 118 is WI-FI Protected Setup (WPS)-compliant, setup utility 110 may provide instructions to the end user regarding the steps the end user may take to configure printer 118 for secure wireless communication. After completion of step 316 , method 300 may end. In the same or alternative embodiments, setup utility 110 may display to the end user instructions for configuring another wireless device, for example a WPS-compliant camera, scanner, and/or wireless headset. Although FIG. 3 discloses a particular number of steps to be taken with respect to method 300 , it is understood that method 300 may be executed with greater or lesser steps than those depicted in FIG. 3 . In addition, although FIG. 3 discloses a certain order of steps to be taken with respect to method 300 , the steps comprising method 300 may be completed in any suitable order. Method 300 may be implemented using system 100 or any other system operable to implement method 300 . In certain embodiments, method 300 may be implemented partially or fully in software embodied in tangible computer-readable media. Using the methods and systems disclosed herein, disadvantaged associated with traditional approaches to configuring devices (e.g., information handling systems, wireless access points, and printers) for wireless communication may be reduced or eliminated. For example, the methods and systems disclosed herein may allow configuration of multiple wireless devices by using only one application in a manner that may be intuitive to even the most novice user. Although the present disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and the scope of the invention as defined by the appended claims.
A system and method for configuring devices for wireless communication are disclosed. A method may include detecting one or more available wireless access points. The method may also include accessing filtering information including at least one of (a) factory default information identifying one or more factory defaults for each available wireless access point and (b) a secured status of each available wireless access point. The method may also include filtering the available wireless access points based on at least the accessed filtering information. The method may further include selecting one of the filtered wireless access points as an associated wireless access point to be associated with an information handling system based on at least one of (a) a signal strength of each filtered available wireless access points and (b) a user input.
7
BACKGROUND OF THE INVENTION [0001] The limited capacity of articular cartilage to regenerate represents a major obstacle in the management of degenerative and traumatic joint injuries. The maintenance of a functional joint surface requires that articular chondrocytes respond to extracellular signals that are generated from growth and differentiation factors, mechanical stimuli, and interactions with specific components of the extracellular matrix. The invention is directed to an extracellular matrix of type I collagen, type II collagen, type I collagen plus hyaluronate, or type II collagen plus hyaluronate, and differentiation factor-5 (GDF-5), a member of the bone morphogenetic protein (BMP) family that is involved in joint development on the chondrogenic activity of growth. [0002] Coordinated function of many cell types is regulated by integration of extracellular signal derived from soluble factors inducing growth factors and insoluble molecules such as extracellular matrix (ECM). The skeletal elements of the vertebrate limb are derived during embryonic development from mesenchymal cells, which condense and initiate a differentiation program that result in cartilage and bone. Bone morphogenetic proteins may play a crucial role in mesenchymal condensations in skeletal patterning, including the process of joint formation. This is based upon in situ hybridization and immunostaining showing that GDF-5 is predominantly found at the stage of precartilaginous mesenchymal condensation and throughout the cartilaginous cores of the developing long bone; and null mutation in GDF-5 (frameshift mutation at the mouse brachypodism locus) resulting in disruption of the formation of approximately 30% of the joints in the limb. This includes the complete absence of joint development between the proximal and medial phalanges in the forefeet and hindfeet. Further evidence of the role of GDF-5 in regulating the cellular condensation required for chondrogenesis and joint formation comes from null mutation of noggin gene which is a known antagonist of bone morphogenetic protein function. While, in mice lacking noggin, cartilage condensation initiated, the process of joint formation failed as judged by the absence of GDF-5 expression. [0003] Despite the importance of joint formation in skeletal patterning and human disease, relatively little is known about the molecular mechanisms that control where and when a joint will form. In the limb, joints typically arise by the splitting of larger skeletal precursors, rather than by collision or apposition of separate elements. This process takes place through a series of steps including: 1) initial formation of specialized regions of high density that extend in transverse stripes across developing cartilage element; 2) programmed cell death and changes in matrix production in the center of the interzone, creating a three layer structure; 3) differentiation of articular cartilage at the two edges of the interzone; and 4) accumulation of fluid-filled spaces that coalesce to make a gap between opposing skeletal elements. Expression of GDF-5 is initiated in the region of joint development 24-36 hours before the morphological appearance of the interzone. The expression continues for at least 2-3 days at a particular site, and is still evident at the three-layered interzone stage of joint development. The expression level of GDF-5 then decreases at later stages of joint formation. In vitro biological and biochemical analyses of recombinant hGDF-5 suggest that the primary physiological role of GDF-5 may be restricted to early stages of chondrogenesis of mesenchymal progenitor cells. This is based on a showing that: 1) GDF-5 stimulates mesenchymal aggregation and chondrogenesis in rat limb bud cells; 2) GDF-5 fails to stimulate alkaline phosphatase activity measured utilizing well differentiated osteoblastic cell type MC3T3-E1 cells; 3) GDF-5 stimulates alkaline phosphatase activity in rat osteoprogenitor cells ROB-C26 which is more primitive and less differentiated; 4) GDF-5 binds to distinct heterodimer of receptor for BMPs which is expressed more prevalently in less differentiated cells of mesenchymal origin. SUMMARY OF THE INVENTION [0004] This invention is directed to a method and composition for inducing or enhancing chondrogenesis in cells with an extracellular matrix containing GDF-5. The extracellular matrix consists of type I collagen, type II collagen, type I collagen plus hyaluronate or type II collagen plus hyaluronate, and contains growth and differentiation factor-5, GDF-5. An effective amount of GDF-5 to induce or enhance chondrogenesis is about 1 ng to 10 mg/ml matrix protein. A matrix is a solid porous composition having a relatively fixed three-dimensional structure. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0005] Chondrogenesis is induced by an extracellular matrix composition of type I collagen, type II collagen, type I collagen plus hyaluronate, or type II collagen plus hyaluronate containing GDF-5. Type I and II collagen represent the most abundant ECM protein in bone and cartilage, respectively. [0006] Collagen may be obtained from bone, tendons, skin, or the like. The collagen source may be any convenient animal source, mammalian or avian, including bovine, porcine, equine, or the like, or chicken, turkey or other domestic source of collagen. [0007] Hyaluronic acid is a naturally-occuring polysaccharide containing alternating N˜acetyl˜D˜glucosamine and D˜glucuronic acid monosaccharide units linked with beta 1-4 bonds and disaccharide units linked with beta 1-3 glycoside bonds. It occurs usually as the sodium salt and has a molecular weight range of about 50,000 to 8×10 6 . [0008] The collagen or collagen-hyalurate mixture is provided as a matrix, typically by lyophilization. The collagen-hyaluronate is formed by treating collagen with an active formyl aldehyde hyaluronate, formed as described in U.S. Pat. No. 5,866,165, incorporated by reference herein. The collagen hyaluronate composition is also provided as a matrix by lyophilization. [0009] The matrix is preferably implanted with an effective amount of GDF-5, which is about 1 mg to 10 mg/ml of matrix protein. [0010] To show in vitro application, fetal rat calvarial cells (FRC's) were plated on various purified extracellular matrix proteins in the presence of recombinant human GDF-5 (100 ng/ml) for 3 weeks and scored for differentiation at the level of morphology, overall proteoglycan synthesis and deposition, and aggrecan and type II collagen expression. Results show that GDF-5 stimulated chondrogenic nodule formation of FRC's plated only on type I or type II collagen. Chondrogenic nodules stained heavily with alcian blue and were positive for type II collagen and aggrecan-expression, as judged by immunohistochemical and transcriptional analyses. Cells in monolayer that surround the nodules were negative for the chondrogenic markers. In sharp contrast, GDF-5 failed to stimulate chondrogenesis in FRC's plated on fibronectin, type IV collagen or tissue culture plastic. [0011] Plastic plates were first coated with different ECM proteins including type I and II collagen, type IV collagen, or fibronectin. The results show that GDF-5 stimulated the formation of chondrogenic cell aggregate that bind heavily to the alcian blue stain. Under these conditions GDF-5 fails to stimulate the formation of characteristic nodules in FRC cultured in the presence of vehicle alone, type IV collagen, or fibronectin. Plastic culture 12 well (Costar, Cambridge, Mass.) were coated with 0.01% (w/v) of the indicated extracellular matrix proteins for 2 hours at 37 C.°. After removal of nonadsorbant protein, fetal rat calvarial cells were plated at a density of 2×10 5 cells/well in DMEM containing 10% FBS. Culture plates were then maintained for 21 days in culture media supplemented with or without GDF-5 (100 ng/ml). Plates were then stained overnight with alcian blue stain (0.5% w/v in 3% acetic acid), washed and photographed. For quantitation of alcian blue, cells were solubilized in 8M urea, and the amount of stain was quantitated using spectrophotometer (Molecular Devices, Sunnyvale, Calif.). Since alcian blue is a cationic dye which has been shown to bind to anionic proteins including proteoglycans, these results suggest that GDF-5 induces a change in cellular morphology of a subpopulation of FRC. [0012] To examine correlation of changes in cellular morphology with the process of chondrogenesis, total cellular RNA and protein were isolated from FRC culture treated with GDF-5 in the presence of type I collagen. Total cellular RNA isolated from FRC cells was subjected to a semiquantitative PCR analysis using specific primers designed to amplify aggrecan, type II collagen or type I collagen. Results show that expression of type II collagen and aggrecan mRNA is increased by around 2 and 3 respectively in cultures treated with GDF-5. Under these conditions, type I collagen mRNA expression decreased by about 20%. The expression of aggrecan and type II collagen was confirmed using slot blot analysis. [0013] Total cell lysates (100 ug) were electrophoretically separated on a 8% or 5% SDSPAGE, transferred to immobilon-P and immunoblotted using antibody specific to type II collagen or aggrecan. The results show that GDF-5 stimulated a significant increase in the steady state level of type II collagen and aggrecan. Under these conditions GDF-5 fails to stimulate expression of type II collagen or aggrecan when FRC cells are cultured in the absence of type I collagen. [0014] The collagen is also provided in matrix form for in vivo use. Type I collagen fibers were dispersed at 2% weight % ratio in distilled water and homogenized 3 times for 5 seconds each at low speed in a heavy duty blender. The pH of the slurry was then adjusted to a) pH 3.0; b) pH 7 0; or c) pH 10.0 by adding HCl or NaOH as necessary. The slurry was then cast into molds and frozen at the following temperatures prior to lyophilization: a) pH 3.0 slurry: −78° C., −40° C. or −20° C. b) pH 7.0 slurry; −40° C. c) ph 10.0 slurry; −40° C. [0018] The lyophilization cycle for the above matrices was as follows: 0° C. for 2 hours; −40° C. for 2 hours; −20° C. for 2 hours; −4° C. for 4 hours; and 25° C. for 1 hour. [0019] Hyaluronate containing active formyl aldehyde groups, prepared as disclosed in U.S. Pat. No. 5,866,165, was added to the above collagen matrices by immersion of the collagen matrix in a 2% weight % solution, pH 7-8 of the hyaluronate polyaldehyde. The immersed matrices were shaken at room temperature for 4 hours, washed 3 times and lyophilized using the lyophilization cycle described above for the collagen matrix preparation. [0020] A porous matrix fabricated from type I collagen was seeded by, 1×10 5 cell per implant (2×3×3 mm). Cells embedded in matrices were then cultured for 3 weeks in culture supplemented with or without GDF-5 (100 ng/ml). Total RNA isolated from each implant were then subjected to RT-PCR. Results indicate that GDF-5 induced expression of aggrecan and type II collagen, two well known markers of chondrogenesis. In parallel the implant material was subject to histological evaluation followed by alcian or Toludine blue staining. Results show that GDF-5 was capable of inducing marked changes in cellular morphology of FRC underscored by increase in alcian blue staining and changes in cell shape. Under these conditions FRC cells were not able to proliferate and differentiate in the ECM in the absence of GDF-5 as measured by histological evaluation total DNA, RNA or protein content. These findings suggest that the GDF-5 biological response may be significantly enhanced by type I collagen possessing 3D matrix structure. [0021] The surface property or the porosity of 3D collagen-based matrices were examined by preparing a series of implantable material possessing different porosity. Each matrix composite was either coated with or without hyaluronic acid, a major component of cartilage. The implants were then seeded with 1×10 5 cells per implant and cultured for 3 weeks in the presence of GDF-5 (100 ng/ml). Total RNA extracted from each implant were then subjected to semi-quantitative PCR analysis. Results indicate that FRC cells showed significant increase in the expression level of type II collagen and aggrecan when implanted only in matrices which were coated with hyaluronic acid and possessed the highest porosity (about 300 micron). Together these findings indicate that GDP-5 chondrogenesis activity is fully and potently synergized by a matrix which contain 1) high pore size (about 100-300 micron); and 2) is composed of type I collagen which is coated with hyaluronic acid. [0022] The molecular signaling mechanism by which GDF-5 induces chondrogenesis in the context of type I collagen was also examined using well-characterized inhibitors of intracellular signaling mediators. Results show that the ligand-dependent chondrogenesis was completely inhibited by the calcium ionophore A23187 and rapamycin not by dibutyryl-cAMP, Na 3 VO 4 , or EGTA. The known inhibitory effect of rapamycin on activation of p70S6 kinase indicate that GDF-5/type I collagen-induced chondrogenesis is mediated through p70S6 kinase activation. The known effects of A23187 on intracellular calcium concentrations suggest that the GDF-5/type I collagen-induced chondrogenesis is mediated through a sustained decrease of intracellular calcium concentration. [0023] These results indicate that cellular interaction with type I collagen significantly enhances the chondro-inductive activity of GDF-5. This effect is likely mediated by the convergence of downstream matrix and factor receptor signaling pathways. [0024] The data indicates that GDF-5 biological function is modulated by a type I collagen extracellular matrix composition and structure containing GDF-5 that this event is regulated both temporally and spatially whereby one may regulate cellular morphogenesis and joint development in vivo. [0025] The growth and differentiation factor-induced chondrogenesis is highly specific to GDF-5. It was shown that ECM-dependent chondrogenesis by GDF-5 is highly specific, by evaluating the ability of several mitogens and prototype differentiation factors under the following conditions. Chondrogenesis was assessed by monochromatic staining of FRC cultured in the presence of type I collagen and various growth factors. The results show that crude preparations of BMPs and TGFb, two other member of this class of differentiation factors, completely failed to stimulate chondrogenesis. In addition, growth factors including bFGF or IGF-I, IGF-II failed to stimulate chondrogenesis under these conditions. Together these findings suggest that the GDF-5 biological response may be distinguished from that shown by other members of TGFb superfamily. EXAMPLE [0026] In vivo activity of rhGDF-5 on collagen-based matrices. Collagen/hyaluronan matrices (CN/HA) loaded with rhGDF-5 (1, 5 and 50 μg) and implanted intramuscularly in rats for 14 days resulted in a dose-depended increase in alkaline phosphatase activity and chondrogenesis. Under these conditions, very little evidence of chondrogenesis and full terminal differentiation was detected with mineralized collagen combined with rhGDF-5. ALP activity IMPLANT (intramuscular) (n = 4 per group) (mean_SD) CN/HA 0.82 - 0.27  +1 μg rhGDF-5 3.25_0.76  +5 μg rhGDF-5 20.8_7.23 +50 μg rhGDF-5 48.9_11.3 Mineralized Collagen Matrix 0.77_0.55  +1 μg rhGDF-5 0.89_0.20  +5 μg rhGDF-5 2.68_0.30 +50 μg rhGDF-5 6.21_1.67 ALP activity = nmoles/min/mg wet wgt. implant Method [0000] In Vivo Assays, Rat Soft Tissue Implants: [0027] Matrix/growth factor combinations were implanted either subcutaneously in the thoracic region or intramuscularly in posterior tibial muscle pouches created by blunt dissection in 8 week old male Sprague-Dawley rats. At 14 days post-surgery, implants were harvested, weighed and processed for routine histology (fixed in 10% formalin, paraffin-embedded, sectioned to 6Am, and hematoxylin and eosin stained). Alternatively, implants were extracted and assayed for alkaline phosphatase activity.
A method and composition are provided for inducing or enhancing chondrogenesis in vivo or in vitro. The method is performed by exposing the cells in vitro or in vivo to an extracellular matrix comprising of type I collagen, type II collagen or a mixture of type I collagen or type II collagen and hyaluronate and further containing GDF-5.
2
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an information processing apparatus, and more particularly to an apparatus for processing information data files by using index files. [0003] 2. Related Background Art [0004] There are conventional apparatuses which manage data such as video data and audio data in the form of files. [0005] Among these apparatuses, there is an apparatus which manages a plurality of information data files by using index files storing index information for identifying the contents of each data file stored on a recording medium (e.g., refer to Japanese Patent Application Laid-Open No. 2002-278996, corresponding U.S. Publication No. 2003182279). In the apparatus described in Japanese Patent Application Laid-Open No. 2002-278996, a layout of information data files recorded on a recording medium is displayed on a display by using index files. A user designates a desired file by referring to the displayed index files and instructs to reproduce the desired file. [0006] For example, an index film may be a file (title file) storing collection of character trains each added to an information file to feature the contents thereof. [0007] The apparatus described in Japanese Patent Application Laid-Open No. 2002-278996 can manage a plurality of information data files stored on a recording medium by classifying them into common elements (virtual folders) such as record dates, travel locations and events. [0008] It is considered to make part of property information in an index file have information defining attribute information (flag) (e.g., refer to Japanese Patent Application Laid-Open No. 2003-50811, corresponding U.S. Publication No. 2004047597). In this case, it is possible to retrieve and sort files on a recording medium at high speed and to judge at high speed whether a file is to be erased. [0009] The above-described structures of prior art are, however, associated with the following problems. [0010] For example, there is a case that video data or the like recorded on a recording medium is transferred to an external apparatus such as a personal computer to edit and view it. [0011] In this case, even if video data is transferred to the external apparatus, information such as a virtual holder structure and titles cannot be confirmed on the external apparatus, because property information, title information and the like of an index file are lacking. [0012] There arises therefore a problem that a user feels difficulty in processing data transferred from the recording apparatus to the external apparatus. [0013] It can therefore be considered that data as well as the index file is transferred to the external apparatus. [0014] However, also in this case, if the external apparatus does not have a dedicated application for understanding the structure of the index file, information such as the virtual holder structure and titles cannot be confirmed on the external apparatus. [0015] There arises therefore a problem that a user feels difficulty in processing data transferred from the recording apparatus on the external apparatus. SUMMARY OF THE INVENTION [0016] It is an object of the present invention to solve the above-described problems. [0017] Another object of the present invention is to allow an external apparatus to easily process an externally received data file even if the external apparatus does not have a dedicated application for understanding the structure of an index file. [0018] In order to solve the above-described problems and achieve the above-described objects, the present invention provides a reproducing apparatus comprising: read means for reading an information data file storing information data and an index file relating to the information data file, from a recording medium; communication means for transmitting the information data file read by the read means to an external apparatus for processing the information data file in accordance with a predetermined file system; conversion means for converting the index file into a structure corresponding to the predetermined file system and generating conversion index information; and control means for controlling the communication means to transmit the conversion index information in response to a data transmission request from the external apparatus. [0019] Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a block diagram showing an example of the structure of a video camera and a personal computer PC according to an embodiment of the present invention. [0021] FIG. 2 is a diagram showing an example of directories of a file system. [0022] FIG. 3 is a diagram showing an example of a property file. [0023] FIG. 4 is a diagram showing an example of real data of a property entry. [0024] FIG. 5 is a diagram showing an example of a title file. [0025] FIG. 6 is a diagram showing a correspondence between a virtual file structure of index data and a directory structure of a file system. [0026] FIG. 7 is a diagram showing an example of information on property entries according to an embodiment. [0027] FIG. 8 is a diagram showing an example of information on title entries according to an embodiment. [0028] FIG. 9 is a diagram showing an example of a volume structure and a file structure in a disk. [0029] FIG. 10 is a diagram showing an example of virtual directory information. [0030] FIG. 11 is a flow chart illustrating a read operation of a logical block to be executed by a control microcomputer. [0031] FIG. 12 is a diagram showing an example of the structure of a file transferred to a file system of PC. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0032] Embodiments of the present invention will be described with reference to the accompanying drawings. [0033] FIG. 1 is a block diagram showing an example of the structure of a system connecting a video camera 100 and a PC 130 according to an embodiment of the present invention. [0034] First, description will be made on a photographing operation by the video camera 100 . [0035] When power is supplied by using a user interface (I/F) 113 including a power switch, a record switch and the like, a control microcomputer 112 controls each component of the video camera, and an image photographed by an image pickup unit 101 is displayed on a display 116 . [0036] In this state, upon instruction of a record start, the control microcomputer 112 controls a video encoder 103 to encode moving image data output from the image pickup unit 101 to compress its information amount. The control microcomputer 112 also controls an audio encoder 104 to encode audio data output from a microphone 102 to compress its information amount. [0037] In this embodiment, the video encoder 103 and audio encoder 104 encode moving image data and audio data in accordance with an MPEG scheme. Each output from the video encoder 103 and audio encoder 104 is called an elementary stream. [0038] MPEG elementary streams output from the video encoder 103 and audio encoder 104 are added with necessary data such as sync data and then multiplexed by a multiplexer 105 . A stream multiplexed by the multiplexer 105 is temporarily stored in a memory 107 via a memory controller 106 , as MPEG2-PS (program stream). [0039] When the memory controller 106 is requested by the control microcomputer 112 to write data on a disk media 115 , it reads MPEG2-PS data from the memory 107 . The control microcomputer 112 stores various data generated during execution of programs into the memory 107 via the memory controller 106 . [0040] The disk controller 114 writes the MPEG2-PS data read from the memory 107 onto the disk media 115 . In this embodiment, a set of MPEG2-PS data generated during a period from record start instruction to record stop instruction is recorded on the disk media 115 as one MPEG file. In this embodiment, an optical disk such as a DVD-RAM is used as the disk media. [0041] The disk controller 114 controls read/write of various data and files as to the disk media 115 and controls the format thereof. In managing files on a recording media such as the disk media 115 , generally a file system such as FAT (File Allocation Table) and UDF (Universal Disk Format) is used. [0042] For example, UDF is defined so as to establish compatibility of information data files between various computer OSes. UDF has been adopted as a file system of DVD-Video and rewritable disks such as DVD-RAM, and is expected to be adopted further by a variety of platforms. [0043] In this embodiment, UDF is used as the file system for managing files on the disk media 115 . UDF is defined on the basis of ISO/IEC 13346 (Volume and file structure of write-once and rewritable media using non-sequential recording for information interchange). [0044] Next, description will be made on a reproduction operation by the video camera 100 . [0045] Upon reproduction instruction from the user I/F 113 after the MPEG file recorded on the disk media 115 is designated, the control microcomputer 112 instructs the disk controller 114 to read the designated MPEG film from the disk media 115 . In accordance with the instruction from the control microcomputer 112 , the disk controller 114 reads the designated MPEG file from the disk media 115 , and extracts MPEG2-PS data and outputs it to the memory controller 106 . [0046] The MPEG2-PS data output from the disk media 115 is stored in the memory 107 via the memory controller 106 . In response to a request from the control microcomputer 112 , the MPEG2-PS data stored in the memory 107 is output to a demultiplexer 109 via the memory controller 106 . [0047] In order to continuously reproduce moving image data and audio data, the control microcomputer 112 controls the memory controller 106 and disk controller 114 in such a manner that the memory 107 does not overflows or underflows, by monitoring the amount of MPEG2-PS data read from the disk media 115 and stored in the memory 107 and the amount of data read from the memory 107 and supplied to the demultiplexer 109 . [0048] In this manner, the control microcomputer 112 intermittently reads data from the disk media 115 . Under the control of the control microcomputer 112 , the demultiplexer 109 demultiplexes the MPEG2-PS data into a video elementary stream and an audio elementary stream. [0049] The video elementary stream is supplied to a video decoder 110 . The video decoder 110 decodes the reproduced video elementary stream and outputs it to the display 116 and an output unit 108 . The display 116 displays the reproduced moving image data. [0050] The reproduced audio elementary stream is supplied to an audio decoder 111 . The audio decoder 111 decodes the reproduced audio elementary stream and outputs it to the output unit 108 . The output unit 108 converts the reproduced moving image data and audio data into the form suitable for outputting the data to an external TV monitor or the like, and outputs the converted data. [0051] Next, description will be made on processes to be executed after the video camera 100 and personal computer (PC) 130 of the embodiment are connected via a transmission line (interface cable) 120 . [0052] An external I/F 118 of the video camera 100 is used for connecting an external apparatus such as PC 130 to the video camera 100 . In this embodiment, although interfaces such as USB, IEEE1394, wireless LAN and the like are used, other interfaces may also be used. [0053] PC 130 processes various information data files recorded in a built-in HDD or the like, by using a file system 140 . In this embodiment, the file system uses UDF similarly to the file system of the disk media 115 . [0054] The file system 140 of PC 130 requests a particular sector of the disk media 115 from the control microcomputer 112 via the transmission line 120 and external I/F 180 . It is therefore possible to recognize the volume structure and file structure of the disk media 115 . [0055] With reference to FIGS. 2 to 8 , detailed description will be made on how the file system manages an MPEG file photographed with the video camera 100 . [0056] FIG. 2 is a diagram showing an example of the structure of the MPEG file photographed with the video camera 100 . [0057] Four MPEG files are stored under a Root directory 200 , the MPEG files including “ABCD0001.mpg” 204 , “ABCD002.mpg” 205 , 4 , “ABCD003.mpg” 206 and “ABCD004.mpg” 207 in the order of photographing. [0058] A property file 202 and a title file 203 which are index files are stored under an Index directory 201 . [0059] The property file 202 is a set of property entries indicating attributes of MPEG files. The title file 203 is a set of title entries indicating title attributes of MPEG files. [0060] FIG. 3 is a diagram showing an example of the property file 202 . [0061] Referring to FIG. 3 , the property file 202 is a table showing data lengths L_PR 1 , L_PR 2 , L_PR 3 , . . . , L_PRn and start byte positions 0 , L_PR 1 , L_PR 1 +L_PR 2 , . . . , L_PR 1 +L_PR 2 + . . . +L_PRn−1, respectively of a property entry # 1 , a property entry # 2 , a property entry # 3 , . . . , a property entry #n indicating the attributes of the MPEG files 204 to 207 . A data length is represented, for example, by a byte unit. [0062] Similarly, FIG. 5 is a diagram showing an example of the title file 203 . [0063] Referring to FIG. 5 , the title file 203 is a table showing data lengths L_TL 1 , L_TL 2 , L_TL 3 , . . . , L_TLn and start byte positions 0 , L_TL 1 , L_TL 1 +L_TL 2 , . . . , L_TL 1 +L_TL 2 + . . . +L_TLn−1, respectively of a title entry # 1 , a title entry # 2 , a title entry # 3 , . . . , a title entry #n indicating the attributes of the MPEG files. A data length is represented, for example, by the byte. [0064] FIG. 4 is a diagram showing an example of the structure of actual data of a property entry. [0065] Referring to FIG. 4 , real data of a property entry is constituted of a type, a property length, a property entry number, a title entry number, a parent entry number and a file identifier. [0066] The type indicates whether the property entry is an upper most level folder, i.e., a root holder, another holder, or a file corresponding to video data (MPEG file). The type is one byte data having the start byte address at a 0-th byte position. [0067] The property data length shows the data length of the property entry in bytes. The property data length is one byte data having the start byte address at a 1-st byte position. [0068] The property entry number starts from # 1 and is a unique number assigned to each property entry, i.e., an identifier for identifying each property entry. The property entry number is two-byte data having the start byte address at a 2-nd byte position. [0069] The title entry number indicates a title entry ( FIG. 5 ) corresponding to title information of the property entry. The title entry number is two-byte data having the start byte address at a 4-th byte position. [0070] The parent entry number is a property entry number of a folder to which the property entry belongs. The parent entry number is two-byte data having the start byte address at a 6-th byte position. The parent entry number of the root holder is # 0 . [0071] The file identifier indicates an MPEG file name if the type of the property entry is a file, and is variable length data having the start byte address at an 8-th byte position. Real data of the title entry contains character trains, character codes and the like. [0072] Next, description will be made on a specific example of a virtual holder structure of the property file 202 and title file 203 which are index files. [0073] It is assumed that the disk media 115 records the four MPEG files managed on the file system as shown in FIG. 2 . [0074] It is also assumed that the MPEG files are classified by the virtual folder structure and title names 301 to 309 shown in FIG. 6 . Reference numerals 301 , 302 , 304 , 305 and 308 represent virtual folders, and reference numerals 303 , 306 , 307 and 309 represent virtual files. [0075] Namely, the ABCD0001.mpg file 204 corresponds to a file 309 having a title name “bus stop”, and is stored in a folder 308 having a title name “town” under a folder 304 having a title name “travel”. [0076] The ABCD0002.mpg file 205 corresponds to a file 307 having a title name “surfing”, and is stored in a folder 305 having a title name “island” under the folder 304 having the title name “travel”. [0077] The ABCD0003.mpg file 206 corresponds to a file 306 having a title name “sandy beach”, and is stored in the folder 305 having the title name “island” under the folder 304 having the title name “travel”. [0078] The ABCD0004.mpg file 207 corresponds to a file 303 having a title name “field day”, and is stored in a folder 302 having a title name “child”. [0079] FIG. 7 is a diagram showing property entries of the property file 202 when the MPEG files are classified by the virtual folder structure and title names shown in FIG. 6 . [0080] FIG. 8 is a diagram showing title entries of the title file 203 when the MPEG files are classified by the virtual folder structure and title names shown in FIG. 6 . [0081] In FIG. 7 , the property entry number # 1 is a root holder having no title entry, a parent entry 0 , and no file identifier. The property entry number # 2 is a folder having the title name “child”, a title entry number # 1 as seen from FIG. 8 , a parent entry number # 1 because it belongs to the root holder, and no file identifier. [0082] The property entry number # 3 is a file having the title name “field day”, a title entry number # 2 as seen from FIG. 8 , a parent entry number # 2 because it belongs to the “child” folder, and a file identifier “ABCD0004.mpg”. The property entry number # 4 is a folder having the title name “travel”, a title entry number # 3 as seen from FIG. 8 , the parent entry number # 1 because it belongs to the root folder, and no file identifier. [0083] The property entry number # 5 is a folder having the title name “island”, a title entry number # 4 as seen from FIG. 8 , a parent entry number # 4 because it belongs to the “travel” folder, and no file identifier. [0084] The property entry number # 6 is a file having the title name “sandy beach”, a title entry number # 5 as seen from FIG. 8 , a parent entry number # 5 because it belongs to the “island” folder, and a file identifier “ABCD0003.mpg”. The property entry number # 7 is a file having the title name “surfing”, a title entry number # 6 as seen from FIG. 8 , the parent entry number # 5 because it belongs to the “island” folder, and a file identifier “ABCD0002.mpg”. [0085] The property entry number # 8 is a folder having the title name “town”, a title entry number # 7 as seen from FIG. 8 , the parent entry number # 4 because it belongs to the “travel” folder, and no file identifier. The property entry number # 9 is a file having the title name “bus stop”, a title entry number # 8 as seen from FIG. 8 , a parent entry number # 8 because it belongs to the “town” folder, and a file identifier “ABCD0001.mpg”. [0086] The control microcomputer 112 analyzes these index files, i.e., the property film 202 and title file 203 , and displays the virtual folder structure and title names 301 to 309 on the display 116 . [0087] FIG. 9 is a diagram showing an example of a volume structure and a file structure of UDF configured on the disk media 115 . [0088] In order to handle the disk media 115 as a logical volume, the storage area of the disk media 115 is divided into units called sectors, and logical sector numbers (hereinafter called LSN) from # 0 to the last LSN are assigned to sectors. A length of a logical sector is 2048 bytes equal to a length of a physical sector of the disk media 115 . A logical sector number # 0 is assigned to a sector having a physical sector number 031000h where h denotes a hexadecimal number. [0089] A physical sector number (hereinafter called PSN) is the sector number assigned to each sector of the disk media 115 , and is recorded in a header field of each sector data. By using this sector number, data is read from the disk media. [0090] Referring to FIG. 9 , a start volume descriptor pointer is recorded at the same LSN of all DVD disks. In order to improve reliability, the start volume descriptor pointer is recorded at two positions, LSN=256 and the last LSN. The start volume descriptor pointer records head LSNs and the number of data bytes of each of a main volume descriptor train and a reserved volume descriptor train. In order to improve reliability, the same data is recorded in both the main volume descriptor train and reserved volume descriptor train. [0091] A partition descriptor and a logical volume descriptor are recorded in the main volume descriptor train or reserved volume descriptor train. A head LSN of the partition start sector is recorded in the partition descriptor. A start logical block number (LBN) and the number of data bytes of a file set descriptor train are recorded in the logical volume descriptor train. LBN is a serial number starting from # 0 at the partition head position. A sector position in each partition is represented by LBN. Therefore, the relation between LSN and LBN is expressed by: LSN =partition head LSN+LBN. [0092] By using this relation, the disk controller 114 converts LBN into LSN, and LSN into PSN to thereby determine the physical sector position of the disk media 115 to be accessed. Data is read from the determined position. [0093] In FIG. 9 , a spatial bit map descriptor is recorded at LBN=0 to 79. The spatial bit map descriptor has a spatial bit map indicating whether each logical block can be allocated. Each bit of the spatial bit map corresponds to each logical block. If the bit value is “1”, the logical block is still not allocated, whereas if the bit value is “0”, the logical block is already allocated. [0094] A file set descriptor is recorded at LBN=80. The file set descriptor records block position information of a file entry of a root directory. A terminator descriptor is recorded at LBN=81. The file entry of the root directory is recorded at LBN=82. The file entry is used in order to store various attribute information unique to each file and information on a time stamp, a file record position (LBN) and a file size. [0095] In FIG. 9 , a file entry of the ABCD0001.mpg file is recorded at LBN=100, and its actual data is recorded at LBN=101 to 150. A file entry of the ABCD0002.mpg file is recorded at LBN=151, and its actual data is recorded at LBN=152 to 300. A file entry of the ABCD0003.mpg file is recorded at LBN=301, and its actual data is recorded at LBN=302 to 600. A file entry of the ABCD0004.mpg file is recorded at LBN=601, and its actual data is recorded at LBN=602 to 900. [0096] LBN 901 to the last LBN are still not allocated and recorded, and data is not recorded. Therefore, the corresponding bit value of the spatial bit map descriptor is “1” indicating an unallocated state. [0097] As described above, the UDF file system can know all the directory structures and file structures of the disk media 115 along a route starting from the file entry of each root directory. [0098] In the embodiment, as PC 130 is connected to the video camera 100 , prior to a data read request from the file system 140 of PC 130 , the control microcomputer 112 controls the memory controller 106 to form a virtual logical block space on the memory 107 and store virtual directory information representative of the directory structures of the disk media 115 . [0099] Similar to the logical block space of the disk media 115 , the virtual logical block space has one block capacity of 2048 bytes and a virtual LBN (hereinafter called VLBN) is assigned to each block. [0100] The same LBN (VLBN=82) as that of the logical block of the disk media 115 is assigned to the file entry of the root directory. By referring to the property entries ( FIG. 7 ) and title entries ( FIG. 8 ) of the index files, the control microcomputer 112 generates virtual directory information for management by replacing the virtual folder structure and title names based on the index files shown in FIG. 6 with the file structure and file names of UDF. FIG. 10 is a diagram showing the virtual directory information generated in this way. [0101] VLBN of logical blocks excepting the file entry of the root directory is assigned LBN (LBN=901 to the last LBN) in the unallocated state in the spatial bit map on the disk 115 . [0102] VLBN=901 is a block of the root directory and is constituted of a plurality of file identifier descriptors. Main information contained in the file identifier descriptor is the file name and position information of the file entry. In this embodiment, the title name of a corresponding property entry is used as the file name, and the position information of the file entry is designated by VLBN. However, if the file identifier descriptor corresponds not to the directory but to the file, the file name is the title name of the corresponding property entry, added with a file identifier extension of the property entry. The position information of the file entry designates LBN of the file entry of the disk media 115 . [0103] It can be seen from FIG. 7 that the property entries having the root folder as a parent entry are # 2 and # 4 which are both not the file but the folder and that the corresponding title entry numbers are # 1 and # 3 . It can be seen from FIG. 8 that there are a folder having the title name “child” and a folder having the title name “travel”, under the root folder. Therefore, the block of the root directory at VLBN=901 records: a file identifier descriptor (file entry VLBN=82) of the parent directory (in this embodiment, root directory) of the root directory; a file identifier descriptor (file entry VLBN=902) of the directory name “child”; and a file identifier descriptor (file entry VLBN=904) of the directory name “travel”. The directory name is the virtual folder name (the title name of the virtual holder). [0104] VLBN=902 corresponds to the block of the file entry of the “child” directory, and this block records the block position (VLBN=903) of the “child” directory. It can be seen from FIGS. 7 and 8 that the property entry number # 3 corresponds to a file under the “child” directory corresponding to the property entry number # 2 . Its entity is the file having the file name “ABCD004.mpg” and the title name “field day”. VLBN=903 corresponds to the block of the “child” directory, and this block records the file identifier descriptor (file entry VLBN=82) of the parent directory (root directory) of the “child” directory, and the file identifier descriptor (file entry VLBN=601) having a file name “field day.mpg” obtained by adding an entity file extension “.mpg” to the title name “field day”. [0105] Since the file entry of the entity file ABCD0004.mpg” is allocated to LBN=601 of the disk media 115 (refer to FIG. 9 ), the file entry of the “field day.mpg” is VLBN=601. [0106] VLBN=904 corresponds to the block of the file entry of the “travel” directory, and this block records the block position (VLBN=905) of the “travel” directory. [0107] VLBN=905 corresponds to the block of the “travel” directory, and as seen from FIGS. 7 and 8 this block records the file identifier descriptor (file entry VLBN=82) of the parent directory (root directory) of the “travel” directory, the file identifier descriptor (file entry VLBN=906) of the “island” directory and the file identifier descriptor (file entry VLBN=908) of the “town” directory. [0108] VLBN=906 corresponds to the block of the file entry of the “island” directory, and this block records the block position (VLBN=907) of the “island” directory. [0109] VLBN=907 corresponds to the block of the “island” directory, and as seen from FIGS. 7 and 8 this block records the file identifier descriptor (file entry VLBN=904) of the parent directory (“travel” directory) of the “island” directory, the file identifier descriptor (file entry VLBN=301) of the “sandy beach” file and the file identifier descriptor (file entry VLBN=151) of a “surfing.mpg” file. [0110] VLBN=908 corresponds to the block of the file entry of the “town” directory, and this block records the block position (VLBN=909) of the “town” directory. [0111] VLBN=909 corresponds to the block of the “town” directory, and as seen from FIGS. 7 and 8 this block records the file identifier descriptor (file entry VLBN=904) of the parent directory (“travel” directory) of the “town” directory and the file identifier descriptor (file entry VLBN=100) of a “bus stop.mpg” file. [0112] Next, with reference to the flow chart shown in FIG. 11 , description will be made on the operation of the control microcomputer 112 to be executed upon a read request of data in the disk media 115 from the file system 140 of PC 130 after the virtual directory information is generated in the manner described above. [0113] When a read request of data recorded in a logical block of LBN=X (X=0−the last LBN: X is an integer) of the disk media 115 is received from the file system 140 via the external I/F 118 (Step S 1101 ), the control microcomputer 112 judges whether the virtual disk information in the memory 107 contains the virtual logical block at VLBN=X (Step S 1102 ). If the block at VLBN=X is contained, the flow advances to Step S 1103 whereat data of the virtual logical block at VLBN=X is read from the memory 107 and then the flow advances to Step S 1105 . If the virtual logical block at VLBN=X is not contained, the disk controller 114 is instructed to read data of the logical block at LBN=X of the disk media 115 and then flow advances to Step S 1105 (Step S 1104 ). [0114] At Step S 1105 , data read at Step S 1103 or S 1104 is transmitted (transferred) to the file system 140 of PC 130 . Thereafter, the flow returns to Step S 1101 to wait for a read request from the file system 140 . [0115] For example, upon reception of a read request of LBN=82 from the file system 140 , the control microcomputer 112 sends the data at VLBN=82, i.e., the data of the file entry of the root directory, to the file system 140 . The file system 140 can know from this data that the logical block number (actually, the virtual logical block number) at which the file entry of the root directory is stored, is 901. The file system 140 requests transmission of the data at LBN=901. [0116] By repeating these operations, the virtual directory information shown in FIG. 10 is transmitted in response to the transmission request from the file system of PC 130 . [0117] Therefore, when the MPEG files 204 to 207 of the disk media 115 having the virtual folder structure and title names shown in FIG. 6 are to be transferred to PC 130 , the virtual folder structure and title names shown in FIG. 6 are replaced with the file structure and file names in conformity with UDF as shown in FIG. 12 . [0118] Therefore, even if there is no dedicated application for recognizing the virtual directory structure shown in FIG. 6 , the file structure and file names similar to the virtual folder structure and title names shown in FIG. 6 can be displayed on PC 130 . [0119] The file name has the title name added with an extension (.mpg) of video data. Namely, the file name is changed to a name obtained by adding the extension of MPEG data to the title name of each MPEG file, and this changed name is transmitted to the file system 140 . [0120] As described above, according to the embodiment, upon reception of a transmission request of data in the disk media from PC 130 , virtual directory information on the directory structure, directory names and file names corresponding to the virtual folder structure, virtual folder names and file names on the disk media 115 , is generated. Upon reception of a read request of data on the disk media 115 from PC 130 , the virtual directory information is read and transmitted to PC 130 . [0121] The virtual directory information contains the data of a block in which the file entry of the root directory of the disk media 115 , and the numbers of blocks in an unallocated state in the disk media 115 are assigned as the virtual logical block numbers, excepting the block in which the file entry of the root directory is recorded. [0122] All directories and file entries under the root directory are described in the virtual directory information. The file entries of information data files and actual MPEG file data are not described in the virtual directory information. The file identifier descriptor representative of a MPEG file indicates the head logical block number at which the file entry of the MPEG file in the disk media 115 is recorded. [0123] In this embodiment, although MPEG files are processed by the video camera 100 and PC 130 , the present invention is also applicable to other files such as still image files containing JPEG encoded still image data and audio files containing audio data. [0124] As described above, according to the embodiment, when information data files recorded on a recording medium is to be transmitted to an external apparatus, index file information such as the virtual folder structure and title names is replaced with the structure in conformity with the file system of the external apparatus. [0125] Therefore, even if the external apparatus does not have a dedicated application for understanding the structure of index files, the external apparatus can display the file structure and file names similar to the virtual folder structure and title names. It is therefore easy for users to handle information data files recorded on a disk media. [0126] The embodiment can be realized by making the control microcomputer (computer) 112 execute a program for the processes shown in FIG. 11 . Embodiments of the present invention may be applied to means for supplying a computer with the program, e.g., a computer readable storage media such as a CD-ROM storing the program, and a transmission media for transmitting the program such as the Internet. Embodiments of the present invention may also be applied to computer program products storing the program such as a computer readable recording medium. The above-described program, recording medium, transmission media and computer program products are considered to fall within the scope of the present invention. The recording medium may be a flexible disk, a hard disk, an optical disk, a magneto optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM or the like. [0127] The above-described embodiments are only illustrative for embodying the present invention and are not construed to limitatively analyze the technical scope of the present invention. Namely, the present invention can be reduced in practice in various forms without departing from the technical concept or main features of the present invention. [0128] This application claims priority from Japanese Patent Application No. 2004-319524 filed on Nov. 2, 2004, which is hereby incorporated by reference herein.
A reproducing apparatus comprises: a read unit for reading an information data file storing information data and an index file relating to the information data file, from a recording medium; a communication unit for transmitting the data file read by the read unit to an external apparatus for processing the data file in accordance with a predetermined file system; a conversion unit for converting the index file into a structure corresponding to the predetermined file system and generating conversion index information; and a control unit for controlling the communication unit to transmit the conversion index information in response to a data transmission request from the external apparatus.
6
CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 10/502,995, receiving a filing date of 18 May 2005, and which claims priority to International Patent Application PCT/EP02/11675. The co-pending parent application is hereby incorporated by reference herein in its entirety and is made a part hereof, including but not limited to those portions which specifically appear hereinafter. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to a construction machine, in particular for working ground surfaces or for stripping traveled surfaces by a milling roller which has a multitude of chisels. [0004] 2. Discussion of Related Art [0005] Construction machines are known, for example, as road milling machines. They have a milling roller equipped with a multitude of chisels, in particular round-shaft chisels. The milling roller rotates during operation and the chisels engage with the ground covering to be worked. The chisels are subjected to continuous wear and must be replaced after a defined time of operation. However, the service life of the chisels largely depends on the milling conditions. Often, the machine operator exchanges the chisels either too early or too late. If they are replaced too early, unnecessary tool expenses arise. If replaced too late, damage to the milling roller can occur. [0006] A further problem in the milling process relates to premature chisel drop-out. One or several chisels can break because of external effects, or because of tool irregularities. Then, no material is removed at the places where the chisel is positioned. In addition, the stress on the adjoining tools increases and the tools are subjected to greater stresses. [0007] Stabilizers, recyclers and trimmers are also known construction machines. SUMMARY OF THE INVENTION [0008] It is one object of this invention to provide a construction machine of the type mentioned above, by which an optimized working operation can be performed. [0009] This object is achieved with a signal pickup unit that is assigned to a machine component, or another machine component which is directly or indirectly involved in the work process. The signal pickup unit detects an operational status of the machine component, and the signal pickup unit is connected to a signal output unit via a signal processing arrangement. [0010] One or if required, several machine component can be monitored by the signal pickup unit. In the process, the operational status of the machine component is used as a parameter, or characteristic diagram. The detected parameters can be compared with a reference quantity or a reference quantity diagram. As soon as an inadmissible deviation occurs, a machine operator can perform the required corrective actions. The reference quantity, or the reference quantity diagram, can be a constant, which is stored in the evaluating unit, or is selected from a multitude of constants in a data bank of the evaluating unit on the basis of limiting conditions. [0011] In an advantageous manner, the reference quantity and/or the reference quantity diagram can also be chronologically variable. For forming the reference values, the reference quantity and/or the reference quantity diagram can be determined empirically in a machine status wherein the tools are not worn out. [0012] It is also possible that the reference quantity and/or the reference quantity diagram is recursively defined, such as is derived from the parameters and/or the characteristic diagram of the historical operational status. [0013] The operational status of the monitored machine component can be determined either continuously or at predetermined measuring intervals. [0014] For a better explanation, reference is made in what follows to a road milling machine. However, the explanations analogously apply to construction machinery of any type. [0015] The evaluation of the measured result preferably occurs so that the signal picked up by the signal pickup unit is conducted to an evaluating unit. The evaluating unit compares the picked-up signal with a preset value and forms a difference signal from the picked-up signal and the preset value. It is thus possible to provide an error report which is automated to the greatest extent. Ideally, the preset value can be empirically determined by a detection circuit, and the preset value can be read into the evaluation circuit by the detection circuit. During this, the machine operator can determine the preset values during the milling process, for example with chisels which are not worn out. [0016] In one embodiment of this invention, a machine chassis is supported by a running gear, wherein one or several drive motors are assigned to the running gear, and the signal pickup unit detects the power consumption of the drive motor. Use is made of the knowledge that changed wear conditions of the milling roller also lead to a change of the output parameters of the drive motor. [0017] For example, an increased drive effort can be required because of increased wear of the chisel. With this embodiment of this invention, the drive motors are designed as electric motors, and the signal pickup unit detects the supplied electrical current or the drive motors are designed as hydraulic motors. The signal pickup unit detects the hydraulic pressure in the fluid circuit assigned to the drive motor. [0018] In one embodiment of this invention, the machine chassis is supported, at least in some areas, by at least one adjustment device, and the machine chassis can be height-adjusted, at least in some areas, by the adjustment device. A fluid under pressure is assigned to the adjustment device, and the signal pickup unit detects the pressure in the fluid. [0019] The forces occurring during milling are indirectly detected with this arrangement. The cutting forces are low for unworn cutting chisels which are ready to cut. The vertical portion of the cutting forces is directed opposite the force of gravity and therefore relieves the burden on the adjustment device, which otherwise would have to support the entire weight of the machine. The pressure in the fluid assigned to the adjustment device decreases proportionally with the vertical portion of the cutting forces. This value can also be determined by a force measurement, for example with a wire strain gauge, on at least one of the adjustment devices or another structural component. [0020] It is also possible for the signal pickup unit to detect the forward progress of the machine which can then be compared with the actual output parameters of the road milling machine, in particular with the drive output required for the milling roller. [0021] If, for example, at constant drive output the forward progress of the machine slows, then it is possible to draw conclusions regarding an increased wear status. [0022] A combined calculation of the following values can also be performed: vertical force direction detected by the adjustment device, for example, and horizontal force direction detected by the drive data, for example. A vector can be formed by a linear combination and the length or directional change can be used as evaluation criteria. [0023] In accordance with one embodiment of invention, the signal pickup unit detects the vibration of the machine component. This arrangement is based on different wear conditions that also have an effect on the vibration behavior of individual machine components. This design of a machine is based on the knowledge that a uniform vibration can be detected in view of the uniform rotatory movement of the milling roller. In the unworn state, this vibration has fixed parameters, including amplitude and period. As a result of a tool break, for example, the vibration undergoes a sudden change toward an irregular vibration, compared with the vibration prior to the break. [0024] With uniformly proceeding wear, the amplitude of the parameters slowly changes in amount. Thus the irregularity or regularity of the signal is of lesser importance, or does not exist. [0025] Thus it is preferably possible to detect the vibration by a displacement transducer, or a speed or an acceleration sensor. [0026] Further invention embodiments can also be distinguished if the signal pick-up unit detects the drive moment at one or several places of a drive mechanism driving the milling roller, or if the signal pickup unit determines the motor parameters. [0027] In one embodiment of this invention the signal pickup unit has a pulse generator assigned to the milling roller. A position determination of the milling roller can be performed by the pulse generator. If the signal detected by the signal pickup unit is processed together with the information from the pulse generator, it is possible to draw detailed conclusions regarding the position of a break-down point, for example a broken shaft. [0028] One object of this invention is also achieved with a recognition unit that optically detects at least a portion of the milling pattern generated by the milling roller. [0029] The quality of the milling pattern can be checked by the optical recognition unit, for example a camera. Errors due to the wear of the chisels or of a chisel break can be detected in the milling pattern. It is also possible to use a signal pickup unit designed in the manner described above in addition to the optical recognition unit. During this a further detailed error detection can take place. [0030] In accordance with this invention, the recognition unit can have at least one position sensor which detects the milling depth. BRIEF DESCRIPTION OF THE DRAWINGS [0031] This invention is explained in greater detail in view of an exemplary embodiment represented in the drawings, wherein: [0032] FIG. 1 is a lateral view of a construction machine, such as a road milling machine; [0033] FIG. 2 is a schematic view of a milling roller, in a front view; [0034] FIGS. 2 a and 2 b show the surface profile milled by the milling roller in accordance with FIG. 2 , in a schematic representation; [0035] FIG. 3 shows a milling roller in accordance with FIG. 2 , but with a defective place; [0036] FIGS. 3 a and 3 b show the surface profile milled by the milling roller in accordance with FIG. 3 in a schematic representation; [0037] FIG. 4 shows the milling roller in accordance with FIG. 2 , in a lateral view; [0038] FIG. 4 a shows a vibration image taken at a road milling machine equipped with a milling roller in accordance with FIG. 4 ; [0039] FIG. 5 shows the milling roller in accordance with FIG. 3 , in a lateral view; and [0040] FIG. 5 a shows a vibration image taken at a road milling machine equipped with a milling roller, in accordance with FIG. 5 . DESCRIPTION OF PREFERRED EMBODIMENTS [0041] The lateral view of a road milling machine shows the basic structure and the components of the machine. A machine frame 10 is the basis for the machine, and is supported by two front running gears 11 and two rear running gears 12 . In this case, the running gears 10 and 11 can be driven by electric motors or hydraulic motors. These drive mechanisms operate synchronously. It is thus sufficient to assign sensors S 6 and S 7 for detecting the electrical current or the pressure and the speed to only one running gear, for example 11 . [0042] A milling box 13 is attached to the machine frame 10 between the front and rear running gears 11 and 12 . The milling box 13 contains at least one milling roller with chisel holders and chisels. The milling roller is driven by a drive unit 16 , which has a Diesel engine, wherein a sensor S 8 detects the transferred torque, and a sensor S 10 detects other operating data, such as motor rpm, exhaust gas temperature, boost pressure, and the like. [0043] A camera K is attached to the machine frame 10 between the milling box 13 and the rear running gear 12 , by which the milling image is detected and recorded. The image is transferred to a video terminal BS in the cab 14 of the machine and is displayed. The driver seated on the driver's seat 15 can see the milling image on the video terminal BS arranged in the area of the dashboard 18 and can check its status and draw a conclusion regarding its quality. A continuous check can be performed if the camera K and the video terminal BS are switched on during the entire operating time of the machine. However, checking can be adjusted so that the devices and a display are switched on only when a request is initiated. [0044] Sensors S 2 and S 4 , which detect the position of the milling roller, the milling pressure and the milling torque, are attached to the milling box 13 . A sensor S 5 attached to the machine frame 10 above the milling box 13 detects the vibrations of the milling box 13 in the direction of travel, transversely to the direction of travel of the machine, and perpendicularly with respect to the pavement. [0045] The machine frame 10 can be adjusted with respect to the running gears 11 and 12 via a height adjustment device in order to change the penetration depth of the milling roller in the pavement. The penetration depth is detected by the sensor S 1 . The pressure of the height adjustment device can be detected by the sensor S 9 . [0046] The removed milling material is moved away from the milling box 13 by a conveyor device, wherein the conveyor device has an endless conveyor belt 17 , one end of which is hinged to the machine frame 10 and which can, as shown by the sensors S 11 and S 12 , be adjusted in height and laterally pivoted in order to assure a transfer to a vehicle arranged underneath, without damage to the vehicle and/or the endless conveyor belt 17 . [0047] The measured signals detected by the sensors S 1 to S 12 are also transmitted to the cab 14 and displayed in the area of the dashboard 18 . In this case, individual display elements can be assigned to all sensors, which can be activated permanently or upon request. However, a central display device can be assigned to all sensors, on which the requested measured signal is displayed, wherein the display also contains the preset permissible range of the measured signals. [0048] The measured signals can be continuously detected independently of the display, and compared with the preset value ranges. If the measured signals lie below or above the preset value ranges, a warning signal can be automatically triggered, and the error situation can be shown at the central display device. [0049] Extensive wear of the chisels and other irregularities during operation result in large changes in the monitored operating data and are monitored, displayed and recognized by the driver of the road milling machine, which then can initiate steps for error location and error removal. This makes the operation by the road milling machine considerably easier and assures that components of the machine are not overloaded, damaged or even destroyed. [0050] For explaining the optical milling image monitoring, a milling roller 30 is first shown in the unworn state ( FIG. 2 ) in FIGS. 2 to 3 b . As this representation shows, all chisel holders 31 are equipped with round-shaft chisels 32 . The milling image A shown in FIGS. 2 a and 2 b results from such a milling roller 30 . [0051] If a chisel is lost from the milling roller 30 , for example because of a tool break, the milling image B represented in FIGS. 3 a and 3 b results. It can be seen, in particular in the enlarged detailed view in accordance with FIG. 3 b that at the place which was not worked because of the loss of the chisel raised material P remains in the pavement. This can be visually detected by a camera. [0052] The milling rollers 30 of FIGS. 2 and 3 are shown, in a lateral view, in FIGS. 4 and 5 . FIGS. 4 a and Sa represent the vibration image recorded by an appropriate sensor.
A road milling machine having a milling roller with a plurality of chisels. A signal receiving unit is assigned to a machine component which is directly or indirectly involved in the milling process or to another machine component. The signal receiving unit detects an operating condition of the machine component and is connected to a signal emitting unit. An optical detecting device may be assigned to the road milling machine, whereby operations are made easier and the milling pattern is optimized.
4
BACKGROUND OF THE INVENTION Field of the Invention This invention is a recombinant battery wherein oxygen formed electrolytically at the positive plates inside the battery is able to migrate to the negative plates for electrolytic recombination, a plate separator for such a battery, and a method for producing such a battery. Briefly, the plate separator is made from fibers having different capabilities for holding electrolyte; the fibers are used in such proportions that the separator, even in the presence of excess electrolyte, is capable of holding only the amount of electrolyte desired in the battery. The fibers having different capabilities for holding electrolyte can be, for example, coarse glass fibers and fine glass fibers or a mixture of glass fibers and polypropylene fibers. Definitions Subsequently herein, the term "percent v/v" means percent by volume; the term "percent w/w" means percent by weight; all temperatures are in °C.; and the following abbreviations have the meanings indicated: μm means micrometer or micrometers (numerically equal to micron or microns); mg=milligram or milligrams; g=gram or grams; kg=kilogram or kilograms; l=liter or liters; ml=milliliter or milliliters; and cm=centimeter or centimeters. The Prior Art Recombinant batteries have been known for a number of years, being disclosed, for example, in U.S. Pat. No. 3,362,861, McClelland et al. This patent also discloses such batteries having vent valves through which gases which form in service can escape to prevent the build-up of an excessive internal pressure. U.S. Pat. No. 3,159,508, Chreitzberg, discloses a battery including a container designed to prevent an undue build-up of hydrogen pressure. According to the patent, the container is made from a material which exhibits substantially increased permeability to hydrogen without a corresponding increase in permeability to oxygen. Recombinant battery plate separators made from glass fibers of a plurality of diameters and made from mixtures of glass fibers and polypropylene fibers are also known. For example, U.S. Pat. No. 4,465,748, Harris, discloses glass fiber sheet material for use as a separator in an electrochemical cell, e.g., in such a battery, and made from 5 to 35 percent by weight of glass fibers less than 1 μm in diameter; the patent also discloses a glass fiber sheet for such use wherein there are fibers of a continuous range of fiber diameters and lengths, and most of the fibers are not over 5 mm in length. U.S. Pat. No. 4,216,280, Kono et al., discloses glass fiber sheet material for use as a plate separator in such a battery, and made from 50 to 95 percent by weight of glass fibers less than 1 μm in diameter and 50 to 5 percent by weight of coarser glass fibers. The coarser glass fibers, the reference says, have a fiber diameter larger than 5 μ m, preferably larger than 10 μm, and it is advantageous for some of the coarser fibers to have diameters of 10 μm to 30 μm. U.S. Pat. No. 4,373,015, Peters et al., discloses sheet material for use as a separator in such a battery, and "comprising organic polymeric fibers"; both of the examples of the reference describe the sheet material as "short staple fiber polyester matting about 0.3 mm thick", and indicate that the polyester fibers range from about 1 μm to about 6 μm in diameter. Finally, sheet separators for use in conventional (non-recombinant) batteries and comprising both glass fibers and organic fibers are disclosed in all of the following U.S. Pat. Nos. 4,529,677, Bodendorf; 4,363,856, Waterhouse; and 4,359,511, Strzempko. U.S. Pat. No. 4,367,271, Hasegawa, discloses storage battery separators composed of acrylic fibrils in an amount of up to about 10 percent by weight, balance glass fibers. Japanese patent document No. 55/146872 discloses a separator material comprising glass fibers (50-85 percent by weight) and organic fibers (50-15 percent by weight). U.S. Pat. No. 4,245,013, Clegg et al., discloses a separator made by overlaying a first sheet of fibrous material including polyethylene fibers with a second sheet of fibrous material including polyethylene and having a synthetic pulp content higher than the first sheet. So far as is known, there has not heretofore been a suggestion of a plate separator which, when saturated with electrolyte, leaves a residuum of unfilled voids through which a gas can transfer from one plate to another because the separator is not capable of holding an amount of electrolyte which is sufficient to fill all the voids. SUMMARY OF THE INVENTION Briefly, the instant invention is a fibrous sheet useful as a battery plate separator. The sheet consists essentially of first and second fibers, both of which are inert to a particular aqueous electrolyte. The first fibers impart to the sheet a given absorbency greater than 90 percent relative to the particular electrolyte, when surfactant-free, while the second fibers impart to the sheet a different absorbency less than 80 percent relative to the electrolyte, when surfactant-free. The first and second fibers are present in the sheet in such proportions that the sheet has an absorbency with respect to that electrolyte, when surfactant-free, of from 75 to 95 percent. Preferably the first fibers are glass fibers, most desirably glass fibers having an average diameter less than 5 μm. In one preferred embodiment the second fibers are organic fibers that are hydrophobic relative to the electrolyte, when surfactant-free, most desirably polyethylene or polypropylene fibers. In another preferred embodiment the second fibers are coarse glass fibers, for example, having a diameter from 10 μm to 20 μm. In a third preferred embodiment there are both organic fibers that are hydrophobic relative to the electrolyte, when surfactant-free, and large diameter glass fibers, in addition to glass fibers having an average diameter less than 5 μm. The invention is also a recombinant storage battery comprising a plurality of electrodes in a closed case, a fibrous sheet separator as described in the preceding paragraph between adjacent ones of the electrodes, and a body of an electrolyte to which the sheet separators are inert is absorbed by each of the separators and maintained in contact with the adjacent ones of the electrodes. The invention is also a method for producing a recombinant storage battery. The method comprises the steps of assembling a plurality of electrodes with a sheet separator as described above between adjacent ones of the electrodes in a case having an opening in at least one wall, introducing a quantity of an electrolyte sufficient to cover the electrodes into the case, removing electrolyte that is not absorbed by the sheet separators, the plates, and other internal surfaces that are wetted by the electrolyte, and closing the case. If desired, the case can be evacuated partially before the electrolyte is introduced; in fact, this is usually desirable to increase the rate at which the cells are filled. In a preferred embodiment of the method, the battery is formed while the electrolyte covers the electrodes. In another preferred embodiment a portion of the electrolyte that is not retained by the separators, the plates and the internal surfaces that are wetted is left in the case, or all the electrolyte that is not retained is removed, and a desired amount of electrolyte is introduced before the case is closed so that, in either case, the battery contains absorbed electrolyte and a sump of electrolyte that is not absorbed. The electrolyte sump can be relatively small or relatively large, which is preferred depending upon the service for which the battery is intended. Finally, the invention is also a recombinant battery having an opening that is closed by a comparatively thin film of polyethylene, polypropylene, or other material that is more pervious to hydrogen than to oxygen. It has been found that the gas which necessitated the vents disclosed by McClelland et al. was mainly hydrogen and oxygen produced by electrolysis of water. It has also been found that the hydrogen is usually present in substantially greater than the stoichiometric proportion as a consequence of reaction of oxygen at the negative electrode, and that excess hydrogen can be vented through a thin film of polyethylene, polypropylene, or the like, in effect, removing water from the electrolyte until the recombination capability increases to such an extent that the excessive release of hydrogen ceases, and recombination prevents excessive pressure build-up. It has also been found that recombinant batteries having plate separators according to the invention are much less subject to hydrogen accumulation in service, even in the presence of free, unabsorbed electrolyte, than were previously known recombinant batteries, and that recombination occurs at an adequate rate in batteries with the instant separators from the very beginning of service, without any need for drying to increase recombination capability. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view, partially broken away, of a battery including separator material according to the invention. FIG. 2 is an enlarged schematic representation of a portion of the separator material in the battery illustrated in FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a single cell battery with a total of seven plates is indicated generally at 10. The battery 10 comprises three positive plates 12 which are electrically connected to a positive terminal 14 and four negative plates 16 electrically connected to a negative terminal 18. The plates 12 and 16 are housed within a battery case 20 which is covered by a top 22. An opening is defined in the top 22 by a boss 24. Separators 26 are positioned between each positive plate 12 and each negative plate 16. The separators 26 comprise sheets of separator material that are wrapped around the bottom of each positive plate 12 and cover both faces of each positive plate 12. Referring now to FIG. 2, the constituents of a separator 26 are schematically represented. The separator material comprises first fibers 28 which have an absorbency (as defined hereinbelow) for electrolyte which is high, i.e., greater than 90 percent, and further comprises second fibers 30 which have an absorbency for electrolyte which is low, i.e., less than 80 percent. The first and second fibers are combined in proportions which give the separator 26, when surfactant free, an absorbency with respect to an electrolyte of from 75 percent to 95 percent. Third fibers 32 (shown in phantom lines) comprising relatively large diameter glass fibers may be incorporated in the separator 26 to increase the resiliency thereof. Additional fibers 34 (shown in phantom lines) can be incorporated in the separator so long as the absorbency of the separator 26, when surfactant free, relative to an electrolyte is from 75 percent to 95 percent. A method according to the present invention for producing a recombinant battery comprises the steps of filling the battery case 20 containing the plates 12 and 16 and the separators 26 with a quantity of electrolyte sufficient to immerse the plates 12 and 16 and the separators 26, forming the battery 10 by charging, dumping excess electrolyte and sealing the battery case 20 by inserting a cap (not shown) into the opening defining by the boss 24 to close the battery 10. As demonstrated in the examples which follow, the invention is readily applied to multiple cell batteries. The invention will be more fully understood from the following examples, which are presented solely for the purpose of illustrating and disclosing, and are not to be construed as limiting. EXAMPLE 1 A fibrous sheet plate separator material was produced from 5 parts Grade 210 glass fibers, 2 parts Grade 206 glass fibers, 1 part Grade A-20BC chopped glass strand, 0.7 part Grade A-121 polyethylene fibers and approximately 0.06 part sulfuric acid, specific gravity 1,835, to lower the pH of a slurry that is produced to about 3. The glass fibers used are all commercially available from Manville; the grade 206 and the grade 210 fibers are marketed under the trade designation TEMPSTRAN for use in producing battery separators. They are made from an acid resistant borosilicate glass. The grade 206 fibers have a surface area of 1.80 m 2 per g, a fiber diameter of 0.85 μm. The grade 210 fibers have a surface area of 0.47 m 2 per g, a fiber diameter of 3.25 μm. The polyethylene fibers used are commercially available from hercules under the trade designation PULPEX A-121. They have an average length from 0.6 to 1.2 mm, maximum 2.0, and an average diameter from 10 to 20 μm. The glass and polyethylene fibers, the sulfuric acid and about 250 parts water were charged to a paper-making pulper, and the charge was beat for about 5 minutes to disperse the fibers without causing breakage. The resulting dispersion was diluted with about 250 parts water, and the diluted dispersion was then pumped to a chest at the head of a Fourdrinier paper making machine and flowed onto the screen of the machine to produce a separator material having a basis weight of 200 g per m 2 . A Group 26 battery was built with 13 plates per cell consisting of 7 negative plates and 6 positive plates having cast grids containing approximately 0.4 percent tin and 0.07 percent calcium, balance lead. Each plate was 5.625 inches wide and 4.75 inches tall. The positive plates were 0.057 inch thick, while the negative plates were 0.051 inch thick. Sheets of separator material produced as described above, 10.5 inches long and 6.22 inches wide, were folded around the positive plates so that the fold was at the bottom of the plate, leaving separator material extending about 1/2 inch above the positive plates and about 0.3 inch beyond each side of the positive plates. Each stack of 13 plates with the separator material between adjacent plates was inserted into a cell having a rib-to-rib dimension of 1.184 inches, so that each layer of separator material was compressed to 0.040 inch between plates. The assembly was completed by making the intercell connections and sealing a cover on the battery container. The cells were filled with a sulfuric acid electrolyte to a level about one inch above the tops of the plates. The electrolyte was made by adding 15 g/l sodium sulfate to sulfuric acid which had a specific gravity of 1.235. The battery was then formed; excess electrolyte was dumped; and the battery was sealed. EXAMPLE 2 A battery was produced by the procedure of Example 1, except that the charge to the pulper was 5.5 parts Grade 210 glass fibers, 3.5 parts Grade 206 glass fibers, 1 part A-20BC chopped glass strand, 0.06 part sulfuric acid and 250 parts water. EXAMPLE 3 A battery was produced by the procedure of Example 2, except that negative plates having expanded metal grids were used. For purposes of comparison, but not according to the instant invention, a control battery was produced by the procedure of Example 1, except that the charge to the pulper was 5 parts Grade 210 glass fibers, 2.5 parts Grade 206 glass fibers. 0.06 part sulfuric acid and 250 parts water. Average values were determined for batteries produced by the foregoing procedures of dry battery weight in g, drained battery weight in g, acid retained in g, acid absorbed by plates in g, acid retained by separators in ml, total separator volume in ml (calculated from the known dimensions), separator void volume in ml (calculated from the total separator volume and the calculated volumes of the fibers in the separator material) and percent v/v unfilled voids in the separator. These average values are set forth in the following table. ______________________________________ Example Number 1 2 3 Control______________________________________Dry Battery weight 11,716 11,716 10,957 11,736Drained Battery weight 14,414 14,335 13,977 15,107Acid Retained 2,794 2,618 3,020 3,371Acid Absorbed by Plates 1,141 1,143 1,243 1,232Acid retained by Separators 1,272 1,165 1,377 1,600Total Separator volume 1,648 1,666 1,652 1,678Separator void volume 1,523 1,533 1,527 1,540Percent v/v unfilled voids 16.5 24.0 10.5 0.0______________________________________ Referring to the foregoing table, the term "absorbency", as used herein and in the appended claims, is expressed in percent, is determined by the procedure described above, and is 100 minus the percent v/v unfilled voids. Batteries produced as described in Example 1 have been field tested in automotive service. They perform satisfactorily without excessive venting of gas, and without excessive pressure build up, indicating that oxygen formed at the positive plates is able to migrate through the separators to the negative plates for electrolytic recombination. Batteries produced by the control method, however, have been found to be unsatisfactory. There is an excessive pressure build-up, requiring that gas be vented and indicating that oxygen is not able to migrate through the separators to the negative plates. Actual test data from field testing of batteries produced as described in Example 1 indicate that they ca be used with computer controlled alternators which, in normal operation, subject the battery to highcurrent charging during braking; although there may be some gas build-up as a consequence of such charging, excessive pressures should not develop, and recombination should occur quickly once the high current charging ceases. Batteries according to the invention can be operated in any position and can be built in many shapes that were not feasible with conventional batteries. There is significantly less explosion hazard with batteries according to the invention than with conventional batteries that are not recombinant. Batteries produced as described in Examples 1, 2 and 3 and control batteries have been tested to compare the rates at which oxygen gas released at the positive plates was recombined at the negative plates. The test involved charging electrolyte-flooded, six-cell batteries for 16 hours at a constant voltage of 13.8 volts. During charging, a water bath was used to maintain the battery temperatures at 11°. The charging current was measured at the end of the 16 hour charging period. The majority of the free electrolyte in the batteries was then drained quickly, leaving only the small amount of unabsorbed electrolyte that was trapped within cavities in the cover and wetting the surfaces of the internal cell parts. The drained batteries were then sealed, fitted with pressure relief valves and again charged for 16 hours at 13.8 volts and 11°. The charging current was also determined at the end of the second 16 hours of charging. The term "Recombination Current" is subsequently used herein to mean the charging current at the end of the second 16 hours of charging minus that at the end of the first 16 hours of charging. The Recombination Current is related to the sum of the rate at which oxygen gas is being released at the positive plates and the rate at which oxygen gas is being recombined at the negative plates. Average values of Recombination Current are given in the following table for batteries produced as described in Examples 1-3 and for control batteries. ______________________________________ Recombination Current, milliamperes______________________________________Example 1 87Example 2 99Example 3 92Control -7______________________________________ The test described above for determining Recombination Current and the data in the foregoing table give a qualitative indication that batteries produced in accordance with the instant invention exhibit far better recombination performance than the Control battery. However, that test does not take into account the effect of the partial pressure of oxygen on recombination. Accordingly, an additional test was performed on the batteries produced in accordance with the foregoing examples to provide a more nearly quantitative measure of the performance of the batteries in terms of recombination. It has been observed that the rate of recombination of oxygen in a battery is a direct function of oxygen partial pressure in the battery case. In accordance with the test, a charging voltage is applied to a fully charged battery while a stream of nitrogen is caused to flow therethrough in contact with the plates, separator and electrolyte. The current drawn by the battery is measured. The stream of nitrogen virtually precludes recombination because oxygen must be available in order for recombination to occur. When the partial pressure of oxygen in a battery case drops to zero, so does the rate of recombination. After the current drawn by the battery under the flow of nitrogen is measured, the nitrogen stream is replaced with air and the charging voltage is again applied to the battery, and the current drawn by the battery is measured again. The difference between the two measurements is referred to hereafter as the "Recombining Current". A Recombining Current of zero occurs when oxygen is not being recombined. Five batteries produced in accordance with the procedure of Example 2 were found to have an average Recombining Current of 138 milliamperes. EXAMPLES 4A AND 4B Batteries were produced by the procedure of Example 1, except that the charge to the pulper was 386 kg of a mixture comprising 64 percent Grade 210 glass fibers, 26 percent Grade 206 glass fibers, 5 percent A-20BC chopped glass strand and 5 percent A-121 polypropylene fibers, 22,609 kg of water, and sulfuric acid in an amount sufficient to lower the pH of the charge to approximately 2.6. In the case of Example 4a, the basis weight of the separator material was 220 g per m 2 and in the case of Example 4b, the basis weight of the separator material was 200 g per m 2 . Values were determined for two batteries produced by the procedure of Example 4 of dry battery weight in g, drained battery weight in g, acid retained in g, acid absorbed but plates in g, acid retained by separators in ml, total separator volume in ml (calculated from the known dimensions), separator void volume in ml (calculated from the total separator volume and the calculated volumes of the fibers in the separator material) and percent v/v unfilled voids in the separator. These values are set forth in the following table. ______________________________________ Example Number 4a 4b______________________________________Dry Battery weight 11,757 11,741Drained Battery weight 14,617 14,564Acid Retained 2,860 2,823Acid Absorbed by Plates 1,061 1,062Acid retained by Separators 1,410 1,380Total Separator volume 1,680 1,674Separator void volume 1,532 1,540Percent v/v unfilled voids 8.0 10.4______________________________________ The Recombining Current was determined for batteries produced as described in Examples 4a and 4b at several different electrolyte volumes. Just before these determinations were made, the batteries were refilled with electrolyte so that the plates in each cell were submerged; the excess electrolyte was then dumped, and a first determination of the Recombining Current was made. Next, several additions of electrolyte were made to each battery, and second and subsequent determinations of Recombining Current were made, one after each addition. It will be appreciated that the first determinations of Recombining Current were made when the plates and the separator materials were saturated with electrolyte and that the second and subsequent determinations were made when there was excess electrolyte beyond that required to saturate the plates and the separator materials. The Recombining Current for each of these tests is set forth in the following table, together with the amount (if any) of electrolyte added after the excess was first dumped: ______________________________________ RECOMBINING CURRENT (milliamperes)Electrolyte added to Battery of Battery ofEach Cell (ml) Example 4a Example 4b______________________________________ 0 549 49810 226 --20 124 --25 -- 16030 64 --40 8 --50 3* 1175 -- -7*______________________________________ *Since the test is accurate to only about ±4 milliamperes, these value probably should be considered to be zero. The batteries of Examples 4a and 4b exhibited recombining currents of 549 and 498 milliamperes, respectively, after they were filled with electrolyte so that the plates were submerged and the excess electrolyte was dumped. They continued to exhibit substantial recombining currents even after the electrolyte level was increased beyond the amount that the plates and the separators could hold. For purposes of comparison, but not in accordance with the instant invention, Recombining Current was measured on several batteries, some made from separator material which is currently in commercial use, and some that are commercially available recombinant batteries. The purpose of the test was to evaluate the necessity for using what McClelland et al. calls a "starved amount" of electrolyte in recombinant batteries containing conventional separator material. In some cases the batteries tested contained separator material composed of 65 percent of Grade 210 fibers and 35 percent of Grade 206 fibers; in other cases the batteries were commercially available, made with separator material which is believed to have been composed of 60 to 65 percent of Grade 210 fibers and 35 to 40 percent of Grade 206 fibers. All of the batteries tested contained a conventional sulfuric acid electrolyte containing about 1 percent of sodium sulfate. The amount of electrolyte in the batteries varied from 87.9 to 100 percent of the amount required to fill the voids in the plates and the separators. The amount of electrolyte required to fill the voids was calculated from available data about the absorptiveness of the separator material and the plates. In other words, at 100 percent, the separator material and the plates were saturated but there was no excess electrolyte in the cells of the battery. The data concerning electrolyte levels and recombining currents is set forth below: ______________________________________ELECTROLYTE LEVELpercentv/v of plateand separator RECOMBINING CURRENTsaturation milliamperes______________________________________100 098.4 8897.2 22994.9 76092.6 74990.2 107887.9 1591______________________________________ The data in the table above demonstrates that the quantity of electrolyte in each cell of a recombinant battery with conventional separator material is critical with respect to the rate of recombination. Indeed, as the quantity of electrolyte in each cell of such a battery approaches 100 percent of the amount which would saturate the separator material and the plates, the rate of recombination approaches zero. In contrast, as shown by the data set forth in respect of the batteries produced in accordance with the procedure of Example 4, recombination occurs at a relatively rapid rate even when the electrolyte level in each cell exceeds the amount corresponding with 100 percent saturation of the plates and the separator material. The excessive pressure build-up of control batteries can be relieved by vents of the kind disclosed by McClelland et al. or, according to another aspect of the instant invention, by assembling the battery so that a comparatively thin film of polyethylene, polypropylene, or the like is the only closure for an opening through the case. Such a film, because polyethylene and polypropylene are pervious to hydrogen to a much greater extent than they are pervious to oxygen, enables the preferential release of hydrogen from the interior of the battery, discharging the battery. This preferential release of hydrogen continues until an electrochemical balance is reached, after which time the excessive release of hydrogen, oxygen or both stops. It has been found that a vent opening having an area of 65 cm 2 closed by a polyethylene film 0.025 mm thick is capable of preferential venting of hydrogen as required from a 40 ampere hour control battery in ordinary automotive service. It will be appreciated that various changes and modifications can be made from the detailed description herein without departing from the spirit and scope of the invention as defined in the following claims.
A fibrous sheet useful as a battery plate separator is disclosed. The sheet, in a specific embodiment, is made from a mixture of Grade 210 glass fibers, Grade 206 glass fibers, Grade A-20 chopped glass strand, and Grade A-121 polyethylene fibers. The fine glass fibers impart a high absorbency to the sheet; the coarse glass fibers impart a lower absorbency; and the polyethylene fibers, which are hydrophobic, are essentially non-absorbent. The different fibers are used in such proportions that the sheet has the absorbency, usually from 75 to 95 percent, required for use in a recombinant battery, even in the presence of free electrolyte. A recombinant battery in which fibrous sheets as described above serve as plate separators is also disclosed, as is a method for producing a recombinant battery which includes the steps of assembling a plurality of electrodes with such sheet separators in a case, flooding the electrodes in the case with an electrolyte, removing electrolyte that is not absorbed by the sheet separators from the case, and closing the case. Finally, a recombinant battery in a case which has an opening is also disclosed; the opening is closed by a thin film of polyethylene or the like through which hydrogen can escape at a faster rate than oxygen.
3
BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to aerosol containers and aerosol packaging, and is specifically directed to an actuator for aerosol containers having a rod which extends there from which allows the dispensation of aerosol materials through the rod. Various materials are contained within and dispensed by means of aerosol packaging. Numerous compositions are placed within aerosol containers, which are typically metal cans, and by means of an aerosol propellant under pressure, are discharged through a valve located on the aerosol container. Typically, the aerosol valve is crimped to the top of the aerosol container or can. The aerosol valve has a stem, which is typically a plastic straw, extending through a shoulder of the valve. As the stem is depressed, the valve opens, causing the contents which are under pressure to be dispensed from the aerosol container. The aerosol valve, and more precisely, the stem of the aerosol valve, is depressed and actuated by what is known as an aerosol actuator. This aerosol actuator is typically a plastic button which rests on top of the valve, and has a seat which contacts the valve stem. The actuator may be depressed by manual means, such as a finger, or mechanical means. As the actuator is depressed, a seat of the actuator contacts the valve stem, and causes depression of the valve stem. The aerosol contents are then dispensed through the valve stem and into the actuator, which has an orifice, commonly a nozzle, through which the contents are expelled from the package. As the actuator is released, the valve is closed by spring biasing. In certain applications, it is desirable to dispense aerosol compositions or materials through an applicator which may be from several inches to a few feet in length. A common example is the dispensation of insecticides which are contained within aerosol packaging. Insecticides may be dispensed into ant mounds by inserting an applicator rod into the ant mound, and dispensing insecticide within that closed environment. Likewise, insecticides may be dispensed into hornet's nests. Such processes are more fully described in Query, et al, U.S. Pat. No. 4,160,336, Query, et al, U.S. Pat. No. 4,534,128, and Query et al, U.S. Pat. No. 4,624,070. In other applications, the use of a rod to dispense aerosol contents may be desirable, since a rod may be inserted into a container, or a rod may be used for more precise placement of the material from a greater distance. A problem which is experienced with the use of such rods is the tendency of the rod to cause the actuator to pull away from the top of the aerosol container and the valve. When a rod is mounted to an actuator of the type known in the art, the moment about the point of the aerosol valve is easily sufficient to cause the actuator to pull loose from the valve, even when the force applied at the opposite end of the rod is small. The effect is similar to the use of a bottle opener with a bottle cap which is press fit to the top of the bottle The bottle cap is easily displaced by the use of a lever applied to the bottle cap. Since the moment resulting from the use of a rod one meter or more in length, is great, the aerosol actuator as known in the art will tend to separate from the container as the end of the rod is placed into, for example, an ant mound. The present invention yields an aerosol actuator which will not release from the container when normal force is applied to the end of the rod. Further, the actuator button of the device as disclosed herein does not directly contact the actuator body, but is hinged upon a straw which extends from the rod and actuator body. The use of the straw securely retains the actuator button, but gives superior feel and control in dispensing the aerosol contents over actuators found in the prior art. The present invention also provides a locking means to prevent accidental discharge of the aerosol contents. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the actuator exploded away from the top of the aerosol container, showing the locking pin removed from the actuator. FIG. 2 is a perspective view of the actuator body, with the actuator button removed therefrom, and with the orifice of the actuator shown as a phantom. FIG. 3 is a side sectioned view of the aerosol actuator attached to the top of an aerosol container. FIG. 4 is a side, sectioned view of the aerosol actuator shown in FIG. 3, with a locking pin in place to prevent use of the actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A typical aerosol container is shown in FIGS. 1 and 3. A can or cylinder 2, which is typically made of metal, has a valve 4 on one end thereof. This valve is crimped to an opening in the can 2 with the opening being typically circular. The top of the can itself has a shoulder 8, and adjacent thereto is the valve crimp 6. Rising from the center of the valve is a valve stem 10, which passes through the valve shoulder 12. Between the valve crimp 6 and the valve shoulder 12 is a depression within the valve 14. As the valve stem 10 is depressed the valve is opened, releasing the aerosol contents, which are under pressure, from the aerosol container. The valve stem is depressed by an actuator button 16, through which the released aerosol composition passes as it is received from the valve stem 10. In the preferred embodiment, the aerosol actuator is used with an applicator, which is a rod 18. This applicator rod 18 is of no particular length, but may be as shown in FIG. 1, and is of sufficient length to dispense the aerosol composition into the ground. The rod extends from the actuator body 20 to direct the aerosol composition through the rod. The aerosol composition escapes from the end of the rod opposite the actuator body. A nozzle 22 may be attached to the end of the rod. The nozzle may be of any typical configuration, having one or more orifices 24 therein. The rod may be one piece, or may be sectional as illustrated in FIG. 1. Joints 26 may be used to attach sections of the rod together for convenient transportation and storage of the rod. The major components of the device are illustrated in FIG. 2. An actuator body 20 is present, into which an actuator button 16 is inserted. The rod 18 extends from one side of the actuator body. A straw 28 extends from the rod toward the center of the actuator body. The actuator button 16 is then placed in a concentric fashion within the actuator body 20, but is not directly in contact with the actuator body. The actuator button is connected to the actuator body by the straw. The actuator button has an orifice 30 therein, which is concentric with the actuator button and the actuator body at the point of contact with the valve stem, and which extends through the actuator button so as to allow the straw to be inserted into this orifice of the actuator button. FIG. 3 is a sectioned view which shows the relationship of the various elements, including the aerosol container, and the operation of each. The actuator body has an inner ring 34 and an intermediate ring 36. The intermediate ring 36 is typically thinner than the inner ring 34, and as the intermediate ring is forced into the cavity 14 of the valve, it deforms slightly so as to apply pressure at the point of the valve crimp 6. The inner ring is of greater thickness, and does not deform to the extent to which the inner ring does, but contacts the shoulder of the valve to stabilize the actuator body, and to aid the intermediate ring in holding the actuator body in place. The actuator body has an outer ring 38 which rests against the shoulder 8 of the can. This outer ring further stabilizes the actuator body. As a force is placed on the end 22 of the rod, the moment about the actuator body is relatively great. Downward or upward movement of the end of the rod forces the outer ring against the can shoulder, preventing movement of the actuator body which, in conjunction with the intermediate ring and inner ring, prevents the actuator from being pried loose from the aerosol container. The actuator body has a cavity 40 therein. Concentric with the cavity is a additional void 42 which extends through the center of the actuator body. The valve stem 10 of the can extends through this concentric void and into the cavity of the actuator body. The actuator button 16 is placed into the cavity 40 of the actuator body. The actuator button has little, if any, direct contact with the actuator body. FIGS. 3,4. The seat 44 of the actuator button 16 contacts and receives the valve stem 10 so as to be able to depress it, but is connected to the actuator body by means of straw 28. The rod is inserted into a portion of the actuator body in which a horizontal void is present. The straw is inserted into a void within the rod so as to connect the orifice 46 of the rod with the orifice 30 of the actuator button. The straw 28 acts as a conduit to pass the aerosol composition from the orifice 30 to the rod, and it connects the actuator button with the actuator body and the rod. Additionally the straw 28 acts as a hinge for the actuator button as it is displaced within the actuator body to depress valve stem 10. As the actuator button 16 is displaced downwardly, it depresses the valve stem 10. This causes the valve to open, and the aerosol composition is released from the aerosol container. The aerosol composition then passes through the orifice of the actuator button, through the straw, and into the rod, from which the aerosol composition is dispensed through the nozzle. The seat 44 of the actuator button where it contacts the valve stem may be chamfered so as to readily accept the valve stem. Ribs may be formed within the orifice of the actuator button which receives the straw to insure an air tight fit between the straw and the actuator button. The straw may be made of any material, which allows it to deform slightly to insure a tight seal, while also acting as a hinge. The actuator button may be easily removed from the actuator body. Typically, in assembling the device, the actuator body, is pressed into place over the aerosol container. The actuator button is then placed within the actuator body which has already been assembled to the can. The actuator button may then be depressed to release the aerosol composition from the aerosol container. The device may be provided with a locking means. This locking means may be a void which is present within the actuator body, and which extends through to the cavity in which the actuator button is placed. Locking pin 48 is then inserted into the void 50, and extends into the cavity between the actuator button and the actuator body to prevent inadvertent displacement of the actuator button so as to depress the valve stem.
An aerosol actuator, with applicator, which inhibits the actuator from being separated by the aerosol container when a force is applied to the actuator by the applicator. An actuator button is mounted within an actuator body by a straw which connects the actuator body and applicator to the actuator button, and which acts as a hinge for the actuator button. The actuator body is designed to remain intact on the aerosol body when a force is applied to the end of the applicator by various support rings.
1
BACKGROUND OF THE INVENTION [0001] Liquid crystals (LC) consist of anisotropic molecules. The average direction of the long molecular axes is called the director, d. Reorientation of the director caused by the application of an external electric field is the basis of operation of most LC devices. The basic unit of LC devices is a LC cell, which consists of two substrates with LC material sandwiched in between. [0002] The sensitivity of a LC material to an applied electric field is determined by the dielectric anisotropy, Δε a , and spontaneous polarization, P. P has a nonzero value only for some chiral smectic LC phases. The higher the Δε a and P, the lower are the operating voltage and the faster the electro-optical response of the LC device and thereby, the faster the switching time between light and dark states of the LC cell. [0003] Nematic LC's are the most commonly used LC materials. Their electro-optical response is typically related to the square of the electric field. To increase Δε a and P, multi-component LC mixtures have been developed and special molecular dopants have been synthesized. This approach is extremely laborious and very expensive. [0004] Ferroelectric particles are particles which have a spontaneous electric polarization that is reversible by an electric field. It is known that the sensitivity of isotropic liquids to an applied electric field can be increased by doping with ultra-fine (less than 1 micrometer (μm) size) ferroelectric particles. For example, Bachmann and Bärner showed that ferroelectric BaTiO 3 particles that have been finely milled in the presence of surfactant will form a stable suspension in heptane (“Stable Suspensions of Ferroelectric BaTiO3-Particles,” Solid State Communications , 68(9), 865-869 (1988)). The particles had an average radius of about 10 nm. The birefringence of the suspension, which is impossible to achieve in a pure heptane matrix, was controlled by application of an electric field. [0005] Müller and Badmer suggested that a radius of approximately 20 nm was the size distribution cut-off for BaTiO 3 particles for maintaining a permanent dipole moment, with only smaller particles maintaining the permanent dipole moment (“Polydisperse Suspensions of BaTiO 3 -Particles,” Ferroelectrics , 108,83-88 (1990)). More recently, Schurian and Bärner produced stable ferroelectric suspensions of nanometer sized particles of LiNbO 3 and PbTiO 3 in a hydrocarbon carrier. These suspensions displayed similar birefringence to that of BaTiO 3 suspensions. Ferroelectric particles having an average radius of about 10-15 nanometers (nm) were determined to carry a permanent dipole moment of about 2000 Debye (De). Suspensions of nanometer size ferroelectric particles were also created by Schurian et al. by a method which included chemical precipitation of the particles and the use of alternate stabilizers ( Journal of Electrostatics , 40 & 41, 205-210 (1997)). [0006] None of these studies however, examined the behavior of ferroelectric particles in a suspension of liquid crystal or other anisotropic material. BRIEF SUMMARY OF THE INVENTION [0007] It is, therefore, an aspect of the present invention to provide a liquid crystal cell with a fast response time and low voltage requirements utilizing a suspension of ferroelectric particles in a liquid crystal material. It is another aspect of the present invention to provide a method of making a liquid crystal cell containing a suspension of ferroelectric particles in a liquid crystal material. [0008] This invention provides a liquid crystal device consisting of ferro-particles suspended in a liquid crystal (LC) material and a method for fabricating a light-modulating device utilizing this suspension. [0009] At least one or more of the foregoing aspects, together with the advantages thereof over the known art relating to liquid crystal displays (LCDs), which shall become apparent from the specification which follows, are accomplished by the invention as herein after described and claimed. [0010] In general, the present invention provides a liquid crystal device comprising ferroelectric particles suspended in a liquid crystal material. The liquid crystal device may additionally contain a polymer disposed in the suspension of ferroelectric particles and liquid crystal material. The present invention may be useful as an electro-optical device or as an information display device. The device may also contain a pair of opposed substrates, each substrate having an electrode facing the other substrate, with the ferroelectric particles suspended in a liquid crystal material disposed between the substrates. The device may optionally contain an alignment material disposed on one or both of the electrodes. [0011] The present invention also provides a method for fabricating a light-modulating device. The method comprises the steps of providing a pair of substrates with a cell gap therebetween and electrodes disposed on at least one facing surface of the substrates, and permanently disposing a suspension of ferroelectric particles in a liquid crystal material into the cell gap. [0012] The present invention also provides a method of generating an image. The method includes providing a pair of substrates with a cell gap therebetween, providing a transparent electrode on at least one of the substrates adjacent to said cell gap, permanently disposing a suspension of ferroelectric particles in a liquid crystal material within the cell gap; and applying an electric field across the electrodes. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0013] [0013]FIG. 1 is a graph showing the dependence of the transmission of a twist cell filled with ferroelectric particle/LC K15 suspension (circles) and pure LC (squares) on the applied ac-voltage; [0014] [0014]FIG. 2 is a graph showing the time-off characteristic the twist cell filled with ferroelectric particle/LC K15 suspension and pure LC K15; [0015] [0015]FIG. 3 is a graph showing the time-on characteristic the twist cell filled with ferroelectric particle/LC K15 suspension and pure LC K15; and [0016] [0016]FIG. 4 is a graph showing the dependence of the transmittance of the twist cell filled with ferroelectric particle/LC 4801 suspension and pure LC 4801 on the applied ac-voltage. [0017] [0017]FIG. 5A is a graph showing the dependence of the effective dielectric constant ε eff on the applied field of a ferroelectric particle LC suspension and pure LC. [0018] [0018]FIG. 5B is a graph showing the dependence of the effective dielectric constant ε eff on the applied field of a ferroelectric particle LC suspension and pure LC within a narrower range than that of FIG. 5A. [0019] [0019]FIG. 6 is a graph comparing the threshold voltage as a function of temperature for cells filled with the suspension of the present invention and cells filled with pure liquid crystal. [0020] [0020]FIG. 7A is a schematic representation of a suspension of ferroelectric particles in a liquid crystal according to the present invention in the absence of an electric field. [0021] [0021]FIG. 7B is a schematic representation of a suspension of ferroelectric particles in a liquid crystal according to the present invention in the presence of a direct current electric field. [0022] [0022]FIG. 8A is a schematic representation of a cell according to one embodiment of the present invention, wherein an ac-field is applied in the plane of the cell and a dc-field is applied perpendicular to the plane of the cell. [0023] [0023]FIG. 8B is a graph showing the dependence of the linear component of the electro-optic response of the suspension and the pure LC as a function of the applied ac-voltage for different values of the polarizing dc-field. DETAILED DESCRIPTION OF THE INVENTION [0024] The present invention is directed toward liquid crystal device consisting of ferro-particles suspended in a liquid crystal (LC) material. The liquid crystal device can be used for information displays, electro-optical devices, telecommunication systems and optical processing. To stabilize the suspension, a polymer network may be included in the suspension. The ferroelectric LC suspensions possess advanced electro-optic characteristics in comparison to traditional materials and devices. [0025] In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention pertains. [0026] In the present invention, ultra-fine ferroelectric particles are added to a LC material to improve and control the electro-optical characteristics. Optimally, the ferroelectric particles are smaller than the limits of unaided human vision, thereby providing increased speed and sensitivity to an electric field without harming the appearance of a LCD. The particle should also be small enough to incorporate into the LC matrix without disturbing the orientation of the LC. Typically, the particles are, on average, smaller than 1 μm in any dimension, preferably 0.5 μm or less. In one particular example, the particles have an average diameter of about 200 nm or less. In another example, the particles have an average diameter of about 20 nm or less. In still another example, the particles have an average diameter of about 10 nm. [0027] Ferroelectric particles possess an extra high dielectric anisotropy, Δε ferro , and have a spontaneous polarization, P, at temperatures less than the Curie temperature (T Curie ), the temperature at which the spontaneous polarization of ferroelectric material disappears. The Curie temperature will vary with the ferroelectric material. For example, T Curie for BaTiO 3 is about 108° C., while for Sn 2 P 2 S 6 , T Curie ≈66° C. [0028] Owing to their anisotropic properties, ferro-particles are orientationally ordered in the anisotropic LC matrix. Although not wishing to condition patentability on any particular theory, it is believed that interaction between the particles' surface and the director of the LC causes a collective response of the suspension to an applied electric field. The effective value of the dielectric anisotropy of the suspension can be roughly estimated as Δε eff susp ≈Δε+C·Δε ferro , where C is the volume ratio of ferro-particles to LC matrix. Since the value Δε ferro can be of the order of 10 3 -10 4 and the value Δε is of the order of 10, one can produce Δε eff susp of a value up to about 100 for C=10 −1 -10 −2 . The added particles therefore decrease the operating voltage of LC devices and increase the switching speed of the LC suspension. [0029] Application of an electric field may align the suspension of ferro-particles in the nematic LC due to dipole ordering of the ferro-particles. In this case, in addition to the dielectric quadratic response proportional to Δε susp E 2 , a linear electric response proportional to P·E appears. It results in a faster response and lower driving voltage of the suspension. [0030] The basic procedure of producing a suspension of ferroelectric particles in a LC may include the following steps: [0031] 1. Milling of the ferroelectric material. Grains of ferroelectric powder are mixed with a slow evaporating liquid carrier (e.g. heptane, kerosene etc) and a surfactant agent. The mixture is milled until an ultra-fine size of the particles covered with the surfactant molecules is obtained. [0032] 2. Fractionalation of the suspension in a liquid carrier. After milling the mixtures largest particles were removed by sedimentation. The homogeneous fraction of the resulting suspension is segregated in a column where particles of different size are separated by gravity forces. [0033] 3. Producing of the suspension in a liquid crystal. The suspension in a liquid carrier is mixed with a liquid crystal (it could be any kind of thermotropic LC which is miscible with the carrier) followed by evaporating of the carrier. [0034] 4. Additional stabilization of the suspension. Including a polymer network may additionally stabilize the resulting suspension. For example, a photopolymerizable material is added to the suspension and an LC cell filled with the suspension is irradiated with UV light. In another example, a polymerizable material is added to the suspension and phase separation of the polymerizable material is induced, such as by cooling, with subsequent or concurrent polymerization of the polymerizable material. [0035] The procedure can be varied in details. For example, the grain of ferro-particles can be mixed with a surfactant without liquid carrier, and a LC matrix itself can serve as a liquid carrier. [0036] Any type of LC material may be used in the suspension of this invention. Although examples are presented using nematic liquid crystal material, the invention is not limited thereto. Accordingly, the LC may be selected from other types of liquid crystal material including nematic, chiral nematic, and smectic liquid crystal materials, among others. [0037] As mentioned above, ferroelectric particles are particles which have a spontaneous electric polarization that is reversible by an electric field. Any particle that has this property may be utilized in the present invention. Suitable ferroelectric particles include particles of LiNbO 3 , PbTiO 3 , BaTiO 3 , and Sn 2 P 2 S 6 . Other particles may also be used provided that they exhibit a spontaneous electric polarization. [0038] The ferroelectric particles may be present in the suspension in an amount which permits the ferroelectric particles to be suspended without significant aggregation of the particles. This will, at least in part, depend on the surfactant or other material used to prevent aggregation. In one example, the ferroelectric particles are suspended in the liquid crystal material at a percentage of about 4 percent by weight or less compared to the liquid crystal material. In another example, the ferroelectric particles are suspended in the liquid crystal material at a percentage of about 1 percent by weight or less compared to the liquid crystal material. In still another example, the ferroelectric particles are suspended in the liquid crystal material at a percentage of about 0.5 percent by weight or less compared to the liquid crystal material. [0039] The suspension of ferroelectric particles in a liquid crystal material may additionally comprise a polymerizable material. The polymerizable material may be polymerized within the cell. When a polymerizable material is present, the method of the present invention additionally comprises the step of inducing polymerization of the polymerizable material. The method may additionally comprise the step of inducing phase separation of the polymer and liquid crystal material, for example, by cooling the mixture. [0040] In creating a liquid crystal cell according to the present invention, the ferroelectric particle/LC suspension may be disposed between a pair of facing substrates, at least one of which is transparent. The cell may also contain an electrode disposed on the facing surface of each of the substrates to produce an electric field within the cell. The electrodes also may be transparent, such as those made of indium or indium tin oxide (ITO). The electrodes can be continuous on the surface of the substrate, or they may be interdigitated. The substrates may additionally comprise an alignment layer on the facing surface of the substrate. [0041] To demonstrate the effectiveness of the present invention, several ferroelectric particle suspensions in liquid crystal material were made as follows. The following examples should not be viewed as limiting the scope of the invention. The claims will serve to define the inventions. [0042] Ferroelectric powder CTBS-3 from Physics-Chemystry Institute of Donetsc (National Academy of Sciences of Ukraine), having a characteristic grain size of 1 μm, and ε≈2300, was mixed with a solution of oleic acid as surfactant (Aldrich) in heptane in a weight ratio of 1:2:10. The mixture was dispersed in an ultrasonic dispergator (UZDH-2T) at a frequency (ν) of 22 kH, and power (P) of 400 W for 2 minutes, followed by milling in a vibration mill (Fritsch Pulaerisette) for 100 hours. [0043] The resulting suspension was poured into a glass column and allowed to segregate for 1 day by size. The faction of the suspension containing particles less than about 0.5 μm was removed and mixed with the LC, 4-4′-pentylcyanobiphenyl (available as K15 from EM Industries), at a weight proportion of 1:100. This mixture was dispersed in an ultrasonic dispergator for 5 minutes followed by evaporation of the heptane with a forevacuum pump. The resulting suspension contained about 0.5 weight percent ferro-particles in the LC matrix. [0044] The resulting suspension was tested in a LC twist cell. The LC twist cell consisted of two glass substrates and the suspension disposed between the substrates. The facing surfaces of the substrates were covered with an indium tin oxide (ITO) transparent electrode. The electrodes were covered with rubbed alignment layers consisting of NISSAN 7792 polyimide from Nisssan. A droplet of the suspension was put on one of the substrates and the second substrate was placed onto the first substrate. The substrates were separated by rigid 20 μm spacers and were oriented such that the rubbing directions of the polyimide layers were perpendicular to each other. The twist cell then was sealed with epoxy glue. [0045] The electro-optic characteristics of the twist cell were measured by a standard methods in the art (see, for example, Blinov and Chigrinov, Electrooptic Effects in Liquid Crystal Materials , Springer-Verlag, NY, 1994). These methods are integrated in Electro-Optic Measurements (EOM) software package developed in Dr. Phil Bos' research group at the Liquid Crystal Institute, Kent State University. The cell was put between crossed polarizers, and the directions of rubbing of the aligning layers were either parallel or perpendicular to the polarizer axes (normally black mode). An electric field (frequency, ν=1 kH) was applied to the ITO-electrodes of the cell and the dependence of the transparency of the system, T, on the applied voltage, V, was measured. In addition, the change of the transmission after abrupt switching on and switching off of an electric field was measured. [0046] The results obtained for the ferroelectric particle/LC suspension and an identical cell filled with pure LC are presented in FIGS. 1 - 3 . FIGS. 1 - 3 show that doping the LC with ferro-particles lowers the driving voltage and reduces the response time of the LC cell. FIG. 1 shows that the threshold of the Friedericksz transition, V F , defined as the voltage required to achieve 10% of the maximum transmittance (T max ) from a dark state decreases from 2.9 V to 2.2 V. As shown in FIG. 2, the decay time, defined as the time necessary to relax from T max to 10% of T max , decreased from 140 ms to 40 ms. FIG. 3 shows that the rise time, that is, the time necessary to achieve 90% of T max from a dark state, decreased from 9.5 ms to 5.5 ms. [0047] Ferroelectric powder Sn 2 P 2 S 6 (characteristic grain size 1 μm, ε≈400 was mixed with oleic acid surfactant (Aldrich) in a weight ratio of 1:2. The mixture was dispersed in an ultrasonic dispergator (UZDH-2T) (ν=22 kH, P=400 W) for 2 minutes followed by milling in a vibration mill (Fritsch Pulaerisette) for 118 hours. [0048] The resulting powder of ferroelectric particles treated with oleic acid was mixed with the LC material ZLI 4801-000, available from Merck, in a weight proportion of 1:100. This mixture was dispersed in the ultrasonic dispergator (frequency ν=22 kH, power P=400 W) for 5 minutes. The resulting suspension contained about 1% weight percent of ferro-particles in LC matrix. The suspension was tested in a LC twist cell produced as described above. [0049] The dependence of the transparency of the system, T, on the applied voltage, V, is presented in FIG. 4. The characteristics obtained for the same cell filled with pure ZLI 4801 are also presented in the FIG. 4. As in the case of LC K15, the doping of the LC with ferro-particles lowers the driving voltage and reduces the response time of the LC cell. The threshold of the Freederiks transition, V F , decreases from 2.6 V to 2 V. [0050] In another example, we obtained small (˜10 nm) ferro-electric Sn 2 P 2 S 6 particles by milling larger particles (about 1 mm size). The larger ferro-electric particles were mixed with a solution of oleic acid (surfactant) in heptane in a weight ratio of 1:2:10 respectively, ultrasonically dispersed and ground in a vibration mill for 120 hours. The resulting ferro-electric particle suspension was mixed with the LC. The heptane was then evaporated and the mixture was ultrasonically dispersed for 5 min. The relative concentrations of components were adjusted to give a final suspension with about 0.3% by volume of ferro-particles. [0051] Planar cells were filled with the LC suspension or pure LC at a temperature (T) greater than the clearing temperature (T c ). The clearing temperature is the temperature at or above which the liquid crystal material enters an isotropic liquid state and becomes transparent. The cells consisted of two ITO coated glass substrates with a rubbed polyimide layer assembled for parallel alignment. Calibrated, rod-like 5 μm polymer spacers controlled cell spacing. [0052] Cells with the ferroelectric particle/LC suspension had identical alignment qualities as cells with pure LC. Within experimental error, the measured value of the pretilt angle was the same for both cells (3.5±0.5° C.). Also, the clearing temperature points, T c , of the suspensions and the LCs were essentially the same, with the T c , for the pure LC (T c,LC ) being 92.3° C., while the T c , for the ferroelectric particle/LC suspension (T c,susp ) being 92.6° C. [0053] The increase in the dielectric anisotropy of the suspension was verified by comparing the electro-optical response of the planar cell filled with the pure LC ZLI-4801 and a ferroelectric particle suspension with the same LC. The dependence of the effective dielectric constant ε eff of the LC on the applied field is shown in FIGS. 5A and 5B. FIG. 5A is a graph showing ε eff of a ferroelectric particle LC suspension and pure LC over an applied field range of up to about 3 V/μm. FIG. 5B shows ε eff up to about 0.5 V/μm. FIGS. 5A and 5B show that the threshold voltage of the Freedericksz transition for the suspension (V th susp ) is about 0.91V, which is about half that for the pure LC (V th LC ), 1.87V. [0054] Sn 2 P 2 S 6 has a low Curie temperature, T Curie ≈66° C., which is below the clearing temperature, T c , of many nematic liquid crystal mixtures. For example, the nematic LC mixture ZLI-4801 (Merck) has a T c =93° C. [0055] The influence of the ferroelectric particles on the LC material is clearly revealed by the change in the electro-optic response with temperature. The pure LC threshold voltage gradually decreases with temperature because of the weak temperature dependence of K/ε LC ·(T). The threshold voltage for the suspension also decreases with temperature because of the weak temperature dependence of K/ε LC ·(T). However, the unique dielectric properties of the ferro-electric/LC suspensions become apparent at the Curie temperature of the Sn 2 P 2 S 6 , where the threshold voltage for the suspension changes abruptly, as shown in FIG. 6. This is believed to be the result of the critical behavior of the dielectric anisotropy at this temperature. An experimental value of the Curie temperature determined from FIG. 6 was about 66° C., which is exactly the same as that determined for the bulk Sn 2 P 2 S 6 crystals. [0056] While not wishing to condition patentability on any particular theory of operation of the present invention, one theory of operation is shown in FIGS. 7A and 7B. The permanent dipoles in the LC/particle suspension are believed to be randomly aligned in a head to tail fashion (FIG. 7A). Therefore, in order to realize the ferro-electric properties of the particles, we applied a large dc-electric field, sufficient to break the symmetry and align the particle dipoles along the field (FIG. 7B). A low frequency ac-field applied perpendicular to the dc field rotates the particles right or left depending on the sign of the applied field. The resulting linear component of the electro-optic response of the suspension will be proportional to both the polarizing, dc-, and the deflecting ac-fields. [0057] To demonstrate the unusual linear response of a nematic LC to an electric vector we studied the electro-optic response of a liquid-crystal cell composed of one substrate with a continuous ITO conducting surface and one with interdigitated ITO electrodes with a 1 millimeter (mm) distance between lines allowing application of an in-plane field. Both substrates were identically treated for homeotropic alignment of 4-4′-pentylcyanobiphenyl (5CB). An ac-field E ac (0-100V over a distance of 1 mm, 1 kHz) was applied in the plane of the cell and the dc-field E dc (0-30V over a distance of 10 μm) was applied perpendicular to the plane of the cell (along the director of the suspension). The voltage of the ac-field was below the voltage of the Freedericksz transition. A schematic representation of such a cell is shown in FIG. 8A. The ac-field is applied in the plane of the cell and the dc-field is applied perpendicular to the plane of the cell (along the director of the suspension). [0058] Light from a He-Ne laser was passed through a polarizer, the cell, a crossed analyzer and then into a photodiode detector. The beam was narrow enough to pass through the 1 mm inter-electrode gap in the cell. The cell was tilted at 45° with respect to the beam and the interdigitated electrodes are aligned 45° to the beam polarization direction. The detector output, proportional to the total light intensity (I), was fed into a lock-in amplifier referenced to the ac driving voltage U ac (w). The key to this experiment is the 45° angle of the cell relative to the beam, producing a different optical retardation for right or left rotation of the suspension resulting from opposite signs of the ac field. [0059] The dependence of the linear component of the electro-optic response of the suspension and the pure LC as a function of the applied ac-voltage (n=200 Hz) for different values of the polarizing dc-field is shown in FIG. 8B. The pure LC responds only to the magnitude and not the sign of the field for the whole dc field range and therefore shows no response in this arrangement. There was also no linear response of the suspension when no dc-field was applied. Application of the dc-field resulted in appearance of the sign-sensitive component of the electro-optical response, which increased proportionally to both the magnitude of the dc- and the ac-field. Switching off of the dc-field resulted in the fast disappearance of the linear response, and is believed to be caused by the disordering of the ferro-electric particles by thermal fluctuation. In this way, the present invention provides a liquid crystal suspension that responds not only to the direction of the field but to the sign of the field as well. It is envisioned that the present invention will be useful in bistable displays, wherein the display state of a cell may be switched rapidly from one state to another by changing the polarity of the applied field. [0060] The examples given above are intended to be illustrative only and the present invention was not limited to the conditions and materials noted therein. Various modifications can be achieved within the technical scope of the present invention. For example, the ferroelectric LC suspensions are not limited to a nematic matrix. Cholesteric LC's and any kind of smectic LC can be a base of ferroelectric/LC suspensions. Also, ferroelectric/LC suspensions can be used as a LC material in Polymer Dispersed Liquid Crystal Devices.
A liquid crystal device comprises ferroelectric particles suspended in a liquid crystal material. A method for fabricating a light-modulating device is also disclosed. The method comprises the steps of providing a pair of substrates with a cell gap therebetween, wherein electrodes are disposed on the facing surfaces of the substrates, and permanently disposing a suspension of ferroelectric particles in a liquid crystal material into said cell gap. A method of generating an image comprises providing a pair of substrates with a cell gap therebetween, providing transparent electrodes on each of said substrates adjacent to the cell gap, permanently disposing a suspension of ferroelectric particles in a liquid crystal material within the cell gap, and applying an electric field across the electrodes.
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